ofb128.c revision 1.1.1.1
1/* ==================================================================== 2 * Copyright (c) 2008 The OpenSSL Project. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in 13 * the documentation and/or other materials provided with the 14 * distribution. 15 * 16 * 3. All advertising materials mentioning features or use of this 17 * software must display the following acknowledgment: 18 * "This product includes software developed by the OpenSSL Project 19 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 20 * 21 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 22 * endorse or promote products derived from this software without 23 * prior written permission. For written permission, please contact 24 * openssl-core@openssl.org. 25 * 26 * 5. Products derived from this software may not be called "OpenSSL" 27 * nor may "OpenSSL" appear in their names without prior written 28 * permission of the OpenSSL Project. 29 * 30 * 6. Redistributions of any form whatsoever must retain the following 31 * acknowledgment: 32 * "This product includes software developed by the OpenSSL Project 33 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 34 * 35 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 36 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 37 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 38 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 39 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 40 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 41 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 42 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 43 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 44 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 45 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 46 * OF THE POSSIBILITY OF SUCH DAMAGE. 47 * ==================================================================== 48 * 49 */ 50 51#include "modes.h" 52#include <string.h> 53 54#ifndef MODES_DEBUG 55# ifndef NDEBUG 56# define NDEBUG 57# endif 58#endif 59#include <assert.h> 60 61#define STRICT_ALIGNMENT 62#if defined(__i386) || defined(__i386__) || \ 63 defined(__x86_64) || defined(__x86_64__) || \ 64 defined(_M_IX86) || defined(_M_AMD64) || defined(_M_X64) || \ 65 defined(__s390__) || defined(__s390x__) 66# undef STRICT_ALIGNMENT 67#endif 68 69/* The input and output encrypted as though 128bit ofb mode is being 70 * used. The extra state information to record how much of the 71 * 128bit block we have used is contained in *num; 72 */ 73void CRYPTO_ofb128_encrypt(const unsigned char *in, unsigned char *out, 74 size_t len, const void *key, 75 unsigned char ivec[16], int *num, 76 block128_f block) 77{ 78 unsigned int n; 79 size_t l=0; 80 81 assert(in && out && key && ivec && num); 82 83 n = *num; 84 85#if !defined(OPENSSL_SMALL_FOOTPRINT) 86 if (16%sizeof(size_t) == 0) do { /* always true actually */ 87 while (n && len) { 88 *(out++) = *(in++) ^ ivec[n]; 89 --len; 90 n = (n+1) % 16; 91 } 92#if defined(STRICT_ALIGNMENT) 93 if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) 94 break; 95#endif 96 while (len>=16) { 97 (*block)(ivec, ivec, key); 98 for (n=0; n<16; n+=sizeof(size_t)) 99 *(size_t*)(out+n) = 100 *(size_t*)(in+n) ^ *(size_t*)(ivec+n); 101 len -= 16; 102 out += 16; 103 in += 16; 104 } 105 n = 0; 106 if (len) { 107 (*block)(ivec, ivec, key); 108 while (len--) { 109 out[n] = in[n] ^ ivec[n]; 110 ++n; 111 } 112 } 113 *num = n; 114 return; 115 } while(0); 116 /* the rest would be commonly eliminated by x86* compiler */ 117#endif 118 while (l<len) { 119 if (n==0) { 120 (*block)(ivec, ivec, key); 121 } 122 out[l] = in[l] ^ ivec[n]; 123 ++l; 124 n = (n+1) % 16; 125 } 126 127 *num=n; 128} 129