release/src/router/openvpn/src/openvpn/session_id.c

   1 /*
   2  *  OpenVPN -- An application to securely tunnel IP networks
   3  *             over a single UDP port, with support for SSL/TLS-based
   4  *             session authentication and key exchange,
   5  *             packet encryption, packet authentication, and
   6  *             packet compression.
   7  *
   8  *  Copyright (C) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net>
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License version 2
  12  *  as published by the Free Software Foundation.
  13  *
  14  *  This program is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License
  20  *  along with this program (see the file COPYING included with this
  21  *  distribution); if not, write to the Free Software Foundation, Inc.,
  22  *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23  */
  24
  25 /*
  26  * Each session is identified by a random 8-byte session identifier.
  27  *
  28  * For efficiency, the session id is only transmitted over the control
  29  * channel (which only sees traffic occasionally when keys are being
  30  * negotiated).  The data channel sees a smaller version of the session-id --
  31  * it is called the key_id and is currently 2 bits long.
  32  */
  33
  34 #ifdef HAVE_CONFIG_H
  35 #include "config.h"
  36 #elif defined(_MSC_VER)
  37 #include "config-msvc.h"
  38 #endif
  39
  40 #include "syshead.h"
  41
  42 #if defined(ENABLE_CRYPTO) && defined(ENABLE_SSL)
  43
  44 #include "error.h"
  45 #include "common.h"
  46 #include "crypto.h"
  47 #include "session_id.h"
  48
  49 #include "memdbg.h"
  50
  51 const struct session_id x_session_id_zero;
  52
  53 void
  54 session_id_random (struct session_id *sid)
  55 {
  56   prng_bytes (sid->id, SID_SIZE);
  57 }
  58
  59 const char *
  60 session_id_print (const struct session_id *sid, struct gc_arena *gc)
  61 {
  62   return format_hex (sid->id, SID_SIZE, 0, gc);
  63 }
  64
  65 #else
  66 static void dummy(void) {}
  67 #endif /* ENABLE_CRYPTO && ENABLE_SSL*/