/*
 *  anytun
 *
 *  The secure anycast tunneling protocol (satp) defines a protocol used
 *  for communication between any combination of unicast and anycast
 *  tunnel endpoints.  It has less protocol overhead than IPSec in Tunnel
 *  mode and allows tunneling of every ETHER TYPE protocol (e.g.
 *  ethernet, ip, arp ...). satp directly includes cryptography and
 *  message authentication based on the methodes used by SRTP.  It is
 *  intended to deliver a generic, scaleable and secure solution for
 *  tunneling and relaying of packets of any protocol.
 *
 *
 *  Copyright (C) 2007 anytun.org <satp@wirdorange.org>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program (see the file COPYING included with this
 *  distribution); if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "authAlgo.h"

extern "C" {
#include <gcrypt.h>
}


AuthTag NullAuthAlgo::calc(const Buffer& buf)
{
  return AuthTag(0);
}


// HMAC_SHA1
AuthTag HmacAuthAlgo::calc(const Buffer& buf)
{
  gcry_error_t err;
  gcry_md_hd_t ctx;
  Buffer hmac;  //80bit

  err = gcry_md_open( &ctx, GCRY_MD_SHA1, GCRY_MD_FLAG_HMAC );
  //gcry_md_setkey( ctx, key, keylen );
  gcry_md_write( ctx, static_cast<Buffer>(buf).getBuf(), buf.getLength() );
  gcry_md_final( ctx );
  hmac = Buffer(gcry_md_read( ctx, 0 ), 10);
  gcry_md_close( ctx );
  return hmac;
}