bf_enc.cpp

这是一个blowfish加密算法。该算法是从speakfs提取

/* crypto/bf/bf_enc.c */
/* Copyright (C) 1995-1997 Eric Young ([e-mail])
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young ([e-mail]).
 * The implementation was written so as to conform with Netscapes SSL.
 * 
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson ([e-mail]).
 * 
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young ([e-mail])"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from 
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson ([e-mail])"
 * 
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * 
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include "blowfish.h"
#include "bf_locl.h"

/* Blowfish as implemented from 'Blowfish: Springer-Verlag paper'
 * (From LECTURE NOTES IN COIMPUTER SCIENCE 809, FAST SOFTWARE ENCRYPTION,
 * CAMBRIDGE SECURITY WORKSHOP, CAMBRIDGE, U.K., DECEMBER 9-11, 1993)
 */

#if (BF_ROUNDS != 16) && (BF_ROUNDS != 20)
If you set BF_ROUNDS to some value other than 16 or 20, you will have
to modify the code.
#endif

void BF_encrypt(BF_LONG *data, BF_KEY *key, int encrypt)
//BF_LONG *data;
//BF_KEY *key;
//int encrypt;
        {
        register BF_LONG l,r,*p,*s;

        p=key->P;
        s= &(key->S[0]);
        l=data[0];
        r=data[1];

        if (encrypt)
                {
                l^=p[0];
                BF_ENC(r,l,s,p[ 1]);
                BF_ENC(l,r,s,p[ 2]);
                BF_ENC(r,l,s,p[ 3]);
                BF_ENC(l,r,s,p[ 4]);
                BF_ENC(r,l,s,p[ 5]);
                BF_ENC(l,r,s,p[ 6]);
                BF_ENC(r,l,s,p[ 7]);
                BF_ENC(l,r,s,p[ 8]);
                BF_ENC(r,l,s,p[ 9]);
                BF_ENC(l,r,s,p[10]);
                BF_ENC(r,l,s,p[11]);
                BF_ENC(l,r,s,p[12]);
                BF_ENC(r,l,s,p[13]);
                BF_ENC(l,r,s,p[14]);
                BF_ENC(r,l,s,p[15]);
                BF_ENC(l,r,s,p[16]);
#if BF_ROUNDS == 20
                BF_ENC(r,l,s,p[17]);
                BF_ENC(l,r,s,p[18]);
                BF_ENC(r,l,s,p[19]);
                BF_ENC(l,r,s,p[20]);
#endif
                r^=p[BF_ROUNDS+1];
                }
        else
                {
                l^=p[BF_ROUNDS+1];
#if BF_ROUNDS == 20
                BF_ENC(r,l,s,p[20]);
                BF_ENC(l,r,s,p[19]);
                BF_ENC(r,l,s,p[18]);
                BF_ENC(l,r,s,p[17]);
#endif
                BF_ENC(r,l,s,p[16]);
                BF_ENC(l,r,s,p[15]);
                BF_ENC(r,l,s,p[14]);
                BF_ENC(l,r,s,p[13]);
                BF_ENC(r,l,s,p[12]);
                BF_ENC(l,r,s,p[11]);
                BF_ENC(r,l,s,p[10]);
                BF_ENC(l,r,s,p[ 9]);
                BF_ENC(r,l,s,p[ 8]);
                BF_ENC(l,r,s,p[ 7]);
                BF_ENC(r,l,s,p[ 6]);
                BF_ENC(l,r,s,p[ 5]);
                BF_ENC(r,l,s,p[ 4]);
                BF_ENC(l,r,s,p[ 3]);
                BF_ENC(r,l,s,p[ 2]);
                BF_ENC(l,r,s,p[ 1]);
                r^=p[0];
                }
        data[1]=l&0xffffffff;
        data[0]=r&0xffffffff;
        }