diff --git a/crypto/openssh/auth-pam.c b/crypto/openssh/auth-pam.c index 8425af1ea33a..bbd18e596951 100644 --- a/crypto/openssh/auth-pam.c +++ b/crypto/openssh/auth-pam.c @@ -1,1220 +1,1222 @@ /*- * Copyright (c) 2002 Networks Associates Technology, Inc. * All rights reserved. * * This software was developed for the FreeBSD Project by ThinkSec AS and * NAI Labs, the Security Research Division of Network Associates, Inc. * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the * DARPA CHATS research program. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * Copyright (c) 2003,2004 Damien Miller * Copyright (c) 2003,2004 Darren Tucker * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /* Based on FreeBSD: src/crypto/openssh/auth2-pam-freebsd.c,v 1.11 2003/03/31 13:48:18 des */ #include "includes.h" #include #include #include #include #include #include #include #include #ifdef USE_PAM #if defined(HAVE_SECURITY_PAM_APPL_H) #include #elif defined (HAVE_PAM_PAM_APPL_H) #include #endif /* OpenGroup RFC86.0 and XSSO specify no "const" on arguments */ #ifdef PAM_SUN_CODEBASE # define sshpam_const /* Solaris, HP-UX, AIX */ #else # define sshpam_const const /* LinuxPAM, OpenPAM */ #endif /* Ambiguity in spec: is it an array of pointers or a pointer to an array? */ #ifdef PAM_SUN_CODEBASE # define PAM_MSG_MEMBER(msg, n, member) ((*(msg))[(n)].member) #else # define PAM_MSG_MEMBER(msg, n, member) ((msg)[(n)]->member) #endif #include "xmalloc.h" #include "buffer.h" #include "key.h" #include "hostfile.h" #include "auth.h" #include "auth-pam.h" #include "canohost.h" #include "log.h" #include "msg.h" #include "packet.h" #include "misc.h" #include "servconf.h" #include "ssh2.h" #include "auth-options.h" #ifdef GSSAPI #include "ssh-gss.h" #endif #include "monitor_wrap.h" +#include "blacklist_client.h" extern ServerOptions options; extern Buffer loginmsg; extern int compat20; extern u_int utmp_len; /* so we don't silently change behaviour */ #ifdef USE_POSIX_THREADS # error "USE_POSIX_THREADS replaced by UNSUPPORTED_POSIX_THREADS_HACK" #endif /* * Formerly known as USE_POSIX_THREADS, using this is completely unsupported * and generally a bad idea. Use at own risk and do not expect support if * this breaks. */ #ifdef UNSUPPORTED_POSIX_THREADS_HACK #include /* * Avoid namespace clash when *not* using pthreads for systems *with* * pthreads, which unconditionally define pthread_t via sys/types.h * (e.g. Linux) */ typedef pthread_t sp_pthread_t; #else typedef pid_t sp_pthread_t; #endif struct pam_ctxt { sp_pthread_t pam_thread; int pam_psock; int pam_csock; int pam_done; }; static void sshpam_free_ctx(void *); static struct pam_ctxt *cleanup_ctxt; #ifndef UNSUPPORTED_POSIX_THREADS_HACK /* * Simulate threads with processes. */ static int sshpam_thread_status = -1; static mysig_t sshpam_oldsig; static void sshpam_sigchld_handler(int sig) { signal(SIGCHLD, SIG_DFL); if (cleanup_ctxt == NULL) return; /* handler called after PAM cleanup, shouldn't happen */ if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, WNOHANG) <= 0) { /* PAM thread has not exitted, privsep slave must have */ kill(cleanup_ctxt->pam_thread, SIGTERM); if (waitpid(cleanup_ctxt->pam_thread, &sshpam_thread_status, 0) <= 0) return; /* could not wait */ } if (WIFSIGNALED(sshpam_thread_status) && WTERMSIG(sshpam_thread_status) == SIGTERM) return; /* terminated by pthread_cancel */ if (!WIFEXITED(sshpam_thread_status)) sigdie("PAM: authentication thread exited unexpectedly"); if (WEXITSTATUS(sshpam_thread_status) != 0) sigdie("PAM: authentication thread exited uncleanly"); } /* ARGSUSED */ static void pthread_exit(void *value) { _exit(0); } /* ARGSUSED */ static int pthread_create(sp_pthread_t *thread, const void *attr, void *(*thread_start)(void *), void *arg) { pid_t pid; struct pam_ctxt *ctx = arg; sshpam_thread_status = -1; switch ((pid = fork())) { case -1: error("fork(): %s", strerror(errno)); return (-1); case 0: close(ctx->pam_psock); ctx->pam_psock = -1; thread_start(arg); _exit(1); default: *thread = pid; close(ctx->pam_csock); ctx->pam_csock = -1; sshpam_oldsig = signal(SIGCHLD, sshpam_sigchld_handler); return (0); } } static int pthread_cancel(sp_pthread_t thread) { signal(SIGCHLD, sshpam_oldsig); return (kill(thread, SIGTERM)); } /* ARGSUSED */ static int pthread_join(sp_pthread_t thread, void **value) { int status; if (sshpam_thread_status != -1) return (sshpam_thread_status); signal(SIGCHLD, sshpam_oldsig); waitpid(thread, &status, 0); return (status); } #endif static pam_handle_t *sshpam_handle = NULL; static int sshpam_err = 0; static int sshpam_authenticated = 0; static int sshpam_session_open = 0; static int sshpam_cred_established = 0; static int sshpam_account_status = -1; static char **sshpam_env = NULL; static Authctxt *sshpam_authctxt = NULL; static const char *sshpam_password = NULL; static char badpw[] = "\b\n\r\177INCORRECT"; /* Some PAM implementations don't implement this */ #ifndef HAVE_PAM_GETENVLIST static char ** pam_getenvlist(pam_handle_t *pamh) { /* * XXX - If necessary, we can still support envrionment passing * for platforms without pam_getenvlist by searching for known * env vars (e.g. KRB5CCNAME) from the PAM environment. */ return NULL; } #endif /* * Some platforms, notably Solaris, do not enforce password complexity * rules during pam_chauthtok() if the real uid of the calling process * is 0, on the assumption that it's being called by "passwd" run by root. * This wraps pam_chauthtok and sets/restore the real uid so PAM will do * the right thing. */ #ifdef SSHPAM_CHAUTHTOK_NEEDS_RUID static int sshpam_chauthtok_ruid(pam_handle_t *pamh, int flags) { int result; if (sshpam_authctxt == NULL) fatal("PAM: sshpam_authctxt not initialized"); if (setreuid(sshpam_authctxt->pw->pw_uid, -1) == -1) fatal("%s: setreuid failed: %s", __func__, strerror(errno)); result = pam_chauthtok(pamh, flags); if (setreuid(0, -1) == -1) fatal("%s: setreuid failed: %s", __func__, strerror(errno)); return result; } # define pam_chauthtok(a,b) (sshpam_chauthtok_ruid((a), (b))) #endif void sshpam_password_change_required(int reqd) { debug3("%s %d", __func__, reqd); if (sshpam_authctxt == NULL) fatal("%s: PAM authctxt not initialized", __func__); sshpam_authctxt->force_pwchange = reqd; if (reqd) { no_port_forwarding_flag |= 2; no_agent_forwarding_flag |= 2; no_x11_forwarding_flag |= 2; } else { no_port_forwarding_flag &= ~2; no_agent_forwarding_flag &= ~2; no_x11_forwarding_flag &= ~2; } } /* Import regular and PAM environment from subprocess */ static void import_environments(Buffer *b) { char *env; u_int i, num_env; int err; debug3("PAM: %s entering", __func__); #ifndef UNSUPPORTED_POSIX_THREADS_HACK /* Import variables set by do_pam_account */ sshpam_account_status = buffer_get_int(b); sshpam_password_change_required(buffer_get_int(b)); /* Import environment from subprocess */ num_env = buffer_get_int(b); if (num_env > 1024) fatal("%s: received %u environment variables, expected <= 1024", __func__, num_env); sshpam_env = xcalloc(num_env + 1, sizeof(*sshpam_env)); debug3("PAM: num env strings %d", num_env); for(i = 0; i < num_env; i++) sshpam_env[i] = buffer_get_string(b, NULL); sshpam_env[num_env] = NULL; /* Import PAM environment from subprocess */ num_env = buffer_get_int(b); debug("PAM: num PAM env strings %d", num_env); for(i = 0; i < num_env; i++) { env = buffer_get_string(b, NULL); #ifdef HAVE_PAM_PUTENV /* Errors are not fatal here */ if ((err = pam_putenv(sshpam_handle, env)) != PAM_SUCCESS) { error("PAM: pam_putenv: %s", pam_strerror(sshpam_handle, sshpam_err)); } #endif } #endif } /* * Conversation function for authentication thread. */ static int sshpam_thread_conv(int n, sshpam_const struct pam_message **msg, struct pam_response **resp, void *data) { Buffer buffer; struct pam_ctxt *ctxt; struct pam_response *reply; int i; debug3("PAM: %s entering, %d messages", __func__, n); *resp = NULL; if (data == NULL) { error("PAM: conversation function passed a null context"); return (PAM_CONV_ERR); } ctxt = data; if (n <= 0 || n > PAM_MAX_NUM_MSG) return (PAM_CONV_ERR); if ((reply = calloc(n, sizeof(*reply))) == NULL) return (PAM_CONV_ERR); buffer_init(&buffer); for (i = 0; i < n; ++i) { switch (PAM_MSG_MEMBER(msg, i, msg_style)) { case PAM_PROMPT_ECHO_OFF: buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg)); if (ssh_msg_send(ctxt->pam_csock, PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) goto fail; if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1) goto fail; if (buffer_get_char(&buffer) != PAM_AUTHTOK) goto fail; reply[i].resp = buffer_get_string(&buffer, NULL); break; case PAM_PROMPT_ECHO_ON: buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg)); if (ssh_msg_send(ctxt->pam_csock, PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) goto fail; if (ssh_msg_recv(ctxt->pam_csock, &buffer) == -1) goto fail; if (buffer_get_char(&buffer) != PAM_AUTHTOK) goto fail; reply[i].resp = buffer_get_string(&buffer, NULL); break; case PAM_ERROR_MSG: buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg)); if (ssh_msg_send(ctxt->pam_csock, PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) goto fail; break; case PAM_TEXT_INFO: buffer_put_cstring(&buffer, PAM_MSG_MEMBER(msg, i, msg)); if (ssh_msg_send(ctxt->pam_csock, PAM_MSG_MEMBER(msg, i, msg_style), &buffer) == -1) goto fail; break; default: goto fail; } buffer_clear(&buffer); } buffer_free(&buffer); *resp = reply; return (PAM_SUCCESS); fail: for(i = 0; i < n; i++) { free(reply[i].resp); } free(reply); buffer_free(&buffer); return (PAM_CONV_ERR); } /* * Authentication thread. */ static void * sshpam_thread(void *ctxtp) { struct pam_ctxt *ctxt = ctxtp; Buffer buffer; struct pam_conv sshpam_conv; int flags = (options.permit_empty_passwd == 0 ? PAM_DISALLOW_NULL_AUTHTOK : 0); #ifndef UNSUPPORTED_POSIX_THREADS_HACK extern char **environ; char **env_from_pam; u_int i; const char *pam_user; const char **ptr_pam_user = &pam_user; char *tz = getenv("TZ"); sshpam_err = pam_get_item(sshpam_handle, PAM_USER, (sshpam_const void **)ptr_pam_user); if (sshpam_err != PAM_SUCCESS) goto auth_fail; environ[0] = NULL; if (tz != NULL) if (setenv("TZ", tz, 1) == -1) error("PAM: could not set TZ environment: %s", strerror(errno)); if (sshpam_authctxt != NULL) { setproctitle("%s [pam]", sshpam_authctxt->valid ? pam_user : "unknown"); } #endif sshpam_conv.conv = sshpam_thread_conv; sshpam_conv.appdata_ptr = ctxt; if (sshpam_authctxt == NULL) fatal("%s: PAM authctxt not initialized", __func__); buffer_init(&buffer); sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, (const void *)&sshpam_conv); if (sshpam_err != PAM_SUCCESS) goto auth_fail; sshpam_err = pam_authenticate(sshpam_handle, flags); if (sshpam_err != PAM_SUCCESS) goto auth_fail; if (compat20) { if (!do_pam_account()) { sshpam_err = PAM_ACCT_EXPIRED; goto auth_fail; } if (sshpam_authctxt->force_pwchange) { sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK); if (sshpam_err != PAM_SUCCESS) goto auth_fail; sshpam_password_change_required(0); } } buffer_put_cstring(&buffer, "OK"); #ifndef UNSUPPORTED_POSIX_THREADS_HACK /* Export variables set by do_pam_account */ buffer_put_int(&buffer, sshpam_account_status); buffer_put_int(&buffer, sshpam_authctxt->force_pwchange); /* Export any environment strings set in child */ for(i = 0; environ[i] != NULL; i++) ; /* Count */ buffer_put_int(&buffer, i); for(i = 0; environ[i] != NULL; i++) buffer_put_cstring(&buffer, environ[i]); /* Export any environment strings set by PAM in child */ env_from_pam = pam_getenvlist(sshpam_handle); for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++) ; /* Count */ buffer_put_int(&buffer, i); for(i = 0; env_from_pam != NULL && env_from_pam[i] != NULL; i++) buffer_put_cstring(&buffer, env_from_pam[i]); #endif /* UNSUPPORTED_POSIX_THREADS_HACK */ /* XXX - can't do much about an error here */ ssh_msg_send(ctxt->pam_csock, sshpam_err, &buffer); buffer_free(&buffer); pthread_exit(NULL); auth_fail: buffer_put_cstring(&buffer, pam_strerror(sshpam_handle, sshpam_err)); /* XXX - can't do much about an error here */ if (sshpam_err == PAM_ACCT_EXPIRED) ssh_msg_send(ctxt->pam_csock, PAM_ACCT_EXPIRED, &buffer); else ssh_msg_send(ctxt->pam_csock, PAM_AUTH_ERR, &buffer); buffer_free(&buffer); pthread_exit(NULL); return (NULL); /* Avoid warning for non-pthread case */ } void sshpam_thread_cleanup(void) { struct pam_ctxt *ctxt = cleanup_ctxt; debug3("PAM: %s entering", __func__); if (ctxt != NULL && ctxt->pam_thread != 0) { pthread_cancel(ctxt->pam_thread); pthread_join(ctxt->pam_thread, NULL); close(ctxt->pam_psock); close(ctxt->pam_csock); memset(ctxt, 0, sizeof(*ctxt)); cleanup_ctxt = NULL; } } static int sshpam_null_conv(int n, sshpam_const struct pam_message **msg, struct pam_response **resp, void *data) { debug3("PAM: %s entering, %d messages", __func__, n); return (PAM_CONV_ERR); } static struct pam_conv null_conv = { sshpam_null_conv, NULL }; static int sshpam_store_conv(int n, sshpam_const struct pam_message **msg, struct pam_response **resp, void *data) { struct pam_response *reply; int i; size_t len; debug3("PAM: %s called with %d messages", __func__, n); *resp = NULL; if (n <= 0 || n > PAM_MAX_NUM_MSG) return (PAM_CONV_ERR); if ((reply = calloc(n, sizeof(*reply))) == NULL) return (PAM_CONV_ERR); for (i = 0; i < n; ++i) { switch (PAM_MSG_MEMBER(msg, i, msg_style)) { case PAM_ERROR_MSG: case PAM_TEXT_INFO: len = strlen(PAM_MSG_MEMBER(msg, i, msg)); buffer_append(&loginmsg, PAM_MSG_MEMBER(msg, i, msg), len); buffer_append(&loginmsg, "\n", 1 ); reply[i].resp_retcode = PAM_SUCCESS; break; default: goto fail; } } *resp = reply; return (PAM_SUCCESS); fail: for(i = 0; i < n; i++) { free(reply[i].resp); } free(reply); return (PAM_CONV_ERR); } static struct pam_conv store_conv = { sshpam_store_conv, NULL }; void sshpam_cleanup(void) { if (sshpam_handle == NULL || (use_privsep && !mm_is_monitor())) return; debug("PAM: cleanup"); pam_set_item(sshpam_handle, PAM_CONV, (const void *)&null_conv); if (sshpam_session_open) { debug("PAM: closing session"); pam_close_session(sshpam_handle, PAM_SILENT); sshpam_session_open = 0; } if (sshpam_cred_established) { debug("PAM: deleting credentials"); pam_setcred(sshpam_handle, PAM_DELETE_CRED); sshpam_cred_established = 0; } sshpam_authenticated = 0; pam_end(sshpam_handle, sshpam_err); sshpam_handle = NULL; } static int sshpam_init(Authctxt *authctxt) { extern char *__progname; const char *pam_rhost, *pam_user, *user = authctxt->user; const char **ptr_pam_user = &pam_user; if (sshpam_handle != NULL) { /* We already have a PAM context; check if the user matches */ sshpam_err = pam_get_item(sshpam_handle, PAM_USER, (sshpam_const void **)ptr_pam_user); if (sshpam_err == PAM_SUCCESS && strcmp(user, pam_user) == 0) return (0); pam_end(sshpam_handle, sshpam_err); sshpam_handle = NULL; } debug("PAM: initializing for \"%s\"", user); sshpam_err = pam_start(SSHD_PAM_SERVICE, user, &store_conv, &sshpam_handle); sshpam_authctxt = authctxt; if (sshpam_err != PAM_SUCCESS) { pam_end(sshpam_handle, sshpam_err); sshpam_handle = NULL; return (-1); } pam_rhost = get_remote_name_or_ip(utmp_len, options.use_dns); debug("PAM: setting PAM_RHOST to \"%s\"", pam_rhost); sshpam_err = pam_set_item(sshpam_handle, PAM_RHOST, pam_rhost); if (sshpam_err != PAM_SUCCESS) { pam_end(sshpam_handle, sshpam_err); sshpam_handle = NULL; return (-1); } #ifdef PAM_TTY_KLUDGE /* * Some silly PAM modules (e.g. pam_time) require a TTY to operate. * sshd doesn't set the tty until too late in the auth process and * may not even set one (for tty-less connections) */ debug("PAM: setting PAM_TTY to \"ssh\""); sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, "ssh"); if (sshpam_err != PAM_SUCCESS) { pam_end(sshpam_handle, sshpam_err); sshpam_handle = NULL; return (-1); } #endif return (0); } static void * sshpam_init_ctx(Authctxt *authctxt) { struct pam_ctxt *ctxt; int socks[2]; debug3("PAM: %s entering", __func__); /* * Refuse to start if we don't have PAM enabled or do_pam_account * has previously failed. */ if (!options.use_pam || sshpam_account_status == 0) return NULL; /* Initialize PAM */ if (sshpam_init(authctxt) == -1) { error("PAM: initialization failed"); return (NULL); } ctxt = xcalloc(1, sizeof *ctxt); /* Start the authentication thread */ if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, socks) == -1) { error("PAM: failed create sockets: %s", strerror(errno)); free(ctxt); return (NULL); } ctxt->pam_psock = socks[0]; ctxt->pam_csock = socks[1]; if (pthread_create(&ctxt->pam_thread, NULL, sshpam_thread, ctxt) == -1) { error("PAM: failed to start authentication thread: %s", strerror(errno)); close(socks[0]); close(socks[1]); free(ctxt); return (NULL); } cleanup_ctxt = ctxt; return (ctxt); } static int sshpam_query(void *ctx, char **name, char **info, u_int *num, char ***prompts, u_int **echo_on) { Buffer buffer; struct pam_ctxt *ctxt = ctx; size_t plen; u_char type; char *msg; size_t len, mlen; debug3("PAM: %s entering", __func__); buffer_init(&buffer); *name = xstrdup(""); *info = xstrdup(""); *prompts = xmalloc(sizeof(char *)); **prompts = NULL; plen = 0; *echo_on = xmalloc(sizeof(u_int)); while (ssh_msg_recv(ctxt->pam_psock, &buffer) == 0) { type = buffer_get_char(&buffer); msg = buffer_get_string(&buffer, NULL); mlen = strlen(msg); switch (type) { case PAM_PROMPT_ECHO_ON: case PAM_PROMPT_ECHO_OFF: *num = 1; len = plen + mlen + 1; **prompts = xreallocarray(**prompts, 1, len); strlcpy(**prompts + plen, msg, len - plen); plen += mlen; **echo_on = (type == PAM_PROMPT_ECHO_ON); free(msg); return (0); case PAM_ERROR_MSG: case PAM_TEXT_INFO: /* accumulate messages */ len = plen + mlen + 2; **prompts = xreallocarray(**prompts, 1, len); strlcpy(**prompts + plen, msg, len - plen); plen += mlen; strlcat(**prompts + plen, "\n", len - plen); plen++; free(msg); break; case PAM_ACCT_EXPIRED: sshpam_account_status = 0; /* FALLTHROUGH */ case PAM_AUTH_ERR: debug3("PAM: %s", pam_strerror(sshpam_handle, type)); if (**prompts != NULL && strlen(**prompts) != 0) { *info = **prompts; **prompts = NULL; *num = 0; **echo_on = 0; ctxt->pam_done = -1; free(msg); return 0; } /* FALLTHROUGH */ case PAM_SUCCESS: if (**prompts != NULL) { /* drain any accumulated messages */ debug("PAM: %s", **prompts); buffer_append(&loginmsg, **prompts, strlen(**prompts)); free(**prompts); **prompts = NULL; } if (type == PAM_SUCCESS) { if (!sshpam_authctxt->valid || (sshpam_authctxt->pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES)) fatal("Internal error: PAM auth " "succeeded when it should have " "failed"); import_environments(&buffer); *num = 0; **echo_on = 0; ctxt->pam_done = 1; free(msg); return (0); } + BLACKLIST_NOTIFY(BLACKLIST_AUTH_FAIL); error("PAM: %s for %s%.100s from %.100s", msg, sshpam_authctxt->valid ? "" : "illegal user ", sshpam_authctxt->user, get_remote_name_or_ip(utmp_len, options.use_dns)); /* FALLTHROUGH */ default: *num = 0; **echo_on = 0; free(msg); ctxt->pam_done = -1; return (-1); } } return (-1); } /* XXX - see also comment in auth-chall.c:verify_response */ static int sshpam_respond(void *ctx, u_int num, char **resp) { Buffer buffer; struct pam_ctxt *ctxt = ctx; debug2("PAM: %s entering, %u responses", __func__, num); switch (ctxt->pam_done) { case 1: sshpam_authenticated = 1; return (0); case 0: break; default: return (-1); } if (num != 1) { error("PAM: expected one response, got %u", num); return (-1); } buffer_init(&buffer); if (sshpam_authctxt->valid && (sshpam_authctxt->pw->pw_uid != 0 || options.permit_root_login == PERMIT_YES)) buffer_put_cstring(&buffer, *resp); else buffer_put_cstring(&buffer, badpw); if (ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, &buffer) == -1) { buffer_free(&buffer); return (-1); } buffer_free(&buffer); return (1); } static void sshpam_free_ctx(void *ctxtp) { struct pam_ctxt *ctxt = ctxtp; debug3("PAM: %s entering", __func__); sshpam_thread_cleanup(); free(ctxt); /* * We don't call sshpam_cleanup() here because we may need the PAM * handle at a later stage, e.g. when setting up a session. It's * still on the cleanup list, so pam_end() *will* be called before * the server process terminates. */ } KbdintDevice sshpam_device = { "pam", sshpam_init_ctx, sshpam_query, sshpam_respond, sshpam_free_ctx }; KbdintDevice mm_sshpam_device = { "pam", mm_sshpam_init_ctx, mm_sshpam_query, mm_sshpam_respond, mm_sshpam_free_ctx }; /* * This replaces auth-pam.c */ void start_pam(Authctxt *authctxt) { if (!options.use_pam) fatal("PAM: initialisation requested when UsePAM=no"); if (sshpam_init(authctxt) == -1) fatal("PAM: initialisation failed"); } void finish_pam(void) { sshpam_cleanup(); } u_int do_pam_account(void) { debug("%s: called", __func__); if (sshpam_account_status != -1) return (sshpam_account_status); sshpam_err = pam_acct_mgmt(sshpam_handle, 0); debug3("PAM: %s pam_acct_mgmt = %d (%s)", __func__, sshpam_err, pam_strerror(sshpam_handle, sshpam_err)); if (sshpam_err != PAM_SUCCESS && sshpam_err != PAM_NEW_AUTHTOK_REQD) { sshpam_account_status = 0; return (sshpam_account_status); } if (sshpam_err == PAM_NEW_AUTHTOK_REQD) sshpam_password_change_required(1); sshpam_account_status = 1; return (sshpam_account_status); } void do_pam_set_tty(const char *tty) { if (tty != NULL) { debug("PAM: setting PAM_TTY to \"%s\"", tty); sshpam_err = pam_set_item(sshpam_handle, PAM_TTY, tty); if (sshpam_err != PAM_SUCCESS) fatal("PAM: failed to set PAM_TTY: %s", pam_strerror(sshpam_handle, sshpam_err)); } } void do_pam_setcred(int init) { sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, (const void *)&store_conv); if (sshpam_err != PAM_SUCCESS) fatal("PAM: failed to set PAM_CONV: %s", pam_strerror(sshpam_handle, sshpam_err)); if (init) { debug("PAM: establishing credentials"); sshpam_err = pam_setcred(sshpam_handle, PAM_ESTABLISH_CRED); } else { debug("PAM: reinitializing credentials"); sshpam_err = pam_setcred(sshpam_handle, PAM_REINITIALIZE_CRED); } if (sshpam_err == PAM_SUCCESS) { sshpam_cred_established = 1; return; } if (sshpam_authenticated) fatal("PAM: pam_setcred(): %s", pam_strerror(sshpam_handle, sshpam_err)); else debug("PAM: pam_setcred(): %s", pam_strerror(sshpam_handle, sshpam_err)); } static int sshpam_tty_conv(int n, sshpam_const struct pam_message **msg, struct pam_response **resp, void *data) { char input[PAM_MAX_MSG_SIZE]; struct pam_response *reply; int i; debug3("PAM: %s called with %d messages", __func__, n); *resp = NULL; if (n <= 0 || n > PAM_MAX_NUM_MSG || !isatty(STDIN_FILENO)) return (PAM_CONV_ERR); if ((reply = calloc(n, sizeof(*reply))) == NULL) return (PAM_CONV_ERR); for (i = 0; i < n; ++i) { switch (PAM_MSG_MEMBER(msg, i, msg_style)) { case PAM_PROMPT_ECHO_OFF: reply[i].resp = read_passphrase(PAM_MSG_MEMBER(msg, i, msg), RP_ALLOW_STDIN); reply[i].resp_retcode = PAM_SUCCESS; break; case PAM_PROMPT_ECHO_ON: fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg)); if (fgets(input, sizeof input, stdin) == NULL) input[0] = '\0'; if ((reply[i].resp = strdup(input)) == NULL) goto fail; reply[i].resp_retcode = PAM_SUCCESS; break; case PAM_ERROR_MSG: case PAM_TEXT_INFO: fprintf(stderr, "%s\n", PAM_MSG_MEMBER(msg, i, msg)); reply[i].resp_retcode = PAM_SUCCESS; break; default: goto fail; } } *resp = reply; return (PAM_SUCCESS); fail: for(i = 0; i < n; i++) { free(reply[i].resp); } free(reply); return (PAM_CONV_ERR); } static struct pam_conv tty_conv = { sshpam_tty_conv, NULL }; /* * XXX this should be done in the authentication phase, but ssh1 doesn't * support that */ void do_pam_chauthtok(void) { if (use_privsep) fatal("Password expired (unable to change with privsep)"); sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, (const void *)&tty_conv); if (sshpam_err != PAM_SUCCESS) fatal("PAM: failed to set PAM_CONV: %s", pam_strerror(sshpam_handle, sshpam_err)); debug("PAM: changing password"); sshpam_err = pam_chauthtok(sshpam_handle, PAM_CHANGE_EXPIRED_AUTHTOK); if (sshpam_err != PAM_SUCCESS) fatal("PAM: pam_chauthtok(): %s", pam_strerror(sshpam_handle, sshpam_err)); } void do_pam_session(void) { debug3("PAM: opening session"); sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, (const void *)&store_conv); if (sshpam_err != PAM_SUCCESS) fatal("PAM: failed to set PAM_CONV: %s", pam_strerror(sshpam_handle, sshpam_err)); sshpam_err = pam_open_session(sshpam_handle, 0); if (sshpam_err == PAM_SUCCESS) sshpam_session_open = 1; else { sshpam_session_open = 0; disable_forwarding(); error("PAM: pam_open_session(): %s", pam_strerror(sshpam_handle, sshpam_err)); } } int is_pam_session_open(void) { return sshpam_session_open; } /* * Set a PAM environment string. We need to do this so that the session * modules can handle things like Kerberos/GSI credentials that appear * during the ssh authentication process. */ int do_pam_putenv(char *name, char *value) { int ret = 1; #ifdef HAVE_PAM_PUTENV char *compound; size_t len; len = strlen(name) + strlen(value) + 2; compound = xmalloc(len); snprintf(compound, len, "%s=%s", name, value); ret = pam_putenv(sshpam_handle, compound); free(compound); #endif return (ret); } char ** fetch_pam_child_environment(void) { return sshpam_env; } char ** fetch_pam_environment(void) { return (pam_getenvlist(sshpam_handle)); } void free_pam_environment(char **env) { char **envp; if (env == NULL) return; for (envp = env; *envp; envp++) free(*envp); free(env); } /* * "Blind" conversation function for password authentication. Assumes that * echo-off prompts are for the password and stores messages for later * display. */ static int sshpam_passwd_conv(int n, sshpam_const struct pam_message **msg, struct pam_response **resp, void *data) { struct pam_response *reply; int i; size_t len; debug3("PAM: %s called with %d messages", __func__, n); *resp = NULL; if (n <= 0 || n > PAM_MAX_NUM_MSG) return (PAM_CONV_ERR); if ((reply = calloc(n, sizeof(*reply))) == NULL) return (PAM_CONV_ERR); for (i = 0; i < n; ++i) { switch (PAM_MSG_MEMBER(msg, i, msg_style)) { case PAM_PROMPT_ECHO_OFF: if (sshpam_password == NULL) goto fail; if ((reply[i].resp = strdup(sshpam_password)) == NULL) goto fail; reply[i].resp_retcode = PAM_SUCCESS; break; case PAM_ERROR_MSG: case PAM_TEXT_INFO: len = strlen(PAM_MSG_MEMBER(msg, i, msg)); if (len > 0) { buffer_append(&loginmsg, PAM_MSG_MEMBER(msg, i, msg), len); buffer_append(&loginmsg, "\n", 1); } if ((reply[i].resp = strdup("")) == NULL) goto fail; reply[i].resp_retcode = PAM_SUCCESS; break; default: goto fail; } } *resp = reply; return (PAM_SUCCESS); fail: for(i = 0; i < n; i++) { free(reply[i].resp); } free(reply); return (PAM_CONV_ERR); } static struct pam_conv passwd_conv = { sshpam_passwd_conv, NULL }; /* * Attempt password authentication via PAM */ int sshpam_auth_passwd(Authctxt *authctxt, const char *password) { int flags = (options.permit_empty_passwd == 0 ? PAM_DISALLOW_NULL_AUTHTOK : 0); if (!options.use_pam || sshpam_handle == NULL) fatal("PAM: %s called when PAM disabled or failed to " "initialise.", __func__); sshpam_password = password; sshpam_authctxt = authctxt; /* * If the user logging in is invalid, or is root but is not permitted * by PermitRootLogin, use an invalid password to prevent leaking * information via timing (eg if the PAM config has a delay on fail). */ if (!authctxt->valid || (authctxt->pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES)) sshpam_password = badpw; sshpam_err = pam_set_item(sshpam_handle, PAM_CONV, (const void *)&passwd_conv); if (sshpam_err != PAM_SUCCESS) fatal("PAM: %s: failed to set PAM_CONV: %s", __func__, pam_strerror(sshpam_handle, sshpam_err)); sshpam_err = pam_authenticate(sshpam_handle, flags); sshpam_password = NULL; if (sshpam_err == PAM_SUCCESS && authctxt->valid) { debug("PAM: password authentication accepted for %.100s", authctxt->user); return 1; } else { debug("PAM: password authentication failed for %.100s: %s", authctxt->valid ? authctxt->user : "an illegal user", pam_strerror(sshpam_handle, sshpam_err)); return 0; } } #endif /* USE_PAM */ diff --git a/crypto/openssh/auth.c b/crypto/openssh/auth.c index ba908801a169..1259385f8af9 100644 --- a/crypto/openssh/auth.c +++ b/crypto/openssh/auth.c @@ -1,776 +1,781 @@ /* $OpenBSD: auth.c,v 1.113 2015/08/21 03:42:19 djm Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "includes.h" __RCSID("$FreeBSD$"); #include #include #include #include #include #ifdef HAVE_PATHS_H # include #endif #include #ifdef HAVE_LOGIN_H #include #endif #ifdef USE_SHADOW #include #endif #ifdef HAVE_LIBGEN_H #include #endif #include #include #include #include #include #include "xmalloc.h" #include "match.h" #include "groupaccess.h" #include "log.h" #include "buffer.h" #include "misc.h" #include "servconf.h" #include "key.h" #include "hostfile.h" #include "auth.h" #include "auth-options.h" #include "canohost.h" #include "uidswap.h" #include "packet.h" #include "loginrec.h" #ifdef GSSAPI #include "ssh-gss.h" #endif #include "authfile.h" #include "monitor_wrap.h" #include "authfile.h" #include "ssherr.h" #include "compat.h" +#include "blacklist_client.h" /* import */ extern ServerOptions options; extern int use_privsep; extern Buffer loginmsg; extern struct passwd *privsep_pw; /* Debugging messages */ Buffer auth_debug; int auth_debug_init; /* * Check if the user is allowed to log in via ssh. If user is listed * in DenyUsers or one of user's groups is listed in DenyGroups, false * will be returned. If AllowUsers isn't empty and user isn't listed * there, or if AllowGroups isn't empty and one of user's groups isn't * listed there, false will be returned. * If the user's shell is not executable, false will be returned. * Otherwise true is returned. */ int allowed_user(struct passwd * pw) { struct stat st; const char *hostname = NULL, *ipaddr = NULL, *passwd = NULL; u_int i; #ifdef USE_SHADOW struct spwd *spw = NULL; #endif /* Shouldn't be called if pw is NULL, but better safe than sorry... */ if (!pw || !pw->pw_name) return 0; #ifdef USE_SHADOW if (!options.use_pam) spw = getspnam(pw->pw_name); #ifdef HAS_SHADOW_EXPIRE if (!options.use_pam && spw != NULL && auth_shadow_acctexpired(spw)) return 0; #endif /* HAS_SHADOW_EXPIRE */ #endif /* USE_SHADOW */ /* grab passwd field for locked account check */ passwd = pw->pw_passwd; #ifdef USE_SHADOW if (spw != NULL) #ifdef USE_LIBIAF passwd = get_iaf_password(pw); #else passwd = spw->sp_pwdp; #endif /* USE_LIBIAF */ #endif /* check for locked account */ if (!options.use_pam && passwd && *passwd) { int locked = 0; #ifdef LOCKED_PASSWD_STRING if (strcmp(passwd, LOCKED_PASSWD_STRING) == 0) locked = 1; #endif #ifdef LOCKED_PASSWD_PREFIX if (strncmp(passwd, LOCKED_PASSWD_PREFIX, strlen(LOCKED_PASSWD_PREFIX)) == 0) locked = 1; #endif #ifdef LOCKED_PASSWD_SUBSTR if (strstr(passwd, LOCKED_PASSWD_SUBSTR)) locked = 1; #endif #ifdef USE_LIBIAF free((void *) passwd); #endif /* USE_LIBIAF */ if (locked) { logit("User %.100s not allowed because account is locked", pw->pw_name); return 0; } } /* * Deny if shell does not exist or is not executable unless we * are chrooting. */ if (options.chroot_directory == NULL || strcasecmp(options.chroot_directory, "none") == 0) { char *shell = xstrdup((pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell); /* empty = /bin/sh */ if (stat(shell, &st) != 0) { logit("User %.100s not allowed because shell %.100s " "does not exist", pw->pw_name, shell); free(shell); return 0; } if (S_ISREG(st.st_mode) == 0 || (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)) == 0) { logit("User %.100s not allowed because shell %.100s " "is not executable", pw->pw_name, shell); free(shell); return 0; } free(shell); } if (options.num_deny_users > 0 || options.num_allow_users > 0 || options.num_deny_groups > 0 || options.num_allow_groups > 0) { hostname = get_canonical_hostname(options.use_dns); ipaddr = get_remote_ipaddr(); } /* Return false if user is listed in DenyUsers */ if (options.num_deny_users > 0) { for (i = 0; i < options.num_deny_users; i++) if (match_user(pw->pw_name, hostname, ipaddr, options.deny_users[i])) { logit("User %.100s from %.100s not allowed " "because listed in DenyUsers", pw->pw_name, hostname); return 0; } } /* Return false if AllowUsers isn't empty and user isn't listed there */ if (options.num_allow_users > 0) { for (i = 0; i < options.num_allow_users; i++) if (match_user(pw->pw_name, hostname, ipaddr, options.allow_users[i])) break; /* i < options.num_allow_users iff we break for loop */ if (i >= options.num_allow_users) { logit("User %.100s from %.100s not allowed because " "not listed in AllowUsers", pw->pw_name, hostname); return 0; } } if (options.num_deny_groups > 0 || options.num_allow_groups > 0) { /* Get the user's group access list (primary and supplementary) */ if (ga_init(pw->pw_name, pw->pw_gid) == 0) { logit("User %.100s from %.100s not allowed because " "not in any group", pw->pw_name, hostname); return 0; } /* Return false if one of user's groups is listed in DenyGroups */ if (options.num_deny_groups > 0) if (ga_match(options.deny_groups, options.num_deny_groups)) { ga_free(); logit("User %.100s from %.100s not allowed " "because a group is listed in DenyGroups", pw->pw_name, hostname); return 0; } /* * Return false if AllowGroups isn't empty and one of user's groups * isn't listed there */ if (options.num_allow_groups > 0) if (!ga_match(options.allow_groups, options.num_allow_groups)) { ga_free(); logit("User %.100s from %.100s not allowed " "because none of user's groups are listed " "in AllowGroups", pw->pw_name, hostname); return 0; } ga_free(); } #ifdef CUSTOM_SYS_AUTH_ALLOWED_USER if (!sys_auth_allowed_user(pw, &loginmsg)) return 0; #endif /* We found no reason not to let this user try to log on... */ return 1; } void auth_info(Authctxt *authctxt, const char *fmt, ...) { va_list ap; int i; free(authctxt->info); authctxt->info = NULL; va_start(ap, fmt); i = vasprintf(&authctxt->info, fmt, ap); va_end(ap); if (i < 0 || authctxt->info == NULL) fatal("vasprintf failed"); } void auth_log(Authctxt *authctxt, int authenticated, int partial, const char *method, const char *submethod) { void (*authlog) (const char *fmt,...) = verbose; char *authmsg; if (use_privsep && !mm_is_monitor() && !authctxt->postponed) return; /* Raise logging level */ if (authenticated == 1 || !authctxt->valid || authctxt->failures >= options.max_authtries / 2 || strcmp(method, "password") == 0) authlog = logit; if (authctxt->postponed) authmsg = "Postponed"; else if (partial) authmsg = "Partial"; - else + else { authmsg = authenticated ? "Accepted" : "Failed"; + BLACKLIST_NOTIFY(authenticated ? + BLACKLIST_AUTH_OK : BLACKLIST_AUTH_FAIL); + } authlog("%s %s%s%s for %s%.100s from %.200s port %d %s%s%s", authmsg, method, submethod != NULL ? "/" : "", submethod == NULL ? "" : submethod, authctxt->valid ? "" : "invalid user ", authctxt->user, get_remote_ipaddr(), get_remote_port(), compat20 ? "ssh2" : "ssh1", authctxt->info != NULL ? ": " : "", authctxt->info != NULL ? authctxt->info : ""); free(authctxt->info); authctxt->info = NULL; #ifdef CUSTOM_FAILED_LOGIN if (authenticated == 0 && !authctxt->postponed && (strcmp(method, "password") == 0 || strncmp(method, "keyboard-interactive", 20) == 0 || strcmp(method, "challenge-response") == 0)) record_failed_login(authctxt->user, get_canonical_hostname(options.use_dns), "ssh"); # ifdef WITH_AIXAUTHENTICATE if (authenticated) sys_auth_record_login(authctxt->user, get_canonical_hostname(options.use_dns), "ssh", &loginmsg); # endif #endif #ifdef SSH_AUDIT_EVENTS if (authenticated == 0 && !authctxt->postponed) audit_event(audit_classify_auth(method)); #endif } void auth_maxtries_exceeded(Authctxt *authctxt) { error("maximum authentication attempts exceeded for " "%s%.100s from %.200s port %d %s", authctxt->valid ? "" : "invalid user ", authctxt->user, get_remote_ipaddr(), get_remote_port(), compat20 ? "ssh2" : "ssh1"); packet_disconnect("Too many authentication failures"); /* NOTREACHED */ } /* * Check whether root logins are disallowed. */ int auth_root_allowed(const char *method) { switch (options.permit_root_login) { case PERMIT_YES: return 1; case PERMIT_NO_PASSWD: if (strcmp(method, "publickey") == 0 || strcmp(method, "hostbased") == 0 || strcmp(method, "gssapi-with-mic") == 0) return 1; break; case PERMIT_FORCED_ONLY: if (forced_command) { logit("Root login accepted for forced command."); return 1; } break; } logit("ROOT LOGIN REFUSED FROM %.200s", get_remote_ipaddr()); return 0; } /* * Given a template and a passwd structure, build a filename * by substituting % tokenised options. Currently, %% becomes '%', * %h becomes the home directory and %u the username. * * This returns a buffer allocated by xmalloc. */ char * expand_authorized_keys(const char *filename, struct passwd *pw) { char *file, ret[PATH_MAX]; int i; file = percent_expand(filename, "h", pw->pw_dir, "u", pw->pw_name, (char *)NULL); /* * Ensure that filename starts anchored. If not, be backward * compatible and prepend the '%h/' */ if (*file == '/') return (file); i = snprintf(ret, sizeof(ret), "%s/%s", pw->pw_dir, file); if (i < 0 || (size_t)i >= sizeof(ret)) fatal("expand_authorized_keys: path too long"); free(file); return (xstrdup(ret)); } char * authorized_principals_file(struct passwd *pw) { if (options.authorized_principals_file == NULL) return NULL; return expand_authorized_keys(options.authorized_principals_file, pw); } /* return ok if key exists in sysfile or userfile */ HostStatus check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host, const char *sysfile, const char *userfile) { char *user_hostfile; struct stat st; HostStatus host_status; struct hostkeys *hostkeys; const struct hostkey_entry *found; hostkeys = init_hostkeys(); load_hostkeys(hostkeys, host, sysfile); if (userfile != NULL) { user_hostfile = tilde_expand_filename(userfile, pw->pw_uid); if (options.strict_modes && (stat(user_hostfile, &st) == 0) && ((st.st_uid != 0 && st.st_uid != pw->pw_uid) || (st.st_mode & 022) != 0)) { logit("Authentication refused for %.100s: " "bad owner or modes for %.200s", pw->pw_name, user_hostfile); auth_debug_add("Ignored %.200s: bad ownership or modes", user_hostfile); } else { temporarily_use_uid(pw); load_hostkeys(hostkeys, host, user_hostfile); restore_uid(); } free(user_hostfile); } host_status = check_key_in_hostkeys(hostkeys, key, &found); if (host_status == HOST_REVOKED) error("WARNING: revoked key for %s attempted authentication", found->host); else if (host_status == HOST_OK) debug("%s: key for %s found at %s:%ld", __func__, found->host, found->file, found->line); else debug("%s: key for host %s not found", __func__, host); free_hostkeys(hostkeys); return host_status; } /* * Check a given path for security. This is defined as all components * of the path to the file must be owned by either the owner of * of the file or root and no directories must be group or world writable. * * XXX Should any specific check be done for sym links ? * * Takes a file name, its stat information (preferably from fstat() to * avoid races), the uid of the expected owner, their home directory and an * error buffer plus max size as arguments. * * Returns 0 on success and -1 on failure */ int auth_secure_path(const char *name, struct stat *stp, const char *pw_dir, uid_t uid, char *err, size_t errlen) { char buf[PATH_MAX], homedir[PATH_MAX]; char *cp; int comparehome = 0; struct stat st; if (realpath(name, buf) == NULL) { snprintf(err, errlen, "realpath %s failed: %s", name, strerror(errno)); return -1; } if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL) comparehome = 1; if (!S_ISREG(stp->st_mode)) { snprintf(err, errlen, "%s is not a regular file", buf); return -1; } if ((!platform_sys_dir_uid(stp->st_uid) && stp->st_uid != uid) || (stp->st_mode & 022) != 0) { snprintf(err, errlen, "bad ownership or modes for file %s", buf); return -1; } /* for each component of the canonical path, walking upwards */ for (;;) { if ((cp = dirname(buf)) == NULL) { snprintf(err, errlen, "dirname() failed"); return -1; } strlcpy(buf, cp, sizeof(buf)); if (stat(buf, &st) < 0 || (!platform_sys_dir_uid(st.st_uid) && st.st_uid != uid) || (st.st_mode & 022) != 0) { snprintf(err, errlen, "bad ownership or modes for directory %s", buf); return -1; } /* If are past the homedir then we can stop */ if (comparehome && strcmp(homedir, buf) == 0) break; /* * dirname should always complete with a "/" path, * but we can be paranoid and check for "." too */ if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) break; } return 0; } /* * Version of secure_path() that accepts an open file descriptor to * avoid races. * * Returns 0 on success and -1 on failure */ static int secure_filename(FILE *f, const char *file, struct passwd *pw, char *err, size_t errlen) { struct stat st; /* check the open file to avoid races */ if (fstat(fileno(f), &st) < 0) { snprintf(err, errlen, "cannot stat file %s: %s", file, strerror(errno)); return -1; } return auth_secure_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen); } static FILE * auth_openfile(const char *file, struct passwd *pw, int strict_modes, int log_missing, char *file_type) { char line[1024]; struct stat st; int fd; FILE *f; if ((fd = open(file, O_RDONLY|O_NONBLOCK)) == -1) { if (log_missing || errno != ENOENT) debug("Could not open %s '%s': %s", file_type, file, strerror(errno)); return NULL; } if (fstat(fd, &st) < 0) { close(fd); return NULL; } if (!S_ISREG(st.st_mode)) { logit("User %s %s %s is not a regular file", pw->pw_name, file_type, file); close(fd); return NULL; } unset_nonblock(fd); if ((f = fdopen(fd, "r")) == NULL) { close(fd); return NULL; } if (strict_modes && secure_filename(f, file, pw, line, sizeof(line)) != 0) { fclose(f); logit("Authentication refused: %s", line); auth_debug_add("Ignored %s: %s", file_type, line); return NULL; } return f; } FILE * auth_openkeyfile(const char *file, struct passwd *pw, int strict_modes) { return auth_openfile(file, pw, strict_modes, 1, "authorized keys"); } FILE * auth_openprincipals(const char *file, struct passwd *pw, int strict_modes) { return auth_openfile(file, pw, strict_modes, 0, "authorized principals"); } struct passwd * getpwnamallow(const char *user) { #ifdef HAVE_LOGIN_CAP extern login_cap_t *lc; #ifdef BSD_AUTH auth_session_t *as; #endif #endif struct passwd *pw; struct connection_info *ci = get_connection_info(1, options.use_dns); ci->user = user; parse_server_match_config(&options, ci); #if defined(_AIX) && defined(HAVE_SETAUTHDB) aix_setauthdb(user); #endif pw = getpwnam(user); #if defined(_AIX) && defined(HAVE_SETAUTHDB) aix_restoreauthdb(); #endif #ifdef HAVE_CYGWIN /* * Windows usernames are case-insensitive. To avoid later problems * when trying to match the username, the user is only allowed to * login if the username is given in the same case as stored in the * user database. */ if (pw != NULL && strcmp(user, pw->pw_name) != 0) { logit("Login name %.100s does not match stored username %.100s", user, pw->pw_name); pw = NULL; } #endif if (pw == NULL) { + BLACKLIST_NOTIFY(BLACKLIST_AUTH_FAIL); logit("Invalid user %.100s from %.100s", user, get_remote_ipaddr()); #ifdef CUSTOM_FAILED_LOGIN record_failed_login(user, get_canonical_hostname(options.use_dns), "ssh"); #endif #ifdef SSH_AUDIT_EVENTS audit_event(SSH_INVALID_USER); #endif /* SSH_AUDIT_EVENTS */ return (NULL); } if (!allowed_user(pw)) return (NULL); #ifdef HAVE_LOGIN_CAP if ((lc = login_getpwclass(pw)) == NULL) { debug("unable to get login class: %s", user); return (NULL); } #ifdef BSD_AUTH if ((as = auth_open()) == NULL || auth_setpwd(as, pw) != 0 || auth_approval(as, lc, pw->pw_name, "ssh") <= 0) { debug("Approval failure for %s", user); pw = NULL; } if (as != NULL) auth_close(as); #endif #endif if (pw != NULL) return (pwcopy(pw)); return (NULL); } /* Returns 1 if key is revoked by revoked_keys_file, 0 otherwise */ int auth_key_is_revoked(Key *key) { char *fp = NULL; int r; if (options.revoked_keys_file == NULL) return 0; if ((fp = sshkey_fingerprint(key, options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) { r = SSH_ERR_ALLOC_FAIL; error("%s: fingerprint key: %s", __func__, ssh_err(r)); goto out; } r = sshkey_check_revoked(key, options.revoked_keys_file); switch (r) { case 0: break; /* not revoked */ case SSH_ERR_KEY_REVOKED: error("Authentication key %s %s revoked by file %s", sshkey_type(key), fp, options.revoked_keys_file); goto out; default: error("Error checking authentication key %s %s in " "revoked keys file %s: %s", sshkey_type(key), fp, options.revoked_keys_file, ssh_err(r)); goto out; } /* Success */ r = 0; out: free(fp); return r == 0 ? 0 : 1; } void auth_debug_add(const char *fmt,...) { char buf[1024]; va_list args; if (!auth_debug_init) return; va_start(args, fmt); vsnprintf(buf, sizeof(buf), fmt, args); va_end(args); buffer_put_cstring(&auth_debug, buf); } void auth_debug_send(void) { char *msg; if (!auth_debug_init) return; while (buffer_len(&auth_debug)) { msg = buffer_get_string(&auth_debug, NULL); packet_send_debug("%s", msg); free(msg); } } void auth_debug_reset(void) { if (auth_debug_init) buffer_clear(&auth_debug); else { buffer_init(&auth_debug); auth_debug_init = 1; } } struct passwd * fakepw(void) { static struct passwd fake; memset(&fake, 0, sizeof(fake)); fake.pw_name = "NOUSER"; fake.pw_passwd = "$2a$06$r3.juUaHZDlIbQaO2dS9FuYxL1W9M81R1Tc92PoSNmzvpEqLkLGrK"; #ifdef HAVE_STRUCT_PASSWD_PW_GECOS fake.pw_gecos = "NOUSER"; #endif fake.pw_uid = privsep_pw == NULL ? (uid_t)-1 : privsep_pw->pw_uid; fake.pw_gid = privsep_pw == NULL ? (gid_t)-1 : privsep_pw->pw_gid; #ifdef HAVE_STRUCT_PASSWD_PW_CLASS fake.pw_class = ""; #endif fake.pw_dir = "/nonexist"; fake.pw_shell = "/nonexist"; return (&fake); } diff --git a/crypto/openssh/auth1.c b/crypto/openssh/auth1.c index 5073c49bb37d..71eb0c21b260 100644 --- a/crypto/openssh/auth1.c +++ b/crypto/openssh/auth1.c @@ -1,444 +1,447 @@ /* $OpenBSD: auth1.c,v 1.82 2014/07/15 15:54:14 millert Exp $ */ /* * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved * * As far as I am concerned, the code I have written for this software * can be used freely for any purpose. Any derived versions of this * software must be clearly marked as such, and if the derived work is * incompatible with the protocol description in the RFC file, it must be * called by a name other than "ssh" or "Secure Shell". */ #include "includes.h" #ifdef WITH_SSH1 #include #include #include #include #include #include #include "openbsd-compat/sys-queue.h" #include "xmalloc.h" #include "rsa.h" #include "ssh1.h" #include "packet.h" #include "buffer.h" #include "log.h" #include "misc.h" #include "servconf.h" #include "compat.h" #include "key.h" #include "hostfile.h" #include "auth.h" #include "channels.h" #include "session.h" #include "uidswap.h" #ifdef GSSAPI #include "ssh-gss.h" #endif #include "monitor_wrap.h" #include "buffer.h" +#include "blacklist_client.h" /* import */ extern ServerOptions options; extern Buffer loginmsg; static int auth1_process_password(Authctxt *); static int auth1_process_rsa(Authctxt *); static int auth1_process_rhosts_rsa(Authctxt *); static int auth1_process_tis_challenge(Authctxt *); static int auth1_process_tis_response(Authctxt *); static char *client_user = NULL; /* Used to fill in remote user for PAM */ struct AuthMethod1 { int type; char *name; int *enabled; int (*method)(Authctxt *); }; const struct AuthMethod1 auth1_methods[] = { { SSH_CMSG_AUTH_PASSWORD, "password", &options.password_authentication, auth1_process_password }, { SSH_CMSG_AUTH_RSA, "rsa", &options.rsa_authentication, auth1_process_rsa }, { SSH_CMSG_AUTH_RHOSTS_RSA, "rhosts-rsa", &options.rhosts_rsa_authentication, auth1_process_rhosts_rsa }, { SSH_CMSG_AUTH_TIS, "challenge-response", &options.challenge_response_authentication, auth1_process_tis_challenge }, { SSH_CMSG_AUTH_TIS_RESPONSE, "challenge-response", &options.challenge_response_authentication, auth1_process_tis_response }, { -1, NULL, NULL, NULL} }; static const struct AuthMethod1 *lookup_authmethod1(int type) { int i; for (i = 0; auth1_methods[i].name != NULL; i++) if (auth1_methods[i].type == type) return (&(auth1_methods[i])); return (NULL); } static char * get_authname(int type) { const struct AuthMethod1 *a; static char buf[64]; if ((a = lookup_authmethod1(type)) != NULL) return (a->name); snprintf(buf, sizeof(buf), "bad-auth-msg-%d", type); return (buf); } /*ARGSUSED*/ static int auth1_process_password(Authctxt *authctxt) { int authenticated = 0; char *password; u_int dlen; /* * Read user password. It is in plain text, but was * transmitted over the encrypted channel so it is * not visible to an outside observer. */ password = packet_get_string(&dlen); packet_check_eom(); /* Try authentication with the password. */ authenticated = PRIVSEP(auth_password(authctxt, password)); explicit_bzero(password, dlen); free(password); return (authenticated); } /*ARGSUSED*/ static int auth1_process_rsa(Authctxt *authctxt) { int authenticated = 0; BIGNUM *n; /* RSA authentication requested. */ if ((n = BN_new()) == NULL) fatal("do_authloop: BN_new failed"); packet_get_bignum(n); packet_check_eom(); authenticated = auth_rsa(authctxt, n); BN_clear_free(n); return (authenticated); } /*ARGSUSED*/ static int auth1_process_rhosts_rsa(Authctxt *authctxt) { int keybits, authenticated = 0; u_int bits; Key *client_host_key; u_int ulen; /* * Get client user name. Note that we just have to * trust the client; root on the client machine can * claim to be any user. */ client_user = packet_get_cstring(&ulen); /* Get the client host key. */ client_host_key = key_new(KEY_RSA1); bits = packet_get_int(); packet_get_bignum(client_host_key->rsa->e); packet_get_bignum(client_host_key->rsa->n); keybits = BN_num_bits(client_host_key->rsa->n); if (keybits < 0 || bits != (u_int)keybits) { verbose("Warning: keysize mismatch for client_host_key: " "actual %d, announced %d", BN_num_bits(client_host_key->rsa->n), bits); } packet_check_eom(); authenticated = auth_rhosts_rsa(authctxt, client_user, client_host_key); key_free(client_host_key); auth_info(authctxt, "ruser %.100s", client_user); return (authenticated); } /*ARGSUSED*/ static int auth1_process_tis_challenge(Authctxt *authctxt) { char *challenge; if ((challenge = get_challenge(authctxt)) == NULL) return (0); debug("sending challenge '%s'", challenge); packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); packet_put_cstring(challenge); free(challenge); packet_send(); packet_write_wait(); return (-1); } /*ARGSUSED*/ static int auth1_process_tis_response(Authctxt *authctxt) { int authenticated = 0; char *response; u_int dlen; response = packet_get_string(&dlen); packet_check_eom(); authenticated = verify_response(authctxt, response); explicit_bzero(response, dlen); free(response); return (authenticated); } /* * read packets, try to authenticate the user and * return only if authentication is successful */ static void do_authloop(Authctxt *authctxt) { int authenticated = 0; int prev = 0, type = 0; const struct AuthMethod1 *meth; debug("Attempting authentication for %s%.100s.", authctxt->valid ? "" : "invalid user ", authctxt->user); /* If the user has no password, accept authentication immediately. */ if (options.permit_empty_passwd && options.password_authentication && #ifdef KRB5 (!options.kerberos_authentication || options.kerberos_or_local_passwd) && #endif PRIVSEP(auth_password(authctxt, ""))) { #ifdef USE_PAM if (options.use_pam && (PRIVSEP(do_pam_account()))) #endif { auth_log(authctxt, 1, 0, "without authentication", NULL); return; } } /* Indicate that authentication is needed. */ packet_start(SSH_SMSG_FAILURE); packet_send(); packet_write_wait(); for (;;) { /* default to fail */ authenticated = 0; /* Get a packet from the client. */ prev = type; type = packet_read(); /* * If we started challenge-response authentication but the * next packet is not a response to our challenge, release * the resources allocated by get_challenge() (which would * normally have been released by verify_response() had we * received such a response) */ if (prev == SSH_CMSG_AUTH_TIS && type != SSH_CMSG_AUTH_TIS_RESPONSE) abandon_challenge_response(authctxt); if (authctxt->failures >= options.max_authtries) goto skip; if ((meth = lookup_authmethod1(type)) == NULL) { logit("Unknown message during authentication: " "type %d", type); goto skip; } if (!*(meth->enabled)) { verbose("%s authentication disabled.", meth->name); goto skip; } authenticated = meth->method(authctxt); if (authenticated == -1) continue; /* "postponed" */ #ifdef BSD_AUTH if (authctxt->as) { auth_close(authctxt->as); authctxt->as = NULL; } #endif if (!authctxt->valid && authenticated) fatal("INTERNAL ERROR: authenticated invalid user %s", authctxt->user); #ifdef _UNICOS if (authenticated && cray_access_denied(authctxt->user)) { authenticated = 0; fatal("Access denied for user %s.",authctxt->user); } #endif /* _UNICOS */ #ifndef HAVE_CYGWIN /* Special handling for root */ if (authenticated && authctxt->pw->pw_uid == 0 && !auth_root_allowed(meth->name)) { authenticated = 0; # ifdef SSH_AUDIT_EVENTS PRIVSEP(audit_event(SSH_LOGIN_ROOT_DENIED)); # endif } #endif #ifdef USE_PAM if (options.use_pam && authenticated && !PRIVSEP(do_pam_account())) { char *msg; size_t len; + BLACKLIST_NOTIFY(BLACKLIST_AUTH_FAIL); error("Access denied for user %s by PAM account " "configuration", authctxt->user); len = buffer_len(&loginmsg); buffer_append(&loginmsg, "\0", 1); msg = buffer_ptr(&loginmsg); /* strip trailing newlines */ if (len > 0) while (len > 0 && msg[--len] == '\n') msg[len] = '\0'; else msg = "Access denied."; packet_disconnect("%s", msg); } #endif skip: /* Log before sending the reply */ auth_log(authctxt, authenticated, 0, get_authname(type), NULL); free(client_user); client_user = NULL; if (authenticated) return; if (++authctxt->failures >= options.max_authtries) { #ifdef SSH_AUDIT_EVENTS PRIVSEP(audit_event(SSH_LOGIN_EXCEED_MAXTRIES)); #endif auth_maxtries_exceeded(authctxt); } packet_start(SSH_SMSG_FAILURE); packet_send(); packet_write_wait(); } } /* * Performs authentication of an incoming connection. Session key has already * been exchanged and encryption is enabled. */ void do_authentication(Authctxt *authctxt) { u_int ulen; char *user, *style = NULL; /* Get the name of the user that we wish to log in as. */ packet_read_expect(SSH_CMSG_USER); /* Get the user name. */ user = packet_get_cstring(&ulen); packet_check_eom(); if ((style = strchr(user, ':')) != NULL) *style++ = '\0'; authctxt->user = user; authctxt->style = style; /* Verify that the user is a valid user. */ if ((authctxt->pw = PRIVSEP(getpwnamallow(user))) != NULL) authctxt->valid = 1; else { debug("do_authentication: invalid user %s", user); authctxt->pw = fakepw(); + BLACKLIST_NOTIFY(BLACKLIST_AUTH_FAIL); } /* Configuration may have changed as a result of Match */ if (options.num_auth_methods != 0) fatal("AuthenticationMethods is not supported with SSH " "protocol 1"); setproctitle("%s%s", authctxt->valid ? user : "unknown", use_privsep ? " [net]" : ""); #ifdef USE_PAM if (options.use_pam) PRIVSEP(start_pam(authctxt)); #endif /* * If we are not running as root, the user must have the same uid as * the server. */ #ifndef HAVE_CYGWIN if (!use_privsep && getuid() != 0 && authctxt->pw && authctxt->pw->pw_uid != getuid()) packet_disconnect("Cannot change user when server not running as root."); #endif /* * Loop until the user has been authenticated or the connection is * closed, do_authloop() returns only if authentication is successful */ do_authloop(authctxt); /* The user has been authenticated and accepted. */ packet_start(SSH_SMSG_SUCCESS); packet_send(); packet_write_wait(); } #endif /* WITH_SSH1 */ diff --git a/crypto/openssh/auth2.c b/crypto/openssh/auth2.c index 1d9aab037dd6..ee3c5dd87ce1 100644 --- a/crypto/openssh/auth2.c +++ b/crypto/openssh/auth2.c @@ -1,649 +1,651 @@ /* $OpenBSD: auth2.c,v 1.135 2015/01/19 20:07:45 markus Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "includes.h" __RCSID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include "atomicio.h" #include "xmalloc.h" #include "ssh2.h" #include "packet.h" #include "log.h" #include "buffer.h" #include "misc.h" #include "servconf.h" #include "compat.h" #include "key.h" #include "hostfile.h" #include "auth.h" #include "dispatch.h" #include "pathnames.h" #include "buffer.h" #include "canohost.h" +#include "blacklist_client.h" #ifdef GSSAPI #include "ssh-gss.h" #endif #include "monitor_wrap.h" /* import */ extern ServerOptions options; extern u_char *session_id2; extern u_int session_id2_len; extern Buffer loginmsg; /* methods */ extern Authmethod method_none; extern Authmethod method_pubkey; extern Authmethod method_passwd; extern Authmethod method_kbdint; extern Authmethod method_hostbased; #ifdef GSSAPI extern Authmethod method_gssapi; #endif Authmethod *authmethods[] = { &method_none, &method_pubkey, #ifdef GSSAPI &method_gssapi, #endif &method_passwd, &method_kbdint, &method_hostbased, NULL }; /* protocol */ static int input_service_request(int, u_int32_t, void *); static int input_userauth_request(int, u_int32_t, void *); /* helper */ static Authmethod *authmethod_lookup(Authctxt *, const char *); static char *authmethods_get(Authctxt *authctxt); #define MATCH_NONE 0 /* method or submethod mismatch */ #define MATCH_METHOD 1 /* method matches (no submethod specified) */ #define MATCH_BOTH 2 /* method and submethod match */ #define MATCH_PARTIAL 3 /* method matches, submethod can't be checked */ static int list_starts_with(const char *, const char *, const char *); char * auth2_read_banner(void) { struct stat st; char *banner = NULL; size_t len, n; int fd; if ((fd = open(options.banner, O_RDONLY)) == -1) return (NULL); if (fstat(fd, &st) == -1) { close(fd); return (NULL); } if (st.st_size <= 0 || st.st_size > 1*1024*1024) { close(fd); return (NULL); } len = (size_t)st.st_size; /* truncate */ banner = xmalloc(len + 1); n = atomicio(read, fd, banner, len); close(fd); if (n != len) { free(banner); return (NULL); } banner[n] = '\0'; return (banner); } void userauth_send_banner(const char *msg) { if (datafellows & SSH_BUG_BANNER) return; packet_start(SSH2_MSG_USERAUTH_BANNER); packet_put_cstring(msg); packet_put_cstring(""); /* language, unused */ packet_send(); debug("%s: sent", __func__); } static void userauth_banner(void) { char *banner = NULL; if (options.banner == NULL || (datafellows & SSH_BUG_BANNER) != 0) return; if ((banner = PRIVSEP(auth2_read_banner())) == NULL) goto done; userauth_send_banner(banner); done: free(banner); } /* * loop until authctxt->success == TRUE */ void do_authentication2(Authctxt *authctxt) { dispatch_init(&dispatch_protocol_error); dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request); dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt); } /*ARGSUSED*/ static int input_service_request(int type, u_int32_t seq, void *ctxt) { Authctxt *authctxt = ctxt; u_int len; int acceptit = 0; char *service = packet_get_cstring(&len); packet_check_eom(); if (authctxt == NULL) fatal("input_service_request: no authctxt"); if (strcmp(service, "ssh-userauth") == 0) { if (!authctxt->success) { acceptit = 1; /* now we can handle user-auth requests */ dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request); } } /* XXX all other service requests are denied */ if (acceptit) { packet_start(SSH2_MSG_SERVICE_ACCEPT); packet_put_cstring(service); packet_send(); packet_write_wait(); } else { debug("bad service request %s", service); packet_disconnect("bad service request %s", service); } free(service); return 0; } /*ARGSUSED*/ static int input_userauth_request(int type, u_int32_t seq, void *ctxt) { Authctxt *authctxt = ctxt; Authmethod *m = NULL; char *user, *service, *method, *style = NULL; int authenticated = 0; #ifdef HAVE_LOGIN_CAP login_cap_t *lc; const char *from_host, *from_ip; from_host = get_canonical_hostname(options.use_dns); from_ip = get_remote_ipaddr(); #endif if (authctxt == NULL) fatal("input_userauth_request: no authctxt"); user = packet_get_cstring(NULL); service = packet_get_cstring(NULL); method = packet_get_cstring(NULL); debug("userauth-request for user %s service %s method %s", user, service, method); debug("attempt %d failures %d", authctxt->attempt, authctxt->failures); if ((style = strchr(user, ':')) != NULL) *style++ = 0; if (authctxt->attempt++ == 0) { /* setup auth context */ authctxt->pw = PRIVSEP(getpwnamallow(user)); authctxt->user = xstrdup(user); if (authctxt->pw && strcmp(service, "ssh-connection")==0) { authctxt->valid = 1; debug2("input_userauth_request: setting up authctxt for %s", user); } else { logit("input_userauth_request: invalid user %s", user); authctxt->pw = fakepw(); + BLACKLIST_NOTIFY(BLACKLIST_AUTH_FAIL); #ifdef SSH_AUDIT_EVENTS PRIVSEP(audit_event(SSH_INVALID_USER)); #endif } #ifdef USE_PAM if (options.use_pam) PRIVSEP(start_pam(authctxt)); #endif setproctitle("%s%s", authctxt->valid ? user : "unknown", use_privsep ? " [net]" : ""); authctxt->service = xstrdup(service); authctxt->style = style ? xstrdup(style) : NULL; if (use_privsep) mm_inform_authserv(service, style); userauth_banner(); if (auth2_setup_methods_lists(authctxt) != 0) packet_disconnect("no authentication methods enabled"); } else if (strcmp(user, authctxt->user) != 0 || strcmp(service, authctxt->service) != 0) { packet_disconnect("Change of username or service not allowed: " "(%s,%s) -> (%s,%s)", authctxt->user, authctxt->service, user, service); } #ifdef HAVE_LOGIN_CAP if (authctxt->pw != NULL) { lc = login_getpwclass(authctxt->pw); if (lc == NULL) lc = login_getclassbyname(NULL, authctxt->pw); if (!auth_hostok(lc, from_host, from_ip)) { logit("Denied connection for %.200s from %.200s [%.200s].", authctxt->pw->pw_name, from_host, from_ip); packet_disconnect("Sorry, you are not allowed to connect."); } if (!auth_timeok(lc, time(NULL))) { logit("LOGIN %.200s REFUSED (TIME) FROM %.200s", authctxt->pw->pw_name, from_host); packet_disconnect("Logins not available right now."); } login_close(lc); lc = NULL; } #endif /* HAVE_LOGIN_CAP */ /* reset state */ auth2_challenge_stop(authctxt); #ifdef GSSAPI /* XXX move to auth2_gssapi_stop() */ dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL); #endif authctxt->postponed = 0; authctxt->server_caused_failure = 0; /* try to authenticate user */ m = authmethod_lookup(authctxt, method); if (m != NULL && authctxt->failures < options.max_authtries) { debug2("input_userauth_request: try method %s", method); authenticated = m->userauth(authctxt); } userauth_finish(authctxt, authenticated, method, NULL); free(service); free(user); free(method); return 0; } void userauth_finish(Authctxt *authctxt, int authenticated, const char *method, const char *submethod) { char *methods; int partial = 0; if (!authctxt->valid && authenticated) fatal("INTERNAL ERROR: authenticated invalid user %s", authctxt->user); if (authenticated && authctxt->postponed) fatal("INTERNAL ERROR: authenticated and postponed"); /* Special handling for root */ if (authenticated && authctxt->pw->pw_uid == 0 && !auth_root_allowed(method)) { authenticated = 0; #ifdef SSH_AUDIT_EVENTS PRIVSEP(audit_event(SSH_LOGIN_ROOT_DENIED)); #endif } if (authenticated && options.num_auth_methods != 0) { if (!auth2_update_methods_lists(authctxt, method, submethod)) { authenticated = 0; partial = 1; } } /* Log before sending the reply */ auth_log(authctxt, authenticated, partial, method, submethod); if (authctxt->postponed) return; #ifdef USE_PAM if (options.use_pam && authenticated) { if (!PRIVSEP(do_pam_account())) { /* if PAM returned a message, send it to the user */ if (buffer_len(&loginmsg) > 0) { buffer_append(&loginmsg, "\0", 1); userauth_send_banner(buffer_ptr(&loginmsg)); packet_write_wait(); } fatal("Access denied for user %s by PAM account " "configuration", authctxt->user); } } #endif #ifdef _UNICOS if (authenticated && cray_access_denied(authctxt->user)) { authenticated = 0; fatal("Access denied for user %s.", authctxt->user); } #endif /* _UNICOS */ if (authenticated == 1) { /* turn off userauth */ dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &dispatch_protocol_ignore); packet_start(SSH2_MSG_USERAUTH_SUCCESS); packet_send(); packet_write_wait(); /* now we can break out */ authctxt->success = 1; } else { /* Allow initial try of "none" auth without failure penalty */ if (!partial && !authctxt->server_caused_failure && (authctxt->attempt > 1 || strcmp(method, "none") != 0)) authctxt->failures++; if (authctxt->failures >= options.max_authtries) { #ifdef SSH_AUDIT_EVENTS PRIVSEP(audit_event(SSH_LOGIN_EXCEED_MAXTRIES)); #endif auth_maxtries_exceeded(authctxt); } methods = authmethods_get(authctxt); debug3("%s: failure partial=%d next methods=\"%s\"", __func__, partial, methods); packet_start(SSH2_MSG_USERAUTH_FAILURE); packet_put_cstring(methods); packet_put_char(partial); packet_send(); packet_write_wait(); free(methods); } } /* * Checks whether method is allowed by at least one AuthenticationMethods * methods list. Returns 1 if allowed, or no methods lists configured. * 0 otherwise. */ int auth2_method_allowed(Authctxt *authctxt, const char *method, const char *submethod) { u_int i; /* * NB. authctxt->num_auth_methods might be zero as a result of * auth2_setup_methods_lists(), so check the configuration. */ if (options.num_auth_methods == 0) return 1; for (i = 0; i < authctxt->num_auth_methods; i++) { if (list_starts_with(authctxt->auth_methods[i], method, submethod) != MATCH_NONE) return 1; } return 0; } static char * authmethods_get(Authctxt *authctxt) { Buffer b; char *list; u_int i; buffer_init(&b); for (i = 0; authmethods[i] != NULL; i++) { if (strcmp(authmethods[i]->name, "none") == 0) continue; if (authmethods[i]->enabled == NULL || *(authmethods[i]->enabled) == 0) continue; if (!auth2_method_allowed(authctxt, authmethods[i]->name, NULL)) continue; if (buffer_len(&b) > 0) buffer_append(&b, ",", 1); buffer_append(&b, authmethods[i]->name, strlen(authmethods[i]->name)); } buffer_append(&b, "\0", 1); list = xstrdup(buffer_ptr(&b)); buffer_free(&b); return list; } static Authmethod * authmethod_lookup(Authctxt *authctxt, const char *name) { int i; if (name != NULL) for (i = 0; authmethods[i] != NULL; i++) if (authmethods[i]->enabled != NULL && *(authmethods[i]->enabled) != 0 && strcmp(name, authmethods[i]->name) == 0 && auth2_method_allowed(authctxt, authmethods[i]->name, NULL)) return authmethods[i]; debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); return NULL; } /* * Check a comma-separated list of methods for validity. Is need_enable is * non-zero, then also require that the methods are enabled. * Returns 0 on success or -1 if the methods list is invalid. */ int auth2_methods_valid(const char *_methods, int need_enable) { char *methods, *omethods, *method, *p; u_int i, found; int ret = -1; if (*_methods == '\0') { error("empty authentication method list"); return -1; } omethods = methods = xstrdup(_methods); while ((method = strsep(&methods, ",")) != NULL) { for (found = i = 0; !found && authmethods[i] != NULL; i++) { if ((p = strchr(method, ':')) != NULL) *p = '\0'; if (strcmp(method, authmethods[i]->name) != 0) continue; if (need_enable) { if (authmethods[i]->enabled == NULL || *(authmethods[i]->enabled) == 0) { error("Disabled method \"%s\" in " "AuthenticationMethods list \"%s\"", method, _methods); goto out; } } found = 1; break; } if (!found) { error("Unknown authentication method \"%s\" in list", method); goto out; } } ret = 0; out: free(omethods); return ret; } /* * Prune the AuthenticationMethods supplied in the configuration, removing * any methods lists that include disabled methods. Note that this might * leave authctxt->num_auth_methods == 0, even when multiple required auth * has been requested. For this reason, all tests for whether multiple is * enabled should consult options.num_auth_methods directly. */ int auth2_setup_methods_lists(Authctxt *authctxt) { u_int i; if (options.num_auth_methods == 0) return 0; debug3("%s: checking methods", __func__); authctxt->auth_methods = xcalloc(options.num_auth_methods, sizeof(*authctxt->auth_methods)); authctxt->num_auth_methods = 0; for (i = 0; i < options.num_auth_methods; i++) { if (auth2_methods_valid(options.auth_methods[i], 1) != 0) { logit("Authentication methods list \"%s\" contains " "disabled method, skipping", options.auth_methods[i]); continue; } debug("authentication methods list %d: %s", authctxt->num_auth_methods, options.auth_methods[i]); authctxt->auth_methods[authctxt->num_auth_methods++] = xstrdup(options.auth_methods[i]); } if (authctxt->num_auth_methods == 0) { error("No AuthenticationMethods left after eliminating " "disabled methods"); return -1; } return 0; } static int list_starts_with(const char *methods, const char *method, const char *submethod) { size_t l = strlen(method); int match; const char *p; if (strncmp(methods, method, l) != 0) return MATCH_NONE; p = methods + l; match = MATCH_METHOD; if (*p == ':') { if (!submethod) return MATCH_PARTIAL; l = strlen(submethod); p += 1; if (strncmp(submethod, p, l)) return MATCH_NONE; p += l; match = MATCH_BOTH; } if (*p != ',' && *p != '\0') return MATCH_NONE; return match; } /* * Remove method from the start of a comma-separated list of methods. * Returns 0 if the list of methods did not start with that method or 1 * if it did. */ static int remove_method(char **methods, const char *method, const char *submethod) { char *omethods = *methods, *p; size_t l = strlen(method); int match; match = list_starts_with(omethods, method, submethod); if (match != MATCH_METHOD && match != MATCH_BOTH) return 0; p = omethods + l; if (submethod && match == MATCH_BOTH) p += 1 + strlen(submethod); /* include colon */ if (*p == ',') p++; *methods = xstrdup(p); free(omethods); return 1; } /* * Called after successful authentication. Will remove the successful method * from the start of each list in which it occurs. If it was the last method * in any list, then authentication is deemed successful. * Returns 1 if the method completed any authentication list or 0 otherwise. */ int auth2_update_methods_lists(Authctxt *authctxt, const char *method, const char *submethod) { u_int i, found = 0; debug3("%s: updating methods list after \"%s\"", __func__, method); for (i = 0; i < authctxt->num_auth_methods; i++) { if (!remove_method(&(authctxt->auth_methods[i]), method, submethod)) continue; found = 1; if (*authctxt->auth_methods[i] == '\0') { debug2("authentication methods list %d complete", i); return 1; } debug3("authentication methods list %d remaining: \"%s\"", i, authctxt->auth_methods[i]); } /* This should not happen, but would be bad if it did */ if (!found) fatal("%s: method not in AuthenticationMethods", __func__); return 0; } diff --git a/crypto/openssh/blacklist.c b/crypto/openssh/blacklist.c new file mode 100644 index 000000000000..4c9d91dec164 --- /dev/null +++ b/crypto/openssh/blacklist.c @@ -0,0 +1,97 @@ +/*- + * Copyright (c) 2015 The NetBSD Foundation, Inc. + * Copyright (c) 2016 The FreeBSD Foundation, Inc. + * All rights reserved. + * + * Portions of this software were developed by Kurt Lidl + * under sponsorship from the FreeBSD Foundation. + * + * This code is derived from software contributed to The NetBSD Foundation + * by Christos Zoulas. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED + * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS + * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" + +#include +#include +#include +#include +#include +#include +#include + +#include "ssh.h" +#include "packet.h" +#include "log.h" +#include "misc.h" +#include "servconf.h" +#include "blacklist_client.h" +#include + +static struct blacklist *blstate = NULL; + +/* import */ +extern ServerOptions options; + +/* internal definition from bl.h */ +struct blacklist *bl_create(bool, char *, void (*)(int, const char *, va_list)); + +/* impedence match vsyslog() to sshd's internal logging levels */ +void +im_log(int priority, const char *message, va_list args) +{ + LogLevel imlevel; + + switch (priority) { + case LOG_ERR: + imlevel = SYSLOG_LEVEL_ERROR; + break; + case LOG_DEBUG: + imlevel = SYSLOG_LEVEL_DEBUG1; + break; + case LOG_INFO: + imlevel = SYSLOG_LEVEL_INFO; + break; + default: + imlevel = SYSLOG_LEVEL_DEBUG2; + } + do_log(imlevel, message, args); +} + +void +blacklist_init(void) +{ + + if (options.use_blacklist) + blstate = bl_create(false, NULL, im_log); +} + +void +blacklist_notify(int action) +{ + + if (blstate != NULL && packet_connection_is_on_socket()) + (void)blacklist_r(blstate, action, + packet_get_connection_in(), "ssh"); +} diff --git a/crypto/openssh/blacklist_client.h b/crypto/openssh/blacklist_client.h new file mode 100644 index 000000000000..9479bb27be46 --- /dev/null +++ b/crypto/openssh/blacklist_client.h @@ -0,0 +1,57 @@ +/*- + * Copyright (c) 2015 The NetBSD Foundation, Inc. + * Copyright (c) 2016 The FreeBSD Foundation, Inc. + * All rights reserved. + * + * Portions of this software were developed by Kurt Lidl + * under sponsorship from the FreeBSD Foundation. + * + * This code is derived from software contributed to The NetBSD Foundation + * by Christos Zoulas. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED + * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS + * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef BLACKLIST_CLIENT_H +#define BLACKLIST_CLIENT_H + +enum { + BLACKLIST_AUTH_OK = 0, + BLACKLIST_AUTH_FAIL +}; + +#ifdef USE_BLACKLIST +void blacklist_init(void); +void blacklist_notify(int); + +#define BLACKLIST_INIT() blacklist_init() +#define BLACKLIST_NOTIFY(x) blacklist_notify(x) + +#else + +#define BLACKLIST_INIT() +#define BLACKLIST_NOTIFY(x) + +#endif + + +#endif /* BLACKLIST_CLIENT_H */ diff --git a/crypto/openssh/packet.c b/crypto/openssh/packet.c index f3b3ce9cf250..be4b4b6e22d9 100644 --- a/crypto/openssh/packet.c +++ b/crypto/openssh/packet.c @@ -1,2975 +1,2977 @@ /* $OpenBSD: packet.c,v 1.229 2016/02/17 22:20:14 djm Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved * This file contains code implementing the packet protocol and communication * with the other side. This same code is used both on client and server side. * * As far as I am concerned, the code I have written for this software * can be used freely for any purpose. Any derived versions of this * software must be clearly marked as such, and if the derived work is * incompatible with the protocol description in the RFC file, it must be * called by a name other than "ssh" or "Secure Shell". * * * SSH2 packet format added by Markus Friedl. * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "includes.h" __RCSID("$FreeBSD$"); #include /* MIN roundup */ #include #include "openbsd-compat/sys-queue.h" #include #ifdef HAVE_SYS_TIME_H # include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include "buffer.h" /* typedefs XXX */ #include "key.h" /* typedefs XXX */ #include "xmalloc.h" #include "crc32.h" #include "deattack.h" #include "compat.h" #include "ssh1.h" #include "ssh2.h" #include "cipher.h" #include "sshkey.h" #include "kex.h" #include "digest.h" #include "mac.h" #include "log.h" #include "canohost.h" #include "misc.h" #include "channels.h" #include "ssh.h" #include "packet.h" #include "ssherr.h" #include "sshbuf.h" +#include "blacklist_client.h" #ifdef PACKET_DEBUG #define DBG(x) x #else #define DBG(x) #endif #define PACKET_MAX_SIZE (256 * 1024) struct packet_state { u_int32_t seqnr; u_int32_t packets; u_int64_t blocks; u_int64_t bytes; }; struct packet { TAILQ_ENTRY(packet) next; u_char type; struct sshbuf *payload; }; struct session_state { /* * This variable contains the file descriptors used for * communicating with the other side. connection_in is used for * reading; connection_out for writing. These can be the same * descriptor, in which case it is assumed to be a socket. */ int connection_in; int connection_out; /* Protocol flags for the remote side. */ u_int remote_protocol_flags; /* Encryption context for receiving data. Only used for decryption. */ struct sshcipher_ctx receive_context; /* Encryption context for sending data. Only used for encryption. */ struct sshcipher_ctx send_context; /* Buffer for raw input data from the socket. */ struct sshbuf *input; /* Buffer for raw output data going to the socket. */ struct sshbuf *output; /* Buffer for the partial outgoing packet being constructed. */ struct sshbuf *outgoing_packet; /* Buffer for the incoming packet currently being processed. */ struct sshbuf *incoming_packet; /* Scratch buffer for packet compression/decompression. */ struct sshbuf *compression_buffer; /* Incoming/outgoing compression dictionaries */ z_stream compression_in_stream; z_stream compression_out_stream; int compression_in_started; int compression_out_started; int compression_in_failures; int compression_out_failures; /* * Flag indicating whether packet compression/decompression is * enabled. */ int packet_compression; /* default maximum packet size */ u_int max_packet_size; /* Flag indicating whether this module has been initialized. */ int initialized; /* Set to true if the connection is interactive. */ int interactive_mode; /* Set to true if we are the server side. */ int server_side; /* Set to true if we are authenticated. */ int after_authentication; int keep_alive_timeouts; /* The maximum time that we will wait to send or receive a packet */ int packet_timeout_ms; /* Session key information for Encryption and MAC */ struct newkeys *newkeys[MODE_MAX]; struct packet_state p_read, p_send; /* Volume-based rekeying */ u_int64_t max_blocks_in, max_blocks_out, rekey_limit; /* Time-based rekeying */ u_int32_t rekey_interval; /* how often in seconds */ time_t rekey_time; /* time of last rekeying */ /* Session key for protocol v1 */ u_char ssh1_key[SSH_SESSION_KEY_LENGTH]; u_int ssh1_keylen; /* roundup current message to extra_pad bytes */ u_char extra_pad; /* XXX discard incoming data after MAC error */ u_int packet_discard; struct sshmac *packet_discard_mac; /* Used in packet_read_poll2() */ u_int packlen; /* Used in packet_send2 */ int rekeying; /* Used in packet_set_interactive */ int set_interactive_called; /* Used in packet_set_maxsize */ int set_maxsize_called; /* One-off warning about weak ciphers */ int cipher_warning_done; /* SSH1 CRC compensation attack detector */ struct deattack_ctx deattack; TAILQ_HEAD(, packet) outgoing; }; struct ssh * ssh_alloc_session_state(void) { struct ssh *ssh = NULL; struct session_state *state = NULL; if ((ssh = calloc(1, sizeof(*ssh))) == NULL || (state = calloc(1, sizeof(*state))) == NULL || (state->input = sshbuf_new()) == NULL || (state->output = sshbuf_new()) == NULL || (state->outgoing_packet = sshbuf_new()) == NULL || (state->incoming_packet = sshbuf_new()) == NULL) goto fail; TAILQ_INIT(&state->outgoing); TAILQ_INIT(&ssh->private_keys); TAILQ_INIT(&ssh->public_keys); state->connection_in = -1; state->connection_out = -1; state->max_packet_size = 32768; state->packet_timeout_ms = -1; state->p_send.packets = state->p_read.packets = 0; state->initialized = 1; /* * ssh_packet_send2() needs to queue packets until * we've done the initial key exchange. */ state->rekeying = 1; ssh->state = state; return ssh; fail: if (state) { sshbuf_free(state->input); sshbuf_free(state->output); sshbuf_free(state->incoming_packet); sshbuf_free(state->outgoing_packet); free(state); } free(ssh); return NULL; } /* Returns nonzero if rekeying is in progress */ int ssh_packet_is_rekeying(struct ssh *ssh) { return compat20 && (ssh->state->rekeying || (ssh->kex != NULL && ssh->kex->done == 0)); } /* * Sets the descriptors used for communication. Disables encryption until * packet_set_encryption_key is called. */ struct ssh * ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out) { struct session_state *state; const struct sshcipher *none = cipher_by_name("none"); int r; if (none == NULL) { error("%s: cannot load cipher 'none'", __func__); return NULL; } if (ssh == NULL) ssh = ssh_alloc_session_state(); if (ssh == NULL) { error("%s: cound not allocate state", __func__); return NULL; } state = ssh->state; state->connection_in = fd_in; state->connection_out = fd_out; if ((r = cipher_init(&state->send_context, none, (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 || (r = cipher_init(&state->receive_context, none, (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) { error("%s: cipher_init failed: %s", __func__, ssh_err(r)); free(ssh); return NULL; } state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL; deattack_init(&state->deattack); /* * Cache the IP address of the remote connection for use in error * messages that might be generated after the connection has closed. */ (void)ssh_remote_ipaddr(ssh); return ssh; } void ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count) { struct session_state *state = ssh->state; if (timeout <= 0 || count <= 0) { state->packet_timeout_ms = -1; return; } if ((INT_MAX / 1000) / count < timeout) state->packet_timeout_ms = INT_MAX; else state->packet_timeout_ms = timeout * count * 1000; } int ssh_packet_stop_discard(struct ssh *ssh) { struct session_state *state = ssh->state; int r; if (state->packet_discard_mac) { char buf[1024]; memset(buf, 'a', sizeof(buf)); while (sshbuf_len(state->incoming_packet) < PACKET_MAX_SIZE) if ((r = sshbuf_put(state->incoming_packet, buf, sizeof(buf))) != 0) return r; (void) mac_compute(state->packet_discard_mac, state->p_read.seqnr, sshbuf_ptr(state->incoming_packet), PACKET_MAX_SIZE, NULL, 0); } logit("Finished discarding for %.200s port %d", ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); return SSH_ERR_MAC_INVALID; } static int ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc, struct sshmac *mac, u_int packet_length, u_int discard) { struct session_state *state = ssh->state; int r; if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) { if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0) return r; return SSH_ERR_MAC_INVALID; } if (packet_length != PACKET_MAX_SIZE && mac && mac->enabled) state->packet_discard_mac = mac; if (sshbuf_len(state->input) >= discard && (r = ssh_packet_stop_discard(ssh)) != 0) return r; state->packet_discard = discard - sshbuf_len(state->input); return 0; } /* Returns 1 if remote host is connected via socket, 0 if not. */ int ssh_packet_connection_is_on_socket(struct ssh *ssh) { struct session_state *state = ssh->state; struct sockaddr_storage from, to; socklen_t fromlen, tolen; /* filedescriptors in and out are the same, so it's a socket */ if (state->connection_in == state->connection_out) return 1; fromlen = sizeof(from); memset(&from, 0, sizeof(from)); if (getpeername(state->connection_in, (struct sockaddr *)&from, &fromlen) < 0) return 0; tolen = sizeof(to); memset(&to, 0, sizeof(to)); if (getpeername(state->connection_out, (struct sockaddr *)&to, &tolen) < 0) return 0; if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0) return 0; if (from.ss_family != AF_INET && from.ss_family != AF_INET6) return 0; return 1; } void ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes) { if (ibytes) *ibytes = ssh->state->p_read.bytes; if (obytes) *obytes = ssh->state->p_send.bytes; } int ssh_packet_connection_af(struct ssh *ssh) { struct sockaddr_storage to; socklen_t tolen = sizeof(to); memset(&to, 0, sizeof(to)); if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to, &tolen) < 0) return 0; #ifdef IPV4_IN_IPV6 if (to.ss_family == AF_INET6 && IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr)) return AF_INET; #endif return to.ss_family; } /* Sets the connection into non-blocking mode. */ void ssh_packet_set_nonblocking(struct ssh *ssh) { /* Set the socket into non-blocking mode. */ set_nonblock(ssh->state->connection_in); if (ssh->state->connection_out != ssh->state->connection_in) set_nonblock(ssh->state->connection_out); } /* Returns the socket used for reading. */ int ssh_packet_get_connection_in(struct ssh *ssh) { return ssh->state->connection_in; } /* Returns the descriptor used for writing. */ int ssh_packet_get_connection_out(struct ssh *ssh) { return ssh->state->connection_out; } /* * Returns the IP-address of the remote host as a string. The returned * string must not be freed. */ const char * ssh_remote_ipaddr(struct ssh *ssh) { const int sock = ssh->state->connection_in; /* Check whether we have cached the ipaddr. */ if (ssh->remote_ipaddr == NULL) { if (ssh_packet_connection_is_on_socket(ssh)) { ssh->remote_ipaddr = get_peer_ipaddr(sock); ssh->remote_port = get_sock_port(sock, 0); } else { ssh->remote_ipaddr = strdup("UNKNOWN"); ssh->remote_port = 0; } } return ssh->remote_ipaddr; } /* Returns the port number of the remote host. */ int ssh_remote_port(struct ssh *ssh) { (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */ return ssh->remote_port; } /* Closes the connection and clears and frees internal data structures. */ void ssh_packet_close(struct ssh *ssh) { struct session_state *state = ssh->state; int r; u_int mode; if (!state->initialized) return; state->initialized = 0; if (state->connection_in == state->connection_out) { shutdown(state->connection_out, SHUT_RDWR); close(state->connection_out); } else { close(state->connection_in); close(state->connection_out); } sshbuf_free(state->input); sshbuf_free(state->output); sshbuf_free(state->outgoing_packet); sshbuf_free(state->incoming_packet); for (mode = 0; mode < MODE_MAX; mode++) kex_free_newkeys(state->newkeys[mode]); if (state->compression_buffer) { sshbuf_free(state->compression_buffer); if (state->compression_out_started) { z_streamp stream = &state->compression_out_stream; debug("compress outgoing: " "raw data %llu, compressed %llu, factor %.2f", (unsigned long long)stream->total_in, (unsigned long long)stream->total_out, stream->total_in == 0 ? 0.0 : (double) stream->total_out / stream->total_in); if (state->compression_out_failures == 0) deflateEnd(stream); } if (state->compression_in_started) { z_streamp stream = &state->compression_out_stream; debug("compress incoming: " "raw data %llu, compressed %llu, factor %.2f", (unsigned long long)stream->total_out, (unsigned long long)stream->total_in, stream->total_out == 0 ? 0.0 : (double) stream->total_in / stream->total_out); if (state->compression_in_failures == 0) inflateEnd(stream); } } if ((r = cipher_cleanup(&state->send_context)) != 0) error("%s: cipher_cleanup failed: %s", __func__, ssh_err(r)); if ((r = cipher_cleanup(&state->receive_context)) != 0) error("%s: cipher_cleanup failed: %s", __func__, ssh_err(r)); free(ssh->remote_ipaddr); ssh->remote_ipaddr = NULL; free(ssh->state); ssh->state = NULL; } /* Sets remote side protocol flags. */ void ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags) { ssh->state->remote_protocol_flags = protocol_flags; } /* Returns the remote protocol flags set earlier by the above function. */ u_int ssh_packet_get_protocol_flags(struct ssh *ssh) { return ssh->state->remote_protocol_flags; } /* * Starts packet compression from the next packet on in both directions. * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip. */ static int ssh_packet_init_compression(struct ssh *ssh) { if (!ssh->state->compression_buffer && ((ssh->state->compression_buffer = sshbuf_new()) == NULL)) return SSH_ERR_ALLOC_FAIL; return 0; } static int start_compression_out(struct ssh *ssh, int level) { if (level < 1 || level > 9) return SSH_ERR_INVALID_ARGUMENT; debug("Enabling compression at level %d.", level); if (ssh->state->compression_out_started == 1) deflateEnd(&ssh->state->compression_out_stream); switch (deflateInit(&ssh->state->compression_out_stream, level)) { case Z_OK: ssh->state->compression_out_started = 1; break; case Z_MEM_ERROR: return SSH_ERR_ALLOC_FAIL; default: return SSH_ERR_INTERNAL_ERROR; } return 0; } static int start_compression_in(struct ssh *ssh) { if (ssh->state->compression_in_started == 1) inflateEnd(&ssh->state->compression_in_stream); switch (inflateInit(&ssh->state->compression_in_stream)) { case Z_OK: ssh->state->compression_in_started = 1; break; case Z_MEM_ERROR: return SSH_ERR_ALLOC_FAIL; default: return SSH_ERR_INTERNAL_ERROR; } return 0; } int ssh_packet_start_compression(struct ssh *ssh, int level) { int r; if (ssh->state->packet_compression && !compat20) return SSH_ERR_INTERNAL_ERROR; ssh->state->packet_compression = 1; if ((r = ssh_packet_init_compression(ssh)) != 0 || (r = start_compression_in(ssh)) != 0 || (r = start_compression_out(ssh, level)) != 0) return r; return 0; } /* XXX remove need for separate compression buffer */ static int compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out) { u_char buf[4096]; int r, status; if (ssh->state->compression_out_started != 1) return SSH_ERR_INTERNAL_ERROR; /* This case is not handled below. */ if (sshbuf_len(in) == 0) return 0; /* Input is the contents of the input buffer. */ if ((ssh->state->compression_out_stream.next_in = sshbuf_mutable_ptr(in)) == NULL) return SSH_ERR_INTERNAL_ERROR; ssh->state->compression_out_stream.avail_in = sshbuf_len(in); /* Loop compressing until deflate() returns with avail_out != 0. */ do { /* Set up fixed-size output buffer. */ ssh->state->compression_out_stream.next_out = buf; ssh->state->compression_out_stream.avail_out = sizeof(buf); /* Compress as much data into the buffer as possible. */ status = deflate(&ssh->state->compression_out_stream, Z_PARTIAL_FLUSH); switch (status) { case Z_MEM_ERROR: return SSH_ERR_ALLOC_FAIL; case Z_OK: /* Append compressed data to output_buffer. */ if ((r = sshbuf_put(out, buf, sizeof(buf) - ssh->state->compression_out_stream.avail_out)) != 0) return r; break; case Z_STREAM_ERROR: default: ssh->state->compression_out_failures++; return SSH_ERR_INVALID_FORMAT; } } while (ssh->state->compression_out_stream.avail_out == 0); return 0; } static int uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out) { u_char buf[4096]; int r, status; if (ssh->state->compression_in_started != 1) return SSH_ERR_INTERNAL_ERROR; if ((ssh->state->compression_in_stream.next_in = sshbuf_mutable_ptr(in)) == NULL) return SSH_ERR_INTERNAL_ERROR; ssh->state->compression_in_stream.avail_in = sshbuf_len(in); for (;;) { /* Set up fixed-size output buffer. */ ssh->state->compression_in_stream.next_out = buf; ssh->state->compression_in_stream.avail_out = sizeof(buf); status = inflate(&ssh->state->compression_in_stream, Z_PARTIAL_FLUSH); switch (status) { case Z_OK: if ((r = sshbuf_put(out, buf, sizeof(buf) - ssh->state->compression_in_stream.avail_out)) != 0) return r; break; case Z_BUF_ERROR: /* * Comments in zlib.h say that we should keep calling * inflate() until we get an error. This appears to * be the error that we get. */ return 0; case Z_DATA_ERROR: return SSH_ERR_INVALID_FORMAT; case Z_MEM_ERROR: return SSH_ERR_ALLOC_FAIL; case Z_STREAM_ERROR: default: ssh->state->compression_in_failures++; return SSH_ERR_INTERNAL_ERROR; } } /* NOTREACHED */ } /* Serialise compression state into a blob for privsep */ static int ssh_packet_get_compress_state(struct sshbuf *m, struct ssh *ssh) { struct session_state *state = ssh->state; struct sshbuf *b; int r; if ((b = sshbuf_new()) == NULL) return SSH_ERR_ALLOC_FAIL; if (state->compression_in_started) { if ((r = sshbuf_put_string(b, &state->compression_in_stream, sizeof(state->compression_in_stream))) != 0) goto out; } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0) goto out; if (state->compression_out_started) { if ((r = sshbuf_put_string(b, &state->compression_out_stream, sizeof(state->compression_out_stream))) != 0) goto out; } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0) goto out; r = sshbuf_put_stringb(m, b); out: sshbuf_free(b); return r; } /* Deserialise compression state from a blob for privsep */ static int ssh_packet_set_compress_state(struct ssh *ssh, struct sshbuf *m) { struct session_state *state = ssh->state; struct sshbuf *b = NULL; int r; const u_char *inblob, *outblob; size_t inl, outl; if ((r = sshbuf_froms(m, &b)) != 0) goto out; if ((r = sshbuf_get_string_direct(b, &inblob, &inl)) != 0 || (r = sshbuf_get_string_direct(b, &outblob, &outl)) != 0) goto out; if (inl == 0) state->compression_in_started = 0; else if (inl != sizeof(state->compression_in_stream)) { r = SSH_ERR_INTERNAL_ERROR; goto out; } else { state->compression_in_started = 1; memcpy(&state->compression_in_stream, inblob, inl); } if (outl == 0) state->compression_out_started = 0; else if (outl != sizeof(state->compression_out_stream)) { r = SSH_ERR_INTERNAL_ERROR; goto out; } else { state->compression_out_started = 1; memcpy(&state->compression_out_stream, outblob, outl); } r = 0; out: sshbuf_free(b); return r; } void ssh_packet_set_compress_hooks(struct ssh *ssh, void *ctx, void *(*allocfunc)(void *, u_int, u_int), void (*freefunc)(void *, void *)) { ssh->state->compression_out_stream.zalloc = (alloc_func)allocfunc; ssh->state->compression_out_stream.zfree = (free_func)freefunc; ssh->state->compression_out_stream.opaque = ctx; ssh->state->compression_in_stream.zalloc = (alloc_func)allocfunc; ssh->state->compression_in_stream.zfree = (free_func)freefunc; ssh->state->compression_in_stream.opaque = ctx; } /* * Causes any further packets to be encrypted using the given key. The same * key is used for both sending and reception. However, both directions are * encrypted independently of each other. */ void ssh_packet_set_encryption_key(struct ssh *ssh, const u_char *key, u_int keylen, int number) { #ifndef WITH_SSH1 fatal("no SSH protocol 1 support"); #else /* WITH_SSH1 */ struct session_state *state = ssh->state; const struct sshcipher *cipher = cipher_by_number(number); int r; const char *wmsg; if (cipher == NULL) fatal("%s: unknown cipher number %d", __func__, number); if (keylen < 20) fatal("%s: keylen too small: %d", __func__, keylen); if (keylen > SSH_SESSION_KEY_LENGTH) fatal("%s: keylen too big: %d", __func__, keylen); memcpy(state->ssh1_key, key, keylen); state->ssh1_keylen = keylen; if ((r = cipher_init(&state->send_context, cipher, key, keylen, NULL, 0, CIPHER_ENCRYPT)) != 0 || (r = cipher_init(&state->receive_context, cipher, key, keylen, NULL, 0, CIPHER_DECRYPT) != 0)) fatal("%s: cipher_init failed: %s", __func__, ssh_err(r)); if (!state->cipher_warning_done && ((wmsg = cipher_warning_message(&state->send_context)) != NULL || (wmsg = cipher_warning_message(&state->send_context)) != NULL)) { error("Warning: %s", wmsg); state->cipher_warning_done = 1; } #endif /* WITH_SSH1 */ } /* * Finalizes and sends the packet. If the encryption key has been set, * encrypts the packet before sending. */ int ssh_packet_send1(struct ssh *ssh) { struct session_state *state = ssh->state; u_char buf[8], *cp; int r, padding, len; u_int checksum; /* * If using packet compression, compress the payload of the outgoing * packet. */ if (state->packet_compression) { sshbuf_reset(state->compression_buffer); /* Skip padding. */ if ((r = sshbuf_consume(state->outgoing_packet, 8)) != 0) goto out; /* padding */ if ((r = sshbuf_put(state->compression_buffer, "\0\0\0\0\0\0\0\0", 8)) != 0) goto out; if ((r = compress_buffer(ssh, state->outgoing_packet, state->compression_buffer)) != 0) goto out; sshbuf_reset(state->outgoing_packet); if ((r = sshbuf_putb(state->outgoing_packet, state->compression_buffer)) != 0) goto out; } /* Compute packet length without padding (add checksum, remove padding). */ len = sshbuf_len(state->outgoing_packet) + 4 - 8; /* Insert padding. Initialized to zero in packet_start1() */ padding = 8 - len % 8; if (!state->send_context.plaintext) { cp = sshbuf_mutable_ptr(state->outgoing_packet); if (cp == NULL) { r = SSH_ERR_INTERNAL_ERROR; goto out; } arc4random_buf(cp + 8 - padding, padding); } if ((r = sshbuf_consume(state->outgoing_packet, 8 - padding)) != 0) goto out; /* Add check bytes. */ checksum = ssh_crc32(sshbuf_ptr(state->outgoing_packet), sshbuf_len(state->outgoing_packet)); POKE_U32(buf, checksum); if ((r = sshbuf_put(state->outgoing_packet, buf, 4)) != 0) goto out; #ifdef PACKET_DEBUG fprintf(stderr, "packet_send plain: "); sshbuf_dump(state->outgoing_packet, stderr); #endif /* Append to output. */ POKE_U32(buf, len); if ((r = sshbuf_put(state->output, buf, 4)) != 0) goto out; if ((r = sshbuf_reserve(state->output, sshbuf_len(state->outgoing_packet), &cp)) != 0) goto out; if ((r = cipher_crypt(&state->send_context, 0, cp, sshbuf_ptr(state->outgoing_packet), sshbuf_len(state->outgoing_packet), 0, 0)) != 0) goto out; #ifdef PACKET_DEBUG fprintf(stderr, "encrypted: "); sshbuf_dump(state->output, stderr); #endif state->p_send.packets++; state->p_send.bytes += len + sshbuf_len(state->outgoing_packet); sshbuf_reset(state->outgoing_packet); /* * Note that the packet is now only buffered in output. It won't be * actually sent until ssh_packet_write_wait or ssh_packet_write_poll * is called. */ r = 0; out: return r; } int ssh_set_newkeys(struct ssh *ssh, int mode) { struct session_state *state = ssh->state; struct sshenc *enc; struct sshmac *mac; struct sshcomp *comp; struct sshcipher_ctx *cc; u_int64_t *max_blocks; const char *wmsg; int r, crypt_type; debug2("set_newkeys: mode %d", mode); if (mode == MODE_OUT) { cc = &state->send_context; crypt_type = CIPHER_ENCRYPT; state->p_send.packets = state->p_send.blocks = 0; max_blocks = &state->max_blocks_out; } else { cc = &state->receive_context; crypt_type = CIPHER_DECRYPT; state->p_read.packets = state->p_read.blocks = 0; max_blocks = &state->max_blocks_in; } if (state->newkeys[mode] != NULL) { debug("set_newkeys: rekeying, input %llu bytes %llu blocks, " "output %llu bytes %llu blocks", (unsigned long long)state->p_read.bytes, (unsigned long long)state->p_read.blocks, (unsigned long long)state->p_send.bytes, (unsigned long long)state->p_send.blocks); if ((r = cipher_cleanup(cc)) != 0) return r; enc = &state->newkeys[mode]->enc; mac = &state->newkeys[mode]->mac; comp = &state->newkeys[mode]->comp; mac_clear(mac); explicit_bzero(enc->iv, enc->iv_len); explicit_bzero(enc->key, enc->key_len); explicit_bzero(mac->key, mac->key_len); free(enc->name); free(enc->iv); free(enc->key); free(mac->name); free(mac->key); free(comp->name); free(state->newkeys[mode]); } /* move newkeys from kex to state */ if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL) return SSH_ERR_INTERNAL_ERROR; ssh->kex->newkeys[mode] = NULL; enc = &state->newkeys[mode]->enc; mac = &state->newkeys[mode]->mac; comp = &state->newkeys[mode]->comp; if (cipher_authlen(enc->cipher) == 0) { if ((r = mac_init(mac)) != 0) return r; } mac->enabled = 1; DBG(debug("cipher_init_context: %d", mode)); if ((r = cipher_init(cc, enc->cipher, enc->key, enc->key_len, enc->iv, enc->iv_len, crypt_type)) != 0) return r; if (!state->cipher_warning_done && (wmsg = cipher_warning_message(cc)) != NULL) { error("Warning: %s", wmsg); state->cipher_warning_done = 1; } /* Deleting the keys does not gain extra security */ /* explicit_bzero(enc->iv, enc->block_size); explicit_bzero(enc->key, enc->key_len); explicit_bzero(mac->key, mac->key_len); */ if ((comp->type == COMP_ZLIB || (comp->type == COMP_DELAYED && state->after_authentication)) && comp->enabled == 0) { if ((r = ssh_packet_init_compression(ssh)) < 0) return r; if (mode == MODE_OUT) { if ((r = start_compression_out(ssh, 6)) != 0) return r; } else { if ((r = start_compression_in(ssh)) != 0) return r; } comp->enabled = 1; } /* * The 2^(blocksize*2) limit is too expensive for 3DES, * blowfish, etc, so enforce a 1GB limit for small blocksizes. */ if (enc->block_size >= 16) *max_blocks = (u_int64_t)1 << (enc->block_size*2); else *max_blocks = ((u_int64_t)1 << 30) / enc->block_size; if (state->rekey_limit) *max_blocks = MIN(*max_blocks, state->rekey_limit / enc->block_size); debug("rekey after %llu blocks", (unsigned long long)*max_blocks); return 0; } #define MAX_PACKETS (1U<<31) static int ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len) { struct session_state *state = ssh->state; u_int32_t out_blocks; /* XXX client can't cope with rekeying pre-auth */ if (!state->after_authentication) return 0; /* Haven't keyed yet or KEX in progress. */ if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh)) return 0; /* Peer can't rekey */ if (ssh->compat & SSH_BUG_NOREKEY) return 0; /* * Permit one packet in or out per rekey - this allows us to * make progress when rekey limits are very small. */ if (state->p_send.packets == 0 && state->p_read.packets == 0) return 0; /* Time-based rekeying */ if (state->rekey_interval != 0 && state->rekey_time + state->rekey_interval <= monotime()) return 1; /* Always rekey when MAX_PACKETS sent in either direction */ if (state->p_send.packets > MAX_PACKETS || state->p_read.packets > MAX_PACKETS) return 1; /* Rekey after (cipher-specific) maxiumum blocks */ out_blocks = roundup(outbound_packet_len, state->newkeys[MODE_OUT]->enc.block_size); return (state->max_blocks_out && (state->p_send.blocks + out_blocks > state->max_blocks_out)) || (state->max_blocks_in && (state->p_read.blocks > state->max_blocks_in)); } /* * Delayed compression for SSH2 is enabled after authentication: * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent, * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received. */ static int ssh_packet_enable_delayed_compress(struct ssh *ssh) { struct session_state *state = ssh->state; struct sshcomp *comp = NULL; int r, mode; /* * Remember that we are past the authentication step, so rekeying * with COMP_DELAYED will turn on compression immediately. */ state->after_authentication = 1; for (mode = 0; mode < MODE_MAX; mode++) { /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */ if (state->newkeys[mode] == NULL) continue; comp = &state->newkeys[mode]->comp; if (comp && !comp->enabled && comp->type == COMP_DELAYED) { if ((r = ssh_packet_init_compression(ssh)) != 0) return r; if (mode == MODE_OUT) { if ((r = start_compression_out(ssh, 6)) != 0) return r; } else { if ((r = start_compression_in(ssh)) != 0) return r; } comp->enabled = 1; } } return 0; } /* Used to mute debug logging for noisy packet types */ static int ssh_packet_log_type(u_char type) { switch (type) { case SSH2_MSG_CHANNEL_DATA: case SSH2_MSG_CHANNEL_EXTENDED_DATA: case SSH2_MSG_CHANNEL_WINDOW_ADJUST: return 0; default: return 1; } } /* * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue) */ int ssh_packet_send2_wrapped(struct ssh *ssh) { struct session_state *state = ssh->state; u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH]; u_char padlen, pad = 0; u_int authlen = 0, aadlen = 0; u_int len; struct sshenc *enc = NULL; struct sshmac *mac = NULL; struct sshcomp *comp = NULL; int r, block_size; if (state->newkeys[MODE_OUT] != NULL) { enc = &state->newkeys[MODE_OUT]->enc; mac = &state->newkeys[MODE_OUT]->mac; comp = &state->newkeys[MODE_OUT]->comp; /* disable mac for authenticated encryption */ if ((authlen = cipher_authlen(enc->cipher)) != 0) mac = NULL; } block_size = enc ? enc->block_size : 8; aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0; type = (sshbuf_ptr(state->outgoing_packet))[5]; if (ssh_packet_log_type(type)) debug3("send packet: type %u", type); #ifdef PACKET_DEBUG fprintf(stderr, "plain: "); sshbuf_dump(state->outgoing_packet, stderr); #endif if (comp && comp->enabled) { len = sshbuf_len(state->outgoing_packet); /* skip header, compress only payload */ if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0) goto out; sshbuf_reset(state->compression_buffer); if ((r = compress_buffer(ssh, state->outgoing_packet, state->compression_buffer)) != 0) goto out; sshbuf_reset(state->outgoing_packet); if ((r = sshbuf_put(state->outgoing_packet, "\0\0\0\0\0", 5)) != 0 || (r = sshbuf_putb(state->outgoing_packet, state->compression_buffer)) != 0) goto out; DBG(debug("compression: raw %d compressed %zd", len, sshbuf_len(state->outgoing_packet))); } /* sizeof (packet_len + pad_len + payload) */ len = sshbuf_len(state->outgoing_packet); /* * calc size of padding, alloc space, get random data, * minimum padding is 4 bytes */ len -= aadlen; /* packet length is not encrypted for EtM modes */ padlen = block_size - (len % block_size); if (padlen < 4) padlen += block_size; if (state->extra_pad) { /* will wrap if extra_pad+padlen > 255 */ state->extra_pad = roundup(state->extra_pad, block_size); pad = state->extra_pad - ((len + padlen) % state->extra_pad); DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)", __func__, pad, len, padlen, state->extra_pad)); padlen += pad; state->extra_pad = 0; } if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0) goto out; if (enc && !state->send_context.plaintext) { /* random padding */ arc4random_buf(cp, padlen); } else { /* clear padding */ explicit_bzero(cp, padlen); } /* sizeof (packet_len + pad_len + payload + padding) */ len = sshbuf_len(state->outgoing_packet); cp = sshbuf_mutable_ptr(state->outgoing_packet); if (cp == NULL) { r = SSH_ERR_INTERNAL_ERROR; goto out; } /* packet_length includes payload, padding and padding length field */ POKE_U32(cp, len - 4); cp[4] = padlen; DBG(debug("send: len %d (includes padlen %d, aadlen %d)", len, padlen, aadlen)); /* compute MAC over seqnr and packet(length fields, payload, padding) */ if (mac && mac->enabled && !mac->etm) { if ((r = mac_compute(mac, state->p_send.seqnr, sshbuf_ptr(state->outgoing_packet), len, macbuf, sizeof(macbuf))) != 0) goto out; DBG(debug("done calc MAC out #%d", state->p_send.seqnr)); } /* encrypt packet and append to output buffer. */ if ((r = sshbuf_reserve(state->output, sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0) goto out; if ((r = cipher_crypt(&state->send_context, state->p_send.seqnr, cp, sshbuf_ptr(state->outgoing_packet), len - aadlen, aadlen, authlen)) != 0) goto out; /* append unencrypted MAC */ if (mac && mac->enabled) { if (mac->etm) { /* EtM: compute mac over aadlen + cipher text */ if ((r = mac_compute(mac, state->p_send.seqnr, cp, len, macbuf, sizeof(macbuf))) != 0) goto out; DBG(debug("done calc MAC(EtM) out #%d", state->p_send.seqnr)); } if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0) goto out; } #ifdef PACKET_DEBUG fprintf(stderr, "encrypted: "); sshbuf_dump(state->output, stderr); #endif /* increment sequence number for outgoing packets */ if (++state->p_send.seqnr == 0) logit("outgoing seqnr wraps around"); if (++state->p_send.packets == 0) if (!(ssh->compat & SSH_BUG_NOREKEY)) return SSH_ERR_NEED_REKEY; state->p_send.blocks += len / block_size; state->p_send.bytes += len; sshbuf_reset(state->outgoing_packet); if (type == SSH2_MSG_NEWKEYS) r = ssh_set_newkeys(ssh, MODE_OUT); else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side) r = ssh_packet_enable_delayed_compress(ssh); else r = 0; out: return r; } /* returns non-zero if the specified packet type is usec by KEX */ static int ssh_packet_type_is_kex(u_char type) { return type >= SSH2_MSG_TRANSPORT_MIN && type <= SSH2_MSG_TRANSPORT_MAX && type != SSH2_MSG_SERVICE_REQUEST && type != SSH2_MSG_SERVICE_ACCEPT && type != SSH2_MSG_EXT_INFO; } int ssh_packet_send2(struct ssh *ssh) { struct session_state *state = ssh->state; struct packet *p; u_char type; int r, need_rekey; if (sshbuf_len(state->outgoing_packet) < 6) return SSH_ERR_INTERNAL_ERROR; type = sshbuf_ptr(state->outgoing_packet)[5]; need_rekey = !ssh_packet_type_is_kex(type) && ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet)); /* * During rekeying we can only send key exchange messages. * Queue everything else. */ if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) { if (need_rekey) debug3("%s: rekex triggered", __func__); debug("enqueue packet: %u", type); p = calloc(1, sizeof(*p)); if (p == NULL) return SSH_ERR_ALLOC_FAIL; p->type = type; p->payload = state->outgoing_packet; TAILQ_INSERT_TAIL(&state->outgoing, p, next); state->outgoing_packet = sshbuf_new(); if (state->outgoing_packet == NULL) return SSH_ERR_ALLOC_FAIL; if (need_rekey) { /* * This packet triggered a rekey, so send the * KEXINIT now. * NB. reenters this function via kex_start_rekex(). */ return kex_start_rekex(ssh); } return 0; } /* rekeying starts with sending KEXINIT */ if (type == SSH2_MSG_KEXINIT) state->rekeying = 1; if ((r = ssh_packet_send2_wrapped(ssh)) != 0) return r; /* after a NEWKEYS message we can send the complete queue */ if (type == SSH2_MSG_NEWKEYS) { state->rekeying = 0; state->rekey_time = monotime(); while ((p = TAILQ_FIRST(&state->outgoing))) { type = p->type; /* * If this packet triggers a rekex, then skip the * remaining packets in the queue for now. * NB. re-enters this function via kex_start_rekex. */ if (ssh_packet_need_rekeying(ssh, sshbuf_len(p->payload))) { debug3("%s: queued packet triggered rekex", __func__); return kex_start_rekex(ssh); } debug("dequeue packet: %u", type); sshbuf_free(state->outgoing_packet); state->outgoing_packet = p->payload; TAILQ_REMOVE(&state->outgoing, p, next); memset(p, 0, sizeof(*p)); free(p); if ((r = ssh_packet_send2_wrapped(ssh)) != 0) return r; } } return 0; } /* * Waits until a packet has been received, and returns its type. Note that * no other data is processed until this returns, so this function should not * be used during the interactive session. */ int ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p) { struct session_state *state = ssh->state; int len, r, ms_remain; fd_set *setp; char buf[8192]; struct timeval timeout, start, *timeoutp = NULL; DBG(debug("packet_read()")); setp = calloc(howmany(state->connection_in + 1, NFDBITS), sizeof(fd_mask)); if (setp == NULL) return SSH_ERR_ALLOC_FAIL; /* * Since we are blocking, ensure that all written packets have * been sent. */ if ((r = ssh_packet_write_wait(ssh)) != 0) goto out; /* Stay in the loop until we have received a complete packet. */ for (;;) { /* Try to read a packet from the buffer. */ r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p); if (r != 0) break; if (!compat20 && ( *typep == SSH_SMSG_SUCCESS || *typep == SSH_SMSG_FAILURE || *typep == SSH_CMSG_EOF || *typep == SSH_CMSG_EXIT_CONFIRMATION)) if ((r = sshpkt_get_end(ssh)) != 0) break; /* If we got a packet, return it. */ if (*typep != SSH_MSG_NONE) break; /* * Otherwise, wait for some data to arrive, add it to the * buffer, and try again. */ memset(setp, 0, howmany(state->connection_in + 1, NFDBITS) * sizeof(fd_mask)); FD_SET(state->connection_in, setp); if (state->packet_timeout_ms > 0) { ms_remain = state->packet_timeout_ms; timeoutp = &timeout; } /* Wait for some data to arrive. */ for (;;) { if (state->packet_timeout_ms != -1) { ms_to_timeval(&timeout, ms_remain); gettimeofday(&start, NULL); } if ((r = select(state->connection_in + 1, setp, NULL, NULL, timeoutp)) >= 0) break; if (errno != EAGAIN && errno != EINTR && errno != EWOULDBLOCK) break; if (state->packet_timeout_ms == -1) continue; ms_subtract_diff(&start, &ms_remain); if (ms_remain <= 0) { r = 0; break; } } if (r == 0) return SSH_ERR_CONN_TIMEOUT; /* Read data from the socket. */ len = read(state->connection_in, buf, sizeof(buf)); if (len == 0) { r = SSH_ERR_CONN_CLOSED; goto out; } if (len < 0) { r = SSH_ERR_SYSTEM_ERROR; goto out; } /* Append it to the buffer. */ if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0) goto out; } out: free(setp); return r; } int ssh_packet_read(struct ssh *ssh) { u_char type; int r; if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0) fatal("%s: %s", __func__, ssh_err(r)); return type; } /* * Waits until a packet has been received, verifies that its type matches * that given, and gives a fatal error and exits if there is a mismatch. */ int ssh_packet_read_expect(struct ssh *ssh, u_int expected_type) { int r; u_char type; if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0) return r; if (type != expected_type) { if ((r = sshpkt_disconnect(ssh, "Protocol error: expected packet type %d, got %d", expected_type, type)) != 0) return r; return SSH_ERR_PROTOCOL_ERROR; } return 0; } /* Checks if a full packet is available in the data received so far via * packet_process_incoming. If so, reads the packet; otherwise returns * SSH_MSG_NONE. This does not wait for data from the connection. * * SSH_MSG_DISCONNECT is handled specially here. Also, * SSH_MSG_IGNORE messages are skipped by this function and are never returned * to higher levels. */ int ssh_packet_read_poll1(struct ssh *ssh, u_char *typep) { struct session_state *state = ssh->state; u_int len, padded_len; const char *emsg; const u_char *cp; u_char *p; u_int checksum, stored_checksum; int r; *typep = SSH_MSG_NONE; /* Check if input size is less than minimum packet size. */ if (sshbuf_len(state->input) < 4 + 8) return 0; /* Get length of incoming packet. */ len = PEEK_U32(sshbuf_ptr(state->input)); if (len < 1 + 2 + 2 || len > 256 * 1024) { if ((r = sshpkt_disconnect(ssh, "Bad packet length %u", len)) != 0) return r; return SSH_ERR_CONN_CORRUPT; } padded_len = (len + 8) & ~7; /* Check if the packet has been entirely received. */ if (sshbuf_len(state->input) < 4 + padded_len) return 0; /* The entire packet is in buffer. */ /* Consume packet length. */ if ((r = sshbuf_consume(state->input, 4)) != 0) goto out; /* * Cryptographic attack detector for ssh * (C)1998 CORE-SDI, Buenos Aires Argentina * Ariel Futoransky(futo@core-sdi.com) */ if (!state->receive_context.plaintext) { emsg = NULL; switch (detect_attack(&state->deattack, sshbuf_ptr(state->input), padded_len)) { case DEATTACK_OK: break; case DEATTACK_DETECTED: emsg = "crc32 compensation attack detected"; break; case DEATTACK_DOS_DETECTED: emsg = "deattack denial of service detected"; break; default: emsg = "deattack error"; break; } if (emsg != NULL) { error("%s", emsg); if ((r = sshpkt_disconnect(ssh, "%s", emsg)) != 0 || (r = ssh_packet_write_wait(ssh)) != 0) return r; return SSH_ERR_CONN_CORRUPT; } } /* Decrypt data to incoming_packet. */ sshbuf_reset(state->incoming_packet); if ((r = sshbuf_reserve(state->incoming_packet, padded_len, &p)) != 0) goto out; if ((r = cipher_crypt(&state->receive_context, 0, p, sshbuf_ptr(state->input), padded_len, 0, 0)) != 0) goto out; if ((r = sshbuf_consume(state->input, padded_len)) != 0) goto out; #ifdef PACKET_DEBUG fprintf(stderr, "read_poll plain: "); sshbuf_dump(state->incoming_packet, stderr); #endif /* Compute packet checksum. */ checksum = ssh_crc32(sshbuf_ptr(state->incoming_packet), sshbuf_len(state->incoming_packet) - 4); /* Skip padding. */ if ((r = sshbuf_consume(state->incoming_packet, 8 - len % 8)) != 0) goto out; /* Test check bytes. */ if (len != sshbuf_len(state->incoming_packet)) { error("%s: len %d != sshbuf_len %zd", __func__, len, sshbuf_len(state->incoming_packet)); if ((r = sshpkt_disconnect(ssh, "invalid packet length")) != 0 || (r = ssh_packet_write_wait(ssh)) != 0) return r; return SSH_ERR_CONN_CORRUPT; } cp = sshbuf_ptr(state->incoming_packet) + len - 4; stored_checksum = PEEK_U32(cp); if (checksum != stored_checksum) { error("Corrupted check bytes on input"); if ((r = sshpkt_disconnect(ssh, "connection corrupted")) != 0 || (r = ssh_packet_write_wait(ssh)) != 0) return r; return SSH_ERR_CONN_CORRUPT; } if ((r = sshbuf_consume_end(state->incoming_packet, 4)) < 0) goto out; if (state->packet_compression) { sshbuf_reset(state->compression_buffer); if ((r = uncompress_buffer(ssh, state->incoming_packet, state->compression_buffer)) != 0) goto out; sshbuf_reset(state->incoming_packet); if ((r = sshbuf_putb(state->incoming_packet, state->compression_buffer)) != 0) goto out; } state->p_read.packets++; state->p_read.bytes += padded_len + 4; if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0) goto out; if (*typep < SSH_MSG_MIN || *typep > SSH_MSG_MAX) { error("Invalid ssh1 packet type: %d", *typep); if ((r = sshpkt_disconnect(ssh, "invalid packet type")) != 0 || (r = ssh_packet_write_wait(ssh)) != 0) return r; return SSH_ERR_PROTOCOL_ERROR; } r = 0; out: return r; } int ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p) { struct session_state *state = ssh->state; u_int padlen, need; u_char *cp, macbuf[SSH_DIGEST_MAX_LENGTH]; u_int maclen, aadlen = 0, authlen = 0, block_size; struct sshenc *enc = NULL; struct sshmac *mac = NULL; struct sshcomp *comp = NULL; int r; *typep = SSH_MSG_NONE; if (state->packet_discard) return 0; if (state->newkeys[MODE_IN] != NULL) { enc = &state->newkeys[MODE_IN]->enc; mac = &state->newkeys[MODE_IN]->mac; comp = &state->newkeys[MODE_IN]->comp; /* disable mac for authenticated encryption */ if ((authlen = cipher_authlen(enc->cipher)) != 0) mac = NULL; } maclen = mac && mac->enabled ? mac->mac_len : 0; block_size = enc ? enc->block_size : 8; aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0; if (aadlen && state->packlen == 0) { if (cipher_get_length(&state->receive_context, &state->packlen, state->p_read.seqnr, sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0) return 0; if (state->packlen < 1 + 4 || state->packlen > PACKET_MAX_SIZE) { #ifdef PACKET_DEBUG sshbuf_dump(state->input, stderr); #endif logit("Bad packet length %u.", state->packlen); if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0) return r; return SSH_ERR_CONN_CORRUPT; } sshbuf_reset(state->incoming_packet); } else if (state->packlen == 0) { /* * check if input size is less than the cipher block size, * decrypt first block and extract length of incoming packet */ if (sshbuf_len(state->input) < block_size) return 0; sshbuf_reset(state->incoming_packet); if ((r = sshbuf_reserve(state->incoming_packet, block_size, &cp)) != 0) goto out; if ((r = cipher_crypt(&state->receive_context, state->p_send.seqnr, cp, sshbuf_ptr(state->input), block_size, 0, 0)) != 0) goto out; state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet)); if (state->packlen < 1 + 4 || state->packlen > PACKET_MAX_SIZE) { #ifdef PACKET_DEBUG fprintf(stderr, "input: \n"); sshbuf_dump(state->input, stderr); fprintf(stderr, "incoming_packet: \n"); sshbuf_dump(state->incoming_packet, stderr); #endif logit("Bad packet length %u.", state->packlen); return ssh_packet_start_discard(ssh, enc, mac, state->packlen, PACKET_MAX_SIZE); } if ((r = sshbuf_consume(state->input, block_size)) != 0) goto out; } DBG(debug("input: packet len %u", state->packlen+4)); if (aadlen) { /* only the payload is encrypted */ need = state->packlen; } else { /* * the payload size and the payload are encrypted, but we * have a partial packet of block_size bytes */ need = 4 + state->packlen - block_size; } DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d," " aadlen %d", block_size, need, maclen, authlen, aadlen)); if (need % block_size != 0) { logit("padding error: need %d block %d mod %d", need, block_size, need % block_size); return ssh_packet_start_discard(ssh, enc, mac, state->packlen, PACKET_MAX_SIZE - block_size); } /* * check if the entire packet has been received and * decrypt into incoming_packet: * 'aadlen' bytes are unencrypted, but authenticated. * 'need' bytes are encrypted, followed by either * 'authlen' bytes of authentication tag or * 'maclen' bytes of message authentication code. */ if (sshbuf_len(state->input) < aadlen + need + authlen + maclen) return 0; #ifdef PACKET_DEBUG fprintf(stderr, "read_poll enc/full: "); sshbuf_dump(state->input, stderr); #endif /* EtM: compute mac over encrypted input */ if (mac && mac->enabled && mac->etm) { if ((r = mac_compute(mac, state->p_read.seqnr, sshbuf_ptr(state->input), aadlen + need, macbuf, sizeof(macbuf))) != 0) goto out; } if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need, &cp)) != 0) goto out; if ((r = cipher_crypt(&state->receive_context, state->p_read.seqnr, cp, sshbuf_ptr(state->input), need, aadlen, authlen)) != 0) goto out; if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0) goto out; /* * compute MAC over seqnr and packet, * increment sequence number for incoming packet */ if (mac && mac->enabled) { if (!mac->etm) if ((r = mac_compute(mac, state->p_read.seqnr, sshbuf_ptr(state->incoming_packet), sshbuf_len(state->incoming_packet), macbuf, sizeof(macbuf))) != 0) goto out; if (timingsafe_bcmp(macbuf, sshbuf_ptr(state->input), mac->mac_len) != 0) { logit("Corrupted MAC on input."); if (need > PACKET_MAX_SIZE) return SSH_ERR_INTERNAL_ERROR; return ssh_packet_start_discard(ssh, enc, mac, state->packlen, PACKET_MAX_SIZE - need); } DBG(debug("MAC #%d ok", state->p_read.seqnr)); if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0) goto out; } if (seqnr_p != NULL) *seqnr_p = state->p_read.seqnr; if (++state->p_read.seqnr == 0) logit("incoming seqnr wraps around"); if (++state->p_read.packets == 0) if (!(ssh->compat & SSH_BUG_NOREKEY)) return SSH_ERR_NEED_REKEY; state->p_read.blocks += (state->packlen + 4) / block_size; state->p_read.bytes += state->packlen + 4; /* get padlen */ padlen = sshbuf_ptr(state->incoming_packet)[4]; DBG(debug("input: padlen %d", padlen)); if (padlen < 4) { if ((r = sshpkt_disconnect(ssh, "Corrupted padlen %d on input.", padlen)) != 0 || (r = ssh_packet_write_wait(ssh)) != 0) return r; return SSH_ERR_CONN_CORRUPT; } /* skip packet size + padlen, discard padding */ if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 || ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0)) goto out; DBG(debug("input: len before de-compress %zd", sshbuf_len(state->incoming_packet))); if (comp && comp->enabled) { sshbuf_reset(state->compression_buffer); if ((r = uncompress_buffer(ssh, state->incoming_packet, state->compression_buffer)) != 0) goto out; sshbuf_reset(state->incoming_packet); if ((r = sshbuf_putb(state->incoming_packet, state->compression_buffer)) != 0) goto out; DBG(debug("input: len after de-compress %zd", sshbuf_len(state->incoming_packet))); } /* * get packet type, implies consume. * return length of payload (without type field) */ if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0) goto out; if (ssh_packet_log_type(*typep)) debug3("receive packet: type %u", *typep); if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) { if ((r = sshpkt_disconnect(ssh, "Invalid ssh2 packet type: %d", *typep)) != 0 || (r = ssh_packet_write_wait(ssh)) != 0) return r; return SSH_ERR_PROTOCOL_ERROR; } if (*typep == SSH2_MSG_NEWKEYS) r = ssh_set_newkeys(ssh, MODE_IN); else if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side) r = ssh_packet_enable_delayed_compress(ssh); else r = 0; #ifdef PACKET_DEBUG fprintf(stderr, "read/plain[%d]:\r\n", *typep); sshbuf_dump(state->incoming_packet, stderr); #endif /* reset for next packet */ state->packlen = 0; /* do we need to rekey? */ if (ssh_packet_need_rekeying(ssh, 0)) { debug3("%s: rekex triggered", __func__); if ((r = kex_start_rekex(ssh)) != 0) return r; } out: return r; } int ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p) { struct session_state *state = ssh->state; u_int reason, seqnr; int r; u_char *msg; for (;;) { msg = NULL; if (compat20) { r = ssh_packet_read_poll2(ssh, typep, seqnr_p); if (r != 0) return r; if (*typep) { state->keep_alive_timeouts = 0; DBG(debug("received packet type %d", *typep)); } switch (*typep) { case SSH2_MSG_IGNORE: debug3("Received SSH2_MSG_IGNORE"); break; case SSH2_MSG_DEBUG: if ((r = sshpkt_get_u8(ssh, NULL)) != 0 || (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 || (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) { free(msg); return r; } debug("Remote: %.900s", msg); free(msg); break; case SSH2_MSG_DISCONNECT: if ((r = sshpkt_get_u32(ssh, &reason)) != 0 || (r = sshpkt_get_string(ssh, &msg, NULL)) != 0) return r; /* Ignore normal client exit notifications */ do_log2(ssh->state->server_side && reason == SSH2_DISCONNECT_BY_APPLICATION ? SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR, "Received disconnect from %s port %d:" "%u: %.400s", ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), reason, msg); free(msg); return SSH_ERR_DISCONNECTED; case SSH2_MSG_UNIMPLEMENTED: if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0) return r; debug("Received SSH2_MSG_UNIMPLEMENTED for %u", seqnr); break; default: return 0; } } else { r = ssh_packet_read_poll1(ssh, typep); switch (*typep) { case SSH_MSG_NONE: return SSH_MSG_NONE; case SSH_MSG_IGNORE: break; case SSH_MSG_DEBUG: if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0) return r; debug("Remote: %.900s", msg); free(msg); break; case SSH_MSG_DISCONNECT: if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0) return r; logit("Received disconnect from %s port %d: " "%.400s", ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), msg); free(msg); return SSH_ERR_DISCONNECTED; default: DBG(debug("received packet type %d", *typep)); return 0; } } } } /* * Buffers the given amount of input characters. This is intended to be used * together with packet_read_poll. */ int ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len) { struct session_state *state = ssh->state; int r; if (state->packet_discard) { state->keep_alive_timeouts = 0; /* ?? */ if (len >= state->packet_discard) { if ((r = ssh_packet_stop_discard(ssh)) != 0) return r; } state->packet_discard -= len; return 0; } if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0) return r; return 0; } int ssh_packet_remaining(struct ssh *ssh) { return sshbuf_len(ssh->state->incoming_packet); } /* * Sends a diagnostic message from the server to the client. This message * can be sent at any time (but not while constructing another message). The * message is printed immediately, but only if the client is being executed * in verbose mode. These messages are primarily intended to ease debugging * authentication problems. The length of the formatted message must not * exceed 1024 bytes. This will automatically call ssh_packet_write_wait. */ void ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...) { char buf[1024]; va_list args; int r; if (compat20 && (ssh->compat & SSH_BUG_DEBUG)) return; va_start(args, fmt); vsnprintf(buf, sizeof(buf), fmt, args); va_end(args); if (compat20) { if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 || (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */ (r = sshpkt_put_cstring(ssh, buf)) != 0 || (r = sshpkt_put_cstring(ssh, "")) != 0 || (r = sshpkt_send(ssh)) != 0) fatal("%s: %s", __func__, ssh_err(r)); } else { if ((r = sshpkt_start(ssh, SSH_MSG_DEBUG)) != 0 || (r = sshpkt_put_cstring(ssh, buf)) != 0 || (r = sshpkt_send(ssh)) != 0) fatal("%s: %s", __func__, ssh_err(r)); } if ((r = ssh_packet_write_wait(ssh)) != 0) fatal("%s: %s", __func__, ssh_err(r)); } /* * Pretty-print connection-terminating errors and exit. */ void sshpkt_fatal(struct ssh *ssh, const char *tag, int r) { switch (r) { case SSH_ERR_CONN_CLOSED: logit("Connection closed by %.200s port %d", ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); cleanup_exit(255); case SSH_ERR_CONN_TIMEOUT: logit("Connection %s %.200s port %d timed out", ssh->state->server_side ? "from" : "to", ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); cleanup_exit(255); case SSH_ERR_DISCONNECTED: logit("Disconnected from %.200s port %d", ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); cleanup_exit(255); case SSH_ERR_SYSTEM_ERROR: if (errno == ECONNRESET) { logit("Connection reset by %.200s port %d", ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); cleanup_exit(255); } /* FALLTHROUGH */ case SSH_ERR_NO_CIPHER_ALG_MATCH: case SSH_ERR_NO_MAC_ALG_MATCH: case SSH_ERR_NO_COMPRESS_ALG_MATCH: case SSH_ERR_NO_KEX_ALG_MATCH: case SSH_ERR_NO_HOSTKEY_ALG_MATCH: if (ssh && ssh->kex && ssh->kex->failed_choice) { + BLACKLIST_NOTIFY(BLACKLIST_AUTH_FAIL); fatal("Unable to negotiate with %.200s port %d: %s. " "Their offer: %s", ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), ssh_err(r), ssh->kex->failed_choice); } /* FALLTHROUGH */ default: fatal("%s%sConnection %s %.200s port %d: %s", tag != NULL ? tag : "", tag != NULL ? ": " : "", ssh->state->server_side ? "from" : "to", ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), ssh_err(r)); } } /* * Logs the error plus constructs and sends a disconnect packet, closes the * connection, and exits. This function never returns. The error message * should not contain a newline. The length of the formatted message must * not exceed 1024 bytes. */ void ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...) { char buf[1024]; va_list args; static int disconnecting = 0; int r; if (disconnecting) /* Guard against recursive invocations. */ fatal("packet_disconnect called recursively."); disconnecting = 1; /* * Format the message. Note that the caller must make sure the * message is of limited size. */ va_start(args, fmt); vsnprintf(buf, sizeof(buf), fmt, args); va_end(args); /* Display the error locally */ logit("Disconnecting: %.100s", buf); /* * Send the disconnect message to the other side, and wait * for it to get sent. */ if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0) sshpkt_fatal(ssh, __func__, r); if ((r = ssh_packet_write_wait(ssh)) != 0) sshpkt_fatal(ssh, __func__, r); /* Close the connection. */ ssh_packet_close(ssh); cleanup_exit(255); } /* * Checks if there is any buffered output, and tries to write some of * the output. */ int ssh_packet_write_poll(struct ssh *ssh) { struct session_state *state = ssh->state; int len = sshbuf_len(state->output); int r; if (len > 0) { len = write(state->connection_out, sshbuf_ptr(state->output), len); if (len == -1) { if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK) return 0; return SSH_ERR_SYSTEM_ERROR; } if (len == 0) return SSH_ERR_CONN_CLOSED; if ((r = sshbuf_consume(state->output, len)) != 0) return r; } return 0; } /* * Calls packet_write_poll repeatedly until all pending output data has been * written. */ int ssh_packet_write_wait(struct ssh *ssh) { fd_set *setp; int ret, r, ms_remain = 0; struct timeval start, timeout, *timeoutp = NULL; struct session_state *state = ssh->state; setp = calloc(howmany(state->connection_out + 1, NFDBITS), sizeof(fd_mask)); if (setp == NULL) return SSH_ERR_ALLOC_FAIL; if ((r = ssh_packet_write_poll(ssh)) != 0) { free(setp); return r; } while (ssh_packet_have_data_to_write(ssh)) { memset(setp, 0, howmany(state->connection_out + 1, NFDBITS) * sizeof(fd_mask)); FD_SET(state->connection_out, setp); if (state->packet_timeout_ms > 0) { ms_remain = state->packet_timeout_ms; timeoutp = &timeout; } for (;;) { if (state->packet_timeout_ms != -1) { ms_to_timeval(&timeout, ms_remain); gettimeofday(&start, NULL); } if ((ret = select(state->connection_out + 1, NULL, setp, NULL, timeoutp)) >= 0) break; if (errno != EAGAIN && errno != EINTR && errno != EWOULDBLOCK) break; if (state->packet_timeout_ms == -1) continue; ms_subtract_diff(&start, &ms_remain); if (ms_remain <= 0) { ret = 0; break; } } if (ret == 0) { free(setp); return SSH_ERR_CONN_TIMEOUT; } if ((r = ssh_packet_write_poll(ssh)) != 0) { free(setp); return r; } } free(setp); return 0; } /* Returns true if there is buffered data to write to the connection. */ int ssh_packet_have_data_to_write(struct ssh *ssh) { return sshbuf_len(ssh->state->output) != 0; } /* Returns true if there is not too much data to write to the connection. */ int ssh_packet_not_very_much_data_to_write(struct ssh *ssh) { if (ssh->state->interactive_mode) return sshbuf_len(ssh->state->output) < 16384; else return sshbuf_len(ssh->state->output) < 128 * 1024; } void ssh_packet_set_tos(struct ssh *ssh, int tos) { #ifndef IP_TOS_IS_BROKEN if (!ssh_packet_connection_is_on_socket(ssh)) return; switch (ssh_packet_connection_af(ssh)) { # ifdef IP_TOS case AF_INET: debug3("%s: set IP_TOS 0x%02x", __func__, tos); if (setsockopt(ssh->state->connection_in, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) error("setsockopt IP_TOS %d: %.100s:", tos, strerror(errno)); break; # endif /* IP_TOS */ # ifdef IPV6_TCLASS case AF_INET6: debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos); if (setsockopt(ssh->state->connection_in, IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0) error("setsockopt IPV6_TCLASS %d: %.100s:", tos, strerror(errno)); break; # endif /* IPV6_TCLASS */ } #endif /* IP_TOS_IS_BROKEN */ } /* Informs that the current session is interactive. Sets IP flags for that. */ void ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk) { struct session_state *state = ssh->state; if (state->set_interactive_called) return; state->set_interactive_called = 1; /* Record that we are in interactive mode. */ state->interactive_mode = interactive; /* Only set socket options if using a socket. */ if (!ssh_packet_connection_is_on_socket(ssh)) return; set_nodelay(state->connection_in); ssh_packet_set_tos(ssh, interactive ? qos_interactive : qos_bulk); } /* Returns true if the current connection is interactive. */ int ssh_packet_is_interactive(struct ssh *ssh) { return ssh->state->interactive_mode; } int ssh_packet_set_maxsize(struct ssh *ssh, u_int s) { struct session_state *state = ssh->state; if (state->set_maxsize_called) { logit("packet_set_maxsize: called twice: old %d new %d", state->max_packet_size, s); return -1; } if (s < 4 * 1024 || s > 1024 * 1024) { logit("packet_set_maxsize: bad size %d", s); return -1; } state->set_maxsize_called = 1; debug("packet_set_maxsize: setting to %d", s); state->max_packet_size = s; return s; } int ssh_packet_inc_alive_timeouts(struct ssh *ssh) { return ++ssh->state->keep_alive_timeouts; } void ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka) { ssh->state->keep_alive_timeouts = ka; } u_int ssh_packet_get_maxsize(struct ssh *ssh) { return ssh->state->max_packet_size; } /* * 9.2. Ignored Data Message * * byte SSH_MSG_IGNORE * string data * * All implementations MUST understand (and ignore) this message at any * time (after receiving the protocol version). No implementation is * required to send them. This message can be used as an additional * protection measure against advanced traffic analysis techniques. */ void ssh_packet_send_ignore(struct ssh *ssh, int nbytes) { u_int32_t rnd = 0; int r, i; if ((r = sshpkt_start(ssh, compat20 ? SSH2_MSG_IGNORE : SSH_MSG_IGNORE)) != 0 || (r = sshpkt_put_u32(ssh, nbytes)) != 0) fatal("%s: %s", __func__, ssh_err(r)); for (i = 0; i < nbytes; i++) { if (i % 4 == 0) rnd = arc4random(); if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0) fatal("%s: %s", __func__, ssh_err(r)); rnd >>= 8; } } void ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, time_t seconds) { debug3("rekey after %llu bytes, %d seconds", (unsigned long long)bytes, (int)seconds); ssh->state->rekey_limit = bytes; ssh->state->rekey_interval = seconds; } time_t ssh_packet_get_rekey_timeout(struct ssh *ssh) { time_t seconds; seconds = ssh->state->rekey_time + ssh->state->rekey_interval - monotime(); return (seconds <= 0 ? 1 : seconds); } void ssh_packet_set_server(struct ssh *ssh) { ssh->state->server_side = 1; } void ssh_packet_set_authenticated(struct ssh *ssh) { ssh->state->after_authentication = 1; } void * ssh_packet_get_input(struct ssh *ssh) { return (void *)ssh->state->input; } void * ssh_packet_get_output(struct ssh *ssh) { return (void *)ssh->state->output; } /* Reset after_authentication and reset compression in post-auth privsep */ static int ssh_packet_set_postauth(struct ssh *ssh) { struct sshcomp *comp; int r, mode; debug("%s: called", __func__); /* This was set in net child, but is not visible in user child */ ssh->state->after_authentication = 1; ssh->state->rekeying = 0; for (mode = 0; mode < MODE_MAX; mode++) { if (ssh->state->newkeys[mode] == NULL) continue; comp = &ssh->state->newkeys[mode]->comp; if (comp && comp->enabled && (r = ssh_packet_init_compression(ssh)) != 0) return r; } return 0; } /* Packet state (de-)serialization for privsep */ /* turn kex into a blob for packet state serialization */ static int kex_to_blob(struct sshbuf *m, struct kex *kex) { int r; if ((r = sshbuf_put_string(m, kex->session_id, kex->session_id_len)) != 0 || (r = sshbuf_put_u32(m, kex->we_need)) != 0 || (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 || (r = sshbuf_put_u32(m, kex->kex_type)) != 0 || (r = sshbuf_put_stringb(m, kex->my)) != 0 || (r = sshbuf_put_stringb(m, kex->peer)) != 0 || (r = sshbuf_put_u32(m, kex->flags)) != 0 || (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 || (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0) return r; return 0; } /* turn key exchange results into a blob for packet state serialization */ static int newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode) { struct sshbuf *b; struct sshcipher_ctx *cc; struct sshcomp *comp; struct sshenc *enc; struct sshmac *mac; struct newkeys *newkey; int r; if ((newkey = ssh->state->newkeys[mode]) == NULL) return SSH_ERR_INTERNAL_ERROR; enc = &newkey->enc; mac = &newkey->mac; comp = &newkey->comp; cc = (mode == MODE_OUT) ? &ssh->state->send_context : &ssh->state->receive_context; if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0) return r; if ((b = sshbuf_new()) == NULL) return SSH_ERR_ALLOC_FAIL; /* The cipher struct is constant and shared, you export pointer */ if ((r = sshbuf_put_cstring(b, enc->name)) != 0 || (r = sshbuf_put(b, &enc->cipher, sizeof(enc->cipher))) != 0 || (r = sshbuf_put_u32(b, enc->enabled)) != 0 || (r = sshbuf_put_u32(b, enc->block_size)) != 0 || (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 || (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0) goto out; if (cipher_authlen(enc->cipher) == 0) { if ((r = sshbuf_put_cstring(b, mac->name)) != 0 || (r = sshbuf_put_u32(b, mac->enabled)) != 0 || (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0) goto out; } if ((r = sshbuf_put_u32(b, comp->type)) != 0 || (r = sshbuf_put_u32(b, comp->enabled)) != 0 || (r = sshbuf_put_cstring(b, comp->name)) != 0) goto out; r = sshbuf_put_stringb(m, b); out: sshbuf_free(b); return r; } /* serialize packet state into a blob */ int ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m) { struct session_state *state = ssh->state; u_char *p; size_t slen, rlen; int r, ssh1cipher; if (!compat20) { ssh1cipher = cipher_get_number(state->receive_context.cipher); slen = cipher_get_keyiv_len(&state->send_context); rlen = cipher_get_keyiv_len(&state->receive_context); if ((r = sshbuf_put_u32(m, state->remote_protocol_flags)) != 0 || (r = sshbuf_put_u32(m, ssh1cipher)) != 0 || (r = sshbuf_put_string(m, state->ssh1_key, state->ssh1_keylen)) != 0 || (r = sshbuf_put_u32(m, slen)) != 0 || (r = sshbuf_reserve(m, slen, &p)) != 0 || (r = cipher_get_keyiv(&state->send_context, p, slen)) != 0 || (r = sshbuf_put_u32(m, rlen)) != 0 || (r = sshbuf_reserve(m, rlen, &p)) != 0 || (r = cipher_get_keyiv(&state->receive_context, p, rlen)) != 0) return r; } else { if ((r = kex_to_blob(m, ssh->kex)) != 0 || (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 || (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 || (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 || (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 || (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 || (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 || (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 || (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 || (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 || (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 || (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 || (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0) return r; } slen = cipher_get_keycontext(&state->send_context, NULL); rlen = cipher_get_keycontext(&state->receive_context, NULL); if ((r = sshbuf_put_u32(m, slen)) != 0 || (r = sshbuf_reserve(m, slen, &p)) != 0) return r; if (cipher_get_keycontext(&state->send_context, p) != (int)slen) return SSH_ERR_INTERNAL_ERROR; if ((r = sshbuf_put_u32(m, rlen)) != 0 || (r = sshbuf_reserve(m, rlen, &p)) != 0) return r; if (cipher_get_keycontext(&state->receive_context, p) != (int)rlen) return SSH_ERR_INTERNAL_ERROR; if ((r = ssh_packet_get_compress_state(m, ssh)) != 0 || (r = sshbuf_put_stringb(m, state->input)) != 0 || (r = sshbuf_put_stringb(m, state->output)) != 0) return r; return 0; } /* restore key exchange results from blob for packet state de-serialization */ static int newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode) { struct sshbuf *b = NULL; struct sshcomp *comp; struct sshenc *enc; struct sshmac *mac; struct newkeys *newkey = NULL; size_t keylen, ivlen, maclen; int r; if ((newkey = calloc(1, sizeof(*newkey))) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if ((r = sshbuf_froms(m, &b)) != 0) goto out; #ifdef DEBUG_PK sshbuf_dump(b, stderr); #endif enc = &newkey->enc; mac = &newkey->mac; comp = &newkey->comp; if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 || (r = sshbuf_get(b, &enc->cipher, sizeof(enc->cipher))) != 0 || (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 || (r = sshbuf_get_u32(b, &enc->block_size)) != 0 || (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 || (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0) goto out; if (cipher_authlen(enc->cipher) == 0) { if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0) goto out; if ((r = mac_setup(mac, mac->name)) != 0) goto out; if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 || (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0) goto out; if (maclen > mac->key_len) { r = SSH_ERR_INVALID_FORMAT; goto out; } mac->key_len = maclen; } if ((r = sshbuf_get_u32(b, &comp->type)) != 0 || (r = sshbuf_get_u32(b, (u_int *)&comp->enabled)) != 0 || (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0) goto out; if (enc->name == NULL || cipher_by_name(enc->name) != enc->cipher) { r = SSH_ERR_INVALID_FORMAT; goto out; } if (sshbuf_len(b) != 0) { r = SSH_ERR_INVALID_FORMAT; goto out; } enc->key_len = keylen; enc->iv_len = ivlen; ssh->kex->newkeys[mode] = newkey; newkey = NULL; r = 0; out: free(newkey); sshbuf_free(b); return r; } /* restore kex from blob for packet state de-serialization */ static int kex_from_blob(struct sshbuf *m, struct kex **kexp) { struct kex *kex; int r; if ((kex = calloc(1, sizeof(struct kex))) == NULL || (kex->my = sshbuf_new()) == NULL || (kex->peer = sshbuf_new()) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 || (r = sshbuf_get_u32(m, &kex->we_need)) != 0 || (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 || (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 || (r = sshbuf_get_stringb(m, kex->my)) != 0 || (r = sshbuf_get_stringb(m, kex->peer)) != 0 || (r = sshbuf_get_u32(m, &kex->flags)) != 0 || (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 || (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0) goto out; kex->server = 1; kex->done = 1; r = 0; out: if (r != 0 || kexp == NULL) { if (kex != NULL) { sshbuf_free(kex->my); sshbuf_free(kex->peer); free(kex); } if (kexp != NULL) *kexp = NULL; } else { *kexp = kex; } return r; } /* * Restore packet state from content of blob 'm' (de-serialization). * Note that 'm' will be partially consumed on parsing or any other errors. */ int ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m) { struct session_state *state = ssh->state; const u_char *ssh1key, *ivin, *ivout, *keyin, *keyout, *input, *output; size_t ssh1keylen, rlen, slen, ilen, olen; int r; u_int ssh1cipher = 0; if (!compat20) { if ((r = sshbuf_get_u32(m, &state->remote_protocol_flags)) != 0 || (r = sshbuf_get_u32(m, &ssh1cipher)) != 0 || (r = sshbuf_get_string_direct(m, &ssh1key, &ssh1keylen)) != 0 || (r = sshbuf_get_string_direct(m, &ivout, &slen)) != 0 || (r = sshbuf_get_string_direct(m, &ivin, &rlen)) != 0) return r; if (ssh1cipher > INT_MAX) return SSH_ERR_KEY_UNKNOWN_CIPHER; ssh_packet_set_encryption_key(ssh, ssh1key, ssh1keylen, (int)ssh1cipher); if (cipher_get_keyiv_len(&state->send_context) != (int)slen || cipher_get_keyiv_len(&state->receive_context) != (int)rlen) return SSH_ERR_INVALID_FORMAT; if ((r = cipher_set_keyiv(&state->send_context, ivout)) != 0 || (r = cipher_set_keyiv(&state->receive_context, ivin)) != 0) return r; } else { if ((r = kex_from_blob(m, &ssh->kex)) != 0 || (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 || (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 || (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 || (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 || (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 || (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 || (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 || (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 || (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 || (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 || (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 || (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0) return r; /* * We set the time here so that in post-auth privsep slave we * count from the completion of the authentication. */ state->rekey_time = monotime(); /* XXX ssh_set_newkeys overrides p_read.packets? XXX */ if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 || (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0) return r; } if ((r = sshbuf_get_string_direct(m, &keyout, &slen)) != 0 || (r = sshbuf_get_string_direct(m, &keyin, &rlen)) != 0) return r; if (cipher_get_keycontext(&state->send_context, NULL) != (int)slen || cipher_get_keycontext(&state->receive_context, NULL) != (int)rlen) return SSH_ERR_INVALID_FORMAT; cipher_set_keycontext(&state->send_context, keyout); cipher_set_keycontext(&state->receive_context, keyin); if ((r = ssh_packet_set_compress_state(ssh, m)) != 0 || (r = ssh_packet_set_postauth(ssh)) != 0) return r; sshbuf_reset(state->input); sshbuf_reset(state->output); if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 || (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 || (r = sshbuf_put(state->input, input, ilen)) != 0 || (r = sshbuf_put(state->output, output, olen)) != 0) return r; if (sshbuf_len(m)) return SSH_ERR_INVALID_FORMAT; debug3("%s: done", __func__); return 0; } /* NEW API */ /* put data to the outgoing packet */ int sshpkt_put(struct ssh *ssh, const void *v, size_t len) { return sshbuf_put(ssh->state->outgoing_packet, v, len); } int sshpkt_putb(struct ssh *ssh, const struct sshbuf *b) { return sshbuf_putb(ssh->state->outgoing_packet, b); } int sshpkt_put_u8(struct ssh *ssh, u_char val) { return sshbuf_put_u8(ssh->state->outgoing_packet, val); } int sshpkt_put_u32(struct ssh *ssh, u_int32_t val) { return sshbuf_put_u32(ssh->state->outgoing_packet, val); } int sshpkt_put_u64(struct ssh *ssh, u_int64_t val) { return sshbuf_put_u64(ssh->state->outgoing_packet, val); } int sshpkt_put_string(struct ssh *ssh, const void *v, size_t len) { return sshbuf_put_string(ssh->state->outgoing_packet, v, len); } int sshpkt_put_cstring(struct ssh *ssh, const void *v) { return sshbuf_put_cstring(ssh->state->outgoing_packet, v); } int sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v) { return sshbuf_put_stringb(ssh->state->outgoing_packet, v); } #ifdef WITH_OPENSSL #ifdef OPENSSL_HAS_ECC int sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g) { return sshbuf_put_ec(ssh->state->outgoing_packet, v, g); } #endif /* OPENSSL_HAS_ECC */ #ifdef WITH_SSH1 int sshpkt_put_bignum1(struct ssh *ssh, const BIGNUM *v) { return sshbuf_put_bignum1(ssh->state->outgoing_packet, v); } #endif /* WITH_SSH1 */ int sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v) { return sshbuf_put_bignum2(ssh->state->outgoing_packet, v); } #endif /* WITH_OPENSSL */ /* fetch data from the incoming packet */ int sshpkt_get(struct ssh *ssh, void *valp, size_t len) { return sshbuf_get(ssh->state->incoming_packet, valp, len); } int sshpkt_get_u8(struct ssh *ssh, u_char *valp) { return sshbuf_get_u8(ssh->state->incoming_packet, valp); } int sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp) { return sshbuf_get_u32(ssh->state->incoming_packet, valp); } int sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp) { return sshbuf_get_u64(ssh->state->incoming_packet, valp); } int sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp) { return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp); } int sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp) { return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp); } int sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp) { return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp); } #ifdef WITH_OPENSSL #ifdef OPENSSL_HAS_ECC int sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g) { return sshbuf_get_ec(ssh->state->incoming_packet, v, g); } #endif /* OPENSSL_HAS_ECC */ #ifdef WITH_SSH1 int sshpkt_get_bignum1(struct ssh *ssh, BIGNUM *v) { return sshbuf_get_bignum1(ssh->state->incoming_packet, v); } #endif /* WITH_SSH1 */ int sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v) { return sshbuf_get_bignum2(ssh->state->incoming_packet, v); } #endif /* WITH_OPENSSL */ int sshpkt_get_end(struct ssh *ssh) { if (sshbuf_len(ssh->state->incoming_packet) > 0) return SSH_ERR_UNEXPECTED_TRAILING_DATA; return 0; } const u_char * sshpkt_ptr(struct ssh *ssh, size_t *lenp) { if (lenp != NULL) *lenp = sshbuf_len(ssh->state->incoming_packet); return sshbuf_ptr(ssh->state->incoming_packet); } /* start a new packet */ int sshpkt_start(struct ssh *ssh, u_char type) { u_char buf[9]; int len; DBG(debug("packet_start[%d]", type)); len = compat20 ? 6 : 9; memset(buf, 0, len - 1); buf[len - 1] = type; sshbuf_reset(ssh->state->outgoing_packet); return sshbuf_put(ssh->state->outgoing_packet, buf, len); } /* send it */ int sshpkt_send(struct ssh *ssh) { if (compat20) return ssh_packet_send2(ssh); else return ssh_packet_send1(ssh); } int sshpkt_disconnect(struct ssh *ssh, const char *fmt,...) { char buf[1024]; va_list args; int r; va_start(args, fmt); vsnprintf(buf, sizeof(buf), fmt, args); va_end(args); if (compat20) { if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 || (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 || (r = sshpkt_put_cstring(ssh, buf)) != 0 || (r = sshpkt_put_cstring(ssh, "")) != 0 || (r = sshpkt_send(ssh)) != 0) return r; } else { if ((r = sshpkt_start(ssh, SSH_MSG_DISCONNECT)) != 0 || (r = sshpkt_put_cstring(ssh, buf)) != 0 || (r = sshpkt_send(ssh)) != 0) return r; } return 0; } /* roundup current message to pad bytes */ int sshpkt_add_padding(struct ssh *ssh, u_char pad) { ssh->state->extra_pad = pad; return 0; } diff --git a/crypto/openssh/servconf.c b/crypto/openssh/servconf.c index 6fb8be5bfd5a..66d24cefd4e2 100644 --- a/crypto/openssh/servconf.c +++ b/crypto/openssh/servconf.c @@ -1,2377 +1,2387 @@ /* $OpenBSD: servconf.c,v 1.285 2016/02/17 05:29:04 djm Exp $ */ /* * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved * * As far as I am concerned, the code I have written for this software * can be used freely for any purpose. Any derived versions of this * software must be clearly marked as such, and if the derived work is * incompatible with the protocol description in the RFC file, it must be * called by a name other than "ssh" or "Secure Shell". */ #include "includes.h" __RCSID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef HAVE_UTIL_H #include #endif #include "openbsd-compat/sys-queue.h" #include "xmalloc.h" #include "ssh.h" #include "log.h" #include "buffer.h" #include "misc.h" #include "servconf.h" #include "compat.h" #include "pathnames.h" #include "cipher.h" #include "key.h" #include "kex.h" #include "mac.h" #include "match.h" #include "channels.h" #include "groupaccess.h" #include "canohost.h" #include "packet.h" #include "hostfile.h" #include "auth.h" #include "myproposal.h" #include "digest.h" #include "version.h" static void add_listen_addr(ServerOptions *, char *, int); static void add_one_listen_addr(ServerOptions *, char *, int); /* Use of privilege separation or not */ extern int use_privsep; extern Buffer cfg; /* Initializes the server options to their default values. */ void initialize_server_options(ServerOptions *options) { memset(options, 0, sizeof(*options)); /* Portable-specific options */ options->use_pam = -1; /* Standard Options */ options->num_ports = 0; options->ports_from_cmdline = 0; options->queued_listen_addrs = NULL; options->num_queued_listens = 0; options->listen_addrs = NULL; options->address_family = -1; options->num_host_key_files = 0; options->num_host_cert_files = 0; options->host_key_agent = NULL; options->pid_file = NULL; options->server_key_bits = -1; options->login_grace_time = -1; options->key_regeneration_time = -1; options->permit_root_login = PERMIT_NOT_SET; options->ignore_rhosts = -1; options->ignore_user_known_hosts = -1; options->print_motd = -1; options->print_lastlog = -1; options->x11_forwarding = -1; options->x11_display_offset = -1; options->x11_use_localhost = -1; options->permit_tty = -1; options->permit_user_rc = -1; options->xauth_location = NULL; options->strict_modes = -1; options->tcp_keep_alive = -1; options->log_facility = SYSLOG_FACILITY_NOT_SET; options->log_level = SYSLOG_LEVEL_NOT_SET; options->rhosts_rsa_authentication = -1; options->hostbased_authentication = -1; options->hostbased_uses_name_from_packet_only = -1; options->hostbased_key_types = NULL; options->hostkeyalgorithms = NULL; options->rsa_authentication = -1; options->pubkey_authentication = -1; options->pubkey_key_types = NULL; options->kerberos_authentication = -1; options->kerberos_or_local_passwd = -1; options->kerberos_ticket_cleanup = -1; options->kerberos_get_afs_token = -1; options->gss_authentication=-1; options->gss_cleanup_creds = -1; options->gss_strict_acceptor = -1; options->password_authentication = -1; options->kbd_interactive_authentication = -1; options->challenge_response_authentication = -1; options->permit_empty_passwd = -1; options->permit_user_env = -1; options->use_login = -1; options->compression = -1; options->rekey_limit = -1; options->rekey_interval = -1; options->allow_tcp_forwarding = -1; options->allow_streamlocal_forwarding = -1; options->allow_agent_forwarding = -1; options->num_allow_users = 0; options->num_deny_users = 0; options->num_allow_groups = 0; options->num_deny_groups = 0; options->ciphers = NULL; options->macs = NULL; options->kex_algorithms = NULL; options->protocol = SSH_PROTO_UNKNOWN; options->fwd_opts.gateway_ports = -1; options->fwd_opts.streamlocal_bind_mask = (mode_t)-1; options->fwd_opts.streamlocal_bind_unlink = -1; options->num_subsystems = 0; options->max_startups_begin = -1; options->max_startups_rate = -1; options->max_startups = -1; options->max_authtries = -1; options->max_sessions = -1; options->banner = NULL; options->use_dns = -1; options->client_alive_interval = -1; options->client_alive_count_max = -1; options->num_authkeys_files = 0; options->num_accept_env = 0; options->permit_tun = -1; options->num_permitted_opens = -1; options->adm_forced_command = NULL; options->chroot_directory = NULL; options->authorized_keys_command = NULL; options->authorized_keys_command_user = NULL; options->revoked_keys_file = NULL; options->trusted_user_ca_keys = NULL; options->authorized_principals_file = NULL; options->authorized_principals_command = NULL; options->authorized_principals_command_user = NULL; options->ip_qos_interactive = -1; options->ip_qos_bulk = -1; options->version_addendum = NULL; options->fingerprint_hash = -1; + options->use_blacklist = -1; } /* Returns 1 if a string option is unset or set to "none" or 0 otherwise. */ static int option_clear_or_none(const char *o) { return o == NULL || strcasecmp(o, "none") == 0; } static void assemble_algorithms(ServerOptions *o) { if (kex_assemble_names(KEX_SERVER_ENCRYPT, &o->ciphers) != 0 || kex_assemble_names(KEX_SERVER_MAC, &o->macs) != 0 || kex_assemble_names(KEX_SERVER_KEX, &o->kex_algorithms) != 0 || kex_assemble_names(KEX_DEFAULT_PK_ALG, &o->hostkeyalgorithms) != 0 || kex_assemble_names(KEX_DEFAULT_PK_ALG, &o->hostbased_key_types) != 0 || kex_assemble_names(KEX_DEFAULT_PK_ALG, &o->pubkey_key_types) != 0) fatal("kex_assemble_names failed"); } void fill_default_server_options(ServerOptions *options) { int i; /* Portable-specific options */ if (options->use_pam == -1) options->use_pam = 1; /* Standard Options */ if (options->protocol == SSH_PROTO_UNKNOWN) options->protocol = SSH_PROTO_2; #define add_host_key_file(path) \ do { \ if (access((path), O_RDONLY) == 0) \ options->host_key_files \ [options->num_host_key_files++] = (path); \ } while (0) if (options->num_host_key_files == 0) { /* fill default hostkeys for protocols */ if (options->protocol & SSH_PROTO_1) add_host_key_file(_PATH_HOST_KEY_FILE); if (options->protocol & SSH_PROTO_2) { add_host_key_file(_PATH_HOST_RSA_KEY_FILE); add_host_key_file(_PATH_HOST_DSA_KEY_FILE); #ifdef OPENSSL_HAS_ECC add_host_key_file(_PATH_HOST_ECDSA_KEY_FILE); #endif add_host_key_file(_PATH_HOST_ED25519_KEY_FILE); } } #undef add_host_key_file if (options->num_host_key_files == 0) fatal("No host key files found"); /* No certificates by default */ if (options->num_ports == 0) options->ports[options->num_ports++] = SSH_DEFAULT_PORT; if (options->address_family == -1) options->address_family = AF_UNSPEC; if (options->listen_addrs == NULL) add_listen_addr(options, NULL, 0); if (options->pid_file == NULL) options->pid_file = xstrdup(_PATH_SSH_DAEMON_PID_FILE); if (options->server_key_bits == -1) options->server_key_bits = 1024; if (options->login_grace_time == -1) options->login_grace_time = 120; if (options->key_regeneration_time == -1) options->key_regeneration_time = 3600; if (options->permit_root_login == PERMIT_NOT_SET) options->permit_root_login = PERMIT_NO; if (options->ignore_rhosts == -1) options->ignore_rhosts = 1; if (options->ignore_user_known_hosts == -1) options->ignore_user_known_hosts = 0; if (options->print_motd == -1) options->print_motd = 1; if (options->print_lastlog == -1) options->print_lastlog = 1; if (options->x11_forwarding == -1) options->x11_forwarding = 1; if (options->x11_display_offset == -1) options->x11_display_offset = 10; if (options->x11_use_localhost == -1) options->x11_use_localhost = 1; if (options->xauth_location == NULL) options->xauth_location = xstrdup(_PATH_XAUTH); if (options->permit_tty == -1) options->permit_tty = 1; if (options->permit_user_rc == -1) options->permit_user_rc = 1; if (options->strict_modes == -1) options->strict_modes = 1; if (options->tcp_keep_alive == -1) options->tcp_keep_alive = 1; if (options->log_facility == SYSLOG_FACILITY_NOT_SET) options->log_facility = SYSLOG_FACILITY_AUTH; if (options->log_level == SYSLOG_LEVEL_NOT_SET) options->log_level = SYSLOG_LEVEL_INFO; if (options->rhosts_rsa_authentication == -1) options->rhosts_rsa_authentication = 0; if (options->hostbased_authentication == -1) options->hostbased_authentication = 0; if (options->hostbased_uses_name_from_packet_only == -1) options->hostbased_uses_name_from_packet_only = 0; if (options->rsa_authentication == -1) options->rsa_authentication = 1; if (options->pubkey_authentication == -1) options->pubkey_authentication = 1; if (options->kerberos_authentication == -1) options->kerberos_authentication = 0; if (options->kerberos_or_local_passwd == -1) options->kerberos_or_local_passwd = 1; if (options->kerberos_ticket_cleanup == -1) options->kerberos_ticket_cleanup = 1; if (options->kerberos_get_afs_token == -1) options->kerberos_get_afs_token = 0; if (options->gss_authentication == -1) options->gss_authentication = 0; if (options->gss_cleanup_creds == -1) options->gss_cleanup_creds = 1; if (options->gss_strict_acceptor == -1) options->gss_strict_acceptor = 0; if (options->password_authentication == -1) options->password_authentication = 0; if (options->kbd_interactive_authentication == -1) options->kbd_interactive_authentication = 0; if (options->challenge_response_authentication == -1) options->challenge_response_authentication = 1; if (options->permit_empty_passwd == -1) options->permit_empty_passwd = 0; if (options->permit_user_env == -1) options->permit_user_env = 0; if (options->use_login == -1) options->use_login = 0; if (options->compression == -1) options->compression = COMP_DELAYED; if (options->rekey_limit == -1) options->rekey_limit = 0; if (options->rekey_interval == -1) options->rekey_interval = 0; if (options->allow_tcp_forwarding == -1) options->allow_tcp_forwarding = FORWARD_ALLOW; if (options->allow_streamlocal_forwarding == -1) options->allow_streamlocal_forwarding = FORWARD_ALLOW; if (options->allow_agent_forwarding == -1) options->allow_agent_forwarding = 1; if (options->fwd_opts.gateway_ports == -1) options->fwd_opts.gateway_ports = 0; if (options->max_startups == -1) options->max_startups = 100; if (options->max_startups_rate == -1) options->max_startups_rate = 30; /* 30% */ if (options->max_startups_begin == -1) options->max_startups_begin = 10; if (options->max_authtries == -1) options->max_authtries = DEFAULT_AUTH_FAIL_MAX; if (options->max_sessions == -1) options->max_sessions = DEFAULT_SESSIONS_MAX; if (options->use_dns == -1) options->use_dns = 1; if (options->client_alive_interval == -1) options->client_alive_interval = 0; if (options->client_alive_count_max == -1) options->client_alive_count_max = 3; if (options->num_authkeys_files == 0) { options->authorized_keys_files[options->num_authkeys_files++] = xstrdup(_PATH_SSH_USER_PERMITTED_KEYS); options->authorized_keys_files[options->num_authkeys_files++] = xstrdup(_PATH_SSH_USER_PERMITTED_KEYS2); } if (options->permit_tun == -1) options->permit_tun = SSH_TUNMODE_NO; if (options->ip_qos_interactive == -1) options->ip_qos_interactive = IPTOS_LOWDELAY; if (options->ip_qos_bulk == -1) options->ip_qos_bulk = IPTOS_THROUGHPUT; if (options->version_addendum == NULL) options->version_addendum = xstrdup(SSH_VERSION_FREEBSD); if (options->fwd_opts.streamlocal_bind_mask == (mode_t)-1) options->fwd_opts.streamlocal_bind_mask = 0177; if (options->fwd_opts.streamlocal_bind_unlink == -1) options->fwd_opts.streamlocal_bind_unlink = 0; if (options->fingerprint_hash == -1) options->fingerprint_hash = SSH_FP_HASH_DEFAULT; + if (options->use_blacklist == -1) + options->use_blacklist = 0; assemble_algorithms(options); /* Turn privilege separation and sandboxing on by default */ if (use_privsep == -1) use_privsep = PRIVSEP_ON; #define CLEAR_ON_NONE(v) \ do { \ if (option_clear_or_none(v)) { \ free(v); \ v = NULL; \ } \ } while(0) CLEAR_ON_NONE(options->pid_file); CLEAR_ON_NONE(options->xauth_location); CLEAR_ON_NONE(options->banner); CLEAR_ON_NONE(options->trusted_user_ca_keys); CLEAR_ON_NONE(options->revoked_keys_file); CLEAR_ON_NONE(options->authorized_principals_file); CLEAR_ON_NONE(options->adm_forced_command); CLEAR_ON_NONE(options->chroot_directory); for (i = 0; i < options->num_host_key_files; i++) CLEAR_ON_NONE(options->host_key_files[i]); for (i = 0; i < options->num_host_cert_files; i++) CLEAR_ON_NONE(options->host_cert_files[i]); #undef CLEAR_ON_NONE #ifndef HAVE_MMAP if (use_privsep && options->compression == 1) { error("This platform does not support both privilege " "separation and compression"); error("Compression disabled"); options->compression = 0; } #endif } /* Keyword tokens. */ typedef enum { sBadOption, /* == unknown option */ /* Portable-specific options */ sUsePAM, /* Standard Options */ sPort, sHostKeyFile, sServerKeyBits, sLoginGraceTime, sKeyRegenerationTime, sPermitRootLogin, sLogFacility, sLogLevel, sRhostsRSAAuthentication, sRSAAuthentication, sKerberosAuthentication, sKerberosOrLocalPasswd, sKerberosTicketCleanup, sKerberosGetAFSToken, sKerberosTgtPassing, sChallengeResponseAuthentication, sPasswordAuthentication, sKbdInteractiveAuthentication, sListenAddress, sAddressFamily, sPrintMotd, sPrintLastLog, sIgnoreRhosts, sX11Forwarding, sX11DisplayOffset, sX11UseLocalhost, sPermitTTY, sStrictModes, sEmptyPasswd, sTCPKeepAlive, sPermitUserEnvironment, sUseLogin, sAllowTcpForwarding, sCompression, sRekeyLimit, sAllowUsers, sDenyUsers, sAllowGroups, sDenyGroups, sIgnoreUserKnownHosts, sCiphers, sMacs, sProtocol, sPidFile, sGatewayPorts, sPubkeyAuthentication, sPubkeyAcceptedKeyTypes, sXAuthLocation, sSubsystem, sMaxStartups, sMaxAuthTries, sMaxSessions, sBanner, sUseDNS, sHostbasedAuthentication, sHostbasedUsesNameFromPacketOnly, sHostbasedAcceptedKeyTypes, sHostKeyAlgorithms, sClientAliveInterval, sClientAliveCountMax, sAuthorizedKeysFile, sGssAuthentication, sGssCleanupCreds, sGssStrictAcceptor, sAcceptEnv, sPermitTunnel, sMatch, sPermitOpen, sForceCommand, sChrootDirectory, sUsePrivilegeSeparation, sAllowAgentForwarding, sHostCertificate, sRevokedKeys, sTrustedUserCAKeys, sAuthorizedPrincipalsFile, sAuthorizedPrincipalsCommand, sAuthorizedPrincipalsCommandUser, sKexAlgorithms, sIPQoS, sVersionAddendum, sAuthorizedKeysCommand, sAuthorizedKeysCommandUser, sAuthenticationMethods, sHostKeyAgent, sPermitUserRC, sStreamLocalBindMask, sStreamLocalBindUnlink, sAllowStreamLocalForwarding, sFingerprintHash, + sUseBlacklist, sDeprecated, sUnsupported } ServerOpCodes; #define SSHCFG_GLOBAL 0x01 /* allowed in main section of sshd_config */ #define SSHCFG_MATCH 0x02 /* allowed inside a Match section */ #define SSHCFG_ALL (SSHCFG_GLOBAL|SSHCFG_MATCH) /* Textual representation of the tokens. */ static struct { const char *name; ServerOpCodes opcode; u_int flags; } keywords[] = { /* Portable-specific options */ #ifdef USE_PAM { "usepam", sUsePAM, SSHCFG_GLOBAL }, #else { "usepam", sUnsupported, SSHCFG_GLOBAL }, #endif { "pamauthenticationviakbdint", sDeprecated, SSHCFG_GLOBAL }, /* Standard Options */ { "port", sPort, SSHCFG_GLOBAL }, { "hostkey", sHostKeyFile, SSHCFG_GLOBAL }, { "hostdsakey", sHostKeyFile, SSHCFG_GLOBAL }, /* alias */ { "hostkeyagent", sHostKeyAgent, SSHCFG_GLOBAL }, { "pidfile", sPidFile, SSHCFG_GLOBAL }, { "serverkeybits", sServerKeyBits, SSHCFG_GLOBAL }, { "logingracetime", sLoginGraceTime, SSHCFG_GLOBAL }, { "keyregenerationinterval", sKeyRegenerationTime, SSHCFG_GLOBAL }, { "permitrootlogin", sPermitRootLogin, SSHCFG_ALL }, { "syslogfacility", sLogFacility, SSHCFG_GLOBAL }, { "loglevel", sLogLevel, SSHCFG_GLOBAL }, { "rhostsauthentication", sDeprecated, SSHCFG_GLOBAL }, { "rhostsrsaauthentication", sRhostsRSAAuthentication, SSHCFG_ALL }, { "hostbasedauthentication", sHostbasedAuthentication, SSHCFG_ALL }, { "hostbasedusesnamefrompacketonly", sHostbasedUsesNameFromPacketOnly, SSHCFG_ALL }, { "hostbasedacceptedkeytypes", sHostbasedAcceptedKeyTypes, SSHCFG_ALL }, { "hostkeyalgorithms", sHostKeyAlgorithms, SSHCFG_GLOBAL }, { "rsaauthentication", sRSAAuthentication, SSHCFG_ALL }, { "pubkeyauthentication", sPubkeyAuthentication, SSHCFG_ALL }, { "pubkeyacceptedkeytypes", sPubkeyAcceptedKeyTypes, SSHCFG_ALL }, { "dsaauthentication", sPubkeyAuthentication, SSHCFG_GLOBAL }, /* alias */ #ifdef KRB5 { "kerberosauthentication", sKerberosAuthentication, SSHCFG_ALL }, { "kerberosorlocalpasswd", sKerberosOrLocalPasswd, SSHCFG_GLOBAL }, { "kerberosticketcleanup", sKerberosTicketCleanup, SSHCFG_GLOBAL }, #ifdef USE_AFS { "kerberosgetafstoken", sKerberosGetAFSToken, SSHCFG_GLOBAL }, #else { "kerberosgetafstoken", sUnsupported, SSHCFG_GLOBAL }, #endif #else { "kerberosauthentication", sUnsupported, SSHCFG_ALL }, { "kerberosorlocalpasswd", sUnsupported, SSHCFG_GLOBAL }, { "kerberosticketcleanup", sUnsupported, SSHCFG_GLOBAL }, { "kerberosgetafstoken", sUnsupported, SSHCFG_GLOBAL }, #endif { "kerberostgtpassing", sUnsupported, SSHCFG_GLOBAL }, { "afstokenpassing", sUnsupported, SSHCFG_GLOBAL }, #ifdef GSSAPI { "gssapiauthentication", sGssAuthentication, SSHCFG_ALL }, { "gssapicleanupcredentials", sGssCleanupCreds, SSHCFG_GLOBAL }, { "gssapistrictacceptorcheck", sGssStrictAcceptor, SSHCFG_GLOBAL }, #else { "gssapiauthentication", sUnsupported, SSHCFG_ALL }, { "gssapicleanupcredentials", sUnsupported, SSHCFG_GLOBAL }, { "gssapistrictacceptorcheck", sUnsupported, SSHCFG_GLOBAL }, #endif { "passwordauthentication", sPasswordAuthentication, SSHCFG_ALL }, { "kbdinteractiveauthentication", sKbdInteractiveAuthentication, SSHCFG_ALL }, { "challengeresponseauthentication", sChallengeResponseAuthentication, SSHCFG_GLOBAL }, { "skeyauthentication", sChallengeResponseAuthentication, SSHCFG_GLOBAL }, /* alias */ { "checkmail", sDeprecated, SSHCFG_GLOBAL }, { "listenaddress", sListenAddress, SSHCFG_GLOBAL }, { "addressfamily", sAddressFamily, SSHCFG_GLOBAL }, { "printmotd", sPrintMotd, SSHCFG_GLOBAL }, #ifdef DISABLE_LASTLOG { "printlastlog", sUnsupported, SSHCFG_GLOBAL }, #else { "printlastlog", sPrintLastLog, SSHCFG_GLOBAL }, #endif { "ignorerhosts", sIgnoreRhosts, SSHCFG_GLOBAL }, { "ignoreuserknownhosts", sIgnoreUserKnownHosts, SSHCFG_GLOBAL }, { "x11forwarding", sX11Forwarding, SSHCFG_ALL }, { "x11displayoffset", sX11DisplayOffset, SSHCFG_ALL }, { "x11uselocalhost", sX11UseLocalhost, SSHCFG_ALL }, { "xauthlocation", sXAuthLocation, SSHCFG_GLOBAL }, { "strictmodes", sStrictModes, SSHCFG_GLOBAL }, { "permitemptypasswords", sEmptyPasswd, SSHCFG_ALL }, { "permituserenvironment", sPermitUserEnvironment, SSHCFG_GLOBAL }, { "uselogin", sUseLogin, SSHCFG_GLOBAL }, { "compression", sCompression, SSHCFG_GLOBAL }, { "rekeylimit", sRekeyLimit, SSHCFG_ALL }, { "tcpkeepalive", sTCPKeepAlive, SSHCFG_GLOBAL }, { "keepalive", sTCPKeepAlive, SSHCFG_GLOBAL }, /* obsolete alias */ { "allowtcpforwarding", sAllowTcpForwarding, SSHCFG_ALL }, { "allowagentforwarding", sAllowAgentForwarding, SSHCFG_ALL }, { "allowusers", sAllowUsers, SSHCFG_ALL }, { "denyusers", sDenyUsers, SSHCFG_ALL }, { "allowgroups", sAllowGroups, SSHCFG_ALL }, { "denygroups", sDenyGroups, SSHCFG_ALL }, { "ciphers", sCiphers, SSHCFG_GLOBAL }, { "macs", sMacs, SSHCFG_GLOBAL }, { "protocol", sProtocol, SSHCFG_GLOBAL }, { "gatewayports", sGatewayPorts, SSHCFG_ALL }, { "subsystem", sSubsystem, SSHCFG_GLOBAL }, { "maxstartups", sMaxStartups, SSHCFG_GLOBAL }, { "maxauthtries", sMaxAuthTries, SSHCFG_ALL }, { "maxsessions", sMaxSessions, SSHCFG_ALL }, { "banner", sBanner, SSHCFG_ALL }, { "usedns", sUseDNS, SSHCFG_GLOBAL }, { "verifyreversemapping", sDeprecated, SSHCFG_GLOBAL }, { "reversemappingcheck", sDeprecated, SSHCFG_GLOBAL }, { "clientaliveinterval", sClientAliveInterval, SSHCFG_GLOBAL }, { "clientalivecountmax", sClientAliveCountMax, SSHCFG_GLOBAL }, { "authorizedkeysfile", sAuthorizedKeysFile, SSHCFG_ALL }, { "authorizedkeysfile2", sDeprecated, SSHCFG_ALL }, { "useprivilegeseparation", sUsePrivilegeSeparation, SSHCFG_GLOBAL}, { "acceptenv", sAcceptEnv, SSHCFG_ALL }, { "permittunnel", sPermitTunnel, SSHCFG_ALL }, { "permittty", sPermitTTY, SSHCFG_ALL }, { "permituserrc", sPermitUserRC, SSHCFG_ALL }, { "match", sMatch, SSHCFG_ALL }, { "permitopen", sPermitOpen, SSHCFG_ALL }, { "forcecommand", sForceCommand, SSHCFG_ALL }, { "chrootdirectory", sChrootDirectory, SSHCFG_ALL }, { "hostcertificate", sHostCertificate, SSHCFG_GLOBAL }, { "revokedkeys", sRevokedKeys, SSHCFG_ALL }, { "trustedusercakeys", sTrustedUserCAKeys, SSHCFG_ALL }, { "authorizedprincipalsfile", sAuthorizedPrincipalsFile, SSHCFG_ALL }, { "kexalgorithms", sKexAlgorithms, SSHCFG_GLOBAL }, { "ipqos", sIPQoS, SSHCFG_ALL }, { "authorizedkeyscommand", sAuthorizedKeysCommand, SSHCFG_ALL }, { "authorizedkeyscommanduser", sAuthorizedKeysCommandUser, SSHCFG_ALL }, { "authorizedprincipalscommand", sAuthorizedPrincipalsCommand, SSHCFG_ALL }, { "authorizedprincipalscommanduser", sAuthorizedPrincipalsCommandUser, SSHCFG_ALL }, { "versionaddendum", sVersionAddendum, SSHCFG_GLOBAL }, { "authenticationmethods", sAuthenticationMethods, SSHCFG_ALL }, { "streamlocalbindmask", sStreamLocalBindMask, SSHCFG_ALL }, { "streamlocalbindunlink", sStreamLocalBindUnlink, SSHCFG_ALL }, { "allowstreamlocalforwarding", sAllowStreamLocalForwarding, SSHCFG_ALL }, { "fingerprinthash", sFingerprintHash, SSHCFG_GLOBAL }, + { "useblacklist", sUseBlacklist, SSHCFG_GLOBAL }, { "noneenabled", sUnsupported, SSHCFG_ALL }, { "hpndisabled", sDeprecated, SSHCFG_ALL }, { "hpnbuffersize", sDeprecated, SSHCFG_ALL }, { "tcprcvbufpoll", sDeprecated, SSHCFG_ALL }, { NULL, sBadOption, 0 } }; static struct { int val; char *text; } tunmode_desc[] = { { SSH_TUNMODE_NO, "no" }, { SSH_TUNMODE_POINTOPOINT, "point-to-point" }, { SSH_TUNMODE_ETHERNET, "ethernet" }, { SSH_TUNMODE_YES, "yes" }, { -1, NULL } }; /* * Returns the number of the token pointed to by cp or sBadOption. */ static ServerOpCodes parse_token(const char *cp, const char *filename, int linenum, u_int *flags) { u_int i; for (i = 0; keywords[i].name; i++) if (strcasecmp(cp, keywords[i].name) == 0) { *flags = keywords[i].flags; return keywords[i].opcode; } error("%s: line %d: Bad configuration option: %s", filename, linenum, cp); return sBadOption; } char * derelativise_path(const char *path) { char *expanded, *ret, cwd[PATH_MAX]; if (strcasecmp(path, "none") == 0) return xstrdup("none"); expanded = tilde_expand_filename(path, getuid()); if (*expanded == '/') return expanded; if (getcwd(cwd, sizeof(cwd)) == NULL) fatal("%s: getcwd: %s", __func__, strerror(errno)); xasprintf(&ret, "%s/%s", cwd, expanded); free(expanded); return ret; } static void add_listen_addr(ServerOptions *options, char *addr, int port) { u_int i; if (port == 0) for (i = 0; i < options->num_ports; i++) add_one_listen_addr(options, addr, options->ports[i]); else add_one_listen_addr(options, addr, port); } static void add_one_listen_addr(ServerOptions *options, char *addr, int port) { struct addrinfo hints, *ai, *aitop; char strport[NI_MAXSERV]; int gaierr; memset(&hints, 0, sizeof(hints)); hints.ai_family = options->address_family; hints.ai_socktype = SOCK_STREAM; hints.ai_flags = (addr == NULL) ? AI_PASSIVE : 0; snprintf(strport, sizeof strport, "%d", port); if ((gaierr = getaddrinfo(addr, strport, &hints, &aitop)) != 0) fatal("bad addr or host: %s (%s)", addr ? addr : "", ssh_gai_strerror(gaierr)); for (ai = aitop; ai->ai_next; ai = ai->ai_next) ; ai->ai_next = options->listen_addrs; options->listen_addrs = aitop; } /* * Queue a ListenAddress to be processed once we have all of the Ports * and AddressFamily options. */ static void queue_listen_addr(ServerOptions *options, char *addr, int port) { options->queued_listen_addrs = xreallocarray( options->queued_listen_addrs, options->num_queued_listens + 1, sizeof(addr)); options->queued_listen_ports = xreallocarray( options->queued_listen_ports, options->num_queued_listens + 1, sizeof(port)); options->queued_listen_addrs[options->num_queued_listens] = xstrdup(addr); options->queued_listen_ports[options->num_queued_listens] = port; options->num_queued_listens++; } /* * Process queued (text) ListenAddress entries. */ static void process_queued_listen_addrs(ServerOptions *options) { u_int i; if (options->num_ports == 0) options->ports[options->num_ports++] = SSH_DEFAULT_PORT; if (options->address_family == -1) options->address_family = AF_UNSPEC; for (i = 0; i < options->num_queued_listens; i++) { add_listen_addr(options, options->queued_listen_addrs[i], options->queued_listen_ports[i]); free(options->queued_listen_addrs[i]); options->queued_listen_addrs[i] = NULL; } free(options->queued_listen_addrs); options->queued_listen_addrs = NULL; free(options->queued_listen_ports); options->queued_listen_ports = NULL; options->num_queued_listens = 0; } struct connection_info * get_connection_info(int populate, int use_dns) { static struct connection_info ci; if (!populate) return &ci; ci.host = get_canonical_hostname(use_dns); ci.address = get_remote_ipaddr(); ci.laddress = get_local_ipaddr(packet_get_connection_in()); ci.lport = get_local_port(); return &ci; } /* * The strategy for the Match blocks is that the config file is parsed twice. * * The first time is at startup. activep is initialized to 1 and the * directives in the global context are processed and acted on. Hitting a * Match directive unsets activep and the directives inside the block are * checked for syntax only. * * The second time is after a connection has been established but before * authentication. activep is initialized to 2 and global config directives * are ignored since they have already been processed. If the criteria in a * Match block is met, activep is set and the subsequent directives * processed and actioned until EOF or another Match block unsets it. Any * options set are copied into the main server config. * * Potential additions/improvements: * - Add Match support for pre-kex directives, eg Protocol, Ciphers. * * - Add a Tag directive (idea from David Leonard) ala pf, eg: * Match Address 192.168.0.* * Tag trusted * Match Group wheel * Tag trusted * Match Tag trusted * AllowTcpForwarding yes * GatewayPorts clientspecified * [...] * * - Add a PermittedChannelRequests directive * Match Group shell * PermittedChannelRequests session,forwarded-tcpip */ static int match_cfg_line_group(const char *grps, int line, const char *user) { int result = 0; struct passwd *pw; if (user == NULL) goto out; if ((pw = getpwnam(user)) == NULL) { debug("Can't match group at line %d because user %.100s does " "not exist", line, user); } else if (ga_init(pw->pw_name, pw->pw_gid) == 0) { debug("Can't Match group because user %.100s not in any group " "at line %d", user, line); } else if (ga_match_pattern_list(grps) != 1) { debug("user %.100s does not match group list %.100s at line %d", user, grps, line); } else { debug("user %.100s matched group list %.100s at line %d", user, grps, line); result = 1; } out: ga_free(); return result; } /* * All of the attributes on a single Match line are ANDed together, so we need * to check every attribute and set the result to zero if any attribute does * not match. */ static int match_cfg_line(char **condition, int line, struct connection_info *ci) { int result = 1, attributes = 0, port; char *arg, *attrib, *cp = *condition; if (ci == NULL) debug3("checking syntax for 'Match %s'", cp); else debug3("checking match for '%s' user %s host %s addr %s " "laddr %s lport %d", cp, ci->user ? ci->user : "(null)", ci->host ? ci->host : "(null)", ci->address ? ci->address : "(null)", ci->laddress ? ci->laddress : "(null)", ci->lport); while ((attrib = strdelim(&cp)) && *attrib != '\0') { attributes++; if (strcasecmp(attrib, "all") == 0) { if (attributes != 1 || ((arg = strdelim(&cp)) != NULL && *arg != '\0')) { error("'all' cannot be combined with other " "Match attributes"); return -1; } *condition = cp; return 1; } if ((arg = strdelim(&cp)) == NULL || *arg == '\0') { error("Missing Match criteria for %s", attrib); return -1; } if (strcasecmp(attrib, "user") == 0) { if (ci == NULL || ci->user == NULL) { result = 0; continue; } if (match_pattern_list(ci->user, arg, 0) != 1) result = 0; else debug("user %.100s matched 'User %.100s' at " "line %d", ci->user, arg, line); } else if (strcasecmp(attrib, "group") == 0) { if (ci == NULL || ci->user == NULL) { result = 0; continue; } switch (match_cfg_line_group(arg, line, ci->user)) { case -1: return -1; case 0: result = 0; } } else if (strcasecmp(attrib, "host") == 0) { if (ci == NULL || ci->host == NULL) { result = 0; continue; } if (match_hostname(ci->host, arg) != 1) result = 0; else debug("connection from %.100s matched 'Host " "%.100s' at line %d", ci->host, arg, line); } else if (strcasecmp(attrib, "address") == 0) { if (ci == NULL || ci->address == NULL) { result = 0; continue; } switch (addr_match_list(ci->address, arg)) { case 1: debug("connection from %.100s matched 'Address " "%.100s' at line %d", ci->address, arg, line); break; case 0: case -1: result = 0; break; case -2: return -1; } } else if (strcasecmp(attrib, "localaddress") == 0){ if (ci == NULL || ci->laddress == NULL) { result = 0; continue; } switch (addr_match_list(ci->laddress, arg)) { case 1: debug("connection from %.100s matched " "'LocalAddress %.100s' at line %d", ci->laddress, arg, line); break; case 0: case -1: result = 0; break; case -2: return -1; } } else if (strcasecmp(attrib, "localport") == 0) { if ((port = a2port(arg)) == -1) { error("Invalid LocalPort '%s' on Match line", arg); return -1; } if (ci == NULL || ci->lport == 0) { result = 0; continue; } /* TODO support port lists */ if (port == ci->lport) debug("connection from %.100s matched " "'LocalPort %d' at line %d", ci->laddress, port, line); else result = 0; } else { error("Unsupported Match attribute %s", attrib); return -1; } } if (attributes == 0) { error("One or more attributes required for Match"); return -1; } if (ci != NULL) debug3("match %sfound", result ? "" : "not "); *condition = cp; return result; } #define WHITESPACE " \t\r\n" /* Multistate option parsing */ struct multistate { char *key; int value; }; static const struct multistate multistate_addressfamily[] = { { "inet", AF_INET }, { "inet6", AF_INET6 }, { "any", AF_UNSPEC }, { NULL, -1 } }; static const struct multistate multistate_permitrootlogin[] = { { "without-password", PERMIT_NO_PASSWD }, { "prohibit-password", PERMIT_NO_PASSWD }, { "forced-commands-only", PERMIT_FORCED_ONLY }, { "yes", PERMIT_YES }, { "no", PERMIT_NO }, { NULL, -1 } }; static const struct multistate multistate_compression[] = { { "delayed", COMP_DELAYED }, { "yes", COMP_ZLIB }, { "no", COMP_NONE }, { NULL, -1 } }; static const struct multistate multistate_gatewayports[] = { { "clientspecified", 2 }, { "yes", 1 }, { "no", 0 }, { NULL, -1 } }; static const struct multistate multistate_privsep[] = { { "yes", PRIVSEP_NOSANDBOX }, { "sandbox", PRIVSEP_ON }, { "nosandbox", PRIVSEP_NOSANDBOX }, { "no", PRIVSEP_OFF }, { NULL, -1 } }; static const struct multistate multistate_tcpfwd[] = { { "yes", FORWARD_ALLOW }, { "all", FORWARD_ALLOW }, { "no", FORWARD_DENY }, { "remote", FORWARD_REMOTE }, { "local", FORWARD_LOCAL }, { NULL, -1 } }; int process_server_config_line(ServerOptions *options, char *line, const char *filename, int linenum, int *activep, struct connection_info *connectinfo) { char *cp, **charptr, *arg, *p; int cmdline = 0, *intptr, value, value2, n, port; SyslogFacility *log_facility_ptr; LogLevel *log_level_ptr; ServerOpCodes opcode; u_int i, flags = 0; size_t len; long long val64; const struct multistate *multistate_ptr; cp = line; if ((arg = strdelim(&cp)) == NULL) return 0; /* Ignore leading whitespace */ if (*arg == '\0') arg = strdelim(&cp); if (!arg || !*arg || *arg == '#') return 0; intptr = NULL; charptr = NULL; opcode = parse_token(arg, filename, linenum, &flags); if (activep == NULL) { /* We are processing a command line directive */ cmdline = 1; activep = &cmdline; } if (*activep && opcode != sMatch) debug3("%s:%d setting %s %s", filename, linenum, arg, cp); if (*activep == 0 && !(flags & SSHCFG_MATCH)) { if (connectinfo == NULL) { fatal("%s line %d: Directive '%s' is not allowed " "within a Match block", filename, linenum, arg); } else { /* this is a directive we have already processed */ while (arg) arg = strdelim(&cp); return 0; } } switch (opcode) { /* Portable-specific options */ case sUsePAM: intptr = &options->use_pam; goto parse_flag; /* Standard Options */ case sBadOption: return -1; case sPort: /* ignore ports from configfile if cmdline specifies ports */ if (options->ports_from_cmdline) return 0; if (options->num_ports >= MAX_PORTS) fatal("%s line %d: too many ports.", filename, linenum); arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing port number.", filename, linenum); options->ports[options->num_ports++] = a2port(arg); if (options->ports[options->num_ports-1] <= 0) fatal("%s line %d: Badly formatted port number.", filename, linenum); break; case sServerKeyBits: intptr = &options->server_key_bits; parse_int: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing integer value.", filename, linenum); value = atoi(arg); if (*activep && *intptr == -1) *intptr = value; break; case sLoginGraceTime: intptr = &options->login_grace_time; parse_time: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing time value.", filename, linenum); if ((value = convtime(arg)) == -1) fatal("%s line %d: invalid time value.", filename, linenum); if (*activep && *intptr == -1) *intptr = value; break; case sKeyRegenerationTime: intptr = &options->key_regeneration_time; goto parse_time; case sListenAddress: arg = strdelim(&cp); if (arg == NULL || *arg == '\0') fatal("%s line %d: missing address", filename, linenum); /* check for bare IPv6 address: no "[]" and 2 or more ":" */ if (strchr(arg, '[') == NULL && (p = strchr(arg, ':')) != NULL && strchr(p+1, ':') != NULL) { queue_listen_addr(options, arg, 0); break; } p = hpdelim(&arg); if (p == NULL) fatal("%s line %d: bad address:port usage", filename, linenum); p = cleanhostname(p); if (arg == NULL) port = 0; else if ((port = a2port(arg)) <= 0) fatal("%s line %d: bad port number", filename, linenum); queue_listen_addr(options, p, port); break; case sAddressFamily: intptr = &options->address_family; multistate_ptr = multistate_addressfamily; parse_multistate: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing argument.", filename, linenum); value = -1; for (i = 0; multistate_ptr[i].key != NULL; i++) { if (strcasecmp(arg, multistate_ptr[i].key) == 0) { value = multistate_ptr[i].value; break; } } if (value == -1) fatal("%s line %d: unsupported option \"%s\".", filename, linenum, arg); if (*activep && *intptr == -1) *intptr = value; break; case sHostKeyFile: intptr = &options->num_host_key_files; if (*intptr >= MAX_HOSTKEYS) fatal("%s line %d: too many host keys specified (max %d).", filename, linenum, MAX_HOSTKEYS); charptr = &options->host_key_files[*intptr]; parse_filename: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing file name.", filename, linenum); if (*activep && *charptr == NULL) { *charptr = derelativise_path(arg); /* increase optional counter */ if (intptr != NULL) *intptr = *intptr + 1; } break; case sHostKeyAgent: charptr = &options->host_key_agent; arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing socket name.", filename, linenum); if (*activep && *charptr == NULL) *charptr = !strcmp(arg, SSH_AUTHSOCKET_ENV_NAME) ? xstrdup(arg) : derelativise_path(arg); break; case sHostCertificate: intptr = &options->num_host_cert_files; if (*intptr >= MAX_HOSTKEYS) fatal("%s line %d: too many host certificates " "specified (max %d).", filename, linenum, MAX_HOSTCERTS); charptr = &options->host_cert_files[*intptr]; goto parse_filename; break; case sPidFile: charptr = &options->pid_file; goto parse_filename; case sPermitRootLogin: intptr = &options->permit_root_login; multistate_ptr = multistate_permitrootlogin; goto parse_multistate; case sIgnoreRhosts: intptr = &options->ignore_rhosts; parse_flag: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing yes/no argument.", filename, linenum); value = 0; /* silence compiler */ if (strcmp(arg, "yes") == 0) value = 1; else if (strcmp(arg, "no") == 0) value = 0; else fatal("%s line %d: Bad yes/no argument: %s", filename, linenum, arg); if (*activep && *intptr == -1) *intptr = value; break; case sIgnoreUserKnownHosts: intptr = &options->ignore_user_known_hosts; goto parse_flag; case sRhostsRSAAuthentication: intptr = &options->rhosts_rsa_authentication; goto parse_flag; case sHostbasedAuthentication: intptr = &options->hostbased_authentication; goto parse_flag; case sHostbasedUsesNameFromPacketOnly: intptr = &options->hostbased_uses_name_from_packet_only; goto parse_flag; case sHostbasedAcceptedKeyTypes: charptr = &options->hostbased_key_types; parse_keytypes: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing argument.", filename, linenum); if (!sshkey_names_valid2(*arg == '+' ? arg + 1 : arg, 1)) fatal("%s line %d: Bad key types '%s'.", filename, linenum, arg ? arg : ""); if (*activep && *charptr == NULL) *charptr = xstrdup(arg); break; case sHostKeyAlgorithms: charptr = &options->hostkeyalgorithms; goto parse_keytypes; case sRSAAuthentication: intptr = &options->rsa_authentication; goto parse_flag; case sPubkeyAuthentication: intptr = &options->pubkey_authentication; goto parse_flag; case sPubkeyAcceptedKeyTypes: charptr = &options->pubkey_key_types; goto parse_keytypes; case sKerberosAuthentication: intptr = &options->kerberos_authentication; goto parse_flag; case sKerberosOrLocalPasswd: intptr = &options->kerberos_or_local_passwd; goto parse_flag; case sKerberosTicketCleanup: intptr = &options->kerberos_ticket_cleanup; goto parse_flag; case sKerberosGetAFSToken: intptr = &options->kerberos_get_afs_token; goto parse_flag; case sGssAuthentication: intptr = &options->gss_authentication; goto parse_flag; case sGssCleanupCreds: intptr = &options->gss_cleanup_creds; goto parse_flag; case sGssStrictAcceptor: intptr = &options->gss_strict_acceptor; goto parse_flag; case sPasswordAuthentication: intptr = &options->password_authentication; goto parse_flag; case sKbdInteractiveAuthentication: intptr = &options->kbd_interactive_authentication; goto parse_flag; case sChallengeResponseAuthentication: intptr = &options->challenge_response_authentication; goto parse_flag; case sPrintMotd: intptr = &options->print_motd; goto parse_flag; case sPrintLastLog: intptr = &options->print_lastlog; goto parse_flag; case sX11Forwarding: intptr = &options->x11_forwarding; goto parse_flag; case sX11DisplayOffset: intptr = &options->x11_display_offset; goto parse_int; case sX11UseLocalhost: intptr = &options->x11_use_localhost; goto parse_flag; case sXAuthLocation: charptr = &options->xauth_location; goto parse_filename; case sPermitTTY: intptr = &options->permit_tty; goto parse_flag; case sPermitUserRC: intptr = &options->permit_user_rc; goto parse_flag; case sStrictModes: intptr = &options->strict_modes; goto parse_flag; case sTCPKeepAlive: intptr = &options->tcp_keep_alive; goto parse_flag; case sEmptyPasswd: intptr = &options->permit_empty_passwd; goto parse_flag; case sPermitUserEnvironment: intptr = &options->permit_user_env; goto parse_flag; case sUseLogin: intptr = &options->use_login; goto parse_flag; case sCompression: intptr = &options->compression; multistate_ptr = multistate_compression; goto parse_multistate; case sRekeyLimit: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); if (strcmp(arg, "default") == 0) { val64 = 0; } else { if (scan_scaled(arg, &val64) == -1) fatal("%.200s line %d: Bad number '%s': %s", filename, linenum, arg, strerror(errno)); if (val64 != 0 && val64 < 16) fatal("%.200s line %d: RekeyLimit too small", filename, linenum); } if (*activep && options->rekey_limit == -1) options->rekey_limit = val64; if (cp != NULL) { /* optional rekey interval present */ if (strcmp(cp, "none") == 0) { (void)strdelim(&cp); /* discard */ break; } intptr = &options->rekey_interval; goto parse_time; } break; case sGatewayPorts: intptr = &options->fwd_opts.gateway_ports; multistate_ptr = multistate_gatewayports; goto parse_multistate; case sUseDNS: intptr = &options->use_dns; goto parse_flag; case sLogFacility: log_facility_ptr = &options->log_facility; arg = strdelim(&cp); value = log_facility_number(arg); if (value == SYSLOG_FACILITY_NOT_SET) fatal("%.200s line %d: unsupported log facility '%s'", filename, linenum, arg ? arg : ""); if (*log_facility_ptr == -1) *log_facility_ptr = (SyslogFacility) value; break; case sLogLevel: log_level_ptr = &options->log_level; arg = strdelim(&cp); value = log_level_number(arg); if (value == SYSLOG_LEVEL_NOT_SET) fatal("%.200s line %d: unsupported log level '%s'", filename, linenum, arg ? arg : ""); if (*log_level_ptr == -1) *log_level_ptr = (LogLevel) value; break; case sAllowTcpForwarding: intptr = &options->allow_tcp_forwarding; multistate_ptr = multistate_tcpfwd; goto parse_multistate; case sAllowStreamLocalForwarding: intptr = &options->allow_streamlocal_forwarding; multistate_ptr = multistate_tcpfwd; goto parse_multistate; case sAllowAgentForwarding: intptr = &options->allow_agent_forwarding; goto parse_flag; case sUsePrivilegeSeparation: intptr = &use_privsep; multistate_ptr = multistate_privsep; goto parse_multistate; case sAllowUsers: while ((arg = strdelim(&cp)) && *arg != '\0') { if (options->num_allow_users >= MAX_ALLOW_USERS) fatal("%s line %d: too many allow users.", filename, linenum); if (!*activep) continue; options->allow_users[options->num_allow_users++] = xstrdup(arg); } break; case sDenyUsers: while ((arg = strdelim(&cp)) && *arg != '\0') { if (options->num_deny_users >= MAX_DENY_USERS) fatal("%s line %d: too many deny users.", filename, linenum); if (!*activep) continue; options->deny_users[options->num_deny_users++] = xstrdup(arg); } break; case sAllowGroups: while ((arg = strdelim(&cp)) && *arg != '\0') { if (options->num_allow_groups >= MAX_ALLOW_GROUPS) fatal("%s line %d: too many allow groups.", filename, linenum); if (!*activep) continue; options->allow_groups[options->num_allow_groups++] = xstrdup(arg); } break; case sDenyGroups: while ((arg = strdelim(&cp)) && *arg != '\0') { if (options->num_deny_groups >= MAX_DENY_GROUPS) fatal("%s line %d: too many deny groups.", filename, linenum); if (!*activep) continue; options->deny_groups[options->num_deny_groups++] = xstrdup(arg); } break; case sCiphers: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing argument.", filename, linenum); if (!ciphers_valid(*arg == '+' ? arg + 1 : arg)) fatal("%s line %d: Bad SSH2 cipher spec '%s'.", filename, linenum, arg ? arg : ""); if (options->ciphers == NULL) options->ciphers = xstrdup(arg); break; case sMacs: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing argument.", filename, linenum); if (!mac_valid(*arg == '+' ? arg + 1 : arg)) fatal("%s line %d: Bad SSH2 mac spec '%s'.", filename, linenum, arg ? arg : ""); if (options->macs == NULL) options->macs = xstrdup(arg); break; case sKexAlgorithms: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing argument.", filename, linenum); if (!kex_names_valid(*arg == '+' ? arg + 1 : arg)) fatal("%s line %d: Bad SSH2 KexAlgorithms '%s'.", filename, linenum, arg ? arg : ""); if (options->kex_algorithms == NULL) options->kex_algorithms = xstrdup(arg); break; case sProtocol: intptr = &options->protocol; arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing argument.", filename, linenum); value = proto_spec(arg); if (value == SSH_PROTO_UNKNOWN) fatal("%s line %d: Bad protocol spec '%s'.", filename, linenum, arg ? arg : ""); if (*intptr == SSH_PROTO_UNKNOWN) *intptr = value; break; case sSubsystem: if (options->num_subsystems >= MAX_SUBSYSTEMS) { fatal("%s line %d: too many subsystems defined.", filename, linenum); } arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing subsystem name.", filename, linenum); if (!*activep) { arg = strdelim(&cp); break; } for (i = 0; i < options->num_subsystems; i++) if (strcmp(arg, options->subsystem_name[i]) == 0) fatal("%s line %d: Subsystem '%s' already defined.", filename, linenum, arg); options->subsystem_name[options->num_subsystems] = xstrdup(arg); arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing subsystem command.", filename, linenum); options->subsystem_command[options->num_subsystems] = xstrdup(arg); /* Collect arguments (separate to executable) */ p = xstrdup(arg); len = strlen(p) + 1; while ((arg = strdelim(&cp)) != NULL && *arg != '\0') { len += 1 + strlen(arg); p = xreallocarray(p, 1, len); strlcat(p, " ", len); strlcat(p, arg, len); } options->subsystem_args[options->num_subsystems] = p; options->num_subsystems++; break; case sMaxStartups: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing MaxStartups spec.", filename, linenum); if ((n = sscanf(arg, "%d:%d:%d", &options->max_startups_begin, &options->max_startups_rate, &options->max_startups)) == 3) { if (options->max_startups_begin > options->max_startups || options->max_startups_rate > 100 || options->max_startups_rate < 1) fatal("%s line %d: Illegal MaxStartups spec.", filename, linenum); } else if (n != 1) fatal("%s line %d: Illegal MaxStartups spec.", filename, linenum); else options->max_startups = options->max_startups_begin; break; case sMaxAuthTries: intptr = &options->max_authtries; goto parse_int; case sMaxSessions: intptr = &options->max_sessions; goto parse_int; case sBanner: charptr = &options->banner; goto parse_filename; /* * These options can contain %X options expanded at * connect time, so that you can specify paths like: * * AuthorizedKeysFile /etc/ssh_keys/%u */ case sAuthorizedKeysFile: if (*activep && options->num_authkeys_files == 0) { while ((arg = strdelim(&cp)) && *arg != '\0') { if (options->num_authkeys_files >= MAX_AUTHKEYS_FILES) fatal("%s line %d: " "too many authorized keys files.", filename, linenum); options->authorized_keys_files[ options->num_authkeys_files++] = tilde_expand_filename(arg, getuid()); } } return 0; case sAuthorizedPrincipalsFile: charptr = &options->authorized_principals_file; arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing file name.", filename, linenum); if (*activep && *charptr == NULL) { *charptr = tilde_expand_filename(arg, getuid()); /* increase optional counter */ if (intptr != NULL) *intptr = *intptr + 1; } break; case sClientAliveInterval: intptr = &options->client_alive_interval; goto parse_time; case sClientAliveCountMax: intptr = &options->client_alive_count_max; goto parse_int; case sAcceptEnv: while ((arg = strdelim(&cp)) && *arg != '\0') { if (strchr(arg, '=') != NULL) fatal("%s line %d: Invalid environment name.", filename, linenum); if (options->num_accept_env >= MAX_ACCEPT_ENV) fatal("%s line %d: too many allow env.", filename, linenum); if (!*activep) continue; options->accept_env[options->num_accept_env++] = xstrdup(arg); } break; case sPermitTunnel: intptr = &options->permit_tun; arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: Missing yes/point-to-point/" "ethernet/no argument.", filename, linenum); value = -1; for (i = 0; tunmode_desc[i].val != -1; i++) if (strcmp(tunmode_desc[i].text, arg) == 0) { value = tunmode_desc[i].val; break; } if (value == -1) fatal("%s line %d: Bad yes/point-to-point/ethernet/" "no argument: %s", filename, linenum, arg); if (*activep && *intptr == -1) *intptr = value; break; case sMatch: if (cmdline) fatal("Match directive not supported as a command-line " "option"); value = match_cfg_line(&cp, linenum, connectinfo); if (value < 0) fatal("%s line %d: Bad Match condition", filename, linenum); *activep = value; break; case sPermitOpen: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing PermitOpen specification", filename, linenum); n = options->num_permitted_opens; /* modified later */ if (strcmp(arg, "any") == 0) { if (*activep && n == -1) { channel_clear_adm_permitted_opens(); options->num_permitted_opens = 0; } break; } if (strcmp(arg, "none") == 0) { if (*activep && n == -1) { options->num_permitted_opens = 1; channel_disable_adm_local_opens(); } break; } if (*activep && n == -1) channel_clear_adm_permitted_opens(); for (; arg != NULL && *arg != '\0'; arg = strdelim(&cp)) { p = hpdelim(&arg); if (p == NULL) fatal("%s line %d: missing host in PermitOpen", filename, linenum); p = cleanhostname(p); if (arg == NULL || ((port = permitopen_port(arg)) < 0)) fatal("%s line %d: bad port number in " "PermitOpen", filename, linenum); if (*activep && n == -1) options->num_permitted_opens = channel_add_adm_permitted_opens(p, port); } break; case sForceCommand: if (cp == NULL || *cp == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); len = strspn(cp, WHITESPACE); if (*activep && options->adm_forced_command == NULL) options->adm_forced_command = xstrdup(cp + len); return 0; case sChrootDirectory: charptr = &options->chroot_directory; arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing file name.", filename, linenum); if (*activep && *charptr == NULL) *charptr = xstrdup(arg); break; case sTrustedUserCAKeys: charptr = &options->trusted_user_ca_keys; goto parse_filename; case sRevokedKeys: charptr = &options->revoked_keys_file; goto parse_filename; case sIPQoS: arg = strdelim(&cp); if ((value = parse_ipqos(arg)) == -1) fatal("%s line %d: Bad IPQoS value: %s", filename, linenum, arg); arg = strdelim(&cp); if (arg == NULL) value2 = value; else if ((value2 = parse_ipqos(arg)) == -1) fatal("%s line %d: Bad IPQoS value: %s", filename, linenum, arg); if (*activep) { options->ip_qos_interactive = value; options->ip_qos_bulk = value2; } break; case sVersionAddendum: if (cp == NULL || *cp == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); len = strspn(cp, WHITESPACE); if (*activep && options->version_addendum == NULL) { if (strcasecmp(cp + len, "none") == 0) options->version_addendum = xstrdup(""); else if (strchr(cp + len, '\r') != NULL) fatal("%.200s line %d: Invalid argument", filename, linenum); else options->version_addendum = xstrdup(cp + len); } return 0; case sAuthorizedKeysCommand: if (cp == NULL) fatal("%.200s line %d: Missing argument.", filename, linenum); len = strspn(cp, WHITESPACE); if (*activep && options->authorized_keys_command == NULL) { if (cp[len] != '/' && strcasecmp(cp + len, "none") != 0) fatal("%.200s line %d: AuthorizedKeysCommand " "must be an absolute path", filename, linenum); options->authorized_keys_command = xstrdup(cp + len); } return 0; case sAuthorizedKeysCommandUser: charptr = &options->authorized_keys_command_user; arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing AuthorizedKeysCommandUser " "argument.", filename, linenum); if (*activep && *charptr == NULL) *charptr = xstrdup(arg); break; case sAuthorizedPrincipalsCommand: if (cp == NULL) fatal("%.200s line %d: Missing argument.", filename, linenum); len = strspn(cp, WHITESPACE); if (*activep && options->authorized_principals_command == NULL) { if (cp[len] != '/' && strcasecmp(cp + len, "none") != 0) fatal("%.200s line %d: " "AuthorizedPrincipalsCommand must be " "an absolute path", filename, linenum); options->authorized_principals_command = xstrdup(cp + len); } return 0; case sAuthorizedPrincipalsCommandUser: charptr = &options->authorized_principals_command_user; arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing " "AuthorizedPrincipalsCommandUser argument.", filename, linenum); if (*activep && *charptr == NULL) *charptr = xstrdup(arg); break; case sAuthenticationMethods: if (options->num_auth_methods == 0) { while ((arg = strdelim(&cp)) && *arg != '\0') { if (options->num_auth_methods >= MAX_AUTH_METHODS) fatal("%s line %d: " "too many authentication methods.", filename, linenum); if (auth2_methods_valid(arg, 0) != 0) fatal("%s line %d: invalid " "authentication method list.", filename, linenum); if (!*activep) continue; options->auth_methods[ options->num_auth_methods++] = xstrdup(arg); } } return 0; case sStreamLocalBindMask: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%s line %d: missing StreamLocalBindMask " "argument.", filename, linenum); /* Parse mode in octal format */ value = strtol(arg, &p, 8); if (arg == p || value < 0 || value > 0777) fatal("%s line %d: Bad mask.", filename, linenum); if (*activep) options->fwd_opts.streamlocal_bind_mask = (mode_t)value; break; case sStreamLocalBindUnlink: intptr = &options->fwd_opts.streamlocal_bind_unlink; goto parse_flag; case sFingerprintHash: arg = strdelim(&cp); if (!arg || *arg == '\0') fatal("%.200s line %d: Missing argument.", filename, linenum); if ((value = ssh_digest_alg_by_name(arg)) == -1) fatal("%.200s line %d: Invalid hash algorithm \"%s\".", filename, linenum, arg); if (*activep) options->fingerprint_hash = value; break; + case sUseBlacklist: + intptr = &options->use_blacklist; + goto parse_flag; + case sDeprecated: logit("%s line %d: Deprecated option %s", filename, linenum, arg); while (arg) arg = strdelim(&cp); break; case sUnsupported: logit("%s line %d: Unsupported option %s", filename, linenum, arg); while (arg) arg = strdelim(&cp); break; default: fatal("%s line %d: Missing handler for opcode %s (%d)", filename, linenum, arg, opcode); } if ((arg = strdelim(&cp)) != NULL && *arg != '\0') fatal("%s line %d: garbage at end of line; \"%.200s\".", filename, linenum, arg); return 0; } /* Reads the server configuration file. */ void load_server_config(const char *filename, Buffer *conf) { char line[4096], *cp; FILE *f; int lineno = 0; debug2("%s: filename %s", __func__, filename); if ((f = fopen(filename, "r")) == NULL) { perror(filename); exit(1); } buffer_clear(conf); while (fgets(line, sizeof(line), f)) { lineno++; if (strlen(line) == sizeof(line) - 1) fatal("%s line %d too long", filename, lineno); /* * Trim out comments and strip whitespace * NB - preserve newlines, they are needed to reproduce * line numbers later for error messages */ if ((cp = strchr(line, '#')) != NULL) memcpy(cp, "\n", 2); cp = line + strspn(line, " \t\r"); buffer_append(conf, cp, strlen(cp)); } buffer_append(conf, "\0", 1); fclose(f); debug2("%s: done config len = %d", __func__, buffer_len(conf)); } void parse_server_match_config(ServerOptions *options, struct connection_info *connectinfo) { ServerOptions mo; initialize_server_options(&mo); parse_server_config(&mo, "reprocess config", &cfg, connectinfo); copy_set_server_options(options, &mo, 0); } int parse_server_match_testspec(struct connection_info *ci, char *spec) { char *p; while ((p = strsep(&spec, ",")) && *p != '\0') { if (strncmp(p, "addr=", 5) == 0) { ci->address = xstrdup(p + 5); } else if (strncmp(p, "host=", 5) == 0) { ci->host = xstrdup(p + 5); } else if (strncmp(p, "user=", 5) == 0) { ci->user = xstrdup(p + 5); } else if (strncmp(p, "laddr=", 6) == 0) { ci->laddress = xstrdup(p + 6); } else if (strncmp(p, "lport=", 6) == 0) { ci->lport = a2port(p + 6); if (ci->lport == -1) { fprintf(stderr, "Invalid port '%s' in test mode" " specification %s\n", p+6, p); return -1; } } else { fprintf(stderr, "Invalid test mode specification %s\n", p); return -1; } } return 0; } /* * returns 1 for a complete spec, 0 for partial spec and -1 for an * empty spec. */ int server_match_spec_complete(struct connection_info *ci) { if (ci->user && ci->host && ci->address) return 1; /* complete */ if (!ci->user && !ci->host && !ci->address) return -1; /* empty */ return 0; /* partial */ } /* * Copy any supported values that are set. * * If the preauth flag is set, we do not bother copying the string or * array values that are not used pre-authentication, because any that we * do use must be explictly sent in mm_getpwnamallow(). */ void copy_set_server_options(ServerOptions *dst, ServerOptions *src, int preauth) { #define M_CP_INTOPT(n) do {\ if (src->n != -1) \ dst->n = src->n; \ } while (0) M_CP_INTOPT(password_authentication); M_CP_INTOPT(gss_authentication); M_CP_INTOPT(rsa_authentication); M_CP_INTOPT(pubkey_authentication); M_CP_INTOPT(kerberos_authentication); M_CP_INTOPT(hostbased_authentication); M_CP_INTOPT(hostbased_uses_name_from_packet_only); M_CP_INTOPT(kbd_interactive_authentication); M_CP_INTOPT(permit_root_login); M_CP_INTOPT(permit_empty_passwd); M_CP_INTOPT(allow_tcp_forwarding); M_CP_INTOPT(allow_streamlocal_forwarding); M_CP_INTOPT(allow_agent_forwarding); M_CP_INTOPT(permit_tun); M_CP_INTOPT(fwd_opts.gateway_ports); M_CP_INTOPT(x11_display_offset); M_CP_INTOPT(x11_forwarding); M_CP_INTOPT(x11_use_localhost); M_CP_INTOPT(permit_tty); M_CP_INTOPT(permit_user_rc); M_CP_INTOPT(max_sessions); M_CP_INTOPT(max_authtries); M_CP_INTOPT(ip_qos_interactive); M_CP_INTOPT(ip_qos_bulk); M_CP_INTOPT(rekey_limit); M_CP_INTOPT(rekey_interval); /* M_CP_STROPT and M_CP_STRARRAYOPT should not appear before here */ #define M_CP_STROPT(n) do {\ if (src->n != NULL && dst->n != src->n) { \ free(dst->n); \ dst->n = src->n; \ } \ } while(0) #define M_CP_STRARRAYOPT(n, num_n) do {\ if (src->num_n != 0) { \ for (dst->num_n = 0; dst->num_n < src->num_n; dst->num_n++) \ dst->n[dst->num_n] = xstrdup(src->n[dst->num_n]); \ } \ } while(0) /* See comment in servconf.h */ COPY_MATCH_STRING_OPTS(); /* Arguments that accept '+...' need to be expanded */ assemble_algorithms(dst); /* * The only things that should be below this point are string options * which are only used after authentication. */ if (preauth) return; /* These options may be "none" to clear a global setting */ M_CP_STROPT(adm_forced_command); if (option_clear_or_none(dst->adm_forced_command)) { free(dst->adm_forced_command); dst->adm_forced_command = NULL; } M_CP_STROPT(chroot_directory); if (option_clear_or_none(dst->chroot_directory)) { free(dst->chroot_directory); dst->chroot_directory = NULL; } } #undef M_CP_INTOPT #undef M_CP_STROPT #undef M_CP_STRARRAYOPT void parse_server_config(ServerOptions *options, const char *filename, Buffer *conf, struct connection_info *connectinfo) { int active, linenum, bad_options = 0; char *cp, *obuf, *cbuf; debug2("%s: config %s len %d", __func__, filename, buffer_len(conf)); obuf = cbuf = xstrdup(buffer_ptr(conf)); active = connectinfo ? 0 : 1; linenum = 1; while ((cp = strsep(&cbuf, "\n")) != NULL) { if (process_server_config_line(options, cp, filename, linenum++, &active, connectinfo) != 0) bad_options++; } free(obuf); if (bad_options > 0) fatal("%s: terminating, %d bad configuration options", filename, bad_options); process_queued_listen_addrs(options); } static const char * fmt_multistate_int(int val, const struct multistate *m) { u_int i; for (i = 0; m[i].key != NULL; i++) { if (m[i].value == val) return m[i].key; } return "UNKNOWN"; } static const char * fmt_intarg(ServerOpCodes code, int val) { if (val == -1) return "unset"; switch (code) { case sAddressFamily: return fmt_multistate_int(val, multistate_addressfamily); case sPermitRootLogin: return fmt_multistate_int(val, multistate_permitrootlogin); case sGatewayPorts: return fmt_multistate_int(val, multistate_gatewayports); case sCompression: return fmt_multistate_int(val, multistate_compression); case sUsePrivilegeSeparation: return fmt_multistate_int(val, multistate_privsep); case sAllowTcpForwarding: return fmt_multistate_int(val, multistate_tcpfwd); case sAllowStreamLocalForwarding: return fmt_multistate_int(val, multistate_tcpfwd); case sFingerprintHash: return ssh_digest_alg_name(val); case sProtocol: switch (val) { case SSH_PROTO_1: return "1"; case SSH_PROTO_2: return "2"; case (SSH_PROTO_1|SSH_PROTO_2): return "2,1"; default: return "UNKNOWN"; } default: switch (val) { case 0: return "no"; case 1: return "yes"; default: return "UNKNOWN"; } } } static const char * lookup_opcode_name(ServerOpCodes code) { u_int i; for (i = 0; keywords[i].name != NULL; i++) if (keywords[i].opcode == code) return(keywords[i].name); return "UNKNOWN"; } static void dump_cfg_int(ServerOpCodes code, int val) { printf("%s %d\n", lookup_opcode_name(code), val); } static void dump_cfg_oct(ServerOpCodes code, int val) { printf("%s 0%o\n", lookup_opcode_name(code), val); } static void dump_cfg_fmtint(ServerOpCodes code, int val) { printf("%s %s\n", lookup_opcode_name(code), fmt_intarg(code, val)); } static void dump_cfg_string(ServerOpCodes code, const char *val) { if (val == NULL) return; printf("%s %s\n", lookup_opcode_name(code), val == NULL ? "none" : val); } static void dump_cfg_strarray(ServerOpCodes code, u_int count, char **vals) { u_int i; for (i = 0; i < count; i++) printf("%s %s\n", lookup_opcode_name(code), vals[i]); } static void dump_cfg_strarray_oneline(ServerOpCodes code, u_int count, char **vals) { u_int i; if (count <= 0) return; printf("%s", lookup_opcode_name(code)); for (i = 0; i < count; i++) printf(" %s", vals[i]); printf("\n"); } void dump_config(ServerOptions *o) { u_int i; int ret; struct addrinfo *ai; char addr[NI_MAXHOST], port[NI_MAXSERV], *s = NULL; char *laddr1 = xstrdup(""), *laddr2 = NULL; /* these are usually at the top of the config */ for (i = 0; i < o->num_ports; i++) printf("port %d\n", o->ports[i]); dump_cfg_fmtint(sProtocol, o->protocol); dump_cfg_fmtint(sAddressFamily, o->address_family); /* * ListenAddress must be after Port. add_one_listen_addr pushes * addresses onto a stack, so to maintain ordering we need to * print these in reverse order. */ for (ai = o->listen_addrs; ai; ai = ai->ai_next) { if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), port, sizeof(port), NI_NUMERICHOST|NI_NUMERICSERV)) != 0) { error("getnameinfo failed: %.100s", (ret != EAI_SYSTEM) ? gai_strerror(ret) : strerror(errno)); } else { laddr2 = laddr1; if (ai->ai_family == AF_INET6) xasprintf(&laddr1, "listenaddress [%s]:%s\n%s", addr, port, laddr2); else xasprintf(&laddr1, "listenaddress %s:%s\n%s", addr, port, laddr2); free(laddr2); } } printf("%s", laddr1); free(laddr1); /* integer arguments */ #ifdef USE_PAM dump_cfg_fmtint(sUsePAM, o->use_pam); #endif dump_cfg_int(sServerKeyBits, o->server_key_bits); dump_cfg_int(sLoginGraceTime, o->login_grace_time); dump_cfg_int(sKeyRegenerationTime, o->key_regeneration_time); dump_cfg_int(sX11DisplayOffset, o->x11_display_offset); dump_cfg_int(sMaxAuthTries, o->max_authtries); dump_cfg_int(sMaxSessions, o->max_sessions); dump_cfg_int(sClientAliveInterval, o->client_alive_interval); dump_cfg_int(sClientAliveCountMax, o->client_alive_count_max); dump_cfg_oct(sStreamLocalBindMask, o->fwd_opts.streamlocal_bind_mask); /* formatted integer arguments */ dump_cfg_fmtint(sPermitRootLogin, o->permit_root_login); dump_cfg_fmtint(sIgnoreRhosts, o->ignore_rhosts); dump_cfg_fmtint(sIgnoreUserKnownHosts, o->ignore_user_known_hosts); dump_cfg_fmtint(sRhostsRSAAuthentication, o->rhosts_rsa_authentication); dump_cfg_fmtint(sHostbasedAuthentication, o->hostbased_authentication); dump_cfg_fmtint(sHostbasedUsesNameFromPacketOnly, o->hostbased_uses_name_from_packet_only); dump_cfg_fmtint(sRSAAuthentication, o->rsa_authentication); dump_cfg_fmtint(sPubkeyAuthentication, o->pubkey_authentication); #ifdef KRB5 dump_cfg_fmtint(sKerberosAuthentication, o->kerberos_authentication); dump_cfg_fmtint(sKerberosOrLocalPasswd, o->kerberos_or_local_passwd); dump_cfg_fmtint(sKerberosTicketCleanup, o->kerberos_ticket_cleanup); # ifdef USE_AFS dump_cfg_fmtint(sKerberosGetAFSToken, o->kerberos_get_afs_token); # endif #endif #ifdef GSSAPI dump_cfg_fmtint(sGssAuthentication, o->gss_authentication); dump_cfg_fmtint(sGssCleanupCreds, o->gss_cleanup_creds); #endif dump_cfg_fmtint(sPasswordAuthentication, o->password_authentication); dump_cfg_fmtint(sKbdInteractiveAuthentication, o->kbd_interactive_authentication); dump_cfg_fmtint(sChallengeResponseAuthentication, o->challenge_response_authentication); dump_cfg_fmtint(sPrintMotd, o->print_motd); #ifndef DISABLE_LASTLOG dump_cfg_fmtint(sPrintLastLog, o->print_lastlog); #endif dump_cfg_fmtint(sX11Forwarding, o->x11_forwarding); dump_cfg_fmtint(sX11UseLocalhost, o->x11_use_localhost); dump_cfg_fmtint(sPermitTTY, o->permit_tty); dump_cfg_fmtint(sPermitUserRC, o->permit_user_rc); dump_cfg_fmtint(sStrictModes, o->strict_modes); dump_cfg_fmtint(sTCPKeepAlive, o->tcp_keep_alive); dump_cfg_fmtint(sEmptyPasswd, o->permit_empty_passwd); dump_cfg_fmtint(sPermitUserEnvironment, o->permit_user_env); dump_cfg_fmtint(sUseLogin, o->use_login); dump_cfg_fmtint(sCompression, o->compression); dump_cfg_fmtint(sGatewayPorts, o->fwd_opts.gateway_ports); dump_cfg_fmtint(sUseDNS, o->use_dns); dump_cfg_fmtint(sAllowTcpForwarding, o->allow_tcp_forwarding); dump_cfg_fmtint(sAllowAgentForwarding, o->allow_agent_forwarding); dump_cfg_fmtint(sAllowStreamLocalForwarding, o->allow_streamlocal_forwarding); dump_cfg_fmtint(sUsePrivilegeSeparation, use_privsep); dump_cfg_fmtint(sFingerprintHash, o->fingerprint_hash); + dump_cfg_fmtint(sUseBlacklist, o->use_blacklist); /* string arguments */ dump_cfg_string(sPidFile, o->pid_file); dump_cfg_string(sXAuthLocation, o->xauth_location); dump_cfg_string(sCiphers, o->ciphers ? o->ciphers : KEX_SERVER_ENCRYPT); dump_cfg_string(sMacs, o->macs ? o->macs : KEX_SERVER_MAC); dump_cfg_string(sBanner, o->banner); dump_cfg_string(sForceCommand, o->adm_forced_command); dump_cfg_string(sChrootDirectory, o->chroot_directory); dump_cfg_string(sTrustedUserCAKeys, o->trusted_user_ca_keys); dump_cfg_string(sRevokedKeys, o->revoked_keys_file); dump_cfg_string(sAuthorizedPrincipalsFile, o->authorized_principals_file); dump_cfg_string(sVersionAddendum, *o->version_addendum == '\0' ? "none" : o->version_addendum); dump_cfg_string(sAuthorizedKeysCommand, o->authorized_keys_command); dump_cfg_string(sAuthorizedKeysCommandUser, o->authorized_keys_command_user); dump_cfg_string(sAuthorizedPrincipalsCommand, o->authorized_principals_command); dump_cfg_string(sAuthorizedPrincipalsCommandUser, o->authorized_principals_command_user); dump_cfg_string(sHostKeyAgent, o->host_key_agent); dump_cfg_string(sKexAlgorithms, o->kex_algorithms ? o->kex_algorithms : KEX_SERVER_KEX); dump_cfg_string(sHostbasedAcceptedKeyTypes, o->hostbased_key_types ? o->hostbased_key_types : KEX_DEFAULT_PK_ALG); dump_cfg_string(sHostKeyAlgorithms, o->hostkeyalgorithms ? o->hostkeyalgorithms : KEX_DEFAULT_PK_ALG); dump_cfg_string(sPubkeyAcceptedKeyTypes, o->pubkey_key_types ? o->pubkey_key_types : KEX_DEFAULT_PK_ALG); /* string arguments requiring a lookup */ dump_cfg_string(sLogLevel, log_level_name(o->log_level)); dump_cfg_string(sLogFacility, log_facility_name(o->log_facility)); /* string array arguments */ dump_cfg_strarray_oneline(sAuthorizedKeysFile, o->num_authkeys_files, o->authorized_keys_files); dump_cfg_strarray(sHostKeyFile, o->num_host_key_files, o->host_key_files); dump_cfg_strarray(sHostCertificate, o->num_host_cert_files, o->host_cert_files); dump_cfg_strarray(sAllowUsers, o->num_allow_users, o->allow_users); dump_cfg_strarray(sDenyUsers, o->num_deny_users, o->deny_users); dump_cfg_strarray(sAllowGroups, o->num_allow_groups, o->allow_groups); dump_cfg_strarray(sDenyGroups, o->num_deny_groups, o->deny_groups); dump_cfg_strarray(sAcceptEnv, o->num_accept_env, o->accept_env); dump_cfg_strarray_oneline(sAuthenticationMethods, o->num_auth_methods, o->auth_methods); /* other arguments */ for (i = 0; i < o->num_subsystems; i++) printf("subsystem %s %s\n", o->subsystem_name[i], o->subsystem_args[i]); printf("maxstartups %d:%d:%d\n", o->max_startups_begin, o->max_startups_rate, o->max_startups); for (i = 0; tunmode_desc[i].val != -1; i++) if (tunmode_desc[i].val == o->permit_tun) { s = tunmode_desc[i].text; break; } dump_cfg_string(sPermitTunnel, s); printf("ipqos %s ", iptos2str(o->ip_qos_interactive)); printf("%s\n", iptos2str(o->ip_qos_bulk)); printf("rekeylimit %llu %d\n", (unsigned long long)o->rekey_limit, o->rekey_interval); channel_print_adm_permitted_opens(); } diff --git a/crypto/openssh/servconf.h b/crypto/openssh/servconf.h index f4137af7d666..8c37a63dd4f4 100644 --- a/crypto/openssh/servconf.h +++ b/crypto/openssh/servconf.h @@ -1,254 +1,255 @@ /* $OpenBSD: servconf.h,v 1.120 2015/07/10 06:21:53 markus Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved * Definitions for server configuration data and for the functions reading it. * * As far as I am concerned, the code I have written for this software * can be used freely for any purpose. Any derived versions of this * software must be clearly marked as such, and if the derived work is * incompatible with the protocol description in the RFC file, it must be * called by a name other than "ssh" or "Secure Shell". */ #ifndef SERVCONF_H #define SERVCONF_H #define MAX_PORTS 256 /* Max # ports. */ #define MAX_ALLOW_USERS 256 /* Max # users on allow list. */ #define MAX_DENY_USERS 256 /* Max # users on deny list. */ #define MAX_ALLOW_GROUPS 256 /* Max # groups on allow list. */ #define MAX_DENY_GROUPS 256 /* Max # groups on deny list. */ #define MAX_SUBSYSTEMS 256 /* Max # subsystems. */ #define MAX_HOSTKEYS 256 /* Max # hostkeys. */ #define MAX_HOSTCERTS 256 /* Max # host certificates. */ #define MAX_ACCEPT_ENV 256 /* Max # of env vars. */ #define MAX_MATCH_GROUPS 256 /* Max # of groups for Match. */ #define MAX_AUTHKEYS_FILES 256 /* Max # of authorized_keys files. */ #define MAX_AUTH_METHODS 256 /* Max # of AuthenticationMethods. */ /* permit_root_login */ #define PERMIT_NOT_SET -1 #define PERMIT_NO 0 #define PERMIT_FORCED_ONLY 1 #define PERMIT_NO_PASSWD 2 #define PERMIT_YES 3 /* use_privsep */ #define PRIVSEP_OFF 0 #define PRIVSEP_ON 1 #define PRIVSEP_NOSANDBOX 2 /* AllowTCPForwarding */ #define FORWARD_DENY 0 #define FORWARD_REMOTE (1) #define FORWARD_LOCAL (1<<1) #define FORWARD_ALLOW (FORWARD_REMOTE|FORWARD_LOCAL) #define DEFAULT_AUTH_FAIL_MAX 6 /* Default for MaxAuthTries */ #define DEFAULT_SESSIONS_MAX 10 /* Default for MaxSessions */ /* Magic name for internal sftp-server */ #define INTERNAL_SFTP_NAME "internal-sftp" typedef struct { u_int num_ports; u_int ports_from_cmdline; int ports[MAX_PORTS]; /* Port number to listen on. */ u_int num_queued_listens; char **queued_listen_addrs; int *queued_listen_ports; struct addrinfo *listen_addrs; /* Addresses on which the server listens. */ int address_family; /* Address family used by the server. */ char *host_key_files[MAX_HOSTKEYS]; /* Files containing host keys. */ int num_host_key_files; /* Number of files for host keys. */ char *host_cert_files[MAX_HOSTCERTS]; /* Files containing host certs. */ int num_host_cert_files; /* Number of files for host certs. */ char *host_key_agent; /* ssh-agent socket for host keys. */ char *pid_file; /* Where to put our pid */ int server_key_bits;/* Size of the server key. */ int login_grace_time; /* Disconnect if no auth in this time * (sec). */ int key_regeneration_time; /* Server key lifetime (seconds). */ int permit_root_login; /* PERMIT_*, see above */ int ignore_rhosts; /* Ignore .rhosts and .shosts. */ int ignore_user_known_hosts; /* Ignore ~/.ssh/known_hosts * for RhostsRsaAuth */ int print_motd; /* If true, print /etc/motd. */ int print_lastlog; /* If true, print lastlog */ int x11_forwarding; /* If true, permit inet (spoofing) X11 fwd. */ int x11_display_offset; /* What DISPLAY number to start * searching at */ int x11_use_localhost; /* If true, use localhost for fake X11 server. */ char *xauth_location; /* Location of xauth program */ int permit_tty; /* If false, deny pty allocation */ int permit_user_rc; /* If false, deny ~/.ssh/rc execution */ int strict_modes; /* If true, require string home dir modes. */ int tcp_keep_alive; /* If true, set SO_KEEPALIVE. */ int ip_qos_interactive; /* IP ToS/DSCP/class for interactive */ int ip_qos_bulk; /* IP ToS/DSCP/class for bulk traffic */ char *ciphers; /* Supported SSH2 ciphers. */ char *macs; /* Supported SSH2 macs. */ char *kex_algorithms; /* SSH2 kex methods in order of preference. */ int protocol; /* Supported protocol versions. */ struct ForwardOptions fwd_opts; /* forwarding options */ SyslogFacility log_facility; /* Facility for system logging. */ LogLevel log_level; /* Level for system logging. */ int rhosts_rsa_authentication; /* If true, permit rhosts RSA * authentication. */ int hostbased_authentication; /* If true, permit ssh2 hostbased auth */ int hostbased_uses_name_from_packet_only; /* experimental */ char *hostbased_key_types; /* Key types allowed for hostbased */ char *hostkeyalgorithms; /* SSH2 server key types */ int rsa_authentication; /* If true, permit RSA authentication. */ int pubkey_authentication; /* If true, permit ssh2 pubkey authentication. */ char *pubkey_key_types; /* Key types allowed for public key */ int kerberos_authentication; /* If true, permit Kerberos * authentication. */ int kerberos_or_local_passwd; /* If true, permit kerberos * and any other password * authentication mechanism, * such as SecurID or * /etc/passwd */ int kerberos_ticket_cleanup; /* If true, destroy ticket * file on logout. */ int kerberos_get_afs_token; /* If true, try to get AFS token if * authenticated with Kerberos. */ int gss_authentication; /* If true, permit GSSAPI authentication */ int gss_cleanup_creds; /* If true, destroy cred cache on logout */ int gss_strict_acceptor; /* If true, restrict the GSSAPI acceptor name */ int password_authentication; /* If true, permit password * authentication. */ int kbd_interactive_authentication; /* If true, permit */ int challenge_response_authentication; int permit_empty_passwd; /* If false, do not permit empty * passwords. */ int permit_user_env; /* If true, read ~/.ssh/environment */ int use_login; /* If true, login(1) is used */ int compression; /* If true, compression is allowed */ int allow_tcp_forwarding; /* One of FORWARD_* */ int allow_streamlocal_forwarding; /* One of FORWARD_* */ int allow_agent_forwarding; u_int num_allow_users; char *allow_users[MAX_ALLOW_USERS]; u_int num_deny_users; char *deny_users[MAX_DENY_USERS]; u_int num_allow_groups; char *allow_groups[MAX_ALLOW_GROUPS]; u_int num_deny_groups; char *deny_groups[MAX_DENY_GROUPS]; u_int num_subsystems; char *subsystem_name[MAX_SUBSYSTEMS]; char *subsystem_command[MAX_SUBSYSTEMS]; char *subsystem_args[MAX_SUBSYSTEMS]; u_int num_accept_env; char *accept_env[MAX_ACCEPT_ENV]; int max_startups_begin; int max_startups_rate; int max_startups; int max_authtries; int max_sessions; char *banner; /* SSH-2 banner message */ int use_dns; int client_alive_interval; /* * poke the client this often to * see if it's still there */ int client_alive_count_max; /* * If the client is unresponsive * for this many intervals above, * disconnect the session */ u_int num_authkeys_files; /* Files containing public keys */ char *authorized_keys_files[MAX_AUTHKEYS_FILES]; char *adm_forced_command; int use_pam; /* Enable auth via PAM */ int permit_tun; int num_permitted_opens; char *chroot_directory; char *revoked_keys_file; char *trusted_user_ca_keys; char *authorized_keys_command; char *authorized_keys_command_user; char *authorized_principals_file; char *authorized_principals_command; char *authorized_principals_command_user; int64_t rekey_limit; int rekey_interval; char *version_addendum; /* Appended to SSH banner */ u_int num_auth_methods; char *auth_methods[MAX_AUTH_METHODS]; int fingerprint_hash; + int use_blacklist; } ServerOptions; /* Information about the incoming connection as used by Match */ struct connection_info { const char *user; const char *host; /* possibly resolved hostname */ const char *address; /* remote address */ const char *laddress; /* local address */ int lport; /* local port */ }; /* * These are string config options that must be copied between the * Match sub-config and the main config, and must be sent from the * privsep slave to the privsep master. We use a macro to ensure all * the options are copied and the copies are done in the correct order. * * NB. an option must appear in servconf.c:copy_set_server_options() or * COPY_MATCH_STRING_OPTS here but never both. */ #define COPY_MATCH_STRING_OPTS() do { \ M_CP_STROPT(banner); \ M_CP_STROPT(trusted_user_ca_keys); \ M_CP_STROPT(revoked_keys_file); \ M_CP_STROPT(authorized_keys_command); \ M_CP_STROPT(authorized_keys_command_user); \ M_CP_STROPT(authorized_principals_file); \ M_CP_STROPT(authorized_principals_command); \ M_CP_STROPT(authorized_principals_command_user); \ M_CP_STROPT(hostbased_key_types); \ M_CP_STROPT(pubkey_key_types); \ M_CP_STRARRAYOPT(authorized_keys_files, num_authkeys_files); \ M_CP_STRARRAYOPT(allow_users, num_allow_users); \ M_CP_STRARRAYOPT(deny_users, num_deny_users); \ M_CP_STRARRAYOPT(allow_groups, num_allow_groups); \ M_CP_STRARRAYOPT(deny_groups, num_deny_groups); \ M_CP_STRARRAYOPT(accept_env, num_accept_env); \ M_CP_STRARRAYOPT(auth_methods, num_auth_methods); \ } while (0) struct connection_info *get_connection_info(int, int); void initialize_server_options(ServerOptions *); void fill_default_server_options(ServerOptions *); int process_server_config_line(ServerOptions *, char *, const char *, int, int *, struct connection_info *); void load_server_config(const char *, Buffer *); void parse_server_config(ServerOptions *, const char *, Buffer *, struct connection_info *); void parse_server_match_config(ServerOptions *, struct connection_info *); int parse_server_match_testspec(struct connection_info *, char *); int server_match_spec_complete(struct connection_info *); void copy_set_server_options(ServerOptions *, ServerOptions *, int); void dump_config(ServerOptions *); char *derelativise_path(const char *); #endif /* SERVCONF_H */ diff --git a/crypto/openssh/sshd.c b/crypto/openssh/sshd.c index dd7fcdda3e94..38b772d10855 100644 --- a/crypto/openssh/sshd.c +++ b/crypto/openssh/sshd.c @@ -1,2700 +1,2705 @@ /* $OpenBSD: sshd.c,v 1.465 2016/02/15 09:47:49 dtucker Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved * This program is the ssh daemon. It listens for connections from clients, * and performs authentication, executes use commands or shell, and forwards * information to/from the application to the user client over an encrypted * connection. This can also handle forwarding of X11, TCP/IP, and * authentication agent connections. * * As far as I am concerned, the code I have written for this software * can be used freely for any purpose. Any derived versions of this * software must be clearly marked as such, and if the derived work is * incompatible with the protocol description in the RFC file, it must be * called by a name other than "ssh" or "Secure Shell". * * SSH2 implementation: * Privilege Separation: * * Copyright (c) 2000, 2001, 2002 Markus Friedl. All rights reserved. * Copyright (c) 2002 Niels Provos. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "includes.h" __RCSID("$FreeBSD$"); #include #include #include #include #ifdef HAVE_SYS_STAT_H # include #endif #ifdef HAVE_SYS_TIME_H # include #endif #include "openbsd-compat/sys-tree.h" #include "openbsd-compat/sys-queue.h" #include #include #include #include #ifdef HAVE_PATHS_H #include #endif #include #include #include #include #include #include #include #include #include #ifdef WITH_OPENSSL #include #include #include #include "openbsd-compat/openssl-compat.h" #endif #ifdef HAVE_SECUREWARE #include #include #endif #ifdef __FreeBSD__ #include #if defined(GSSAPI) && defined(HAVE_GSSAPI_GSSAPI_H) #include #elif defined(GSSAPI) && defined(HAVE_GSSAPI_H) #include #endif #endif #include "xmalloc.h" #include "ssh.h" #include "ssh1.h" #include "ssh2.h" #include "rsa.h" #include "sshpty.h" #include "packet.h" #include "log.h" #include "buffer.h" #include "misc.h" #include "match.h" #include "servconf.h" #include "uidswap.h" #include "compat.h" #include "cipher.h" #include "digest.h" #include "key.h" #include "kex.h" #include "myproposal.h" #include "authfile.h" #include "pathnames.h" #include "atomicio.h" #include "canohost.h" #include "hostfile.h" #include "auth.h" #include "authfd.h" #include "msg.h" #include "dispatch.h" #include "channels.h" #include "session.h" #include "monitor_mm.h" #include "monitor.h" #ifdef GSSAPI #include "ssh-gss.h" #endif #include "monitor_wrap.h" #include "ssh-sandbox.h" #include "version.h" #include "ssherr.h" +#include "blacklist_client.h" #ifdef LIBWRAP #include #include int allow_severity; int deny_severity; #endif /* LIBWRAP */ #ifndef O_NOCTTY #define O_NOCTTY 0 #endif /* Re-exec fds */ #define REEXEC_DEVCRYPTO_RESERVED_FD (STDERR_FILENO + 1) #define REEXEC_STARTUP_PIPE_FD (STDERR_FILENO + 2) #define REEXEC_CONFIG_PASS_FD (STDERR_FILENO + 3) #define REEXEC_MIN_FREE_FD (STDERR_FILENO + 4) extern char *__progname; /* Server configuration options. */ ServerOptions options; /* Name of the server configuration file. */ char *config_file_name = _PATH_SERVER_CONFIG_FILE; /* * Debug mode flag. This can be set on the command line. If debug * mode is enabled, extra debugging output will be sent to the system * log, the daemon will not go to background, and will exit after processing * the first connection. */ int debug_flag = 0; /* Flag indicating that the daemon should only test the configuration and keys. */ int test_flag = 0; /* Flag indicating that the daemon is being started from inetd. */ int inetd_flag = 0; /* Flag indicating that sshd should not detach and become a daemon. */ int no_daemon_flag = 0; /* debug goes to stderr unless inetd_flag is set */ int log_stderr = 0; /* Saved arguments to main(). */ char **saved_argv; int saved_argc; /* re-exec */ int rexeced_flag = 0; int rexec_flag = 1; int rexec_argc = 0; char **rexec_argv; /* * The sockets that the server is listening; this is used in the SIGHUP * signal handler. */ #define MAX_LISTEN_SOCKS 16 int listen_socks[MAX_LISTEN_SOCKS]; int num_listen_socks = 0; /* * the client's version string, passed by sshd2 in compat mode. if != NULL, * sshd will skip the version-number exchange */ char *client_version_string = NULL; char *server_version_string = NULL; /* Daemon's agent connection */ int auth_sock = -1; int have_agent = 0; /* * Any really sensitive data in the application is contained in this * structure. The idea is that this structure could be locked into memory so * that the pages do not get written into swap. However, there are some * problems. The private key contains BIGNUMs, and we do not (in principle) * have access to the internals of them, and locking just the structure is * not very useful. Currently, memory locking is not implemented. */ struct { Key *server_key; /* ephemeral server key */ Key *ssh1_host_key; /* ssh1 host key */ Key **host_keys; /* all private host keys */ Key **host_pubkeys; /* all public host keys */ Key **host_certificates; /* all public host certificates */ int have_ssh1_key; int have_ssh2_key; u_char ssh1_cookie[SSH_SESSION_KEY_LENGTH]; } sensitive_data; /* * Flag indicating whether the RSA server key needs to be regenerated. * Is set in the SIGALRM handler and cleared when the key is regenerated. */ static volatile sig_atomic_t key_do_regen = 0; /* This is set to true when a signal is received. */ static volatile sig_atomic_t received_sighup = 0; static volatile sig_atomic_t received_sigterm = 0; /* session identifier, used by RSA-auth */ u_char session_id[16]; /* same for ssh2 */ u_char *session_id2 = NULL; u_int session_id2_len = 0; /* record remote hostname or ip */ u_int utmp_len = HOST_NAME_MAX+1; /* options.max_startup sized array of fd ints */ int *startup_pipes = NULL; int startup_pipe; /* in child */ /* variables used for privilege separation */ int use_privsep = -1; struct monitor *pmonitor = NULL; int privsep_is_preauth = 1; /* global authentication context */ Authctxt *the_authctxt = NULL; /* sshd_config buffer */ Buffer cfg; /* message to be displayed after login */ Buffer loginmsg; /* Unprivileged user */ struct passwd *privsep_pw = NULL; /* Prototypes for various functions defined later in this file. */ void destroy_sensitive_data(void); void demote_sensitive_data(void); #ifdef WITH_SSH1 static void do_ssh1_kex(void); #endif static void do_ssh2_kex(void); /* * Close all listening sockets */ static void close_listen_socks(void) { int i; for (i = 0; i < num_listen_socks; i++) close(listen_socks[i]); num_listen_socks = -1; } static void close_startup_pipes(void) { int i; if (startup_pipes) for (i = 0; i < options.max_startups; i++) if (startup_pipes[i] != -1) close(startup_pipes[i]); } /* * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP; * the effect is to reread the configuration file (and to regenerate * the server key). */ /*ARGSUSED*/ static void sighup_handler(int sig) { int save_errno = errno; received_sighup = 1; signal(SIGHUP, sighup_handler); errno = save_errno; } /* * Called from the main program after receiving SIGHUP. * Restarts the server. */ static void sighup_restart(void) { logit("Received SIGHUP; restarting."); platform_pre_restart(); close_listen_socks(); close_startup_pipes(); alarm(0); /* alarm timer persists across exec */ signal(SIGHUP, SIG_IGN); /* will be restored after exec */ execv(saved_argv[0], saved_argv); logit("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0], strerror(errno)); exit(1); } /* * Generic signal handler for terminating signals in the master daemon. */ /*ARGSUSED*/ static void sigterm_handler(int sig) { received_sigterm = sig; } /* * SIGCHLD handler. This is called whenever a child dies. This will then * reap any zombies left by exited children. */ /*ARGSUSED*/ static void main_sigchld_handler(int sig) { int save_errno = errno; pid_t pid; int status; while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || (pid < 0 && errno == EINTR)) ; signal(SIGCHLD, main_sigchld_handler); errno = save_errno; } /* * Signal handler for the alarm after the login grace period has expired. */ /*ARGSUSED*/ static void grace_alarm_handler(int sig) { if (use_privsep && pmonitor != NULL && pmonitor->m_pid > 0) kill(pmonitor->m_pid, SIGALRM); /* * Try to kill any processes that we have spawned, E.g. authorized * keys command helpers. */ if (getpgid(0) == getpid()) { signal(SIGTERM, SIG_IGN); kill(0, SIGTERM); } + BLACKLIST_NOTIFY(BLACKLIST_AUTH_FAIL); + /* Log error and exit. */ sigdie("Timeout before authentication for %s", get_remote_ipaddr()); } /* * Signal handler for the key regeneration alarm. Note that this * alarm only occurs in the daemon waiting for connections, and it does not * do anything with the private key or random state before forking. * Thus there should be no concurrency control/asynchronous execution * problems. */ static void generate_ephemeral_server_key(void) { verbose("Generating %s%d bit RSA key.", sensitive_data.server_key ? "new " : "", options.server_key_bits); if (sensitive_data.server_key != NULL) key_free(sensitive_data.server_key); sensitive_data.server_key = key_generate(KEY_RSA1, options.server_key_bits); verbose("RSA key generation complete."); arc4random_buf(sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); } /*ARGSUSED*/ static void key_regeneration_alarm(int sig) { int save_errno = errno; signal(SIGALRM, SIG_DFL); errno = save_errno; key_do_regen = 1; } static void sshd_exchange_identification(int sock_in, int sock_out) { u_int i; int mismatch; int remote_major, remote_minor; int major, minor; char *s, *newline = "\n"; char buf[256]; /* Must not be larger than remote_version. */ char remote_version[256]; /* Must be at least as big as buf. */ if ((options.protocol & SSH_PROTO_1) && (options.protocol & SSH_PROTO_2)) { major = PROTOCOL_MAJOR_1; minor = 99; } else if (options.protocol & SSH_PROTO_2) { major = PROTOCOL_MAJOR_2; minor = PROTOCOL_MINOR_2; newline = "\r\n"; } else { major = PROTOCOL_MAJOR_1; minor = PROTOCOL_MINOR_1; } xasprintf(&server_version_string, "SSH-%d.%d-%.100s%s%s%s", major, minor, SSH_VERSION, *options.version_addendum == '\0' ? "" : " ", options.version_addendum, newline); /* Send our protocol version identification. */ if (atomicio(vwrite, sock_out, server_version_string, strlen(server_version_string)) != strlen(server_version_string)) { logit("Could not write ident string to %s", get_remote_ipaddr()); cleanup_exit(255); } /* Read other sides version identification. */ memset(buf, 0, sizeof(buf)); for (i = 0; i < sizeof(buf) - 1; i++) { if (atomicio(read, sock_in, &buf[i], 1) != 1) { logit("Did not receive identification string from %s", get_remote_ipaddr()); cleanup_exit(255); } if (buf[i] == '\r') { buf[i] = 0; /* Kludge for F-Secure Macintosh < 1.0.2 */ if (i == 12 && strncmp(buf, "SSH-1.5-W1.0", 12) == 0) break; continue; } if (buf[i] == '\n') { buf[i] = 0; break; } } buf[sizeof(buf) - 1] = 0; client_version_string = xstrdup(buf); /* * Check that the versions match. In future this might accept * several versions and set appropriate flags to handle them. */ if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n", &remote_major, &remote_minor, remote_version) != 3) { s = "Protocol mismatch.\n"; (void) atomicio(vwrite, sock_out, s, strlen(s)); logit("Bad protocol version identification '%.100s' " "from %s port %d", client_version_string, get_remote_ipaddr(), get_remote_port()); close(sock_in); close(sock_out); cleanup_exit(255); } debug("Client protocol version %d.%d; client software version %.100s", remote_major, remote_minor, remote_version); active_state->compat = compat_datafellows(remote_version); if ((datafellows & SSH_BUG_PROBE) != 0) { logit("probed from %s with %s. Don't panic.", get_remote_ipaddr(), client_version_string); cleanup_exit(255); } if ((datafellows & SSH_BUG_SCANNER) != 0) { logit("scanned from %s with %s. Don't panic.", get_remote_ipaddr(), client_version_string); cleanup_exit(255); } if ((datafellows & SSH_BUG_RSASIGMD5) != 0) { logit("Client version \"%.100s\" uses unsafe RSA signature " "scheme; disabling use of RSA keys", remote_version); } if ((datafellows & SSH_BUG_DERIVEKEY) != 0) { fatal("Client version \"%.100s\" uses unsafe key agreement; " "refusing connection", remote_version); } mismatch = 0; switch (remote_major) { case 1: if (remote_minor == 99) { if (options.protocol & SSH_PROTO_2) enable_compat20(); else mismatch = 1; break; } if (!(options.protocol & SSH_PROTO_1)) { mismatch = 1; break; } if (remote_minor < 3) { packet_disconnect("Your ssh version is too old and " "is no longer supported. Please install a newer version."); } else if (remote_minor == 3) { /* note that this disables agent-forwarding */ enable_compat13(); } break; case 2: if (options.protocol & SSH_PROTO_2) { enable_compat20(); break; } /* FALLTHROUGH */ default: mismatch = 1; break; } chop(server_version_string); debug("Local version string %.200s", server_version_string); if (mismatch) { s = "Protocol major versions differ.\n"; (void) atomicio(vwrite, sock_out, s, strlen(s)); close(sock_in); close(sock_out); logit("Protocol major versions differ for %s: %.200s vs. %.200s", get_remote_ipaddr(), server_version_string, client_version_string); cleanup_exit(255); } } /* Destroy the host and server keys. They will no longer be needed. */ void destroy_sensitive_data(void) { int i; if (sensitive_data.server_key) { key_free(sensitive_data.server_key); sensitive_data.server_key = NULL; } for (i = 0; i < options.num_host_key_files; i++) { if (sensitive_data.host_keys[i]) { key_free(sensitive_data.host_keys[i]); sensitive_data.host_keys[i] = NULL; } if (sensitive_data.host_certificates[i]) { key_free(sensitive_data.host_certificates[i]); sensitive_data.host_certificates[i] = NULL; } } sensitive_data.ssh1_host_key = NULL; explicit_bzero(sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); } /* Demote private to public keys for network child */ void demote_sensitive_data(void) { Key *tmp; int i; if (sensitive_data.server_key) { tmp = key_demote(sensitive_data.server_key); key_free(sensitive_data.server_key); sensitive_data.server_key = tmp; } for (i = 0; i < options.num_host_key_files; i++) { if (sensitive_data.host_keys[i]) { tmp = key_demote(sensitive_data.host_keys[i]); key_free(sensitive_data.host_keys[i]); sensitive_data.host_keys[i] = tmp; if (tmp->type == KEY_RSA1) sensitive_data.ssh1_host_key = tmp; } /* Certs do not need demotion */ } /* We do not clear ssh1_host key and cookie. XXX - Okay Niels? */ } static void privsep_preauth_child(void) { u_int32_t rnd[256]; gid_t gidset[1]; /* Enable challenge-response authentication for privilege separation */ privsep_challenge_enable(); #ifdef GSSAPI /* Cache supported mechanism OIDs for later use */ if (options.gss_authentication) ssh_gssapi_prepare_supported_oids(); #endif arc4random_stir(); arc4random_buf(rnd, sizeof(rnd)); #ifdef WITH_OPENSSL RAND_seed(rnd, sizeof(rnd)); if ((RAND_bytes((u_char *)rnd, 1)) != 1) fatal("%s: RAND_bytes failed", __func__); #endif explicit_bzero(rnd, sizeof(rnd)); /* Demote the private keys to public keys. */ demote_sensitive_data(); /* Demote the child */ if (getuid() == 0 || geteuid() == 0) { /* Change our root directory */ if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1) fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR, strerror(errno)); if (chdir("/") == -1) fatal("chdir(\"/\"): %s", strerror(errno)); /* Drop our privileges */ debug3("privsep user:group %u:%u", (u_int)privsep_pw->pw_uid, (u_int)privsep_pw->pw_gid); gidset[0] = privsep_pw->pw_gid; if (setgroups(1, gidset) < 0) fatal("setgroups: %.100s", strerror(errno)); permanently_set_uid(privsep_pw); } } static int privsep_preauth(Authctxt *authctxt) { int status, r; pid_t pid; struct ssh_sandbox *box = NULL; /* Set up unprivileged child process to deal with network data */ pmonitor = monitor_init(); /* Store a pointer to the kex for later rekeying */ pmonitor->m_pkex = &active_state->kex; if (use_privsep == PRIVSEP_ON) box = ssh_sandbox_init(pmonitor); pid = fork(); if (pid == -1) { fatal("fork of unprivileged child failed"); } else if (pid != 0) { debug2("Network child is on pid %ld", (long)pid); pmonitor->m_pid = pid; if (have_agent) { r = ssh_get_authentication_socket(&auth_sock); if (r != 0) { error("Could not get agent socket: %s", ssh_err(r)); have_agent = 0; } } if (box != NULL) ssh_sandbox_parent_preauth(box, pid); monitor_child_preauth(authctxt, pmonitor); /* Sync memory */ monitor_sync(pmonitor); /* Wait for the child's exit status */ while (waitpid(pid, &status, 0) < 0) { if (errno == EINTR) continue; pmonitor->m_pid = -1; fatal("%s: waitpid: %s", __func__, strerror(errno)); } privsep_is_preauth = 0; pmonitor->m_pid = -1; if (WIFEXITED(status)) { if (WEXITSTATUS(status) != 0) fatal("%s: preauth child exited with status %d", __func__, WEXITSTATUS(status)); } else if (WIFSIGNALED(status)) fatal("%s: preauth child terminated by signal %d", __func__, WTERMSIG(status)); if (box != NULL) ssh_sandbox_parent_finish(box); return 1; } else { /* child */ close(pmonitor->m_sendfd); close(pmonitor->m_log_recvfd); /* Arrange for logging to be sent to the monitor */ set_log_handler(mm_log_handler, pmonitor); privsep_preauth_child(); setproctitle("%s", "[net]"); if (box != NULL) ssh_sandbox_child(box); return 0; } } static void privsep_postauth(Authctxt *authctxt) { u_int32_t rnd[256]; #ifdef DISABLE_FD_PASSING if (1) { #else if (authctxt->pw->pw_uid == 0 || options.use_login) { #endif /* File descriptor passing is broken or root login */ use_privsep = 0; goto skip; } /* New socket pair */ monitor_reinit(pmonitor); pmonitor->m_pid = fork(); if (pmonitor->m_pid == -1) fatal("fork of unprivileged child failed"); else if (pmonitor->m_pid != 0) { verbose("User child is on pid %ld", (long)pmonitor->m_pid); buffer_clear(&loginmsg); monitor_child_postauth(pmonitor); /* NEVERREACHED */ exit(0); } /* child */ close(pmonitor->m_sendfd); pmonitor->m_sendfd = -1; /* Demote the private keys to public keys. */ demote_sensitive_data(); arc4random_stir(); arc4random_buf(rnd, sizeof(rnd)); #ifdef WITH_OPENSSL RAND_seed(rnd, sizeof(rnd)); if ((RAND_bytes((u_char *)rnd, 1)) != 1) fatal("%s: RAND_bytes failed", __func__); #endif explicit_bzero(rnd, sizeof(rnd)); /* Drop privileges */ do_setusercontext(authctxt->pw); skip: /* It is safe now to apply the key state */ monitor_apply_keystate(pmonitor); /* * Tell the packet layer that authentication was successful, since * this information is not part of the key state. */ packet_set_authenticated(); } static char * list_hostkey_types(void) { Buffer b; const char *p; char *ret; int i; Key *key; buffer_init(&b); for (i = 0; i < options.num_host_key_files; i++) { key = sensitive_data.host_keys[i]; if (key == NULL) key = sensitive_data.host_pubkeys[i]; if (key == NULL || key->type == KEY_RSA1) continue; /* Check that the key is accepted in HostkeyAlgorithms */ if (match_pattern_list(sshkey_ssh_name(key), options.hostkeyalgorithms, 0) != 1) { debug3("%s: %s key not permitted by HostkeyAlgorithms", __func__, sshkey_ssh_name(key)); continue; } switch (key->type) { case KEY_RSA: case KEY_DSA: case KEY_ECDSA: case KEY_ED25519: if (buffer_len(&b) > 0) buffer_append(&b, ",", 1); p = key_ssh_name(key); buffer_append(&b, p, strlen(p)); /* for RSA we also support SHA2 signatures */ if (key->type == KEY_RSA) { p = ",rsa-sha2-512,rsa-sha2-256"; buffer_append(&b, p, strlen(p)); } break; } /* If the private key has a cert peer, then list that too */ key = sensitive_data.host_certificates[i]; if (key == NULL) continue; switch (key->type) { case KEY_RSA_CERT: case KEY_DSA_CERT: case KEY_ECDSA_CERT: case KEY_ED25519_CERT: if (buffer_len(&b) > 0) buffer_append(&b, ",", 1); p = key_ssh_name(key); buffer_append(&b, p, strlen(p)); break; } } buffer_append(&b, "\0", 1); ret = xstrdup(buffer_ptr(&b)); buffer_free(&b); debug("list_hostkey_types: %s", ret); return ret; } static Key * get_hostkey_by_type(int type, int nid, int need_private, struct ssh *ssh) { int i; Key *key; for (i = 0; i < options.num_host_key_files; i++) { switch (type) { case KEY_RSA_CERT: case KEY_DSA_CERT: case KEY_ECDSA_CERT: case KEY_ED25519_CERT: key = sensitive_data.host_certificates[i]; break; default: key = sensitive_data.host_keys[i]; if (key == NULL && !need_private) key = sensitive_data.host_pubkeys[i]; break; } if (key != NULL && key->type == type && (key->type != KEY_ECDSA || key->ecdsa_nid == nid)) return need_private ? sensitive_data.host_keys[i] : key; } return NULL; } Key * get_hostkey_public_by_type(int type, int nid, struct ssh *ssh) { return get_hostkey_by_type(type, nid, 0, ssh); } Key * get_hostkey_private_by_type(int type, int nid, struct ssh *ssh) { return get_hostkey_by_type(type, nid, 1, ssh); } Key * get_hostkey_by_index(int ind) { if (ind < 0 || ind >= options.num_host_key_files) return (NULL); return (sensitive_data.host_keys[ind]); } Key * get_hostkey_public_by_index(int ind, struct ssh *ssh) { if (ind < 0 || ind >= options.num_host_key_files) return (NULL); return (sensitive_data.host_pubkeys[ind]); } int get_hostkey_index(Key *key, int compare, struct ssh *ssh) { int i; for (i = 0; i < options.num_host_key_files; i++) { if (key_is_cert(key)) { if (key == sensitive_data.host_certificates[i] || (compare && sensitive_data.host_certificates[i] && sshkey_equal(key, sensitive_data.host_certificates[i]))) return (i); } else { if (key == sensitive_data.host_keys[i] || (compare && sensitive_data.host_keys[i] && sshkey_equal(key, sensitive_data.host_keys[i]))) return (i); if (key == sensitive_data.host_pubkeys[i] || (compare && sensitive_data.host_pubkeys[i] && sshkey_equal(key, sensitive_data.host_pubkeys[i]))) return (i); } } return (-1); } /* Inform the client of all hostkeys */ static void notify_hostkeys(struct ssh *ssh) { struct sshbuf *buf; struct sshkey *key; int i, nkeys, r; char *fp; /* Some clients cannot cope with the hostkeys message, skip those. */ if (datafellows & SSH_BUG_HOSTKEYS) return; if ((buf = sshbuf_new()) == NULL) fatal("%s: sshbuf_new", __func__); for (i = nkeys = 0; i < options.num_host_key_files; i++) { key = get_hostkey_public_by_index(i, ssh); if (key == NULL || key->type == KEY_UNSPEC || key->type == KEY_RSA1 || sshkey_is_cert(key)) continue; fp = sshkey_fingerprint(key, options.fingerprint_hash, SSH_FP_DEFAULT); debug3("%s: key %d: %s %s", __func__, i, sshkey_ssh_name(key), fp); free(fp); if (nkeys == 0) { packet_start(SSH2_MSG_GLOBAL_REQUEST); packet_put_cstring("hostkeys-00@openssh.com"); packet_put_char(0); /* want-reply */ } sshbuf_reset(buf); if ((r = sshkey_putb(key, buf)) != 0) fatal("%s: couldn't put hostkey %d: %s", __func__, i, ssh_err(r)); packet_put_string(sshbuf_ptr(buf), sshbuf_len(buf)); nkeys++; } debug3("%s: sent %d hostkeys", __func__, nkeys); if (nkeys == 0) fatal("%s: no hostkeys", __func__); packet_send(); sshbuf_free(buf); } /* * returns 1 if connection should be dropped, 0 otherwise. * dropping starts at connection #max_startups_begin with a probability * of (max_startups_rate/100). the probability increases linearly until * all connections are dropped for startups > max_startups */ static int drop_connection(int startups) { int p, r; if (startups < options.max_startups_begin) return 0; if (startups >= options.max_startups) return 1; if (options.max_startups_rate == 100) return 1; p = 100 - options.max_startups_rate; p *= startups - options.max_startups_begin; p /= options.max_startups - options.max_startups_begin; p += options.max_startups_rate; r = arc4random_uniform(100); debug("drop_connection: p %d, r %d", p, r); return (r < p) ? 1 : 0; } static void usage(void) { if (options.version_addendum && *options.version_addendum != '\0') fprintf(stderr, "%s %s, %s\n", SSH_RELEASE, options.version_addendum, OPENSSL_VERSION); else fprintf(stderr, "%s, %s\n", SSH_RELEASE, OPENSSL_VERSION); fprintf(stderr, "usage: sshd [-46DdeiqTt] [-b bits] [-C connection_spec] [-c host_cert_file]\n" " [-E log_file] [-f config_file] [-g login_grace_time]\n" " [-h host_key_file] [-k key_gen_time] [-o option] [-p port]\n" " [-u len]\n" ); exit(1); } static void send_rexec_state(int fd, Buffer *conf) { Buffer m; debug3("%s: entering fd = %d config len %d", __func__, fd, buffer_len(conf)); /* * Protocol from reexec master to child: * string configuration * u_int ephemeral_key_follows * bignum e (only if ephemeral_key_follows == 1) * bignum n " * bignum d " * bignum iqmp " * bignum p " * bignum q " * string rngseed (only if OpenSSL is not self-seeded) */ buffer_init(&m); buffer_put_cstring(&m, buffer_ptr(conf)); #ifdef WITH_SSH1 if (sensitive_data.server_key != NULL && sensitive_data.server_key->type == KEY_RSA1) { buffer_put_int(&m, 1); buffer_put_bignum(&m, sensitive_data.server_key->rsa->e); buffer_put_bignum(&m, sensitive_data.server_key->rsa->n); buffer_put_bignum(&m, sensitive_data.server_key->rsa->d); buffer_put_bignum(&m, sensitive_data.server_key->rsa->iqmp); buffer_put_bignum(&m, sensitive_data.server_key->rsa->p); buffer_put_bignum(&m, sensitive_data.server_key->rsa->q); } else #endif buffer_put_int(&m, 0); #if defined(WITH_OPENSSL) && !defined(OPENSSL_PRNG_ONLY) rexec_send_rng_seed(&m); #endif if (ssh_msg_send(fd, 0, &m) == -1) fatal("%s: ssh_msg_send failed", __func__); buffer_free(&m); debug3("%s: done", __func__); } static void recv_rexec_state(int fd, Buffer *conf) { Buffer m; char *cp; u_int len; debug3("%s: entering fd = %d", __func__, fd); buffer_init(&m); if (ssh_msg_recv(fd, &m) == -1) fatal("%s: ssh_msg_recv failed", __func__); if (buffer_get_char(&m) != 0) fatal("%s: rexec version mismatch", __func__); cp = buffer_get_string(&m, &len); if (conf != NULL) buffer_append(conf, cp, len + 1); free(cp); if (buffer_get_int(&m)) { #ifdef WITH_SSH1 if (sensitive_data.server_key != NULL) key_free(sensitive_data.server_key); sensitive_data.server_key = key_new_private(KEY_RSA1); buffer_get_bignum(&m, sensitive_data.server_key->rsa->e); buffer_get_bignum(&m, sensitive_data.server_key->rsa->n); buffer_get_bignum(&m, sensitive_data.server_key->rsa->d); buffer_get_bignum(&m, sensitive_data.server_key->rsa->iqmp); buffer_get_bignum(&m, sensitive_data.server_key->rsa->p); buffer_get_bignum(&m, sensitive_data.server_key->rsa->q); if (rsa_generate_additional_parameters( sensitive_data.server_key->rsa) != 0) fatal("%s: rsa_generate_additional_parameters " "error", __func__); #endif } #if defined(WITH_OPENSSL) && !defined(OPENSSL_PRNG_ONLY) rexec_recv_rng_seed(&m); #endif buffer_free(&m); debug3("%s: done", __func__); } /* Accept a connection from inetd */ static void server_accept_inetd(int *sock_in, int *sock_out) { int fd; startup_pipe = -1; if (rexeced_flag) { close(REEXEC_CONFIG_PASS_FD); *sock_in = *sock_out = dup(STDIN_FILENO); if (!debug_flag) { startup_pipe = dup(REEXEC_STARTUP_PIPE_FD); close(REEXEC_STARTUP_PIPE_FD); } } else { *sock_in = dup(STDIN_FILENO); *sock_out = dup(STDOUT_FILENO); } /* * We intentionally do not close the descriptors 0, 1, and 2 * as our code for setting the descriptors won't work if * ttyfd happens to be one of those. */ if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { dup2(fd, STDIN_FILENO); dup2(fd, STDOUT_FILENO); if (!log_stderr) dup2(fd, STDERR_FILENO); if (fd > (log_stderr ? STDERR_FILENO : STDOUT_FILENO)) close(fd); } debug("inetd sockets after dupping: %d, %d", *sock_in, *sock_out); } /* * Listen for TCP connections */ static void server_listen(void) { int ret, listen_sock, on = 1; struct addrinfo *ai; char ntop[NI_MAXHOST], strport[NI_MAXSERV]; int socksize; socklen_t len; for (ai = options.listen_addrs; ai; ai = ai->ai_next) { if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) continue; if (num_listen_socks >= MAX_LISTEN_SOCKS) fatal("Too many listen sockets. " "Enlarge MAX_LISTEN_SOCKS"); if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV)) != 0) { error("getnameinfo failed: %.100s", ssh_gai_strerror(ret)); continue; } /* Create socket for listening. */ listen_sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); if (listen_sock < 0) { /* kernel may not support ipv6 */ verbose("socket: %.100s", strerror(errno)); continue; } if (set_nonblock(listen_sock) == -1) { close(listen_sock); continue; } /* * Set socket options. * Allow local port reuse in TIME_WAIT. */ if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) error("setsockopt SO_REUSEADDR: %s", strerror(errno)); /* Only communicate in IPv6 over AF_INET6 sockets. */ if (ai->ai_family == AF_INET6) sock_set_v6only(listen_sock); debug("Bind to port %s on %s.", strport, ntop); len = sizeof(socksize); getsockopt(listen_sock, SOL_SOCKET, SO_RCVBUF, &socksize, &len); debug("Server TCP RWIN socket size: %d", socksize); /* Bind the socket to the desired port. */ if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) { error("Bind to port %s on %s failed: %.200s.", strport, ntop, strerror(errno)); close(listen_sock); continue; } listen_socks[num_listen_socks] = listen_sock; num_listen_socks++; /* Start listening on the port. */ if (listen(listen_sock, SSH_LISTEN_BACKLOG) < 0) fatal("listen on [%s]:%s: %.100s", ntop, strport, strerror(errno)); logit("Server listening on %s port %s.", ntop, strport); } freeaddrinfo(options.listen_addrs); if (!num_listen_socks) fatal("Cannot bind any address."); } /* * The main TCP accept loop. Note that, for the non-debug case, returns * from this function are in a forked subprocess. */ static void server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s) { fd_set *fdset; int i, j, ret, maxfd; int key_used = 0, startups = 0; int startup_p[2] = { -1 , -1 }; struct sockaddr_storage from; socklen_t fromlen; pid_t pid; u_char rnd[256]; /* setup fd set for accept */ fdset = NULL; maxfd = 0; for (i = 0; i < num_listen_socks; i++) if (listen_socks[i] > maxfd) maxfd = listen_socks[i]; /* pipes connected to unauthenticated childs */ startup_pipes = xcalloc(options.max_startups, sizeof(int)); for (i = 0; i < options.max_startups; i++) startup_pipes[i] = -1; /* * Stay listening for connections until the system crashes or * the daemon is killed with a signal. */ for (;;) { if (received_sighup) sighup_restart(); free(fdset); fdset = xcalloc(howmany(maxfd + 1, NFDBITS), sizeof(fd_mask)); for (i = 0; i < num_listen_socks; i++) FD_SET(listen_socks[i], fdset); for (i = 0; i < options.max_startups; i++) if (startup_pipes[i] != -1) FD_SET(startup_pipes[i], fdset); /* Wait in select until there is a connection. */ ret = select(maxfd+1, fdset, NULL, NULL, NULL); if (ret < 0 && errno != EINTR) error("select: %.100s", strerror(errno)); if (received_sigterm) { logit("Received signal %d; terminating.", (int) received_sigterm); close_listen_socks(); if (options.pid_file != NULL) unlink(options.pid_file); exit(received_sigterm == SIGTERM ? 0 : 255); } if (key_used && key_do_regen) { generate_ephemeral_server_key(); key_used = 0; key_do_regen = 0; } if (ret < 0) continue; for (i = 0; i < options.max_startups; i++) if (startup_pipes[i] != -1 && FD_ISSET(startup_pipes[i], fdset)) { /* * the read end of the pipe is ready * if the child has closed the pipe * after successful authentication * or if the child has died */ close(startup_pipes[i]); startup_pipes[i] = -1; startups--; } for (i = 0; i < num_listen_socks; i++) { if (!FD_ISSET(listen_socks[i], fdset)) continue; fromlen = sizeof(from); *newsock = accept(listen_socks[i], (struct sockaddr *)&from, &fromlen); if (*newsock < 0) { if (errno != EINTR && errno != EWOULDBLOCK && errno != ECONNABORTED && errno != EAGAIN) error("accept: %.100s", strerror(errno)); if (errno == EMFILE || errno == ENFILE) usleep(100 * 1000); continue; } if (unset_nonblock(*newsock) == -1) { close(*newsock); continue; } if (drop_connection(startups) == 1) { debug("drop connection #%d", startups); close(*newsock); continue; } if (pipe(startup_p) == -1) { close(*newsock); continue; } if (rexec_flag && socketpair(AF_UNIX, SOCK_STREAM, 0, config_s) == -1) { error("reexec socketpair: %s", strerror(errno)); close(*newsock); close(startup_p[0]); close(startup_p[1]); continue; } for (j = 0; j < options.max_startups; j++) if (startup_pipes[j] == -1) { startup_pipes[j] = startup_p[0]; if (maxfd < startup_p[0]) maxfd = startup_p[0]; startups++; break; } /* * Got connection. Fork a child to handle it, unless * we are in debugging mode. */ if (debug_flag) { /* * In debugging mode. Close the listening * socket, and start processing the * connection without forking. */ debug("Server will not fork when running in debugging mode."); close_listen_socks(); *sock_in = *newsock; *sock_out = *newsock; close(startup_p[0]); close(startup_p[1]); startup_pipe = -1; pid = getpid(); if (rexec_flag) { send_rexec_state(config_s[0], &cfg); close(config_s[0]); } break; } /* * Normal production daemon. Fork, and have * the child process the connection. The * parent continues listening. */ platform_pre_fork(); if ((pid = fork()) == 0) { /* * Child. Close the listening and * max_startup sockets. Start using * the accepted socket. Reinitialize * logging (since our pid has changed). * We break out of the loop to handle * the connection. */ platform_post_fork_child(); startup_pipe = startup_p[1]; close_startup_pipes(); close_listen_socks(); *sock_in = *newsock; *sock_out = *newsock; log_init(__progname, options.log_level, options.log_facility, log_stderr); if (rexec_flag) close(config_s[0]); break; } /* Parent. Stay in the loop. */ platform_post_fork_parent(pid); if (pid < 0) error("fork: %.100s", strerror(errno)); else debug("Forked child %ld.", (long)pid); close(startup_p[1]); if (rexec_flag) { send_rexec_state(config_s[0], &cfg); close(config_s[0]); close(config_s[1]); } /* * Mark that the key has been used (it * was "given" to the child). */ if ((options.protocol & SSH_PROTO_1) && key_used == 0) { /* Schedule server key regeneration alarm. */ signal(SIGALRM, key_regeneration_alarm); alarm(options.key_regeneration_time); key_used = 1; } close(*newsock); /* * Ensure that our random state differs * from that of the child */ arc4random_stir(); arc4random_buf(rnd, sizeof(rnd)); #ifdef WITH_OPENSSL RAND_seed(rnd, sizeof(rnd)); if ((RAND_bytes((u_char *)rnd, 1)) != 1) fatal("%s: RAND_bytes failed", __func__); #endif explicit_bzero(rnd, sizeof(rnd)); } /* child process check (or debug mode) */ if (num_listen_socks < 0) break; } } /* * Main program for the daemon. */ int main(int ac, char **av) { extern char *optarg; extern int optind; int r, opt, i, j, on = 1; int sock_in = -1, sock_out = -1, newsock = -1; const char *remote_ip; int remote_port; char *fp, *line, *laddr, *logfile = NULL; int config_s[2] = { -1 , -1 }; u_int n; u_int64_t ibytes, obytes; mode_t new_umask; Key *key; Key *pubkey; int keytype; Authctxt *authctxt; struct connection_info *connection_info = get_connection_info(0, 0); ssh_malloc_init(); /* must be called before any mallocs */ #ifdef HAVE_SECUREWARE (void)set_auth_parameters(ac, av); #endif __progname = ssh_get_progname(av[0]); /* Save argv. Duplicate so setproctitle emulation doesn't clobber it */ saved_argc = ac; rexec_argc = ac; saved_argv = xcalloc(ac + 1, sizeof(*saved_argv)); for (i = 0; i < ac; i++) saved_argv[i] = xstrdup(av[i]); saved_argv[i] = NULL; #ifndef HAVE_SETPROCTITLE /* Prepare for later setproctitle emulation */ compat_init_setproctitle(ac, av); av = saved_argv; #endif if (geteuid() == 0 && setgroups(0, NULL) == -1) debug("setgroups(): %.200s", strerror(errno)); /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ sanitise_stdfd(); /* Initialize configuration options to their default values. */ initialize_server_options(&options); /* Parse command-line arguments. */ while ((opt = getopt(ac, av, "C:E:b:c:f:g:h:k:o:p:u:46DQRTdeiqrt")) != -1) { switch (opt) { case '4': options.address_family = AF_INET; break; case '6': options.address_family = AF_INET6; break; case 'f': config_file_name = optarg; break; case 'c': if (options.num_host_cert_files >= MAX_HOSTCERTS) { fprintf(stderr, "too many host certificates.\n"); exit(1); } options.host_cert_files[options.num_host_cert_files++] = derelativise_path(optarg); break; case 'd': if (debug_flag == 0) { debug_flag = 1; options.log_level = SYSLOG_LEVEL_DEBUG1; } else if (options.log_level < SYSLOG_LEVEL_DEBUG3) options.log_level++; break; case 'D': no_daemon_flag = 1; break; case 'E': logfile = optarg; /* FALLTHROUGH */ case 'e': log_stderr = 1; break; case 'i': inetd_flag = 1; break; case 'r': rexec_flag = 0; break; case 'R': rexeced_flag = 1; inetd_flag = 1; break; case 'Q': /* ignored */ break; case 'q': options.log_level = SYSLOG_LEVEL_QUIET; break; case 'b': options.server_key_bits = (int)strtonum(optarg, 256, 32768, NULL); break; case 'p': options.ports_from_cmdline = 1; if (options.num_ports >= MAX_PORTS) { fprintf(stderr, "too many ports.\n"); exit(1); } options.ports[options.num_ports++] = a2port(optarg); if (options.ports[options.num_ports-1] <= 0) { fprintf(stderr, "Bad port number.\n"); exit(1); } break; case 'g': if ((options.login_grace_time = convtime(optarg)) == -1) { fprintf(stderr, "Invalid login grace time.\n"); exit(1); } break; case 'k': if ((options.key_regeneration_time = convtime(optarg)) == -1) { fprintf(stderr, "Invalid key regeneration interval.\n"); exit(1); } break; case 'h': if (options.num_host_key_files >= MAX_HOSTKEYS) { fprintf(stderr, "too many host keys.\n"); exit(1); } options.host_key_files[options.num_host_key_files++] = derelativise_path(optarg); break; case 't': test_flag = 1; break; case 'T': test_flag = 2; break; case 'C': if (parse_server_match_testspec(connection_info, optarg) == -1) exit(1); break; case 'u': utmp_len = (u_int)strtonum(optarg, 0, HOST_NAME_MAX+1+1, NULL); if (utmp_len > HOST_NAME_MAX+1) { fprintf(stderr, "Invalid utmp length.\n"); exit(1); } break; case 'o': line = xstrdup(optarg); if (process_server_config_line(&options, line, "command-line", 0, NULL, NULL) != 0) exit(1); free(line); break; case '?': default: usage(); break; } } if (rexeced_flag || inetd_flag) rexec_flag = 0; if (!test_flag && (rexec_flag && (av[0] == NULL || *av[0] != '/'))) fatal("sshd re-exec requires execution with an absolute path"); if (rexeced_flag) closefrom(REEXEC_MIN_FREE_FD); else closefrom(REEXEC_DEVCRYPTO_RESERVED_FD); #ifdef WITH_OPENSSL OpenSSL_add_all_algorithms(); #endif /* If requested, redirect the logs to the specified logfile. */ if (logfile != NULL) log_redirect_stderr_to(logfile); /* * Force logging to stderr until we have loaded the private host * key (unless started from inetd) */ log_init(__progname, options.log_level == SYSLOG_LEVEL_NOT_SET ? SYSLOG_LEVEL_INFO : options.log_level, options.log_facility == SYSLOG_FACILITY_NOT_SET ? SYSLOG_FACILITY_AUTH : options.log_facility, log_stderr || !inetd_flag); /* * Unset KRB5CCNAME, otherwise the user's session may inherit it from * root's environment */ if (getenv("KRB5CCNAME") != NULL) (void) unsetenv("KRB5CCNAME"); #ifdef _UNICOS /* Cray can define user privs drop all privs now! * Not needed on PRIV_SU systems! */ drop_cray_privs(); #endif sensitive_data.server_key = NULL; sensitive_data.ssh1_host_key = NULL; sensitive_data.have_ssh1_key = 0; sensitive_data.have_ssh2_key = 0; /* * If we're doing an extended config test, make sure we have all of * the parameters we need. If we're not doing an extended test, * do not silently ignore connection test params. */ if (test_flag >= 2 && server_match_spec_complete(connection_info) == 0) fatal("user, host and addr are all required when testing " "Match configs"); if (test_flag < 2 && server_match_spec_complete(connection_info) >= 0) fatal("Config test connection parameter (-C) provided without " "test mode (-T)"); /* Fetch our configuration */ buffer_init(&cfg); if (rexeced_flag) recv_rexec_state(REEXEC_CONFIG_PASS_FD, &cfg); else if (strcasecmp(config_file_name, "none") != 0) load_server_config(config_file_name, &cfg); parse_server_config(&options, rexeced_flag ? "rexec" : config_file_name, &cfg, NULL); seed_rng(); /* Fill in default values for those options not explicitly set. */ fill_default_server_options(&options); /* challenge-response is implemented via keyboard interactive */ if (options.challenge_response_authentication) options.kbd_interactive_authentication = 1; /* Check that options are sensible */ if (options.authorized_keys_command_user == NULL && (options.authorized_keys_command != NULL && strcasecmp(options.authorized_keys_command, "none") != 0)) fatal("AuthorizedKeysCommand set without " "AuthorizedKeysCommandUser"); if (options.authorized_principals_command_user == NULL && (options.authorized_principals_command != NULL && strcasecmp(options.authorized_principals_command, "none") != 0)) fatal("AuthorizedPrincipalsCommand set without " "AuthorizedPrincipalsCommandUser"); /* * Check whether there is any path through configured auth methods. * Unfortunately it is not possible to verify this generally before * daemonisation in the presence of Match block, but this catches * and warns for trivial misconfigurations that could break login. */ if (options.num_auth_methods != 0) { if ((options.protocol & SSH_PROTO_1)) fatal("AuthenticationMethods is not supported with " "SSH protocol 1"); for (n = 0; n < options.num_auth_methods; n++) { if (auth2_methods_valid(options.auth_methods[n], 1) == 0) break; } if (n >= options.num_auth_methods) fatal("AuthenticationMethods cannot be satisfied by " "enabled authentication methods"); } /* set default channel AF */ channel_set_af(options.address_family); /* Check that there are no remaining arguments. */ if (optind < ac) { fprintf(stderr, "Extra argument %s.\n", av[optind]); exit(1); } debug("sshd version %s, %s", SSH_VERSION, #ifdef WITH_OPENSSL SSLeay_version(SSLEAY_VERSION) #else "without OpenSSL" #endif ); /* Store privilege separation user for later use if required. */ if ((privsep_pw = getpwnam(SSH_PRIVSEP_USER)) == NULL) { if (use_privsep || options.kerberos_authentication) fatal("Privilege separation user %s does not exist", SSH_PRIVSEP_USER); } else { explicit_bzero(privsep_pw->pw_passwd, strlen(privsep_pw->pw_passwd)); privsep_pw = pwcopy(privsep_pw); free(privsep_pw->pw_passwd); privsep_pw->pw_passwd = xstrdup("*"); } endpwent(); /* load host keys */ sensitive_data.host_keys = xcalloc(options.num_host_key_files, sizeof(Key *)); sensitive_data.host_pubkeys = xcalloc(options.num_host_key_files, sizeof(Key *)); if (options.host_key_agent) { if (strcmp(options.host_key_agent, SSH_AUTHSOCKET_ENV_NAME)) setenv(SSH_AUTHSOCKET_ENV_NAME, options.host_key_agent, 1); if ((r = ssh_get_authentication_socket(NULL)) == 0) have_agent = 1; else error("Could not connect to agent \"%s\": %s", options.host_key_agent, ssh_err(r)); } for (i = 0; i < options.num_host_key_files; i++) { if (options.host_key_files[i] == NULL) continue; key = key_load_private(options.host_key_files[i], "", NULL); pubkey = key_load_public(options.host_key_files[i], NULL); if (pubkey == NULL && key != NULL) pubkey = key_demote(key); sensitive_data.host_keys[i] = key; sensitive_data.host_pubkeys[i] = pubkey; if (key == NULL && pubkey != NULL && pubkey->type != KEY_RSA1 && have_agent) { debug("will rely on agent for hostkey %s", options.host_key_files[i]); keytype = pubkey->type; } else if (key != NULL) { keytype = key->type; } else { error("Could not load host key: %s", options.host_key_files[i]); sensitive_data.host_keys[i] = NULL; sensitive_data.host_pubkeys[i] = NULL; continue; } switch (keytype) { case KEY_RSA1: sensitive_data.ssh1_host_key = key; sensitive_data.have_ssh1_key = 1; break; case KEY_RSA: case KEY_DSA: case KEY_ECDSA: case KEY_ED25519: if (have_agent || key != NULL) sensitive_data.have_ssh2_key = 1; break; } if ((fp = sshkey_fingerprint(pubkey, options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) fatal("sshkey_fingerprint failed"); debug("%s host key #%d: %s %s", key ? "private" : "agent", i, keytype == KEY_RSA1 ? sshkey_type(pubkey) : sshkey_ssh_name(pubkey), fp); free(fp); } if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) { logit("Disabling protocol version 1. Could not load host key"); options.protocol &= ~SSH_PROTO_1; } if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) { logit("Disabling protocol version 2. Could not load host key"); options.protocol &= ~SSH_PROTO_2; } if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) { logit("sshd: no hostkeys available -- exiting."); exit(1); } /* * Load certificates. They are stored in an array at identical * indices to the public keys that they relate to. */ sensitive_data.host_certificates = xcalloc(options.num_host_key_files, sizeof(Key *)); for (i = 0; i < options.num_host_key_files; i++) sensitive_data.host_certificates[i] = NULL; for (i = 0; i < options.num_host_cert_files; i++) { if (options.host_cert_files[i] == NULL) continue; key = key_load_public(options.host_cert_files[i], NULL); if (key == NULL) { error("Could not load host certificate: %s", options.host_cert_files[i]); continue; } if (!key_is_cert(key)) { error("Certificate file is not a certificate: %s", options.host_cert_files[i]); key_free(key); continue; } /* Find matching private key */ for (j = 0; j < options.num_host_key_files; j++) { if (key_equal_public(key, sensitive_data.host_keys[j])) { sensitive_data.host_certificates[j] = key; break; } } if (j >= options.num_host_key_files) { error("No matching private key for certificate: %s", options.host_cert_files[i]); key_free(key); continue; } sensitive_data.host_certificates[j] = key; debug("host certificate: #%d type %d %s", j, key->type, key_type(key)); } #ifdef WITH_SSH1 /* Check certain values for sanity. */ if (options.protocol & SSH_PROTO_1) { if (options.server_key_bits < SSH_RSA_MINIMUM_MODULUS_SIZE || options.server_key_bits > OPENSSL_RSA_MAX_MODULUS_BITS) { fprintf(stderr, "Bad server key size.\n"); exit(1); } /* * Check that server and host key lengths differ sufficiently. This * is necessary to make double encryption work with rsaref. Oh, I * hate software patents. I dont know if this can go? Niels */ if (options.server_key_bits > BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) - SSH_KEY_BITS_RESERVED && options.server_key_bits < BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) { options.server_key_bits = BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED; debug("Forcing server key to %d bits to make it differ from host key.", options.server_key_bits); } } #endif if (use_privsep) { struct stat st; if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) || (S_ISDIR(st.st_mode) == 0)) fatal("Missing privilege separation directory: %s", _PATH_PRIVSEP_CHROOT_DIR); #ifdef HAVE_CYGWIN if (check_ntsec(_PATH_PRIVSEP_CHROOT_DIR) && (st.st_uid != getuid () || (st.st_mode & (S_IWGRP|S_IWOTH)) != 0)) #else if (st.st_uid != 0 || (st.st_mode & (S_IWGRP|S_IWOTH)) != 0) #endif fatal("%s must be owned by root and not group or " "world-writable.", _PATH_PRIVSEP_CHROOT_DIR); } if (test_flag > 1) { if (server_match_spec_complete(connection_info) == 1) parse_server_match_config(&options, connection_info); dump_config(&options); } /* Configuration looks good, so exit if in test mode. */ if (test_flag) exit(0); /* * Clear out any supplemental groups we may have inherited. This * prevents inadvertent creation of files with bad modes (in the * portable version at least, it's certainly possible for PAM * to create a file, and we can't control the code in every * module which might be used). */ if (setgroups(0, NULL) < 0) debug("setgroups() failed: %.200s", strerror(errno)); if (rexec_flag) { rexec_argv = xcalloc(rexec_argc + 2, sizeof(char *)); for (i = 0; i < rexec_argc; i++) { debug("rexec_argv[%d]='%s'", i, saved_argv[i]); rexec_argv[i] = saved_argv[i]; } rexec_argv[rexec_argc] = "-R"; rexec_argv[rexec_argc + 1] = NULL; } /* Ensure that umask disallows at least group and world write */ new_umask = umask(0077) | 0022; (void) umask(new_umask); /* Initialize the log (it is reinitialized below in case we forked). */ if (debug_flag && (!inetd_flag || rexeced_flag)) log_stderr = 1; log_init(__progname, options.log_level, options.log_facility, log_stderr); /* * If not in debugging mode, and not started from inetd, disconnect * from the controlling terminal, and fork. The original process * exits. */ if (!(debug_flag || inetd_flag || no_daemon_flag)) { #ifdef TIOCNOTTY int fd; #endif /* TIOCNOTTY */ if (daemon(0, 0) < 0) fatal("daemon() failed: %.200s", strerror(errno)); /* Disconnect from the controlling tty. */ #ifdef TIOCNOTTY fd = open(_PATH_TTY, O_RDWR | O_NOCTTY); if (fd >= 0) { (void) ioctl(fd, TIOCNOTTY, NULL); close(fd); } #endif /* TIOCNOTTY */ } /* Reinitialize the log (because of the fork above). */ log_init(__progname, options.log_level, options.log_facility, log_stderr); /* Avoid killing the process in high-pressure swapping environments. */ if (!inetd_flag && madvise(NULL, 0, MADV_PROTECT) != 0) debug("madvise(): %.200s", strerror(errno)); /* Chdir to the root directory so that the current disk can be unmounted if desired. */ if (chdir("/") == -1) error("chdir(\"/\"): %s", strerror(errno)); /* ignore SIGPIPE */ signal(SIGPIPE, SIG_IGN); /* Get a connection, either from inetd or a listening TCP socket */ if (inetd_flag) { server_accept_inetd(&sock_in, &sock_out); } else { platform_pre_listen(); server_listen(); if (options.protocol & SSH_PROTO_1) generate_ephemeral_server_key(); signal(SIGHUP, sighup_handler); signal(SIGCHLD, main_sigchld_handler); signal(SIGTERM, sigterm_handler); signal(SIGQUIT, sigterm_handler); /* * Write out the pid file after the sigterm handler * is setup and the listen sockets are bound */ if (options.pid_file != NULL && !debug_flag) { FILE *f = fopen(options.pid_file, "w"); if (f == NULL) { error("Couldn't create pid file \"%s\": %s", options.pid_file, strerror(errno)); } else { fprintf(f, "%ld\n", (long) getpid()); fclose(f); } } /* Accept a connection and return in a forked child */ server_accept_loop(&sock_in, &sock_out, &newsock, config_s); } /* This is the child processing a new connection. */ setproctitle("%s", "[accepted]"); /* * Create a new session and process group since the 4.4BSD * setlogin() affects the entire process group. We don't * want the child to be able to affect the parent. */ #if !defined(SSHD_ACQUIRES_CTTY) /* * If setsid is called, on some platforms sshd will later acquire a * controlling terminal which will result in "could not set * controlling tty" errors. */ if (!debug_flag && !inetd_flag && setsid() < 0) error("setsid: %.100s", strerror(errno)); #endif if (rexec_flag) { int fd; debug("rexec start in %d out %d newsock %d pipe %d sock %d", sock_in, sock_out, newsock, startup_pipe, config_s[0]); dup2(newsock, STDIN_FILENO); dup2(STDIN_FILENO, STDOUT_FILENO); if (startup_pipe == -1) close(REEXEC_STARTUP_PIPE_FD); else if (startup_pipe != REEXEC_STARTUP_PIPE_FD) { dup2(startup_pipe, REEXEC_STARTUP_PIPE_FD); close(startup_pipe); startup_pipe = REEXEC_STARTUP_PIPE_FD; } dup2(config_s[1], REEXEC_CONFIG_PASS_FD); close(config_s[1]); execv(rexec_argv[0], rexec_argv); /* Reexec has failed, fall back and continue */ error("rexec of %s failed: %s", rexec_argv[0], strerror(errno)); recv_rexec_state(REEXEC_CONFIG_PASS_FD, NULL); log_init(__progname, options.log_level, options.log_facility, log_stderr); /* Clean up fds */ close(REEXEC_CONFIG_PASS_FD); newsock = sock_out = sock_in = dup(STDIN_FILENO); if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { dup2(fd, STDIN_FILENO); dup2(fd, STDOUT_FILENO); if (fd > STDERR_FILENO) close(fd); } debug("rexec cleanup in %d out %d newsock %d pipe %d sock %d", sock_in, sock_out, newsock, startup_pipe, config_s[0]); } /* Executed child processes don't need these. */ fcntl(sock_out, F_SETFD, FD_CLOEXEC); fcntl(sock_in, F_SETFD, FD_CLOEXEC); /* * Disable the key regeneration alarm. We will not regenerate the * key since we are no longer in a position to give it to anyone. We * will not restart on SIGHUP since it no longer makes sense. */ alarm(0); signal(SIGALRM, SIG_DFL); signal(SIGHUP, SIG_DFL); signal(SIGTERM, SIG_DFL); signal(SIGQUIT, SIG_DFL); signal(SIGCHLD, SIG_DFL); signal(SIGINT, SIG_DFL); #ifdef __FreeBSD__ /* * Initialize the resolver. This may not happen automatically * before privsep chroot(). */ if ((_res.options & RES_INIT) == 0) { debug("res_init()"); res_init(); } #ifdef GSSAPI /* * Force GSS-API to parse its configuration and load any * mechanism plugins. */ { gss_OID_set mechs; OM_uint32 minor_status; gss_indicate_mechs(&minor_status, &mechs); gss_release_oid_set(&minor_status, &mechs); } #endif #endif /* * Register our connection. This turns encryption off because we do * not have a key. */ packet_set_connection(sock_in, sock_out); packet_set_server(); /* Set SO_KEEPALIVE if requested. */ if (options.tcp_keep_alive && packet_connection_is_on_socket() && setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on)) < 0) error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); if ((remote_port = get_remote_port()) < 0) { debug("get_remote_port failed"); cleanup_exit(255); } /* * We use get_canonical_hostname with usedns = 0 instead of * get_remote_ipaddr here so IP options will be checked. */ (void) get_canonical_hostname(0); /* * The rest of the code depends on the fact that * get_remote_ipaddr() caches the remote ip, even if * the socket goes away. */ remote_ip = get_remote_ipaddr(); #ifdef SSH_AUDIT_EVENTS audit_connection_from(remote_ip, remote_port); #endif #ifdef LIBWRAP allow_severity = options.log_facility|LOG_INFO; deny_severity = options.log_facility|LOG_WARNING; /* Check whether logins are denied from this host. */ if (packet_connection_is_on_socket()) { struct request_info req; request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, 0); fromhost(&req); if (!hosts_access(&req)) { debug("Connection refused by tcp wrapper"); refuse(&req); /* NOTREACHED */ fatal("libwrap refuse returns"); } } #endif /* LIBWRAP */ /* Log the connection. */ laddr = get_local_ipaddr(sock_in); verbose("Connection from %s port %d on %s port %d", remote_ip, remote_port, laddr, get_local_port()); free(laddr); /* * We don't want to listen forever unless the other side * successfully authenticates itself. So we set up an alarm which is * cleared after successful authentication. A limit of zero * indicates no limit. Note that we don't set the alarm in debugging * mode; it is just annoying to have the server exit just when you * are about to discover the bug. */ signal(SIGALRM, grace_alarm_handler); if (!debug_flag) alarm(options.login_grace_time); sshd_exchange_identification(sock_in, sock_out); /* In inetd mode, generate ephemeral key only for proto 1 connections */ if (!compat20 && inetd_flag && sensitive_data.server_key == NULL) generate_ephemeral_server_key(); packet_set_nonblocking(); /* allocate authentication context */ authctxt = xcalloc(1, sizeof(*authctxt)); authctxt->loginmsg = &loginmsg; /* XXX global for cleanup, access from other modules */ the_authctxt = authctxt; /* prepare buffer to collect messages to display to user after login */ buffer_init(&loginmsg); auth_debug_reset(); + BLACKLIST_INIT(); + if (use_privsep) { if (privsep_preauth(authctxt) == 1) goto authenticated; } else if (compat20 && have_agent) { if ((r = ssh_get_authentication_socket(&auth_sock)) != 0) { error("Unable to get agent socket: %s", ssh_err(r)); have_agent = 0; } } /* perform the key exchange */ /* authenticate user and start session */ if (compat20) { do_ssh2_kex(); do_authentication2(authctxt); } else { #ifdef WITH_SSH1 do_ssh1_kex(); do_authentication(authctxt); #else fatal("ssh1 not supported"); #endif } /* * If we use privilege separation, the unprivileged child transfers * the current keystate and exits */ if (use_privsep) { mm_send_keystate(pmonitor); exit(0); } authenticated: /* * Cancel the alarm we set to limit the time taken for * authentication. */ alarm(0); signal(SIGALRM, SIG_DFL); authctxt->authenticated = 1; if (startup_pipe != -1) { close(startup_pipe); startup_pipe = -1; } #ifdef SSH_AUDIT_EVENTS audit_event(SSH_AUTH_SUCCESS); #endif #ifdef GSSAPI if (options.gss_authentication) { temporarily_use_uid(authctxt->pw); ssh_gssapi_storecreds(); restore_uid(); } #endif #ifdef USE_PAM if (options.use_pam) { do_pam_setcred(1); do_pam_session(); } #endif /* * In privilege separation, we fork another child and prepare * file descriptor passing. */ if (use_privsep) { privsep_postauth(authctxt); /* the monitor process [priv] will not return */ if (!compat20) destroy_sensitive_data(); } packet_set_timeout(options.client_alive_interval, options.client_alive_count_max); /* Try to send all our hostkeys to the client */ if (compat20) notify_hostkeys(active_state); /* Start session. */ do_authenticated(authctxt); /* The connection has been terminated. */ packet_get_bytes(&ibytes, &obytes); verbose("Transferred: sent %llu, received %llu bytes", (unsigned long long)obytes, (unsigned long long)ibytes); verbose("Closing connection to %.500s port %d", remote_ip, remote_port); #ifdef USE_PAM if (options.use_pam) finish_pam(); #endif /* USE_PAM */ #ifdef SSH_AUDIT_EVENTS PRIVSEP(audit_event(SSH_CONNECTION_CLOSE)); #endif packet_close(); if (use_privsep) mm_terminate(); exit(0); } #ifdef WITH_SSH1 /* * Decrypt session_key_int using our private server key and private host key * (key with larger modulus first). */ int ssh1_session_key(BIGNUM *session_key_int) { int rsafail = 0; if (BN_cmp(sensitive_data.server_key->rsa->n, sensitive_data.ssh1_host_key->rsa->n) > 0) { /* Server key has bigger modulus. */ if (BN_num_bits(sensitive_data.server_key->rsa->n) < BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) { fatal("do_connection: %s: " "server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d", get_remote_ipaddr(), BN_num_bits(sensitive_data.server_key->rsa->n), BN_num_bits(sensitive_data.ssh1_host_key->rsa->n), SSH_KEY_BITS_RESERVED); } if (rsa_private_decrypt(session_key_int, session_key_int, sensitive_data.server_key->rsa) != 0) rsafail++; if (rsa_private_decrypt(session_key_int, session_key_int, sensitive_data.ssh1_host_key->rsa) != 0) rsafail++; } else { /* Host key has bigger modulus (or they are equal). */ if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) < BN_num_bits(sensitive_data.server_key->rsa->n) + SSH_KEY_BITS_RESERVED) { fatal("do_connection: %s: " "host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d", get_remote_ipaddr(), BN_num_bits(sensitive_data.ssh1_host_key->rsa->n), BN_num_bits(sensitive_data.server_key->rsa->n), SSH_KEY_BITS_RESERVED); } if (rsa_private_decrypt(session_key_int, session_key_int, sensitive_data.ssh1_host_key->rsa) != 0) rsafail++; if (rsa_private_decrypt(session_key_int, session_key_int, sensitive_data.server_key->rsa) != 0) rsafail++; } return (rsafail); } /* * SSH1 key exchange */ static void do_ssh1_kex(void) { int i, len; int rsafail = 0; BIGNUM *session_key_int, *fake_key_int, *real_key_int; u_char session_key[SSH_SESSION_KEY_LENGTH]; u_char fake_key_bytes[4096 / 8]; size_t fake_key_len; u_char cookie[8]; u_int cipher_type, auth_mask, protocol_flags; /* * Generate check bytes that the client must send back in the user * packet in order for it to be accepted; this is used to defy ip * spoofing attacks. Note that this only works against somebody * doing IP spoofing from a remote machine; any machine on the local * network can still see outgoing packets and catch the random * cookie. This only affects rhosts authentication, and this is one * of the reasons why it is inherently insecure. */ arc4random_buf(cookie, sizeof(cookie)); /* * Send our public key. We include in the packet 64 bits of random * data that must be matched in the reply in order to prevent IP * spoofing. */ packet_start(SSH_SMSG_PUBLIC_KEY); for (i = 0; i < 8; i++) packet_put_char(cookie[i]); /* Store our public server RSA key. */ packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n)); packet_put_bignum(sensitive_data.server_key->rsa->e); packet_put_bignum(sensitive_data.server_key->rsa->n); /* Store our public host RSA key. */ packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n)); packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e); packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n); /* Put protocol flags. */ packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN); /* Declare which ciphers we support. */ packet_put_int(cipher_mask_ssh1(0)); /* Declare supported authentication types. */ auth_mask = 0; if (options.rhosts_rsa_authentication) auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA; if (options.rsa_authentication) auth_mask |= 1 << SSH_AUTH_RSA; if (options.challenge_response_authentication == 1) auth_mask |= 1 << SSH_AUTH_TIS; if (options.password_authentication) auth_mask |= 1 << SSH_AUTH_PASSWORD; packet_put_int(auth_mask); /* Send the packet and wait for it to be sent. */ packet_send(); packet_write_wait(); debug("Sent %d bit server key and %d bit host key.", BN_num_bits(sensitive_data.server_key->rsa->n), BN_num_bits(sensitive_data.ssh1_host_key->rsa->n)); /* Read clients reply (cipher type and session key). */ packet_read_expect(SSH_CMSG_SESSION_KEY); /* Get cipher type and check whether we accept this. */ cipher_type = packet_get_char(); if (!(cipher_mask_ssh1(0) & (1 << cipher_type))) packet_disconnect("Warning: client selects unsupported cipher."); /* Get check bytes from the packet. These must match those we sent earlier with the public key packet. */ for (i = 0; i < 8; i++) if (cookie[i] != packet_get_char()) packet_disconnect("IP Spoofing check bytes do not match."); debug("Encryption type: %.200s", cipher_name(cipher_type)); /* Get the encrypted integer. */ if ((real_key_int = BN_new()) == NULL) fatal("do_ssh1_kex: BN_new failed"); packet_get_bignum(real_key_int); protocol_flags = packet_get_int(); packet_set_protocol_flags(protocol_flags); packet_check_eom(); /* Setup a fake key in case RSA decryption fails */ if ((fake_key_int = BN_new()) == NULL) fatal("do_ssh1_kex: BN_new failed"); fake_key_len = BN_num_bytes(real_key_int); if (fake_key_len > sizeof(fake_key_bytes)) fake_key_len = sizeof(fake_key_bytes); arc4random_buf(fake_key_bytes, fake_key_len); if (BN_bin2bn(fake_key_bytes, fake_key_len, fake_key_int) == NULL) fatal("do_ssh1_kex: BN_bin2bn failed"); /* Decrypt real_key_int using host/server keys */ rsafail = PRIVSEP(ssh1_session_key(real_key_int)); /* If decryption failed, use the fake key. Else, the real key. */ if (rsafail) session_key_int = fake_key_int; else session_key_int = real_key_int; /* * Extract session key from the decrypted integer. The key is in the * least significant 256 bits of the integer; the first byte of the * key is in the highest bits. */ (void) BN_mask_bits(session_key_int, sizeof(session_key) * 8); len = BN_num_bytes(session_key_int); if (len < 0 || (u_int)len > sizeof(session_key)) { error("do_ssh1_kex: bad session key len from %s: " "session_key_int %d > sizeof(session_key) %lu", get_remote_ipaddr(), len, (u_long)sizeof(session_key)); rsafail++; } else { explicit_bzero(session_key, sizeof(session_key)); BN_bn2bin(session_key_int, session_key + sizeof(session_key) - len); derive_ssh1_session_id( sensitive_data.ssh1_host_key->rsa->n, sensitive_data.server_key->rsa->n, cookie, session_id); /* * Xor the first 16 bytes of the session key with the * session id. */ for (i = 0; i < 16; i++) session_key[i] ^= session_id[i]; } /* Destroy the private and public keys. No longer. */ destroy_sensitive_data(); if (use_privsep) mm_ssh1_session_id(session_id); /* Destroy the decrypted integer. It is no longer needed. */ BN_clear_free(real_key_int); BN_clear_free(fake_key_int); /* Set the session key. From this on all communications will be encrypted. */ packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type); /* Destroy our copy of the session key. It is no longer needed. */ explicit_bzero(session_key, sizeof(session_key)); debug("Received session key; encryption turned on."); /* Send an acknowledgment packet. Note that this packet is sent encrypted. */ packet_start(SSH_SMSG_SUCCESS); packet_send(); packet_write_wait(); } #endif int sshd_hostkey_sign(Key *privkey, Key *pubkey, u_char **signature, size_t *slen, const u_char *data, size_t dlen, const char *alg, u_int flag) { int r; u_int xxx_slen, xxx_dlen = dlen; if (privkey) { if (PRIVSEP(key_sign(privkey, signature, &xxx_slen, data, xxx_dlen, alg) < 0)) fatal("%s: key_sign failed", __func__); if (slen) *slen = xxx_slen; } else if (use_privsep) { if (mm_key_sign(pubkey, signature, &xxx_slen, data, xxx_dlen, alg) < 0) fatal("%s: pubkey_sign failed", __func__); if (slen) *slen = xxx_slen; } else { if ((r = ssh_agent_sign(auth_sock, pubkey, signature, slen, data, dlen, alg, datafellows)) != 0) fatal("%s: ssh_agent_sign failed: %s", __func__, ssh_err(r)); } return 0; } /* SSH2 key exchange */ static void do_ssh2_kex(void) { char *myproposal[PROPOSAL_MAX] = { KEX_SERVER }; struct kex *kex; int r; myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal( options.kex_algorithms); myproposal[PROPOSAL_ENC_ALGS_CTOS] = compat_cipher_proposal( options.ciphers); myproposal[PROPOSAL_ENC_ALGS_STOC] = compat_cipher_proposal( options.ciphers); myproposal[PROPOSAL_MAC_ALGS_CTOS] = myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; if (options.compression == COMP_NONE) { myproposal[PROPOSAL_COMP_ALGS_CTOS] = myproposal[PROPOSAL_COMP_ALGS_STOC] = "none"; } else if (options.compression == COMP_DELAYED) { myproposal[PROPOSAL_COMP_ALGS_CTOS] = myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com"; } if (options.rekey_limit || options.rekey_interval) packet_set_rekey_limits(options.rekey_limit, (time_t)options.rekey_interval); myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = compat_pkalg_proposal( list_hostkey_types()); /* start key exchange */ if ((r = kex_setup(active_state, myproposal)) != 0) fatal("kex_setup: %s", ssh_err(r)); kex = active_state->kex; #ifdef WITH_OPENSSL kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; # ifdef OPENSSL_HAS_ECC kex->kex[KEX_ECDH_SHA2] = kexecdh_server; # endif #endif kex->kex[KEX_C25519_SHA256] = kexc25519_server; kex->server = 1; kex->client_version_string=client_version_string; kex->server_version_string=server_version_string; kex->load_host_public_key=&get_hostkey_public_by_type; kex->load_host_private_key=&get_hostkey_private_by_type; kex->host_key_index=&get_hostkey_index; kex->sign = sshd_hostkey_sign; dispatch_run(DISPATCH_BLOCK, &kex->done, active_state); session_id2 = kex->session_id; session_id2_len = kex->session_id_len; #ifdef DEBUG_KEXDH /* send 1st encrypted/maced/compressed message */ packet_start(SSH2_MSG_IGNORE); packet_put_cstring("markus"); packet_send(); packet_write_wait(); #endif debug("KEX done"); } /* server specific fatal cleanup */ void cleanup_exit(int i) { if (the_authctxt) { do_cleanup(the_authctxt); if (use_privsep && privsep_is_preauth && pmonitor != NULL && pmonitor->m_pid > 1) { debug("Killing privsep child %d", pmonitor->m_pid); if (kill(pmonitor->m_pid, SIGKILL) != 0 && errno != ESRCH) error("%s: kill(%d): %s", __func__, pmonitor->m_pid, strerror(errno)); } } #ifdef SSH_AUDIT_EVENTS /* done after do_cleanup so it can cancel the PAM auth 'thread' */ if (!use_privsep || mm_is_monitor()) audit_event(SSH_CONNECTION_ABANDON); #endif _exit(i); } diff --git a/crypto/openssh/sshd_config b/crypto/openssh/sshd_config index 6ea0b0885732..a842e6efef9a 100644 --- a/crypto/openssh/sshd_config +++ b/crypto/openssh/sshd_config @@ -1,136 +1,137 @@ # $OpenBSD: sshd_config,v 1.98 2016/02/17 05:29:04 djm Exp $ # $FreeBSD$ # This is the sshd server system-wide configuration file. See # sshd_config(5) for more information. # This sshd was compiled with PATH=/usr/bin:/bin:/usr/sbin:/sbin # The strategy used for options in the default sshd_config shipped with # OpenSSH is to specify options with their default value where # possible, but leave them commented. Uncommented options override the # default value. # Note that some of FreeBSD's defaults differ from OpenBSD's, and # FreeBSD has a few additional options. #Port 22 #AddressFamily any #ListenAddress 0.0.0.0 #ListenAddress :: # The default requires explicit activation of protocol 1 #Protocol 2 # HostKey for protocol version 1 #HostKey /etc/ssh/ssh_host_key # HostKeys for protocol version 2 #HostKey /etc/ssh/ssh_host_rsa_key #HostKey /etc/ssh/ssh_host_dsa_key #HostKey /etc/ssh/ssh_host_ecdsa_key #HostKey /etc/ssh/ssh_host_ed25519_key # Lifetime and size of ephemeral version 1 server key #KeyRegenerationInterval 1h #ServerKeyBits 1024 # Ciphers and keying #RekeyLimit default none # Logging # obsoletes QuietMode and FascistLogging #SyslogFacility AUTH #LogLevel INFO # Authentication: #LoginGraceTime 2m #PermitRootLogin no #StrictModes yes #MaxAuthTries 6 #MaxSessions 10 #RSAAuthentication yes #PubkeyAuthentication yes # The default is to check both .ssh/authorized_keys and .ssh/authorized_keys2 #AuthorizedKeysFile .ssh/authorized_keys .ssh/authorized_keys2 #AuthorizedPrincipalsFile none #AuthorizedKeysCommand none #AuthorizedKeysCommandUser nobody # For this to work you will also need host keys in /etc/ssh/ssh_known_hosts #RhostsRSAAuthentication no # similar for protocol version 2 #HostbasedAuthentication no # Change to yes if you don't trust ~/.ssh/known_hosts for # RhostsRSAAuthentication and HostbasedAuthentication #IgnoreUserKnownHosts no # Don't read the user's ~/.rhosts and ~/.shosts files #IgnoreRhosts yes # Change to yes to enable built-in password authentication. #PasswordAuthentication no #PermitEmptyPasswords no # Change to no to disable PAM authentication #ChallengeResponseAuthentication yes # Kerberos options #KerberosAuthentication no #KerberosOrLocalPasswd yes #KerberosTicketCleanup yes #KerberosGetAFSToken no # GSSAPI options #GSSAPIAuthentication no #GSSAPICleanupCredentials yes # Set this to 'no' to disable PAM authentication, account processing, # and session processing. If this is enabled, PAM authentication will # be allowed through the ChallengeResponseAuthentication and # PasswordAuthentication. Depending on your PAM configuration, # PAM authentication via ChallengeResponseAuthentication may bypass # the setting of "PermitRootLogin without-password". # If you just want the PAM account and session checks to run without # PAM authentication, then enable this but set PasswordAuthentication # and ChallengeResponseAuthentication to 'no'. #UsePAM yes #AllowAgentForwarding yes #AllowTcpForwarding yes #GatewayPorts no #X11Forwarding yes #X11DisplayOffset 10 #X11UseLocalhost yes #PermitTTY yes #PrintMotd yes #PrintLastLog yes #TCPKeepAlive yes #UseLogin no #UsePrivilegeSeparation sandbox #PermitUserEnvironment no #Compression delayed #ClientAliveInterval 0 #ClientAliveCountMax 3 #UseDNS yes #PidFile /var/run/sshd.pid #MaxStartups 10:30:100 #PermitTunnel no #ChrootDirectory none +#UseBlacklist no #VersionAddendum FreeBSD-20160310 # no default banner path #Banner none # override default of no subsystems Subsystem sftp /usr/libexec/sftp-server # Example of overriding settings on a per-user basis #Match User anoncvs # X11Forwarding no # AllowTcpForwarding no # PermitTTY no # ForceCommand cvs server diff --git a/crypto/openssh/sshd_config.5 b/crypto/openssh/sshd_config.5 index 78531214a1f9..54c95ad74220 100644 --- a/crypto/openssh/sshd_config.5 +++ b/crypto/openssh/sshd_config.5 @@ -1,1767 +1,1776 @@ .\" .\" Author: Tatu Ylonen .\" Copyright (c) 1995 Tatu Ylonen , Espoo, Finland .\" All rights reserved .\" .\" As far as I am concerned, the code I have written for this software .\" can be used freely for any purpose. Any derived versions of this .\" software must be clearly marked as such, and if the derived work is .\" incompatible with the protocol description in the RFC file, it must be .\" called by a name other than "ssh" or "Secure Shell". .\" .\" Copyright (c) 1999,2000 Markus Friedl. All rights reserved. .\" Copyright (c) 1999 Aaron Campbell. All rights reserved. .\" Copyright (c) 1999 Theo de Raadt. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR .\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES .\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. .\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, .\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, .\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY .\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" .\" $OpenBSD: sshd_config.5,v 1.220 2016/02/17 08:57:34 djm Exp $ .\" $FreeBSD$ .Dd $Mdocdate: February 17 2016 $ .Dt SSHD_CONFIG 5 .Os .Sh NAME .Nm sshd_config .Nd OpenSSH SSH daemon configuration file .Sh SYNOPSIS .Nm /etc/ssh/sshd_config .Sh DESCRIPTION .Xr sshd 8 reads configuration data from .Pa /etc/ssh/sshd_config (or the file specified with .Fl f on the command line). The file contains keyword-argument pairs, one per line. Lines starting with .Ql # and empty lines are interpreted as comments. Arguments may optionally be enclosed in double quotes .Pq \&" in order to represent arguments containing spaces. .Pp The possible keywords and their meanings are as follows (note that keywords are case-insensitive and arguments are case-sensitive): .Bl -tag -width Ds .It Cm AcceptEnv Specifies what environment variables sent by the client will be copied into the session's .Xr environ 7 . See .Cm SendEnv in .Xr ssh_config 5 for how to configure the client. The .Ev TERM environment variable is always sent whenever the client requests a pseudo-terminal as it is required by the protocol. Variables are specified by name, which may contain the wildcard characters .Ql * and .Ql \&? . Multiple environment variables may be separated by whitespace or spread across multiple .Cm AcceptEnv directives. Be warned that some environment variables could be used to bypass restricted user environments. For this reason, care should be taken in the use of this directive. The default is not to accept any environment variables. .It Cm AddressFamily Specifies which address family should be used by .Xr sshd 8 . Valid arguments are .Dq any , .Dq inet (use IPv4 only), or .Dq inet6 (use IPv6 only). The default is .Dq any . .It Cm AllowAgentForwarding Specifies whether .Xr ssh-agent 1 forwarding is permitted. The default is .Dq yes . Note that disabling agent forwarding does not improve security unless users are also denied shell access, as they can always install their own forwarders. .It Cm AllowGroups This keyword can be followed by a list of group name patterns, separated by spaces. If specified, login is allowed only for users whose primary group or supplementary group list matches one of the patterns. Only group names are valid; a numerical group ID is not recognized. By default, login is allowed for all groups. The allow/deny directives are processed in the following order: .Cm DenyUsers , .Cm AllowUsers , .Cm DenyGroups , and finally .Cm AllowGroups . .Pp See PATTERNS in .Xr ssh_config 5 for more information on patterns. .It Cm AllowTcpForwarding Specifies whether TCP forwarding is permitted. The available options are .Dq yes or .Dq all to allow TCP forwarding, .Dq no to prevent all TCP forwarding, .Dq local to allow local (from the perspective of .Xr ssh 1 ) forwarding only or .Dq remote to allow remote forwarding only. The default is .Dq yes . Note that disabling TCP forwarding does not improve security unless users are also denied shell access, as they can always install their own forwarders. .It Cm AllowStreamLocalForwarding Specifies whether StreamLocal (Unix-domain socket) forwarding is permitted. The available options are .Dq yes or .Dq all to allow StreamLocal forwarding, .Dq no to prevent all StreamLocal forwarding, .Dq local to allow local (from the perspective of .Xr ssh 1 ) forwarding only or .Dq remote to allow remote forwarding only. The default is .Dq yes . Note that disabling StreamLocal forwarding does not improve security unless users are also denied shell access, as they can always install their own forwarders. .It Cm AllowUsers This keyword can be followed by a list of user name patterns, separated by spaces. If specified, login is allowed only for user names that match one of the patterns. Only user names are valid; a numerical user ID is not recognized. By default, login is allowed for all users. If the pattern takes the form USER@HOST then USER and HOST are separately checked, restricting logins to particular users from particular hosts. The allow/deny directives are processed in the following order: .Cm DenyUsers , .Cm AllowUsers , .Cm DenyGroups , and finally .Cm AllowGroups . .Pp See PATTERNS in .Xr ssh_config 5 for more information on patterns. .It Cm AuthenticationMethods Specifies the authentication methods that must be successfully completed for a user to be granted access. This option must be followed by one or more comma-separated lists of authentication method names. Successful authentication requires completion of every method in at least one of these lists. .Pp For example, an argument of .Dq publickey,password publickey,keyboard-interactive would require the user to complete public key authentication, followed by either password or keyboard interactive authentication. Only methods that are next in one or more lists are offered at each stage, so for this example, it would not be possible to attempt password or keyboard-interactive authentication before public key. .Pp For keyboard interactive authentication it is also possible to restrict authentication to a specific device by appending a colon followed by the device identifier .Dq bsdauth , .Dq pam , or .Dq skey , depending on the server configuration. For example, .Dq keyboard-interactive:bsdauth would restrict keyboard interactive authentication to the .Dq bsdauth device. .Pp If the .Dq publickey method is listed more than once, .Xr sshd 8 verifies that keys that have been used successfully are not reused for subsequent authentications. For example, an .Cm AuthenticationMethods of .Dq publickey,publickey will require successful authentication using two different public keys. .Pp This option will yield a fatal error if enabled if protocol 1 is also enabled. Note that each authentication method listed should also be explicitly enabled in the configuration. The default is not to require multiple authentication; successful completion of a single authentication method is sufficient. .It Cm AuthorizedKeysCommand Specifies a program to be used to look up the user's public keys. The program must be owned by root, not writable by group or others and specified by an absolute path. .Pp Arguments to .Cm AuthorizedKeysCommand may be provided using the following tokens, which will be expanded at runtime: %% is replaced by a literal '%', %u is replaced by the username being authenticated, %h is replaced by the home directory of the user being authenticated, %t is replaced with the key type offered for authentication, %f is replaced with the fingerprint of the key, and %k is replaced with the key being offered for authentication. If no arguments are specified then the username of the target user will be supplied. .Pp The program should produce on standard output zero or more lines of authorized_keys output (see AUTHORIZED_KEYS in .Xr sshd 8 ) . If a key supplied by AuthorizedKeysCommand does not successfully authenticate and authorize the user then public key authentication continues using the usual .Cm AuthorizedKeysFile files. By default, no AuthorizedKeysCommand is run. .It Cm AuthorizedKeysCommandUser Specifies the user under whose account the AuthorizedKeysCommand is run. It is recommended to use a dedicated user that has no other role on the host than running authorized keys commands. If .Cm AuthorizedKeysCommand is specified but .Cm AuthorizedKeysCommandUser is not, then .Xr sshd 8 will refuse to start. .It Cm AuthorizedKeysFile Specifies the file that contains the public keys that can be used for user authentication. The format is described in the AUTHORIZED_KEYS FILE FORMAT section of .Xr sshd 8 . .Cm AuthorizedKeysFile may contain tokens of the form %T which are substituted during connection setup. The following tokens are defined: %% is replaced by a literal '%', %h is replaced by the home directory of the user being authenticated, and %u is replaced by the username of that user. After expansion, .Cm AuthorizedKeysFile is taken to be an absolute path or one relative to the user's home directory. Multiple files may be listed, separated by whitespace. Alternately this option may be set to .Dq none to skip checking for user keys in files. The default is .Dq .ssh/authorized_keys .ssh/authorized_keys2 . .It Cm AuthorizedPrincipalsCommand Specifies a program to be used to generate the list of allowed certificate principals as per .Cm AuthorizedPrincipalsFile . The program must be owned by root, not writable by group or others and specified by an absolute path. .Pp Arguments to .Cm AuthorizedPrincipalsCommand may be provided using the following tokens, which will be expanded at runtime: %% is replaced by a literal '%', %u is replaced by the username being authenticated and %h is replaced by the home directory of the user being authenticated. .Pp The program should produce on standard output zero or more lines of .Cm AuthorizedPrincipalsFile output. If either .Cm AuthorizedPrincipalsCommand or .Cm AuthorizedPrincipalsFile is specified, then certificates offered by the client for authentication must contain a principal that is listed. By default, no AuthorizedPrincipalsCommand is run. .It Cm AuthorizedPrincipalsCommandUser Specifies the user under whose account the AuthorizedPrincipalsCommand is run. It is recommended to use a dedicated user that has no other role on the host than running authorized principals commands. If .Cm AuthorizedPrincipalsCommand is specified but .Cm AuthorizedPrincipalsCommandUser is not, then .Xr sshd 8 will refuse to start. .It Cm AuthorizedPrincipalsFile Specifies a file that lists principal names that are accepted for certificate authentication. When using certificates signed by a key listed in .Cm TrustedUserCAKeys , this file lists names, one of which must appear in the certificate for it to be accepted for authentication. Names are listed one per line preceded by key options (as described in AUTHORIZED_KEYS FILE FORMAT in .Xr sshd 8 ) . Empty lines and comments starting with .Ql # are ignored. .Pp .Cm AuthorizedPrincipalsFile may contain tokens of the form %T which are substituted during connection setup. The following tokens are defined: %% is replaced by a literal '%', %h is replaced by the home directory of the user being authenticated, and %u is replaced by the username of that user. After expansion, .Cm AuthorizedPrincipalsFile is taken to be an absolute path or one relative to the user's home directory. .Pp The default is .Dq none , i.e. not to use a principals file \(en in this case, the username of the user must appear in a certificate's principals list for it to be accepted. Note that .Cm AuthorizedPrincipalsFile is only used when authentication proceeds using a CA listed in .Cm TrustedUserCAKeys and is not consulted for certification authorities trusted via .Pa ~/.ssh/authorized_keys , though the .Cm principals= key option offers a similar facility (see .Xr sshd 8 for details). .It Cm Banner The contents of the specified file are sent to the remote user before authentication is allowed. If the argument is .Dq none then no banner is displayed. By default, no banner is displayed. .It Cm ChallengeResponseAuthentication Specifies whether challenge-response authentication is allowed (e.g. via PAM or through authentication styles supported in .Xr login.conf 5 ) The default is .Dq yes . .It Cm ChrootDirectory Specifies the pathname of a directory to .Xr chroot 2 to after authentication. At session startup .Xr sshd 8 checks that all components of the pathname are root-owned directories which are not writable by any other user or group. After the chroot, .Xr sshd 8 changes the working directory to the user's home directory. .Pp The pathname may contain the following tokens that are expanded at runtime once the connecting user has been authenticated: %% is replaced by a literal '%', %h is replaced by the home directory of the user being authenticated, and %u is replaced by the username of that user. .Pp The .Cm ChrootDirectory must contain the necessary files and directories to support the user's session. For an interactive session this requires at least a shell, typically .Xr sh 1 , and basic .Pa /dev nodes such as .Xr null 4 , .Xr zero 4 , .Xr stdin 4 , .Xr stdout 4 , .Xr stderr 4 , and .Xr tty 4 devices. For file transfer sessions using .Dq sftp , no additional configuration of the environment is necessary if the in-process sftp server is used, though sessions which use logging may require .Pa /dev/log inside the chroot directory on some operating systems (see .Xr sftp-server 8 for details). .Pp For safety, it is very important that the directory hierarchy be prevented from modification by other processes on the system (especially those outside the jail). Misconfiguration can lead to unsafe environments which .Xr sshd 8 cannot detect. .Pp The default is .Dq none , indicating not to .Xr chroot 2 . .It Cm Ciphers Specifies the ciphers allowed. Multiple ciphers must be comma-separated. If the specified value begins with a .Sq + character, then the specified ciphers will be appended to the default set instead of replacing them. .Pp The supported ciphers are: .Pp .Bl -item -compact -offset indent .It 3des-cbc .It aes128-cbc .It aes192-cbc .It aes256-cbc .It aes128-ctr .It aes192-ctr .It aes256-ctr .It aes128-gcm@openssh.com .It aes256-gcm@openssh.com .It arcfour .It arcfour128 .It arcfour256 .It blowfish-cbc .It cast128-cbc .It chacha20-poly1305@openssh.com .El .Pp The default is: .Bd -literal -offset indent chacha20-poly1305@openssh.com, aes128-ctr,aes192-ctr,aes256-ctr, aes128-gcm@openssh.com,aes256-gcm@openssh.com, aes128-cbc,aes192-cbc,aes256-cbc .Ed .Pp The list of available ciphers may also be obtained using the .Fl Q option of .Xr ssh 1 with an argument of .Dq cipher . .It Cm ClientAliveCountMax Sets the number of client alive messages (see below) which may be sent without .Xr sshd 8 receiving any messages back from the client. If this threshold is reached while client alive messages are being sent, sshd will disconnect the client, terminating the session. It is important to note that the use of client alive messages is very different from .Cm TCPKeepAlive (below). The client alive messages are sent through the encrypted channel and therefore will not be spoofable. The TCP keepalive option enabled by .Cm TCPKeepAlive is spoofable. The client alive mechanism is valuable when the client or server depend on knowing when a connection has become inactive. .Pp The default value is 3. If .Cm ClientAliveInterval (see below) is set to 15, and .Cm ClientAliveCountMax is left at the default, unresponsive SSH clients will be disconnected after approximately 45 seconds. .It Cm ClientAliveInterval Sets a timeout interval in seconds after which if no data has been received from the client, .Xr sshd 8 will send a message through the encrypted channel to request a response from the client. The default is 0, indicating that these messages will not be sent to the client. .It Cm Compression Specifies whether compression is allowed, or delayed until the user has authenticated successfully. The argument must be .Dq yes , .Dq delayed , or .Dq no . The default is .Dq delayed . .It Cm DenyGroups This keyword can be followed by a list of group name patterns, separated by spaces. Login is disallowed for users whose primary group or supplementary group list matches one of the patterns. Only group names are valid; a numerical group ID is not recognized. By default, login is allowed for all groups. The allow/deny directives are processed in the following order: .Cm DenyUsers , .Cm AllowUsers , .Cm DenyGroups , and finally .Cm AllowGroups . .Pp See PATTERNS in .Xr ssh_config 5 for more information on patterns. .It Cm DenyUsers This keyword can be followed by a list of user name patterns, separated by spaces. Login is disallowed for user names that match one of the patterns. Only user names are valid; a numerical user ID is not recognized. By default, login is allowed for all users. If the pattern takes the form USER@HOST then USER and HOST are separately checked, restricting logins to particular users from particular hosts. The allow/deny directives are processed in the following order: .Cm DenyUsers , .Cm AllowUsers , .Cm DenyGroups , and finally .Cm AllowGroups . .Pp See PATTERNS in .Xr ssh_config 5 for more information on patterns. .It Cm FingerprintHash Specifies the hash algorithm used when logging key fingerprints. Valid options are: .Dq md5 and .Dq sha256 . The default is .Dq sha256 . .It Cm ForceCommand Forces the execution of the command specified by .Cm ForceCommand , ignoring any command supplied by the client and .Pa ~/.ssh/rc if present. The command is invoked by using the user's login shell with the -c option. This applies to shell, command, or subsystem execution. It is most useful inside a .Cm Match block. The command originally supplied by the client is available in the .Ev SSH_ORIGINAL_COMMAND environment variable. Specifying a command of .Dq internal-sftp will force the use of an in-process sftp server that requires no support files when used with .Cm ChrootDirectory . The default is .Dq none . .It Cm GatewayPorts Specifies whether remote hosts are allowed to connect to ports forwarded for the client. By default, .Xr sshd 8 binds remote port forwardings to the loopback address. This prevents other remote hosts from connecting to forwarded ports. .Cm GatewayPorts can be used to specify that sshd should allow remote port forwardings to bind to non-loopback addresses, thus allowing other hosts to connect. The argument may be .Dq no to force remote port forwardings to be available to the local host only, .Dq yes to force remote port forwardings to bind to the wildcard address, or .Dq clientspecified to allow the client to select the address to which the forwarding is bound. The default is .Dq no . .It Cm GSSAPIAuthentication Specifies whether user authentication based on GSSAPI is allowed. The default is .Dq no . .It Cm GSSAPICleanupCredentials Specifies whether to automatically destroy the user's credentials cache on logout. The default is .Dq yes . .It Cm GSSAPIStrictAcceptorCheck Determines whether to be strict about the identity of the GSSAPI acceptor a client authenticates against. If set to .Dq yes then the client must authenticate against the .Pa host service on the current hostname. If set to .Dq no then the client may authenticate against any service key stored in the machine's default store. This facility is provided to assist with operation on multi homed machines. The default is .Dq yes . .It Cm HostbasedAcceptedKeyTypes Specifies the key types that will be accepted for hostbased authentication as a comma-separated pattern list. Alternately if the specified value begins with a .Sq + character, then the specified key types will be appended to the default set instead of replacing them. The default for this option is: .Bd -literal -offset 3n ecdsa-sha2-nistp256-cert-v01@openssh.com, ecdsa-sha2-nistp384-cert-v01@openssh.com, ecdsa-sha2-nistp521-cert-v01@openssh.com, ssh-ed25519-cert-v01@openssh.com, ssh-rsa-cert-v01@openssh.com, ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521, ssh-ed25519,ssh-rsa .Ed .Pp The .Fl Q option of .Xr ssh 1 may be used to list supported key types. .It Cm HostbasedAuthentication Specifies whether rhosts or /etc/hosts.equiv authentication together with successful public key client host authentication is allowed (host-based authentication). The default is .Dq no . .It Cm HostbasedUsesNameFromPacketOnly Specifies whether or not the server will attempt to perform a reverse name lookup when matching the name in the .Pa ~/.shosts , .Pa ~/.rhosts , and .Pa /etc/hosts.equiv files during .Cm HostbasedAuthentication . A setting of .Dq yes means that .Xr sshd 8 uses the name supplied by the client rather than attempting to resolve the name from the TCP connection itself. The default is .Dq no . .It Cm HostCertificate Specifies a file containing a public host certificate. The certificate's public key must match a private host key already specified by .Cm HostKey . The default behaviour of .Xr sshd 8 is not to load any certificates. .It Cm HostKey Specifies a file containing a private host key used by SSH. The default is .Pa /etc/ssh/ssh_host_key for protocol version 1, and .Pa /etc/ssh/ssh_host_dsa_key , .Pa /etc/ssh/ssh_host_ecdsa_key , .Pa /etc/ssh/ssh_host_ed25519_key and .Pa /etc/ssh/ssh_host_rsa_key for protocol version 2. .Pp Note that .Xr sshd 8 will refuse to use a file if it is group/world-accessible and that the .Cm HostKeyAlgorithms option restricts which of the keys are actually used by .Xr sshd 8 . .Pp It is possible to have multiple host key files. .Dq rsa1 keys are used for version 1 and .Dq dsa , .Dq ecdsa , .Dq ed25519 or .Dq rsa are used for version 2 of the SSH protocol. It is also possible to specify public host key files instead. In this case operations on the private key will be delegated to an .Xr ssh-agent 1 . .It Cm HostKeyAgent Identifies the UNIX-domain socket used to communicate with an agent that has access to the private host keys. If .Dq SSH_AUTH_SOCK is specified, the location of the socket will be read from the .Ev SSH_AUTH_SOCK environment variable. .It Cm HostKeyAlgorithms Specifies the host key algorithms that the server offers. The default for this option is: .Bd -literal -offset 3n ecdsa-sha2-nistp256-cert-v01@openssh.com, ecdsa-sha2-nistp384-cert-v01@openssh.com, ecdsa-sha2-nistp521-cert-v01@openssh.com, ssh-ed25519-cert-v01@openssh.com, ssh-rsa-cert-v01@openssh.com, ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521, ssh-ed25519,ssh-rsa .Ed .Pp The list of available key types may also be obtained using the .Fl Q option of .Xr ssh 1 with an argument of .Dq key . .It Cm IgnoreRhosts Specifies that .Pa .rhosts and .Pa .shosts files will not be used in .Cm RhostsRSAAuthentication or .Cm HostbasedAuthentication . .Pp .Pa /etc/hosts.equiv and .Pa /etc/ssh/shosts.equiv are still used. The default is .Dq yes . .It Cm IgnoreUserKnownHosts Specifies whether .Xr sshd 8 should ignore the user's .Pa ~/.ssh/known_hosts during .Cm RhostsRSAAuthentication or .Cm HostbasedAuthentication . The default is .Dq no . .It Cm IPQoS Specifies the IPv4 type-of-service or DSCP class for the connection. Accepted values are .Dq af11 , .Dq af12 , .Dq af13 , .Dq af21 , .Dq af22 , .Dq af23 , .Dq af31 , .Dq af32 , .Dq af33 , .Dq af41 , .Dq af42 , .Dq af43 , .Dq cs0 , .Dq cs1 , .Dq cs2 , .Dq cs3 , .Dq cs4 , .Dq cs5 , .Dq cs6 , .Dq cs7 , .Dq ef , .Dq lowdelay , .Dq throughput , .Dq reliability , or a numeric value. This option may take one or two arguments, separated by whitespace. If one argument is specified, it is used as the packet class unconditionally. If two values are specified, the first is automatically selected for interactive sessions and the second for non-interactive sessions. The default is .Dq lowdelay for interactive sessions and .Dq throughput for non-interactive sessions. .It Cm KbdInteractiveAuthentication Specifies whether to allow keyboard-interactive authentication. The argument to this keyword must be .Dq yes or .Dq no . The default is to use whatever value .Cm ChallengeResponseAuthentication is set to (by default .Dq yes ) . .It Cm KerberosAuthentication Specifies whether the password provided by the user for .Cm PasswordAuthentication will be validated through the Kerberos KDC. To use this option, the server needs a Kerberos servtab which allows the verification of the KDC's identity. The default is .Dq no . .It Cm KerberosGetAFSToken If AFS is active and the user has a Kerberos 5 TGT, attempt to acquire an AFS token before accessing the user's home directory. The default is .Dq no . .It Cm KerberosOrLocalPasswd If password authentication through Kerberos fails then the password will be validated via any additional local mechanism such as .Pa /etc/passwd . The default is .Dq yes . .It Cm KerberosTicketCleanup Specifies whether to automatically destroy the user's ticket cache file on logout. The default is .Dq yes . .It Cm KexAlgorithms Specifies the available KEX (Key Exchange) algorithms. Multiple algorithms must be comma-separated. Alternately if the specified value begins with a .Sq + character, then the specified methods will be appended to the default set instead of replacing them. The supported algorithms are: .Pp .Bl -item -compact -offset indent .It curve25519-sha256@libssh.org .It diffie-hellman-group1-sha1 .It diffie-hellman-group14-sha1 .It diffie-hellman-group-exchange-sha1 .It diffie-hellman-group-exchange-sha256 .It ecdh-sha2-nistp256 .It ecdh-sha2-nistp384 .It ecdh-sha2-nistp521 .El .Pp The default is: .Bd -literal -offset indent curve25519-sha256@libssh.org, ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521, diffie-hellman-group-exchange-sha256, diffie-hellman-group14-sha1 .Ed .Pp The list of available key exchange algorithms may also be obtained using the .Fl Q option of .Xr ssh 1 with an argument of .Dq kex . .It Cm KeyRegenerationInterval In protocol version 1, the ephemeral server key is automatically regenerated after this many seconds (if it has been used). The purpose of regeneration is to prevent decrypting captured sessions by later breaking into the machine and stealing the keys. The key is never stored anywhere. If the value is 0, the key is never regenerated. The default is 3600 (seconds). .It Cm ListenAddress Specifies the local addresses .Xr sshd 8 should listen on. The following forms may be used: .Pp .Bl -item -offset indent -compact .It .Cm ListenAddress .Sm off .Ar host | Ar IPv4_addr | Ar IPv6_addr .Sm on .It .Cm ListenAddress .Sm off .Ar host | Ar IPv4_addr : Ar port .Sm on .It .Cm ListenAddress .Sm off .Oo .Ar host | Ar IPv6_addr Oc : Ar port .Sm on .El .Pp If .Ar port is not specified, sshd will listen on the address and all .Cm Port options specified. The default is to listen on all local addresses. Multiple .Cm ListenAddress options are permitted. .It Cm LoginGraceTime The server disconnects after this time if the user has not successfully logged in. If the value is 0, there is no time limit. The default is 120 seconds. .It Cm LogLevel Gives the verbosity level that is used when logging messages from .Xr sshd 8 . The possible values are: QUIET, FATAL, ERROR, INFO, VERBOSE, DEBUG, DEBUG1, DEBUG2, and DEBUG3. The default is INFO. DEBUG and DEBUG1 are equivalent. DEBUG2 and DEBUG3 each specify higher levels of debugging output. Logging with a DEBUG level violates the privacy of users and is not recommended. .It Cm MACs Specifies the available MAC (message authentication code) algorithms. The MAC algorithm is used for data integrity protection. Multiple algorithms must be comma-separated. If the specified value begins with a .Sq + character, then the specified algorithms will be appended to the default set instead of replacing them. .Pp The algorithms that contain .Dq -etm calculate the MAC after encryption (encrypt-then-mac). These are considered safer and their use recommended. The supported MACs are: .Pp .Bl -item -compact -offset indent .It hmac-md5 .It hmac-md5-96 .It hmac-ripemd160 .It hmac-sha1 .It hmac-sha1-96 .It hmac-sha2-256 .It hmac-sha2-512 .It umac-64@openssh.com .It umac-128@openssh.com .It hmac-md5-etm@openssh.com .It hmac-md5-96-etm@openssh.com .It hmac-ripemd160-etm@openssh.com .It hmac-sha1-etm@openssh.com .It hmac-sha1-96-etm@openssh.com .It hmac-sha2-256-etm@openssh.com .It hmac-sha2-512-etm@openssh.com .It umac-64-etm@openssh.com .It umac-128-etm@openssh.com .El .Pp The default is: .Bd -literal -offset indent umac-64-etm@openssh.com,umac-128-etm@openssh.com, hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com, hmac-sha1-etm@openssh.com, umac-64@openssh.com,umac-128@openssh.com, hmac-sha2-256,hmac-sha2-512,hmac-sha1 .Ed .Pp The list of available MAC algorithms may also be obtained using the .Fl Q option of .Xr ssh 1 with an argument of .Dq mac . .It Cm Match Introduces a conditional block. If all of the criteria on the .Cm Match line are satisfied, the keywords on the following lines override those set in the global section of the config file, until either another .Cm Match line or the end of the file. If a keyword appears in multiple .Cm Match blocks that are satisfied, only the first instance of the keyword is applied. .Pp The arguments to .Cm Match are one or more criteria-pattern pairs or the single token .Cm All which matches all criteria. The available criteria are .Cm User , .Cm Group , .Cm Host , .Cm LocalAddress , .Cm LocalPort , and .Cm Address . The match patterns may consist of single entries or comma-separated lists and may use the wildcard and negation operators described in the PATTERNS section of .Xr ssh_config 5 . .Pp The patterns in an .Cm Address criteria may additionally contain addresses to match in CIDR address/masklen format, e.g.\& .Dq 192.0.2.0/24 or .Dq 3ffe:ffff::/32 . Note that the mask length provided must be consistent with the address - it is an error to specify a mask length that is too long for the address or one with bits set in this host portion of the address. For example, .Dq 192.0.2.0/33 and .Dq 192.0.2.0/8 respectively. .Pp Only a subset of keywords may be used on the lines following a .Cm Match keyword. Available keywords are .Cm AcceptEnv , .Cm AllowAgentForwarding , .Cm AllowGroups , .Cm AllowStreamLocalForwarding , .Cm AllowTcpForwarding , .Cm AllowUsers , .Cm AuthenticationMethods , .Cm AuthorizedKeysCommand , .Cm AuthorizedKeysCommandUser , .Cm AuthorizedKeysFile , .Cm AuthorizedPrincipalsCommand , .Cm AuthorizedPrincipalsCommandUser , .Cm AuthorizedPrincipalsFile , .Cm Banner , .Cm ChrootDirectory , .Cm DenyGroups , .Cm DenyUsers , .Cm ForceCommand , .Cm GatewayPorts , .Cm GSSAPIAuthentication , .Cm HostbasedAcceptedKeyTypes , .Cm HostbasedAuthentication , .Cm HostbasedUsesNameFromPacketOnly , .Cm IPQoS , .Cm KbdInteractiveAuthentication , .Cm KerberosAuthentication , .Cm MaxAuthTries , .Cm MaxSessions , .Cm PasswordAuthentication , .Cm PermitEmptyPasswords , .Cm PermitOpen , .Cm PermitRootLogin , .Cm PermitTTY , .Cm PermitTunnel , .Cm PermitUserRC , .Cm PubkeyAcceptedKeyTypes , .Cm PubkeyAuthentication , .Cm RekeyLimit , .Cm RevokedKeys , .Cm RhostsRSAAuthentication , .Cm RSAAuthentication , .Cm StreamLocalBindMask , .Cm StreamLocalBindUnlink , .Cm TrustedUserCAKeys , .Cm X11DisplayOffset , .Cm X11Forwarding and .Cm X11UseLocalHost . .It Cm MaxAuthTries Specifies the maximum number of authentication attempts permitted per connection. Once the number of failures reaches half this value, additional failures are logged. The default is 6. .It Cm MaxSessions Specifies the maximum number of open shell, login or subsystem (e.g. sftp) sessions permitted per network connection. Multiple sessions may be established by clients that support connection multiplexing. Setting .Cm MaxSessions to 1 will effectively disable session multiplexing, whereas setting it to 0 will prevent all shell, login and subsystem sessions while still permitting forwarding. The default is 10. .It Cm MaxStartups Specifies the maximum number of concurrent unauthenticated connections to the SSH daemon. Additional connections will be dropped until authentication succeeds or the .Cm LoginGraceTime expires for a connection. The default is 10:30:100. .Pp Alternatively, random early drop can be enabled by specifying the three colon separated values .Dq start:rate:full (e.g. "10:30:60"). .Xr sshd 8 will refuse connection attempts with a probability of .Dq rate/100 (30%) if there are currently .Dq start (10) unauthenticated connections. The probability increases linearly and all connection attempts are refused if the number of unauthenticated connections reaches .Dq full (60). .It Cm PasswordAuthentication Specifies whether password authentication is allowed. See also .Cm UsePAM . The default is .Dq no . .It Cm PermitEmptyPasswords When password authentication is allowed, it specifies whether the server allows login to accounts with empty password strings. The default is .Dq no . .It Cm PermitOpen Specifies the destinations to which TCP port forwarding is permitted. The forwarding specification must be one of the following forms: .Pp .Bl -item -offset indent -compact .It .Cm PermitOpen .Sm off .Ar host : port .Sm on .It .Cm PermitOpen .Sm off .Ar IPv4_addr : port .Sm on .It .Cm PermitOpen .Sm off .Ar \&[ IPv6_addr \&] : port .Sm on .El .Pp Multiple forwards may be specified by separating them with whitespace. An argument of .Dq any can be used to remove all restrictions and permit any forwarding requests. An argument of .Dq none can be used to prohibit all forwarding requests. By default all port forwarding requests are permitted. .It Cm PermitRootLogin Specifies whether root can log in using .Xr ssh 1 . The argument must be .Dq yes , .Dq prohibit-password , .Dq without-password , .Dq forced-commands-only , or .Dq no . The default is .Dq no . Note that if .Cm ChallengeResponseAuthentication is .Dq yes , the root user may be allowed in with its password even if .Cm PermitRootLogin is set to .Dq without-password . .Pp If this option is set to .Dq prohibit-password or .Dq without-password , password and keyboard-interactive authentication are disabled for root. .Pp If this option is set to .Dq forced-commands-only , root login with public key authentication will be allowed, but only if the .Ar command option has been specified (which may be useful for taking remote backups even if root login is normally not allowed). All other authentication methods are disabled for root. .Pp If this option is set to .Dq no , root is not allowed to log in. .It Cm PermitTunnel Specifies whether .Xr tun 4 device forwarding is allowed. The argument must be .Dq yes , .Dq point-to-point (layer 3), .Dq ethernet (layer 2), or .Dq no . Specifying .Dq yes permits both .Dq point-to-point and .Dq ethernet . The default is .Dq no . .Pp Independent of this setting, the permissions of the selected .Xr tun 4 device must allow access to the user. .It Cm PermitTTY Specifies whether .Xr pty 4 allocation is permitted. The default is .Dq yes . .It Cm PermitUserEnvironment Specifies whether .Pa ~/.ssh/environment and .Cm environment= options in .Pa ~/.ssh/authorized_keys are processed by .Xr sshd 8 . The default is .Dq no . Enabling environment processing may enable users to bypass access restrictions in some configurations using mechanisms such as .Ev LD_PRELOAD . .It Cm PermitUserRC Specifies whether any .Pa ~/.ssh/rc file is executed. The default is .Dq yes . .It Cm PidFile Specifies the file that contains the process ID of the SSH daemon, or .Dq none to not write one. The default is .Pa /var/run/sshd.pid . .It Cm Port Specifies the port number that .Xr sshd 8 listens on. The default is 22. Multiple options of this type are permitted. See also .Cm ListenAddress . .It Cm PrintLastLog Specifies whether .Xr sshd 8 should print the date and time of the last user login when a user logs in interactively. The default is .Dq yes . .It Cm PrintMotd Specifies whether .Xr sshd 8 should print .Pa /etc/motd when a user logs in interactively. (On some systems it is also printed by the shell, .Pa /etc/profile , or equivalent.) The default is .Dq yes . .It Cm Protocol Specifies the protocol versions .Xr sshd 8 supports. The possible values are .Sq 1 and .Sq 2 . Multiple versions must be comma-separated. The default is .Sq 2 . Protocol 1 suffers from a number of cryptographic weaknesses and should not be used. It is only offered to support legacy devices. .Pp Note that the order of the protocol list does not indicate preference, because the client selects among multiple protocol versions offered by the server. Specifying .Dq 2,1 is identical to .Dq 1,2 . .It Cm PubkeyAcceptedKeyTypes Specifies the key types that will be accepted for public key authentication as a comma-separated pattern list. Alternately if the specified value begins with a .Sq + character, then the specified key types will be appended to the default set instead of replacing them. The default for this option is: .Bd -literal -offset 3n ecdsa-sha2-nistp256-cert-v01@openssh.com, ecdsa-sha2-nistp384-cert-v01@openssh.com, ecdsa-sha2-nistp521-cert-v01@openssh.com, ssh-ed25519-cert-v01@openssh.com, ssh-rsa-cert-v01@openssh.com, ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521, ssh-ed25519,ssh-rsa .Ed .Pp The .Fl Q option of .Xr ssh 1 may be used to list supported key types. .It Cm PubkeyAuthentication Specifies whether public key authentication is allowed. The default is .Dq yes . .It Cm RekeyLimit Specifies the maximum amount of data that may be transmitted before the session key is renegotiated, optionally followed a maximum amount of time that may pass before the session key is renegotiated. The first argument is specified in bytes and may have a suffix of .Sq K , .Sq M , or .Sq G to indicate Kilobytes, Megabytes, or Gigabytes, respectively. The default is between .Sq 1G and .Sq 4G , depending on the cipher. The optional second value is specified in seconds and may use any of the units documented in the .Sx TIME FORMATS section. The default value for .Cm RekeyLimit is .Dq default none , which means that rekeying is performed after the cipher's default amount of data has been sent or received and no time based rekeying is done. .It Cm RevokedKeys Specifies revoked public keys file, or .Dq none to not use one. Keys listed in this file will be refused for public key authentication. Note that if this file is not readable, then public key authentication will be refused for all users. Keys may be specified as a text file, listing one public key per line, or as an OpenSSH Key Revocation List (KRL) as generated by .Xr ssh-keygen 1 . For more information on KRLs, see the KEY REVOCATION LISTS section in .Xr ssh-keygen 1 . .It Cm RhostsRSAAuthentication Specifies whether rhosts or .Pa /etc/hosts.equiv authentication together with successful RSA host authentication is allowed. The default is .Dq no . This option applies to protocol version 1 only. .It Cm RSAAuthentication Specifies whether pure RSA authentication is allowed. The default is .Dq yes . This option applies to protocol version 1 only. .It Cm ServerKeyBits Defines the number of bits in the ephemeral protocol version 1 server key. The default and minimum value is 1024. .It Cm StreamLocalBindMask Sets the octal file creation mode mask .Pq umask used when creating a Unix-domain socket file for local or remote port forwarding. This option is only used for port forwarding to a Unix-domain socket file. .Pp The default value is 0177, which creates a Unix-domain socket file that is readable and writable only by the owner. Note that not all operating systems honor the file mode on Unix-domain socket files. .It Cm StreamLocalBindUnlink Specifies whether to remove an existing Unix-domain socket file for local or remote port forwarding before creating a new one. If the socket file already exists and .Cm StreamLocalBindUnlink is not enabled, .Nm sshd will be unable to forward the port to the Unix-domain socket file. This option is only used for port forwarding to a Unix-domain socket file. .Pp The argument must be .Dq yes or .Dq no . The default is .Dq no . .It Cm StrictModes Specifies whether .Xr sshd 8 should check file modes and ownership of the user's files and home directory before accepting login. This is normally desirable because novices sometimes accidentally leave their directory or files world-writable. The default is .Dq yes . Note that this does not apply to .Cm ChrootDirectory , whose permissions and ownership are checked unconditionally. .It Cm Subsystem Configures an external subsystem (e.g. file transfer daemon). Arguments should be a subsystem name and a command (with optional arguments) to execute upon subsystem request. .Pp The command .Xr sftp-server 8 implements the .Dq sftp file transfer subsystem. .Pp Alternately the name .Dq internal-sftp implements an in-process .Dq sftp server. This may simplify configurations using .Cm ChrootDirectory to force a different filesystem root on clients. .Pp By default no subsystems are defined. .It Cm SyslogFacility Gives the facility code that is used when logging messages from .Xr sshd 8 . The possible values are: DAEMON, USER, AUTH, LOCAL0, LOCAL1, LOCAL2, LOCAL3, LOCAL4, LOCAL5, LOCAL6, LOCAL7. The default is AUTH. .It Cm TCPKeepAlive Specifies whether the system should send TCP keepalive messages to the other side. If they are sent, death of the connection or crash of one of the machines will be properly noticed. However, this means that connections will die if the route is down temporarily, and some people find it annoying. On the other hand, if TCP keepalives are not sent, sessions may hang indefinitely on the server, leaving .Dq ghost users and consuming server resources. .Pp The default is .Dq yes (to send TCP keepalive messages), and the server will notice if the network goes down or the client host crashes. This avoids infinitely hanging sessions. .Pp To disable TCP keepalive messages, the value should be set to .Dq no . .It Cm TrustedUserCAKeys Specifies a file containing public keys of certificate authorities that are trusted to sign user certificates for authentication, or .Dq none to not use one. Keys are listed one per line; empty lines and comments starting with .Ql # are allowed. If a certificate is presented for authentication and has its signing CA key listed in this file, then it may be used for authentication for any user listed in the certificate's principals list. Note that certificates that lack a list of principals will not be permitted for authentication using .Cm TrustedUserCAKeys . For more details on certificates, see the CERTIFICATES section in .Xr ssh-keygen 1 . +.It Cm UseBlacklist +Specifies whether +.Xr sshd 8 +attempts to send authentication success and failure messages +to the +.Xr blacklistd 8 +daemon. +The default is +.Dq no . .It Cm UseDNS Specifies whether .Xr sshd 8 should look up the remote host name, and to check that the resolved host name for the remote IP address maps back to the very same IP address. .Pp If this option is set to .Dq no , then only addresses and not host names may be used in .Pa ~/.ssh/known_hosts .Cm from and .Nm .Cm Match .Cm Host directives. The default is .Dq yes . .It Cm UseLogin Specifies whether .Xr login 1 is used for interactive login sessions. The default is .Dq no . Note that .Xr login 1 is never used for remote command execution. Note also, that if this is enabled, .Cm X11Forwarding will be disabled because .Xr login 1 does not know how to handle .Xr xauth 1 cookies. If .Cm UsePrivilegeSeparation is specified, it will be disabled after authentication. .It Cm UsePAM Enables the Pluggable Authentication Module interface. If set to .Dq yes this will enable PAM authentication using .Cm ChallengeResponseAuthentication and .Cm PasswordAuthentication in addition to PAM account and session module processing for all authentication types. .Pp Because PAM challenge-response authentication usually serves an equivalent role to password authentication, you should disable either .Cm PasswordAuthentication or .Cm ChallengeResponseAuthentication. .Pp If .Cm UsePAM is enabled, you will not be able to run .Xr sshd 8 as a non-root user. The default is .Dq yes . .It Cm UsePrivilegeSeparation Specifies whether .Xr sshd 8 separates privileges by creating an unprivileged child process to deal with incoming network traffic. After successful authentication, another process will be created that has the privilege of the authenticated user. The goal of privilege separation is to prevent privilege escalation by containing any corruption within the unprivileged processes. The argument must be .Dq yes , .Dq no , or .Dq sandbox . If .Cm UsePrivilegeSeparation is set to .Dq sandbox then the pre-authentication unprivileged process is subject to additional restrictions. The default is .Dq sandbox . .It Cm VersionAddendum Optionally specifies additional text to append to the SSH protocol banner sent by the server upon connection. The default is .Dq FreeBSD-20160310 . The value .Dq none may be used to disable this. .It Cm X11DisplayOffset Specifies the first display number available for .Xr sshd 8 Ns 's X11 forwarding. This prevents sshd from interfering with real X11 servers. The default is 10. .It Cm X11Forwarding Specifies whether X11 forwarding is permitted. The argument must be .Dq yes or .Dq no . The default is .Dq yes . .Pp When X11 forwarding is enabled, there may be additional exposure to the server and to client displays if the .Xr sshd 8 proxy display is configured to listen on the wildcard address (see .Cm X11UseLocalhost below), though this is not the default. Additionally, the authentication spoofing and authentication data verification and substitution occur on the client side. The security risk of using X11 forwarding is that the client's X11 display server may be exposed to attack when the SSH client requests forwarding (see the warnings for .Cm ForwardX11 in .Xr ssh_config 5 ) . A system administrator may have a stance in which they want to protect clients that may expose themselves to attack by unwittingly requesting X11 forwarding, which can warrant a .Dq no setting. .Pp Note that disabling X11 forwarding does not prevent users from forwarding X11 traffic, as users can always install their own forwarders. X11 forwarding is automatically disabled if .Cm UseLogin is enabled. .It Cm X11UseLocalhost Specifies whether .Xr sshd 8 should bind the X11 forwarding server to the loopback address or to the wildcard address. By default, sshd binds the forwarding server to the loopback address and sets the hostname part of the .Ev DISPLAY environment variable to .Dq localhost . This prevents remote hosts from connecting to the proxy display. However, some older X11 clients may not function with this configuration. .Cm X11UseLocalhost may be set to .Dq no to specify that the forwarding server should be bound to the wildcard address. The argument must be .Dq yes or .Dq no . The default is .Dq yes . .It Cm XAuthLocation Specifies the full pathname of the .Xr xauth 1 program, or .Dq none to not use one. The default is .Pa /usr/local/bin/xauth . .El .Sh TIME FORMATS .Xr sshd 8 command-line arguments and configuration file options that specify time may be expressed using a sequence of the form: .Sm off .Ar time Op Ar qualifier , .Sm on where .Ar time is a positive integer value and .Ar qualifier is one of the following: .Pp .Bl -tag -width Ds -compact -offset indent .It Aq Cm none seconds .It Cm s | Cm S seconds .It Cm m | Cm M minutes .It Cm h | Cm H hours .It Cm d | Cm D days .It Cm w | Cm W weeks .El .Pp Each member of the sequence is added together to calculate the total time value. .Pp Time format examples: .Pp .Bl -tag -width Ds -compact -offset indent .It 600 600 seconds (10 minutes) .It 10m 10 minutes .It 1h30m 1 hour 30 minutes (90 minutes) .El .Sh FILES .Bl -tag -width Ds .It Pa /etc/ssh/sshd_config Contains configuration data for .Xr sshd 8 . This file should be writable by root only, but it is recommended (though not necessary) that it be world-readable. .El .Sh SEE ALSO .Xr sshd 8 .Sh AUTHORS OpenSSH is a derivative of the original and free ssh 1.2.12 release by Tatu Ylonen. Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos, Theo de Raadt and Dug Song removed many bugs, re-added newer features and created OpenSSH. Markus Friedl contributed the support for SSH protocol versions 1.5 and 2.0. Niels Provos and Markus Friedl contributed support for privilege separation. diff --git a/secure/usr.sbin/sshd/Makefile b/secure/usr.sbin/sshd/Makefile index f9589a37ae37..af760992b725 100644 --- a/secure/usr.sbin/sshd/Makefile +++ b/secure/usr.sbin/sshd/Makefile @@ -1,57 +1,64 @@ # $FreeBSD$ .include PROG= sshd SRCS= sshd.c auth-rhosts.c auth-passwd.c auth-rsa.c auth-rh-rsa.c \ audit.c audit-bsm.c audit-linux.c platform.c \ sshpty.c sshlogin.c servconf.c serverloop.c \ auth.c auth1.c auth2.c auth-options.c session.c \ auth-chall.c auth2-chall.c groupaccess.c \ auth-skey.c auth-bsdauth.c auth2-hostbased.c auth2-kbdint.c \ auth2-none.c auth2-passwd.c auth2-pubkey.c \ monitor_mm.c monitor.c monitor_wrap.c auth-krb5.c \ auth2-gss.c gss-serv.c gss-serv-krb5.c \ loginrec.c auth-pam.c auth-shadow.c auth-sia.c md5crypt.c \ sftp-server.c sftp-common.c \ sandbox-null.c sandbox-rlimit.c sandbox-systrace.c sandbox-darwin.c \ sandbox-seccomp-filter.c sandbox-capsicum.c sandbox-pledge.c \ sandbox-solaris.c PACKAGE= ssh # gss-genr.c really belongs in libssh; see src/secure/lib/libssh/Makefile SRCS+= gss-genr.c MAN= sshd.8 sshd_config.5 CFLAGS+=-I${SSHDIR} -include ssh_namespace.h SRCS+= ssh_namespace.h # pam should always happen before ssh here for static linking LIBADD= pam ssh util wrap .if ${MK_LDNS} != "no" CFLAGS+= -DHAVE_LDNS=1 #DPADD+= ${LIBLDNS} #LDADD+= -lldns .endif .if ${MK_AUDIT} != "no" CFLAGS+= -DUSE_BSM_AUDIT -DHAVE_GETAUDIT_ADDR LIBADD+= bsm .endif +.if ${MK_BLACKLIST_SUPPORT} != "no" +CFLAGS+= -DUSE_BLACKLIST -I${SRCTOP}/contrib/blacklist/include +SRCS+= blacklist.c +LIBADD+= blacklist +LDFLAGS+=-L${LIBBLACKLISTDIR} +.endif + .if ${MK_KERBEROS_SUPPORT} != "no" CFLAGS+= -include krb5_config.h SRCS+= krb5_config.h LIBADD+= gssapi_krb5 gssapi krb5 .endif LIBADD+= crypto .if defined(LOCALBASE) CFLAGS+= -DXAUTH_PATH=\"${LOCALBASE}/bin/xauth\" .endif .include .PATH: ${SSHDIR} diff --git a/secure/usr.sbin/sshd/Makefile.depend b/secure/usr.sbin/sshd/Makefile.depend index d24b0bef5d55..220aae36c11c 100644 --- a/secure/usr.sbin/sshd/Makefile.depend +++ b/secure/usr.sbin/sshd/Makefile.depend @@ -1,40 +1,41 @@ # $FreeBSD$ # Autogenerated - do NOT edit! DIRDEPS = \ gnu/lib/csu \ gnu/lib/libgcc \ include \ include/arpa \ include/gssapi \ include/xlocale \ kerberos5/lib/libasn1 \ kerberos5/lib/libgssapi_krb5 \ kerberos5/lib/libheimbase \ kerberos5/lib/libheimipcc \ kerberos5/lib/libhx509 \ kerberos5/lib/libkrb5 \ kerberos5/lib/libroken \ kerberos5/lib/libwind \ lib/${CSU_DIR} \ + lib/libblacklist \ lib/libbsm \ lib/libc \ lib/libcom_err \ lib/libcompiler_rt \ lib/libcrypt \ lib/libgssapi \ lib/libldns \ lib/libpam/libpam \ lib/libthr \ lib/libutil \ lib/libwrap \ lib/libz \ secure/lib/libcrypto \ secure/lib/libssh \ .include .if ${DEP_RELDIR} == ${_DEP_RELDIR} # local dependencies - needed for -jN in clean tree .endif