From 53cf491d8405e23b0f0b5b740684df633ecec3b9 Mon Sep 17 00:00:00 2001
From: jsing <>
Date: Thu, 22 Sep 2016 12:33:50 +0000
Subject: Avoid unbounded memory growth, which can be triggered by a client
 repeatedly renegotiating and sending OCSP Status Request TLS extensions.

Fix based on OpenSSL.
---
 src/lib/libssl/t1_lib.c | 29 ++++++++++++++++++++---------
 1 file changed, 20 insertions(+), 9 deletions(-)

(limited to 'src/lib')

diff --git a/src/lib/libssl/t1_lib.c b/src/lib/libssl/t1_lib.c
index 6853bc210e..3f66e2e6d0 100644
--- a/src/lib/libssl/t1_lib.c
+++ b/src/lib/libssl/t1_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: t1_lib.c,v 1.89 2016/09/22 06:57:40 guenther Exp $ */
+/* $OpenBSD: t1_lib.c,v 1.90 2016/09/22 12:33:50 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1444,10 +1444,28 @@ ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d,
 				/* Read in responder_id_list */
 				n2s(data, dsize);
 				size -= 2;
-				if (dsize > size  ) {
+				if (dsize > size) {
 					*al = SSL_AD_DECODE_ERROR;
 					return 0;
 				}
+
+				/*
+				 * We remove any OCSP_RESPIDs from a
+				 * previous handshake to prevent
+				 * unbounded memory growth.
+				 */
+				sk_OCSP_RESPID_pop_free(s->tlsext_ocsp_ids,
+				    OCSP_RESPID_free);
+				s->tlsext_ocsp_ids = NULL;
+				if (dsize > 0) {
+					s->tlsext_ocsp_ids =
+					    sk_OCSP_RESPID_new_null();
+					if (s->tlsext_ocsp_ids == NULL) {
+						*al = SSL_AD_INTERNAL_ERROR;
+						return 0;
+					}
+				}
+
 				while (dsize > 0) {
 					OCSP_RESPID *id;
 					int idsize;
@@ -1475,13 +1493,6 @@ ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d,
 						*al = SSL_AD_DECODE_ERROR;
 						return 0;
 					}
-					if (!s->tlsext_ocsp_ids &&
-					    !(s->tlsext_ocsp_ids =
-					    sk_OCSP_RESPID_new_null())) {
-						OCSP_RESPID_free(id);
-						*al = SSL_AD_INTERNAL_ERROR;
-						return 0;
-					}
 					if (!sk_OCSP_RESPID_push(
 					    s->tlsext_ocsp_ids, id)) {
 						OCSP_RESPID_free(id);
-- 
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