crypto.c revision 1.25
1/* $OpenBSD: crypto.c,v 1.25 2005/04/08 16:06:25 deraadt 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 { 76 BLOWFISH_CBC, "Blowfish (CBC-Mode)", 12, 56, 77 BLOCKSIZE, 0, 78 blf_init, 79 blf_encrypt, blf_decrypt 80 }, 81 { 82 CAST_CBC, "CAST (CBC-Mode)", 12, 16, 83 BLOCKSIZE, 0, 84 cast_init, 85 cast1_encrypt, cast1_decrypt 86 }, 87 { 88 AES_CBC, "AES (CBC-Mode)", 16, 32, 89 AES_BLOCK_SIZE, 0, 90 aes_init, 91 aes_encrypt, aes_decrypt 92 }, 93}; 94 95/* Hmm, the function prototypes for des are really dumb */ 96#ifdef __OpenBSD__ 97#define DC (des_cblock *) 98#else 99#define DC (void *) 100#endif 101 102enum cryptoerr 103des1_init(struct keystate *ks, u_int8_t *key, u_int16_t len) 104{ 105 /* des_set_key returns -1 for parity problems, and -2 for weak keys */ 106 des_set_odd_parity(DC key); 107 switch (des_set_key(DC key, ks->ks_des[0])) { 108 case -2: 109 return EWEAKKEY; 110 default: 111 return EOKAY; 112 } 113} 114 115void 116des1_encrypt(struct keystate *ks, u_int8_t *d, u_int16_t len) 117{ 118 des_cbc_encrypt(DC d, DC d, len, ks->ks_des[0], DC ks->riv, 119 DES_ENCRYPT); 120} 121 122void 123des1_decrypt(struct keystate *ks, u_int8_t *d, u_int16_t len) 124{ 125 des_cbc_encrypt(DC d, DC d, len, ks->ks_des[0], DC ks->riv, 126 DES_DECRYPT); 127} 128 129#ifdef USE_TRIPLEDES 130enum cryptoerr 131des3_init(struct keystate *ks, u_int8_t *key, u_int16_t len) 132{ 133 des_set_odd_parity(DC key); 134 des_set_odd_parity(DC(key + 8)); 135 des_set_odd_parity(DC(key + 16)); 136 137 /* As of the draft Tripe-DES does not check for weak keys */ 138 des_set_key(DC key, ks->ks_des[0]); 139 des_set_key(DC(key + 8), ks->ks_des[1]); 140 des_set_key(DC(key + 16), ks->ks_des[2]); 141 142 return EOKAY; 143} 144 145void 146des3_encrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 147{ 148 u_int8_t iv[MAXBLK]; 149 150 memcpy(iv, ks->riv, ks->xf->blocksize); 151 des_ede3_cbc_encrypt(DC data, DC data, len, ks->ks_des[0], 152 ks->ks_des[1], ks->ks_des[2], DC iv, DES_ENCRYPT); 153} 154 155void 156des3_decrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 157{ 158 u_int8_t iv[MAXBLK]; 159 160 memcpy(iv, ks->riv, ks->xf->blocksize); 161 des_ede3_cbc_encrypt(DC data, DC data, len, ks->ks_des[0], 162 ks->ks_des[1], ks->ks_des[2], DC iv, DES_DECRYPT); 163} 164#undef DC 165#endif /* USE_TRIPLEDES */ 166 167enum cryptoerr 168blf_init(struct keystate *ks, u_int8_t *key, u_int16_t len) 169{ 170 blf_key(&ks->ks_blf, key, len); 171 172 return EOKAY; 173} 174 175void 176blf_encrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 177{ 178 u_int16_t i, blocksize = ks->xf->blocksize; 179 u_int8_t *iv = ks->liv; 180 u_int32_t xl, xr; 181 182 memcpy(iv, ks->riv, blocksize); 183 184 for (i = 0; i < len; data += blocksize, i += blocksize) { 185 XOR64(data, iv); 186 xl = GET_32BIT_BIG(data); 187 xr = GET_32BIT_BIG(data + 4); 188 Blowfish_encipher(&ks->ks_blf, &xl, &xr); 189 SET_32BIT_BIG(data, xl); 190 SET_32BIT_BIG(data + 4, xr); 191 SET64(iv, data); 192 } 193} 194 195void 196blf_decrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 197{ 198 u_int16_t i, blocksize = ks->xf->blocksize; 199 u_int32_t xl, xr; 200 201 data += len - blocksize; 202 for (i = len - blocksize; i >= blocksize; data -= blocksize, 203 i -= blocksize) { 204 xl = GET_32BIT_BIG(data); 205 xr = GET_32BIT_BIG(data + 4); 206 Blowfish_decipher(&ks->ks_blf, &xl, &xr); 207 SET_32BIT_BIG(data, xl); 208 SET_32BIT_BIG(data + 4, xr); 209 XOR64(data, data - blocksize); 210 211 } 212 xl = GET_32BIT_BIG(data); 213 xr = GET_32BIT_BIG(data + 4); 214 Blowfish_decipher(&ks->ks_blf, &xl, &xr); 215 SET_32BIT_BIG(data, xl); 216 SET_32BIT_BIG(data + 4, xr); 217 XOR64(data, ks->riv); 218} 219 220enum cryptoerr 221cast_init(struct keystate *ks, u_int8_t *key, u_int16_t len) 222{ 223 cast_setkey(&ks->ks_cast, key, len); 224 return EOKAY; 225} 226 227void 228cast1_encrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 229{ 230 u_int16_t i, blocksize = ks->xf->blocksize; 231 u_int8_t *iv = ks->liv; 232 233 memcpy(iv, ks->riv, blocksize); 234 235 for (i = 0; i < len; data += blocksize, i += blocksize) { 236 XOR64(data, iv); 237 cast_encrypt(&ks->ks_cast, data, data); 238 SET64(iv, data); 239 } 240} 241 242void 243cast1_decrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 244{ 245 u_int16_t i, blocksize = ks->xf->blocksize; 246 247 data += len - blocksize; 248 for (i = len - blocksize; i >= blocksize; data -= blocksize, 249 i -= blocksize) { 250 cast_decrypt(&ks->ks_cast, data, data); 251 XOR64(data, data - blocksize); 252 } 253 cast_decrypt(&ks->ks_cast, data, data); 254 XOR64(data, ks->riv); 255} 256 257enum cryptoerr 258aes_init(struct keystate *ks, u_int8_t *key, u_int16_t len) 259{ 260 AES_set_encrypt_key(key, len << 3, &ks->ks_aes[0]); 261 AES_set_decrypt_key(key, len << 3, &ks->ks_aes[1]); 262 return EOKAY; 263} 264 265void 266aes_encrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 267{ 268 u_int8_t iv[MAXBLK]; 269 270 memcpy(iv, ks->riv, ks->xf->blocksize); 271 AES_cbc_encrypt(data, data, len, &ks->ks_aes[0], iv, AES_ENCRYPT); 272} 273 274void 275aes_decrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 276{ 277 u_int8_t iv[MAXBLK]; 278 279 memcpy(iv, ks->riv, ks->xf->blocksize); 280 AES_cbc_encrypt(data, data, len, &ks->ks_aes[1], iv, AES_DECRYPT); 281} 282 283struct crypto_xf * 284crypto_get(enum transform id) 285{ 286 size_t i; 287 288 for (i = 0; i < sizeof transforms / sizeof transforms[0]; i++) 289 if (id == transforms[i].id) 290 return &transforms[i]; 291 292 return 0; 293} 294 295struct keystate * 296crypto_init(struct crypto_xf *xf, u_int8_t *key, u_int16_t len, 297 enum cryptoerr *err) 298{ 299 struct keystate *ks; 300 301 if (len < xf->keymin || len > xf->keymax) { 302 LOG_DBG((LOG_CRYPTO, 10, "crypto_init: invalid key length %d", 303 len)); 304 *err = EKEYLEN; 305 return 0; 306 } 307 ks = calloc(1, sizeof *ks); 308 if (!ks) { 309 log_error("crypto_init: calloc (1, %lu) failed", 310 (unsigned long)sizeof *ks); 311 *err = ENOCRYPTO; 312 return 0; 313 } 314 ks->xf = xf; 315 316 /* Setup the IV. */ 317 ks->riv = ks->iv; 318 ks->liv = ks->iv2; 319 320 LOG_DBG_BUF((LOG_CRYPTO, 40, "crypto_init: key", key, len)); 321 322 *err = xf->init(ks, key, len); 323 if (*err != EOKAY) { 324 LOG_DBG((LOG_CRYPTO, 30, "crypto_init: weak key found for %s", 325 xf->name)); 326 free(ks); 327 return 0; 328 } 329 return ks; 330} 331 332void 333crypto_update_iv(struct keystate *ks) 334{ 335 u_int8_t *tmp; 336 337 tmp = ks->riv; 338 ks->riv = ks->liv; 339 ks->liv = tmp; 340 341 LOG_DBG_BUF((LOG_CRYPTO, 50, "crypto_update_iv: updated IV", ks->riv, 342 ks->xf->blocksize)); 343} 344 345void 346crypto_init_iv(struct keystate *ks, u_int8_t *buf, size_t len) 347{ 348 memcpy(ks->riv, buf, len); 349 350 LOG_DBG_BUF((LOG_CRYPTO, 50, "crypto_init_iv: initialized IV", ks->riv, 351 len)); 352} 353 354void 355crypto_encrypt(struct keystate *ks, u_int8_t *buf, u_int16_t len) 356{ 357 LOG_DBG_BUF((LOG_CRYPTO, 30, "crypto_encrypt: before encryption", buf, 358 len)); 359 ks->xf->encrypt(ks, buf, len); 360 memcpy(ks->liv, buf + len - ks->xf->blocksize, ks->xf->blocksize); 361 LOG_DBG_BUF((LOG_CRYPTO, 30, "crypto_encrypt: after encryption", buf, 362 len)); 363} 364 365void 366crypto_decrypt(struct keystate *ks, u_int8_t *buf, u_int16_t len) 367{ 368 LOG_DBG_BUF((LOG_CRYPTO, 30, "crypto_decrypt: before decryption", buf, 369 len)); 370 /* 371 * XXX There is controversy about the correctness of updating the IV 372 * like this. 373 */ 374 memcpy(ks->liv, buf + len - ks->xf->blocksize, ks->xf->blocksize); 375 ks->xf->decrypt(ks, buf, len); 376 LOG_DBG_BUF((LOG_CRYPTO, 30, "crypto_decrypt: after decryption", buf, 377 len)); 378} 379 380/* Make a copy of the keystate pointed to by OKS. */ 381struct keystate * 382crypto_clone_keystate(struct keystate *oks) 383{ 384 struct keystate *ks; 385 386 ks = malloc(sizeof *ks); 387 if (!ks) { 388 log_error("crypto_clone_keystate: malloc (%lu) failed", 389 (unsigned long)sizeof *ks); 390 return 0; 391 } 392 memcpy(ks, oks, sizeof *ks); 393 if (oks->riv == oks->iv) { 394 ks->riv = ks->iv; 395 ks->liv = ks->iv2; 396 } else { 397 ks->riv = ks->iv2; 398 ks->liv = ks->iv; 399 } 400 return ks; 401} 402