Index: head/crypto/openssh/monitor.c =================================================================== --- head/crypto/openssh/monitor.c (revision 287142) +++ head/crypto/openssh/monitor.c (revision 287143) @@ -1,2139 +1,2139 @@ /* $OpenBSD: monitor.c,v 1.131 2014/02/02 03:44:31 djm Exp $ */ /* * Copyright 2002 Niels Provos * Copyright 2002 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" #include #include #include #include "openbsd-compat/sys-tree.h" #include #include #include #ifdef HAVE_PATHS_H #include #endif #include #include #include #include #include #include #ifdef HAVE_POLL_H #include #else # ifdef HAVE_SYS_POLL_H # include # endif #endif #ifdef SKEY #include #endif #include #include "openbsd-compat/sys-queue.h" #include "atomicio.h" #include "xmalloc.h" #include "ssh.h" #include "key.h" #include "buffer.h" #include "hostfile.h" #include "auth.h" #include "cipher.h" #include "kex.h" #include "dh.h" #ifdef TARGET_OS_MAC /* XXX Broken krb5 headers on Mac */ #undef TARGET_OS_MAC #include "zlib.h" #define TARGET_OS_MAC 1 #else #include "zlib.h" #endif #include "packet.h" #include "auth-options.h" #include "sshpty.h" #include "channels.h" #include "session.h" #include "sshlogin.h" #include "canohost.h" #include "log.h" #include "servconf.h" #include "monitor.h" #include "monitor_mm.h" #ifdef GSSAPI #include "ssh-gss.h" #endif #include "monitor_wrap.h" #include "monitor_fdpass.h" #include "misc.h" #include "compat.h" #include "ssh2.h" #include "roaming.h" #include "authfd.h" #ifdef GSSAPI static Gssctxt *gsscontext = NULL; #endif /* Imports */ extern ServerOptions options; extern u_int utmp_len; extern Newkeys *current_keys[]; extern z_stream incoming_stream; extern z_stream outgoing_stream; extern u_char session_id[]; extern Buffer auth_debug; extern int auth_debug_init; extern Buffer loginmsg; /* State exported from the child */ struct { z_stream incoming; z_stream outgoing; u_char *keyin; u_int keyinlen; u_char *keyout; u_int keyoutlen; u_char *ivin; u_int ivinlen; u_char *ivout; u_int ivoutlen; u_char *ssh1key; u_int ssh1keylen; int ssh1cipher; int ssh1protoflags; u_char *input; u_int ilen; u_char *output; u_int olen; u_int64_t sent_bytes; u_int64_t recv_bytes; } child_state; /* Functions on the monitor that answer unprivileged requests */ int mm_answer_moduli(int, Buffer *); int mm_answer_sign(int, Buffer *); int mm_answer_pwnamallow(int, Buffer *); int mm_answer_auth2_read_banner(int, Buffer *); int mm_answer_authserv(int, Buffer *); int mm_answer_authpassword(int, Buffer *); int mm_answer_bsdauthquery(int, Buffer *); int mm_answer_bsdauthrespond(int, Buffer *); int mm_answer_skeyquery(int, Buffer *); int mm_answer_skeyrespond(int, Buffer *); int mm_answer_keyallowed(int, Buffer *); int mm_answer_keyverify(int, Buffer *); int mm_answer_pty(int, Buffer *); int mm_answer_pty_cleanup(int, Buffer *); int mm_answer_term(int, Buffer *); int mm_answer_rsa_keyallowed(int, Buffer *); int mm_answer_rsa_challenge(int, Buffer *); int mm_answer_rsa_response(int, Buffer *); int mm_answer_sesskey(int, Buffer *); int mm_answer_sessid(int, Buffer *); #ifdef USE_PAM int mm_answer_pam_start(int, Buffer *); int mm_answer_pam_account(int, Buffer *); int mm_answer_pam_init_ctx(int, Buffer *); int mm_answer_pam_query(int, Buffer *); int mm_answer_pam_respond(int, Buffer *); int mm_answer_pam_free_ctx(int, Buffer *); #endif #ifdef GSSAPI int mm_answer_gss_setup_ctx(int, Buffer *); int mm_answer_gss_accept_ctx(int, Buffer *); int mm_answer_gss_userok(int, Buffer *); int mm_answer_gss_checkmic(int, Buffer *); #endif #ifdef SSH_AUDIT_EVENTS int mm_answer_audit_event(int, Buffer *); int mm_answer_audit_command(int, Buffer *); #endif static int monitor_read_log(struct monitor *); static Authctxt *authctxt; static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ /* local state for key verify */ static u_char *key_blob = NULL; static u_int key_bloblen = 0; static int key_blobtype = MM_NOKEY; static char *hostbased_cuser = NULL; static char *hostbased_chost = NULL; static char *auth_method = "unknown"; static char *auth_submethod = NULL; static u_int session_id2_len = 0; static u_char *session_id2 = NULL; static pid_t monitor_child_pid; struct mon_table { enum monitor_reqtype type; int flags; int (*f)(int, Buffer *); }; #define MON_ISAUTH 0x0004 /* Required for Authentication */ #define MON_AUTHDECIDE 0x0008 /* Decides Authentication */ #define MON_ONCE 0x0010 /* Disable after calling */ #define MON_ALOG 0x0020 /* Log auth attempt without authenticating */ #define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE) #define MON_PERMIT 0x1000 /* Request is permitted */ struct mon_table mon_dispatch_proto20[] = { {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli}, {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign}, {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv}, {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, #ifdef USE_PAM {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, #endif #ifdef SSH_AUDIT_EVENTS {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, #endif #ifdef BSD_AUTH {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, #endif #ifdef SKEY {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, #endif {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed}, {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify}, #ifdef GSSAPI {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx}, {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok}, {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic}, #endif {0, 0, NULL} }; struct mon_table mon_dispatch_postauth20[] = { {MONITOR_REQ_MODULI, 0, mm_answer_moduli}, {MONITOR_REQ_SIGN, 0, mm_answer_sign}, {MONITOR_REQ_PTY, 0, mm_answer_pty}, {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, {MONITOR_REQ_TERM, 0, mm_answer_term}, #ifdef SSH_AUDIT_EVENTS {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command}, #endif {0, 0, NULL} }; struct mon_table mon_dispatch_proto15[] = { {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow}, {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey}, {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid}, {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_rsa_keyallowed}, {MONITOR_REQ_KEYALLOWED, MON_ISAUTH|MON_ALOG, mm_answer_keyallowed}, {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge}, {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response}, #ifdef BSD_AUTH {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond}, #endif #ifdef SKEY {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery}, {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond}, #endif #ifdef USE_PAM {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start}, {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account}, {MONITOR_REQ_PAM_INIT_CTX, MON_ISAUTH, mm_answer_pam_init_ctx}, {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, #endif #ifdef SSH_AUDIT_EVENTS {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, #endif {0, 0, NULL} }; struct mon_table mon_dispatch_postauth15[] = { {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, {MONITOR_REQ_TERM, 0, mm_answer_term}, #ifdef SSH_AUDIT_EVENTS {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command}, #endif {0, 0, NULL} }; struct mon_table *mon_dispatch; /* Specifies if a certain message is allowed at the moment */ static void monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit) { while (ent->f != NULL) { if (ent->type == type) { ent->flags &= ~MON_PERMIT; ent->flags |= permit ? MON_PERMIT : 0; return; } ent++; } } static void monitor_permit_authentications(int permit) { struct mon_table *ent = mon_dispatch; while (ent->f != NULL) { if (ent->flags & MON_AUTH) { ent->flags &= ~MON_PERMIT; ent->flags |= permit ? MON_PERMIT : 0; } ent++; } } void monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor) { struct mon_table *ent; int authenticated = 0, partial = 0; debug3("preauth child monitor started"); close(pmonitor->m_recvfd); close(pmonitor->m_log_sendfd); pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1; authctxt = _authctxt; memset(authctxt, 0, sizeof(*authctxt)); authctxt->loginmsg = &loginmsg; if (compat20) { mon_dispatch = mon_dispatch_proto20; /* Permit requests for moduli and signatures */ monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); } else { mon_dispatch = mon_dispatch_proto15; monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1); } /* The first few requests do not require asynchronous access */ while (!authenticated) { partial = 0; auth_method = "unknown"; auth_submethod = NULL; authenticated = (monitor_read(pmonitor, mon_dispatch, &ent) == 1); /* Special handling for multiple required authentications */ if (options.num_auth_methods != 0) { if (!compat20) fatal("AuthenticationMethods is not supported" "with SSH protocol 1"); if (authenticated && !auth2_update_methods_lists(authctxt, auth_method, auth_submethod)) { debug3("%s: method %s: partial", __func__, auth_method); authenticated = 0; partial = 1; } } if (authenticated) { if (!(ent->flags & MON_AUTHDECIDE)) fatal("%s: unexpected authentication from %d", __func__, ent->type); if (authctxt->pw->pw_uid == 0 && !auth_root_allowed(auth_method)) authenticated = 0; #ifdef USE_PAM /* PAM needs to perform account checks after auth */ if (options.use_pam && authenticated) { Buffer m; buffer_init(&m); mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_PAM_ACCOUNT, &m); authenticated = mm_answer_pam_account(pmonitor->m_sendfd, &m); buffer_free(&m); } #endif } if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) { auth_log(authctxt, authenticated, partial, auth_method, auth_submethod); if (!authenticated) authctxt->failures++; } } if (!authctxt->valid) fatal("%s: authenticated invalid user", __func__); if (strcmp(auth_method, "unknown") == 0) fatal("%s: authentication method name unknown", __func__); debug("%s: %s has been authenticated by privileged process", __func__, authctxt->user); mm_get_keystate(pmonitor); /* Drain any buffered messages from the child */ while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0) ; close(pmonitor->m_sendfd); close(pmonitor->m_log_recvfd); pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1; } static void monitor_set_child_handler(pid_t pid) { monitor_child_pid = pid; } static void monitor_child_handler(int sig) { kill(monitor_child_pid, sig); } void monitor_child_postauth(struct monitor *pmonitor) { close(pmonitor->m_recvfd); pmonitor->m_recvfd = -1; monitor_set_child_handler(pmonitor->m_pid); signal(SIGHUP, &monitor_child_handler); signal(SIGTERM, &monitor_child_handler); signal(SIGINT, &monitor_child_handler); if (compat20) { mon_dispatch = mon_dispatch_postauth20; /* Permit requests for moduli and signatures */ monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); } else { mon_dispatch = mon_dispatch_postauth15; monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); } if (!no_pty_flag) { monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1); monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1); } for (;;) monitor_read(pmonitor, mon_dispatch, NULL); } void monitor_sync(struct monitor *pmonitor) { if (options.compression) { /* The member allocation is not visible, so sync it */ mm_share_sync(&pmonitor->m_zlib, &pmonitor->m_zback); } } static int monitor_read_log(struct monitor *pmonitor) { Buffer logmsg; u_int len, level; char *msg; buffer_init(&logmsg); /* Read length */ buffer_append_space(&logmsg, 4); if (atomicio(read, pmonitor->m_log_recvfd, buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) { if (errno == EPIPE) { buffer_free(&logmsg); debug("%s: child log fd closed", __func__); close(pmonitor->m_log_recvfd); pmonitor->m_log_recvfd = -1; return -1; } fatal("%s: log fd read: %s", __func__, strerror(errno)); } len = buffer_get_int(&logmsg); if (len <= 4 || len > 8192) fatal("%s: invalid log message length %u", __func__, len); /* Read severity, message */ buffer_clear(&logmsg); buffer_append_space(&logmsg, len); if (atomicio(read, pmonitor->m_log_recvfd, buffer_ptr(&logmsg), buffer_len(&logmsg)) != buffer_len(&logmsg)) fatal("%s: log fd read: %s", __func__, strerror(errno)); /* Log it */ level = buffer_get_int(&logmsg); msg = buffer_get_string(&logmsg, NULL); if (log_level_name(level) == NULL) fatal("%s: invalid log level %u (corrupted message?)", __func__, level); do_log2(level, "%s [preauth]", msg); buffer_free(&logmsg); free(msg); return 0; } int monitor_read(struct monitor *pmonitor, struct mon_table *ent, struct mon_table **pent) { Buffer m; int ret; u_char type; struct pollfd pfd[2]; for (;;) { memset(&pfd, 0, sizeof(pfd)); pfd[0].fd = pmonitor->m_sendfd; pfd[0].events = POLLIN; pfd[1].fd = pmonitor->m_log_recvfd; pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN; if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) { if (errno == EINTR || errno == EAGAIN) continue; fatal("%s: poll: %s", __func__, strerror(errno)); } if (pfd[1].revents) { /* * Drain all log messages before processing next * monitor request. */ monitor_read_log(pmonitor); continue; } if (pfd[0].revents) break; /* Continues below */ } buffer_init(&m); mm_request_receive(pmonitor->m_sendfd, &m); type = buffer_get_char(&m); debug3("%s: checking request %d", __func__, type); while (ent->f != NULL) { if (ent->type == type) break; ent++; } if (ent->f != NULL) { if (!(ent->flags & MON_PERMIT)) fatal("%s: unpermitted request %d", __func__, type); ret = (*ent->f)(pmonitor->m_sendfd, &m); buffer_free(&m); /* The child may use this request only once, disable it */ if (ent->flags & MON_ONCE) { debug2("%s: %d used once, disabling now", __func__, type); ent->flags &= ~MON_PERMIT; } if (pent != NULL) *pent = ent; return ret; } fatal("%s: unsupported request: %d", __func__, type); /* NOTREACHED */ return (-1); } /* allowed key state */ static int monitor_allowed_key(u_char *blob, u_int bloblen) { /* make sure key is allowed */ if (key_blob == NULL || key_bloblen != bloblen || timingsafe_bcmp(key_blob, blob, key_bloblen)) return (0); return (1); } static void monitor_reset_key_state(void) { /* reset state */ free(key_blob); free(hostbased_cuser); free(hostbased_chost); key_blob = NULL; key_bloblen = 0; key_blobtype = MM_NOKEY; hostbased_cuser = NULL; hostbased_chost = NULL; } int mm_answer_moduli(int sock, Buffer *m) { DH *dh; int min, want, max; min = buffer_get_int(m); want = buffer_get_int(m); max = buffer_get_int(m); debug3("%s: got parameters: %d %d %d", __func__, min, want, max); /* We need to check here, too, in case the child got corrupted */ if (max < min || want < min || max < want) fatal("%s: bad parameters: %d %d %d", __func__, min, want, max); buffer_clear(m); dh = choose_dh(min, want, max); if (dh == NULL) { buffer_put_char(m, 0); return (0); } else { /* Send first bignum */ buffer_put_char(m, 1); buffer_put_bignum2(m, dh->p); buffer_put_bignum2(m, dh->g); DH_free(dh); } mm_request_send(sock, MONITOR_ANS_MODULI, m); return (0); } extern AuthenticationConnection *auth_conn; int mm_answer_sign(int sock, Buffer *m) { Key *key; u_char *p; u_char *signature; u_int siglen, datlen; int keyid; debug3("%s", __func__); keyid = buffer_get_int(m); p = buffer_get_string(m, &datlen); /* * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes), * SHA384 (48 bytes) and SHA512 (64 bytes). */ if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) fatal("%s: data length incorrect: %u", __func__, datlen); /* save session id, it will be passed on the first call */ if (session_id2_len == 0) { session_id2_len = datlen; session_id2 = xmalloc(session_id2_len); memcpy(session_id2, p, session_id2_len); } if ((key = get_hostkey_by_index(keyid)) != NULL) { if (key_sign(key, &signature, &siglen, p, datlen) < 0) fatal("%s: key_sign failed", __func__); } else if ((key = get_hostkey_public_by_index(keyid)) != NULL && auth_conn != NULL) { if (ssh_agent_sign(auth_conn, key, &signature, &siglen, p, datlen) < 0) fatal("%s: ssh_agent_sign failed", __func__); } else fatal("%s: no hostkey from index %d", __func__, keyid); debug3("%s: signature %p(%u)", __func__, signature, siglen); buffer_clear(m); buffer_put_string(m, signature, siglen); free(p); free(signature); mm_request_send(sock, MONITOR_ANS_SIGN, m); /* Turn on permissions for getpwnam */ monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); return (0); } /* Retrieves the password entry and also checks if the user is permitted */ int mm_answer_pwnamallow(int sock, Buffer *m) { char *username; struct passwd *pwent; int allowed = 0; u_int i; debug3("%s", __func__); if (authctxt->attempt++ != 0) fatal("%s: multiple attempts for getpwnam", __func__); username = buffer_get_string(m, NULL); pwent = getpwnamallow(username); authctxt->user = xstrdup(username); setproctitle("%s [priv]", pwent ? username : "unknown"); free(username); buffer_clear(m); if (pwent == NULL) { buffer_put_char(m, 0); authctxt->pw = fakepw(); goto out; } allowed = 1; authctxt->pw = pwent; authctxt->valid = 1; buffer_put_char(m, 1); buffer_put_string(m, pwent, sizeof(struct passwd)); buffer_put_cstring(m, pwent->pw_name); buffer_put_cstring(m, "*"); #ifdef HAVE_STRUCT_PASSWD_PW_GECOS buffer_put_cstring(m, pwent->pw_gecos); #endif #ifdef HAVE_STRUCT_PASSWD_PW_CLASS buffer_put_cstring(m, pwent->pw_class); #endif buffer_put_cstring(m, pwent->pw_dir); buffer_put_cstring(m, pwent->pw_shell); out: buffer_put_string(m, &options, sizeof(options)); #define M_CP_STROPT(x) do { \ if (options.x != NULL) \ buffer_put_cstring(m, options.x); \ } while (0) #define M_CP_STRARRAYOPT(x, nx) do { \ for (i = 0; i < options.nx; i++) \ buffer_put_cstring(m, options.x[i]); \ } while (0) /* See comment in servconf.h */ COPY_MATCH_STRING_OPTS(); #undef M_CP_STROPT #undef M_CP_STRARRAYOPT /* Create valid auth method lists */ if (compat20 && auth2_setup_methods_lists(authctxt) != 0) { /* * The monitor will continue long enough to let the child * run to it's packet_disconnect(), but it must not allow any * authentication to succeed. */ debug("%s: no valid authentication method lists", __func__); } debug3("%s: sending MONITOR_ANS_PWNAM: %d", __func__, allowed); mm_request_send(sock, MONITOR_ANS_PWNAM, m); /* For SSHv1 allow authentication now */ if (!compat20) monitor_permit_authentications(1); else { /* Allow service/style information on the auth context */ monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); } #ifdef USE_PAM if (options.use_pam) monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1); #endif return (0); } int mm_answer_auth2_read_banner(int sock, Buffer *m) { char *banner; buffer_clear(m); banner = auth2_read_banner(); buffer_put_cstring(m, banner != NULL ? banner : ""); mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m); free(banner); return (0); } int mm_answer_authserv(int sock, Buffer *m) { monitor_permit_authentications(1); authctxt->service = buffer_get_string(m, NULL); authctxt->style = buffer_get_string(m, NULL); debug3("%s: service=%s, style=%s", __func__, authctxt->service, authctxt->style); if (strlen(authctxt->style) == 0) { free(authctxt->style); authctxt->style = NULL; } return (0); } int mm_answer_authpassword(int sock, Buffer *m) { static int call_count; char *passwd; int authenticated; u_int plen; passwd = buffer_get_string(m, &plen); /* Only authenticate if the context is valid */ authenticated = options.password_authentication && auth_password(authctxt, passwd); explicit_bzero(passwd, strlen(passwd)); free(passwd); buffer_clear(m); buffer_put_int(m, authenticated); debug3("%s: sending result %d", __func__, authenticated); mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m); call_count++; if (plen == 0 && call_count == 1) auth_method = "none"; else auth_method = "password"; /* Causes monitor loop to terminate if authenticated */ return (authenticated); } #ifdef BSD_AUTH int mm_answer_bsdauthquery(int sock, Buffer *m) { char *name, *infotxt; u_int numprompts; u_int *echo_on; char **prompts; u_int success; success = bsdauth_query(authctxt, &name, &infotxt, &numprompts, &prompts, &echo_on) < 0 ? 0 : 1; buffer_clear(m); buffer_put_int(m, success); if (success) buffer_put_cstring(m, prompts[0]); debug3("%s: sending challenge success: %u", __func__, success); mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m); if (success) { free(name); free(infotxt); free(prompts); free(echo_on); } return (0); } int mm_answer_bsdauthrespond(int sock, Buffer *m) { char *response; int authok; if (authctxt->as == 0) fatal("%s: no bsd auth session", __func__); response = buffer_get_string(m, NULL); authok = options.challenge_response_authentication && auth_userresponse(authctxt->as, response, 0); authctxt->as = NULL; debug3("%s: <%s> = <%d>", __func__, response, authok); free(response); buffer_clear(m); buffer_put_int(m, authok); debug3("%s: sending authenticated: %d", __func__, authok); mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m); if (compat20) { auth_method = "keyboard-interactive"; auth_submethod = "bsdauth"; } else auth_method = "bsdauth"; return (authok != 0); } #endif #ifdef SKEY int mm_answer_skeyquery(int sock, Buffer *m) { struct skey skey; char challenge[1024]; u_int success; success = _compat_skeychallenge(&skey, authctxt->user, challenge, sizeof(challenge)) < 0 ? 0 : 1; buffer_clear(m); buffer_put_int(m, success); if (success) buffer_put_cstring(m, challenge); debug3("%s: sending challenge success: %u", __func__, success); mm_request_send(sock, MONITOR_ANS_SKEYQUERY, m); return (0); } int mm_answer_skeyrespond(int sock, Buffer *m) { char *response; int authok; response = buffer_get_string(m, NULL); authok = (options.challenge_response_authentication && authctxt->valid && skey_haskey(authctxt->pw->pw_name) == 0 && skey_passcheck(authctxt->pw->pw_name, response) != -1); free(response); buffer_clear(m); buffer_put_int(m, authok); debug3("%s: sending authenticated: %d", __func__, authok); mm_request_send(sock, MONITOR_ANS_SKEYRESPOND, m); auth_method = "skey"; return (authok != 0); } #endif #ifdef USE_PAM int mm_answer_pam_start(int sock, Buffer *m) { if (!options.use_pam) fatal("UsePAM not set, but ended up in %s anyway", __func__); start_pam(authctxt); monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1); return (0); } int mm_answer_pam_account(int sock, Buffer *m) { u_int ret; if (!options.use_pam) fatal("UsePAM not set, but ended up in %s anyway", __func__); ret = do_pam_account(); buffer_put_int(m, ret); buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m); return (ret); } static void *sshpam_ctxt, *sshpam_authok; extern KbdintDevice sshpam_device; int mm_answer_pam_init_ctx(int sock, Buffer *m) { - debug3("%s", __func__); - authctxt->user = buffer_get_string(m, NULL); sshpam_ctxt = (sshpam_device.init_ctx)(authctxt); sshpam_authok = NULL; buffer_clear(m); if (sshpam_ctxt != NULL) { monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1); buffer_put_int(m, 1); } else { buffer_put_int(m, 0); } mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m); return (0); } int mm_answer_pam_query(int sock, Buffer *m) { char *name = NULL, *info = NULL, **prompts = NULL; u_int i, num = 0, *echo_on = 0; int ret; debug3("%s", __func__); sshpam_authok = NULL; ret = (sshpam_device.query)(sshpam_ctxt, &name, &info, &num, &prompts, &echo_on); if (ret == 0 && num == 0) sshpam_authok = sshpam_ctxt; if (num > 1 || name == NULL || info == NULL) ret = -1; buffer_clear(m); buffer_put_int(m, ret); buffer_put_cstring(m, name); free(name); buffer_put_cstring(m, info); free(info); buffer_put_int(m, num); for (i = 0; i < num; ++i) { buffer_put_cstring(m, prompts[i]); free(prompts[i]); buffer_put_int(m, echo_on[i]); } free(prompts); free(echo_on); auth_method = "keyboard-interactive"; auth_submethod = "pam"; mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m); return (0); } int mm_answer_pam_respond(int sock, Buffer *m) { char **resp; u_int i, num; int ret; debug3("%s", __func__); sshpam_authok = NULL; num = buffer_get_int(m); if (num > 0) { resp = xcalloc(num, sizeof(char *)); for (i = 0; i < num; ++i) resp[i] = buffer_get_string(m, NULL); ret = (sshpam_device.respond)(sshpam_ctxt, num, resp); for (i = 0; i < num; ++i) free(resp[i]); free(resp); } else { ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL); } buffer_clear(m); buffer_put_int(m, ret); mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m); auth_method = "keyboard-interactive"; auth_submethod = "pam"; if (ret == 0) sshpam_authok = sshpam_ctxt; return (0); } int mm_answer_pam_free_ctx(int sock, Buffer *m) { + int r = sshpam_authok != NULL && sshpam_authok == sshpam_ctxt; debug3("%s", __func__); (sshpam_device.free_ctx)(sshpam_ctxt); + sshpam_ctxt = sshpam_authok = NULL; buffer_clear(m); mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m); auth_method = "keyboard-interactive"; auth_submethod = "pam"; - return (sshpam_authok == sshpam_ctxt); + return r; } #endif int mm_answer_keyallowed(int sock, Buffer *m) { Key *key; char *cuser, *chost; u_char *blob; u_int bloblen; enum mm_keytype type = 0; int allowed = 0; debug3("%s entering", __func__); type = buffer_get_int(m); cuser = buffer_get_string(m, NULL); chost = buffer_get_string(m, NULL); blob = buffer_get_string(m, &bloblen); key = key_from_blob(blob, bloblen); if ((compat20 && type == MM_RSAHOSTKEY) || (!compat20 && type != MM_RSAHOSTKEY)) fatal("%s: key type and protocol mismatch", __func__); debug3("%s: key_from_blob: %p", __func__, key); if (key != NULL && authctxt->valid) { switch (type) { case MM_USERKEY: allowed = options.pubkey_authentication && user_key_allowed(authctxt->pw, key); pubkey_auth_info(authctxt, key, NULL); auth_method = "publickey"; if (options.pubkey_authentication && allowed != 1) auth_clear_options(); break; case MM_HOSTKEY: allowed = options.hostbased_authentication && hostbased_key_allowed(authctxt->pw, cuser, chost, key); pubkey_auth_info(authctxt, key, "client user \"%.100s\", client host \"%.100s\"", cuser, chost); auth_method = "hostbased"; break; case MM_RSAHOSTKEY: key->type = KEY_RSA1; /* XXX */ allowed = options.rhosts_rsa_authentication && auth_rhosts_rsa_key_allowed(authctxt->pw, cuser, chost, key); if (options.rhosts_rsa_authentication && allowed != 1) auth_clear_options(); auth_method = "rsa"; break; default: fatal("%s: unknown key type %d", __func__, type); break; } } if (key != NULL) key_free(key); /* clear temporarily storage (used by verify) */ monitor_reset_key_state(); if (allowed) { /* Save temporarily for comparison in verify */ key_blob = blob; key_bloblen = bloblen; key_blobtype = type; hostbased_cuser = cuser; hostbased_chost = chost; } else { /* Log failed attempt */ auth_log(authctxt, 0, 0, auth_method, NULL); free(blob); free(cuser); free(chost); } debug3("%s: key %p is %s", __func__, key, allowed ? "allowed" : "not allowed"); buffer_clear(m); buffer_put_int(m, allowed); buffer_put_int(m, forced_command != NULL); mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m); if (type == MM_RSAHOSTKEY) monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); return (0); } static int monitor_valid_userblob(u_char *data, u_int datalen) { Buffer b; char *p, *userstyle; u_int len; int fail = 0; buffer_init(&b); buffer_append(&b, data, datalen); if (datafellows & SSH_OLD_SESSIONID) { p = buffer_ptr(&b); len = buffer_len(&b); if ((session_id2 == NULL) || (len < session_id2_len) || (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) fail++; buffer_consume(&b, session_id2_len); } else { p = buffer_get_string(&b, &len); if ((session_id2 == NULL) || (len != session_id2_len) || (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) fail++; free(p); } if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) fail++; p = buffer_get_cstring(&b, NULL); xasprintf(&userstyle, "%s%s%s", authctxt->user, authctxt->style ? ":" : "", authctxt->style ? authctxt->style : ""); if (strcmp(userstyle, p) != 0) { logit("wrong user name passed to monitor: expected %s != %.100s", userstyle, p); fail++; } free(userstyle); free(p); buffer_skip_string(&b); if (datafellows & SSH_BUG_PKAUTH) { if (!buffer_get_char(&b)) fail++; } else { p = buffer_get_cstring(&b, NULL); if (strcmp("publickey", p) != 0) fail++; free(p); if (!buffer_get_char(&b)) fail++; buffer_skip_string(&b); } buffer_skip_string(&b); if (buffer_len(&b) != 0) fail++; buffer_free(&b); return (fail == 0); } static int monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser, char *chost) { Buffer b; char *p, *userstyle; u_int len; int fail = 0; buffer_init(&b); buffer_append(&b, data, datalen); p = buffer_get_string(&b, &len); if ((session_id2 == NULL) || (len != session_id2_len) || (timingsafe_bcmp(p, session_id2, session_id2_len) != 0)) fail++; free(p); if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST) fail++; p = buffer_get_cstring(&b, NULL); xasprintf(&userstyle, "%s%s%s", authctxt->user, authctxt->style ? ":" : "", authctxt->style ? authctxt->style : ""); if (strcmp(userstyle, p) != 0) { logit("wrong user name passed to monitor: expected %s != %.100s", userstyle, p); fail++; } free(userstyle); free(p); buffer_skip_string(&b); /* service */ p = buffer_get_cstring(&b, NULL); if (strcmp(p, "hostbased") != 0) fail++; free(p); buffer_skip_string(&b); /* pkalg */ buffer_skip_string(&b); /* pkblob */ /* verify client host, strip trailing dot if necessary */ p = buffer_get_string(&b, NULL); if (((len = strlen(p)) > 0) && p[len - 1] == '.') p[len - 1] = '\0'; if (strcmp(p, chost) != 0) fail++; free(p); /* verify client user */ p = buffer_get_string(&b, NULL); if (strcmp(p, cuser) != 0) fail++; free(p); if (buffer_len(&b) != 0) fail++; buffer_free(&b); return (fail == 0); } int mm_answer_keyverify(int sock, Buffer *m) { Key *key; u_char *signature, *data, *blob; u_int signaturelen, datalen, bloblen; int verified = 0; int valid_data = 0; blob = buffer_get_string(m, &bloblen); signature = buffer_get_string(m, &signaturelen); data = buffer_get_string(m, &datalen); if (hostbased_cuser == NULL || hostbased_chost == NULL || !monitor_allowed_key(blob, bloblen)) fatal("%s: bad key, not previously allowed", __func__); key = key_from_blob(blob, bloblen); if (key == NULL) fatal("%s: bad public key blob", __func__); switch (key_blobtype) { case MM_USERKEY: valid_data = monitor_valid_userblob(data, datalen); break; case MM_HOSTKEY: valid_data = monitor_valid_hostbasedblob(data, datalen, hostbased_cuser, hostbased_chost); break; default: valid_data = 0; break; } if (!valid_data) fatal("%s: bad signature data blob", __func__); verified = key_verify(key, signature, signaturelen, data, datalen); debug3("%s: key %p signature %s", __func__, key, (verified == 1) ? "verified" : "unverified"); key_free(key); free(blob); free(signature); free(data); auth_method = key_blobtype == MM_USERKEY ? "publickey" : "hostbased"; monitor_reset_key_state(); buffer_clear(m); buffer_put_int(m, verified); mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m); return (verified == 1); } static void mm_record_login(Session *s, struct passwd *pw) { socklen_t fromlen; struct sockaddr_storage from; /* * Get IP address of client. If the connection is not a socket, let * the address be 0.0.0.0. */ memset(&from, 0, sizeof(from)); fromlen = sizeof(from); if (packet_connection_is_on_socket()) { if (getpeername(packet_get_connection_in(), (struct sockaddr *)&from, &fromlen) < 0) { debug("getpeername: %.100s", strerror(errno)); cleanup_exit(255); } } /* Record that there was a login on that tty from the remote host. */ record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid, get_remote_name_or_ip(utmp_len, options.use_dns), (struct sockaddr *)&from, fromlen); } static void mm_session_close(Session *s) { debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); if (s->ttyfd != -1) { debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); session_pty_cleanup2(s); } session_unused(s->self); } int mm_answer_pty(int sock, Buffer *m) { extern struct monitor *pmonitor; Session *s; int res, fd0; debug3("%s entering", __func__); buffer_clear(m); s = session_new(); if (s == NULL) goto error; s->authctxt = authctxt; s->pw = authctxt->pw; s->pid = pmonitor->m_pid; res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)); if (res == 0) goto error; pty_setowner(authctxt->pw, s->tty); buffer_put_int(m, 1); buffer_put_cstring(m, s->tty); /* We need to trick ttyslot */ if (dup2(s->ttyfd, 0) == -1) fatal("%s: dup2", __func__); mm_record_login(s, authctxt->pw); /* Now we can close the file descriptor again */ close(0); /* send messages generated by record_login */ buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg)); buffer_clear(&loginmsg); mm_request_send(sock, MONITOR_ANS_PTY, m); if (mm_send_fd(sock, s->ptyfd) == -1 || mm_send_fd(sock, s->ttyfd) == -1) fatal("%s: send fds failed", __func__); /* make sure nothing uses fd 0 */ if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0) fatal("%s: open(/dev/null): %s", __func__, strerror(errno)); if (fd0 != 0) error("%s: fd0 %d != 0", __func__, fd0); /* slave is not needed */ close(s->ttyfd); s->ttyfd = s->ptyfd; /* no need to dup() because nobody closes ptyfd */ s->ptymaster = s->ptyfd; debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ttyfd); return (0); error: if (s != NULL) mm_session_close(s); buffer_put_int(m, 0); mm_request_send(sock, MONITOR_ANS_PTY, m); return (0); } int mm_answer_pty_cleanup(int sock, Buffer *m) { Session *s; char *tty; debug3("%s entering", __func__); tty = buffer_get_string(m, NULL); if ((s = session_by_tty(tty)) != NULL) mm_session_close(s); buffer_clear(m); free(tty); return (0); } int mm_answer_sesskey(int sock, Buffer *m) { BIGNUM *p; int rsafail; /* Turn off permissions */ monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 0); if ((p = BN_new()) == NULL) fatal("%s: BN_new", __func__); buffer_get_bignum2(m, p); rsafail = ssh1_session_key(p); buffer_clear(m); buffer_put_int(m, rsafail); buffer_put_bignum2(m, p); BN_clear_free(p); mm_request_send(sock, MONITOR_ANS_SESSKEY, m); /* Turn on permissions for sessid passing */ monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1); return (0); } int mm_answer_sessid(int sock, Buffer *m) { int i; debug3("%s entering", __func__); if (buffer_len(m) != 16) fatal("%s: bad ssh1 session id", __func__); for (i = 0; i < 16; i++) session_id[i] = buffer_get_char(m); /* Turn on permissions for getpwnam */ monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1); return (0); } int mm_answer_rsa_keyallowed(int sock, Buffer *m) { BIGNUM *client_n; Key *key = NULL; u_char *blob = NULL; u_int blen = 0; int allowed = 0; debug3("%s entering", __func__); auth_method = "rsa"; if (options.rsa_authentication && authctxt->valid) { if ((client_n = BN_new()) == NULL) fatal("%s: BN_new", __func__); buffer_get_bignum2(m, client_n); allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key); BN_clear_free(client_n); } buffer_clear(m); buffer_put_int(m, allowed); buffer_put_int(m, forced_command != NULL); /* clear temporarily storage (used by generate challenge) */ monitor_reset_key_state(); if (allowed && key != NULL) { key->type = KEY_RSA; /* cheat for key_to_blob */ if (key_to_blob(key, &blob, &blen) == 0) fatal("%s: key_to_blob failed", __func__); buffer_put_string(m, blob, blen); /* Save temporarily for comparison in verify */ key_blob = blob; key_bloblen = blen; key_blobtype = MM_RSAUSERKEY; } if (key != NULL) key_free(key); mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m); monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed); monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0); return (0); } int mm_answer_rsa_challenge(int sock, Buffer *m) { Key *key = NULL; u_char *blob; u_int blen; debug3("%s entering", __func__); if (!authctxt->valid) fatal("%s: authctxt not valid", __func__); blob = buffer_get_string(m, &blen); if (!monitor_allowed_key(blob, blen)) fatal("%s: bad key, not previously allowed", __func__); if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) fatal("%s: key type mismatch", __func__); if ((key = key_from_blob(blob, blen)) == NULL) fatal("%s: received bad key", __func__); if (key->type != KEY_RSA) fatal("%s: received bad key type %d", __func__, key->type); key->type = KEY_RSA1; if (ssh1_challenge) BN_clear_free(ssh1_challenge); ssh1_challenge = auth_rsa_generate_challenge(key); buffer_clear(m); buffer_put_bignum2(m, ssh1_challenge); debug3("%s sending reply", __func__); mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m); monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1); free(blob); key_free(key); return (0); } int mm_answer_rsa_response(int sock, Buffer *m) { Key *key = NULL; u_char *blob, *response; u_int blen, len; int success; debug3("%s entering", __func__); if (!authctxt->valid) fatal("%s: authctxt not valid", __func__); if (ssh1_challenge == NULL) fatal("%s: no ssh1_challenge", __func__); blob = buffer_get_string(m, &blen); if (!monitor_allowed_key(blob, blen)) fatal("%s: bad key, not previously allowed", __func__); if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY) fatal("%s: key type mismatch: %d", __func__, key_blobtype); if ((key = key_from_blob(blob, blen)) == NULL) fatal("%s: received bad key", __func__); response = buffer_get_string(m, &len); if (len != 16) fatal("%s: received bad response to challenge", __func__); success = auth_rsa_verify_response(key, ssh1_challenge, response); free(blob); key_free(key); free(response); auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa"; /* reset state */ BN_clear_free(ssh1_challenge); ssh1_challenge = NULL; monitor_reset_key_state(); buffer_clear(m); buffer_put_int(m, success); mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m); return (success); } int mm_answer_term(int sock, Buffer *req) { extern struct monitor *pmonitor; int res, status; debug3("%s: tearing down sessions", __func__); /* The child is terminating */ session_destroy_all(&mm_session_close); #ifdef USE_PAM if (options.use_pam) sshpam_cleanup(); #endif while (waitpid(pmonitor->m_pid, &status, 0) == -1) if (errno != EINTR) exit(1); res = WIFEXITED(status) ? WEXITSTATUS(status) : 1; /* Terminate process */ exit(res); } #ifdef SSH_AUDIT_EVENTS /* Report that an audit event occurred */ int mm_answer_audit_event(int socket, Buffer *m) { ssh_audit_event_t event; debug3("%s entering", __func__); event = buffer_get_int(m); switch(event) { case SSH_AUTH_FAIL_PUBKEY: case SSH_AUTH_FAIL_HOSTBASED: case SSH_AUTH_FAIL_GSSAPI: case SSH_LOGIN_EXCEED_MAXTRIES: case SSH_LOGIN_ROOT_DENIED: case SSH_CONNECTION_CLOSE: case SSH_INVALID_USER: audit_event(event); break; default: fatal("Audit event type %d not permitted", event); } return (0); } int mm_answer_audit_command(int socket, Buffer *m) { u_int len; char *cmd; debug3("%s entering", __func__); cmd = buffer_get_string(m, &len); /* sanity check command, if so how? */ audit_run_command(cmd); free(cmd); return (0); } #endif /* SSH_AUDIT_EVENTS */ void monitor_apply_keystate(struct monitor *pmonitor) { if (compat20) { set_newkeys(MODE_IN); set_newkeys(MODE_OUT); } else { packet_set_protocol_flags(child_state.ssh1protoflags); packet_set_encryption_key(child_state.ssh1key, child_state.ssh1keylen, child_state.ssh1cipher); free(child_state.ssh1key); } /* for rc4 and other stateful ciphers */ packet_set_keycontext(MODE_OUT, child_state.keyout); free(child_state.keyout); packet_set_keycontext(MODE_IN, child_state.keyin); free(child_state.keyin); if (!compat20) { packet_set_iv(MODE_OUT, child_state.ivout); free(child_state.ivout); packet_set_iv(MODE_IN, child_state.ivin); free(child_state.ivin); } memcpy(&incoming_stream, &child_state.incoming, sizeof(incoming_stream)); memcpy(&outgoing_stream, &child_state.outgoing, sizeof(outgoing_stream)); /* Update with new address */ if (options.compression) mm_init_compression(pmonitor->m_zlib); if (options.rekey_limit || options.rekey_interval) packet_set_rekey_limits((u_int32_t)options.rekey_limit, (time_t)options.rekey_interval); /* Network I/O buffers */ /* XXX inefficient for large buffers, need: buffer_init_from_string */ buffer_clear(packet_get_input()); buffer_append(packet_get_input(), child_state.input, child_state.ilen); explicit_bzero(child_state.input, child_state.ilen); free(child_state.input); buffer_clear(packet_get_output()); buffer_append(packet_get_output(), child_state.output, child_state.olen); explicit_bzero(child_state.output, child_state.olen); free(child_state.output); /* Roaming */ if (compat20) roam_set_bytes(child_state.sent_bytes, child_state.recv_bytes); } static Kex * mm_get_kex(Buffer *m) { Kex *kex; void *blob; u_int bloblen; kex = xcalloc(1, sizeof(*kex)); kex->session_id = buffer_get_string(m, &kex->session_id_len); if (session_id2 == NULL || kex->session_id_len != session_id2_len || timingsafe_bcmp(kex->session_id, session_id2, session_id2_len) != 0) fatal("mm_get_get: internal error: bad session id"); kex->we_need = buffer_get_int(m); 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; kex->kex[KEX_ECDH_SHA2] = kexecdh_server; kex->kex[KEX_C25519_SHA256] = kexc25519_server; kex->server = 1; kex->hostkey_type = buffer_get_int(m); kex->kex_type = buffer_get_int(m); blob = buffer_get_string(m, &bloblen); buffer_init(&kex->my); buffer_append(&kex->my, blob, bloblen); free(blob); blob = buffer_get_string(m, &bloblen); buffer_init(&kex->peer); buffer_append(&kex->peer, blob, bloblen); free(blob); kex->done = 1; kex->flags = buffer_get_int(m); kex->client_version_string = buffer_get_string(m, NULL); kex->server_version_string = buffer_get_string(m, NULL); 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; return (kex); } /* This function requries careful sanity checking */ void mm_get_keystate(struct monitor *pmonitor) { Buffer m; u_char *blob, *p; u_int bloblen, plen; u_int32_t seqnr, packets; u_int64_t blocks, bytes; debug3("%s: Waiting for new keys", __func__); buffer_init(&m); mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, &m); if (!compat20) { child_state.ssh1protoflags = buffer_get_int(&m); child_state.ssh1cipher = buffer_get_int(&m); child_state.ssh1key = buffer_get_string(&m, &child_state.ssh1keylen); child_state.ivout = buffer_get_string(&m, &child_state.ivoutlen); child_state.ivin = buffer_get_string(&m, &child_state.ivinlen); goto skip; } else { /* Get the Kex for rekeying */ *pmonitor->m_pkex = mm_get_kex(&m); } blob = buffer_get_string(&m, &bloblen); current_keys[MODE_OUT] = mm_newkeys_from_blob(blob, bloblen); free(blob); debug3("%s: Waiting for second key", __func__); blob = buffer_get_string(&m, &bloblen); current_keys[MODE_IN] = mm_newkeys_from_blob(blob, bloblen); free(blob); /* Now get sequence numbers for the packets */ seqnr = buffer_get_int(&m); blocks = buffer_get_int64(&m); packets = buffer_get_int(&m); bytes = buffer_get_int64(&m); packet_set_state(MODE_OUT, seqnr, blocks, packets, bytes); seqnr = buffer_get_int(&m); blocks = buffer_get_int64(&m); packets = buffer_get_int(&m); bytes = buffer_get_int64(&m); packet_set_state(MODE_IN, seqnr, blocks, packets, bytes); skip: /* Get the key context */ child_state.keyout = buffer_get_string(&m, &child_state.keyoutlen); child_state.keyin = buffer_get_string(&m, &child_state.keyinlen); debug3("%s: Getting compression state", __func__); /* Get compression state */ p = buffer_get_string(&m, &plen); if (plen != sizeof(child_state.outgoing)) fatal("%s: bad request size", __func__); memcpy(&child_state.outgoing, p, sizeof(child_state.outgoing)); free(p); p = buffer_get_string(&m, &plen); if (plen != sizeof(child_state.incoming)) fatal("%s: bad request size", __func__); memcpy(&child_state.incoming, p, sizeof(child_state.incoming)); free(p); /* Network I/O buffers */ debug3("%s: Getting Network I/O buffers", __func__); child_state.input = buffer_get_string(&m, &child_state.ilen); child_state.output = buffer_get_string(&m, &child_state.olen); /* Roaming */ if (compat20) { child_state.sent_bytes = buffer_get_int64(&m); child_state.recv_bytes = buffer_get_int64(&m); } buffer_free(&m); } /* Allocation functions for zlib */ void * mm_zalloc(struct mm_master *mm, u_int ncount, u_int size) { size_t len = (size_t) size * ncount; void *address; if (len == 0 || ncount > SIZE_T_MAX / size) fatal("%s: mm_zalloc(%u, %u)", __func__, ncount, size); address = mm_malloc(mm, len); return (address); } void mm_zfree(struct mm_master *mm, void *address) { mm_free(mm, address); } void mm_init_compression(struct mm_master *mm) { outgoing_stream.zalloc = (alloc_func)mm_zalloc; outgoing_stream.zfree = (free_func)mm_zfree; outgoing_stream.opaque = mm; incoming_stream.zalloc = (alloc_func)mm_zalloc; incoming_stream.zfree = (free_func)mm_zfree; incoming_stream.opaque = mm; } /* XXX */ #define FD_CLOSEONEXEC(x) do { \ if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \ fatal("fcntl(%d, F_SETFD)", x); \ } while (0) static void monitor_openfds(struct monitor *mon, int do_logfds) { int pair[2]; if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) fatal("%s: socketpair: %s", __func__, strerror(errno)); FD_CLOSEONEXEC(pair[0]); FD_CLOSEONEXEC(pair[1]); mon->m_recvfd = pair[0]; mon->m_sendfd = pair[1]; if (do_logfds) { if (pipe(pair) == -1) fatal("%s: pipe: %s", __func__, strerror(errno)); FD_CLOSEONEXEC(pair[0]); FD_CLOSEONEXEC(pair[1]); mon->m_log_recvfd = pair[0]; mon->m_log_sendfd = pair[1]; } else mon->m_log_recvfd = mon->m_log_sendfd = -1; } #define MM_MEMSIZE 65536 struct monitor * monitor_init(void) { struct monitor *mon; mon = xcalloc(1, sizeof(*mon)); monitor_openfds(mon, 1); /* Used to share zlib space across processes */ if (options.compression) { mon->m_zback = mm_create(NULL, MM_MEMSIZE); mon->m_zlib = mm_create(mon->m_zback, 20 * MM_MEMSIZE); /* Compression needs to share state across borders */ mm_init_compression(mon->m_zlib); } return mon; } void monitor_reinit(struct monitor *mon) { monitor_openfds(mon, 0); } #ifdef GSSAPI int mm_answer_gss_setup_ctx(int sock, Buffer *m) { gss_OID_desc goid; OM_uint32 major; u_int len; goid.elements = buffer_get_string(m, &len); goid.length = len; major = ssh_gssapi_server_ctx(&gsscontext, &goid); free(goid.elements); buffer_clear(m); buffer_put_int(m, major); mm_request_send(sock, MONITOR_ANS_GSSSETUP, m); /* Now we have a context, enable the step */ monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); return (0); } int mm_answer_gss_accept_ctx(int sock, Buffer *m) { gss_buffer_desc in; gss_buffer_desc out = GSS_C_EMPTY_BUFFER; OM_uint32 major, minor; OM_uint32 flags = 0; /* GSI needs this */ u_int len; in.value = buffer_get_string(m, &len); in.length = len; major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); free(in.value); buffer_clear(m); buffer_put_int(m, major); buffer_put_string(m, out.value, out.length); buffer_put_int(m, flags); mm_request_send(sock, MONITOR_ANS_GSSSTEP, m); gss_release_buffer(&minor, &out); if (major == GSS_S_COMPLETE) { monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1); } return (0); } int mm_answer_gss_checkmic(int sock, Buffer *m) { gss_buffer_desc gssbuf, mic; OM_uint32 ret; u_int len; gssbuf.value = buffer_get_string(m, &len); gssbuf.length = len; mic.value = buffer_get_string(m, &len); mic.length = len; ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic); free(gssbuf.value); free(mic.value); buffer_clear(m); buffer_put_int(m, ret); mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m); if (!GSS_ERROR(ret)) monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); return (0); } int mm_answer_gss_userok(int sock, Buffer *m) { int authenticated; authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); buffer_clear(m); buffer_put_int(m, authenticated); debug3("%s: sending result %d", __func__, authenticated); mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m); auth_method = "gssapi-with-mic"; /* Monitor loop will terminate if authenticated */ return (authenticated); } #endif /* GSSAPI */ Index: head/crypto/openssh/monitor_wrap.c =================================================================== --- head/crypto/openssh/monitor_wrap.c (revision 287142) +++ head/crypto/openssh/monitor_wrap.c (revision 287143) @@ -1,1292 +1,1291 @@ /* $OpenBSD: monitor_wrap.c,v 1.79 2014/02/02 03:44:31 djm Exp $ */ /* * Copyright 2002 Niels Provos * Copyright 2002 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" #include #include #include #include #include #include #include #include #include #include #include #include #include "openbsd-compat/sys-queue.h" #include "xmalloc.h" #include "ssh.h" #include "dh.h" #include "buffer.h" #include "key.h" #include "cipher.h" #include "kex.h" #include "hostfile.h" #include "auth.h" #include "auth-options.h" #include "packet.h" #include "mac.h" #include "log.h" #ifdef TARGET_OS_MAC /* XXX Broken krb5 headers on Mac */ #undef TARGET_OS_MAC #include "zlib.h" #define TARGET_OS_MAC 1 #else #include "zlib.h" #endif #include "monitor.h" #ifdef GSSAPI #include "ssh-gss.h" #endif #include "monitor_wrap.h" #include "atomicio.h" #include "monitor_fdpass.h" #include "misc.h" #include "uuencode.h" #include "channels.h" #include "session.h" #include "servconf.h" #include "roaming.h" /* Imports */ extern int compat20; extern z_stream incoming_stream; extern z_stream outgoing_stream; extern struct monitor *pmonitor; extern Buffer loginmsg; extern ServerOptions options; void mm_log_handler(LogLevel level, const char *msg, void *ctx) { Buffer log_msg; struct monitor *mon = (struct monitor *)ctx; if (mon->m_log_sendfd == -1) fatal("%s: no log channel", __func__); buffer_init(&log_msg); /* * Placeholder for packet length. Will be filled in with the actual * packet length once the packet has been constucted. This saves * fragile math. */ buffer_put_int(&log_msg, 0); buffer_put_int(&log_msg, level); buffer_put_cstring(&log_msg, msg); put_u32(buffer_ptr(&log_msg), buffer_len(&log_msg) - 4); if (atomicio(vwrite, mon->m_log_sendfd, buffer_ptr(&log_msg), buffer_len(&log_msg)) != buffer_len(&log_msg)) fatal("%s: write: %s", __func__, strerror(errno)); buffer_free(&log_msg); } int mm_is_monitor(void) { /* * m_pid is only set in the privileged part, and * points to the unprivileged child. */ return (pmonitor && pmonitor->m_pid > 0); } void mm_request_send(int sock, enum monitor_reqtype type, Buffer *m) { u_int mlen = buffer_len(m); u_char buf[5]; debug3("%s entering: type %d", __func__, type); put_u32(buf, mlen + 1); buf[4] = (u_char) type; /* 1st byte of payload is mesg-type */ if (atomicio(vwrite, sock, buf, sizeof(buf)) != sizeof(buf)) fatal("%s: write: %s", __func__, strerror(errno)); if (atomicio(vwrite, sock, buffer_ptr(m), mlen) != mlen) fatal("%s: write: %s", __func__, strerror(errno)); } void mm_request_receive(int sock, Buffer *m) { u_char buf[4]; u_int msg_len; debug3("%s entering", __func__); if (atomicio(read, sock, buf, sizeof(buf)) != sizeof(buf)) { if (errno == EPIPE) cleanup_exit(255); fatal("%s: read: %s", __func__, strerror(errno)); } msg_len = get_u32(buf); if (msg_len > 256 * 1024) fatal("%s: read: bad msg_len %d", __func__, msg_len); buffer_clear(m); buffer_append_space(m, msg_len); if (atomicio(read, sock, buffer_ptr(m), msg_len) != msg_len) fatal("%s: read: %s", __func__, strerror(errno)); } void mm_request_receive_expect(int sock, enum monitor_reqtype type, Buffer *m) { u_char rtype; debug3("%s entering: type %d", __func__, type); mm_request_receive(sock, m); rtype = buffer_get_char(m); if (rtype != type) fatal("%s: read: rtype %d != type %d", __func__, rtype, type); } DH * mm_choose_dh(int min, int nbits, int max) { BIGNUM *p, *g; int success = 0; Buffer m; buffer_init(&m); buffer_put_int(&m, min); buffer_put_int(&m, nbits); buffer_put_int(&m, max); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_MODULI, &m); debug3("%s: waiting for MONITOR_ANS_MODULI", __func__); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_MODULI, &m); success = buffer_get_char(&m); if (success == 0) fatal("%s: MONITOR_ANS_MODULI failed", __func__); if ((p = BN_new()) == NULL) fatal("%s: BN_new failed", __func__); if ((g = BN_new()) == NULL) fatal("%s: BN_new failed", __func__); buffer_get_bignum2(&m, p); buffer_get_bignum2(&m, g); debug3("%s: remaining %d", __func__, buffer_len(&m)); buffer_free(&m); return (dh_new_group(g, p)); } int mm_key_sign(Key *key, u_char **sigp, u_int *lenp, u_char *data, u_int datalen) { Kex *kex = *pmonitor->m_pkex; Buffer m; debug3("%s entering", __func__); buffer_init(&m); buffer_put_int(&m, kex->host_key_index(key)); buffer_put_string(&m, data, datalen); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, &m); debug3("%s: waiting for MONITOR_ANS_SIGN", __func__); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, &m); *sigp = buffer_get_string(&m, lenp); buffer_free(&m); return (0); } struct passwd * mm_getpwnamallow(const char *username) { Buffer m; struct passwd *pw; u_int len, i; ServerOptions *newopts; debug3("%s entering", __func__); buffer_init(&m); buffer_put_cstring(&m, username); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, &m); debug3("%s: waiting for MONITOR_ANS_PWNAM", __func__); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, &m); if (buffer_get_char(&m) == 0) { pw = NULL; goto out; } pw = buffer_get_string(&m, &len); if (len != sizeof(struct passwd)) fatal("%s: struct passwd size mismatch", __func__); pw->pw_name = buffer_get_string(&m, NULL); pw->pw_passwd = buffer_get_string(&m, NULL); #ifdef HAVE_STRUCT_PASSWD_PW_GECOS pw->pw_gecos = buffer_get_string(&m, NULL); #endif #ifdef HAVE_STRUCT_PASSWD_PW_CLASS pw->pw_class = buffer_get_string(&m, NULL); #endif pw->pw_dir = buffer_get_string(&m, NULL); pw->pw_shell = buffer_get_string(&m, NULL); out: /* copy options block as a Match directive may have changed some */ newopts = buffer_get_string(&m, &len); if (len != sizeof(*newopts)) fatal("%s: option block size mismatch", __func__); #define M_CP_STROPT(x) do { \ if (newopts->x != NULL) \ newopts->x = buffer_get_string(&m, NULL); \ } while (0) #define M_CP_STRARRAYOPT(x, nx) do { \ for (i = 0; i < newopts->nx; i++) \ newopts->x[i] = buffer_get_string(&m, NULL); \ } while (0) /* See comment in servconf.h */ COPY_MATCH_STRING_OPTS(); #undef M_CP_STROPT #undef M_CP_STRARRAYOPT copy_set_server_options(&options, newopts, 1); free(newopts); buffer_free(&m); return (pw); } char * mm_auth2_read_banner(void) { Buffer m; char *banner; debug3("%s entering", __func__); buffer_init(&m); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, &m); buffer_clear(&m); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_AUTH2_READ_BANNER, &m); banner = buffer_get_string(&m, NULL); buffer_free(&m); /* treat empty banner as missing banner */ if (strlen(banner) == 0) { free(banner); banner = NULL; } return (banner); } /* Inform the privileged process about service and style */ void mm_inform_authserv(char *service, char *style) { Buffer m; debug3("%s entering", __func__); buffer_init(&m); buffer_put_cstring(&m, service); buffer_put_cstring(&m, style ? style : ""); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, &m); buffer_free(&m); } /* Do the password authentication */ int mm_auth_password(Authctxt *authctxt, char *password) { Buffer m; int authenticated = 0; debug3("%s entering", __func__); buffer_init(&m); buffer_put_cstring(&m, password); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, &m); debug3("%s: waiting for MONITOR_ANS_AUTHPASSWORD", __func__); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_AUTHPASSWORD, &m); authenticated = buffer_get_int(&m); buffer_free(&m); debug3("%s: user %sauthenticated", __func__, authenticated ? "" : "not "); return (authenticated); } int mm_user_key_allowed(struct passwd *pw, Key *key) { return (mm_key_allowed(MM_USERKEY, NULL, NULL, key)); } int mm_hostbased_key_allowed(struct passwd *pw, char *user, char *host, Key *key) { return (mm_key_allowed(MM_HOSTKEY, user, host, key)); } int mm_auth_rhosts_rsa_key_allowed(struct passwd *pw, char *user, char *host, Key *key) { int ret; key->type = KEY_RSA; /* XXX hack for key_to_blob */ ret = mm_key_allowed(MM_RSAHOSTKEY, user, host, key); key->type = KEY_RSA1; return (ret); } int mm_key_allowed(enum mm_keytype type, char *user, char *host, Key *key) { Buffer m; u_char *blob; u_int len; int allowed = 0, have_forced = 0; debug3("%s entering", __func__); /* Convert the key to a blob and the pass it over */ if (!key_to_blob(key, &blob, &len)) return (0); buffer_init(&m); buffer_put_int(&m, type); buffer_put_cstring(&m, user ? user : ""); buffer_put_cstring(&m, host ? host : ""); buffer_put_string(&m, blob, len); free(blob); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, &m); debug3("%s: waiting for MONITOR_ANS_KEYALLOWED", __func__); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KEYALLOWED, &m); allowed = buffer_get_int(&m); /* fake forced command */ auth_clear_options(); have_forced = buffer_get_int(&m); forced_command = have_forced ? xstrdup("true") : NULL; buffer_free(&m); return (allowed); } /* * This key verify needs to send the key type along, because the * privileged parent makes the decision if the key is allowed * for authentication. */ int mm_key_verify(Key *key, u_char *sig, u_int siglen, u_char *data, u_int datalen) { Buffer m; u_char *blob; u_int len; int verified = 0; debug3("%s entering", __func__); /* Convert the key to a blob and the pass it over */ if (!key_to_blob(key, &blob, &len)) return (0); buffer_init(&m); buffer_put_string(&m, blob, len); buffer_put_string(&m, sig, siglen); buffer_put_string(&m, data, datalen); free(blob); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, &m); debug3("%s: waiting for MONITOR_ANS_KEYVERIFY", __func__); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KEYVERIFY, &m); verified = buffer_get_int(&m); buffer_free(&m); return (verified); } /* Export key state after authentication */ Newkeys * mm_newkeys_from_blob(u_char *blob, int blen) { Buffer b; u_int len; Newkeys *newkey = NULL; Enc *enc; Mac *mac; Comp *comp; debug3("%s: %p(%d)", __func__, blob, blen); #ifdef DEBUG_PK dump_base64(stderr, blob, blen); #endif buffer_init(&b); buffer_append(&b, blob, blen); newkey = xcalloc(1, sizeof(*newkey)); enc = &newkey->enc; mac = &newkey->mac; comp = &newkey->comp; /* Enc structure */ enc->name = buffer_get_string(&b, NULL); buffer_get(&b, &enc->cipher, sizeof(enc->cipher)); enc->enabled = buffer_get_int(&b); enc->block_size = buffer_get_int(&b); enc->key = buffer_get_string(&b, &enc->key_len); enc->iv = buffer_get_string(&b, &enc->iv_len); if (enc->name == NULL || cipher_by_name(enc->name) != enc->cipher) fatal("%s: bad cipher name %s or pointer %p", __func__, enc->name, enc->cipher); /* Mac structure */ if (cipher_authlen(enc->cipher) == 0) { mac->name = buffer_get_string(&b, NULL); if (mac->name == NULL || mac_setup(mac, mac->name) == -1) fatal("%s: can not setup mac %s", __func__, mac->name); mac->enabled = buffer_get_int(&b); mac->key = buffer_get_string(&b, &len); if (len > mac->key_len) fatal("%s: bad mac key length: %u > %d", __func__, len, mac->key_len); mac->key_len = len; } /* Comp structure */ comp->type = buffer_get_int(&b); comp->enabled = buffer_get_int(&b); comp->name = buffer_get_string(&b, NULL); len = buffer_len(&b); if (len != 0) error("newkeys_from_blob: remaining bytes in blob %u", len); buffer_free(&b); return (newkey); } int mm_newkeys_to_blob(int mode, u_char **blobp, u_int *lenp) { Buffer b; int len; Enc *enc; Mac *mac; Comp *comp; Newkeys *newkey = (Newkeys *)packet_get_newkeys(mode); debug3("%s: converting %p", __func__, newkey); if (newkey == NULL) { error("%s: newkey == NULL", __func__); return 0; } enc = &newkey->enc; mac = &newkey->mac; comp = &newkey->comp; buffer_init(&b); /* Enc structure */ buffer_put_cstring(&b, enc->name); /* The cipher struct is constant and shared, you export pointer */ buffer_append(&b, &enc->cipher, sizeof(enc->cipher)); buffer_put_int(&b, enc->enabled); buffer_put_int(&b, enc->block_size); buffer_put_string(&b, enc->key, enc->key_len); packet_get_keyiv(mode, enc->iv, enc->iv_len); buffer_put_string(&b, enc->iv, enc->iv_len); /* Mac structure */ if (cipher_authlen(enc->cipher) == 0) { buffer_put_cstring(&b, mac->name); buffer_put_int(&b, mac->enabled); buffer_put_string(&b, mac->key, mac->key_len); } /* Comp structure */ buffer_put_int(&b, comp->type); buffer_put_int(&b, comp->enabled); buffer_put_cstring(&b, comp->name); len = buffer_len(&b); if (lenp != NULL) *lenp = len; if (blobp != NULL) { *blobp = xmalloc(len); memcpy(*blobp, buffer_ptr(&b), len); } explicit_bzero(buffer_ptr(&b), len); buffer_free(&b); return len; } static void mm_send_kex(Buffer *m, Kex *kex) { buffer_put_string(m, kex->session_id, kex->session_id_len); buffer_put_int(m, kex->we_need); buffer_put_int(m, kex->hostkey_type); buffer_put_int(m, kex->kex_type); buffer_put_string(m, buffer_ptr(&kex->my), buffer_len(&kex->my)); buffer_put_string(m, buffer_ptr(&kex->peer), buffer_len(&kex->peer)); buffer_put_int(m, kex->flags); buffer_put_cstring(m, kex->client_version_string); buffer_put_cstring(m, kex->server_version_string); } void mm_send_keystate(struct monitor *monitor) { Buffer m, *input, *output; u_char *blob, *p; u_int bloblen, plen; u_int32_t seqnr, packets; u_int64_t blocks, bytes; buffer_init(&m); if (!compat20) { u_char iv[24]; u_char *key; u_int ivlen, keylen; buffer_put_int(&m, packet_get_protocol_flags()); buffer_put_int(&m, packet_get_ssh1_cipher()); debug3("%s: Sending ssh1 KEY+IV", __func__); keylen = packet_get_encryption_key(NULL); key = xmalloc(keylen+1); /* add 1 if keylen == 0 */ keylen = packet_get_encryption_key(key); buffer_put_string(&m, key, keylen); explicit_bzero(key, keylen); free(key); ivlen = packet_get_keyiv_len(MODE_OUT); packet_get_keyiv(MODE_OUT, iv, ivlen); buffer_put_string(&m, iv, ivlen); ivlen = packet_get_keyiv_len(MODE_IN); packet_get_keyiv(MODE_IN, iv, ivlen); buffer_put_string(&m, iv, ivlen); goto skip; } else { /* Kex for rekeying */ mm_send_kex(&m, *monitor->m_pkex); } debug3("%s: Sending new keys: %p %p", __func__, packet_get_newkeys(MODE_OUT), packet_get_newkeys(MODE_IN)); /* Keys from Kex */ if (!mm_newkeys_to_blob(MODE_OUT, &blob, &bloblen)) fatal("%s: conversion of newkeys failed", __func__); buffer_put_string(&m, blob, bloblen); free(blob); if (!mm_newkeys_to_blob(MODE_IN, &blob, &bloblen)) fatal("%s: conversion of newkeys failed", __func__); buffer_put_string(&m, blob, bloblen); free(blob); packet_get_state(MODE_OUT, &seqnr, &blocks, &packets, &bytes); buffer_put_int(&m, seqnr); buffer_put_int64(&m, blocks); buffer_put_int(&m, packets); buffer_put_int64(&m, bytes); packet_get_state(MODE_IN, &seqnr, &blocks, &packets, &bytes); buffer_put_int(&m, seqnr); buffer_put_int64(&m, blocks); buffer_put_int(&m, packets); buffer_put_int64(&m, bytes); debug3("%s: New keys have been sent", __func__); skip: /* More key context */ plen = packet_get_keycontext(MODE_OUT, NULL); p = xmalloc(plen+1); packet_get_keycontext(MODE_OUT, p); buffer_put_string(&m, p, plen); free(p); plen = packet_get_keycontext(MODE_IN, NULL); p = xmalloc(plen+1); packet_get_keycontext(MODE_IN, p); buffer_put_string(&m, p, plen); free(p); /* Compression state */ debug3("%s: Sending compression state", __func__); buffer_put_string(&m, &outgoing_stream, sizeof(outgoing_stream)); buffer_put_string(&m, &incoming_stream, sizeof(incoming_stream)); /* Network I/O buffers */ input = (Buffer *)packet_get_input(); output = (Buffer *)packet_get_output(); buffer_put_string(&m, buffer_ptr(input), buffer_len(input)); buffer_put_string(&m, buffer_ptr(output), buffer_len(output)); /* Roaming */ if (compat20) { buffer_put_int64(&m, get_sent_bytes()); buffer_put_int64(&m, get_recv_bytes()); } mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, &m); debug3("%s: Finished sending state", __func__); buffer_free(&m); } int mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen) { Buffer m; char *p, *msg; int success = 0, tmp1 = -1, tmp2 = -1; /* Kludge: ensure there are fds free to receive the pty/tty */ if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 || (tmp2 = dup(pmonitor->m_recvfd)) == -1) { error("%s: cannot allocate fds for pty", __func__); if (tmp1 > 0) close(tmp1); if (tmp2 > 0) close(tmp2); return 0; } close(tmp1); close(tmp2); buffer_init(&m); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, &m); debug3("%s: waiting for MONITOR_ANS_PTY", __func__); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, &m); success = buffer_get_int(&m); if (success == 0) { debug3("%s: pty alloc failed", __func__); buffer_free(&m); return (0); } p = buffer_get_string(&m, NULL); msg = buffer_get_string(&m, NULL); buffer_free(&m); strlcpy(namebuf, p, namebuflen); /* Possible truncation */ free(p); buffer_append(&loginmsg, msg, strlen(msg)); free(msg); if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 || (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1) fatal("%s: receive fds failed", __func__); /* Success */ return (1); } void mm_session_pty_cleanup2(Session *s) { Buffer m; if (s->ttyfd == -1) return; buffer_init(&m); buffer_put_cstring(&m, s->tty); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, &m); buffer_free(&m); /* closed dup'ed master */ if (s->ptymaster != -1 && close(s->ptymaster) < 0) error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno)); /* unlink pty from session */ s->ttyfd = -1; } #ifdef USE_PAM void mm_start_pam(Authctxt *authctxt) { Buffer m; debug3("%s entering", __func__); if (!options.use_pam) fatal("UsePAM=no, but ended up in %s anyway", __func__); buffer_init(&m); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, &m); buffer_free(&m); } u_int mm_do_pam_account(void) { Buffer m; u_int ret; char *msg; debug3("%s entering", __func__); if (!options.use_pam) fatal("UsePAM=no, but ended up in %s anyway", __func__); buffer_init(&m); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, &m); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_ACCOUNT, &m); ret = buffer_get_int(&m); msg = buffer_get_string(&m, NULL); buffer_append(&loginmsg, msg, strlen(msg)); free(msg); buffer_free(&m); debug3("%s returning %d", __func__, ret); return (ret); } void * mm_sshpam_init_ctx(Authctxt *authctxt) { Buffer m; int success; debug3("%s", __func__); buffer_init(&m); - buffer_put_cstring(&m, authctxt->user); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, &m); debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_INIT_CTX, &m); success = buffer_get_int(&m); if (success == 0) { debug3("%s: pam_init_ctx failed", __func__); buffer_free(&m); return (NULL); } buffer_free(&m); return (authctxt); } int mm_sshpam_query(void *ctx, char **name, char **info, u_int *num, char ***prompts, u_int **echo_on) { Buffer m; u_int i; int ret; debug3("%s", __func__); buffer_init(&m); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_QUERY, &m); debug3("%s: waiting for MONITOR_ANS_PAM_QUERY", __func__); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_QUERY, &m); ret = buffer_get_int(&m); debug3("%s: pam_query returned %d", __func__, ret); *name = buffer_get_string(&m, NULL); *info = buffer_get_string(&m, NULL); *num = buffer_get_int(&m); if (*num > PAM_MAX_NUM_MSG) fatal("%s: recieved %u PAM messages, expected <= %u", __func__, *num, PAM_MAX_NUM_MSG); *prompts = xcalloc((*num + 1), sizeof(char *)); *echo_on = xcalloc((*num + 1), sizeof(u_int)); for (i = 0; i < *num; ++i) { (*prompts)[i] = buffer_get_string(&m, NULL); (*echo_on)[i] = buffer_get_int(&m); } buffer_free(&m); return (ret); } int mm_sshpam_respond(void *ctx, u_int num, char **resp) { Buffer m; u_int i; int ret; debug3("%s", __func__); buffer_init(&m); buffer_put_int(&m, num); for (i = 0; i < num; ++i) buffer_put_cstring(&m, resp[i]); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, &m); debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_RESPOND, &m); ret = buffer_get_int(&m); debug3("%s: pam_respond returned %d", __func__, ret); buffer_free(&m); return (ret); } void mm_sshpam_free_ctx(void *ctxtp) { Buffer m; debug3("%s", __func__); buffer_init(&m); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_FREE_CTX, &m); debug3("%s: waiting for MONITOR_ANS_PAM_FREE_CTX", __func__); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_FREE_CTX, &m); buffer_free(&m); } #endif /* USE_PAM */ /* Request process termination */ void mm_terminate(void) { Buffer m; buffer_init(&m); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, &m); buffer_free(&m); } int mm_ssh1_session_key(BIGNUM *num) { int rsafail; Buffer m; buffer_init(&m); buffer_put_bignum2(&m, num); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SESSKEY, &m); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SESSKEY, &m); rsafail = buffer_get_int(&m); buffer_get_bignum2(&m, num); buffer_free(&m); return (rsafail); } static void mm_chall_setup(char **name, char **infotxt, u_int *numprompts, char ***prompts, u_int **echo_on) { *name = xstrdup(""); *infotxt = xstrdup(""); *numprompts = 1; *prompts = xcalloc(*numprompts, sizeof(char *)); *echo_on = xcalloc(*numprompts, sizeof(u_int)); (*echo_on)[0] = 0; } int mm_bsdauth_query(void *ctx, char **name, char **infotxt, u_int *numprompts, char ***prompts, u_int **echo_on) { Buffer m; u_int success; char *challenge; debug3("%s: entering", __func__); buffer_init(&m); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, &m); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_BSDAUTHQUERY, &m); success = buffer_get_int(&m); if (success == 0) { debug3("%s: no challenge", __func__); buffer_free(&m); return (-1); } /* Get the challenge, and format the response */ challenge = buffer_get_string(&m, NULL); buffer_free(&m); mm_chall_setup(name, infotxt, numprompts, prompts, echo_on); (*prompts)[0] = challenge; debug3("%s: received challenge: %s", __func__, challenge); return (0); } int mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses) { Buffer m; int authok; debug3("%s: entering", __func__); if (numresponses != 1) return (-1); buffer_init(&m); buffer_put_cstring(&m, responses[0]); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, &m); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_BSDAUTHRESPOND, &m); authok = buffer_get_int(&m); buffer_free(&m); return ((authok == 0) ? -1 : 0); } #ifdef SKEY int mm_skey_query(void *ctx, char **name, char **infotxt, u_int *numprompts, char ***prompts, u_int **echo_on) { Buffer m; u_int success; char *challenge; debug3("%s: entering", __func__); buffer_init(&m); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYQUERY, &m); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SKEYQUERY, &m); success = buffer_get_int(&m); if (success == 0) { debug3("%s: no challenge", __func__); buffer_free(&m); return (-1); } /* Get the challenge, and format the response */ challenge = buffer_get_string(&m, NULL); buffer_free(&m); debug3("%s: received challenge: %s", __func__, challenge); mm_chall_setup(name, infotxt, numprompts, prompts, echo_on); xasprintf(*prompts, "%s%s", challenge, SKEY_PROMPT); free(challenge); return (0); } int mm_skey_respond(void *ctx, u_int numresponses, char **responses) { Buffer m; int authok; debug3("%s: entering", __func__); if (numresponses != 1) return (-1); buffer_init(&m); buffer_put_cstring(&m, responses[0]); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYRESPOND, &m); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SKEYRESPOND, &m); authok = buffer_get_int(&m); buffer_free(&m); return ((authok == 0) ? -1 : 0); } #endif /* SKEY */ void mm_ssh1_session_id(u_char session_id[16]) { Buffer m; int i; debug3("%s entering", __func__); buffer_init(&m); for (i = 0; i < 16; i++) buffer_put_char(&m, session_id[i]); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SESSID, &m); buffer_free(&m); } int mm_auth_rsa_key_allowed(struct passwd *pw, BIGNUM *client_n, Key **rkey) { Buffer m; Key *key; u_char *blob; u_int blen; int allowed = 0, have_forced = 0; debug3("%s entering", __func__); buffer_init(&m); buffer_put_bignum2(&m, client_n); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_RSAKEYALLOWED, &m); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_RSAKEYALLOWED, &m); allowed = buffer_get_int(&m); /* fake forced command */ auth_clear_options(); have_forced = buffer_get_int(&m); forced_command = have_forced ? xstrdup("true") : NULL; if (allowed && rkey != NULL) { blob = buffer_get_string(&m, &blen); if ((key = key_from_blob(blob, blen)) == NULL) fatal("%s: key_from_blob failed", __func__); *rkey = key; free(blob); } buffer_free(&m); return (allowed); } BIGNUM * mm_auth_rsa_generate_challenge(Key *key) { Buffer m; BIGNUM *challenge; u_char *blob; u_int blen; debug3("%s entering", __func__); if ((challenge = BN_new()) == NULL) fatal("%s: BN_new failed", __func__); key->type = KEY_RSA; /* XXX cheat for key_to_blob */ if (key_to_blob(key, &blob, &blen) == 0) fatal("%s: key_to_blob failed", __func__); key->type = KEY_RSA1; buffer_init(&m); buffer_put_string(&m, blob, blen); free(blob); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_RSACHALLENGE, &m); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_RSACHALLENGE, &m); buffer_get_bignum2(&m, challenge); buffer_free(&m); return (challenge); } int mm_auth_rsa_verify_response(Key *key, BIGNUM *p, u_char response[16]) { Buffer m; u_char *blob; u_int blen; int success = 0; debug3("%s entering", __func__); key->type = KEY_RSA; /* XXX cheat for key_to_blob */ if (key_to_blob(key, &blob, &blen) == 0) fatal("%s: key_to_blob failed", __func__); key->type = KEY_RSA1; buffer_init(&m); buffer_put_string(&m, blob, blen); buffer_put_string(&m, response, 16); free(blob); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_RSARESPONSE, &m); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_RSARESPONSE, &m); success = buffer_get_int(&m); buffer_free(&m); return (success); } #ifdef SSH_AUDIT_EVENTS void mm_audit_event(ssh_audit_event_t event) { Buffer m; debug3("%s entering", __func__); buffer_init(&m); buffer_put_int(&m, event); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_EVENT, &m); buffer_free(&m); } void mm_audit_run_command(const char *command) { Buffer m; debug3("%s entering command %s", __func__, command); buffer_init(&m); buffer_put_cstring(&m, command); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_COMMAND, &m); buffer_free(&m); } #endif /* SSH_AUDIT_EVENTS */ #ifdef GSSAPI OM_uint32 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid) { Buffer m; OM_uint32 major; /* Client doesn't get to see the context */ *ctx = NULL; buffer_init(&m); buffer_put_string(&m, goid->elements, goid->length); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, &m); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, &m); major = buffer_get_int(&m); buffer_free(&m); return (major); } OM_uint32 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in, gss_buffer_desc *out, OM_uint32 *flags) { Buffer m; OM_uint32 major; u_int len; buffer_init(&m); buffer_put_string(&m, in->value, in->length); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, &m); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, &m); major = buffer_get_int(&m); out->value = buffer_get_string(&m, &len); out->length = len; if (flags) *flags = buffer_get_int(&m); buffer_free(&m); return (major); } OM_uint32 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) { Buffer m; OM_uint32 major; buffer_init(&m); buffer_put_string(&m, gssbuf->value, gssbuf->length); buffer_put_string(&m, gssmic->value, gssmic->length); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, &m); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSCHECKMIC, &m); major = buffer_get_int(&m); buffer_free(&m); return(major); } int mm_ssh_gssapi_userok(char *user) { Buffer m; int authenticated = 0; buffer_init(&m); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, &m); mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUSEROK, &m); authenticated = buffer_get_int(&m); buffer_free(&m); debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not "); return (authenticated); } #endif /* GSSAPI */ Index: head/crypto/openssh/mux.c =================================================================== --- head/crypto/openssh/mux.c (revision 287142) +++ head/crypto/openssh/mux.c (revision 287143) @@ -1,2104 +1,2106 @@ /* $OpenBSD: mux.c,v 1.44 2013/07/12 00:19:58 djm Exp $ */ /* $FreeBSD$ */ /* * Copyright (c) 2002-2008 Damien Miller * * 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. */ /* ssh session multiplexing support */ /* * TODO: * - Better signalling from master to slave, especially passing of * error messages * - Better fall-back from mux slave error to new connection. * - ExitOnForwardingFailure * - Maybe extension mechanisms for multi-X11/multi-agent forwarding * - Support ~^Z in mux slaves. * - Inspect or control sessions in master. * - If we ever support the "signal" channel request, send signals on * sessions in master. */ #include "includes.h" __RCSID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef HAVE_PATHS_H #include #endif #ifdef HAVE_POLL_H #include #else # ifdef HAVE_SYS_POLL_H # include # endif #endif #ifdef HAVE_UTIL_H # include #endif #include "openbsd-compat/sys-queue.h" #include "xmalloc.h" #include "log.h" #include "ssh.h" #include "ssh2.h" #include "pathnames.h" #include "misc.h" #include "match.h" #include "buffer.h" #include "channels.h" #include "msg.h" #include "packet.h" #include "monitor_fdpass.h" #include "sshpty.h" #include "key.h" #include "readconf.h" #include "clientloop.h" /* from ssh.c */ extern int tty_flag; extern Options options; extern int stdin_null_flag; extern char *host; extern int subsystem_flag; extern Buffer command; extern volatile sig_atomic_t quit_pending; extern char *stdio_forward_host; extern int stdio_forward_port; /* Context for session open confirmation callback */ struct mux_session_confirm_ctx { u_int want_tty; u_int want_subsys; u_int want_x_fwd; u_int want_agent_fwd; Buffer cmd; char *term; struct termios tio; char **env; u_int rid; }; /* Context for global channel callback */ struct mux_channel_confirm_ctx { u_int cid; /* channel id */ u_int rid; /* request id */ int fid; /* forward id */ }; /* fd to control socket */ int muxserver_sock = -1; /* client request id */ u_int muxclient_request_id = 0; /* Multiplexing control command */ u_int muxclient_command = 0; /* Set when signalled. */ static volatile sig_atomic_t muxclient_terminate = 0; /* PID of multiplex server */ static u_int muxserver_pid = 0; static Channel *mux_listener_channel = NULL; struct mux_master_state { int hello_rcvd; }; /* mux protocol messages */ #define MUX_MSG_HELLO 0x00000001 #define MUX_C_NEW_SESSION 0x10000002 #define MUX_C_ALIVE_CHECK 0x10000004 #define MUX_C_TERMINATE 0x10000005 #define MUX_C_OPEN_FWD 0x10000006 #define MUX_C_CLOSE_FWD 0x10000007 #define MUX_C_NEW_STDIO_FWD 0x10000008 #define MUX_C_STOP_LISTENING 0x10000009 #define MUX_S_OK 0x80000001 #define MUX_S_PERMISSION_DENIED 0x80000002 #define MUX_S_FAILURE 0x80000003 #define MUX_S_EXIT_MESSAGE 0x80000004 #define MUX_S_ALIVE 0x80000005 #define MUX_S_SESSION_OPENED 0x80000006 #define MUX_S_REMOTE_PORT 0x80000007 #define MUX_S_TTY_ALLOC_FAIL 0x80000008 /* type codes for MUX_C_OPEN_FWD and MUX_C_CLOSE_FWD */ #define MUX_FWD_LOCAL 1 #define MUX_FWD_REMOTE 2 #define MUX_FWD_DYNAMIC 3 static void mux_session_confirm(int, int, void *); static int process_mux_master_hello(u_int, Channel *, Buffer *, Buffer *); static int process_mux_new_session(u_int, Channel *, Buffer *, Buffer *); static int process_mux_alive_check(u_int, Channel *, Buffer *, Buffer *); static int process_mux_terminate(u_int, Channel *, Buffer *, Buffer *); static int process_mux_open_fwd(u_int, Channel *, Buffer *, Buffer *); static int process_mux_close_fwd(u_int, Channel *, Buffer *, Buffer *); static int process_mux_stdio_fwd(u_int, Channel *, Buffer *, Buffer *); static int process_mux_stop_listening(u_int, Channel *, Buffer *, Buffer *); static const struct { u_int type; int (*handler)(u_int, Channel *, Buffer *, Buffer *); } mux_master_handlers[] = { { MUX_MSG_HELLO, process_mux_master_hello }, { MUX_C_NEW_SESSION, process_mux_new_session }, { MUX_C_ALIVE_CHECK, process_mux_alive_check }, { MUX_C_TERMINATE, process_mux_terminate }, { MUX_C_OPEN_FWD, process_mux_open_fwd }, { MUX_C_CLOSE_FWD, process_mux_close_fwd }, { MUX_C_NEW_STDIO_FWD, process_mux_stdio_fwd }, { MUX_C_STOP_LISTENING, process_mux_stop_listening }, { 0, NULL } }; /* Cleanup callback fired on closure of mux slave _session_ channel */ /* ARGSUSED */ static void mux_master_session_cleanup_cb(int cid, void *unused) { Channel *cc, *c = channel_by_id(cid); debug3("%s: entering for channel %d", __func__, cid); if (c == NULL) fatal("%s: channel_by_id(%i) == NULL", __func__, cid); if (c->ctl_chan != -1) { if ((cc = channel_by_id(c->ctl_chan)) == NULL) fatal("%s: channel %d missing control channel %d", __func__, c->self, c->ctl_chan); c->ctl_chan = -1; cc->remote_id = -1; chan_rcvd_oclose(cc); } channel_cancel_cleanup(c->self); } /* Cleanup callback fired on closure of mux slave _control_ channel */ /* ARGSUSED */ static void mux_master_control_cleanup_cb(int cid, void *unused) { Channel *sc, *c = channel_by_id(cid); debug3("%s: entering for channel %d", __func__, cid); if (c == NULL) fatal("%s: channel_by_id(%i) == NULL", __func__, cid); if (c->remote_id != -1) { if ((sc = channel_by_id(c->remote_id)) == NULL) fatal("%s: channel %d missing session channel %d", __func__, c->self, c->remote_id); c->remote_id = -1; sc->ctl_chan = -1; if (sc->type != SSH_CHANNEL_OPEN && sc->type != SSH_CHANNEL_OPENING) { debug2("%s: channel %d: not open", __func__, sc->self); chan_mark_dead(sc); } else { if (sc->istate == CHAN_INPUT_OPEN) chan_read_failed(sc); if (sc->ostate == CHAN_OUTPUT_OPEN) chan_write_failed(sc); } } channel_cancel_cleanup(c->self); } /* Check mux client environment variables before passing them to mux master. */ static int env_permitted(char *env) { int i, ret; char name[1024], *cp; if ((cp = strchr(env, '=')) == NULL || cp == env) return 0; ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env); if (ret <= 0 || (size_t)ret >= sizeof(name)) { error("env_permitted: name '%.100s...' too long", env); return 0; } for (i = 0; i < options.num_send_env; i++) if (match_pattern(name, options.send_env[i])) return 1; return 0; } /* Mux master protocol message handlers */ static int process_mux_master_hello(u_int rid, Channel *c, Buffer *m, Buffer *r) { u_int ver; struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx; if (state == NULL) fatal("%s: channel %d: c->mux_ctx == NULL", __func__, c->self); if (state->hello_rcvd) { error("%s: HELLO received twice", __func__); return -1; } if (buffer_get_int_ret(&ver, m) != 0) { malf: error("%s: malformed message", __func__); return -1; } if (ver != SSHMUX_VER) { error("Unsupported multiplexing protocol version %d " "(expected %d)", ver, SSHMUX_VER); return -1; } debug2("%s: channel %d slave version %u", __func__, c->self, ver); /* No extensions are presently defined */ while (buffer_len(m) > 0) { char *name = buffer_get_string_ret(m, NULL); char *value = buffer_get_string_ret(m, NULL); if (name == NULL || value == NULL) { free(name); free(value); goto malf; } debug2("Unrecognised slave extension \"%s\"", name); free(name); free(value); } state->hello_rcvd = 1; return 0; } static int process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r) { Channel *nc; struct mux_session_confirm_ctx *cctx; char *reserved, *cmd, *cp; u_int i, j, len, env_len, escape_char, window, packetmax; int new_fd[3]; /* Reply for SSHMUX_COMMAND_OPEN */ cctx = xcalloc(1, sizeof(*cctx)); cctx->term = NULL; cctx->rid = rid; cmd = reserved = NULL; cctx->env = NULL; env_len = 0; if ((reserved = buffer_get_string_ret(m, NULL)) == NULL || buffer_get_int_ret(&cctx->want_tty, m) != 0 || buffer_get_int_ret(&cctx->want_x_fwd, m) != 0 || buffer_get_int_ret(&cctx->want_agent_fwd, m) != 0 || buffer_get_int_ret(&cctx->want_subsys, m) != 0 || buffer_get_int_ret(&escape_char, m) != 0 || (cctx->term = buffer_get_string_ret(m, &len)) == NULL || (cmd = buffer_get_string_ret(m, &len)) == NULL) { malf: free(cmd); free(reserved); for (j = 0; j < env_len; j++) free(cctx->env[j]); free(cctx->env); free(cctx->term); free(cctx); error("%s: malformed message", __func__); return -1; } free(reserved); reserved = NULL; while (buffer_len(m) > 0) { #define MUX_MAX_ENV_VARS 4096 if ((cp = buffer_get_string_ret(m, &len)) == NULL) goto malf; if (!env_permitted(cp)) { free(cp); continue; } cctx->env = xrealloc(cctx->env, env_len + 2, sizeof(*cctx->env)); cctx->env[env_len++] = cp; cctx->env[env_len] = NULL; if (env_len > MUX_MAX_ENV_VARS) { error(">%d environment variables received, ignoring " "additional", MUX_MAX_ENV_VARS); break; } } debug2("%s: channel %d: request tty %d, X %d, agent %d, subsys %d, " "term \"%s\", cmd \"%s\", env %u", __func__, c->self, cctx->want_tty, cctx->want_x_fwd, cctx->want_agent_fwd, cctx->want_subsys, cctx->term, cmd, env_len); buffer_init(&cctx->cmd); buffer_append(&cctx->cmd, cmd, strlen(cmd)); free(cmd); cmd = NULL; /* Gather fds from client */ for(i = 0; i < 3; i++) { if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) { error("%s: failed to receive fd %d from slave", __func__, i); for (j = 0; j < i; j++) close(new_fd[j]); for (j = 0; j < env_len; j++) free(cctx->env[j]); free(cctx->env); free(cctx->term); buffer_free(&cctx->cmd); free(cctx); /* prepare reply */ buffer_put_int(r, MUX_S_FAILURE); buffer_put_int(r, rid); buffer_put_cstring(r, "did not receive file descriptors"); return -1; } } debug3("%s: got fds stdin %d, stdout %d, stderr %d", __func__, new_fd[0], new_fd[1], new_fd[2]); /* XXX support multiple child sessions in future */ if (c->remote_id != -1) { debug2("%s: session already open", __func__); /* prepare reply */ buffer_put_int(r, MUX_S_FAILURE); buffer_put_int(r, rid); buffer_put_cstring(r, "Multiple sessions not supported"); cleanup: close(new_fd[0]); close(new_fd[1]); close(new_fd[2]); free(cctx->term); if (env_len != 0) { for (i = 0; i < env_len; i++) free(cctx->env[i]); free(cctx->env); } buffer_free(&cctx->cmd); free(cctx); return 0; } if (options.control_master == SSHCTL_MASTER_ASK || options.control_master == SSHCTL_MASTER_AUTO_ASK) { if (!ask_permission("Allow shared connection to %s? ", host)) { debug2("%s: session refused by user", __func__); /* prepare reply */ buffer_put_int(r, MUX_S_PERMISSION_DENIED); buffer_put_int(r, rid); buffer_put_cstring(r, "Permission denied"); goto cleanup; } } /* Try to pick up ttymodes from client before it goes raw */ if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1) error("%s: tcgetattr: %s", __func__, strerror(errno)); /* enable nonblocking unless tty */ if (!isatty(new_fd[0])) set_nonblock(new_fd[0]); if (!isatty(new_fd[1])) set_nonblock(new_fd[1]); if (!isatty(new_fd[2])) set_nonblock(new_fd[2]); window = CHAN_SES_WINDOW_DEFAULT; packetmax = CHAN_SES_PACKET_DEFAULT; if (cctx->want_tty) { window >>= 1; packetmax >>= 1; } nc = channel_new("session", SSH_CHANNEL_OPENING, new_fd[0], new_fd[1], new_fd[2], window, packetmax, CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0); nc->ctl_chan = c->self; /* link session -> control channel */ c->remote_id = nc->self; /* link control -> session channel */ if (cctx->want_tty && escape_char != 0xffffffff) { channel_register_filter(nc->self, client_simple_escape_filter, NULL, client_filter_cleanup, client_new_escape_filter_ctx((int)escape_char)); } debug2("%s: channel_new: %d linked to control channel %d", __func__, nc->self, nc->ctl_chan); channel_send_open(nc->self); channel_register_open_confirm(nc->self, mux_session_confirm, cctx); c->mux_pause = 1; /* stop handling messages until open_confirm done */ channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1); /* reply is deferred, sent by mux_session_confirm */ return 0; } static int process_mux_alive_check(u_int rid, Channel *c, Buffer *m, Buffer *r) { debug2("%s: channel %d: alive check", __func__, c->self); /* prepare reply */ buffer_put_int(r, MUX_S_ALIVE); buffer_put_int(r, rid); buffer_put_int(r, (u_int)getpid()); return 0; } static int process_mux_terminate(u_int rid, Channel *c, Buffer *m, Buffer *r) { debug2("%s: channel %d: terminate request", __func__, c->self); if (options.control_master == SSHCTL_MASTER_ASK || options.control_master == SSHCTL_MASTER_AUTO_ASK) { if (!ask_permission("Terminate shared connection to %s? ", host)) { debug2("%s: termination refused by user", __func__); buffer_put_int(r, MUX_S_PERMISSION_DENIED); buffer_put_int(r, rid); buffer_put_cstring(r, "Permission denied"); return 0; } } quit_pending = 1; buffer_put_int(r, MUX_S_OK); buffer_put_int(r, rid); /* XXX exit happens too soon - message never makes it to client */ return 0; } static char * format_forward(u_int ftype, Forward *fwd) { char *ret; switch (ftype) { case MUX_FWD_LOCAL: xasprintf(&ret, "local forward %.200s:%d -> %.200s:%d", (fwd->listen_host == NULL) ? (options.gateway_ports ? "*" : "LOCALHOST") : fwd->listen_host, fwd->listen_port, fwd->connect_host, fwd->connect_port); break; case MUX_FWD_DYNAMIC: xasprintf(&ret, "dynamic forward %.200s:%d -> *", (fwd->listen_host == NULL) ? (options.gateway_ports ? "*" : "LOCALHOST") : fwd->listen_host, fwd->listen_port); break; case MUX_FWD_REMOTE: xasprintf(&ret, "remote forward %.200s:%d -> %.200s:%d", (fwd->listen_host == NULL) ? "LOCALHOST" : fwd->listen_host, fwd->listen_port, fwd->connect_host, fwd->connect_port); break; default: fatal("%s: unknown forward type %u", __func__, ftype); } return ret; } static int compare_host(const char *a, const char *b) { if (a == NULL && b == NULL) return 1; if (a == NULL || b == NULL) return 0; return strcmp(a, b) == 0; } static int compare_forward(Forward *a, Forward *b) { if (!compare_host(a->listen_host, b->listen_host)) return 0; if (a->listen_port != b->listen_port) return 0; if (!compare_host(a->connect_host, b->connect_host)) return 0; if (a->connect_port != b->connect_port) return 0; return 1; } static void mux_confirm_remote_forward(int type, u_int32_t seq, void *ctxt) { struct mux_channel_confirm_ctx *fctx = ctxt; char *failmsg = NULL; Forward *rfwd; Channel *c; Buffer out; if ((c = channel_by_id(fctx->cid)) == NULL) { /* no channel for reply */ error("%s: unknown channel", __func__); return; } buffer_init(&out); if (fctx->fid >= options.num_remote_forwards) { xasprintf(&failmsg, "unknown forwarding id %d", fctx->fid); goto fail; } rfwd = &options.remote_forwards[fctx->fid]; debug("%s: %s for: listen %d, connect %s:%d", __func__, type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", rfwd->listen_port, rfwd->connect_host, rfwd->connect_port); if (type == SSH2_MSG_REQUEST_SUCCESS) { if (rfwd->listen_port == 0) { rfwd->allocated_port = packet_get_int(); logit("Allocated port %u for mux remote forward" " to %s:%d", rfwd->allocated_port, rfwd->connect_host, rfwd->connect_port); buffer_put_int(&out, MUX_S_REMOTE_PORT); buffer_put_int(&out, fctx->rid); buffer_put_int(&out, rfwd->allocated_port); channel_update_permitted_opens(rfwd->handle, rfwd->allocated_port); } else { buffer_put_int(&out, MUX_S_OK); buffer_put_int(&out, fctx->rid); } goto out; } else { if (rfwd->listen_port == 0) channel_update_permitted_opens(rfwd->handle, -1); xasprintf(&failmsg, "remote port forwarding failed for " "listen port %d", rfwd->listen_port); } fail: error("%s: %s", __func__, failmsg); buffer_put_int(&out, MUX_S_FAILURE); buffer_put_int(&out, fctx->rid); buffer_put_cstring(&out, failmsg); free(failmsg); out: buffer_put_string(&c->output, buffer_ptr(&out), buffer_len(&out)); buffer_free(&out); if (c->mux_pause <= 0) fatal("%s: mux_pause %d", __func__, c->mux_pause); c->mux_pause = 0; /* start processing messages again */ } static int process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) { Forward fwd; char *fwd_desc = NULL; u_int ftype; u_int lport, cport; int i, ret = 0, freefwd = 1; - fwd.listen_host = fwd.connect_host = NULL; + memset(&fwd, 0, sizeof(fwd)); + if (buffer_get_int_ret(&ftype, m) != 0 || (fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL || buffer_get_int_ret(&lport, m) != 0 || (fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL || buffer_get_int_ret(&cport, m) != 0 || lport > 65535 || cport > 65535) { error("%s: malformed message", __func__); ret = -1; goto out; } fwd.listen_port = lport; fwd.connect_port = cport; if (*fwd.listen_host == '\0') { free(fwd.listen_host); fwd.listen_host = NULL; } if (*fwd.connect_host == '\0') { free(fwd.connect_host); fwd.connect_host = NULL; } debug2("%s: channel %d: request %s", __func__, c->self, (fwd_desc = format_forward(ftype, &fwd))); if (ftype != MUX_FWD_LOCAL && ftype != MUX_FWD_REMOTE && ftype != MUX_FWD_DYNAMIC) { logit("%s: invalid forwarding type %u", __func__, ftype); invalid: free(fwd.listen_host); free(fwd.connect_host); buffer_put_int(r, MUX_S_FAILURE); buffer_put_int(r, rid); buffer_put_cstring(r, "Invalid forwarding request"); return 0; } if (fwd.listen_port >= 65536) { logit("%s: invalid listen port %u", __func__, fwd.listen_port); goto invalid; } if (fwd.connect_port >= 65536 || (ftype != MUX_FWD_DYNAMIC && ftype != MUX_FWD_REMOTE && fwd.connect_port == 0)) { logit("%s: invalid connect port %u", __func__, fwd.connect_port); goto invalid; } if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL) { logit("%s: missing connect host", __func__); goto invalid; } /* Skip forwards that have already been requested */ switch (ftype) { case MUX_FWD_LOCAL: case MUX_FWD_DYNAMIC: for (i = 0; i < options.num_local_forwards; i++) { if (compare_forward(&fwd, options.local_forwards + i)) { exists: debug2("%s: found existing forwarding", __func__); buffer_put_int(r, MUX_S_OK); buffer_put_int(r, rid); goto out; } } break; case MUX_FWD_REMOTE: for (i = 0; i < options.num_remote_forwards; i++) { if (compare_forward(&fwd, options.remote_forwards + i)) { if (fwd.listen_port != 0) goto exists; debug2("%s: found allocated port", __func__); buffer_put_int(r, MUX_S_REMOTE_PORT); buffer_put_int(r, rid); buffer_put_int(r, options.remote_forwards[i].allocated_port); goto out; } } break; } if (options.control_master == SSHCTL_MASTER_ASK || options.control_master == SSHCTL_MASTER_AUTO_ASK) { if (!ask_permission("Open %s on %s?", fwd_desc, host)) { debug2("%s: forwarding refused by user", __func__); buffer_put_int(r, MUX_S_PERMISSION_DENIED); buffer_put_int(r, rid); buffer_put_cstring(r, "Permission denied"); goto out; } } if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) { if (!channel_setup_local_fwd_listener(fwd.listen_host, fwd.listen_port, fwd.connect_host, fwd.connect_port, options.gateway_ports)) { fail: logit("slave-requested %s failed", fwd_desc); buffer_put_int(r, MUX_S_FAILURE); buffer_put_int(r, rid); buffer_put_cstring(r, "Port forwarding failed"); goto out; } add_local_forward(&options, &fwd); freefwd = 0; } else { struct mux_channel_confirm_ctx *fctx; fwd.handle = channel_request_remote_forwarding(fwd.listen_host, fwd.listen_port, fwd.connect_host, fwd.connect_port); if (fwd.handle < 0) goto fail; add_remote_forward(&options, &fwd); fctx = xcalloc(1, sizeof(*fctx)); fctx->cid = c->self; fctx->rid = rid; fctx->fid = options.num_remote_forwards - 1; client_register_global_confirm(mux_confirm_remote_forward, fctx); freefwd = 0; c->mux_pause = 1; /* wait for mux_confirm_remote_forward */ /* delayed reply in mux_confirm_remote_forward */ goto out; } buffer_put_int(r, MUX_S_OK); buffer_put_int(r, rid); out: free(fwd_desc); if (freefwd) { free(fwd.listen_host); free(fwd.connect_host); } return ret; } static int process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) { Forward fwd, *found_fwd; char *fwd_desc = NULL; const char *error_reason = NULL; u_int ftype; int i, listen_port, ret = 0; u_int lport, cport; - fwd.listen_host = fwd.connect_host = NULL; + memset(&fwd, 0, sizeof(fwd)); + if (buffer_get_int_ret(&ftype, m) != 0 || (fwd.listen_host = buffer_get_string_ret(m, NULL)) == NULL || buffer_get_int_ret(&lport, m) != 0 || (fwd.connect_host = buffer_get_string_ret(m, NULL)) == NULL || buffer_get_int_ret(&cport, m) != 0 || lport > 65535 || cport > 65535) { error("%s: malformed message", __func__); ret = -1; goto out; } fwd.listen_port = lport; fwd.connect_port = cport; if (*fwd.listen_host == '\0') { free(fwd.listen_host); fwd.listen_host = NULL; } if (*fwd.connect_host == '\0') { free(fwd.connect_host); fwd.connect_host = NULL; } debug2("%s: channel %d: request cancel %s", __func__, c->self, (fwd_desc = format_forward(ftype, &fwd))); /* make sure this has been requested */ found_fwd = NULL; switch (ftype) { case MUX_FWD_LOCAL: case MUX_FWD_DYNAMIC: for (i = 0; i < options.num_local_forwards; i++) { if (compare_forward(&fwd, options.local_forwards + i)) { found_fwd = options.local_forwards + i; break; } } break; case MUX_FWD_REMOTE: for (i = 0; i < options.num_remote_forwards; i++) { if (compare_forward(&fwd, options.remote_forwards + i)) { found_fwd = options.remote_forwards + i; break; } } break; } if (found_fwd == NULL) error_reason = "port not forwarded"; else if (ftype == MUX_FWD_REMOTE) { /* * This shouldn't fail unless we confused the host/port * between options.remote_forwards and permitted_opens. * However, for dynamic allocated listen ports we need * to lookup the actual listen port. */ listen_port = (fwd.listen_port == 0) ? found_fwd->allocated_port : fwd.listen_port; if (channel_request_rforward_cancel(fwd.listen_host, listen_port) == -1) error_reason = "port not in permitted opens"; } else { /* local and dynamic forwards */ /* Ditto */ if (channel_cancel_lport_listener(fwd.listen_host, fwd.listen_port, fwd.connect_port, options.gateway_ports) == -1) error_reason = "port not found"; } if (error_reason == NULL) { buffer_put_int(r, MUX_S_OK); buffer_put_int(r, rid); free(found_fwd->listen_host); free(found_fwd->connect_host); found_fwd->listen_host = found_fwd->connect_host = NULL; found_fwd->listen_port = found_fwd->connect_port = 0; } else { buffer_put_int(r, MUX_S_FAILURE); buffer_put_int(r, rid); buffer_put_cstring(r, error_reason); } out: free(fwd_desc); free(fwd.listen_host); free(fwd.connect_host); return ret; } static int process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) { Channel *nc; char *reserved, *chost; u_int cport, i, j; int new_fd[2]; chost = reserved = NULL; if ((reserved = buffer_get_string_ret(m, NULL)) == NULL || (chost = buffer_get_string_ret(m, NULL)) == NULL || buffer_get_int_ret(&cport, m) != 0) { free(reserved); free(chost); error("%s: malformed message", __func__); return -1; } free(reserved); debug2("%s: channel %d: request stdio fwd to %s:%u", __func__, c->self, chost, cport); /* Gather fds from client */ for(i = 0; i < 2; i++) { if ((new_fd[i] = mm_receive_fd(c->sock)) == -1) { error("%s: failed to receive fd %d from slave", __func__, i); for (j = 0; j < i; j++) close(new_fd[j]); free(chost); /* prepare reply */ buffer_put_int(r, MUX_S_FAILURE); buffer_put_int(r, rid); buffer_put_cstring(r, "did not receive file descriptors"); return -1; } } debug3("%s: got fds stdin %d, stdout %d", __func__, new_fd[0], new_fd[1]); /* XXX support multiple child sessions in future */ if (c->remote_id != -1) { debug2("%s: session already open", __func__); /* prepare reply */ buffer_put_int(r, MUX_S_FAILURE); buffer_put_int(r, rid); buffer_put_cstring(r, "Multiple sessions not supported"); cleanup: close(new_fd[0]); close(new_fd[1]); free(chost); return 0; } if (options.control_master == SSHCTL_MASTER_ASK || options.control_master == SSHCTL_MASTER_AUTO_ASK) { if (!ask_permission("Allow forward to %s:%u? ", chost, cport)) { debug2("%s: stdio fwd refused by user", __func__); /* prepare reply */ buffer_put_int(r, MUX_S_PERMISSION_DENIED); buffer_put_int(r, rid); buffer_put_cstring(r, "Permission denied"); goto cleanup; } } /* enable nonblocking unless tty */ if (!isatty(new_fd[0])) set_nonblock(new_fd[0]); if (!isatty(new_fd[1])) set_nonblock(new_fd[1]); nc = channel_connect_stdio_fwd(chost, cport, new_fd[0], new_fd[1]); nc->ctl_chan = c->self; /* link session -> control channel */ c->remote_id = nc->self; /* link control -> session channel */ debug2("%s: channel_new: %d linked to control channel %d", __func__, nc->self, nc->ctl_chan); channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1); /* prepare reply */ /* XXX defer until channel confirmed */ buffer_put_int(r, MUX_S_SESSION_OPENED); buffer_put_int(r, rid); buffer_put_int(r, nc->self); return 0; } static int process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r) { debug("%s: channel %d: stop listening", __func__, c->self); if (options.control_master == SSHCTL_MASTER_ASK || options.control_master == SSHCTL_MASTER_AUTO_ASK) { if (!ask_permission("Disable further multiplexing on shared " "connection to %s? ", host)) { debug2("%s: stop listen refused by user", __func__); buffer_put_int(r, MUX_S_PERMISSION_DENIED); buffer_put_int(r, rid); buffer_put_cstring(r, "Permission denied"); return 0; } } if (mux_listener_channel != NULL) { channel_free(mux_listener_channel); client_stop_mux(); free(options.control_path); options.control_path = NULL; mux_listener_channel = NULL; muxserver_sock = -1; } /* prepare reply */ buffer_put_int(r, MUX_S_OK); buffer_put_int(r, rid); return 0; } /* Channel callbacks fired on read/write from mux slave fd */ static int mux_master_read_cb(Channel *c) { struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx; Buffer in, out; void *ptr; u_int type, rid, have, i; int ret = -1; /* Setup ctx and */ if (c->mux_ctx == NULL) { state = xcalloc(1, sizeof(*state)); c->mux_ctx = state; channel_register_cleanup(c->self, mux_master_control_cleanup_cb, 0); /* Send hello */ buffer_init(&out); buffer_put_int(&out, MUX_MSG_HELLO); buffer_put_int(&out, SSHMUX_VER); /* no extensions */ buffer_put_string(&c->output, buffer_ptr(&out), buffer_len(&out)); buffer_free(&out); debug3("%s: channel %d: hello sent", __func__, c->self); return 0; } buffer_init(&in); buffer_init(&out); /* Channel code ensures that we receive whole packets */ if ((ptr = buffer_get_string_ptr_ret(&c->input, &have)) == NULL) { malf: error("%s: malformed message", __func__); goto out; } buffer_append(&in, ptr, have); if (buffer_get_int_ret(&type, &in) != 0) goto malf; debug3("%s: channel %d packet type 0x%08x len %u", __func__, c->self, type, buffer_len(&in)); if (type == MUX_MSG_HELLO) rid = 0; else { if (!state->hello_rcvd) { error("%s: expected MUX_MSG_HELLO(0x%08x), " "received 0x%08x", __func__, MUX_MSG_HELLO, type); goto out; } if (buffer_get_int_ret(&rid, &in) != 0) goto malf; } for (i = 0; mux_master_handlers[i].handler != NULL; i++) { if (type == mux_master_handlers[i].type) { ret = mux_master_handlers[i].handler(rid, c, &in, &out); break; } } if (mux_master_handlers[i].handler == NULL) { error("%s: unsupported mux message 0x%08x", __func__, type); buffer_put_int(&out, MUX_S_FAILURE); buffer_put_int(&out, rid); buffer_put_cstring(&out, "unsupported request"); ret = 0; } /* Enqueue reply packet */ if (buffer_len(&out) != 0) { buffer_put_string(&c->output, buffer_ptr(&out), buffer_len(&out)); } out: buffer_free(&in); buffer_free(&out); return ret; } void mux_exit_message(Channel *c, int exitval) { Buffer m; Channel *mux_chan; debug3("%s: channel %d: exit message, exitval %d", __func__, c->self, exitval); if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL) fatal("%s: channel %d missing mux channel %d", __func__, c->self, c->ctl_chan); /* Append exit message packet to control socket output queue */ buffer_init(&m); buffer_put_int(&m, MUX_S_EXIT_MESSAGE); buffer_put_int(&m, c->self); buffer_put_int(&m, exitval); buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m)); buffer_free(&m); } void mux_tty_alloc_failed(Channel *c) { Buffer m; Channel *mux_chan; debug3("%s: channel %d: TTY alloc failed", __func__, c->self); if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL) fatal("%s: channel %d missing mux channel %d", __func__, c->self, c->ctl_chan); /* Append exit message packet to control socket output queue */ buffer_init(&m); buffer_put_int(&m, MUX_S_TTY_ALLOC_FAIL); buffer_put_int(&m, c->self); buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m)); buffer_free(&m); } /* Prepare a mux master to listen on a Unix domain socket. */ void muxserver_listen(void) { struct sockaddr_un addr; socklen_t sun_len; mode_t old_umask; char *orig_control_path = options.control_path; char rbuf[16+1]; u_int i, r; if (options.control_path == NULL || options.control_master == SSHCTL_MASTER_NO) return; debug("setting up multiplex master socket"); /* * Use a temporary path before listen so we can pseudo-atomically * establish the listening socket in its final location to avoid * other processes racing in between bind() and listen() and hitting * an unready socket. */ for (i = 0; i < sizeof(rbuf) - 1; i++) { r = arc4random_uniform(26+26+10); rbuf[i] = (r < 26) ? 'a' + r : (r < 26*2) ? 'A' + r - 26 : '0' + r - 26 - 26; } rbuf[sizeof(rbuf) - 1] = '\0'; options.control_path = NULL; xasprintf(&options.control_path, "%s.%s", orig_control_path, rbuf); debug3("%s: temporary control path %s", __func__, options.control_path); memset(&addr, '\0', sizeof(addr)); addr.sun_family = AF_UNIX; sun_len = offsetof(struct sockaddr_un, sun_path) + strlen(options.control_path) + 1; if (strlcpy(addr.sun_path, options.control_path, sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) { error("ControlPath \"%s\" too long for Unix domain socket", options.control_path); goto disable_mux_master; } if ((muxserver_sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) fatal("%s socket(): %s", __func__, strerror(errno)); old_umask = umask(0177); if (bind(muxserver_sock, (struct sockaddr *)&addr, sun_len) == -1) { if (errno == EINVAL || errno == EADDRINUSE) { error("ControlSocket %s already exists, " "disabling multiplexing", options.control_path); disable_mux_master: if (muxserver_sock != -1) { close(muxserver_sock); muxserver_sock = -1; } free(orig_control_path); free(options.control_path); options.control_path = NULL; options.control_master = SSHCTL_MASTER_NO; return; } else fatal("%s bind(): %s", __func__, strerror(errno)); } umask(old_umask); if (listen(muxserver_sock, 64) == -1) fatal("%s listen(): %s", __func__, strerror(errno)); /* Now atomically "move" the mux socket into position */ if (link(options.control_path, orig_control_path) != 0) { if (errno != EEXIST) { fatal("%s: link mux listener %s => %s: %s", __func__, options.control_path, orig_control_path, strerror(errno)); } error("ControlSocket %s already exists, disabling multiplexing", orig_control_path); unlink(options.control_path); goto disable_mux_master; } unlink(options.control_path); free(options.control_path); options.control_path = orig_control_path; set_nonblock(muxserver_sock); mux_listener_channel = channel_new("mux listener", SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, options.control_path, 1); mux_listener_channel->mux_rcb = mux_master_read_cb; debug3("%s: mux listener channel %d fd %d", __func__, mux_listener_channel->self, mux_listener_channel->sock); } /* Callback on open confirmation in mux master for a mux client session. */ static void mux_session_confirm(int id, int success, void *arg) { struct mux_session_confirm_ctx *cctx = arg; const char *display; Channel *c, *cc; int i; Buffer reply; if (cctx == NULL) fatal("%s: cctx == NULL", __func__); if ((c = channel_by_id(id)) == NULL) fatal("%s: no channel for id %d", __func__, id); if ((cc = channel_by_id(c->ctl_chan)) == NULL) fatal("%s: channel %d lacks control channel %d", __func__, id, c->ctl_chan); if (!success) { debug3("%s: sending failure reply", __func__); /* prepare reply */ buffer_init(&reply); buffer_put_int(&reply, MUX_S_FAILURE); buffer_put_int(&reply, cctx->rid); buffer_put_cstring(&reply, "Session open refused by peer"); goto done; } display = getenv("DISPLAY"); if (cctx->want_x_fwd && options.forward_x11 && display != NULL) { char *proto, *data; /* Get reasonable local authentication information. */ client_x11_get_proto(display, options.xauth_location, options.forward_x11_trusted, options.forward_x11_timeout, &proto, &data); /* Request forwarding with authentication spoofing. */ debug("Requesting X11 forwarding with authentication " "spoofing."); x11_request_forwarding_with_spoofing(id, display, proto, data, 1); client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN); /* XXX exit_on_forward_failure */ } if (cctx->want_agent_fwd && options.forward_agent) { debug("Requesting authentication agent forwarding."); channel_request_start(id, "auth-agent-req@openssh.com", 0); packet_send(); } client_session2_setup(id, cctx->want_tty, cctx->want_subsys, cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env); debug3("%s: sending success reply", __func__); /* prepare reply */ buffer_init(&reply); buffer_put_int(&reply, MUX_S_SESSION_OPENED); buffer_put_int(&reply, cctx->rid); buffer_put_int(&reply, c->self); done: /* Send reply */ buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply)); buffer_free(&reply); if (cc->mux_pause <= 0) fatal("%s: mux_pause %d", __func__, cc->mux_pause); cc->mux_pause = 0; /* start processing messages again */ c->open_confirm_ctx = NULL; buffer_free(&cctx->cmd); free(cctx->term); if (cctx->env != NULL) { for (i = 0; cctx->env[i] != NULL; i++) free(cctx->env[i]); free(cctx->env); } free(cctx); } /* ** Multiplexing client support */ /* Exit signal handler */ static void control_client_sighandler(int signo) { muxclient_terminate = signo; } /* * Relay signal handler - used to pass some signals from mux client to * mux master. */ static void control_client_sigrelay(int signo) { int save_errno = errno; if (muxserver_pid > 1) kill(muxserver_pid, signo); errno = save_errno; } static int mux_client_read(int fd, Buffer *b, u_int need) { u_int have; ssize_t len; u_char *p; struct pollfd pfd; pfd.fd = fd; pfd.events = POLLIN; p = buffer_append_space(b, need); for (have = 0; have < need; ) { if (muxclient_terminate) { errno = EINTR; return -1; } len = read(fd, p + have, need - have); if (len < 0) { switch (errno) { #if defined(EWOULDBLOCK) && (EWOULDBLOCK != EAGAIN) case EWOULDBLOCK: #endif case EAGAIN: (void)poll(&pfd, 1, -1); /* FALLTHROUGH */ case EINTR: continue; default: return -1; } } if (len == 0) { errno = EPIPE; return -1; } have += (u_int)len; } return 0; } static int mux_client_write_packet(int fd, Buffer *m) { Buffer queue; u_int have, need; int oerrno, len; u_char *ptr; struct pollfd pfd; pfd.fd = fd; pfd.events = POLLOUT; buffer_init(&queue); buffer_put_string(&queue, buffer_ptr(m), buffer_len(m)); need = buffer_len(&queue); ptr = buffer_ptr(&queue); for (have = 0; have < need; ) { if (muxclient_terminate) { buffer_free(&queue); errno = EINTR; return -1; } len = write(fd, ptr + have, need - have); if (len < 0) { switch (errno) { #if defined(EWOULDBLOCK) && (EWOULDBLOCK != EAGAIN) case EWOULDBLOCK: #endif case EAGAIN: (void)poll(&pfd, 1, -1); /* FALLTHROUGH */ case EINTR: continue; default: oerrno = errno; buffer_free(&queue); errno = oerrno; return -1; } } if (len == 0) { buffer_free(&queue); errno = EPIPE; return -1; } have += (u_int)len; } buffer_free(&queue); return 0; } static int mux_client_read_packet(int fd, Buffer *m) { Buffer queue; u_int need, have; void *ptr; int oerrno; buffer_init(&queue); if (mux_client_read(fd, &queue, 4) != 0) { if ((oerrno = errno) == EPIPE) debug3("%s: read header failed: %s", __func__, strerror(errno)); buffer_free(&queue); errno = oerrno; return -1; } need = get_u32(buffer_ptr(&queue)); if (mux_client_read(fd, &queue, need) != 0) { oerrno = errno; debug3("%s: read body failed: %s", __func__, strerror(errno)); buffer_free(&queue); errno = oerrno; return -1; } ptr = buffer_get_string_ptr(&queue, &have); buffer_append(m, ptr, have); buffer_free(&queue); return 0; } static int mux_client_hello_exchange(int fd) { Buffer m; u_int type, ver; buffer_init(&m); buffer_put_int(&m, MUX_MSG_HELLO); buffer_put_int(&m, SSHMUX_VER); /* no extensions */ if (mux_client_write_packet(fd, &m) != 0) fatal("%s: write packet: %s", __func__, strerror(errno)); buffer_clear(&m); /* Read their HELLO */ if (mux_client_read_packet(fd, &m) != 0) { buffer_free(&m); return -1; } type = buffer_get_int(&m); if (type != MUX_MSG_HELLO) fatal("%s: expected HELLO (%u) received %u", __func__, MUX_MSG_HELLO, type); ver = buffer_get_int(&m); if (ver != SSHMUX_VER) fatal("Unsupported multiplexing protocol version %d " "(expected %d)", ver, SSHMUX_VER); debug2("%s: master version %u", __func__, ver); /* No extensions are presently defined */ while (buffer_len(&m) > 0) { char *name = buffer_get_string(&m, NULL); char *value = buffer_get_string(&m, NULL); debug2("Unrecognised master extension \"%s\"", name); free(name); free(value); } buffer_free(&m); return 0; } static u_int mux_client_request_alive(int fd) { Buffer m; char *e; u_int pid, type, rid; debug3("%s: entering", __func__); buffer_init(&m); buffer_put_int(&m, MUX_C_ALIVE_CHECK); buffer_put_int(&m, muxclient_request_id); if (mux_client_write_packet(fd, &m) != 0) fatal("%s: write packet: %s", __func__, strerror(errno)); buffer_clear(&m); /* Read their reply */ if (mux_client_read_packet(fd, &m) != 0) { buffer_free(&m); return 0; } type = buffer_get_int(&m); if (type != MUX_S_ALIVE) { e = buffer_get_string(&m, NULL); fatal("%s: master returned error: %s", __func__, e); } if ((rid = buffer_get_int(&m)) != muxclient_request_id) fatal("%s: out of sequence reply: my id %u theirs %u", __func__, muxclient_request_id, rid); pid = buffer_get_int(&m); buffer_free(&m); debug3("%s: done pid = %u", __func__, pid); muxclient_request_id++; return pid; } static void mux_client_request_terminate(int fd) { Buffer m; char *e; u_int type, rid; debug3("%s: entering", __func__); buffer_init(&m); buffer_put_int(&m, MUX_C_TERMINATE); buffer_put_int(&m, muxclient_request_id); if (mux_client_write_packet(fd, &m) != 0) fatal("%s: write packet: %s", __func__, strerror(errno)); buffer_clear(&m); /* Read their reply */ if (mux_client_read_packet(fd, &m) != 0) { /* Remote end exited already */ if (errno == EPIPE) { buffer_free(&m); return; } fatal("%s: read from master failed: %s", __func__, strerror(errno)); } type = buffer_get_int(&m); if ((rid = buffer_get_int(&m)) != muxclient_request_id) fatal("%s: out of sequence reply: my id %u theirs %u", __func__, muxclient_request_id, rid); switch (type) { case MUX_S_OK: break; case MUX_S_PERMISSION_DENIED: e = buffer_get_string(&m, NULL); fatal("Master refused termination request: %s", e); case MUX_S_FAILURE: e = buffer_get_string(&m, NULL); fatal("%s: termination request failed: %s", __func__, e); default: fatal("%s: unexpected response from master 0x%08x", __func__, type); } buffer_free(&m); muxclient_request_id++; } static int mux_client_forward(int fd, int cancel_flag, u_int ftype, Forward *fwd) { Buffer m; char *e, *fwd_desc; u_int type, rid; fwd_desc = format_forward(ftype, fwd); debug("Requesting %s %s", cancel_flag ? "cancellation of" : "forwarding of", fwd_desc); free(fwd_desc); buffer_init(&m); buffer_put_int(&m, cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD); buffer_put_int(&m, muxclient_request_id); buffer_put_int(&m, ftype); buffer_put_cstring(&m, fwd->listen_host == NULL ? "" : fwd->listen_host); buffer_put_int(&m, fwd->listen_port); buffer_put_cstring(&m, fwd->connect_host == NULL ? "" : fwd->connect_host); buffer_put_int(&m, fwd->connect_port); if (mux_client_write_packet(fd, &m) != 0) fatal("%s: write packet: %s", __func__, strerror(errno)); buffer_clear(&m); /* Read their reply */ if (mux_client_read_packet(fd, &m) != 0) { buffer_free(&m); return -1; } type = buffer_get_int(&m); if ((rid = buffer_get_int(&m)) != muxclient_request_id) fatal("%s: out of sequence reply: my id %u theirs %u", __func__, muxclient_request_id, rid); switch (type) { case MUX_S_OK: break; case MUX_S_REMOTE_PORT: if (cancel_flag) fatal("%s: got MUX_S_REMOTE_PORT for cancel", __func__); fwd->allocated_port = buffer_get_int(&m); logit("Allocated port %u for remote forward to %s:%d", fwd->allocated_port, fwd->connect_host ? fwd->connect_host : "", fwd->connect_port); if (muxclient_command == SSHMUX_COMMAND_FORWARD) fprintf(stdout, "%u\n", fwd->allocated_port); break; case MUX_S_PERMISSION_DENIED: e = buffer_get_string(&m, NULL); buffer_free(&m); error("Master refused forwarding request: %s", e); return -1; case MUX_S_FAILURE: e = buffer_get_string(&m, NULL); buffer_free(&m); error("%s: forwarding request failed: %s", __func__, e); return -1; default: fatal("%s: unexpected response from master 0x%08x", __func__, type); } buffer_free(&m); muxclient_request_id++; return 0; } static int mux_client_forwards(int fd, int cancel_flag) { int i, ret = 0; debug3("%s: %s forwardings: %d local, %d remote", __func__, cancel_flag ? "cancel" : "request", options.num_local_forwards, options.num_remote_forwards); /* XXX ExitOnForwardingFailure */ for (i = 0; i < options.num_local_forwards; i++) { if (mux_client_forward(fd, cancel_flag, options.local_forwards[i].connect_port == 0 ? MUX_FWD_DYNAMIC : MUX_FWD_LOCAL, options.local_forwards + i) != 0) ret = -1; } for (i = 0; i < options.num_remote_forwards; i++) { if (mux_client_forward(fd, cancel_flag, MUX_FWD_REMOTE, options.remote_forwards + i) != 0) ret = -1; } return ret; } static int mux_client_request_session(int fd) { Buffer m; char *e, *term; u_int i, rid, sid, esid, exitval, type, exitval_seen; extern char **environ; int devnull, rawmode; debug3("%s: entering", __func__); if ((muxserver_pid = mux_client_request_alive(fd)) == 0) { error("%s: master alive request failed", __func__); return -1; } signal(SIGPIPE, SIG_IGN); if (stdin_null_flag) { if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1) fatal("open(/dev/null): %s", strerror(errno)); if (dup2(devnull, STDIN_FILENO) == -1) fatal("dup2: %s", strerror(errno)); if (devnull > STDERR_FILENO) close(devnull); } term = getenv("TERM"); buffer_init(&m); buffer_put_int(&m, MUX_C_NEW_SESSION); buffer_put_int(&m, muxclient_request_id); buffer_put_cstring(&m, ""); /* reserved */ buffer_put_int(&m, tty_flag); buffer_put_int(&m, options.forward_x11); buffer_put_int(&m, options.forward_agent); buffer_put_int(&m, subsystem_flag); buffer_put_int(&m, options.escape_char == SSH_ESCAPECHAR_NONE ? 0xffffffff : (u_int)options.escape_char); buffer_put_cstring(&m, term == NULL ? "" : term); buffer_put_string(&m, buffer_ptr(&command), buffer_len(&command)); if (options.num_send_env > 0 && environ != NULL) { /* Pass environment */ for (i = 0; environ[i] != NULL; i++) { if (env_permitted(environ[i])) { buffer_put_cstring(&m, environ[i]); } } } if (mux_client_write_packet(fd, &m) != 0) fatal("%s: write packet: %s", __func__, strerror(errno)); /* Send the stdio file descriptors */ if (mm_send_fd(fd, STDIN_FILENO) == -1 || mm_send_fd(fd, STDOUT_FILENO) == -1 || mm_send_fd(fd, STDERR_FILENO) == -1) fatal("%s: send fds failed", __func__); debug3("%s: session request sent", __func__); /* Read their reply */ buffer_clear(&m); if (mux_client_read_packet(fd, &m) != 0) { error("%s: read from master failed: %s", __func__, strerror(errno)); buffer_free(&m); return -1; } type = buffer_get_int(&m); if ((rid = buffer_get_int(&m)) != muxclient_request_id) fatal("%s: out of sequence reply: my id %u theirs %u", __func__, muxclient_request_id, rid); switch (type) { case MUX_S_SESSION_OPENED: sid = buffer_get_int(&m); debug("%s: master session id: %u", __func__, sid); break; case MUX_S_PERMISSION_DENIED: e = buffer_get_string(&m, NULL); buffer_free(&m); error("Master refused session request: %s", e); return -1; case MUX_S_FAILURE: e = buffer_get_string(&m, NULL); buffer_free(&m); error("%s: session request failed: %s", __func__, e); return -1; default: buffer_free(&m); error("%s: unexpected response from master 0x%08x", __func__, type); return -1; } muxclient_request_id++; signal(SIGHUP, control_client_sighandler); signal(SIGINT, control_client_sighandler); signal(SIGTERM, control_client_sighandler); signal(SIGWINCH, control_client_sigrelay); rawmode = tty_flag; if (tty_flag) enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); /* * Stick around until the controlee closes the client_fd. * Before it does, it is expected to write an exit message. * This process must read the value and wait for the closure of * the client_fd; if this one closes early, the multiplex master will * terminate early too (possibly losing data). */ for (exitval = 255, exitval_seen = 0;;) { buffer_clear(&m); if (mux_client_read_packet(fd, &m) != 0) break; type = buffer_get_int(&m); switch (type) { case MUX_S_TTY_ALLOC_FAIL: if ((esid = buffer_get_int(&m)) != sid) fatal("%s: tty alloc fail on unknown session: " "my id %u theirs %u", __func__, sid, esid); leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); rawmode = 0; continue; case MUX_S_EXIT_MESSAGE: if ((esid = buffer_get_int(&m)) != sid) fatal("%s: exit on unknown session: " "my id %u theirs %u", __func__, sid, esid); if (exitval_seen) fatal("%s: exitval sent twice", __func__); exitval = buffer_get_int(&m); exitval_seen = 1; continue; default: e = buffer_get_string(&m, NULL); fatal("%s: master returned error: %s", __func__, e); } } close(fd); if (rawmode) leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); if (muxclient_terminate) { debug2("Exiting on signal %ld", (long)muxclient_terminate); exitval = 255; } else if (!exitval_seen) { debug2("Control master terminated unexpectedly"); exitval = 255; } else debug2("Received exit status from master %d", exitval); if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET) fprintf(stderr, "Shared connection to %s closed.\r\n", host); exit(exitval); } static int mux_client_request_stdio_fwd(int fd) { Buffer m; char *e; u_int type, rid, sid; int devnull; debug3("%s: entering", __func__); if ((muxserver_pid = mux_client_request_alive(fd)) == 0) { error("%s: master alive request failed", __func__); return -1; } signal(SIGPIPE, SIG_IGN); if (stdin_null_flag) { if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1) fatal("open(/dev/null): %s", strerror(errno)); if (dup2(devnull, STDIN_FILENO) == -1) fatal("dup2: %s", strerror(errno)); if (devnull > STDERR_FILENO) close(devnull); } buffer_init(&m); buffer_put_int(&m, MUX_C_NEW_STDIO_FWD); buffer_put_int(&m, muxclient_request_id); buffer_put_cstring(&m, ""); /* reserved */ buffer_put_cstring(&m, stdio_forward_host); buffer_put_int(&m, stdio_forward_port); if (mux_client_write_packet(fd, &m) != 0) fatal("%s: write packet: %s", __func__, strerror(errno)); /* Send the stdio file descriptors */ if (mm_send_fd(fd, STDIN_FILENO) == -1 || mm_send_fd(fd, STDOUT_FILENO) == -1) fatal("%s: send fds failed", __func__); debug3("%s: stdio forward request sent", __func__); /* Read their reply */ buffer_clear(&m); if (mux_client_read_packet(fd, &m) != 0) { error("%s: read from master failed: %s", __func__, strerror(errno)); buffer_free(&m); return -1; } type = buffer_get_int(&m); if ((rid = buffer_get_int(&m)) != muxclient_request_id) fatal("%s: out of sequence reply: my id %u theirs %u", __func__, muxclient_request_id, rid); switch (type) { case MUX_S_SESSION_OPENED: sid = buffer_get_int(&m); debug("%s: master session id: %u", __func__, sid); break; case MUX_S_PERMISSION_DENIED: e = buffer_get_string(&m, NULL); buffer_free(&m); fatal("Master refused stdio forwarding request: %s", e); case MUX_S_FAILURE: e = buffer_get_string(&m, NULL); buffer_free(&m); fatal("%s: stdio forwarding request failed: %s", __func__, e); default: buffer_free(&m); error("%s: unexpected response from master 0x%08x", __func__, type); return -1; } muxclient_request_id++; signal(SIGHUP, control_client_sighandler); signal(SIGINT, control_client_sighandler); signal(SIGTERM, control_client_sighandler); signal(SIGWINCH, control_client_sigrelay); /* * Stick around until the controlee closes the client_fd. */ buffer_clear(&m); if (mux_client_read_packet(fd, &m) != 0) { if (errno == EPIPE || (errno == EINTR && muxclient_terminate != 0)) return 0; fatal("%s: mux_client_read_packet: %s", __func__, strerror(errno)); } fatal("%s: master returned unexpected message %u", __func__, type); } static void mux_client_request_stop_listening(int fd) { Buffer m; char *e; u_int type, rid; debug3("%s: entering", __func__); buffer_init(&m); buffer_put_int(&m, MUX_C_STOP_LISTENING); buffer_put_int(&m, muxclient_request_id); if (mux_client_write_packet(fd, &m) != 0) fatal("%s: write packet: %s", __func__, strerror(errno)); buffer_clear(&m); /* Read their reply */ if (mux_client_read_packet(fd, &m) != 0) fatal("%s: read from master failed: %s", __func__, strerror(errno)); type = buffer_get_int(&m); if ((rid = buffer_get_int(&m)) != muxclient_request_id) fatal("%s: out of sequence reply: my id %u theirs %u", __func__, muxclient_request_id, rid); switch (type) { case MUX_S_OK: break; case MUX_S_PERMISSION_DENIED: e = buffer_get_string(&m, NULL); fatal("Master refused stop listening request: %s", e); case MUX_S_FAILURE: e = buffer_get_string(&m, NULL); fatal("%s: stop listening request failed: %s", __func__, e); default: fatal("%s: unexpected response from master 0x%08x", __func__, type); } buffer_free(&m); muxclient_request_id++; } /* Multiplex client main loop. */ void muxclient(const char *path) { struct sockaddr_un addr; socklen_t sun_len; int sock; u_int pid; if (muxclient_command == 0) { if (stdio_forward_host != NULL) muxclient_command = SSHMUX_COMMAND_STDIO_FWD; else muxclient_command = SSHMUX_COMMAND_OPEN; } switch (options.control_master) { case SSHCTL_MASTER_AUTO: case SSHCTL_MASTER_AUTO_ASK: debug("auto-mux: Trying existing master"); /* FALLTHROUGH */ case SSHCTL_MASTER_NO: break; default: return; } memset(&addr, '\0', sizeof(addr)); addr.sun_family = AF_UNIX; sun_len = offsetof(struct sockaddr_un, sun_path) + strlen(path) + 1; if (strlcpy(addr.sun_path, path, sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) fatal("ControlPath too long"); if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) fatal("%s socket(): %s", __func__, strerror(errno)); if (connect(sock, (struct sockaddr *)&addr, sun_len) == -1) { switch (muxclient_command) { case SSHMUX_COMMAND_OPEN: case SSHMUX_COMMAND_STDIO_FWD: break; default: fatal("Control socket connect(%.100s): %s", path, strerror(errno)); } if (errno == ECONNREFUSED && options.control_master != SSHCTL_MASTER_NO) { debug("Stale control socket %.100s, unlinking", path); unlink(path); } else if (errno == ENOENT) { debug("Control socket \"%.100s\" does not exist", path); } else { error("Control socket connect(%.100s): %s", path, strerror(errno)); } close(sock); return; } set_nonblock(sock); if (mux_client_hello_exchange(sock) != 0) { error("%s: master hello exchange failed", __func__); close(sock); return; } switch (muxclient_command) { case SSHMUX_COMMAND_ALIVE_CHECK: if ((pid = mux_client_request_alive(sock)) == 0) fatal("%s: master alive check failed", __func__); fprintf(stderr, "Master running (pid=%d)\r\n", pid); exit(0); case SSHMUX_COMMAND_TERMINATE: mux_client_request_terminate(sock); fprintf(stderr, "Exit request sent.\r\n"); exit(0); case SSHMUX_COMMAND_FORWARD: if (mux_client_forwards(sock, 0) != 0) fatal("%s: master forward request failed", __func__); exit(0); case SSHMUX_COMMAND_OPEN: if (mux_client_forwards(sock, 0) != 0) { error("%s: master forward request failed", __func__); return; } mux_client_request_session(sock); return; case SSHMUX_COMMAND_STDIO_FWD: mux_client_request_stdio_fwd(sock); exit(0); case SSHMUX_COMMAND_STOP: mux_client_request_stop_listening(sock); fprintf(stderr, "Stop listening request sent.\r\n"); exit(0); case SSHMUX_COMMAND_CANCEL_FWD: if (mux_client_forwards(sock, 1) != 0) error("%s: master cancel forward request failed", __func__); exit(0); default: fatal("unrecognised muxclient_command %d", muxclient_command); } }