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CnC_Renegade/Code/Launcher/BFISH.H

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/*
** Command & Conquer Renegade(tm)
** Copyright 2025 Electronic Arts Inc.
**
** 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 3 of the License, or
** (at your option) 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, see <http://www.gnu.org/licenses/>.
*/
/***********************************************************************************************
*** C O N F I D E N T I A L --- W E S T W O O D S T U D I O S ***
***********************************************************************************************
* *
* Project Name : Blowfish Component *
* *
* $Archive:: /Commando/Code/Launcher/BFISH.H $*
* *
* $Author:: Denzil_l $*
* *
* $Modtime:: 12/02/97 9:35p $*
* *
* $Revision:: 1 $*
* *
*---------------------------------------------------------------------------------------------*
* Functions: *
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
#ifndef BFISH_H
#define BFISH_H
#include <limits.h>
/*
** This engine will process data blocks by encryption and decryption.
** The "Blowfish" algorithm is in the public domain. It uses
** a Feistal network (similar to IDEA). It has no known
** weaknesses, but is still relatively new. Blowfish is particularly strong
** against brute force attacks. It is also quite strong against linear and
** differential cryptanalysis. Unlike public key encription, it is very
** fast at encryption, as far as cryptography goes. Its weakness is that
** it takes a relatively long time to set up with a new key (1/100th of
** a second on a P6-200). The time to set up a key is equivalent to
** encrypting 4240 bytes.
*/
class BlowfishEngine {
public:
BlowfishEngine(void) : IsKeyed(false) {}
~BlowfishEngine(void);
void Submit_Key(void const * key, int length);
int Encrypt(void const * plaintext, int length, void * cyphertext);
int Decrypt(void const * cyphertext, int length, void * plaintext);
/*
** This is the maximum key length supported.
*/
enum {MAX_KEY_LENGTH=56,
BYTES_PER_BLOCK=8 // The number of bytes in each cypher block (don't change).
};
private:
bool IsKeyed;
void Sub_Key_Encrypt(unsigned long & left, unsigned long & right);
void Process_Block(void const * plaintext, void * cyphertext, unsigned long const * ptable);
void Initialize_Tables(void);
enum {
ROUNDS = 16 // Feistal round count (16 is standard).
};
/*
** Initialization data for sub keys. The initial values are constant and
** filled with a number generated from pi. Thus they are not random but
** they don't hold a weak pattern either.
*/
static unsigned long const P_Init[ROUNDS+2];
static unsigned long const S_Init[4][UCHAR_MAX+1];
/*
** Permutation tables for encryption and decryption.
*/
unsigned long P_Encrypt[ROUNDS+2];
unsigned long P_Decrypt[ROUNDS+2];
/*
** S-Box tables (four).
*/
unsigned long bf_S[4][UCHAR_MAX+1];
};
#endif