src/mpi.h

   1 /*
   2  *  anytun
   3  *
   4  *  The secure anycast tunneling protocol (satp) defines a protocol used
   5  *  for communication between any combination of unicast and anycast
   6  *  tunnel endpoints.  It has less protocol overhead than IPSec in Tunnel
   7  *  mode and allows tunneling of every ETHER TYPE protocol (e.g.
   8  *  ethernet, ip, arp ...). satp directly includes cryptography and
   9  *  message authentication based on the methodes used by SRTP.  It is
  10  *  intended to deliver a generic, scaleable and secure solution for
  11  *  tunneling and relaying of packets of any protocol.
  12  *
  13  *
  14  *  Copyright (C) 2007-2008 Othmar Gsenger, Erwin Nindl,
  15  *                          Christian Pointner <satp@wirdorange.org>
  16  *
  17  *  This file is part of Anytun.
  18  *
  19  *  Anytun is free software: you can redistribute it and/or modify
  20  *  it under the terms of the GNU General Public License version 3 as
  21  *  published by the Free Software Foundation.
  22  *
  23  *  Anytun is distributed in the hope that it will be useful,
  24  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  26  *  GNU General Public License for more details.
  27  *
  28  *  You should have received a copy of the GNU General Public License
  29  *  along with anytun.  If not, see <http://www.gnu.org/licenses/>.
  30  */
  31
  32 #ifndef _MPI_H_
  33 #define _MPI_H_
  34
  35 #include "datatypes.h"
  36 #include "buffer.h"
  37
  38 #include <gcrypt.h>
  39
  40
  41 /**
  42  * This class is a wrapper for the libgcrypt multi precision integer library [1]
  43  * [1] http://www.gnupg.org/documentation/manuals/gcrypt/MPI-library.html
  44  *
  45  */
  46
  47 class Mpi
  48 {
  49 public:
  50   Mpi();
  51   virtual ~Mpi();
  52   Mpi(u_int8_t length);
  53   Mpi(const Mpi &src);
  54   Mpi(const u_int8_t * src, u_int32_t len);
  55
  56   void operator=(const Mpi &src);
  57   void operator=(u_int32_t src);
  58   Mpi operator+(const Mpi &b) const;
  59   Mpi operator+(const u_int32_t &b) const;
  60   Mpi operator*(const u_int32_t n) const;
  61   Mpi operator/(const Mpi &b) const;
  62
  63   Mpi operator^(const Mpi &b) const;
  64
  65   Mpi mul2exp(u_int32_t e) const;     // value * 2^e
  66
  67   /**
  68    * returns a new[] u_int8_t* buffer with the MPI value in the
  69    * GCRYMPI_FMT_STD (2-complement stored without a length header).<br>
  70    * you have to delete it by hand with delete[]!
  71    * @param buf_len size of the new buffer that is returned
  72    * @return a byte buffer of size buf_len
  73    */
  74   u_int8_t *getNewBuf(size_t* written) const;
  75   std::string getHexDump() const;
  76   u_int32_t getLength() const;
  77
  78 protected:
  79   gcry_mpi_t val_;
  80 };
  81
  82
  83
  84 #endif