Fix an incorrect error check in DSA verify.

From Matt Caswell's OpenSSL commit "RT3192: spurious error in DSA verify".

https://github.com/openssl/openssl/commit/eb63bce040d1cc6147d256f516b59552c018e29b

1 files changed, 2 insertions, 4 deletions

diff --git a/src/lib/libcrypto/dsa/dsa_ossl.c b/src/lib/libcrypto/dsa/dsa_ossl.c
index 03124c87a0..7c0a7802b0 100644
--- a/src/lib/libcrypto/dsa/dsa_ossl.c
+++ b/src/lib/libcrypto/dsa/dsa_ossl.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: dsa_ossl.c,v 1.22 2014/10/18 17:20:40 jsing Exp $ */
+/* $OpenBSD: dsa_ossl.c,v 1.23 2015/09/10 07:58:28 bcook Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -396,9 +396,7 @@ dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig, DSA *dsa)
         ret = BN_ucmp(&u1, sig->r) == 0;
 
 err:
-        /* XXX: surely this is wrong - if ret is 0, it just didn't verify;
-           there is no error in BN. Test should be ret == -1 (Ben) */
-        if (ret != 1)
+        if (ret < 0)
                 DSAerr(DSA_F_DSA_DO_VERIFY, ERR_R_BN_LIB);
         BN_CTX_free(ctx);
         BN_free(&u1);