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.
14 * Copyright (C) 2007-2009 Othmar Gsenger, Erwin Nindl,
15 * Christian Pointner <satp@wirdorange.org>
17 * This file is part of Anytun.
19 * Anytun is free software: you can redistribute it and/or modify
20 * it under the terms of the GNU General Public License as published by
21 * the Free Software Foundation, either version 3 of the License, or
24 * Anytun is distributed in the hope that it will be useful,
25 * but WITHOUT ANY WARRANTY; without even the implied warranty of
26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
27 * GNU General Public License for more details.
29 * You should have received a copy of the GNU General Public License
30 * along with anytun. If not, see <http://www.gnu.org/licenses/>.
43 #include "anytunError.h"
45 void Cipher::encrypt(KeyDerivation& kd, PlainPacket& in, EncryptedPacket& out, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux)
47 uint32_t len = cipher(kd, in, in.getLength(), out.getPayload(), out.getPayloadLength(), seq_nr, sender_id, mux);
48 out.setSenderId(sender_id);
51 out.setPayloadLength(len);
54 void Cipher::decrypt(KeyDerivation& kd, EncryptedPacket& in, PlainPacket& out)
56 uint32_t len = decipher(kd, in.getPayload() , in.getPayloadLength(), out, out.getLength(), in.getSeqNr(), in.getSenderId(), in.getMux());
61 //******* NullCipher *******
63 uint32_t NullCipher::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)
65 std::memcpy(out, in, (ilen < olen) ? ilen : olen);
66 return (ilen < olen) ? ilen : olen;
69 uint32_t NullCipher::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)
71 std::memcpy(out, in, (ilen < olen) ? ilen : olen);
72 return (ilen < olen) ? ilen : olen;
76 //****** AesIcmCipher ******
78 AesIcmCipher::AesIcmCipher(kd_dir_t d) : Cipher(d), key_(uint32_t(DEFAULT_KEY_LENGTH/8)), salt_(uint32_t(SALT_LENGTH))
83 AesIcmCipher::AesIcmCipher(kd_dir_t d, uint16_t key_length) : Cipher(d), key_(uint32_t(key_length/8)), salt_(uint32_t(SALT_LENGTH))
88 void AesIcmCipher::init(uint16_t key_length)
90 #ifndef USE_SSL_CRYPTO
95 algo = GCRY_CIPHER_AES128;
98 algo = GCRY_CIPHER_AES192;
101 algo = GCRY_CIPHER_AES256;
104 cLog.msg(Log::PRIO_ERROR) << "AesIcmCipher::AesIcmCipher: cipher key length of " << key_length << " Bits is not supported";
109 gcry_error_t err = gcry_cipher_open(&handle_, algo, GCRY_CIPHER_MODE_CTR, 0);
111 cLog.msg(Log::PRIO_ERROR) << "AesIcmCipher::AesIcmCipher: Failed to open cipher" << AnytunGpgError(err);
117 AesIcmCipher::~AesIcmCipher()
119 #ifndef USE_SSL_CRYPTO
121 gcry_cipher_close(handle_);
126 uint32_t AesIcmCipher::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)
128 calc(kd, in, ilen, out, olen, seq_nr, sender_id, mux);
129 return (ilen < olen) ? ilen : olen;
132 uint32_t AesIcmCipher::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)
134 calc(kd, in, ilen, out, olen, seq_nr, sender_id, mux);
135 return (ilen < olen) ? ilen : olen;
138 void AesIcmCipher::calcCtr(KeyDerivation& kd, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux)
140 kd.generate(dir_, LABEL_SALT, seq_nr, salt_);
142 std::memcpy(ctr_.salt_.buf_, salt_.getBuf(), SALT_LENGTH);
143 ctr_.salt_.zero_ = 0;
144 ctr_.params_.mux_ ^= MUX_T_HTON(mux);
145 ctr_.params_.sender_id_ ^= SENDER_ID_T_HTON(sender_id);
146 ctr_.params_.seq_nr_ ^= SEQ_NR_T_HTON(seq_nr);
151 void AesIcmCipher::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)
153 #ifndef USE_SSL_CRYPTO
159 kd.generate(dir_, LABEL_ENC, seq_nr, key_);
160 #ifdef USE_SSL_CRYPTO
161 int ret = AES_set_encrypt_key(key_.getBuf(), key_.getLength()*8, &aes_key_);
163 cLog.msg(Log::PRIO_ERROR) << "AesIcmCipher: Failed to set cipher ssl key (code: " << ret << ")";
167 gcry_error_t err = gcry_cipher_setkey(handle_, key_.getBuf(), key_.getLength());
169 cLog.msg(Log::PRIO_ERROR) << "AesIcmCipher: Failed to set cipher key: " << AnytunGpgError(err);
174 calcCtr(kd, seq_nr, sender_id, mux);
176 #ifndef USE_SSL_CRYPTO
177 err = gcry_cipher_setctr(handle_, ctr_.buf_, CTR_LENGTH);
179 cLog.msg(Log::PRIO_ERROR) << "AesIcmCipher: Failed to set cipher CTR: " << AnytunGpgError(err);
183 err = gcry_cipher_encrypt(handle_, out, olen, in, ilen);
185 cLog.msg(Log::PRIO_ERROR) << "AesIcmCipher: Failed to de/encrypt packet: " << AnytunGpgError(err);
189 if(CTR_LENGTH != AES_BLOCK_SIZE) {
190 cLog.msg(Log::PRIO_ERROR) << "AesIcmCipher: Failed to set cipher CTR: size don't fits";
193 unsigned int num = 0;
194 std::memset(ecount_buf_, 0, AES_BLOCK_SIZE);
195 AES_ctr128_encrypt(in, out, (ilen < olen) ? ilen : olen, &aes_key_, ctr_.buf_, ecount_buf_, &num);