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#include <openssl/modes.h> 49 50#include <assert.h> 51#include <string.h> 52 53#include "internal.h" 54 55 56#ifndef STRICT_ALIGNMENT 57# define STRICT_ALIGNMENT 0 58#endif 59 60void CRYPTO_cbc128_encrypt(const uint8_t *in, uint8_t *out, size_t len, 61 const void *key, uint8_t ivec[16], 62 block128_f block) { 63 size_t n; 64 const uint8_t *iv = ivec; 65 66 assert(key != NULL && ivec != NULL); 67 assert(len == 0 || (in != NULL && out != NULL)); 68 69 if (STRICT_ALIGNMENT && 70 ((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) { 71 while (len >= 16) { 72 for (n = 0; n < 16; ++n) { 73 out[n] = in[n] ^ iv[n]; 74 } 75 (*block)(out, out, key); 76 iv = out; 77 len -= 16; 78 in += 16; 79 out += 16; 80 } 81 } else { 82 while (len >= 16) { 83 for (n = 0; n < 16; n += sizeof(size_t)) { 84 *(size_t *)(out + n) = *(size_t *)(in + n) ^ *(size_t *)(iv + n); 85 } 86 (*block)(out, out, key); 87 iv = out; 88 len -= 16; 89 in += 16; 90 out += 16; 91 } 92 } 93 94 while (len) { 95 for (n = 0; n < 16 && n < len; ++n) { 96 out[n] = in[n] ^ iv[n]; 97 } 98 for (; n < 16; ++n) { 99 out[n] = iv[n]; 100 } 101 (*block)(out, out, key); 102 iv = out; 103 if (len <= 16) { 104 break; 105 } 106 len -= 16; 107 in += 16; 108 out += 16; 109 } 110 111 memcpy(ivec, iv, 16); 112} 113 114void CRYPTO_cbc128_decrypt(const uint8_t *in, uint8_t *out, size_t len, 115 const void *key, uint8_t ivec[16], 116 block128_f block) { 117 size_t n; 118 union { 119 size_t t[16 / sizeof(size_t)]; 120 uint8_t c[16]; 121 } tmp; 122 123 assert(key != NULL && ivec != NULL); 124 assert(len == 0 || (in != NULL && out != NULL)); 125 126 const uintptr_t inptr = (uintptr_t) in; 127 const uintptr_t outptr = (uintptr_t) out; 128 /* If |in| and |out| alias, |in| must be ahead. */ 129 assert(inptr >= outptr || inptr + len <= outptr); 130 131 if ((inptr >= 32 && outptr <= inptr - 32) || inptr < outptr) { 132 /* If |out| is at least two blocks behind |in| or completely disjoint, there 133 * is no need to decrypt to a temporary block. */ 134 const uint8_t *iv = ivec; 135 136 if (STRICT_ALIGNMENT && 137 ((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) { 138 while (len >= 16) { 139 (*block)(in, out, key); 140 for (n = 0; n < 16; ++n) { 141 out[n] ^= iv[n]; 142 } 143 iv = in; 144 len -= 16; 145 in += 16; 146 out += 16; 147 } 148 } else if (16 % sizeof(size_t) == 0) { /* always true */ 149 while (len >= 16) { 150 size_t *out_t = (size_t *)out, *iv_t = (size_t *)iv; 151 152 (*block)(in, out, key); 153 for (n = 0; n < 16 / sizeof(size_t); n++) { 154 out_t[n] ^= iv_t[n]; 155 } 156 iv = in; 157 len -= 16; 158 in += 16; 159 out += 16; 160 } 161 } 162 memcpy(ivec, iv, 16); 163 } else { 164 /* |out| is less than two blocks behind |in|. Decrypting an input block 165 * directly to |out| would overwrite a ciphertext block before it is used as 166 * the next block's IV. Decrypt to a temporary block instead. */ 167 if (STRICT_ALIGNMENT && 168 ((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) { 169 uint8_t c; 170 while (len >= 16) { 171 (*block)(in, tmp.c, key); 172 for (n = 0; n < 16; ++n) { 173 c = in[n]; 174 out[n] = tmp.c[n] ^ ivec[n]; 175 ivec[n] = c; 176 } 177 len -= 16; 178 in += 16; 179 out += 16; 180 } 181 } else if (16 % sizeof(size_t) == 0) { /* always true */ 182 while (len >= 16) { 183 size_t c, *out_t = (size_t *)out, *ivec_t = (size_t *)ivec; 184 const size_t *in_t = (const size_t *)in; 185 186 (*block)(in, tmp.c, key); 187 for (n = 0; n < 16 / sizeof(size_t); n++) { 188 c = in_t[n]; 189 out_t[n] = tmp.t[n] ^ ivec_t[n]; 190 ivec_t[n] = c; 191 } 192 len -= 16; 193 in += 16; 194 out += 16; 195 } 196 } 197 } 198 199 while (len) { 200 uint8_t c; 201 (*block)(in, tmp.c, key); 202 for (n = 0; n < 16 && n < len; ++n) { 203 c = in[n]; 204 out[n] = tmp.c[n] ^ ivec[n]; 205 ivec[n] = c; 206 } 207 if (len <= 16) { 208 for (; n < 16; ++n) { 209 ivec[n] = in[n]; 210 } 211 break; 212 } 213 len -= 16; 214 in += 16; 215 out += 16; 216 } 217} 218