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 /* 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 assert(in && out && key && ivec && num); 75 76 n = *num; 77 78 #if !defined(OPENSSL_SMALL_FOOTPRINT) 79 if (16%sizeof(size_t) == 0) do { /* always true actually */ 80 while (n && len) { 81 *(out++) = *(in++) ^ ivec[n]; 82 --len; 83 n = (n+1) % 16; 84 } 85 #ifdef __STRICT_ALIGNMENT 86 if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) 87 break; 88 #endif 89 while (len>=16) { 90 (*block)(ivec, ivec, key); 91 for (; n<16; n+=sizeof(size_t)) 92 *(size_t*)(out+n) = 93 *(size_t*)(in+n) ^ *(size_t*)(ivec+n); 94 len -= 16; 95 out += 16; 96 in += 16; 97 n = 0; 98 } 99 if (len) { 100 (*block)(ivec, ivec, key); 101 while (len--) { 102 out[n] = in[n] ^ ivec[n]; 103 ++n; 104 } 105 } 106 *num = n; 107 return; 108 } while(0); 109 /* the rest would be commonly eliminated by x86* compiler */ 110 #endif 111 while (l<len) { 112 if (n==0) { 113 (*block)(ivec, ivec, key); 114 } 115 out[l] = in[l] ^ ivec[n]; 116 ++l; 117 n = (n+1) % 16; 118 } 119 120 *num=n; 121 } 122