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, 5 insertions, 9 deletions

diff --git a/src/lib/libcrypto/bn/bn_lib.c b/src/lib/libcrypto/bn/bn_lib.c
index f2736e31c3..8aeeb5304f 100644
--- a/src/lib/libcrypto/bn/bn_lib.c
+++ b/src/lib/libcrypto/bn/bn_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: bn_lib.c,v 1.37 2017/01/29 17:49:22 beck Exp $ */
+/* $OpenBSD: bn_lib.c,v 1.38 2017/05/02 03:59:44 deraadt Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -220,10 +220,8 @@ BN_clear_free(BIGNUM *a)
         if (a == NULL)
                 return;
         bn_check_top(a);
-        if (a->d != NULL && !(BN_get_flags(a, BN_FLG_STATIC_DATA))) {
-                explicit_bzero(a->d, a->dmax * sizeof(a->d[0]));
-                free(a->d);
-        }
+        if (a->d != NULL && !(BN_get_flags(a, BN_FLG_STATIC_DATA)))
+                freezero(a->d, a->dmax * sizeof(a->d[0]));
         i = BN_get_flags(a, BN_FLG_MALLOCED);
         explicit_bzero(a, sizeof(BIGNUM));
         if (i)
@@ -393,10 +391,8 @@ bn_expand2(BIGNUM *b, int words)
                 BN_ULONG *a = bn_expand_internal(b, words);
                 if (!a)
                         return NULL;
-                if (b->d) {
-                        explicit_bzero(b->d, b->dmax * sizeof(b->d[0]));
-                        free(b->d);
-                }
+                if (b->d)
+                        freezero(b->d, b->dmax * sizeof(b->d[0]));
                 b->d = a;
                 b->dmax = words;
         }