commit 7c21925a10d451ed13ab201e0161dea40b974397
author Adam Langley <agl@google.com> Tue Feb 24 14:30:15 2015 -0800
committer Adam Langley <agl@google.com> Wed Feb 25 21:13:02 2015 +0000
tree 62dcd96d3a57d2f637d327d7f16434ab02b030a1
parent 3ce3c369cb05b4ba9dcaad79b552713e7fa3581f

EC_GROUP_cmp should return zero if the groups match.

(I got this wrong when reading the OpenSSL code.)

Change-Id: Ib289ef41d0ab5a3157ad8b9454d2de96d1f86c22
Reviewed-on: https://boringssl-review.googlesource.com/3620
Reviewed-by: Adam Langley <agl@google.com>

crypto/ec/ec.c

diff --git a/crypto/ec/ec.c b/crypto/ec/ec.c
index 21a3940..ad47bb5 100644
--- a/crypto/ec/ec.c
+++ b/crypto/ec/ec.c
@@ -500,10 +500,9 @@
 }
 
 int EC_GROUP_cmp(const EC_GROUP *a, const EC_GROUP *b, BN_CTX *ignored) {
-  if (a->curve_name == NID_undef || b->curve_name == NID_undef) {
-    return 0;
-  }
-  return a->curve_name == b->curve_name;
+  return a->curve_name == NID_undef ||
+         b->curve_name == NID_undef ||
+         a->curve_name != b->curve_name;
 }
 
 const EC_POINT *EC_GROUP_get0_generator(const EC_GROUP *group) {

crypto/evp/p_ec_asn1.c

diff --git a/crypto/evp/p_ec_asn1.c b/crypto/evp/p_ec_asn1.c
index 8967b50..670ee74 100644
--- a/crypto/evp/p_ec_asn1.c
+++ b/crypto/evp/p_ec_asn1.c
@@ -382,7 +382,11 @@
 static int ec_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b) {
   const EC_GROUP *group_a = EC_KEY_get0_group(a->pkey.ec),
                  *group_b = EC_KEY_get0_group(b->pkey.ec);
-  return EC_GROUP_cmp(group_a, group_b, NULL);
+  if (EC_GROUP_cmp(group_a, group_b, NULL) != 0) {
+    /* mismatch */
+    return 0;
+  }
+  return 1;
 }
 
 static void int_ec_free(EVP_PKEY *pkey) { EC_KEY_free(pkey->pkey.ec); }

include/openssl/ec.h

diff --git a/include/openssl/ec.h b/include/openssl/ec.h
index c952d9a..318ce0f 100644
--- a/include/openssl/ec.h
+++ b/include/openssl/ec.h
@@ -115,7 +115,7 @@
  * error. */
 OPENSSL_EXPORT EC_GROUP *EC_GROUP_dup(const EC_GROUP *a);
 
-/* EC_GROUP_cmp returns one if |a| and |b| are the same group and zero
+/* EC_GROUP_cmp returns zero if |a| and |b| are the same group and non-zero
  * otherwise. */
 OPENSSL_EXPORT int EC_GROUP_cmp(const EC_GROUP *a, const EC_GROUP *b,
                                 BN_CTX *ignored);