From a82eab72890818aac5952c21256f03611957884e Mon Sep 17 00:00:00 2001
From: delphij <delphij@ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f>
Date: Sat, 30 Jan 2016 06:12:03 +0000
Subject: [PATCH] Fix OpenSSL SSLv2 ciphersuite downgrade vulnerability.

Security:	CVE-2015-3197
Security:	FreeBSD-SA-16:11.openssl
Approved by:	so


git-svn-id: svn://svn.freebsd.org/base/releng/10.1@295061 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
---
 UPDATING                     |  4 ++++
 crypto/openssl/ssl/s2_srvr.c | 17 ++++++++++++++---
 sys/conf/newvers.sh          |  2 +-
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/UPDATING b/UPDATING
index 79e820d1a..ca23b6666 100644
--- a/UPDATING
+++ b/UPDATING
@@ -16,6 +16,10 @@ from older versions of FreeBSD, try WITHOUT_CLANG to bootstrap to the tip of
 stable/10, and then rebuild without this option. The bootstrap process from
 older version of current is a bit fragile.
 
+20160130	p29	FreeBSD-SA-16:11.openssl
+
+	Fix OpenSSL SSLv2 ciphersuite downgrade vulnerability. [SA-16:11]
+
 20160127	p28	FreeBSD-SA-16:09.ntp
 			FreeBSD-SA-16:10.linux
 
diff --git a/crypto/openssl/ssl/s2_srvr.c b/crypto/openssl/ssl/s2_srvr.c
index 18e28134d..d645e02a6 100644
--- a/crypto/openssl/ssl/s2_srvr.c
+++ b/crypto/openssl/ssl/s2_srvr.c
@@ -400,7 +400,7 @@ static int get_client_master_key(SSL *s)
 			}
 
 		cp=ssl2_get_cipher_by_char(p);
-		if (cp == NULL)
+		if (cp == NULL || sk_SSL_CIPHER_find(s->session->ciphers, cp) < 0)
 			{
 			ssl2_return_error(s,SSL2_PE_NO_CIPHER);
 			SSLerr(SSL_F_GET_CLIENT_MASTER_KEY, SSL_R_NO_CIPHER_MATCH);
@@ -698,9 +698,12 @@ static int get_client_hello(SSL *s)
 		    prio = cs;
 		    allow = cl;
 		    }
-		for (z=0; z<sk_SSL_CIPHER_num(prio); z++)
+		/* Generate list of SSLv2 ciphers shared between client and server */
+		for (z = 0; z < sk_SSL_CIPHER_num(prio); z++)
 			{
-			if (sk_SSL_CIPHER_find(allow,sk_SSL_CIPHER_value(prio,z)) < 0)
+			const SSL_CIPHER *cp = sk_SSL_CIPHER_value(prio, z);
+			if ((cp->algorithm_ssl & SSL_SSLV2) == 0 ||
+			    sk_SSL_CIPHER_find(allow, cp) < 0)
 				{
 				(void)sk_SSL_CIPHER_delete(prio,z);
 				z--;
@@ -711,6 +714,14 @@ static int get_client_hello(SSL *s)
 		    sk_SSL_CIPHER_free(s->session->ciphers);
 		    s->session->ciphers = prio;
 		    }
+
+		/* Make sure we have at least one cipher in common */
+		if (sk_SSL_CIPHER_num(s->session->ciphers) == 0)
+			{
+			ssl2_return_error(s, SSL2_PE_NO_CIPHER);
+			SSLerr(SSL_F_GET_CLIENT_HELLO, SSL_R_NO_CIPHER_MATCH);
+			return -1;
+			}
 		/* s->session->ciphers should now have a list of
 		 * ciphers that are on both the client and server.
 		 * This list is ordered by the order the client sent
diff --git a/sys/conf/newvers.sh b/sys/conf/newvers.sh
index e496f8fdd..1f2c412f8 100644
--- a/sys/conf/newvers.sh
+++ b/sys/conf/newvers.sh
@@ -32,7 +32,7 @@
 
 TYPE="FreeBSD"
 REVISION="10.1"
-BRANCH="RELEASE-p28"
+BRANCH="RELEASE-p29"
 if [ "X${BRANCH_OVERRIDE}" != "X" ]; then
 	BRANCH=${BRANCH_OVERRIDE}
 fi
-- 
2.42.0