From: Dr. Stephen Henson <steve@openssl.org>
Date: Wed, 4 Jan 2012 15:27:54 +0000 (+0000)
Subject: Only allow one SGC handshake restart for SSL/TLS. (CVE-2011-4619)
X-Git-Tag: OpenSSL_1_0_0f~7
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=9004c53107aee0e2afae8544bd10a2e8bc621eeb;p=oweals%2Fopenssl.git

Only allow one SGC handshake restart for SSL/TLS. (CVE-2011-4619)
---

diff --git a/CHANGES b/CHANGES
index 0fc2b70b25..193b5b5d47 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,9 @@
 
  Changes between 1.0.0e and 1.0.0f [xx XXX xxxx]
 
+  *) Only allow one SGC handshake restart for SSL/TLS. (CVE-2011-4619)
+     [Adam Langley (Google)]
+
   *) Check parameters are not NULL in GOST ENGINE. (CVE-2012-0027)
      [Andrey Kulikov <amdeich@gmail.com>]
 
diff --git a/ssl/s3_srvr.c b/ssl/s3_srvr.c
index 7b00ae1126..d734c359fb 100644
--- a/ssl/s3_srvr.c
+++ b/ssl/s3_srvr.c
@@ -258,6 +258,7 @@ int ssl3_accept(SSL *s)
 				}
 
 			s->init_num=0;
+			s->s3->flags &= ~SSL3_FLAGS_SGC_RESTART_DONE;
 
 			if (s->state != SSL_ST_RENEGOTIATE)
 				{
@@ -755,6 +756,14 @@ int ssl3_check_client_hello(SSL *s)
 	int ok;
 	long n;
 
+	/* We only allow the client to restart the handshake once per
+	 * negotiation. */
+	if (s->s3->flags & SSL3_FLAGS_SGC_RESTART_DONE)
+		{
+		SSLerr(SSL_F_SSL3_CHECK_CLIENT_HELLO, SSL_R_MULTIPLE_SGC_RESTARTS);
+		return -1;
+		}
+
 	/* this function is called when we really expect a Certificate message,
 	 * so permit appropriate message length */
 	n=s->method->ssl_get_message(s,
@@ -783,6 +792,7 @@ int ssl3_check_client_hello(SSL *s)
 			s->s3->tmp.ecdh = NULL;
 			}
 #endif
+		s->s3->flags |= SSL3_FLAGS_SGC_RESTART_DONE;
 		return 2;
 		}
 	return 1;
diff --git a/ssl/ssl.h b/ssl/ssl.h
index e4c3f65010..8f922eea72 100644
--- a/ssl/ssl.h
+++ b/ssl/ssl.h
@@ -1882,6 +1882,7 @@ void ERR_load_SSL_strings(void);
 #define SSL_F_SSL3_CALLBACK_CTRL			 233
 #define SSL_F_SSL3_CHANGE_CIPHER_STATE			 129
 #define SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM		 130
+#define SSL_F_SSL3_CHECK_CLIENT_HELLO			 304
 #define SSL_F_SSL3_CLIENT_HELLO				 131
 #define SSL_F_SSL3_CONNECT				 132
 #define SSL_F_SSL3_CTRL					 213
@@ -2139,6 +2140,7 @@ void ERR_load_SSL_strings(void);
 #define SSL_R_MISSING_TMP_RSA_KEY			 172
 #define SSL_R_MISSING_TMP_RSA_PKEY			 173
 #define SSL_R_MISSING_VERIFY_MESSAGE			 174
+#define SSL_R_MULTIPLE_SGC_RESTARTS			 346
 #define SSL_R_NON_SSLV2_INITIAL_PACKET			 175
 #define SSL_R_NO_CERTIFICATES_RETURNED			 176
 #define SSL_R_NO_CERTIFICATE_ASSIGNED			 177
diff --git a/ssl/ssl_err.c b/ssl/ssl_err.c
index 0eed464749..e9be77109f 100644
--- a/ssl/ssl_err.c
+++ b/ssl/ssl_err.c
@@ -1,6 +1,6 @@
 /* ssl/ssl_err.c */
 /* ====================================================================
- * Copyright (c) 1999-2009 The OpenSSL Project.  All rights reserved.
+ * Copyright (c) 1999-2011 The OpenSSL Project.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -137,6 +137,7 @@ static ERR_STRING_DATA SSL_str_functs[]=
 {ERR_FUNC(SSL_F_SSL3_CALLBACK_CTRL),	"SSL3_CALLBACK_CTRL"},
 {ERR_FUNC(SSL_F_SSL3_CHANGE_CIPHER_STATE),	"SSL3_CHANGE_CIPHER_STATE"},
 {ERR_FUNC(SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM),	"SSL3_CHECK_CERT_AND_ALGORITHM"},
+{ERR_FUNC(SSL_F_SSL3_CHECK_CLIENT_HELLO),	"SSL3_CHECK_CLIENT_HELLO"},
 {ERR_FUNC(SSL_F_SSL3_CLIENT_HELLO),	"SSL3_CLIENT_HELLO"},
 {ERR_FUNC(SSL_F_SSL3_CONNECT),	"SSL3_CONNECT"},
 {ERR_FUNC(SSL_F_SSL3_CTRL),	"SSL3_CTRL"},
@@ -397,6 +398,7 @@ static ERR_STRING_DATA SSL_str_reasons[]=
 {ERR_REASON(SSL_R_MISSING_TMP_RSA_KEY)   ,"missing tmp rsa key"},
 {ERR_REASON(SSL_R_MISSING_TMP_RSA_PKEY)  ,"missing tmp rsa pkey"},
 {ERR_REASON(SSL_R_MISSING_VERIFY_MESSAGE),"missing verify message"},
+{ERR_REASON(SSL_R_MULTIPLE_SGC_RESTARTS) ,"multiple sgc restarts"},
 {ERR_REASON(SSL_R_NON_SSLV2_INITIAL_PACKET),"non sslv2 initial packet"},
 {ERR_REASON(SSL_R_NO_CERTIFICATES_RETURNED),"no certificates returned"},
 {ERR_REASON(SSL_R_NO_CERTIFICATE_ASSIGNED),"no certificate assigned"},