crypto.c revision 1.20
1/* $OpenBSD: crypto.c,v 1.20 2004/04/15 18:39:25 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, BLOCKSIZE, 0, 62 des1_init, 63 des1_encrypt, des1_decrypt 64 }, 65#endif 66#ifdef USE_TRIPLEDES 67 { 68 TRIPLEDES_CBC, "Triple-DES (CBC-Mode)", 24, 24, BLOCKSIZE, 0, 69 des3_init, 70 des3_encrypt, des3_decrypt 71 }, 72#endif 73#ifdef USE_BLOWFISH 74 { 75 BLOWFISH_CBC, "Blowfish (CBC-Mode)", 12, 56, BLOCKSIZE, 0, 76 blf_init, 77 blf_encrypt, blf_decrypt 78 }, 79#endif 80#ifdef USE_CAST 81 { 82 CAST_CBC, "CAST (CBC-Mode)", 12, 16, BLOCKSIZE, 0, 83 cast_init, 84 cast1_encrypt, cast1_decrypt 85 }, 86#endif 87#ifdef USE_AES 88 { 89 AES_CBC, "AES (CBC-Mode)", 16, 32, AES_BLOCK_SIZE, 0, 90 aes_init, 91 aes_encrypt, aes_decrypt 92 }, 93#endif 94}; 95 96/* Hmm, the function prototypes for des are really dumb */ 97#ifdef __OpenBSD__ 98#define DC (des_cblock *) 99#else 100#define DC (void *) 101#endif 102 103enum cryptoerr 104des1_init(struct keystate * ks, u_int8_t * key, u_int16_t len) 105{ 106 /* des_set_key returns -1 for parity problems, and -2 for weak keys */ 107 des_set_odd_parity(DC key); 108 switch (des_set_key(DC key, ks->ks_des[0])) { 109 case -2: 110 return EWEAKKEY; 111 default: 112 return EOKAY; 113 } 114} 115 116void 117des1_encrypt(struct keystate * ks, u_int8_t * d, u_int16_t len) 118{ 119 des_cbc_encrypt(DC d, DC d, len, ks->ks_des[0], DC ks->riv, 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, DES_DECRYPT); 126} 127 128#ifdef USE_TRIPLEDES 129enum cryptoerr 130des3_init(struct keystate * ks, u_int8_t * key, u_int16_t len) 131{ 132 des_set_odd_parity(DC key); 133 des_set_odd_parity(DC(key + 8)); 134 des_set_odd_parity(DC(key + 16)); 135 136 /* As of the draft Tripe-DES does not check for weak keys */ 137 des_set_key(DC key, ks->ks_des[0]); 138 des_set_key(DC(key + 8), ks->ks_des[1]); 139 des_set_key(DC(key + 16), ks->ks_des[2]); 140 141 return EOKAY; 142} 143 144void 145des3_encrypt(struct keystate * ks, u_int8_t * data, u_int16_t len) 146{ 147 u_int8_t iv[MAXBLK]; 148 149 memcpy(iv, ks->riv, ks->xf->blocksize); 150 des_ede3_cbc_encrypt(DC data, DC data, len, ks->ks_des[0], ks->ks_des[1], 151 ks->ks_des[2], DC iv, DES_ENCRYPT); 152} 153 154void 155des3_decrypt(struct keystate * ks, u_int8_t * data, u_int16_t len) 156{ 157 u_int8_t iv[MAXBLK]; 158 159 memcpy(iv, ks->riv, ks->xf->blocksize); 160 des_ede3_cbc_encrypt(DC data, DC data, len, ks->ks_des[0], ks->ks_des[1], 161 ks->ks_des[2], DC iv, DES_DECRYPT); 162} 163#undef DC 164#endif /* USE_TRIPLEDES */ 165 166#ifdef USE_BLOWFISH 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, i -= blocksize) { 203 xl = GET_32BIT_BIG(data); 204 xr = GET_32BIT_BIG(data + 4); 205 Blowfish_decipher(&ks->ks_blf, &xl, &xr); 206 SET_32BIT_BIG(data, xl); 207 SET_32BIT_BIG(data + 4, xr); 208 XOR64(data, data - blocksize); 209 210 } 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, ks->riv); 217} 218#endif /* USE_BLOWFISH */ 219 220#ifdef USE_CAST 221enum cryptoerr 222cast_init(struct keystate * ks, u_int8_t * key, u_int16_t len) 223{ 224 cast_setkey(&ks->ks_cast, key, len); 225 return EOKAY; 226} 227 228void 229cast1_encrypt(struct keystate * ks, u_int8_t * data, u_int16_t len) 230{ 231 u_int16_t i, blocksize = ks->xf->blocksize; 232 u_int8_t *iv = ks->liv; 233 234 memcpy(iv, ks->riv, blocksize); 235 236 for (i = 0; i < len; data += blocksize, i += blocksize) { 237 XOR64(data, iv); 238 cast_encrypt(&ks->ks_cast, data, data); 239 SET64(iv, data); 240 } 241} 242 243void 244cast1_decrypt(struct keystate * ks, u_int8_t * data, u_int16_t len) 245{ 246 u_int16_t i, blocksize = ks->xf->blocksize; 247 248 data += len - blocksize; 249 for (i = len - blocksize; i >= blocksize; data -= blocksize, 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#endif /* USE_CAST */ 257 258#ifdef USE_AES 259enum cryptoerr 260aes_init(struct keystate * ks, u_int8_t * key, u_int16_t len) 261{ 262 AES_set_encrypt_key(key, len << 3, &ks->ks_aes[0]); 263 AES_set_decrypt_key(key, len << 3, &ks->ks_aes[1]); 264 return EOKAY; 265} 266 267void 268aes_encrypt(struct keystate * ks, u_int8_t * data, u_int16_t len) 269{ 270 u_int8_t iv[MAXBLK]; 271 272 memcpy(iv, ks->riv, ks->xf->blocksize); 273 AES_cbc_encrypt(data, data, len, &ks->ks_aes[0], iv, AES_ENCRYPT); 274} 275 276void 277aes_decrypt(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[1], iv, AES_DECRYPT); 283} 284#endif /* USE_AES */ 285 286struct crypto_xf * 287crypto_get(enum transform id) 288{ 289 size_t i; 290 291 for (i = 0; i < sizeof transforms / sizeof transforms[0]; i++) 292 if (id == transforms[i].id) 293 return &transforms[i]; 294 295 return 0; 296} 297 298struct keystate * 299crypto_init(struct crypto_xf * xf, u_int8_t * key, u_int16_t len, 300 enum cryptoerr * err) 301{ 302 struct keystate *ks; 303 304 if (len < xf->keymin || len > xf->keymax) { 305 LOG_DBG((LOG_CRYPTO, 10, "crypto_init: invalid key length %d", len)); 306 *err = EKEYLEN; 307 return 0; 308 } 309 ks = calloc(1, sizeof *ks); 310 if (!ks) { 311 log_error("crypto_init: calloc (1, %lu) failed", 312 (unsigned long) sizeof *ks); 313 *err = ENOCRYPTO; 314 return 0; 315 } 316 ks->xf = xf; 317 318 /* Setup the IV. */ 319 ks->riv = ks->iv; 320 ks->liv = ks->iv2; 321 322 LOG_DBG_BUF((LOG_CRYPTO, 40, "crypto_init: key", key, len)); 323 324 *err = xf->init(ks, key, len); 325 if (*err != EOKAY) { 326 LOG_DBG((LOG_CRYPTO, 30, "crypto_init: weak key found for %s", 327 xf->name)); 328 free(ks); 329 return 0; 330 } 331 return ks; 332} 333 334void 335crypto_update_iv(struct keystate * ks) 336{ 337 u_int8_t *tmp; 338 339 tmp = ks->riv; 340 ks->riv = ks->liv; 341 ks->liv = tmp; 342 343 LOG_DBG_BUF((LOG_CRYPTO, 50, "crypto_update_iv: updated IV", ks->riv, 344 ks->xf->blocksize)); 345} 346 347void 348crypto_init_iv(struct keystate * ks, u_int8_t * buf, size_t len) 349{ 350 memcpy(ks->riv, buf, len); 351 352 LOG_DBG_BUF((LOG_CRYPTO, 50, "crypto_init_iv: initialized IV", ks->riv, 353 len)); 354} 355 356void 357crypto_encrypt(struct keystate * ks, u_int8_t * buf, u_int16_t len) 358{ 359 LOG_DBG_BUF((LOG_CRYPTO, 10, "crypto_encrypt: before encryption", buf, 360 len)); 361 ks->xf->encrypt(ks, buf, len); 362 memcpy(ks->liv, buf + len - ks->xf->blocksize, ks->xf->blocksize); 363 LOG_DBG_BUF((LOG_CRYPTO, 30, "crypto_encrypt: after encryption", buf, 364 len)); 365} 366 367void 368crypto_decrypt(struct keystate * ks, u_int8_t * buf, u_int16_t len) 369{ 370 LOG_DBG_BUF((LOG_CRYPTO, 10, "crypto_decrypt: before decryption", buf, 371 len)); 372 /* 373 * XXX There is controversy about the correctness of updating the IV 374 * like this. 375 */ 376 memcpy(ks->liv, buf + len - ks->xf->blocksize, ks->xf->blocksize); 377 ks->xf->decrypt(ks, buf, len); 378 LOG_DBG_BUF((LOG_CRYPTO, 30, "crypto_decrypt: after decryption", buf, 379 len)); 380} 381 382/* Make a copy of the keystate pointed to by OKS. */ 383struct keystate * 384crypto_clone_keystate(struct keystate * oks) 385{ 386 struct keystate *ks; 387 388 ks = malloc(sizeof *ks); 389 if (!ks) { 390 log_error("crypto_clone_keystate: malloc (%lu) failed", 391 (unsigned long) sizeof *ks); 392 return 0; 393 } 394 memcpy(ks, oks, sizeof *ks); 395 if (oks->riv == oks->iv) { 396 ks->riv = ks->iv; 397 ks->liv = ks->iv2; 398 } else { 399 ks->riv = ks->iv2; 400 ks->liv = ks->iv; 401 } 402 return ks; 403} 404