pgcrypto crypt()/md5 and hmac() leak memory when compiled against
OpenSSL as openssl.c digest -reset will do two DigestInit calls
against a context. This happened to work with OpenSSL 0.9.6
but not with 0.9.7+.
Reason for the messy code was that I tried to avoid creating
wrapper structure to transport algorithm info and tried to use
OpenSSL context for it. The fix is to create wrapper structure.
It also uses newer digest API to avoid memory allocations
on reset with newer OpenSSLs.
Attached are one patch for 7.3, 7.4, 8.0 branches and another
for 8.1 and HEAD.
Thanks to Daniel Blaisdell for reporting it.
--
marko
Index: contrib/pgcrypto/openssl.c
===
RCS file: /opt/cvs/pgsql/contrib/pgcrypto/openssl.c,v
retrieving revision 1.12.4.1
diff -u -c -r1.12.4.1 openssl.c
*** contrib/pgcrypto/openssl.c 12 Mar 2005 06:55:14 - 1.12.4.1
--- contrib/pgcrypto/openssl.c 17 Feb 2006 23:31:29 -
***
*** 36,95
#include openssl/evp.h
/*
* Hashes
*/
static unsigned
digest_result_size(PX_MD * h)
{
! return EVP_MD_CTX_size((EVP_MD_CTX *) h-p.ptr);
}
static unsigned
digest_block_size(PX_MD * h)
{
! return EVP_MD_CTX_block_size((EVP_MD_CTX *) h-p.ptr);
}
static void
digest_reset(PX_MD * h)
{
! EVP_MD_CTX *ctx = (EVP_MD_CTX *) h-p.ptr;
! const EVP_MD *md;
! md = EVP_MD_CTX_md(ctx);
!
! EVP_DigestInit(ctx, md);
}
static void
digest_update(PX_MD * h, const uint8 *data, unsigned dlen)
{
! EVP_MD_CTX *ctx = (EVP_MD_CTX *) h-p.ptr;
! EVP_DigestUpdate(ctx, data, dlen);
}
static void
digest_finish(PX_MD * h, uint8 *dst)
{
! EVP_MD_CTX *ctx = (EVP_MD_CTX *) h-p.ptr;
! const EVP_MD *md = EVP_MD_CTX_md(ctx);
!
! EVP_DigestFinal(ctx, dst, NULL);
! /*
! * Some builds of 0.9.7x clear all of ctx in EVP_DigestFinal.
! * Fix it by reinitializing ctx.
! */
! EVP_DigestInit(ctx, md);
}
static void
digest_free(PX_MD * h)
{
! EVP_MD_CTX *ctx = (EVP_MD_CTX *) h-p.ptr;
! px_free(ctx);
px_free(h);
}
--- 36,124
#include openssl/evp.h
/*
+ * Backwards compatibility code for digest.
+ */
+ #if OPENSSL_VERSION_NUMBER 0x00907000L
+
+ static void EVP_MD_CTX_init(EVP_MD_CTX *ctx)
+ {
+ memset(ctx, 0, sizeof(*ctx));
+ }
+
+ static int EVP_MD_CTX_cleanup(EVP_MD_CTX *ctx)
+ {
+ memset(ctx, 0, sizeof(*ctx));
+ return 1;
+ }
+
+ static int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *md, void *engine)
+ {
+ EVP_DigestInit(ctx, md);
+ return 1;
+ }
+
+ static int EVP_DigestFinal_ex(EVP_MD_CTX *ctx, unsigned char *res, unsigned int *len)
+ {
+ EVP_DigestFinal(ctx, res, len);
+ return 1;
+ }
+
+ #endif
+
+ /*
* Hashes
*/
+
+ typedef struct OSSLDigest {
+ const EVP_MD *algo;
+ EVP_MD_CTX ctx;
+ } OSSLDigest;
+
static unsigned
digest_result_size(PX_MD * h)
{
! OSSLDigest *digest = (OSSLDigest *)h-p.ptr;
! return EVP_MD_CTX_size(digest-ctx);
}
static unsigned
digest_block_size(PX_MD * h)
{
! OSSLDigest *digest = (OSSLDigest *)h-p.ptr;
! return EVP_MD_CTX_block_size(digest-ctx);
}
static void
digest_reset(PX_MD * h)
{
! OSSLDigest *digest = (OSSLDigest *)h-p.ptr;
! EVP_DigestInit_ex(digest-ctx, digest-algo, NULL);
}
static void
digest_update(PX_MD * h, const uint8 *data, unsigned dlen)
{
! OSSLDigest *digest = (OSSLDigest *)h-p.ptr;
! EVP_DigestUpdate(digest-ctx, data, dlen);
}
static void
digest_finish(PX_MD * h, uint8 *dst)
{
! OSSLDigest *digest = (OSSLDigest *)h-p.ptr;
! EVP_DigestFinal_ex(digest-ctx, dst, NULL);
}
static void
digest_free(PX_MD * h)
{
! OSSLDigest *digest = (OSSLDigest *)h-p.ptr;
! EVP_MD_CTX_cleanup(digest-ctx);
! px_free(digest);
px_free(h);
}
***
*** 101,108
px_find_digest(const char *name, PX_MD ** res)
{
const EVP_MD *md;
- EVP_MD_CTX *ctx;
PX_MD *h;
if (!px_openssl_initialized)
{
--- 130,137
px_find_digest(const char *name, PX_MD ** res)
{
const EVP_MD *md;
PX_MD *h;
+ OSSLDigest *digest;
if (!px_openssl_initialized)
{
***
*** 114,121
if (md == NULL)
return -1;
! ctx = px_alloc(sizeof(*ctx));
! EVP_DigestInit(ctx, md);
h = px_alloc(sizeof(*h));
h-result_size = digest_result_size;
--- 143,154
if (md == NULL)
return -1;
! digest = px_alloc(sizeof(*digest));
! digest-algo = md;
!
! EVP_MD_CTX_init(digest-ctx);
! if (EVP_DigestInit_ex(digest-ctx, digest-algo, NULL) == 0)
! return -1;
h = px_alloc(sizeof(*h));
h-result_size = digest_result_size;
***
*** 124,130
h-update = digest_update;
h-finish = digest_finish;
h-free = digest_free;
! h-p.ptr = (void *) ctx;
*res = h;
return 0;
--- 157,163
h-update = digest_update;
h-finish = digest_finish;
h-free = digest_free;
! h-p.ptr = (void *) digest;
*res = h;
return 0;
