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Diffstat (limited to 'src/modules/rijndael/ablowfish.h')
| -rw-r--r-- | src/modules/rijndael/ablowfish.h | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/src/modules/rijndael/ablowfish.h b/src/modules/rijndael/ablowfish.h new file mode 100644 index 00000000..862477dc --- /dev/null +++ b/src/modules/rijndael/ablowfish.h @@ -0,0 +1,141 @@ +#ifndef _BLOWFISH_H_ +#define _BLOWFISH_H_ +//============================================================================= +// +// File : ablowfish.h +// Creation date : Wed Jan 13 2005 02:04:10 CEST by Szymon Stefanek +// +// This file is part of the KVirc irc client distribution +// Copyright (C) 2005 Szymon Stefanek (pragma at kvirc dot net) +// +// This program 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 2 +// of the License, or (at your opinion) any later version. +// +// 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. If not, write to the Free Software Foundation, +// Inc. ,51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. +// +//============================================================================= + +// +// This code is adapted from the MircCryption engine suite by Dark Raichu +// Original comments follow. +// + +//--------------------------------------------------------------------------- +// The implementation of blowfish for CBC mode is from +// http://www.thecodeproject.com/cpp/blowfish.asp by George Anescu +// I removed exception handling, so it is callers responsibility to insure +// that strings are length multiples of 8 bytes +// -mouser 1/08/05 +//--------------------------------------------------------------------------- + + +// +// BLOWFISH ENCRYPTION ALGORITHM +// +// Implementation of Bruce Schneier's BLOWFISH algorithm from "Applied +// Cryptography", Second Edition. +// +// Encryption and Decryption of Byte Strings using the Blowfish Encryption Algorithm. +// Blowfish is a block cipher that encrypts data in 8-byte blocks. The algorithm consists +// of two parts: a key-expansion part and a data-ancryption part. Key expansion converts a +// variable key of at least 1 and at most 56 bytes into several subkey arrays totaling +// 4168 bytes. Blowfish has 16 rounds. Each round consists of a key-dependent permutation, +// and a key and data-dependent substitution. All operations are XORs and additions on 32-bit words. +// The only additional operations are four indexed array data lookups per round. +// Blowfish uses a large number of subkeys. These keys must be precomputed before any data +// encryption or decryption. The P-array consists of 18 32-bit subkeys: P0, P1,...,P17. +// There are also four 32-bit S-boxes with 256 entries each: S0,0, S0,1,...,S0,255; +// S1,0, S1,1,...,S1,255; S2,0, S2,1,...,S2,255; S3,0, S3,1,...,S3,255; +// +// The Electronic Code Book (ECB), Cipher Block Chaining (CBC) and Cipher Feedback modes +// are used: +// +// In ECB mode if the same block is encrypted twice with the same key, the resulting +// ciphertext blocks are the same. +// +// In CBC Mode a ciphertext block is obtained by first xoring the +// plaintext block with the previous ciphertext block, and encrypting the resulting value. +// +// In CFB mode a ciphertext block is obtained by encrypting the previous ciphertext block +// and xoring the resulting value with the plaintext +// +// The previous ciphertext block is usually stored in an Initialization Vector (IV). +// An Initialization Vector of zero is commonly used for the first block, though other +// arrangements are also in use. +// + +#include "kvi_settings.h" + +#ifdef COMPILE_CRYPT_SUPPORT + + +//Block Structure +struct SBlock +{ + //Constructors + SBlock(unsigned int l=0, unsigned int r=0) : m_uil(l), m_uir(r) {} + //Copy Constructor + SBlock(const SBlock& roBlock) : m_uil(roBlock.m_uil), m_uir(roBlock.m_uir) {} + SBlock& operator^=(SBlock& b) { m_uil ^= b.m_uil; m_uir ^= b.m_uir; return *this; } + unsigned int m_uil, m_uir; +}; + +class BlowFish +{ +public: + enum { ECB=0, CBC=1, CFB=2 }; + + //Constructor - Initialize the P and S boxes for a given Key + BlowFish(unsigned char* ucKey, unsigned int n, const SBlock& roChain = SBlock(0UL,0UL)); + + //Resetting the chaining block + void ResetChain() { m_oChain = m_oChain0; } + + // Encrypt/Decrypt Buffer in Place + void Encrypt(unsigned char* buf, unsigned int n, int iMode=ECB); + void Decrypt(unsigned char* buf, unsigned int n, int iMode=ECB); + + // Encrypt/Decrypt from Input Buffer to Output Buffer + void Encrypt(const unsigned char* in, unsigned char* out, unsigned int n, int iMode=ECB); + void Decrypt(const unsigned char* in, unsigned char* out, unsigned int n, int iMode=ECB); + +//Private Functions +private: + unsigned int F(unsigned int ui); + void Encrypt(SBlock&); + void Decrypt(SBlock&); + +private: + //The Initialization Vector, by default {0, 0} + SBlock m_oChain0; + SBlock m_oChain; + unsigned int m_auiP[18]; + unsigned int m_auiS[4][256]; + static const unsigned int scm_auiInitP[18]; + static const unsigned int scm_auiInitS[4][256]; +}; + +//Extract low order byte +inline unsigned char Byte(unsigned int ui) +{ + return (unsigned char)(ui & 0xff); +} + +//Function F +inline unsigned int BlowFish::F(unsigned int ui) +{ + return ((m_auiS[0][Byte(ui>>24)] + m_auiS[1][Byte(ui>>16)]) ^ m_auiS[2][Byte(ui>>8)]) + m_auiS[3][Byte(ui)]; +} + +#endif //COMPILE_CRYPT_SUPPORT + +#endif //!_BLOWFISH_H_ |