From 0aaefcebc0658b081f440ccede43504532d90c8c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Manuel=20P=C3=A9gouri=C3=A9-Gonnard?= <mpg2@elzevir.fr>
Date: Tue, 27 Oct 2015 13:42:11 +0100
Subject: [PATCH] Actually ignore most non-fatal alerts

fixes #308
---
 ChangeLog         |  6 ++++++
 library/ssl_tls.c | 26 +++++++++++++++++++++++++-
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 3ca926813..1c132ab51 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 mbed TLS ChangeLog (Sorted per branch, date)
 
+= mbed TLS 1.3.15 released 2015-10-xx
+
+Bugfix
+   * Fix bug causing some handshakes to fail due to some non-fatal alerts not
+     begin properly ignored. Found by mancha and Kasom Koht-arsa, #308
+
 = mbed TLS 1.3.14 released 2015-10-06
 
 Security
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 7fc9d9908..44e558257 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -2211,6 +2211,7 @@ int ssl_read_record( ssl_context *ssl )
     /*
      * Read the record header and validate it
      */
+read_record_header:
     if( ( ret = ssl_fetch_input( ssl, 5 ) ) != 0 )
     {
         SSL_DEBUG_RET( 1, "ssl_fetch_input", ret );
@@ -2408,7 +2409,7 @@ int ssl_read_record( ssl_context *ssl )
                        ssl->in_msg[0], ssl->in_msg[1] ) );
 
         /*
-         * Ignore non-fatal alerts, except close_notify
+         * Ignore non-fatal alerts, except close_notify and no_renego
          */
         if( ssl->in_msg[0] == SSL_ALERT_LEVEL_FATAL )
         {
@@ -2423,6 +2424,29 @@ int ssl_read_record( ssl_context *ssl )
             SSL_DEBUG_MSG( 2, ( "is a close notify message" ) );
             return( POLARSSL_ERR_SSL_PEER_CLOSE_NOTIFY );
         }
+
+        if( ssl->in_msg[0] == SSL_ALERT_LEVEL_WARNING &&
+            ssl->in_msg[1] == SSL_ALERT_MSG_NO_RENEGOTIATION )
+        {
+            SSL_DEBUG_MSG( 2, ( "is a no_renegotiation" ) );
+            /* Will be handled when trying to parse ServerHello */
+            ssl->in_left = 0;
+            return( 0 );
+        }
+
+        if( ssl->minor_ver == SSL_MINOR_VERSION_0 &&
+            ssl->endpoint == SSL_IS_SERVER &&
+            ssl->in_msg[0] == SSL_ALERT_LEVEL_WARNING &&
+            ssl->in_msg[1] == SSL_ALERT_MSG_NO_CERT )
+        {
+            SSL_DEBUG_MSG( 2, ( "is a SSLv3 no_cert" ) );
+            /* Will be handled in ssl_parse_certificate() */
+            ssl->in_left = 0;
+            return( 0 );
+        }
+
+        /* Silently discard: fetch new message */
+        goto read_record_header;
     }
 
     ssl->in_left = 0;