155714Skris/* crypto/des/cfb_enc.c */ 255714Skris/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 355714Skris * All rights reserved. 455714Skris * 555714Skris * This package is an SSL implementation written 655714Skris * by Eric Young (eay@cryptsoft.com). 755714Skris * The implementation was written so as to conform with Netscapes SSL. 8296341Sdelphij * 955714Skris * This library is free for commercial and non-commercial use as long as 1055714Skris * the following conditions are aheared to. The following conditions 1155714Skris * apply to all code found in this distribution, be it the RC4, RSA, 1255714Skris * lhash, DES, etc., code; not just the SSL code. The SSL documentation 1355714Skris * included with this distribution is covered by the same copyright terms 1455714Skris * except that the holder is Tim Hudson (tjh@cryptsoft.com). 15296341Sdelphij * 1655714Skris * Copyright remains Eric Young's, and as such any Copyright notices in 1755714Skris * the code are not to be removed. 1855714Skris * If this package is used in a product, Eric Young should be given attribution 1955714Skris * as the author of the parts of the library used. 2055714Skris * This can be in the form of a textual message at program startup or 2155714Skris * in documentation (online or textual) provided with the package. 22296341Sdelphij * 2355714Skris * Redistribution and use in source and binary forms, with or without 2455714Skris * modification, are permitted provided that the following conditions 2555714Skris * are met: 2655714Skris * 1. Redistributions of source code must retain the copyright 2755714Skris * notice, this list of conditions and the following disclaimer. 2855714Skris * 2. Redistributions in binary form must reproduce the above copyright 2955714Skris * notice, this list of conditions and the following disclaimer in the 3055714Skris * documentation and/or other materials provided with the distribution. 3155714Skris * 3. All advertising materials mentioning features or use of this software 3255714Skris * must display the following acknowledgement: 3355714Skris * "This product includes cryptographic software written by 3455714Skris * Eric Young (eay@cryptsoft.com)" 3555714Skris * The word 'cryptographic' can be left out if the rouines from the library 3655714Skris * being used are not cryptographic related :-). 37296341Sdelphij * 4. If you include any Windows specific code (or a derivative thereof) from 3855714Skris * the apps directory (application code) you must include an acknowledgement: 3955714Skris * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 40296341Sdelphij * 4155714Skris * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 4255714Skris * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 4355714Skris * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 4455714Skris * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 4555714Skris * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 4655714Skris * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 4755714Skris * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 4855714Skris * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 4955714Skris * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 5055714Skris * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 5155714Skris * SUCH DAMAGE. 52296341Sdelphij * 5355714Skris * The licence and distribution terms for any publically available version or 5455714Skris * derivative of this code cannot be changed. i.e. this code cannot simply be 5555714Skris * copied and put under another distribution licence 5655714Skris * [including the GNU Public Licence.] 5755714Skris */ 5855714Skris 59127128Snectar#include "e_os.h" 6055714Skris#include "des_locl.h" 61160814Ssimon#include <assert.h> 6255714Skris 63296341Sdelphij/* 64296341Sdelphij * The input and output are loaded in multiples of 8 bits. What this means is 65296341Sdelphij * that if you hame numbits=12 and length=2 the first 12 bits will be 66296341Sdelphij * retrieved from the first byte and half the second. The second 12 bits 67296341Sdelphij * will come from the 3rd and half the 4th byte. 6855714Skris */ 69296341Sdelphij/* 70296341Sdelphij * Until Aug 1 2003 this function did not correctly implement CFB-r, so it 71296341Sdelphij * will not be compatible with any encryption prior to that date. Ben. 72296341Sdelphij */ 73109998Smarkmvoid DES_cfb_encrypt(const unsigned char *in, unsigned char *out, int numbits, 74296341Sdelphij long length, DES_key_schedule *schedule, 75296341Sdelphij DES_cblock *ivec, int enc) 76296341Sdelphij{ 77296341Sdelphij register DES_LONG d0, d1, v0, v1; 78296341Sdelphij register unsigned long l = length; 79296341Sdelphij register int num = numbits / 8, n = (numbits + 7) / 8, i, rem = 80296341Sdelphij numbits % 8; 81296341Sdelphij DES_LONG ti[2]; 82296341Sdelphij unsigned char *iv; 83160814Ssimon#ifndef L_ENDIAN 84296341Sdelphij unsigned char ovec[16]; 85160814Ssimon#else 86296341Sdelphij unsigned int sh[4]; 87296341Sdelphij unsigned char *ovec = (unsigned char *)sh; 8855714Skris 89296341Sdelphij /* I kind of count that compiler optimizes away this assertioni, */ 90296341Sdelphij assert(sizeof(sh[0]) == 4); /* as this holds true for all, */ 91296341Sdelphij /* but 16-bit platforms... */ 92296341Sdelphij 93160814Ssimon#endif 94160814Ssimon 95296341Sdelphij if (numbits <= 0 || numbits > 64) 96296341Sdelphij return; 97296341Sdelphij iv = &(*ivec)[0]; 98296341Sdelphij c2l(iv, v0); 99296341Sdelphij c2l(iv, v1); 100296341Sdelphij if (enc) { 101296341Sdelphij while (l >= (unsigned long)n) { 102296341Sdelphij l -= n; 103296341Sdelphij ti[0] = v0; 104296341Sdelphij ti[1] = v1; 105296341Sdelphij DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT); 106296341Sdelphij c2ln(in, d0, d1, n); 107296341Sdelphij in += n; 108296341Sdelphij d0 ^= ti[0]; 109296341Sdelphij d1 ^= ti[1]; 110296341Sdelphij l2cn(d0, d1, out, n); 111296341Sdelphij out += n; 112296341Sdelphij /* 113296341Sdelphij * 30-08-94 - eay - changed because l>>32 and l<<32 are bad under 114296341Sdelphij * gcc :-( 115296341Sdelphij */ 116296341Sdelphij if (numbits == 32) { 117296341Sdelphij v0 = v1; 118296341Sdelphij v1 = d0; 119296341Sdelphij } else if (numbits == 64) { 120296341Sdelphij v0 = d0; 121296341Sdelphij v1 = d1; 122296341Sdelphij } else { 123160814Ssimon#ifndef L_ENDIAN 124296341Sdelphij iv = &ovec[0]; 125296341Sdelphij l2c(v0, iv); 126296341Sdelphij l2c(v1, iv); 127296341Sdelphij l2c(d0, iv); 128296341Sdelphij l2c(d1, iv); 129160814Ssimon#else 130296341Sdelphij sh[0] = v0, sh[1] = v1, sh[2] = d0, sh[3] = d1; 131160814Ssimon#endif 132296341Sdelphij if (rem == 0) 133296341Sdelphij memmove(ovec, ovec + num, 8); 134296341Sdelphij else 135296341Sdelphij for (i = 0; i < 8; ++i) 136296341Sdelphij ovec[i] = ovec[i + num] << rem | 137296341Sdelphij ovec[i + num + 1] >> (8 - rem); 138160814Ssimon#ifdef L_ENDIAN 139296341Sdelphij v0 = sh[0], v1 = sh[1]; 140160814Ssimon#else 141296341Sdelphij iv = &ovec[0]; 142296341Sdelphij c2l(iv, v0); 143296341Sdelphij c2l(iv, v1); 144160814Ssimon#endif 145296341Sdelphij } 146296341Sdelphij } 147296341Sdelphij } else { 148296341Sdelphij while (l >= (unsigned long)n) { 149296341Sdelphij l -= n; 150296341Sdelphij ti[0] = v0; 151296341Sdelphij ti[1] = v1; 152296341Sdelphij DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT); 153296341Sdelphij c2ln(in, d0, d1, n); 154296341Sdelphij in += n; 155296341Sdelphij /* 156296341Sdelphij * 30-08-94 - eay - changed because l>>32 and l<<32 are bad under 157296341Sdelphij * gcc :-( 158296341Sdelphij */ 159296341Sdelphij if (numbits == 32) { 160296341Sdelphij v0 = v1; 161296341Sdelphij v1 = d0; 162296341Sdelphij } else if (numbits == 64) { 163296341Sdelphij v0 = d0; 164296341Sdelphij v1 = d1; 165296341Sdelphij } else { 166160814Ssimon#ifndef L_ENDIAN 167296341Sdelphij iv = &ovec[0]; 168296341Sdelphij l2c(v0, iv); 169296341Sdelphij l2c(v1, iv); 170296341Sdelphij l2c(d0, iv); 171296341Sdelphij l2c(d1, iv); 172160814Ssimon#else 173296341Sdelphij sh[0] = v0, sh[1] = v1, sh[2] = d0, sh[3] = d1; 174160814Ssimon#endif 175296341Sdelphij if (rem == 0) 176296341Sdelphij memmove(ovec, ovec + num, 8); 177296341Sdelphij else 178296341Sdelphij for (i = 0; i < 8; ++i) 179296341Sdelphij ovec[i] = ovec[i + num] << rem | 180296341Sdelphij ovec[i + num + 1] >> (8 - rem); 181160814Ssimon#ifdef L_ENDIAN 182296341Sdelphij v0 = sh[0], v1 = sh[1]; 183160814Ssimon#else 184296341Sdelphij iv = &ovec[0]; 185296341Sdelphij c2l(iv, v0); 186296341Sdelphij c2l(iv, v1); 187160814Ssimon#endif 188296341Sdelphij } 189296341Sdelphij d0 ^= ti[0]; 190296341Sdelphij d1 ^= ti[1]; 191296341Sdelphij l2cn(d0, d1, out, n); 192296341Sdelphij out += n; 193296341Sdelphij } 194296341Sdelphij } 195296341Sdelphij iv = &(*ivec)[0]; 196296341Sdelphij l2c(v0, iv); 197296341Sdelphij l2c(v1, iv); 198296341Sdelphij v0 = v1 = d0 = d1 = ti[0] = ti[1] = 0; 199296341Sdelphij} 200