commit 767c69561bbda2cbc1f3e74fb7b8f38a89843578
author Manuel Pégourié-Gonnard <mpg@elzevir.fr> Sat Sep 20 10:04:00 2014 +0200
committer Paul Bakker <p.j.bakker@polarssl.org> Tue Oct 21 16:32:29 2014 +0200
tree 6dde0c70abf35b5854849ba572e94f7bd44cc9b7
parent 7cf3518284f5a3bd58949ddfde4ea707738e4718

Drop out-of-sequence ChangeCipherSpec messages

library/ssl_tls.c

diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 5472b4d..6c89fbe 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -2637,7 +2637,7 @@
             }
             else
             {
-                SSL_DEBUG_MSG( 2, ( "dropping out-of-order message: "
+                SSL_DEBUG_MSG( 2, ( "dropping out-of-sequence message: "
                                     "message_seq = %d, expected = %d",
                                     recv_msg_seq,
                                     ssl->handshake->in_msg_seq ) );
@@ -3017,6 +3017,20 @@
         }
     }
 
+#if defined(POLARSSL_SSL_PROTO_DTLS)
+    if( ssl->transport == SSL_TRANSPORT_DATAGRAM )
+    {
+        /* Drop unexpected ChangeCipherSpec messages */
+        if( ssl->in_msgtype == SSL_MSG_CHANGE_CIPHER_SPEC &&
+            ssl->state != SSL_CLIENT_CHANGE_CIPHER_SPEC &&
+            ssl->state != SSL_SERVER_CHANGE_CIPHER_SPEC )
+        {
+            SSL_DEBUG_MSG( 2, ( "dropping unexpected ChangeCipherSpec" ) );
+            return( POLARSSL_ERR_NET_WANT_READ );
+        }
+    }
+#endif
+
     SSL_DEBUG_MSG( 2, ( "<= read record" ) );
 
     return( 0 );