From 3d174037c175e33b0b57c0639ab7440e9f5d6abc Mon Sep 17 00:00:00 2001 From: Christian Pointner Date: Tue, 19 Feb 2008 17:31:04 +0000 Subject: replaces cypher with cipher --- cipher.cpp | 144 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 144 insertions(+) create mode 100644 cipher.cpp (limited to 'cipher.cpp') diff --git a/cipher.cpp b/cipher.cpp new file mode 100644 index 0000000..d68204c --- /dev/null +++ b/cipher.cpp @@ -0,0 +1,144 @@ +/* + * 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 methodes 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 anytun.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + * + * This program 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 this program (see the file COPYING included with this + * distribution); if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include +#include +#include +#include +#include + +#include "cipher.h" +#include "mpi.h" +#include "log.h" + +void Cipher::encrypt(const PlainPacket & in,EncryptedPacket & out, seq_nr_t seq_nr, sender_id_t sender_id) +{ + cipher(out.payload_, in.complete_payload_ , in.complete_payload_length_, seq_nr, sender_id); + out.setSenderId(sender_id); + out.setSeqNr(seq_nr); + out.setPayloadLength(in.complete_payload_length_); +} + +void Cipher::decrypt(const EncryptedPacket & in,PlainPacket & out) +{ + cipher(out.complete_payload_, in.payload_ , in.payload_length_, in.getSeqNr(), in.getSenderId()); + out.setCompletePayloadLength(in.payload_length_); +} + + + +//****** NullCipher ****** + +void NullCipher::cipher(u_int8_t * out, u_int8_t * in, u_int32_t length, seq_nr_t seq_nr, sender_id_t sender_id) +{ + std::memcpy(out, in, length ); +} + + + +//****** AesIcmCipher ****** + +AesIcmCipher::AesIcmCipher() : salt_(Buffer(14)) // Q@NINE 14?????? +{ + gcry_error_t err; + + // TODO: hardcoded keysize!!!!! + err = gcry_cipher_open( &cipher_, GCRY_CIPHER_AES128, GCRY_CIPHER_MODE_CTR, 0 ); + if( err ) + cLog.msg(Log::PRIO_CRIT) << "AesIcmCipher::AesIcmCipher: Failed to open cipher"; +} + + +AesIcmCipher::~AesIcmCipher() +{ + gcry_cipher_close( cipher_ ); + cLog.msg(Log::PRIO_DEBUG) << "AesIcmCipher::~AesIcmCipher: closed cipher"; +} + + +void AesIcmCipher::setKey(Buffer key) +{ + gcry_error_t err; + + err = gcry_cipher_setkey( cipher_, key.getBuf(), key.getLength() ); + if( err ) + cLog.msg(Log::PRIO_ERR) << "AesIcmCipher::setKey: Failed to set cipher key: " << gpg_strerror( err ); +} + +void AesIcmCipher::setSalt(Buffer salt) +{ + salt_ = salt; +} + +void AesIcmCipher::cipher(u_int8_t * out, u_int8_t * in, u_int32_t length, seq_nr_t seq_nr, sender_id_t sender_id) +{ + gcry_error_t err; + + // set the IV + //========================================================================== + // // where the 128-bit integer value IV SHALL be defined by the SSRC, the + // // SRTP packet index i, and the SRTP session salting key k_s, as below. + // // + // // IV = (k_s * 2^16) XOR (SSRC * 2^64) XOR (i * 2^16) + // // sizeof(k_s) = 112 bit, random + + Mpi iv(128); // TODO: hardcoded size + Mpi salt = Mpi(salt_.getBuf(), salt_.getLength()); + Mpi sid = sender_id; + Mpi seq = seq_nr; + + iv = salt.mul2exp(16) ^ sid.mul2exp(64) ^ seq.mul2exp(16); // TODO: hardcoded size + + u_int8_t *iv_buf = iv.getNewBuf(16); // TODO: hardcoded size + + // Q@NINE -> CTR Mode -> gcry_cipher_setctr() ???? + + err = gcry_cipher_setiv( cipher_, iv_buf, 16 ); // TODO: hardcoded size + delete[] iv_buf; + if( err ) { + cLog.msg(Log::PRIO_ERR) << "AesIcmCipher: Failed to set cipher IV: " << gpg_strerror( err ); + return; + } + + // Q@NINE -> reset clears IV ???? + + err = gcry_cipher_reset( cipher_ ); + if( err ) { + cLog.msg(Log::PRIO_ERR) << "AesIcmCipher: Failed to reset cipher: " << gpg_strerror( err ); + return; + } + + err = gcry_cipher_encrypt( cipher_, out, length, in, length ); + if( err ) { + cLog.msg(Log::PRIO_ERR) << "AesIcmCipher: Failed to generate cipher bitstream: " << gpg_strerror( err ); + return; + } +} + -- cgit v1.2.3