pkstraw.h

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/*
**  Command & Conquer Generals Zero Hour(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 : Command & Conquer                                            * 
 *                                                                                             * 
 *                     $Archive:: /Commando/Library/PKSTRAW.H                                 $* 
 *                                                                                             * 
 *                      $Author:: Greg_h                                                      $*
 *                                                                                             * 
 *                     $Modtime:: 7/22/97 11:37a                                              $*
 *                                                                                             * 
 *                    $Revision:: 1                                                           $*
 *                                                                                             *
 *---------------------------------------------------------------------------------------------* 
 * Functions:                                                                                  * 
 * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
 
#ifndef PKSTRAW_H
#define PKSTRAW_H
 
#include    "blwstraw.h"
#include    "pk.h"
#include    "pkstraw.h"
#include    "rndstraw.h"
 
class PKStraw : public Straw
{
    public:
        typedef enum CryptControl {
            ENCRYPT,
            DECRYPT
        } CryptControl;
 
        PKStraw(CryptControl control, RandomStraw & rnd);
 
        virtual void Get_From(Straw * straw);
        virtual void Get_From(Straw & straw) {Get_From(&straw);}
 
        virtual int Get(void * source, int slen);
 
        // Submit key to be used for encryption/decryption.
        void Key(PKey const * key);
 
    private:
        enum {
            BLOWFISH_KEY_SIZE=BlowfishEngine::MAX_KEY_LENGTH,
            MAX_KEY_BLOCK_SIZE=256      // Maximum size of pk encrypted blowfish key.
        };
 
        /*
        **  This flag indicates whether the PK (fetch blowfish key) phase is
        **  in progress or not.
        */
        bool IsGettingKey;
 
        /*
        **  This is the random straw that is needed to generate the
        **  blowfish key.
        */
        RandomStraw & Rand;
 
        /*
        **  This is the attached blowfish pipe. After the blowfish key has been
        **  decrypted, then the PK processor goes dormant and the blowfish processor
        **  takes over the data flow.
        */
        BlowStraw BF;
 
        /*
        **  This control member tells what method (encryption or decryption) that should
        **  be performed on the data stream.
        */
        CryptControl Control;
 
        /*
        **  Pointer to the key to use for encryption or decryption. If this pointer is NULL, then
        **  the data passing through this segment will not be modified.
        */
        PKey const * CipherKey;
 
        /*
        **  This is the staging buffer for the block of data. This block must be as large as
        **  the largest possible key size or the largest blowfish key size (whichever is
        **  greater).
        */
        char Buffer[256];
 
        int Counter;
 
        /*
        **  This records the number of bytes remaining in the current block. This
        **  will be the number of bytes left to accumulate before the block can be
        **  processed either for encryption or decryption.
        */
        int BytesLeft;
 
        int Encrypted_Key_Length(void) const;
        int Plain_Key_Length(void) const;
 
        PKStraw(PKStraw & rvalue);
        PKStraw & operator = (PKStraw const & straw);
};
 
#endif