From: Jonathan Bastien-Filiatrault <joe@x2a.org>
Date: Tue, 28 Jul 2009 15:50:56 +0000 (-0400)
Subject: dtls: Add epoch and sequence number to DTLS packets.
X-Git-Tag: gnutls_2_99_0~252
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a311c2bc2b1a9c80b00671f4077265b8f1bd5be9;p=thirdparty%2Fgnutls.git

dtls: Add epoch and sequence number to DTLS packets.

Signed-off-by: Nikos Mavrogiannopoulos <nmav@gnutls.org>
---

diff --git a/lib/gnutls_cipher.c b/lib/gnutls_cipher.c
index f238fd4b5c..4ba03bfb39 100644
--- a/lib/gnutls_cipher.c
+++ b/lib/gnutls_cipher.c
@@ -40,6 +40,7 @@
 #include "gnutls_kx.h"
 #include "gnutls_record.h"
 #include "gnutls_constate.h"
+#include <gnutls_state.h>
 #include <random.h>
 
 static int _gnutls_compressed2ciphertext (gnutls_session_t session,
@@ -125,7 +126,11 @@ _gnutls_encrypt (gnutls_session_t session, const opaque * headers,
 
   /* copy the headers */
   memcpy (ciphertext, headers, headers_size);
-  _gnutls_write_uint16 (ret, &ciphertext[3]);
+  
+  if(_gnutls_is_dtls(session))
+    _gnutls_write_uint16 (ret, &ciphertext[11]);
+  else
+    _gnutls_write_uint16 (ret, &ciphertext[3]);
 
   return ret + headers_size;
 }
diff --git a/lib/gnutls_int.h b/lib/gnutls_int.h
index 2409776e8f..c9def019b5 100644
--- a/lib/gnutls_int.h
+++ b/lib/gnutls_int.h
@@ -151,8 +151,14 @@ typedef enum transport_t
 } transport_t;
 
 /* the maximum size of encrypted packets */
+#define IS_DTLS (session->internals.transport == GNUTLS_DGRAM)
+
 #define DEFAULT_MAX_RECORD_SIZE 16384
-#define RECORD_HEADER_SIZE 5
+#define TLS_RECORD_HEADER_SIZE 5
+#define DTLS_RECORD_HEADER_SIZE (TLS_RECORD_HEADER_SIZE+8)
+#define RECORD_HEADER_SIZE (IS_DTLS ? DTLS_RECORD_HEADER_SIZE : TLS_RECORD_HEADER_SIZE)
+#define MAX_RECORD_HEADER_SIZE DTLS_RECORD_HEADER_SIZE
+
 #define MAX_RECORD_SEND_SIZE (size_t)session->security_parameters.max_record_send_size
 #define MAX_RECORD_RECV_SIZE (size_t)session->security_parameters.max_record_recv_size
 #define MAX_PAD_SIZE 255
@@ -160,7 +166,10 @@ typedef enum transport_t
 #define MAX_RECORD_OVERHEAD (MAX_CIPHER_BLOCK_SIZE/*iv*/+MAX_PAD_SIZE+EXTRA_COMP_SIZE)
 #define MAX_RECV_SIZE (MAX_RECORD_OVERHEAD+MAX_RECORD_RECV_SIZE+RECORD_HEADER_SIZE)
 
-#define HANDSHAKE_HEADER_SIZE 4
+#define TLS_HANDSHAKE_HEADER_SIZE 4
+#define DTLS_HANDSHAKE_HEADER_SIZE (TLS_HANDSHAKE_HEADER_SIZE+8)
+#define HANDSHAKE_HEADER_SIZE (IS_DTLS ? DTLS_HANDSHAKE_HEADER_SIZE : TLS_HANDSHAKE_HEADER_SIZE)
+#define MAX_HANDSHAKE_HEADER_SIZE DTLS_HANDSHAKE_HEADER_SIZE
 
 /* the maximum size of the DTLS cookie */
 #define DTLS_MAX_COOKIE_SIZE 32
@@ -526,7 +535,7 @@ typedef struct
 
 typedef struct
 {
-  opaque header[HANDSHAKE_HEADER_SIZE];
+  opaque header[MAX_HANDSHAKE_HEADER_SIZE];
   /* this holds the number of bytes in the handshake_header[] */
   size_t header_size;
   /* this holds the length of the handshake packet */
diff --git a/lib/gnutls_record.c b/lib/gnutls_record.c
index 0219436ded..3186690c70 100644
--- a/lib/gnutls_record.c
+++ b/lib/gnutls_record.c
@@ -375,7 +375,8 @@ _gnutls_send_int (gnutls_session_t session, content_type_t type,
   size_t cipher_size;
   int retval, ret;
   int data2send_size;
-  uint8_t headers[5];
+  uint8_t headers[MAX_RECORD_HEADER_SIZE];
+  int header_size;
   const uint8_t *data = _data;
   record_parameters_st *record_params;
   record_state_st *record_state;
@@ -421,6 +422,9 @@ _gnutls_send_int (gnutls_session_t session, content_type_t type,
    */
   copy_record_version (session, htype, &headers[1]);
 
+  header_size = RECORD_HEADER_SIZE;
+  /* Adjust header length and add sequence for DTLS */
+    sequence_write(&record_state->sequence_number, &headers[3]);
 
   _gnutls_record_log
     ("REC[%p]: Sending Packet[%d] %s(%d) with length: %d\n", session,
@@ -459,7 +463,7 @@ _gnutls_send_int (gnutls_session_t session, content_type_t type,
         }
 
       cipher_size =
-        _gnutls_encrypt (session, headers, RECORD_HEADER_SIZE, data,
+        _gnutls_encrypt (session, headers, header_size, data,
                          data2send_size, _mbuffer_get_udata_ptr (bufel),
                          cipher_size, type,
                          (session->internals.priorities.no_padding ==
@@ -604,11 +608,12 @@ check_buffers (gnutls_session_t session, content_type_t type,
  */
 static int
 record_check_headers (gnutls_session_t session,
-                      uint8_t headers[RECORD_HEADER_SIZE],
+                      uint8_t headers[MAX_RECORD_HEADER_SIZE],
                       content_type_t type,
                       gnutls_handshake_description_t htype,
                       /*output */ content_type_t * recv_type,
-                      opaque version[2], uint16_t * length,
+                      opaque version[2], uint64* sequence,
+                      uint16_t * length,
                       uint16_t * header_size)
 {
 
@@ -642,6 +647,17 @@ record_check_headers (gnutls_session_t session,
                           session, *length);
 
     }
+  else if(_gnutls_is_dtls(session))
+    {
+      /* dtls version 1.0 */
+      *recv_type = headers[0];
+      version[0] = headers[1];
+      version[1] = headers[2];
+
+      sequence_read(sequence, &headers[3]);
+
+      *length = _gnutls_read_uint16 (&headers[11]);
+    }
   else
     {
       /* version 3.x 
@@ -904,6 +920,7 @@ _gnutls_recv_int (gnutls_session_t session, content_type_t type,
 {
   int decrypted_length;
   opaque version[2];
+  uint64 sequence;
   content_type_t recv_type;
   uint16_t length;
   uint8_t *ciphertext;
@@ -1000,7 +1017,7 @@ begin:
 
   if ((ret =
        record_check_headers (session, data_enc.data, type, htype, &recv_type,
-                             version, &length, &header_size)) < 0)
+                             version, &sequence, &length, &header_size)) < 0)
     {
       gnutls_assert ();
       return ret;