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 <openssl/crypto.h> 52#include "modes_lcl.h" 53#include <string.h> 54 55#ifndef MODES_DEBUG 56# ifndef NDEBUG 57# define NDEBUG 58# endif 59#endif 60#include <assert.h> 61 62/* 63 * The input and output encrypted as though 128bit ofb mode is being used. 64 * The extra state information to record how much of the 128bit block we have 65 * used is contained in *num; 66 */ 67void CRYPTO_ofb128_encrypt(const unsigned char *in, unsigned char *out, 68 size_t len, const void *key, 69 unsigned char ivec[16], int *num, block128_f block) 70{ 71 unsigned int n; 72 size_t l = 0; 73 74 assert(in && out && key && ivec && num); 75 76 n = *num; 77 78#if !defined(OPENSSL_SMALL_FOOTPRINT) 79 if (16 % sizeof(size_t) == 0) { /* always true actually */ 80 do { 81 while (n && len) { 82 *(out++) = *(in++) ^ ivec[n]; 83 --len; 84 n = (n + 1) % 16; 85 } 86# if defined(STRICT_ALIGNMENT) 87 if (((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 88 0) 89 break; 90# endif 91 while (len >= 16) { 92 (*block) (ivec, ivec, key); 93 for (; n < 16; n += sizeof(size_t)) 94 *(size_t *)(out + n) = 95 *(size_t *)(in + n) ^ *(size_t *)(ivec + n); 96 len -= 16; 97 out += 16; 98 in += 16; 99 n = 0; 100 } 101 if (len) { 102 (*block) (ivec, ivec, key); 103 while (len--) { 104 out[n] = in[n] ^ ivec[n]; 105 ++n; 106 } 107 } 108 *num = n; 109 return; 110 } while (0); 111 } 112 /* the rest would be commonly eliminated by x86* compiler */ 113#endif 114 while (l < len) { 115 if (n == 0) { 116 (*block) (ivec, ivec, key); 117 } 118 out[l] = in[l] ^ ivec[n]; 119 ++l; 120 n = (n + 1) % 16; 121 } 122 123 *num = n; 124} 125