/* Menes - C++ High-Level Utility Library * Copyright (C) 2004-2005 Jay Freeman (saurik) */ /* * Redistribution and use in source and binary * forms, with or without modification, are permitted * provided that the following conditions are met: * * 1. Redistributions of source code must retain the * above copyright notice, this list of conditions * and the following disclaimer. * 2. Redistributions in binary form must reproduce the * above copyright notice, this list of conditions * and the following disclaimer in the documentation * and/or other materials provided with the * distribution. * 3. The name of the author may not be used to endorse * or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include "cxx/standard.hh" #pragma hdrstop("build/cxx/standard.pch") #include "enc/encrypt/rc2.hpp" #include "ext/byteorder.hpp" #include "ext/shift.hpp" namespace enc { void Rc2Crypter::MixRound_(unsigned &used, uint16_t text[4]) const { static const unsigned shifts[] = {1, 2, 3, 5}; _forall (unsigned, i, 0, 4) text[i] = ext::LeftCircleShift( text[i] + key16_[used++] + (text[(i - 1) % 4] & text[(i - 2) % 4]) + (~text[(i - 1) % 4] & text[(i - 3) % 4]), shifts[i] ); } void Rc2Crypter::MashRound_(unsigned &used, uint16_t text[4]) const { _forall (unsigned, i, 0, 4) text[i] += key16_[text[(i - 1) % 4] & 63]; } void Rc2Crypter::ReverseMixRound_(unsigned &used, uint16_t text[4]) const { static const unsigned shifts[] = {1, 2, 3, 5}; _rforall (unsigned, i, 0, 4) { text[i] = ext::RightCircleShift(text[i], shifts[i]); text[i] -= key16_[used--] + (text[(i - 1) % 4] & text[(i - 2) % 4]) + (~text[(i - 1) % 4] & text[(i - 3) % 4]); } } void Rc2Crypter::ReverseMashRound_(unsigned &used, uint16_t text[4]) const { _rforall (unsigned, i, 0, 4) text[i] -= key16_[text[(i - 1) % 4] & 63]; } Rc2Crypter::Rc2Crypter(const ext::Buffer &key, unsigned bits) { static const uint8_t pitable_[256] = { 0xd9, 0x78, 0xf9, 0xc4, 0x19, 0xdd, 0xb5, 0xed, 0x28, 0xe9, 0xfd, 0x79, 0x4a, 0xa0, 0xd8, 0x9d, 0xc6, 0x7e, 0x37, 0x83, 0x2b, 0x76, 0x53, 0x8e, 0x62, 0x4c, 0x64, 0x88, 0x44, 0x8b, 0xfb, 0xa2, 0x17, 0x9a, 0x59, 0xf5, 0x87, 0xb3, 0x4f, 0x13, 0x61, 0x45, 0x6d, 0x8d, 0x09, 0x81, 0x7d, 0x32, 0xbd, 0x8f, 0x40, 0xeb, 0x86, 0xb7, 0x7b, 0x0b, 0xf0, 0x95, 0x21, 0x22, 0x5c, 0x6b, 0x4e, 0x82, 0x54, 0xd6, 0x65, 0x93, 0xce, 0x60, 0xb2, 0x1c, 0x73, 0x56, 0xc0, 0x14, 0xa7, 0x8c, 0xf1, 0xdc, 0x12, 0x75, 0xca, 0x1f, 0x3b, 0xbe, 0xe4, 0xd1, 0x42, 0x3d, 0xd4, 0x30, 0xa3, 0x3c, 0xb6, 0x26, 0x6f, 0xbf, 0x0e, 0xda, 0x46, 0x69, 0x07, 0x57, 0x27, 0xf2, 0x1d, 0x9b, 0xbc, 0x94, 0x43, 0x03, 0xf8, 0x11, 0xc7, 0xf6, 0x90, 0xef, 0x3e, 0xe7, 0x06, 0xc3, 0xd5, 0x2f, 0xc8, 0x66, 0x1e, 0xd7, 0x08, 0xe8, 0xea, 0xde, 0x80, 0x52, 0xee, 0xf7, 0x84, 0xaa, 0x72, 0xac, 0x35, 0x4d, 0x6a, 0x2a, 0x96, 0x1a, 0xd2, 0x71, 0x5a, 0x15, 0x49, 0x74, 0x4b, 0x9f, 0xd0, 0x5e, 0x04, 0x18, 0xa4, 0xec, 0xc2, 0xe0, 0x41, 0x6e, 0x0f, 0x51, 0xcb, 0xcc, 0x24, 0x91, 0xaf, 0x50, 0xa1, 0xf4, 0x70, 0x39, 0x99, 0x7c, 0x3a, 0x85, 0x23, 0xb8, 0xb4, 0x7a, 0xfc, 0x02, 0x36, 0x5b, 0x25, 0x55, 0x97, 0x31, 0x2d, 0x5d, 0xfa, 0x98, 0xe3, 0x8a, 0x92, 0xae, 0x05, 0xdf, 0x29, 0x10, 0x67, 0x6c, 0xba, 0xc9, 0xd3, 0x00, 0xe6, 0xcf, 0xe1, 0x9e, 0xa8, 0x2c, 0x63, 0x16, 0x01, 0x3f, 0x58, 0xe2, 0x89, 0xa9, 0x0d, 0x38, 0x34, 0x1b, 0xab, 0x33, 0xff, 0xb0, 0xbb, 0x48, 0x0c, 0x5f, 0xb9, 0xb1, 0xcd, 0x2e, 0xc5, 0xf3, 0xdb, 0x47, 0xe5, 0xa5, 0x9c, 0x77, 0x0a, 0xa6, 0x20, 0x68, 0xfe, 0x7f, 0xc1, 0xad }; _assert(!key.IsEmpty()); _assert(key.GetSize() <= 128); _assert(key.GetSize() == (bits + 7) / 8); unsigned bytes(key.GetSize()); ext::CopyAssign(key8_, key.Begin(), bytes); // XXX: analyze efficiency of this algorithm vs my standard ~(~ << ) trick uint8_t mask(255 % (1 << (8 + bits - 8 * bytes))); _forall (unsigned, i, bytes, 128) key8_[i] = pitable_[(key8_[i - 1] + key8_[i - bytes]) % 256]; key8_[128 - bytes] = pitable_[key8_[128 - bytes] & mask]; _rforall (unsigned, i, 0, 128 - bytes) key8_[i] = pitable_[key8_[i + 1] ^ key8_[i + bytes]]; _forall (unsigned, i, 0, 64) key16_[i] = ext::LittleEndianOrder::Decode(key16_[i]); } void Rc2Crypter::Encrypt(byte_t text[4]) const { unsigned used(0); uint16_t * const text16(reinterpret_cast(text)); _forall (unsigned, i, 0, 4) text16[i] = ext::LittleEndianOrder::Decode(text16[i]); _repeat(5) MixRound_(used, text16); MashRound_(used, text16); _repeat(6) MixRound_(used, text16); MashRound_(used, text16); _repeat(5) MixRound_(used, text16); _forall (unsigned, i, 0, 4) text16[i] = ext::LittleEndianOrder::Encode(text16[i]); } void Rc2Crypter::Decrypt(byte_t text[4]) const { unsigned used(63); uint16_t * const text16(reinterpret_cast(text)); _forall (unsigned, i, 0, 4) text16[i] = ext::LittleEndianOrder::Decode(text16[i]); _repeat(5) ReverseMixRound_(used, text16); ReverseMashRound_(used, text16); _repeat(6) ReverseMixRound_(used, text16); ReverseMashRound_(used, text16); _repeat(5) ReverseMixRound_(used, text16); _forall (unsigned, i, 0, 4) text16[i] = ext::LittleEndianOrder::Encode(text16[i]); } Rc2Encrypter::Rc2Encrypter(const _R &writer, const ext::Buffer &key, unsigned bits) : writer_(writer), crypter_(key, bits) { } void Rc2Encrypter::Write_(const byte_t *data) { byte_t text[8]; ext::CopyAssign(text, data, 8); crypter_.Encrypt(text); writer_->WriteFully(text, 8); } void Rc2Encrypter::Close_(const byte_t *data, size_t length) { _assert(length == 0); } Rc2Decrypter::Rc2Decrypter(const _R &writer, const ext::Buffer &key, unsigned bits) : writer_(writer), crypter_(key, bits) { } void Rc2Decrypter::Write_(const byte_t *data) { byte_t text[8]; ext::CopyAssign(text, data, 8); crypter_.Decrypt(text); writer_->WriteFully(text, 8); } void Rc2Decrypter::Close_(const byte_t *data, size_t length) { _assert(length == 0); } }