From 200c91bcd0cbd0e0be44ab09d69d30844bd3c307 Mon Sep 17 00:00:00 2001
From: jasper <>
Date: Wed, 15 Dec 2010 09:43:55 +0000
Subject: Security fix for CVE-2010-4180 as mentioned in
 http://www.openssl.org/news/secadv_20101202.txt. where clients could modify
 the stored session cache ciphersuite and in some cases even downgrade the
 suite to weaker ones.

This code is not enabled by default.

ok djm@
---
 src/lib/libssl/src/ssl/s3_clnt.c | 3 +++
 src/lib/libssl/src/ssl/s3_srvr.c | 5 +++++
 2 files changed, 8 insertions(+)

(limited to 'src')

diff --git a/src/lib/libssl/src/ssl/s3_clnt.c b/src/lib/libssl/src/ssl/s3_clnt.c
index 50308487aa..0ca1978c8b 100644
--- a/src/lib/libssl/src/ssl/s3_clnt.c
+++ b/src/lib/libssl/src/ssl/s3_clnt.c
@@ -816,8 +816,11 @@ int ssl3_get_server_hello(SSL *s)
 		s->session->cipher_id = s->session->cipher->id;
 	if (s->hit && (s->session->cipher_id != c->id))
 		{
+/* Workaround is now obsolete */
+#if 0
 		if (!(s->options &
 			SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG))
+#endif
 			{
 			al=SSL_AD_ILLEGAL_PARAMETER;
 			SSLerr(SSL_F_SSL3_GET_SERVER_HELLO,SSL_R_OLD_SESSION_CIPHER_NOT_RETURNED);
diff --git a/src/lib/libssl/src/ssl/s3_srvr.c b/src/lib/libssl/src/ssl/s3_srvr.c
index 79f3706c31..4215eeeeb2 100644
--- a/src/lib/libssl/src/ssl/s3_srvr.c
+++ b/src/lib/libssl/src/ssl/s3_srvr.c
@@ -910,6 +910,10 @@ int ssl3_get_client_hello(SSL *s)
 				break;
 				}
 			}
+/* Disabled because it can be used in a ciphersuite downgrade
+ * attack: CVE-2010-4180.
+ */
+#if 0
 		if (j == 0 && (s->options & SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG) && (sk_SSL_CIPHER_num(ciphers) == 1))
 			{
 			/* Special case as client bug workaround: the previously used cipher may
@@ -924,6 +928,7 @@ int ssl3_get_client_hello(SSL *s)
 				j = 1;
 				}
 			}
+#endif
 		if (j == 0)
 			{
 			/* we need to have the cipher in the cipher
-- 
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