From: Matt Caswell <matt@openssl.org>
Date: Tue, 9 Sep 2014 20:50:06 +0000 (-0400)
Subject: RT3192: spurious error in DSA verify
X-Git-Tag: OpenSSL_1_0_2-beta3~36
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=f33ce36aff4c0957dad2427814bd944d5c5d93c3;p=openssl

RT3192: spurious error in DSA verify

This is funny; Ben commented in the source, Matt opend a ticket,
and Rich is doing the submit.  Need more code-review? :)

Reviewed-by: Dr. Stephen Henson <steve@openssl.org>
(cherry picked from commit eb63bce040d1cc6147d256f516b59552c018e29b)
---

diff --git a/crypto/dsa/dsa_ossl.c b/crypto/dsa/dsa_ossl.c
index b3d78e524c..0c517c3b5d 100644
--- a/crypto/dsa/dsa_ossl.c
+++ b/crypto/dsa/dsa_ossl.c
@@ -387,9 +387,7 @@ static int dsa_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
 	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) DSAerr(DSA_F_DSA_DO_VERIFY,ERR_R_BN_LIB);
+	if (ret < 0) DSAerr(DSA_F_DSA_DO_VERIFY,ERR_R_BN_LIB);
 	if (ctx != NULL) BN_CTX_free(ctx);
 	BN_free(&u1);
 	BN_free(&u2);