src/cipher.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 _CIPHER_H_
  33 #define _CIPHER_H_
  34
  35 #include "datatypes.h"
  36 #include "buffer.h"
  37 #include "encryptedPacket.h"
  38 #include "plainPacket.h"
  39 #include "keyDerivation.h"
  40
  41 #ifndef NOCRYPT
  42 #ifndef USE_SSL_CRYPTO
  43 #include <gcrypt.h>
  44 #else
  45 #include <openssl/aes.h>
  46 #endif
  47 #endif
  48
  49 class Cipher
  50 {
  51 public:
  52   Cipher() : dir_(KD_INBOUND) {};
  53   Cipher(kd_dir_t d) : dir_(d) {};
  54   virtual ~Cipher() {};
  55
  56         void encrypt(KeyDerivation& kd, PlainPacket & in, EncryptedPacket & out, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux);
  57         void decrypt(KeyDerivation& kd, EncryptedPacket & in, PlainPacket & out);
  58
  59 protected:
  60   virtual u_int32_t cipher(KeyDerivation& kd, u_int8_t* in, u_int32_t ilen, u_int8_t* out, u_int32_t olen, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux) = 0;
  61   virtual u_int32_t decipher(KeyDerivation& kd, u_int8_t* in, u_int32_t ilen, u_int8_t* out, u_int32_t olen, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux) = 0;
  62
  63   kd_dir_t dir_;
  64 };
  65
  66 //****** NullCipher ******
  67
  68 class NullCipher : public Cipher
  69 {
  70 protected:
  71   u_int32_t cipher(KeyDerivation& kd, u_int8_t* in, u_int32_t ilen, u_int8_t* out, u_int32_t olen, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux);
  72   u_int32_t decipher(KeyDerivation& kd, u_int8_t* in, u_int32_t ilen, u_int8_t* out, u_int32_t olen, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux);
  73 };
  74
  75 #ifndef NOCRYPT
  76 //****** AesIcmCipher ******
  77
  78 class AesIcmCipher : public Cipher
  79 {
  80 public:
  81   AesIcmCipher(kd_dir_t d);
  82   AesIcmCipher(kd_dir_t d, u_int16_t key_length);
  83   ~AesIcmCipher();
  84
  85   static const u_int16_t DEFAULT_KEY_LENGTH = 128;
  86   static const u_int16_t CTR_LENGTH = 16;
  87   static const u_int16_t SALT_LENGTH = 14;
  88
  89 protected:
  90   u_int32_t cipher(KeyDerivation& kd, u_int8_t* in, u_int32_t ilen, u_int8_t* out, u_int32_t olen, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux);
  91   u_int32_t decipher(KeyDerivation& kd, u_int8_t* in, u_int32_t ilen, u_int8_t* out, u_int32_t olen, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux);
  92
  93 private:
  94   void init(u_int16_t key_length = DEFAULT_KEY_LENGTH);
  95
  96   void calcCtr(KeyDerivation& kd, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux);
  97   void calc(KeyDerivation& kd, u_int8_t* in, u_int32_t ilen, u_int8_t* out, u_int32_t olen, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux);
  98
  99 #ifndef USE_SSL_CRYPTO
 100   gcry_cipher_hd_t handle_;
 101 #else
 102   AES_KEY aes_key_;
 103   u_int8_t ecount_buf_[AES_BLOCK_SIZE];
 104 #endif
 105   Buffer key_;
 106   Buffer salt_;
 107
 108 #ifdef _MSC_VER
 109   #pragma pack(push, 1)
 110 #endif
 111   union ATTR_PACKED cipher_aesctr_ctr_union {
 112     u_int8_t buf_[CTR_LENGTH];
 113     struct ATTR_PACKED {
 114       u_int8_t buf_[SALT_LENGTH];
 115       u_int16_t zero_;
 116     } salt_;
 117         struct ATTR_PACKED {
 118       u_int8_t fill_[SALT_LENGTH - sizeof(mux_t) - sizeof(sender_id_t) - 2 - sizeof(seq_nr_t)];
 119       mux_t mux_;
 120       sender_id_t sender_id_;
 121       u_int8_t empty_[2];
 122       seq_nr_t seq_nr_;
 123       u_int16_t zero_;
 124     } params_;
 125   } ctr_;
 126 #ifdef _MSC_VER
 127   #pragma pack(pop)
 128 #endif
 129 };
 130 #endif
 131
 132 #endif