int e4crypt_delete_user_key(const char *user_handle) {
SLOGD("e4crypt_delete_user_key(\"%s\")", user_handle);
auto key_path = get_key_path(DATA_MNT_POINT, user_handle);
auto key = e4crypt_get_key(key_path, false);
auto ext4_key = fill_key(key);
auto ref = keyname(generate_key_ref(ext4_key.raw, ext4_key.size));
auto key_serial = keyctl_search(e4crypt_keyring(), "logon", ref.c_str(), 0);
if (keyctl_revoke(key_serial) == 0) {
SLOGD("Revoked key with serial %ld ref %s\n", key_serial, ref.c_str());
} else {
SLOGE("Failed to revoke key with serial %ld ref %s: %s\n",
key_serial, ref.c_str(), strerror(errno));
}
int pid = fork();
if (pid < 0) {
SLOGE("Unable to fork: %s", strerror(errno));
return -1;
}
if (pid == 0) {
SLOGD("Forked for secdiscard");
execl("/system/bin/secdiscard",
"/system/bin/secdiscard",
key_path.c_str(),
NULL);
SLOGE("Unable to launch secdiscard on %s: %s\n", key_path.c_str(),
strerror(errno));
exit(-1);
}
// ext4enc:TODO reap the zombie
return 0;
}
/*
* Revoke a key
*/
static int key_invalidate(char *keystr, int keymask)
{
FILE *fp;
char buf[BUFSIZ], *ptr;
key_serial_t key;
int mask;
xlog_syslog(0);
if ((fp = fopen(PROCKEYS, "r")) == NULL) {
xlog_err("fopen(%s) failed: %m", PROCKEYS);
return EXIT_FAILURE;
}
while(fgets(buf, BUFSIZ, fp) != NULL) {
if (strstr(buf, "keyring") != NULL)
continue;
mask = 0;
if ((ptr = strstr(buf, "uid:")) != NULL)
mask = UIDKEYS;
else if ((ptr = strstr(buf, "gid:")) != NULL)
mask = GIDKEYS;
else
continue;
if ((keymask & mask) == 0)
continue;
if (strncmp(ptr+4, keystr, strlen(keystr)) != 0)
continue;
if (verbose) {
*(strchr(buf, '\n')) = '\0';
xlog_warn("invalidating '%s'", buf);
}
/*
* The key is the first arugment in the string
*/
*(strchr(buf, ' ')) = '\0';
sscanf(buf, "%x", &key);
/* older libkeyutils compatibility */
#ifndef KEYCTL_INVALIDATE
#define KEYCTL_INVALIDATE 21 /* invalidate a key */
#endif
if (keyctl(KEYCTL_INVALIDATE, key) < 0) {
if (errno != EOPNOTSUPP) {
xlog_err("keyctl_invalidate(0x%x) failed: %m", key);
fclose(fp);
return EXIT_FAILURE;
} else {
/* older kernel compatibility attempt: */
if (keyctl_revoke(key) < 0) {
xlog_err("keyctl_revoke(0x%x) failed: %m", key);
fclose(fp);
return EXIT_FAILURE;
}
}
}
keymask &= ~mask;
if (keymask == 0) {
fclose(fp);
return EXIT_SUCCESS;
}
}
xlog_err("'%s' key was not found.", keystr);
fclose(fp);
return EXIT_FAILURE;
}
int
main(int argc, char *argv[])
{
int ret = 1;
char *secret_cmd = NULL;
char *subprocess_argv[4];
struct sm_opts *opts = NULL;
key_serial_t key_id;
char key_payload[KEY_PAYLOAD_MAXLEN];
char session_name[SESSION_NAME_MAXLEN];
// parse_opts gives use default values if not provided
opts = sm_opts_parse(argc, argv);
if (opts == NULL) {
ret = 1;
goto exit;
}
if (opts->flags & OPT_HELP || opts->flags & OPT_UNRECOGNIZED) {
print_usage();
ret = 0;
goto exit;
}
if (opts->flags & OPT_VERSION) {
fprintf(stderr, PACKAGE_NAME " " PACKAGE_VERSION "\n");
ret = 0;
goto exit;
}
// We deal with only one session name for the moment
sprintf(session_name, "sm-session-%u", SM_MAGIC);
// Start to request a key in the current session if present
key_id = request_key("user", session_name, NULL, KEY_SPEC_SESSION_KEYRING);
if (opts->flags & OPT_QUIT ) {
if (key_id > 0)
keyctl_revoke(key_id);
else
fprintf(stderr, "No keyring session could be found.\n");
ret = 0;
goto exit;
}
if (opts->flags & OPT_SHOW_KEYID) {
if (key_id > 0) {
printf("%d\n", key_id);
ret = 0;
goto exit;
} else {
fprintf(stderr, "No key is attached to the current session.\n");
ret = 1;
goto exit;
}
}
if (key_id <= 0) {
// Ask the user to enter his secret phrase and
memset(key_payload, 0, KEY_PAYLOAD_MAXLEN);
sprintf(key_payload, "%s", getpass("Secret: "));
if (strlen(key_payload) == 0) {
fprintf(stderr, "An empty secret phrase is not supported.\n");
ret = 1;
goto exit;
}
key_id = add_key("user", session_name, key_payload,
strlen(key_payload), KEY_SPEC_SESSION_KEYRING);
if (key_id < 0) {
fprintf(stderr, "FATAL: Cannot add a passphrase, is CONFIG_KEYS enabled in your kernel?\n");
ret = 1;
goto exit;
}
// To be able to find again the passphrase in the next execution of sm,
// we have to attach the current keyring session to the shell
// interpreter which executed this cmd
keyctl_session_to_parent();
} else {
// Read the passphrase
memset(key_payload, 0, KEY_PAYLOAD_MAXLEN);
if (keyctl_read(key_id, key_payload, KEY_PAYLOAD_MAXLEN) < 0) {
ret = 1;
goto exit;
}
}
// We should have here a valid key id, so trigger the timeout again
keyctl_set_timeout(key_id, (unsigned int) opts->timeout_sec);
// Replace all {} occurrences by the secret phrase
secret_cmd = replace_str(opts->cmd, opts->repl_str, key_payload);
// Execute the secret cmd
if (secret_cmd) {
// Replacing the current executable image will at least return the exit
// code of the executed command
subprocess_argv[0] = "sh";
subprocess_argv[1] = "-c";
subprocess_argv[2] = secret_cmd;
subprocess_argv[3] = NULL;
execvp("/bin/sh", subprocess_argv);
assert(0);
}
exit:
if (opts)
sm_opts_free(opts);
return ret;
}
/*
* Revoke a key
*/
static int key_invalidate(char *keystr, int keymask)
{
FILE *fp;
char buf[BUFSIZ], *ptr;
key_serial_t key;
int mask;
xlog_syslog(0);
if ((fp = fopen(PROCKEYS, "r")) == NULL) {
xlog_err("fopen(%s) failed: %m", PROCKEYS);
return 1;
}
while(fgets(buf, BUFSIZ, fp) != NULL) {
if (strstr(buf, "keyring") != NULL)
continue;
mask = 0;
if ((ptr = strstr(buf, "uid:")) != NULL)
mask = UIDKEYS;
else if ((ptr = strstr(buf, "gid:")) != NULL)
mask = GIDKEYS;
else
continue;
if ((keymask & mask) == 0)
continue;
if (strncmp(ptr+4, keystr, strlen(keystr)) != 0)
continue;
if (verbose) {
*(strchr(buf, '\n')) = '\0';
xlog_warn("invalidating '%s'", buf);
}
/*
* The key is the first arugment in the string
*/
*(strchr(buf, ' ')) = '\0';
sscanf(buf, "%x", &key);
#ifdef HAVE_KEYCTL_INVALIDATE
#warning Using keyctl-invalidate (yay!).
if (keyctl_invalidate(key) < 0) {
xlog_err("keyctl_invalidate(0x%x) failed: %m", key);
fclose(fp);
return 1;
}
#else
#ifdef HAVE_KEYCTL_REVOKE
#warning Using keyctl-revoke because keyctl-invalidate is not available.
if (keyctl_revoke(key) < 0) {
xlog_err("keyctl_invalidate(0x%x) failed: %m", key);
fclose(fp);
return 1;
}
#else
#error "Need keyctl_revoke or keyctl_invalidate."
#endif
#endif
keymask &= ~mask;
if (keymask == 0) {
fclose(fp);
return 0;
}
}
xlog_err("'%s' key was not found.", keystr);
fclose(fp);
return 1;
}
