src/authAlgo.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 _AUTHALGO_H_
  33 #define _AUTHALGO_H_
  34
  35 #include "datatypes.h"
  36 #include "buffer.h"
  37 #include "encryptedPacket.h"
  38
  39 #ifndef NOCRYPT
  40 #include <gcrypt.h>
  41 #endif
  42
  43 class AuthAlgo
  44 {
  45 public:
  46   AuthAlgo() {};
  47   virtual ~AuthAlgo() {};
  48
  49   /**
  50    * set the key for the auth algo
  51    * @param key key for hmac calculation
  52    */
  53   virtual void setKey(Buffer& key) = 0;
  54
  55   /**
  56    * generate the mac
  57    * @param packet the packet to be authenticated
  58    */
  59   virtual void generate(EncryptedPacket& packet) = 0;
  60
  61   /**
  62    * check the mac
  63    * @param packet the packet to be authenticated
  64    */
  65   virtual bool checkTag(EncryptedPacket& packet) = 0;
  66
  67   /**
  68    * get the maximum size of the auth algo
  69    */
  70   virtual u_int32_t getMaxLength() = 0;
  71 };
  72
  73 //****** NullAuthAlgo ******
  74
  75 class NullAuthAlgo : public AuthAlgo
  76 {
  77 public:
  78   void setKey(Buffer& key) {};
  79   void generate(EncryptedPacket& packet);
  80   bool checkTag(EncryptedPacket& packet);
  81   u_int32_t getMaxLength();
  82
  83   static const u_int32_t MAX_LENGTH_ = 0;
  84 };
  85
  86 #ifndef NOCRYPT
  87 //****** Sha1AuthAlgo ******
  88 //* HMAC SHA1 Auth Tag Generator Class
  89
  90 class Sha1AuthAlgo : public AuthAlgo
  91 {
  92 public:
  93   Sha1AuthAlgo();
  94   ~Sha1AuthAlgo();
  95
  96   void setKey(Buffer& key);
  97   void generate(EncryptedPacket& packet);
  98   bool checkTag(EncryptedPacket& packet);
  99   u_int32_t getMaxLength();
 100
 101   static const u_int32_t MAX_LENGTH_ = 20;
 102
 103 private:
 104   gcry_md_hd_t ctx_;
 105 };
 106 #endif
 107
 108 #endif