www.pudn.com > speakfs72.zip > BF_OFB64.C, change:2002-01-05,size:4815b


/* crypto/bf/bf_ofb64.c */ 
/* Copyright (C) 1995-1997 Eric Young (eay@mincom.oz.au) 
 * All rights reserved. 
 * 
 * This package is an SSL implementation written 
 * by Eric Young (eay@mincom.oz.au). 
 * 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 (tjh@mincom.oz.au). 
 *  
 * 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 (eay@mincom.oz.au)" 
 *    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 (tjh@mincom.oz.au)" 
 *  
 * 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" 
 
/* The input and output encrypted as though 64bit ofb mode is being 
 * used.  The extra state information to record how much of the 
 * 64bit block we have used is contained in *num; 
 */ 
void BF_ofb64_encrypt(in, out, length, schedule, ivec, num) 
unsigned char *in; 
unsigned char *out; 
long length; 
BF_KEY *schedule; 
unsigned char *ivec; 
int *num; 
        { 
        register unsigned long v0,v1,t; 
        register int n= *num; 
        register long l=length; 
        unsigned char d[8]; 
        register char *dp; 
        unsigned long ti[2]; 
        unsigned char *iv; 
        int save=0; 
 
        iv=(unsigned char *)ivec; 
        n2l(iv,v0); 
        n2l(iv,v1); 
        ti[0]=v0; 
        ti[1]=v1; 
        dp=(char *)d; 
        l2n(v0,dp); 
        l2n(v1,dp); 
        while (l--) 
                { 
                if (n == 0) 
                        { 
                        BF_encrypt((unsigned long *)ti,schedule,BF_ENCRYPT); 
                        dp=(char *)d; 
                        t=ti[0]; l2n(t,dp); 
                        t=ti[1]; l2n(t,dp); 
                        save++; 
                        } 
                *(out++)= *(in++)^d[n]; 
                n=(n+1)&0x07; 
                } 
        if (save) 
                { 
                v0=ti[0]; 
                v1=ti[1]; 
                iv=(unsigned char *)ivec; 
                l2n(v0,iv); 
                l2n(v1,iv); 
                } 
        t=v0=v1=ti[0]=ti[1]=0; 
        *num=n; 
        }