upstream: change explicit_bzero();free() to freezero()

While freezero() returns early if the pointer is NULL the tests for
NULL in callers are left to avoid warnings about passing an
uninitialised size argument across a function boundry.

ok deraadt@ djm@

OpenBSD-Commit-ID: 2660fa334fcc7cd05ec74dd99cb036f9ade6384a

1 files changed, 2 insertions, 3 deletions

diff --git a/hmac.c b/hmac.c
index 32688876d..7b588019e 100644
--- a/hmac.c
+++ b/hmac.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: hmac.c,v 1.13 2019/09/06 04:53:27 djm Exp $ */
+/* $OpenBSD: hmac.c,v 1.14 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Copyright (c) 2014 Markus Friedl.  All rights reserved.
  *
@@ -131,8 +131,7 @@ ssh_hmac_free(struct ssh_hmac_ctx *ctx)
                         explicit_bzero(ctx->buf, ctx->buf_len);
                         free(ctx->buf);
                 }
-                explicit_bzero(ctx, sizeof(*ctx));
-                free(ctx);
+                freezero(ctx, sizeof(*ctx));
         }
 }