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. 8280297Sjkim * 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). 15280297Sjkim * 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. 22280297Sjkim * 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 :-). 37280297Sjkim * 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)" 40280297Sjkim * 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. 52280297Sjkim * 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 63280297Sjkim/* 64280297Sjkim * The input and output are loaded in multiples of 8 bits. What this means is 65280297Sjkim * that if you hame numbits=12 and length=2 the first 12 bits will be 66280297Sjkim * retrieved from the first byte and half the second. The second 12 bits 67280297Sjkim * will come from the 3rd and half the 4th byte. 6855714Skris */ 69280297Sjkim/* 70280297Sjkim * Until Aug 1 2003 this function did not correctly implement CFB-r, so it 71280297Sjkim * will not be compatible with any encryption prior to that date. Ben. 72280297Sjkim */ 73109998Smarkmvoid DES_cfb_encrypt(const unsigned char *in, unsigned char *out, int numbits, 74280297Sjkim long length, DES_key_schedule *schedule, 75280297Sjkim DES_cblock *ivec, int enc) 76280297Sjkim{ 77280297Sjkim register DES_LONG d0, d1, v0, v1; 78280297Sjkim register unsigned long l = length; 79280297Sjkim register int num = numbits / 8, n = (numbits + 7) / 8, i, rem = 80280297Sjkim numbits % 8; 81280297Sjkim DES_LONG ti[2]; 82280297Sjkim unsigned char *iv; 83160814Ssimon#ifndef L_ENDIAN 84280297Sjkim unsigned char ovec[16]; 85160814Ssimon#else 86280297Sjkim unsigned int sh[4]; 87280297Sjkim unsigned char *ovec = (unsigned char *)sh; 8855714Skris 89280297Sjkim /* I kind of count that compiler optimizes away this assertioni, */ 90280297Sjkim assert(sizeof(sh[0]) == 4); /* as this holds true for all, */ 91280297Sjkim /* but 16-bit platforms... */ 92280297Sjkim 93160814Ssimon#endif 94160814Ssimon 95280297Sjkim if (numbits <= 0 || numbits > 64) 96280297Sjkim return; 97280297Sjkim iv = &(*ivec)[0]; 98280297Sjkim c2l(iv, v0); 99280297Sjkim c2l(iv, v1); 100280297Sjkim if (enc) { 101280297Sjkim while (l >= (unsigned long)n) { 102280297Sjkim l -= n; 103280297Sjkim ti[0] = v0; 104280297Sjkim ti[1] = v1; 105280297Sjkim DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT); 106280297Sjkim c2ln(in, d0, d1, n); 107280297Sjkim in += n; 108280297Sjkim d0 ^= ti[0]; 109280297Sjkim d1 ^= ti[1]; 110280297Sjkim l2cn(d0, d1, out, n); 111280297Sjkim out += n; 112280297Sjkim /* 113280297Sjkim * 30-08-94 - eay - changed because l>>32 and l<<32 are bad under 114280297Sjkim * gcc :-( 115280297Sjkim */ 116280297Sjkim if (numbits == 32) { 117280297Sjkim v0 = v1; 118280297Sjkim v1 = d0; 119280297Sjkim } else if (numbits == 64) { 120280297Sjkim v0 = d0; 121280297Sjkim v1 = d1; 122280297Sjkim } else { 123160814Ssimon#ifndef L_ENDIAN 124280297Sjkim iv = &ovec[0]; 125280297Sjkim l2c(v0, iv); 126280297Sjkim l2c(v1, iv); 127280297Sjkim l2c(d0, iv); 128280297Sjkim l2c(d1, iv); 129160814Ssimon#else 130280297Sjkim sh[0] = v0, sh[1] = v1, sh[2] = d0, sh[3] = d1; 131160814Ssimon#endif 132280297Sjkim if (rem == 0) 133280297Sjkim memmove(ovec, ovec + num, 8); 134280297Sjkim else 135280297Sjkim for (i = 0; i < 8; ++i) 136280297Sjkim ovec[i] = ovec[i + num] << rem | 137280297Sjkim ovec[i + num + 1] >> (8 - rem); 138160814Ssimon#ifdef L_ENDIAN 139280297Sjkim v0 = sh[0], v1 = sh[1]; 140160814Ssimon#else 141280297Sjkim iv = &ovec[0]; 142280297Sjkim c2l(iv, v0); 143280297Sjkim c2l(iv, v1); 144160814Ssimon#endif 145280297Sjkim } 146280297Sjkim } 147280297Sjkim } else { 148280297Sjkim while (l >= (unsigned long)n) { 149280297Sjkim l -= n; 150280297Sjkim ti[0] = v0; 151280297Sjkim ti[1] = v1; 152280297Sjkim DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT); 153280297Sjkim c2ln(in, d0, d1, n); 154280297Sjkim in += n; 155280297Sjkim /* 156280297Sjkim * 30-08-94 - eay - changed because l>>32 and l<<32 are bad under 157280297Sjkim * gcc :-( 158280297Sjkim */ 159280297Sjkim if (numbits == 32) { 160280297Sjkim v0 = v1; 161280297Sjkim v1 = d0; 162280297Sjkim } else if (numbits == 64) { 163280297Sjkim v0 = d0; 164280297Sjkim v1 = d1; 165280297Sjkim } else { 166160814Ssimon#ifndef L_ENDIAN 167280297Sjkim iv = &ovec[0]; 168280297Sjkim l2c(v0, iv); 169280297Sjkim l2c(v1, iv); 170280297Sjkim l2c(d0, iv); 171280297Sjkim l2c(d1, iv); 172160814Ssimon#else 173280297Sjkim sh[0] = v0, sh[1] = v1, sh[2] = d0, sh[3] = d1; 174160814Ssimon#endif 175280297Sjkim if (rem == 0) 176280297Sjkim memmove(ovec, ovec + num, 8); 177280297Sjkim else 178280297Sjkim for (i = 0; i < 8; ++i) 179280297Sjkim ovec[i] = ovec[i + num] << rem | 180280297Sjkim ovec[i + num + 1] >> (8 - rem); 181160814Ssimon#ifdef L_ENDIAN 182280297Sjkim v0 = sh[0], v1 = sh[1]; 183160814Ssimon#else 184280297Sjkim iv = &ovec[0]; 185280297Sjkim c2l(iv, v0); 186280297Sjkim c2l(iv, v1); 187160814Ssimon#endif 188280297Sjkim } 189280297Sjkim d0 ^= ti[0]; 190280297Sjkim d1 ^= ti[1]; 191280297Sjkim l2cn(d0, d1, out, n); 192280297Sjkim out += n; 193280297Sjkim } 194280297Sjkim } 195280297Sjkim iv = &(*ivec)[0]; 196280297Sjkim l2c(v0, iv); 197280297Sjkim l2c(v1, iv); 198280297Sjkim v0 = v1 = d0 = d1 = ti[0] = ti[1] = 0; 199280297Sjkim} 200