commit d035730ac7ebb82fbf1895fea50c29048bb6edb2
author Brian Smith <brian@briansmith.org> Fri Mar 25 10:11:04 2016 -1000
committer David Benjamin <davidben@google.com> Mon Apr 18 23:19:08 2016 +0000
tree e56505005fa06b932fba1ea93b3f5b15a109b662
parent 51b0d5b1e86590c6e828b11ede90db04916e9ff1

Make return value of |BN_MONT_CTX_set_locked| int.

This reduces the chance of double-frees.

BUG=10

Change-Id: I11a240e2ea5572effeddc05acb94db08c54a2e0b
Reviewed-on: https://boringssl-review.googlesource.com/7583
Reviewed-by: David Benjamin <davidben@google.com>

crypto/dsa/dsa.c

diff --git a/crypto/dsa/dsa.c b/crypto/dsa/dsa.c
index 979079d..fe29aa0 100644
--- a/crypto/dsa/dsa.c
+++ b/crypto/dsa/dsa.c
@@ -591,7 +591,6 @@
                            size_t digest_len, DSA_SIG *sig, const DSA *dsa) {
   BN_CTX *ctx;
   BIGNUM u1, u2, t1;
-  BN_MONT_CTX *mont = NULL;
   int ret = 0;
   unsigned i;
 
@@ -662,15 +661,14 @@
     goto err;
   }
 
-  mont = BN_MONT_CTX_set_locked((BN_MONT_CTX **)&dsa->method_mont_p,
-                                (CRYPTO_MUTEX *)&dsa->method_mont_p_lock,
-                                dsa->p, ctx);
-  if (!mont) {
+  if (!BN_MONT_CTX_set_locked((BN_MONT_CTX **)&dsa->method_mont_p,
+                              (CRYPTO_MUTEX *)&dsa->method_mont_p_lock, dsa->p,
+                              ctx)) {
     goto err;
   }
 
   if (!BN_mod_exp2_mont(&t1, dsa->g, &u1, dsa->pub_key, &u2, dsa->p, ctx,
-                        mont)) {
+                        dsa->method_mont_p)) {
     goto err;
   }
 
@@ -823,9 +821,9 @@
 
   BN_set_flags(&k, BN_FLG_CONSTTIME);
 
-  if (BN_MONT_CTX_set_locked((BN_MONT_CTX **)&dsa->method_mont_p,
-                             (CRYPTO_MUTEX *)&dsa->method_mont_p_lock, dsa->p,
-                             ctx) == NULL) {
+  if (!BN_MONT_CTX_set_locked((BN_MONT_CTX **)&dsa->method_mont_p,
+                              (CRYPTO_MUTEX *)&dsa->method_mont_p_lock, dsa->p,
+                              ctx)) {
     goto err;
   }