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 (at) 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 #include <openssl/type_check.h> 50 51 #include <assert.h> 52 53 #include "internal.h" 54 55 56 OPENSSL_COMPILE_ASSERT((16 % sizeof(size_t)) == 0, bad_size_t_size); 57 58 void CRYPTO_ofb128_encrypt(const uint8_t *in, uint8_t *out, size_t len, 59 const void *key, uint8_t ivec[16], int *num, 60 block128_f block) { 61 unsigned int n; 62 63 assert(in && out && key && ivec && num); 64 65 n = *num; 66 67 while (n && len) { 68 *(out++) = *(in++) ^ ivec[n]; 69 --len; 70 n = (n + 1) % 16; 71 } 72 73 #if STRICT_ALIGNMENT 74 if (((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) { 75 size_t l = 0; 76 while (l < len) { 77 if (n == 0) { 78 (*block)(ivec, ivec, key); 79 } 80 out[l] = in[l] ^ ivec[n]; 81 ++l; 82 n = (n + 1) % 16; 83 } 84 85 *num = n; 86 return; 87 } 88 #endif 89 90 while (len >= 16) { 91 (*block)(ivec, ivec, key); 92 for (; n < 16; n += sizeof(size_t)) { 93 *(size_t *)(out + n) = *(size_t *)(in + n) ^ *(size_t *)(ivec + n); 94 } 95 len -= 16; 96 out += 16; 97 in += 16; 98 n = 0; 99 } 100 if (len) { 101 (*block)(ivec, ivec, key); 102 while (len--) { 103 out[n] = in[n] ^ ivec[n]; 104 ++n; 105 } 106 } 107 *num = n; 108 } 109
