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