Avoid memset() before memcpy() for CBB_add_bytes().

CBB_add_bytes() calls CBB_add_space(), which now explicitly zeros memory
to avoid information leaks. However CBB_add_bytes() calls memcpy() for the
same memory region, so the memset() is unnecessary. Avoid this by inlining
part of CBB_add_space() rather than calling it directly.

ok beck@ tb@

1 files changed, 2 insertions, 2 deletions

diff --git a/src/lib/libssl/bs_cbb.c b/src/lib/libssl/bs_cbb.c
index d11da853cd..e734dd68fc 100644
--- a/src/lib/libssl/bs_cbb.c
+++ b/src/lib/libssl/bs_cbb.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: bs_cbb.c,v 1.22 2020/03/13 15:54:34 jsing Exp $       */
+/*      $OpenBSD: bs_cbb.c,v 1.23 2020/09/16 05:52:04 jsing Exp $       */
 /*
  * Copyright (c) 2014, Google Inc.
  *
@@ -361,7 +361,7 @@ CBB_add_bytes(CBB *cbb, const uint8_t *data, size_t len)
 {
         uint8_t *dest;
 
-        if (!CBB_add_space(cbb, &dest, len))
+        if (!CBB_flush(cbb) || !cbb_buffer_add(cbb->base, &dest, len))
                 return 0;
 
         memcpy(dest, data, len);