crypto.c revision 1.22
1/* $OpenBSD: crypto.c,v 1.22 2004/06/14 09:55:41 ho Exp $ */ 2/* $EOM: crypto.c,v 1.32 2000/03/07 20:08:51 niklas Exp $ */ 3 4/* 5 * Copyright (c) 1998 Niels Provos. All rights reserved. 6 * Copyright (c) 1999, 2000 Niklas Hallqvist. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29/* 30 * This code was written under funding by Ericsson Radio Systems. 31 */ 32 33#include <sys/param.h> 34#include <stdlib.h> 35#include <string.h> 36 37#include "sysdep.h" 38 39#include "crypto.h" 40#include "log.h" 41 42enum cryptoerr des1_init(struct keystate *, u_int8_t *, u_int16_t); 43enum cryptoerr des3_init(struct keystate *, u_int8_t *, u_int16_t); 44enum cryptoerr blf_init(struct keystate *, u_int8_t *, u_int16_t); 45enum cryptoerr cast_init(struct keystate *, u_int8_t *, u_int16_t); 46enum cryptoerr aes_init(struct keystate *, u_int8_t *, u_int16_t); 47void des1_encrypt(struct keystate *, u_int8_t *, u_int16_t); 48void des1_decrypt(struct keystate *, u_int8_t *, u_int16_t); 49void des3_encrypt(struct keystate *, u_int8_t *, u_int16_t); 50void des3_decrypt(struct keystate *, u_int8_t *, u_int16_t); 51void blf_encrypt(struct keystate *, u_int8_t *, u_int16_t); 52void blf_decrypt(struct keystate *, u_int8_t *, u_int16_t); 53void cast1_encrypt(struct keystate *, u_int8_t *, u_int16_t); 54void cast1_decrypt(struct keystate *, u_int8_t *, u_int16_t); 55void aes_encrypt(struct keystate *, u_int8_t *, u_int16_t); 56void aes_decrypt(struct keystate *, u_int8_t *, u_int16_t); 57 58struct crypto_xf transforms[] = { 59#ifdef USE_DES 60 { 61 DES_CBC, "Data Encryption Standard (CBC-Mode)", 8, 8, 62 BLOCKSIZE, 0, 63 des1_init, 64 des1_encrypt, des1_decrypt 65 }, 66#endif 67#ifdef USE_TRIPLEDES 68 { 69 TRIPLEDES_CBC, "Triple-DES (CBC-Mode)", 24, 24, 70 BLOCKSIZE, 0, 71 des3_init, 72 des3_encrypt, des3_decrypt 73 }, 74#endif 75#ifdef USE_BLOWFISH 76 { 77 BLOWFISH_CBC, "Blowfish (CBC-Mode)", 12, 56, 78 BLOCKSIZE, 0, 79 blf_init, 80 blf_encrypt, blf_decrypt 81 }, 82#endif 83#ifdef USE_CAST 84 { 85 CAST_CBC, "CAST (CBC-Mode)", 12, 16, 86 BLOCKSIZE, 0, 87 cast_init, 88 cast1_encrypt, cast1_decrypt 89 }, 90#endif 91#ifdef USE_AES 92 { 93 AES_CBC, "AES (CBC-Mode)", 16, 32, 94 AES_BLOCK_SIZE, 0, 95 aes_init, 96 aes_encrypt, aes_decrypt 97 }, 98#endif 99}; 100 101/* Hmm, the function prototypes for des are really dumb */ 102#ifdef __OpenBSD__ 103#define DC (des_cblock *) 104#else 105#define DC (void *) 106#endif 107 108enum cryptoerr 109des1_init(struct keystate *ks, u_int8_t *key, u_int16_t len) 110{ 111 /* des_set_key returns -1 for parity problems, and -2 for weak keys */ 112 des_set_odd_parity(DC key); 113 switch (des_set_key(DC key, ks->ks_des[0])) { 114 case -2: 115 return EWEAKKEY; 116 default: 117 return EOKAY; 118 } 119} 120 121void 122des1_encrypt(struct keystate *ks, u_int8_t *d, u_int16_t len) 123{ 124 des_cbc_encrypt(DC d, DC d, len, ks->ks_des[0], DC ks->riv, 125 DES_ENCRYPT); 126} 127 128void 129des1_decrypt(struct keystate *ks, u_int8_t *d, u_int16_t len) 130{ 131 des_cbc_encrypt(DC d, DC d, len, ks->ks_des[0], DC ks->riv, 132 DES_DECRYPT); 133} 134 135#ifdef USE_TRIPLEDES 136enum cryptoerr 137des3_init(struct keystate *ks, u_int8_t *key, u_int16_t len) 138{ 139 des_set_odd_parity(DC key); 140 des_set_odd_parity(DC(key + 8)); 141 des_set_odd_parity(DC(key + 16)); 142 143 /* As of the draft Tripe-DES does not check for weak keys */ 144 des_set_key(DC key, ks->ks_des[0]); 145 des_set_key(DC(key + 8), ks->ks_des[1]); 146 des_set_key(DC(key + 16), ks->ks_des[2]); 147 148 return EOKAY; 149} 150 151void 152des3_encrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 153{ 154 u_int8_t iv[MAXBLK]; 155 156 memcpy(iv, ks->riv, ks->xf->blocksize); 157 des_ede3_cbc_encrypt(DC data, DC data, len, ks->ks_des[0], 158 ks->ks_des[1], ks->ks_des[2], DC iv, DES_ENCRYPT); 159} 160 161void 162des3_decrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 163{ 164 u_int8_t iv[MAXBLK]; 165 166 memcpy(iv, ks->riv, ks->xf->blocksize); 167 des_ede3_cbc_encrypt(DC data, DC data, len, ks->ks_des[0], 168 ks->ks_des[1], ks->ks_des[2], DC iv, DES_DECRYPT); 169} 170#undef DC 171#endif /* USE_TRIPLEDES */ 172 173#ifdef USE_BLOWFISH 174enum cryptoerr 175blf_init(struct keystate *ks, u_int8_t *key, u_int16_t len) 176{ 177 blf_key(&ks->ks_blf, key, len); 178 179 return EOKAY; 180} 181 182void 183blf_encrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 184{ 185 u_int16_t i, blocksize = ks->xf->blocksize; 186 u_int8_t *iv = ks->liv; 187 u_int32_t xl, xr; 188 189 memcpy(iv, ks->riv, blocksize); 190 191 for (i = 0; i < len; data += blocksize, i += blocksize) { 192 XOR64(data, iv); 193 xl = GET_32BIT_BIG(data); 194 xr = GET_32BIT_BIG(data + 4); 195 Blowfish_encipher(&ks->ks_blf, &xl, &xr); 196 SET_32BIT_BIG(data, xl); 197 SET_32BIT_BIG(data + 4, xr); 198 SET64(iv, data); 199 } 200} 201 202void 203blf_decrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 204{ 205 u_int16_t i, blocksize = ks->xf->blocksize; 206 u_int32_t xl, xr; 207 208 data += len - blocksize; 209 for (i = len - blocksize; i >= blocksize; data -= blocksize, 210 i -= blocksize) { 211 xl = GET_32BIT_BIG(data); 212 xr = GET_32BIT_BIG(data + 4); 213 Blowfish_decipher(&ks->ks_blf, &xl, &xr); 214 SET_32BIT_BIG(data, xl); 215 SET_32BIT_BIG(data + 4, xr); 216 XOR64(data, data - blocksize); 217 218 } 219 xl = GET_32BIT_BIG(data); 220 xr = GET_32BIT_BIG(data + 4); 221 Blowfish_decipher(&ks->ks_blf, &xl, &xr); 222 SET_32BIT_BIG(data, xl); 223 SET_32BIT_BIG(data + 4, xr); 224 XOR64(data, ks->riv); 225} 226#endif /* USE_BLOWFISH */ 227 228#ifdef USE_CAST 229enum cryptoerr 230cast_init(struct keystate *ks, u_int8_t *key, u_int16_t len) 231{ 232 cast_setkey(&ks->ks_cast, key, len); 233 return EOKAY; 234} 235 236void 237cast1_encrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 238{ 239 u_int16_t i, blocksize = ks->xf->blocksize; 240 u_int8_t *iv = ks->liv; 241 242 memcpy(iv, ks->riv, blocksize); 243 244 for (i = 0; i < len; data += blocksize, i += blocksize) { 245 XOR64(data, iv); 246 cast_encrypt(&ks->ks_cast, data, data); 247 SET64(iv, data); 248 } 249} 250 251void 252cast1_decrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 253{ 254 u_int16_t i, blocksize = ks->xf->blocksize; 255 256 data += len - blocksize; 257 for (i = len - blocksize; i >= blocksize; data -= blocksize, 258 i -= blocksize) { 259 cast_decrypt(&ks->ks_cast, data, data); 260 XOR64(data, data - blocksize); 261 } 262 cast_decrypt(&ks->ks_cast, data, data); 263 XOR64(data, ks->riv); 264} 265#endif /* USE_CAST */ 266 267#ifdef USE_AES 268enum cryptoerr 269aes_init(struct keystate *ks, u_int8_t *key, u_int16_t len) 270{ 271 AES_set_encrypt_key(key, len << 3, &ks->ks_aes[0]); 272 AES_set_decrypt_key(key, len << 3, &ks->ks_aes[1]); 273 return EOKAY; 274} 275 276void 277aes_encrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 278{ 279 u_int8_t iv[MAXBLK]; 280 281 memcpy(iv, ks->riv, ks->xf->blocksize); 282 AES_cbc_encrypt(data, data, len, &ks->ks_aes[0], iv, AES_ENCRYPT); 283} 284 285void 286aes_decrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 287{ 288 u_int8_t iv[MAXBLK]; 289 290 memcpy(iv, ks->riv, ks->xf->blocksize); 291 AES_cbc_encrypt(data, data, len, &ks->ks_aes[1], iv, AES_DECRYPT); 292} 293#endif /* USE_AES */ 294 295struct crypto_xf * 296crypto_get(enum transform id) 297{ 298 size_t i; 299 300 for (i = 0; i < sizeof transforms / sizeof transforms[0]; i++) 301 if (id == transforms[i].id) 302 return &transforms[i]; 303 304 return 0; 305} 306 307struct keystate * 308crypto_init(struct crypto_xf *xf, u_int8_t *key, u_int16_t len, 309 enum cryptoerr *err) 310{ 311 struct keystate *ks; 312 313 if (len < xf->keymin || len > xf->keymax) { 314 LOG_DBG((LOG_CRYPTO, 10, "crypto_init: invalid key length %d", 315 len)); 316 *err = EKEYLEN; 317 return 0; 318 } 319 ks = calloc(1, sizeof *ks); 320 if (!ks) { 321 log_error("crypto_init: calloc (1, %lu) failed", 322 (unsigned long)sizeof *ks); 323 *err = ENOCRYPTO; 324 return 0; 325 } 326 ks->xf = xf; 327 328 /* Setup the IV. */ 329 ks->riv = ks->iv; 330 ks->liv = ks->iv2; 331 332 LOG_DBG_BUF((LOG_CRYPTO, 40, "crypto_init: key", key, len)); 333 334 *err = xf->init(ks, key, len); 335 if (*err != EOKAY) { 336 LOG_DBG((LOG_CRYPTO, 30, "crypto_init: weak key found for %s", 337 xf->name)); 338 free(ks); 339 return 0; 340 } 341 return ks; 342} 343 344void 345crypto_update_iv(struct keystate *ks) 346{ 347 u_int8_t *tmp; 348 349 tmp = ks->riv; 350 ks->riv = ks->liv; 351 ks->liv = tmp; 352 353 LOG_DBG_BUF((LOG_CRYPTO, 50, "crypto_update_iv: updated IV", ks->riv, 354 ks->xf->blocksize)); 355} 356 357void 358crypto_init_iv(struct keystate *ks, u_int8_t *buf, size_t len) 359{ 360 memcpy(ks->riv, buf, len); 361 362 LOG_DBG_BUF((LOG_CRYPTO, 50, "crypto_init_iv: initialized IV", ks->riv, 363 len)); 364} 365 366void 367crypto_encrypt(struct keystate *ks, u_int8_t *buf, u_int16_t len) 368{ 369 LOG_DBG_BUF((LOG_CRYPTO, 10, "crypto_encrypt: before encryption", buf, 370 len)); 371 ks->xf->encrypt(ks, buf, len); 372 memcpy(ks->liv, buf + len - ks->xf->blocksize, ks->xf->blocksize); 373 LOG_DBG_BUF((LOG_CRYPTO, 30, "crypto_encrypt: after encryption", buf, 374 len)); 375} 376 377void 378crypto_decrypt(struct keystate *ks, u_int8_t *buf, u_int16_t len) 379{ 380 LOG_DBG_BUF((LOG_CRYPTO, 10, "crypto_decrypt: before decryption", buf, 381 len)); 382 /* 383 * XXX There is controversy about the correctness of updating the IV 384 * like this. 385 */ 386 memcpy(ks->liv, buf + len - ks->xf->blocksize, ks->xf->blocksize); 387 ks->xf->decrypt(ks, buf, len); 388 LOG_DBG_BUF((LOG_CRYPTO, 30, "crypto_decrypt: after decryption", buf, 389 len)); 390} 391 392/* Make a copy of the keystate pointed to by OKS. */ 393struct keystate * 394crypto_clone_keystate(struct keystate *oks) 395{ 396 struct keystate *ks; 397 398 ks = malloc(sizeof *ks); 399 if (!ks) { 400 log_error("crypto_clone_keystate: malloc (%lu) failed", 401 (unsigned long)sizeof *ks); 402 return 0; 403 } 404 memcpy(ks, oks, sizeof *ks); 405 if (oks->riv == oks->iv) { 406 ks->riv = ks->iv; 407 ks->liv = ks->iv2; 408 } else { 409 ks->riv = ks->iv2; 410 ks->liv = ks->iv; 411 } 412 return ks; 413} 414