diff options
Diffstat (limited to 'source4/passdb/secrets.c')
| -rw-r--r-- | source4/passdb/secrets.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/source4/passdb/secrets.c b/source4/passdb/secrets.c index b5bae614b6..21938db154 100644 --- a/source4/passdb/secrets.c +++ b/source4/passdb/secrets.c @@ -29,10 +29,27 @@ static TDB_CONTEXT *tdb; +/** + * Use a TDB to store an incrementing random seed. + * + * Initialised to the current pid, the very first time Samba starts, + * and incremented by one each time it is needed. + * + * @note Not called by systems with a working /dev/urandom. + */ +static void get_rand_seed(int *new_seed) +{ + *new_seed = getpid(); + if (tdb) { + tdb_change_int32_atomic(tdb, "INFO/random_seed", new_seed, 1); + } +} + /* open up the secrets database */ BOOL secrets_init(void) { pstring fname; + char dummy; if (tdb) return True; @@ -46,6 +63,18 @@ BOOL secrets_init(void) DEBUG(0,("Failed to open %s\n", fname)); return False; } + + /** + * Set a reseed function for the crypto random generator + * + * This avoids a problem where systems without /dev/urandom + * could send the same challenge to multiple clients + */ + set_rand_reseed_callback(get_rand_seed); + + /* Ensure that the reseed is done now, while we are root, etc */ + generate_random_buffer(&dummy, sizeof(dummy)); + return True; } |