/*****************************************************************************
 * Author:   Valient Gough <vgough@pobox.com>
 *
 *****************************************************************************
 * Copyright (c) 2004, Valient Gough
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser 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 Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef _NullCipher_incl_
#define _NullCipher_incl_

#include "cipher/Cipher.h"
#include "base/Interface.h"

/*
    Implements Cipher interface for a pass-through mode.  May be useful for
    testing, but that's it.
*/
class NullCipher : public Cipher
{
    Interface iface;

public:
    NullCipher(const Interface &iface);
    virtual ~NullCipher();

    virtual Interface interface() const;

    // create a new key based on a password
    virtual CipherKey newKey(const char *password, int passwdLength,
            int &iterationCount, long desiredDuration,
            const unsigned char *salt, int saltLen);
    virtual CipherKey newKey(const char *password, int passwdLength);
    // create a new random key
    virtual CipherKey newRandomKey();

    // data must be len keySize()
    virtual CipherKey readKey(const unsigned char *data, 
	                      const CipherKey &encodingKey,
			      bool checkKey); 
    virtual void writeKey(const CipherKey &key, unsigned char *data, 
	                  const CipherKey &encodingKey); 
    virtual bool compareKey( const CipherKey &A, 
	                     const CipherKey &B ) const;

    // meta-data about the cypher
    virtual int keySize() const;
    virtual int encodedKeySize() const;
    virtual int cipherBlockSize() const;

    virtual bool randomize( unsigned char *buf, int len,
            bool strongRandom ) const;

    virtual uint64_t MAC_64(const unsigned char *data, int len,
	    const CipherKey &key, uint64_t *chainedIV) const;

    // functional interfaces
    virtual bool streamEncode(unsigned char *in, int len, 
	    uint64_t iv64, const CipherKey &key) const;
    virtual bool streamDecode(unsigned char *in, int len, 
	    uint64_t iv64, const CipherKey &key) const;

    virtual bool blockEncode(unsigned char *buf, int size, 
	             uint64_t iv64, const CipherKey &key) const;
    virtual bool blockDecode(unsigned char *buf, int size, 
	             uint64_t iv64, const CipherKey &key) const;

    // hack to help with static builds
    static bool Enabled();
};


#endif