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 anytun.org <satp@wirdorange.org>
  15  *
  16  *  This program is free software; you can redistribute it and/or modify
  17  *  it under the terms of the GNU General Public License version 2
  18  *  as published by the Free Software Foundation.
  19  *
  20  *  This program is distributed in the hope that it will be useful,
  21  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  *  GNU General Public License for more details.
  24  *
  25  *  You should have received a copy of the GNU General Public License
  26  *  along with this program (see the file COPYING included with this
  27  *  distribution); if not, write to the Free Software Foundation, Inc.,
  28  *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  29  */
  30
  31 #ifndef _MPI_H_
  32 #define _MPI_H_
  33
  34 #include "datatypes.h"
  35 #include "buffer.h"
  36
  37 #include <gcrypt.h>
  38
  39
  40 /**
  41  * This class is a wrapper for the libgcrypt multi precision integer library [1]
  42  * [1] http://www.gnupg.org/documentation/manuals/gcrypt/MPI-library.html
  43  *
  44  */
  45
  46 class Mpi
  47 {
  48 public:
  49   Mpi();
  50   virtual ~Mpi();
  51   Mpi(u_int8_t length);
  52   Mpi(const Mpi &src);
  53   Mpi(const u_int8_t * src, u_int32_t len);
  54
  55   void operator=(const Mpi &src);
  56   void operator=(u_int32_t src);
  57   Mpi operator+(const Mpi &b) const;
  58   Mpi operator+(const u_int32_t &b) const;
  59   Mpi operator*(const u_int32_t n) const;
  60   Mpi operator/(const Mpi &b) const;
  61
  62   Mpi operator^(const Mpi &b) const;
  63
  64   Mpi mul2exp(u_int32_t e) const;     // value * 2^e
  65
  66   /**
  67    * returns a new[] u_int8_t* buffer with the MPI value in the
  68    * GCRYMPI_FMT_STD (2-complement stored without a length header).<br>
  69    * you have to delete it by hand with delete[]!
  70    * @param buf_len size of the new buffer that is returned
  71    * @return a byte buffer of size buf_len
  72    */
  73   u_int8_t *getNewBuf(size_t* written) const;
  74   std::string getHexDump() const;
  75   u_int32_t getLength() const;
  76
  77 protected:
  78   gcry_mpi_t val_;
  79 };
  80
  81
  82
  83 #endif