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. 8280304Sjkim * 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). 15280304Sjkim * 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. 22280304Sjkim * 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 :-). 37280304Sjkim * 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)" 40280304Sjkim * 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. 52280304Sjkim * 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 63280304Sjkim/* 64280304Sjkim * The input and output are loaded in multiples of 8 bits. What this means is 65280304Sjkim * that if you hame numbits=12 and length=2 the first 12 bits will be 66280304Sjkim * retrieved from the first byte and half the second. The second 12 bits 67280304Sjkim * will come from the 3rd and half the 4th byte. 6855714Skris */ 69280304Sjkim/* 70280304Sjkim * Until Aug 1 2003 this function did not correctly implement CFB-r, so it 71280304Sjkim * will not be compatible with any encryption prior to that date. Ben. 72280304Sjkim */ 73109998Smarkmvoid DES_cfb_encrypt(const unsigned char *in, unsigned char *out, int numbits, 74280304Sjkim long length, DES_key_schedule *schedule, 75280304Sjkim DES_cblock *ivec, int enc) 76280304Sjkim{ 77280304Sjkim register DES_LONG d0, d1, v0, v1; 78280304Sjkim register unsigned long l = length; 79280304Sjkim register int num = numbits / 8, n = (numbits + 7) / 8, i, rem = 80280304Sjkim numbits % 8; 81280304Sjkim DES_LONG ti[2]; 82280304Sjkim unsigned char *iv; 83160814Ssimon#ifndef L_ENDIAN 84280304Sjkim unsigned char ovec[16]; 85160814Ssimon#else 86280304Sjkim unsigned int sh[4]; 87280304Sjkim unsigned char *ovec = (unsigned char *)sh; 8855714Skris 89280304Sjkim /* I kind of count that compiler optimizes away this assertioni, */ 90280304Sjkim assert(sizeof(sh[0]) == 4); /* as this holds true for all, */ 91280304Sjkim /* but 16-bit platforms... */ 92280304Sjkim 93160814Ssimon#endif 94160814Ssimon 95280304Sjkim if (numbits <= 0 || numbits > 64) 96280304Sjkim return; 97280304Sjkim iv = &(*ivec)[0]; 98280304Sjkim c2l(iv, v0); 99280304Sjkim c2l(iv, v1); 100280304Sjkim if (enc) { 101280304Sjkim while (l >= (unsigned long)n) { 102280304Sjkim l -= n; 103280304Sjkim ti[0] = v0; 104280304Sjkim ti[1] = v1; 105280304Sjkim DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT); 106280304Sjkim c2ln(in, d0, d1, n); 107280304Sjkim in += n; 108280304Sjkim d0 ^= ti[0]; 109280304Sjkim d1 ^= ti[1]; 110280304Sjkim l2cn(d0, d1, out, n); 111280304Sjkim out += n; 112280304Sjkim /* 113280304Sjkim * 30-08-94 - eay - changed because l>>32 and l<<32 are bad under 114280304Sjkim * gcc :-( 115280304Sjkim */ 116280304Sjkim if (numbits == 32) { 117280304Sjkim v0 = v1; 118280304Sjkim v1 = d0; 119280304Sjkim } else if (numbits == 64) { 120280304Sjkim v0 = d0; 121280304Sjkim v1 = d1; 122280304Sjkim } else { 123160814Ssimon#ifndef L_ENDIAN 124280304Sjkim iv = &ovec[0]; 125280304Sjkim l2c(v0, iv); 126280304Sjkim l2c(v1, iv); 127280304Sjkim l2c(d0, iv); 128280304Sjkim l2c(d1, iv); 129160814Ssimon#else 130280304Sjkim sh[0] = v0, sh[1] = v1, sh[2] = d0, sh[3] = d1; 131160814Ssimon#endif 132280304Sjkim if (rem == 0) 133280304Sjkim memmove(ovec, ovec + num, 8); 134280304Sjkim else 135280304Sjkim for (i = 0; i < 8; ++i) 136280304Sjkim ovec[i] = ovec[i + num] << rem | 137280304Sjkim ovec[i + num + 1] >> (8 - rem); 138160814Ssimon#ifdef L_ENDIAN 139280304Sjkim v0 = sh[0], v1 = sh[1]; 140160814Ssimon#else 141280304Sjkim iv = &ovec[0]; 142280304Sjkim c2l(iv, v0); 143280304Sjkim c2l(iv, v1); 144160814Ssimon#endif 145280304Sjkim } 146280304Sjkim } 147280304Sjkim } else { 148280304Sjkim while (l >= (unsigned long)n) { 149280304Sjkim l -= n; 150280304Sjkim ti[0] = v0; 151280304Sjkim ti[1] = v1; 152280304Sjkim DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT); 153280304Sjkim c2ln(in, d0, d1, n); 154280304Sjkim in += n; 155280304Sjkim /* 156280304Sjkim * 30-08-94 - eay - changed because l>>32 and l<<32 are bad under 157280304Sjkim * gcc :-( 158280304Sjkim */ 159280304Sjkim if (numbits == 32) { 160280304Sjkim v0 = v1; 161280304Sjkim v1 = d0; 162280304Sjkim } else if (numbits == 64) { 163280304Sjkim v0 = d0; 164280304Sjkim v1 = d1; 165280304Sjkim } else { 166160814Ssimon#ifndef L_ENDIAN 167280304Sjkim iv = &ovec[0]; 168280304Sjkim l2c(v0, iv); 169280304Sjkim l2c(v1, iv); 170280304Sjkim l2c(d0, iv); 171280304Sjkim l2c(d1, iv); 172160814Ssimon#else 173280304Sjkim sh[0] = v0, sh[1] = v1, sh[2] = d0, sh[3] = d1; 174160814Ssimon#endif 175280304Sjkim if (rem == 0) 176280304Sjkim memmove(ovec, ovec + num, 8); 177280304Sjkim else 178280304Sjkim for (i = 0; i < 8; ++i) 179280304Sjkim ovec[i] = ovec[i + num] << rem | 180280304Sjkim ovec[i + num + 1] >> (8 - rem); 181160814Ssimon#ifdef L_ENDIAN 182280304Sjkim v0 = sh[0], v1 = sh[1]; 183160814Ssimon#else 184280304Sjkim iv = &ovec[0]; 185280304Sjkim c2l(iv, v0); 186280304Sjkim c2l(iv, v1); 187160814Ssimon#endif 188280304Sjkim } 189280304Sjkim d0 ^= ti[0]; 190280304Sjkim d1 ^= ti[1]; 191280304Sjkim l2cn(d0, d1, out, n); 192280304Sjkim out += n; 193280304Sjkim } 194280304Sjkim } 195280304Sjkim iv = &(*ivec)[0]; 196280304Sjkim l2c(v0, iv); 197280304Sjkim l2c(v1, iv); 198280304Sjkim v0 = v1 = d0 = d1 = ti[0] = ti[1] = 0; 199280304Sjkim} 200