1 /* $OpenBSD: ofb128.c,v 1.3 2014/06/12 15:49:30 deraadt Exp $ */ 2 /* ==================================================================== 3 * Copyright (c) 2008 The OpenSSL Project. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in 14 * the documentation and/or other materials provided with the 15 * distribution. 16 * 17 * 3. All advertising materials mentioning features or use of this 18 * software must display the following acknowledgment: 19 * "This product includes software developed by the OpenSSL Project 20 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 21 * 22 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 23 * endorse or promote products derived from this software without 24 * prior written permission. For written permission, please contact 25 * openssl-core@openssl.org. 26 * 27 * 5. Products derived from this software may not be called "OpenSSL" 28 * nor may "OpenSSL" appear in their names without prior written 29 * permission of the OpenSSL Project. 30 * 31 * 6. Redistributions of any form whatsoever must retain the following 32 * acknowledgment: 33 * "This product includes software developed by the OpenSSL Project 34 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 35 * 36 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 37 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 39 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 40 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 41 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 42 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 43 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 45 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 46 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 47 * OF THE POSSIBILITY OF SUCH DAMAGE. 48 * ==================================================================== 49 * 50 */ 51 52 #include <openssl/crypto.h> 53 #include "modes_lcl.h" 54 #include <string.h> 55 56 #ifndef MODES_DEBUG 57 # ifndef NDEBUG 58 # define NDEBUG 59 # endif 60 #endif 61 62 /* The input and output encrypted as though 128bit ofb mode is being 63 * used. The extra state information to record how much of the 64 * 128bit block we have used is contained in *num; 65 */ 66 void CRYPTO_ofb128_encrypt(const unsigned char *in, unsigned char *out, 67 size_t len, const void *key, 68 unsigned char ivec[16], int *num, 69 block128_f block) 70 { 71 unsigned int n; 72 size_t l=0; 73 74 n = *num; 75 76 #if !defined(OPENSSL_SMALL_FOOTPRINT) 77 if (16%sizeof(size_t) == 0) do { /* always true actually */ 78 while (n && len) { 79 *(out++) = *(in++) ^ ivec[n]; 80 --len; 81 n = (n+1) % 16; 82 } 83 #ifdef __STRICT_ALIGNMENT 84 if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) 85 break; 86 #endif 87 while (len>=16) { 88 (*block)(ivec, ivec, key); 89 for (; n<16; n+=sizeof(size_t)) 90 *(size_t*)(out+n) = 91 *(size_t*)(in+n) ^ *(size_t*)(ivec+n); 92 len -= 16; 93 out += 16; 94 in += 16; 95 n = 0; 96 } 97 if (len) { 98 (*block)(ivec, ivec, key); 99 while (len--) { 100 out[n] = in[n] ^ ivec[n]; 101 ++n; 102 } 103 } 104 *num = n; 105 return; 106 } while(0); 107 /* the rest would be commonly eliminated by x86* compiler */ 108 #endif 109 while (l<len) { 110 if (n==0) { 111 (*block)(ivec, ivec, key); 112 } 113 out[l] = in[l] ^ ivec[n]; 114 ++l; 115 n = (n+1) % 16; 116 } 117 118 *num=n; 119 } 120