commit b8dc394ddfd58bc5d0fe9ecfc970fc42b789a9df
Author: Jeff Law <law@redhat.com>
Date: Fri Mar 30 09:45:44 2012 -0600
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.
diff --git a/crypt/md5-crypt.c b/crypt/md5-crypt.c
index ba606bb..db4ea9c 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;
}
diff --git a/crypt/sha256-crypt.c b/crypt/sha256-crypt.c
index eb2585b..440933a 100644
--- a/crypt/sha256-crypt.c
+++ b/crypt/sha256-crypt.c
@@ -1,5 +1,5 @@
/* One way encryption based on SHA256 sum.
- Copyright (C) 2007, 2009 Free Software Foundation, Inc.
+ Copyright (C) 2007, 2009, 2012 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2007.
@@ -122,6 +122,9 @@ __sha256_crypt_r (key, salt, buffer, buflen)
/* Default number of rounds. */
size_t rounds = ROUNDS_DEFAULT;
bool rounds_custom = false;
+ size_t alloca_used = 0;
+ char *free_key = NULL;
+ char *free_pbytes = NULL;
/* Find beginning of salt string. The prefix should normally always
be present. Just in case it is not. */
@@ -148,7 +151,17 @@ __sha256_crypt_r (key, salt, buffer, buflen)
if ((key - (char *) 0) % __alignof__ (uint32_t) != 0)
{
- char *tmp = (char *) alloca (key_len + __alignof__ (uint32_t));
+ char *tmp;
+
+ if (__libc_use_alloca (alloca_used + key_len + __alignof__ (uint32_t)))
+ tmp = alloca_account (key_len + __alignof__ (uint32_t), alloca_used);
+ else
+ {
+ free_key = tmp = (char *) malloc (key_len + __alignof__ (uint32_t));
+ if (tmp == NULL)
+ return NULL;
+ }
+
key = copied_key =
memcpy (tmp + __alignof__ (uint32_t)
- (tmp - (char *) 0) % __alignof__ (uint32_t),
@@ -159,6 +172,7 @@ __sha256_crypt_r (key, salt, buffer, buflen)
if ((salt - (char *) 0) % __alignof__ (uint32_t) != 0)
{
char *tmp = (char *) alloca (salt_len + __alignof__ (uint32_t));
+ alloca_used += salt_len + __alignof__ (uint32_t);
salt = copied_salt =
memcpy (tmp + __alignof__ (uint32_t)
- (tmp - (char *) 0) % __alignof__ (uint32_t),
@@ -170,7 +184,10 @@ __sha256_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
@@ -233,7 +250,18 @@ __sha256_crypt_r (key, salt, buffer, buflen)
sha256_finish_ctx (&alt_ctx, nss_alt_ctx, temp_result);
/* Create byte sequence P. */
- cp = p_bytes = alloca (key_len);
+ if (__libc_use_alloca (alloca_used + key_len))
+ cp = p_bytes = (char *) alloca (key_len);
+ else
+ {
+ free_pbytes = cp = p_bytes = (char *)malloc (key_len);
+ if (free_pbytes == NULL)
+ {
+ free (free_key);
+ return NULL;
+ }
+ }
+
for (cnt = key_len; cnt >= 32; cnt -= 32)
cp = mempcpy (cp, temp_result, 32);
memcpy (cp, temp_result, cnt);
@@ -361,6 +389,8 @@ __sha256_crypt_r (key, salt, buffer, buflen)
if (copied_salt != NULL)
memset (copied_salt, '\0', salt_len);
+ free (free_key);
+ free (free_pbytes);
return buffer;
}
diff --git a/crypt/sha512-crypt.c b/crypt/sha512-crypt.c
index 8f8ed33..e5d9cac 100644
--- a/crypt/sha512-crypt.c
+++ b/crypt/sha512-crypt.c
@@ -1,5 +1,5 @@
/* One way encryption based on SHA512 sum.
- Copyright (C) 2007, 2009 Free Software Foundation, Inc.
+ Copyright (C) 2007, 2009, 2012 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2007.
@@ -122,6 +122,9 @@ __sha512_crypt_r (key, salt, buffer, buflen)
/* Default number of rounds. */
size_t rounds = ROUNDS_DEFAULT;
bool rounds_custom = false;
+ size_t alloca_used = 0;
+ char *free_key = NULL;
+ char *free_pbytes = NULL;
/* Find beginning of salt string. The prefix should normally always
be present. Just in case it is not. */
@@ -148,7 +151,17 @@ __sha512_crypt_r (key, salt, buffer, buflen)
if ((key - (char *) 0) % __alignof__ (uint64_t) != 0)
{
- char *tmp = (char *) alloca (key_len + __alignof__ (uint64_t));
+ char *tmp;
+
+ if (__libc_use_alloca (alloca_used + key_len + __alignof__ (uint64_t)))
+ tmp = alloca_account (key_len + __alignof__ (uint64_t), alloca_used);
+ else
+ {
+ free_key = tmp = (char *) malloc (key_len + __alignof__ (uint64_t));
+ if (tmp == NULL)
+ return NULL;
+ }
+
key = copied_key =
memcpy (tmp + __alignof__ (uint64_t)
- (tmp - (char *) 0) % __alignof__ (uint64_t),
@@ -170,7 +183,10 @@ __sha512_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
@@ -233,7 +249,18 @@ __sha512_crypt_r (key, salt, buffer, buflen)
sha512_finish_ctx (&alt_ctx, nss_alt_ctx, temp_result);
/* Create byte sequence P. */
- cp = p_bytes = alloca (key_len);
+ if (__libc_use_alloca (alloca_used + key_len))
+ cp = p_bytes = (char *) alloca (key_len);
+ else
+ {
+ free_pbytes = cp = p_bytes = (char *)malloc (key_len);
+ if (free_pbytes == NULL)
+ {
+ free (free_key);
+ return NULL;
+ }
+ }
+
for (cnt = key_len; cnt >= 64; cnt -= 64)
cp = mempcpy (cp, temp_result, 64);
memcpy (cp, temp_result, cnt);
@@ -373,6 +400,8 @@ __sha512_crypt_r (key, salt, buffer, buflen)
if (copied_salt != NULL)
memset (copied_salt, '\0', salt_len);
+ free (free_key);
+ free (free_pbytes);
return buffer;
}