use freezero() instead of memset/explicit_bzero + free. Substantially

reduces conditional logic (-218, +82).

MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH cache alignment calculation bn/bn_exp.c
wasn'tt quite right.  Two other tricky bits with ASN1_STRING_FLAG_NDEF and
BN_FLG_STATIC_DATA where the condition cannot be collapsed completely.

Passes regress.  ok beck

1 files changed, 2 insertions, 5 deletions

diff --git a/src/lib/libcrypto/dsa/dsa_asn1.c b/src/lib/libcrypto/dsa/dsa_asn1.c
index d7b77470bd..f7dfaf1d9c 100644
--- a/src/lib/libcrypto/dsa/dsa_asn1.c
+++ b/src/lib/libcrypto/dsa/dsa_asn1.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: dsa_asn1.c,v 1.19 2017/01/29 17:49:22 beck Exp $ */
+/* $OpenBSD: dsa_asn1.c,v 1.20 2017/05/02 03:59:44 deraadt Exp $ */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project 2000.
  */
@@ -454,10 +454,7 @@ DSA_verify(int type, const unsigned char *dgst, int dgst_len,
                 goto err;
         ret = DSA_do_verify(dgst, dgst_len, s, dsa);
 err:
-        if (derlen > 0) {
-                explicit_bzero(der, derlen);
-                free(der);
-        }
+        freezero(der, derlen);
         DSA_SIG_free(s);
         return ret;
 }