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 (at) 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)) 58 typedef 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 79 void 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 { 94 if (in != out && 95 (UNALIGNED_MEMOPS_ARE_FAST || ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(long)==0)) 96 { 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 { 102 aes_block_t *inp = (aes_block_t *)in; 103 aes_block_t *outp = (aes_block_t *)out; 104 105 for(n=0 ; n < N_WORDS; ++n) 106 outp->data[n] = inp->data[n] ^ ivp->data[n]; 107 AES_encrypt((unsigned char *)outp->data, (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 } 119 else 120 { 121 aes_block_t tmp, tmp2; 122 aes_block_t iv; 123 aes_block_t iv2; 124 125 load_block(iv, ivec); 126 load_block(iv2, ivec + AES_BLOCK_SIZE); 127 128 while (len) 129 { 130 load_block(tmp, in); 131 for(n=0 ; n < N_WORDS; ++n) 132 tmp2.data[n] = tmp.data[n] ^ iv.data[n]; 133 AES_encrypt((unsigned char *)tmp2.data, (unsigned char *)tmp2.data, key); 134 for(n=0 ; n < N_WORDS; ++n) 135 tmp2.data[n] ^= iv2.data[n]; 136 store_block(out, tmp2); 137 iv = tmp2; 138 iv2 = tmp; 139 --len; 140 in += AES_BLOCK_SIZE; 141 out += AES_BLOCK_SIZE; 142 } 143 memcpy(ivec, iv.data, AES_BLOCK_SIZE); 144 memcpy(ivec + AES_BLOCK_SIZE, iv2.data, AES_BLOCK_SIZE); 145 } 146 } 147 else 148 { 149 if (in != out && 150 (UNALIGNED_MEMOPS_ARE_FAST || ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(long)==0)) 151 { 152 aes_block_t *ivp = (aes_block_t *)ivec; 153 aes_block_t *iv2p = (aes_block_t *)(ivec + AES_BLOCK_SIZE); 154 155 while (len) 156 { 157 aes_block_t tmp; 158 aes_block_t *inp = (aes_block_t *)in; 159 aes_block_t *outp = (aes_block_t *)out; 160 161 for(n=0 ; n < N_WORDS; ++n) 162 tmp.data[n] = inp->data[n] ^ iv2p->data[n]; 163 AES_decrypt((unsigned char *)tmp.data, (unsigned char *)outp->data, key); 164 for(n=0 ; n < N_WORDS; ++n) 165 outp->data[n] ^= ivp->data[n]; 166 ivp = inp; 167 iv2p = outp; 168 --len; 169 in += AES_BLOCK_SIZE; 170 out += AES_BLOCK_SIZE; 171 } 172 memcpy(ivec, ivp->data, AES_BLOCK_SIZE); 173 memcpy(ivec + AES_BLOCK_SIZE, iv2p->data, AES_BLOCK_SIZE); 174 } 175 else 176 { 177 aes_block_t tmp, tmp2; 178 aes_block_t iv; 179 aes_block_t iv2; 180 181 load_block(iv, ivec); 182 load_block(iv2, ivec + AES_BLOCK_SIZE); 183 184 while (len) 185 { 186 load_block(tmp, in); 187 tmp2 = tmp; 188 for(n=0 ; n < N_WORDS; ++n) 189 tmp.data[n] ^= iv2.data[n]; 190 AES_decrypt((unsigned char *)tmp.data, (unsigned char *)tmp.data, key); 191 for(n=0 ; n < N_WORDS; ++n) 192 tmp.data[n] ^= iv.data[n]; 193 store_block(out, tmp); 194 iv = tmp2; 195 iv2 = tmp; 196 --len; 197 in += AES_BLOCK_SIZE; 198 out += AES_BLOCK_SIZE; 199 } 200 memcpy(ivec, iv.data, AES_BLOCK_SIZE); 201 memcpy(ivec + AES_BLOCK_SIZE, iv2.data, AES_BLOCK_SIZE); 202 } 203 } 204 } 205 206 /* 207 * Note that its effectively impossible to do biIGE in anything other 208 * than a single pass, so no provision is made for chaining. 209 */ 210 211 /* N.B. The IV for this mode is _four times_ the block size */ 212 213 void AES_bi_ige_encrypt(const unsigned char *in, unsigned char *out, 214 size_t length, const AES_KEY *key, 215 const AES_KEY *key2, const unsigned char *ivec, 216 const int enc) 217 { 218 size_t n; 219 size_t len = length; 220 unsigned char tmp[AES_BLOCK_SIZE]; 221 unsigned char tmp2[AES_BLOCK_SIZE]; 222 unsigned char tmp3[AES_BLOCK_SIZE]; 223 unsigned char prev[AES_BLOCK_SIZE]; 224 const unsigned char *iv; 225 const unsigned char *iv2; 226 227 OPENSSL_assert(in && out && key && ivec); 228 OPENSSL_assert((AES_ENCRYPT == enc)||(AES_DECRYPT == enc)); 229 OPENSSL_assert((length%AES_BLOCK_SIZE) == 0); 230 231 if (AES_ENCRYPT == enc) 232 { 233 /* XXX: Do a separate case for when in != out (strictly should 234 check for overlap, too) */ 235 236 /* First the forward pass */ 237 iv = ivec; 238 iv2 = ivec + AES_BLOCK_SIZE; 239 while (len >= AES_BLOCK_SIZE) 240 { 241 for(n=0 ; n < AES_BLOCK_SIZE ; ++n) 242 out[n] = in[n] ^ iv[n]; 243 AES_encrypt(out, out, key); 244 for(n=0 ; n < AES_BLOCK_SIZE ; ++n) 245 out[n] ^= iv2[n]; 246 iv = out; 247 memcpy(prev, in, AES_BLOCK_SIZE); 248 iv2 = prev; 249 len -= AES_BLOCK_SIZE; 250 in += AES_BLOCK_SIZE; 251 out += AES_BLOCK_SIZE; 252 } 253 254 /* And now backwards */ 255 iv = ivec + AES_BLOCK_SIZE*2; 256 iv2 = ivec + AES_BLOCK_SIZE*3; 257 len = length; 258 while(len >= AES_BLOCK_SIZE) 259 { 260 out -= AES_BLOCK_SIZE; 261 /* XXX: reduce copies by alternating between buffers */ 262 memcpy(tmp, out, AES_BLOCK_SIZE); 263 for(n=0 ; n < AES_BLOCK_SIZE ; ++n) 264 out[n] ^= iv[n]; 265 /* hexdump(stdout, "out ^ iv", out, AES_BLOCK_SIZE); */ 266 AES_encrypt(out, out, key); 267 /* hexdump(stdout,"enc", out, AES_BLOCK_SIZE); */ 268 /* hexdump(stdout,"iv2", iv2, AES_BLOCK_SIZE); */ 269 for(n=0 ; n < AES_BLOCK_SIZE ; ++n) 270 out[n] ^= iv2[n]; 271 /* hexdump(stdout,"out", out, AES_BLOCK_SIZE); */ 272 iv = out; 273 memcpy(prev, tmp, AES_BLOCK_SIZE); 274 iv2 = prev; 275 len -= AES_BLOCK_SIZE; 276 } 277 } 278 else 279 { 280 /* First backwards */ 281 iv = ivec + AES_BLOCK_SIZE*2; 282 iv2 = ivec + AES_BLOCK_SIZE*3; 283 in += length; 284 out += length; 285 while (len >= AES_BLOCK_SIZE) 286 { 287 in -= AES_BLOCK_SIZE; 288 out -= AES_BLOCK_SIZE; 289 memcpy(tmp, in, AES_BLOCK_SIZE); 290 memcpy(tmp2, in, AES_BLOCK_SIZE); 291 for(n=0 ; n < AES_BLOCK_SIZE ; ++n) 292 tmp[n] ^= iv2[n]; 293 AES_decrypt(tmp, out, key); 294 for(n=0 ; n < AES_BLOCK_SIZE ; ++n) 295 out[n] ^= iv[n]; 296 memcpy(tmp3, tmp2, AES_BLOCK_SIZE); 297 iv = tmp3; 298 iv2 = out; 299 len -= AES_BLOCK_SIZE; 300 } 301 302 /* And now forwards */ 303 iv = ivec; 304 iv2 = ivec + AES_BLOCK_SIZE; 305 len = length; 306 while (len >= AES_BLOCK_SIZE) 307 { 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
