106 lines
4.3 KiB
C++
106 lines
4.3 KiB
C++
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/*
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** Command & Conquer Generals Zero Hour(tm)
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** Copyright 2025 Electronic Arts Inc.
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**
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** This program is free software: you can redistribute it and/or modify
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** it under the terms of the GNU General Public License as published by
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** the Free Software Foundation, either version 3 of the License, or
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** (at your option) any later version.
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**
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** This program is distributed in the hope that it will be useful,
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** but WITHOUT ANY WARRANTY; without even the implied warranty of
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** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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** GNU General Public License for more details.
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**
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** You should have received a copy of the GNU General Public License
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** along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/***********************************************************************************************
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*** 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 ***
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***********************************************************************************************
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* *
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* Project Name : Blowfish Component *
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* *
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* $Archive:: /Sun/Blowfish/bfish.h $*
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* *
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* $Author:: Joe_b $*
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* *
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* $Modtime:: 12/02/97 9:35p $*
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* *
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* $Revision:: 6 $*
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* *
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*---------------------------------------------------------------------------------------------*
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* Functions: *
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* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
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#ifndef BFISH_H
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#define BFISH_H
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#include <limits.h>
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/*
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** This engine will process data blocks by encryption and decryption.
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** The "Blowfish" algorithm is in the public domain. It uses
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** a Feistal network (similar to IDEA). It has no known
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** weaknesses, but is still relatively new. Blowfish is particularly strong
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** against brute force attacks. It is also quite strong against linear and
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** differential cryptanalysis. Unlike public key encription, it is very
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** fast at encryption, as far as cryptography goes. Its weakness is that
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** it takes a relatively long time to set up with a new key (1/100th of
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** a second on a P6-200). The time to set up a key is equivalent to
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** encrypting 4240 bytes.
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*/
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class BlowfishEngine {
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public:
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BlowfishEngine(void) : IsKeyed(false) {}
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~BlowfishEngine(void);
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void Submit_Key(void const * key, int length);
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int Encrypt(void const * plaintext, int length, void * cyphertext);
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int Decrypt(void const * cyphertext, int length, void * plaintext);
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/*
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** This is the maximum key length supported.
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*/
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enum {MAX_KEY_LENGTH=56,
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BYTES_PER_BLOCK=8 // The number of bytes in each cypher block (don't change).
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};
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private:
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bool IsKeyed;
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void Sub_Key_Encrypt(unsigned long & left, unsigned long & right);
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void Process_Block(void const * plaintext, void * cyphertext, unsigned long const * ptable);
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void Initialize_Tables(void);
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enum {
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ROUNDS = 16 // Feistal round count (16 is standard).
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};
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/*
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** Initialization data for sub keys. The initial values are constant and
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** filled with a number generated from pi. Thus they are not random but
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** they don't hold a weak pattern either.
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*/
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static unsigned long const P_Init[ROUNDS+2];
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static unsigned long const S_Init[4][UCHAR_MAX+1];
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/*
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** Permutation tables for encryption and decryption.
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*/
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unsigned long P_Encrypt[ROUNDS+2];
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unsigned long P_Decrypt[ROUNDS+2];
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/*
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** S-Box tables (four).
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*/
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unsigned long bf_S[4][UCHAR_MAX+1];
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};
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#endif
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