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sbin/geom/class/eli/geom_eli.c

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#include "misc/subr.h" #include "misc/subr.h"
uint32_t lib_version = G_LIB_VERSION; uint32_t lib_version = G_LIB_VERSION;
uint32_t version = G_ELI_VERSION; uint32_t version = G_ELI_VERSION;
#define GELI_BACKUP_DIR "/var/backups/" #define GELI_BACKUP_DIR "/var/backups/"
#define GELI_ENC_ALGO "aes" #define GELI_ENC_ALGO "aes"
#define BUFSIZE 1024
/*
* Passphrase cached when attaching multiple providers, in order to be more
* user-friendly if they are using the same passphrase.
*/
static char cached_passphrase[BUFSIZE] = "";
static void eli_main(struct gctl_req *req, unsigned flags); static void eli_main(struct gctl_req *req, unsigned flags);
static void eli_init(struct gctl_req *req); static void eli_init(struct gctl_req *req);
static void eli_attach(struct gctl_req *req); static void eli_attach(struct gctl_req *req);
static void eli_configure(struct gctl_req *req); static void eli_configure(struct gctl_req *req);
static void eli_setkey(struct gctl_req *req); static void eli_setkey(struct gctl_req *req);
static void eli_delkey(struct gctl_req *req); static void eli_delkey(struct gctl_req *req);
static void eli_resume(struct gctl_req *req); static void eli_resume(struct gctl_req *req);
static void eli_kill(struct gctl_req *req); static void eli_kill(struct gctl_req *req);
static void eli_backup(struct gctl_req *req); static void eli_backup(struct gctl_req *req);
static void eli_restore(struct gctl_req *req); static void eli_restore(struct gctl_req *req);
static void eli_resize(struct gctl_req *req); static void eli_resize(struct gctl_req *req);
static void eli_version(struct gctl_req *req); static void eli_version(struct gctl_req *req);
static void eli_clear(struct gctl_req *req); static void eli_clear(struct gctl_req *req);
static void eli_dump(struct gctl_req *req); static void eli_dump(struct gctl_req *req);
static int eli_backup_create(struct gctl_req *req, const char *prov, static int eli_backup_create(struct gctl_req *req, const char *prov,
const char *file); const char *file);
/* /*
* Available commands: * Available commands:
* *
* init [-bdgPTv] [-a aalgo] [-B backupfile] [-e ealgo] [-i iterations] [-l keylen] [-J newpassfile] [-K newkeyfile] [-s sectorsize] [-V version] prov * init [-bdgPTv] [-a aalgo] [-B backupfile] [-e ealgo] [-i iterations] [-l keylen] [-J newpassfile] [-K newkeyfile] [-s sectorsize] [-V version] prov
* label - alias for 'init' * label - alias for 'init'
* attach [-dprv] [-j passfile] [-k keyfile] prov * attach [-dprv] [-j passfile] [-k keyfile] prov ...
* detach [-fl] prov ... * detach [-fl] prov ...
* stop - alias for 'detach' * stop - alias for 'detach'
* onetime [-d] [-a aalgo] [-e ealgo] [-l keylen] prov * onetime [-d] [-a aalgo] [-e ealgo] [-l keylen] prov
* configure [-bBgGtT] prov ... * configure [-bBgGtT] prov ...
* setkey [-pPv] [-n keyno] [-j passfile] [-J newpassfile] [-k keyfile] [-K newkeyfile] prov * setkey [-pPv] [-n keyno] [-j passfile] [-J newpassfile] [-k keyfile] [-K newkeyfile] prov
* delkey [-afv] [-n keyno] prov * delkey [-afv] [-n keyno] prov
* suspend [-v] -a | prov ... * suspend [-v] -a | prov ...
* resume [-pv] [-j passfile] [-k keyfile] prov * resume [-pv] [-j passfile] [-k keyfile] prov
▲ Show 20 Lines • Show All 170 Lines • ▼ Show 20 Linesstruct g_command class_commands[] = {
{ "dump", G_FLAG_VERBOSE, eli_main, G_NULL_OPTS, { "dump", G_FLAG_VERBOSE, eli_main, G_NULL_OPTS,
"[-v] prov ..." "[-v] prov ..."
}, },
G_CMD_SENTINEL G_CMD_SENTINEL
}; };
static int verbose = 0; static int verbose = 0;
#define BUFSIZE 1024
static int static int
eli_protect(struct gctl_req *req) eli_protect(struct gctl_req *req)
{ {
struct rlimit rl; struct rlimit rl;
/* Disable core dumps. */ /* Disable core dumps. */
rl.rlim_cur = 0; rl.rlim_cur = 0;
rl.rlim_max = 0; rl.rlim_max = 0;
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static int static int
eli_genkey_passphrase(struct gctl_req *req, struct g_eli_metadata *md, bool new, eli_genkey_passphrase(struct gctl_req *req, struct g_eli_metadata *md, bool new,
struct hmac_ctx *ctxp) struct hmac_ctx *ctxp)
{ {
char passbuf[BUFSIZE]; char passbuf[BUFSIZE];
bool nopassphrase; bool nopassphrase;
int nfiles; int nfiles;
/*
* Return error if the 'do not use passphrase' flag was given but a
wblockUnsubmitted
Done
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* Return error if the 'do not use passphrase' flag is given but a
wblock: ```* Return error if the 'do not use passphrase' flag is given but a
* passfile was provided.
*/
nopassphrase = nopassphrase =
gctl_get_int(req, new ? "nonewpassphrase" : "nopassphrase"); gctl_get_int(req, new ? "nonewpassphrase" : "nopassphrase");
if (nopassphrase) { if (nopassphrase) {
if (gctl_has_param(req, new ? "newpassfile0" : "passfile0")) { if (gctl_has_param(req, new ? "newpassfile0" : "passfile0")) {
gctl_error(req, gctl_error(req,
"Options -%c and -%c are mutually exclusive.", "Options -%c and -%c are mutually exclusive.",
new ? 'J' : 'j', new ? 'P' : 'p'); new ? 'J' : 'j', new ? 'P' : 'p');
return (-1); return (-1);
} }
return (0); return (0);
} }
/*
* Return error if using a provider which does not require a passphrase
wblockUnsubmitted
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s/,//

wblock: s/,//
* but the 'do not use passphrase' flag was not given.
*/
if (!new && md->md_iterations == -1) { if (!new && md->md_iterations == -1) {
gctl_error(req, "Missing -p flag."); gctl_error(req, "Missing -p flag.");
return (-1); return (-1);
} }
passbuf[0] = '\0'; passbuf[0] = '\0';
/* Use cached passphrase if defined. */
if (strlen(cached_passphrase) > 0) {
sobomaxUnsubmitted
Done
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strlen(cached_passphrase) > 0

or

cached_passphrase[0] != '\0'
sobomax: ``` strlen(cached_passphrase) > 0 ``` or ``` cached_passphrase[0] != '\0' ```
strlcpy(passbuf, cached_passphrase, sizeof(passbuf));
sobomaxUnsubmitted
Done
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srlcpy(passbuf, cached_passphrase, sizeof(passbuf));
sobomax: ``` srlcpy(passbuf, cached_passphrase, sizeof(passbuf)); ```
} else {
nfiles = eli_genkey_files(req, new, "passfile", NULL, passbuf, nfiles = eli_genkey_files(req, new, "passfile", NULL, passbuf,
sizeof(passbuf)); sizeof(passbuf));
if (nfiles == -1) if (nfiles == -1)
return (-1); return (-1);
else if (nfiles == 0) { else if (nfiles == 0) {
if (eli_genkey_passphrase_prompt(req, new, passbuf, if (eli_genkey_passphrase_prompt(req, new, passbuf,
sizeof(passbuf)) == -1) { sizeof(passbuf)) == -1) {
return (-1); return (-1);
} }
} }
/* Cache the passphrase for other providers. */
strlcpy(cached_passphrase, passbuf, sizeof(cached_passphrase));
sobomaxUnsubmitted
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srlcpy(passbuf, cached_passphrase, sizeof(passbuf));
sobomax: ``` srlcpy(passbuf, cached_passphrase, sizeof(passbuf)); ```
sobomaxUnsubmitted
Done
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Sorry, actually should be (note sizeof() of wrong argument, should be size of the DESTINATION buffer:

srlcpy(cached_passphrase, passbuf, sizeof(cached_passphrase));
sobomax: Sorry, actually should be (note sizeof() of wrong argument, should be size of the DESTINATION…
}
/* /*
* Field md_iterations equal to -1 means "choose some sane * Field md_iterations equal to -1 means "choose some sane
* value for me". * value for me".
*/ */
if (md->md_iterations == -1) { if (md->md_iterations == -1) {
assert(new); assert(new);
if (verbose) if (verbose)
printf("Calculating number of iterations...\n"); printf("Calculating number of iterations...\n");
▲ Show 20 Lines • Show All 361 Lines • ▼ Show 20 Lines if (strcmp(backfile, "none") != 0 &&
printf("\n\t# geli restore %s %s\n\n", backfile, prov); printf("\n\t# geli restore %s %s\n\n", backfile, prov);
} }
} }
static void static void
eli_attach(struct gctl_req *req) eli_attach(struct gctl_req *req)
{ {
struct g_eli_metadata md; struct g_eli_metadata md;
unsigned char key[G_ELI_USERKEYLEN];
const char *prov; const char *prov;
off_t mediasize; off_t mediasize;
int nargs; char param[16];
int i, nargs;
nargs = gctl_get_int(req, "nargs"); nargs = gctl_get_int(req, "nargs");
if (nargs != 1) { if (nargs == 0) {
gctl_error(req, "Invalid number of arguments."); gctl_error(req, "Too few arguments.");
return; return;
} }
prov = gctl_get_ascii(req, "arg0");
/* Use a 2D array for storing the derived keys (1 row per provider) */
unsigned char key[nargs][G_ELI_USERKEYLEN];
delphijUnsubmitted
Done
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Why do we need an array (versus just doing these operations in one single loop, and discard the key right after each gctl_issue) here? The "Attached to" and "\n" can be done by checking i's value below.

The benefit of doing the loop is that we would be able to distinguish individual failures.

delphij: Why do we need an array (versus just doing these operations in one single loop, and discard the…
woodsb02AuthorUnsubmitted
Done
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This is because the geom request is passed to the kernel with all of the providers listed on the command line. Without this change the kernel errors out if there is more than one provider listed.

I have also submitted an alternative implementation of this change which does not modify the kernel. Instead it creates new child geom requests and issues them to the kernel one-by-one.

See D12644.

woodsb02: This is because the geom request is passed to the kernel with all of the providers listed on…
/* Generate the derived key for each provider */
for (i = 0; i < nargs; i++) {
prov = gctl_get_ascii(req, "arg%d", i);
if (eli_metadata_read(req, prov, &md) == -1) if (eli_metadata_read(req, prov, &md) == -1)
return; return;
mediasize = g_get_mediasize(prov); mediasize = g_get_mediasize(prov);
if (md.md_provsize != (uint64_t)mediasize) { if (md.md_provsize != (uint64_t)mediasize) {
gctl_error(req, "Provider size mismatch."); gctl_error(req, "Provider size mismatch.");
return; return;
} }
if (eli_genkey(req, &md, key, false) == NULL) { if (eli_genkey(req, &md, key[i], false) == NULL) {
bzero(key, sizeof(key)); bzero(key, sizeof(key));
return; return;
} }
gctl_ro_param(req, "key", sizeof(key), key); snprintf(param, sizeof(param), "key%d", i);
gctl_ro_param(req, param, sizeof(key[i]), key[i]);
}
if (gctl_issue(req) == NULL) { if (gctl_issue(req) == NULL) {
if (verbose) if (verbose) {
printf("Attached to %s.\n", prov); printf("Attached to");
for (i = 0; i < nargs; i++) {
printf(" %s", gctl_get_ascii(req, "arg%d", i));
} }
printf(".\n");
}
}
/* Clear each of the derived keys from the 2D array */
bzero(key, sizeof(key)); bzero(key, sizeof(key));
delphijUnsubmitted
Done
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Unrelated to your change, but 'key' is on stack and therefore explicit_bzero() should be used, or it could be optimized away because key is undefined once out of scope.

delphij: Unrelated to your change, but 'key' is on stack and therefore explicit_bzero() should be used…
woodsb02AuthorUnsubmitted
Done
Inline Actions

That seems like the right idea.
There are 39 instances of bzero in sbin/geom/class/eli/geom_eli.c, of which 22 remain after removing those for the provider metadata (including salt) and sector buffer (for storing metadata to disk).
Do you think I should change all 39 to explicit_bzero, the 22, just mine, or none for now?

woodsb02: That seems like the right idea. There are 39 instances of bzero in sbin/geom/class/eli/geom_eli.
/* Clear the cached passphrase */
bzero(cached_passphrase, sizeof(cached_passphrase));
sobomaxUnsubmitted
Done
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Not sure if you need to zero-out the whole buf.

cached_passphrase[0] = '\0'

might suffice.

sobomax: Not sure if you need to zero-out the whole buf. ``` cached_passphrase[0] = '\0' ``` might…
woodsb02AuthorUnsubmitted
Done
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I think the entire passphrase should be zeroed out, to prevent it sticking around in memory in clear text.

woodsb02: I think the entire passphrase should be zeroed out, to prevent it sticking around in memory in…
delphijUnsubmitted
Done
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I agree (if I was you I would use explicit_bzero() here too, but it would be a bug of the compiler if it optimize the bzero() away).

delphij: I agree (if I was you I would use explicit_bzero() here too, but it would be a bug of the…
} }
static void static void
eli_configure_detached(struct gctl_req *req, const char *prov, int boot, eli_configure_detached(struct gctl_req *req, const char *prov, int boot,
int geliboot, int displaypass, int trim) int geliboot, int displaypass, int trim)
{ {
struct g_eli_metadata md; struct g_eli_metadata md;
bool changed = 0; bool changed = 0;
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