summaryrefslogtreecommitdiff
path: root/src/cipher.h
blob: 9de463a055bd799f100e6472dbc070a32d4c6ee8 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
/*
 *  anytun
 *
 *  The secure anycast tunneling protocol (satp) defines a protocol used
 *  for communication between any combination of unicast and anycast
 *  tunnel endpoints.  It has less protocol overhead than IPSec in Tunnel
 *  mode and allows tunneling of every ETHER TYPE protocol (e.g.
 *  ethernet, ip, arp ...). satp directly includes cryptography and
 *  message authentication based on the methods used by SRTP.  It is
 *  intended to deliver a generic, scaleable and secure solution for
 *  tunneling and relaying of packets of any protocol.
 *
 *
 *  Copyright (C) 2007-2009 Othmar Gsenger, Erwin Nindl,
 *                          Christian Pointner <satp@wirdorange.org>
 *
 *  This file is part of Anytun.
 *
 *  Anytun is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  any later version.
 *
 *  Anytun is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with anytun.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef ANYTUN_cipher_h_INCLUDED
#define ANYTUN_cipher_h_INCLUDED

#include "datatypes.h"
#include "buffer.h"
#include "encryptedPacket.h"
#include "plainPacket.h"
#include "keyDerivation.h"

#ifndef NO_CRYPT
#ifndef USE_SSL_CRYPTO
#include <gcrypt.h>
#else
#include <openssl/aes.h>
#endif
#endif

class Cipher
{
public:
  Cipher() : dir_(KD_INBOUND) {};
  Cipher(kd_dir_t d) : dir_(d) {};
  virtual ~Cipher() {};

  void encrypt(KeyDerivation& kd, PlainPacket& in, EncryptedPacket& out, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux);
  void decrypt(KeyDerivation& kd, EncryptedPacket& in, PlainPacket& out);

protected:
  virtual uint32_t cipher(KeyDerivation& kd, uint8_t* in, uint32_t ilen, uint8_t* out, uint32_t olen, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux) = 0;
  virtual uint32_t decipher(KeyDerivation& kd, uint8_t* in, uint32_t ilen, uint8_t* out, uint32_t olen, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux) = 0;

  kd_dir_t dir_;
};

//****** NullCipher ******

class NullCipher : public Cipher
{
protected:
  uint32_t cipher(KeyDerivation& kd, uint8_t* in, uint32_t ilen, uint8_t* out, uint32_t olen, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux);
  uint32_t decipher(KeyDerivation& kd, uint8_t* in, uint32_t ilen, uint8_t* out, uint32_t olen, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux);
};

#ifndef NO_CRYPT
//****** AesIcmCipher ******

class AesIcmCipher : public Cipher
{
public:
  AesIcmCipher(kd_dir_t d);
  AesIcmCipher(kd_dir_t d, uint16_t key_length);
  ~AesIcmCipher();

  static const uint16_t DEFAULT_KEY_LENGTH = 128;
  static const uint16_t CTR_LENGTH = 16;
  static const uint16_t SALT_LENGTH = 14;

protected:
  uint32_t cipher(KeyDerivation& kd, uint8_t* in, uint32_t ilen, uint8_t* out, uint32_t olen, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux);
  uint32_t decipher(KeyDerivation& kd, uint8_t* in, uint32_t ilen, uint8_t* out, uint32_t olen, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux);

private:
  void init(uint16_t key_length = DEFAULT_KEY_LENGTH);

  void calcCtr(KeyDerivation& kd, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux);
  void calc(KeyDerivation& kd, uint8_t* in, uint32_t ilen, uint8_t* out, uint32_t olen, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux);

#ifndef USE_SSL_CRYPTO
  gcry_cipher_hd_t handle_;
#else
  AES_KEY aes_key_;
  uint8_t ecount_buf_[AES_BLOCK_SIZE];
#endif
  Buffer key_;
  Buffer salt_;

#ifdef _MSC_VER
#pragma pack(push, 1)
#endif
  union ATTR_PACKED cipher_aesctr_ctr_union {
    uint8_t buf_[CTR_LENGTH];
    struct ATTR_PACKED {
      uint8_t buf_[SALT_LENGTH];
      uint16_t zero_;
    } salt_;
    struct ATTR_PACKED {
      uint8_t fill_[SALT_LENGTH - sizeof(mux_t) - sizeof(sender_id_t) - 2*sizeof(uint8_t) - sizeof(seq_nr_t)];
      mux_t mux_;
      sender_id_t sender_id_;
      uint8_t empty_[2];
      seq_nr_t seq_nr_;
      uint16_t zero_;
    } params_;
  } ctr_;
#ifdef _MSC_VER
#pragma pack(pop)
#endif
};
#endif

#endif