Added a magic number in front session DB data.

3 files changed, 19 insertions, 2 deletions

diff --git a/lib/gnutls_db.c b/lib/gnutls_db.c
index 572e8204b2..1ef7e73650 100644
--- a/lib/gnutls_db.c
+++ b/lib/gnutls_db.c
@@ -156,16 +156,24 @@ gnutls_db_check_entry (gnutls_session_t session, gnutls_datum_t session_entry)
  * This function returns the time that this entry was active.
  * It can be used for database entry expiration.
  *
+ * Returns: The time this entry was created, or zero on error.
  **/
 time_t
 gnutls_db_check_entry_time (gnutls_datum_t *entry)
 {
 uint32_t t;
+uint32_t magic;
 
-  if (entry->size < 4)
+  if (entry->size < 8)
     return gnutls_assert_val(0);
   
-  memcpy(&t, entry->data, 4);
+  memcpy(&magic, entry->data, 4);
+  
+  if (magic != PACKED_SESSION_MAGIC)
+    return gnutls_assert_val(0);
+  
+  memcpy(&t, &entry->data[4], 4);
+
   return t;
 }
 
diff --git a/lib/gnutls_db.h b/lib/gnutls_db.h
index 98302417d8..ca698e4a2d 100644
--- a/lib/gnutls_db.h
+++ b/lib/gnutls_db.h
@@ -24,3 +24,5 @@ int _gnutls_server_register_current_session (gnutls_session_t session);
 int _gnutls_server_restore_session (gnutls_session_t session,
                                     uint8_t * session_id,
                                     int session_id_size);
+
+#define PACKED_SESSION_MAGIC 0xfadebade
diff --git a/lib/gnutls_session_pack.c b/lib/gnutls_session_pack.c
index e221c40867..b7a5f8b3b6 100644
--- a/lib/gnutls_session_pack.c
+++ b/lib/gnutls_session_pack.c
@@ -42,6 +42,7 @@
 #include <gnutls_constate.h>
 #include <algorithms.h>
 #include <gnutls_state.h>
+#include <gnutls_db.h>
 
 static int pack_certificate_auth_info (gnutls_session_t,
                                        gnutls_buffer_st * packed_session);
@@ -97,6 +98,7 @@ _gnutls_session_pack (gnutls_session_t session,
   id = gnutls_auth_get_type (session);
 
   /* first is the timestamp */
+  BUFFER_APPEND_NUM(&sb, PACKED_SESSION_MAGIC);
   BUFFER_APPEND_NUM(&sb, session->security_parameters.timestamp);
   BUFFER_APPEND (&sb, &id, 1);
 
@@ -178,6 +180,7 @@ _gnutls_session_unpack (gnutls_session_t session,
 {
   int ret;
   gnutls_buffer_st sb;
+  uint32_t magic;
   uint8_t id;
 
   _gnutls_buffer_init (&sb);
@@ -203,6 +206,10 @@ _gnutls_session_unpack (gnutls_session_t session,
     }
 
   /* the timestamp is first */
+  BUFFER_POP_NUM (&sb, magic);
+  if (magic != PACKED_SESSION_MAGIC)
+    return gnutls_assert_val(GNUTLS_E_DB_ERROR);
+
   BUFFER_POP_NUM (&sb, session->internals.resumed_security_parameters.timestamp);
   BUFFER_POP (&sb, &id, 1);