aes_ige.c revision 296341
1/* crypto/aes/aes_ige.c -*- mode:C; c-file-style: "eay" -*- */ 2/* ==================================================================== 3 * Copyright (c) 2006 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 "cryptlib.h" 53 54#include <openssl/aes.h> 55#include "aes_locl.h" 56 57#define N_WORDS (AES_BLOCK_SIZE / sizeof(unsigned long)) 58typedef struct { 59 unsigned long data[N_WORDS]; 60} aes_block_t; 61 62/* XXX: probably some better way to do this */ 63#if defined(__i386__) || defined(__x86_64__) 64# define UNALIGNED_MEMOPS_ARE_FAST 1 65#else 66# define UNALIGNED_MEMOPS_ARE_FAST 0 67#endif 68 69#if UNALIGNED_MEMOPS_ARE_FAST 70# define load_block(d, s) (d) = *(const aes_block_t *)(s) 71# define store_block(d, s) *(aes_block_t *)(d) = (s) 72#else 73# define load_block(d, s) memcpy((d).data, (s), AES_BLOCK_SIZE) 74# define store_block(d, s) memcpy((d), (s).data, AES_BLOCK_SIZE) 75#endif 76 77/* N.B. The IV for this mode is _twice_ the block size */ 78 79void AES_ige_encrypt(const unsigned char *in, unsigned char *out, 80 size_t length, const AES_KEY *key, 81 unsigned char *ivec, const int enc) 82{ 83 size_t n; 84 size_t len = length; 85 86 OPENSSL_assert(in && out && key && ivec); 87 OPENSSL_assert((AES_ENCRYPT == enc) || (AES_DECRYPT == enc)); 88 OPENSSL_assert((length % AES_BLOCK_SIZE) == 0); 89 90 len = length / AES_BLOCK_SIZE; 91 92 if (AES_ENCRYPT == enc) { 93 if (in != out && 94 (UNALIGNED_MEMOPS_ARE_FAST 95 || ((size_t)in | (size_t)out | (size_t)ivec) % sizeof(long) == 96 0)) { 97 aes_block_t *ivp = (aes_block_t *) ivec; 98 aes_block_t *iv2p = (aes_block_t *) (ivec + AES_BLOCK_SIZE); 99 100 while (len) { 101 aes_block_t *inp = (aes_block_t *) in; 102 aes_block_t *outp = (aes_block_t *) out; 103 104 for (n = 0; n < N_WORDS; ++n) 105 outp->data[n] = inp->data[n] ^ ivp->data[n]; 106 AES_encrypt((unsigned char *)outp->data, 107 (unsigned char *)outp->data, key); 108 for (n = 0; n < N_WORDS; ++n) 109 outp->data[n] ^= iv2p->data[n]; 110 ivp = outp; 111 iv2p = inp; 112 --len; 113 in += AES_BLOCK_SIZE; 114 out += AES_BLOCK_SIZE; 115 } 116 memcpy(ivec, ivp->data, AES_BLOCK_SIZE); 117 memcpy(ivec + AES_BLOCK_SIZE, iv2p->data, AES_BLOCK_SIZE); 118 } else { 119 aes_block_t tmp, tmp2; 120 aes_block_t iv; 121 aes_block_t iv2; 122 123 load_block(iv, ivec); 124 load_block(iv2, ivec + AES_BLOCK_SIZE); 125 126 while (len) { 127 load_block(tmp, in); 128 for (n = 0; n < N_WORDS; ++n) 129 tmp2.data[n] = tmp.data[n] ^ iv.data[n]; 130 AES_encrypt((unsigned char *)tmp2.data, 131 (unsigned char *)tmp2.data, key); 132 for (n = 0; n < N_WORDS; ++n) 133 tmp2.data[n] ^= iv2.data[n]; 134 store_block(out, tmp2); 135 iv = tmp2; 136 iv2 = tmp; 137 --len; 138 in += AES_BLOCK_SIZE; 139 out += AES_BLOCK_SIZE; 140 } 141 memcpy(ivec, iv.data, AES_BLOCK_SIZE); 142 memcpy(ivec + AES_BLOCK_SIZE, iv2.data, AES_BLOCK_SIZE); 143 } 144 } else { 145 if (in != out && 146 (UNALIGNED_MEMOPS_ARE_FAST 147 || ((size_t)in | (size_t)out | (size_t)ivec) % sizeof(long) == 148 0)) { 149 aes_block_t *ivp = (aes_block_t *) ivec; 150 aes_block_t *iv2p = (aes_block_t *) (ivec + AES_BLOCK_SIZE); 151 152 while (len) { 153 aes_block_t tmp; 154 aes_block_t *inp = (aes_block_t *) in; 155 aes_block_t *outp = (aes_block_t *) out; 156 157 for (n = 0; n < N_WORDS; ++n) 158 tmp.data[n] = inp->data[n] ^ iv2p->data[n]; 159 AES_decrypt((unsigned char *)tmp.data, 160 (unsigned char *)outp->data, key); 161 for (n = 0; n < N_WORDS; ++n) 162 outp->data[n] ^= ivp->data[n]; 163 ivp = inp; 164 iv2p = outp; 165 --len; 166 in += AES_BLOCK_SIZE; 167 out += AES_BLOCK_SIZE; 168 } 169 memcpy(ivec, ivp->data, AES_BLOCK_SIZE); 170 memcpy(ivec + AES_BLOCK_SIZE, iv2p->data, AES_BLOCK_SIZE); 171 } else { 172 aes_block_t tmp, tmp2; 173 aes_block_t iv; 174 aes_block_t iv2; 175 176 load_block(iv, ivec); 177 load_block(iv2, ivec + AES_BLOCK_SIZE); 178 179 while (len) { 180 load_block(tmp, in); 181 tmp2 = tmp; 182 for (n = 0; n < N_WORDS; ++n) 183 tmp.data[n] ^= iv2.data[n]; 184 AES_decrypt((unsigned char *)tmp.data, 185 (unsigned char *)tmp.data, key); 186 for (n = 0; n < N_WORDS; ++n) 187 tmp.data[n] ^= iv.data[n]; 188 store_block(out, tmp); 189 iv = tmp2; 190 iv2 = tmp; 191 --len; 192 in += AES_BLOCK_SIZE; 193 out += AES_BLOCK_SIZE; 194 } 195 memcpy(ivec, iv.data, AES_BLOCK_SIZE); 196 memcpy(ivec + AES_BLOCK_SIZE, iv2.data, AES_BLOCK_SIZE); 197 } 198 } 199} 200 201/* 202 * Note that its effectively impossible to do biIGE in anything other 203 * than a single pass, so no provision is made for chaining. 204 */ 205 206/* N.B. The IV for this mode is _four times_ the block size */ 207 208void AES_bi_ige_encrypt(const unsigned char *in, unsigned char *out, 209 size_t length, const AES_KEY *key, 210 const AES_KEY *key2, const unsigned char *ivec, 211 const int enc) 212{ 213 size_t n; 214 size_t len = length; 215 unsigned char tmp[AES_BLOCK_SIZE]; 216 unsigned char tmp2[AES_BLOCK_SIZE]; 217 unsigned char tmp3[AES_BLOCK_SIZE]; 218 unsigned char prev[AES_BLOCK_SIZE]; 219 const unsigned char *iv; 220 const unsigned char *iv2; 221 222 OPENSSL_assert(in && out && key && ivec); 223 OPENSSL_assert((AES_ENCRYPT == enc) || (AES_DECRYPT == enc)); 224 OPENSSL_assert((length % AES_BLOCK_SIZE) == 0); 225 226 if (AES_ENCRYPT == enc) { 227 /* 228 * XXX: Do a separate case for when in != out (strictly should check 229 * for overlap, too) 230 */ 231 232 /* First the forward pass */ 233 iv = ivec; 234 iv2 = ivec + AES_BLOCK_SIZE; 235 while (len >= AES_BLOCK_SIZE) { 236 for (n = 0; n < AES_BLOCK_SIZE; ++n) 237 out[n] = in[n] ^ iv[n]; 238 AES_encrypt(out, out, key); 239 for (n = 0; n < AES_BLOCK_SIZE; ++n) 240 out[n] ^= iv2[n]; 241 iv = out; 242 memcpy(prev, in, AES_BLOCK_SIZE); 243 iv2 = prev; 244 len -= AES_BLOCK_SIZE; 245 in += AES_BLOCK_SIZE; 246 out += AES_BLOCK_SIZE; 247 } 248 249 /* And now backwards */ 250 iv = ivec + AES_BLOCK_SIZE * 2; 251 iv2 = ivec + AES_BLOCK_SIZE * 3; 252 len = length; 253 while (len >= AES_BLOCK_SIZE) { 254 out -= AES_BLOCK_SIZE; 255 /* 256 * XXX: reduce copies by alternating between buffers 257 */ 258 memcpy(tmp, out, AES_BLOCK_SIZE); 259 for (n = 0; n < AES_BLOCK_SIZE; ++n) 260 out[n] ^= iv[n]; 261 /* 262 * hexdump(stdout, "out ^ iv", out, AES_BLOCK_SIZE); 263 */ 264 AES_encrypt(out, out, key); 265 /* 266 * hexdump(stdout,"enc", out, AES_BLOCK_SIZE); 267 */ 268 /* 269 * hexdump(stdout,"iv2", iv2, AES_BLOCK_SIZE); 270 */ 271 for (n = 0; n < AES_BLOCK_SIZE; ++n) 272 out[n] ^= iv2[n]; 273 /* 274 * hexdump(stdout,"out", out, AES_BLOCK_SIZE); 275 */ 276 iv = out; 277 memcpy(prev, tmp, AES_BLOCK_SIZE); 278 iv2 = prev; 279 len -= AES_BLOCK_SIZE; 280 } 281 } else { 282 /* First backwards */ 283 iv = ivec + AES_BLOCK_SIZE * 2; 284 iv2 = ivec + AES_BLOCK_SIZE * 3; 285 in += length; 286 out += length; 287 while (len >= AES_BLOCK_SIZE) { 288 in -= AES_BLOCK_SIZE; 289 out -= AES_BLOCK_SIZE; 290 memcpy(tmp, in, AES_BLOCK_SIZE); 291 memcpy(tmp2, in, AES_BLOCK_SIZE); 292 for (n = 0; n < AES_BLOCK_SIZE; ++n) 293 tmp[n] ^= iv2[n]; 294 AES_decrypt(tmp, out, key); 295 for (n = 0; n < AES_BLOCK_SIZE; ++n) 296 out[n] ^= iv[n]; 297 memcpy(tmp3, tmp2, AES_BLOCK_SIZE); 298 iv = tmp3; 299 iv2 = out; 300 len -= AES_BLOCK_SIZE; 301 } 302 303 /* And now forwards */ 304 iv = ivec; 305 iv2 = ivec + AES_BLOCK_SIZE; 306 len = length; 307 while (len >= AES_BLOCK_SIZE) { 308 memcpy(tmp, out, AES_BLOCK_SIZE); 309 memcpy(tmp2, out, AES_BLOCK_SIZE); 310 for (n = 0; n < AES_BLOCK_SIZE; ++n) 311 tmp[n] ^= iv2[n]; 312 AES_decrypt(tmp, out, key); 313 for (n = 0; n < AES_BLOCK_SIZE; ++n) 314 out[n] ^= iv[n]; 315 memcpy(tmp3, tmp2, AES_BLOCK_SIZE); 316 iv = tmp3; 317 iv2 = out; 318 len -= AES_BLOCK_SIZE; 319 in += AES_BLOCK_SIZE; 320 out += AES_BLOCK_SIZE; 321 } 322 } 323} 324