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