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| author | Jeff Law <law@redhat.com> | 2012-03-30 09:45:44 -0600 |
|---|---|---|
| committer | Jeff Law <law@redhat.com> | 2012-03-30 09:51:27 -0600 |
| commit | b8dc394ddfd58bc5d0fe9ecfc970fc42b789a9df (patch) | |
| tree | 5c0fd054db74a8ae8ad36c478b4f030b9da7b2fd /crypt/md5-crypt.c | |
| parent | 966977f1b72123bdd5187a60e9b50eaa70312d90 (diff) | |
| download | glibc-b8dc394ddfd58bc5d0fe9ecfc970fc42b789a9df.tar.gz glibc-b8dc394ddfd58bc5d0fe9ecfc970fc42b789a9df.tar.xz glibc-b8dc394ddfd58bc5d0fe9ecfc970fc42b789a9df.zip | |
2012-03-29 Jeff Law <law@redhat.com>
* crypt/md5-crypt.c (__md5_crypt_r): Avoid unbounded alloca uses due to long keys. * crypt/sha256-crypt.c (__sha256_crypt_r): Likewise. * crypt/sha512-crypt.c (__sha512_crypt_r): Likewise.
Diffstat (limited to 'crypt/md5-crypt.c')
| -rw-r--r-- | crypt/md5-crypt.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/crypt/md5-crypt.c b/crypt/md5-crypt.c index ba606bb8a6..db4ea9c6f1 100644 --- a/crypt/md5-crypt.c +++ b/crypt/md5-crypt.c @@ -1,6 +1,6 @@ /* One way encryption based on MD5 sum. Compatible with the behavior of MD5 crypt introduced in FreeBSD 2.0. - Copyright (C) 1996, 1997, 1999, 2000, 2001, 2002, 2004, 2009 + Copyright (C) 1996, 1997, 1999, 2000, 2001, 2002, 2004, 2009, 2012 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996. @@ -107,6 +107,8 @@ __md5_crypt_r (key, salt, buffer, buflen) char *cp; char *copied_key = NULL; char *copied_salt = NULL; + char *free_key = NULL; + size_t alloca_used = 0; /* Find beginning of salt string. The prefix should normally always be present. Just in case it is not. */ @@ -119,7 +121,17 @@ __md5_crypt_r (key, salt, buffer, buflen) if ((key - (char *) 0) % __alignof__ (md5_uint32) != 0) { - char *tmp = (char *) alloca (key_len + __alignof__ (md5_uint32)); + char *tmp; + + if (__libc_use_alloca (alloca_used + key_len + __alignof__ (md5_uint32))) + tmp = (char *) alloca (key_len + __alignof__ (md5_uint32)); + else + { + free_key = tmp = (char *) malloc (key_len + __alignof__ (md5_uint32)); + if (tmp == NULL) + return NULL; + } + key = copied_key = memcpy (tmp + __alignof__ (md5_uint32) - (tmp - (char *) 0) % __alignof__ (md5_uint32), @@ -141,7 +153,10 @@ __md5_crypt_r (key, salt, buffer, buflen) /* Initialize libfreebl3. */ NSSLOWInitContext *nss_ictx = NSSLOW_Init (); if (nss_ictx == NULL) - return NULL; + { + free (free_key); + return NULL; + } NSSLOWHASHContext *nss_ctx = NULL; NSSLOWHASHContext *nss_alt_ctx = NULL; #else @@ -295,6 +310,7 @@ __md5_crypt_r (key, salt, buffer, buflen) if (copied_salt != NULL) memset (copied_salt, '\0', salt_len); + free (free_key); return buffer; } |