From f899583f948c04f1a5f8691f0123749789124c66 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Manuel=20P=C3=A9gouri=C3=A9-Gonnard?= <mpg@elzevir.fr>
Date: Wed, 10 Sep 2014 08:25:12 +0000
Subject: [PATCH] Prepare moving away from memmove() on incoming HS

---
 include/polarssl/ssl.h | 17 +++++++++++++++++
 library/ssl_cli.c      | 10 ++++++++++
 library/ssl_srv.c      |  4 ++++
 library/ssl_tls.c      | 34 +++++++---------------------------
 4 files changed, 38 insertions(+), 27 deletions(-)

diff --git a/include/polarssl/ssl.h b/include/polarssl/ssl.h
index 1cfb606c9..b5a033d8e 100644
--- a/include/polarssl/ssl.h
+++ b/include/polarssl/ssl.h
@@ -1974,6 +1974,23 @@ static inline int safer_memcmp( const void *a, const void *b, size_t n )
     return( diff );
 }
 
+/*
+ * Temporary function while transitionning away from memmove()
+ * on received DTLS handshake messages
+ */
+static inline void ssl_hs_rm_dtls_hdr( ssl_context *ssl )
+{
+#if defined(POLARSSL_SSL_PROTO_DTLS)
+    if( ssl->transport == SSL_TRANSPORT_DATAGRAM )
+    {
+        memmove( ssl->in_msg + 4, ssl->in_msg + 12, ssl->in_hslen - 12 );
+        ssl->in_hslen -= 8;
+    }
+#else
+    (void) ssl;
+#endif
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 12a8ff5dc..22787fd33 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -1069,6 +1069,8 @@ static int ssl_parse_server_hello( ssl_context *ssl )
         return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE );
     }
 
+    ssl_hs_rm_dtls_hdr( ssl );
+
 #if defined(POLARSSL_SSL_PROTO_DTLS)
     if( ssl->transport == SSL_TRANSPORT_DATAGRAM )
     {
@@ -1774,6 +1776,8 @@ static int ssl_parse_server_key_exchange( ssl_context *ssl )
         return( ret );
     }
 
+    ssl_hs_rm_dtls_hdr( ssl );
+
     if( ssl->in_msgtype != SSL_MSG_HANDSHAKE )
     {
         SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
@@ -2098,6 +2102,8 @@ static int ssl_parse_certificate_request( ssl_context *ssl )
             return( ret );
         }
 
+        ssl_hs_rm_dtls_hdr( ssl );
+
         if( ssl->in_msgtype != SSL_MSG_HANDSHAKE )
         {
             SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
@@ -2222,6 +2228,8 @@ static int ssl_parse_server_hello_done( ssl_context *ssl )
             return( ret );
         }
 
+        ssl_hs_rm_dtls_hdr( ssl );
+
         if( ssl->in_msgtype != SSL_MSG_HANDSHAKE )
         {
             SSL_DEBUG_MSG( 1, ( "bad server hello done message" ) );
@@ -2648,6 +2656,8 @@ static int ssl_parse_new_session_ticket( ssl_context *ssl )
         return( ret );
     }
 
+    ssl_hs_rm_dtls_hdr( ssl );
+
     if( ssl->in_msgtype != SSL_MSG_HANDSHAKE )
     {
         SSL_DEBUG_MSG( 1, ( "bad new session ticket message" ) );
diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index a1c2c4df5..81e3d0d0d 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -3018,6 +3018,8 @@ static int ssl_parse_client_key_exchange( ssl_context *ssl )
         return( ret );
     }
 
+    ssl_hs_rm_dtls_hdr( ssl );
+
     if( ssl->in_msgtype != SSL_MSG_HANDSHAKE )
     {
         SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
@@ -3310,6 +3312,8 @@ static int ssl_parse_certificate_verify( ssl_context *ssl )
         return( ret );
     }
 
+    ssl_hs_rm_dtls_hdr( ssl );
+
     ssl->state++;
 
     if( ssl->in_msgtype != SSL_MSG_HANDSHAKE )
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index b8946cda0..08b26b313 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -2408,22 +2408,6 @@ static int ssl_prepare_handshake_record( ssl_context *ssl )
     }
 #endif
 
-    /*
-     * For DTLS, we move data so that is looks like TLS handshake format to
-     * other functions.
-     * Except on server after the initial handshake (wait until after
-     * update_checksum() in ssl_parse_client_hello()).
-     */
-#if defined(POLARSSL_SSL_PROTO_DTLS)
-    if( ssl->transport == SSL_TRANSPORT_DATAGRAM &&
-        ! ( ssl->endpoint == SSL_IS_SERVER &&
-            ssl->state == SSL_HANDSHAKE_OVER ) )
-    {
-        memmove( ssl->in_msg + 4, ssl->in_msg + 12, ssl->in_hslen - 12 );
-        ssl->in_hslen -= 8;
-    }
-#endif /* POLARSSL_SSL_PROTO_DTLS */
-
     return( 0 );
 }
 
@@ -2625,16 +2609,8 @@ int ssl_read_record( ssl_context *ssl )
 
     SSL_DEBUG_MSG( 2, ( "=> read record" ) );
 
-    /*
-     * With DTLS, we cheated on in_hslen to make the handshake message look
-     * like TLS format, restore the truth now
-     */
-#if defined(POLARSSL_SSL_PROTO_DTLS)
-    if( ssl->in_hslen != 0 && ssl->transport == SSL_TRANSPORT_DATAGRAM )
-        ssl->in_hslen += 8;
-#endif
-
-    if( ssl->in_hslen != 0 && ssl->in_hslen < ssl->in_msglen )
+    /* Temporarily disabled */
+    if( ( 0 ) && ssl->in_hslen != 0 && ssl->in_hslen < ssl->in_msglen )
     {
         /*
          * Get next Handshake message in the current record
@@ -3001,6 +2977,8 @@ int ssl_parse_certificate( ssl_context *ssl )
         return( ret );
     }
 
+    ssl_hs_rm_dtls_hdr( ssl );
+
     ssl->state++;
 
 #if defined(POLARSSL_SSL_PROTO_SSL3)
@@ -3813,6 +3791,8 @@ int ssl_parse_finished( ssl_context *ssl )
         return( ret );
     }
 
+    ssl_hs_rm_dtls_hdr( ssl );
+
     if( ssl->in_msgtype != SSL_MSG_HANDSHAKE )
     {
         SSL_DEBUG_MSG( 1, ( "bad finished message" ) );
@@ -5041,7 +5021,7 @@ int ssl_read( ssl_context *ssl, unsigned char *buf, size_t len )
 
             if( ssl->endpoint == SSL_IS_CLIENT &&
                 ( ssl->in_msg[0] != SSL_HS_HELLO_REQUEST ||
-                  ssl->in_hslen != 4 ) )
+                  ssl->in_hslen != ssl_hs_hdr_len( ssl ) ) )
             {
                 SSL_DEBUG_MSG( 1, ( "handshake received (not HelloRequest)" ) );