From 990f9e428a7f2913c2d1ee073a2c54d8a819e161 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Manuel=20P=C3=A9gouri=C3=A9-Gonnard?= <mpg@elzevir.fr>
Date: Sat, 6 Sep 2014 12:27:02 +0200
Subject: [PATCH] Handle late handshake messages gracefully

---
 library/ssl_tls.c | 21 ++++++++++++++++++++-
 tests/ssl-opt.sh  | 21 ++++++++++++++++++---
 2 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 71d07b5a9..31413e4d9 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -4970,6 +4970,25 @@ int ssl_read( ssl_context *ssl, unsigned char *buf, size_t len )
                   ssl->in_hslen != 4 ) )
             {
                 SSL_DEBUG_MSG( 1, ( "handshake received (not HelloRequest)" ) );
+
+                /* With DTLS, drop the packet (probably from last handshake) */
+#if defined(POLARSSL_SSL_PROTO_DTLS)
+                if( ssl->transport == SSL_TRANSPORT_DATAGRAM )
+                    return( POLARSSL_ERR_NET_WANT_READ );
+#endif
+                return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE );
+            }
+
+            if( ssl->endpoint == SSL_IS_SERVER &&
+                ssl->in_msg[0] != SSL_HS_CLIENT_HELLO )
+            {
+                SSL_DEBUG_MSG( 1, ( "handshake received (not ClientHello)" ) );
+
+                /* With DTLS, drop the packet (probably from last handshake) */
+#if defined(POLARSSL_SSL_PROTO_DTLS)
+                if( ssl->transport == SSL_TRANSPORT_DATAGRAM )
+                    return( POLARSSL_ERR_NET_WANT_READ );
+#endif
                 return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE );
             }
 
@@ -4978,7 +4997,7 @@ int ssl_read( ssl_context *ssl, unsigned char *buf, size_t len )
                   ssl->allow_legacy_renegotiation ==
                                                 SSL_LEGACY_NO_RENEGOTIATION ) )
             {
-                SSL_DEBUG_MSG( 3, ( "ignoring renegotiation, sending alert" ) );
+                SSL_DEBUG_MSG( 3, ( "refusing renegotiation, sending alert" ) );
 
 #if defined(POLARSSL_SSL_PROTO_SSL3)
                 if( ssl->minor_ver == SSL_MINOR_VERSION_0 )
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 64d39734e..c7758b883 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -2097,13 +2097,28 @@ run_test    "DTLS reassembly: fragmentation, nbio (openssl server)" \
             -c "found fragmented DTLS handshake message" \
             -C "error"
 
-# Temporary test for ability to use the UDP proxy
+# Tests with UDP proxy emulating unreliable transport
 
-run_test    "DTLS proxy usability test" \
+run_test    "DTLS proxy: reference" \
             -p "$P_PXY" \
             "$P_SRV dtls=1" \
             "$P_CLI dtls=1" \
-            0
+            0 \
+            -c "HTTP/1.0 200 OK"
+
+run_test    "DTLS proxy: some duplication" \
+            -p "$P_PXY duplicate=3" \
+            "$P_SRV dtls=1" \
+            "$P_CLI dtls=1" \
+            0 \
+            -c "HTTP/1.0 200 OK"
+
+run_test    "DTLS proxy: lots of duplication" \
+            -p "$P_PXY duplicate=1" \
+            "$P_SRV dtls=1" \
+            "$P_CLI dtls=1" \
+            0 \
+            -c "HTTP/1.0 200 OK"
 
 # Final report