From 764541b0cbbef5bbe8943ea3da53ba158801937c Mon Sep 17 00:00:00 2001
From: jsing <>
Date: Sat, 9 Dec 2017 13:43:25 +0000
Subject: MFC: Correct TLS extensions handling when no extensions are present.

If no TLS extensions are present in a client hello or server hello, omit
the entire extensions block, rather than including it with a length of
zero.

ok beck@ inoguchi@

Thanks to Eric Elena <eric at voguemerry dot com> for providing packet
captures and testing the fix.
---
 src/lib/libssl/bs_cbb.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

(limited to 'src/lib/libssl/bs_cbb.c')

diff --git a/src/lib/libssl/bs_cbb.c b/src/lib/libssl/bs_cbb.c
index 9de75fbb02..1c02eaf0be 100644
--- a/src/lib/libssl/bs_cbb.c
+++ b/src/lib/libssl/bs_cbb.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bs_cbb.c,v 1.17 2017/08/12 02:50:05 jsing Exp $	*/
+/*	$OpenBSD: bs_cbb.c,v 1.17.4.1 2017/12/09 13:43:25 jsing Exp $	*/
 /*
  * Copyright (c) 2014, Google Inc.
  *
@@ -271,6 +271,20 @@ CBB_flush(CBB *cbb)
 	return 1;
 }
 
+void
+CBB_discard_child(CBB *cbb)
+{
+	if (cbb->child == NULL)
+		return;
+
+	cbb->base->len = cbb->offset;
+	
+	cbb->child->base = NULL;
+	cbb->child = NULL;
+	cbb->pending_len_len = 0;
+	cbb->pending_is_asn1 = 0;
+	cbb->offset = 0;
+}
 
 static int
 cbb_add_length_prefixed(CBB *cbb, CBB *out_contents, size_t len_len)
-- 
cgit v1.2.3-55-g6feb