1 /* crypto/des/cfb_enc.c */
\r/* Copyright (C) 1995-1997 Eric Young (eay@mincom.oz.au)
\r * All rights reserved.
\r *
\r * This package is an SSL implementation written
\r * by Eric Young (eay@mincom.oz.au).
\r * The implementation was written so as to conform with Netscapes SSL.
\r *
\r * This library is free for commercial and non-commercial use as long as
\r * the following conditions are aheared to. The following conditions
\r * apply to all code found in this distribution, be it the RC4, RSA,
\r * lhash, DES, etc., code; not just the SSL code. The SSL documentation
\r * included with this distribution is covered by the same copyright terms
\r * except that the holder is Tim Hudson (tjh@mincom.oz.au).
\r *
\r * Copyright remains Eric Young's, and as such any Copyright notices in
\r * the code are not to be removed.
\r * If this package is used in a product, Eric Young should be given attribution
\r * as the author of the parts of the library used.
\r * This can be in the form of a textual message at program startup or
\r * in documentation (online or textual) provided with the package.
\r *
\r * Redistribution and use in source and binary forms, with or without
\r * modification, are permitted provided that the following conditions
\r * are met:
\r * 1. Redistributions of source code must retain the copyright
\r * notice, this list of conditions and the following disclaimer.
\r * 2. Redistributions in binary form must reproduce the above copyright
\r * notice, this list of conditions and the following disclaimer in the
\r * documentation and/or other materials provided with the distribution.
\r * 3. All advertising materials mentioning features or use of this software
\r * must display the following acknowledgement:
\r * "This product includes cryptographic software written by
\r * Eric Young (eay@mincom.oz.au)"
\r * The word 'cryptographic' can be left out if the rouines from the library
\r * being used are not cryptographic related :-).
\r * 4. If you include any Windows specific code (or a derivative thereof) from
\r * the apps directory (application code) you must include an acknowledgement:
\r * "This product includes software written by Tim Hudson (tjh@mincom.oz.au)"
\r *
\r * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
\r * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
\r * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
\r * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
\r * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
\r * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
\r * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
\r * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
\r * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
\r * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
\r * SUCH DAMAGE.
\r *
\r * The licence and distribution terms for any publically available version or
\r * derivative of this code cannot be changed. i.e. this code cannot simply be
\r * copied and put under another distribution licence
\r * [including the GNU Public Licence.]
\r */
\r\r#include "des_locl.h"
\r\r/* The input and output are loaded in multiples of 8 bits.
\r * What this means is that if you hame numbits=12 and length=2
\r * the first 12 bits will be retrieved from the first byte and half
\r * the second. The second 12 bits will come from the 3rd and half the 4th
\r * byte.
\r */
\rvoid des_cfb_encrypt(in, out, numbits, length, schedule, ivec, encrypt)
\runsigned char *in;
\runsigned char *out;
\rint numbits;
\rlong length;
\rdes_key_schedule schedule;
\rdes_cblock (*ivec);
\rint encrypt;
\r {
\r register DES_LONG d0,d1,v0,v1,n=(numbits+7)/8;
\r register DES_LONG mask0,mask1;
\r register unsigned long l=length;
\r register int num=numbits;
\r DES_LONG ti[2];
\r unsigned char *iv;
\r\r if (num > 64) return;
\r if (num > 32)
\r {
\r mask0=0xffffffffL;
\r if (num == 64)
\r mask1=mask0;
\r else mask1=(1L<<(num-32))-1;
\r }
\r else
\r {
\r if (num == 32)
\r mask0=0xffffffffL;
\r else mask0=(1L<<num)-1;
\r mask1=0x00000000;
\r }
\r\r iv=(unsigned char *)ivec;
\r c2l(iv,v0);
\r c2l(iv,v1);
\r if (encrypt)
\r {
\r while (l >= n)
\r {
\r l-=n;
\r ti[0]=v0;
\r ti[1]=v1;
\r des_encrypt((DES_LONG *)ti,schedule,DES_ENCRYPT);
\r c2ln(in,d0,d1,n);
\r in+=n;
\r d0=(d0^ti[0])&mask0;
\r d1=(d1^ti[1])&mask1;
\r l2cn(d0,d1,out,n);
\r out+=n;
\r /* 30-08-94 - eay - changed because l>>32 and
\r * l<<32 are bad under gcc :-( */
\r if (num == 32)
\r { v0=v1; v1=d0; }
\r else if (num == 64)
\r { v0=d0; v1=d1; }
\r else if (num > 32) /* && num != 64 */
\r {
\r v0=((v1>>(num-32))|(d0<<(64-num)))&0xffffffffL;
\r v1=((d0>>(num-32))|(d1<<(64-num)))&0xffffffffL;
\r }
\r else /* num < 32 */
\r {
\r v0=((v0>>num)|(v1<<(32-num)))&0xffffffffL;
\r v1=((v1>>num)|(d0<<(32-num)))&0xffffffffL;
\r }
\r }
\r }
\r else
\r {
\r while (l >= n)
\r {
\r l-=n;
\r ti[0]=v0;
\r ti[1]=v1;
\r des_encrypt((DES_LONG *)ti,schedule,DES_ENCRYPT);
\r c2ln(in,d0,d1,n);
\r in+=n;
\r /* 30-08-94 - eay - changed because l>>32 and
\r * l<<32 are bad under gcc :-( */
\r if (num == 32)
\r { v0=v1; v1=d0; }
\r else if (num == 64)
\r { v0=d0; v1=d1; }
\r else if (num > 32) /* && num != 64 */
\r {
\r v0=((v1>>(num-32))|(d0<<(64-num)))&0xffffffffL;
\r v1=((d0>>(num-32))|(d1<<(64-num)))&0xffffffffL;
\r }
\r else /* num < 32 */
\r {
\r v0=((v0>>num)|(v1<<(32-num)))&0xffffffffL;
\r v1=((v1>>num)|(d0<<(32-num)))&0xffffffffL;
\r }
\r d0=(d0^ti[0])&mask0;
\r d1=(d1^ti[1])&mask1;
\r l2cn(d0,d1,out,n);
\r out+=n;
\r }
\r }
\r iv=(unsigned char *)ivec;
\r l2c(v0,iv);
\r l2c(v1,iv);
\r v0=v1=d0=d1=ti[0]=ti[1]=0;
\r }
\r\r
projects / cyrus-sasl.git / blob