crypto.c revision 1.32
1/* $OpenBSD: crypto.c,v 1.32 2013/03/21 04:30:14 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/types.h> 34#include <stdlib.h> 35#include <string.h> 36 37#include "crypto.h" 38#include "log.h" 39 40enum cryptoerr des1_init(struct keystate *, u_int8_t *, u_int16_t); 41enum cryptoerr des3_init(struct keystate *, u_int8_t *, u_int16_t); 42enum cryptoerr blf_init(struct keystate *, u_int8_t *, u_int16_t); 43enum cryptoerr cast_init(struct keystate *, u_int8_t *, u_int16_t); 44enum cryptoerr aes_init(struct keystate *, u_int8_t *, u_int16_t); 45void des1_encrypt(struct keystate *, u_int8_t *, u_int16_t); 46void des1_decrypt(struct keystate *, u_int8_t *, u_int16_t); 47void des3_encrypt(struct keystate *, u_int8_t *, u_int16_t); 48void des3_decrypt(struct keystate *, u_int8_t *, u_int16_t); 49void blf_encrypt(struct keystate *, u_int8_t *, u_int16_t); 50void blf_decrypt(struct keystate *, u_int8_t *, u_int16_t); 51void cast1_encrypt(struct keystate *, u_int8_t *, u_int16_t); 52void cast1_decrypt(struct keystate *, u_int8_t *, u_int16_t); 53void aes_encrypt(struct keystate *, u_int8_t *, u_int16_t); 54void aes_decrypt(struct keystate *, u_int8_t *, u_int16_t); 55 56struct crypto_xf transforms[] = { 57 { 58 DES_CBC, "Data Encryption Standard (CBC-Mode)", 8, 8, 59 BLOCKSIZE, 0, 60 des1_init, 61 des1_encrypt, des1_decrypt 62 }, 63 { 64 TRIPLEDES_CBC, "Triple-DES (CBC-Mode)", 24, 24, 65 BLOCKSIZE, 0, 66 des3_init, 67 des3_encrypt, des3_decrypt 68 }, 69 { 70 BLOWFISH_CBC, "Blowfish (CBC-Mode)", 12, 56, 71 BLOCKSIZE, 0, 72 blf_init, 73 blf_encrypt, blf_decrypt 74 }, 75 { 76 CAST_CBC, "CAST (CBC-Mode)", 12, 16, 77 BLOCKSIZE, 0, 78 cast_init, 79 cast1_encrypt, cast1_decrypt 80 }, 81 { 82 AES_CBC, "AES (CBC-Mode)", 16, 32, 83 AES_BLOCK_SIZE, 0, 84 aes_init, 85 aes_encrypt, aes_decrypt 86 }, 87}; 88 89enum cryptoerr 90des1_init(struct keystate *ks, u_int8_t *key, u_int16_t len) 91{ 92 /* DES_set_key returns -1 for parity problems, and -2 for weak keys */ 93 DES_set_odd_parity((void *)key); 94 switch (DES_set_key((void *)key, &ks->ks_des[0])) { 95 case -2: 96 return EWEAKKEY; 97 default: 98 return EOKAY; 99 } 100} 101 102void 103des1_encrypt(struct keystate *ks, u_int8_t *d, u_int16_t len) 104{ 105 DES_cbc_encrypt((void *)d, (void *)d, len, &ks->ks_des[0], (void *)ks->riv, 106 DES_ENCRYPT); 107} 108 109void 110des1_decrypt(struct keystate *ks, u_int8_t *d, u_int16_t len) 111{ 112 DES_cbc_encrypt((void *)d, (void *)d, len, &ks->ks_des[0], (void *)ks->riv, 113 DES_DECRYPT); 114} 115 116enum cryptoerr 117des3_init(struct keystate *ks, u_int8_t *key, u_int16_t len) 118{ 119 DES_set_odd_parity((void *)key); 120 DES_set_odd_parity((void *)(key + 8)); 121 DES_set_odd_parity((void *)(key + 16)); 122 123 /* As of the draft Tripe-DES does not check for weak keys */ 124 DES_set_key((void *)key, &ks->ks_des[0]); 125 DES_set_key((void *)(key + 8), &ks->ks_des[1]); 126 DES_set_key((void *)(key + 16), &ks->ks_des[2]); 127 128 return EOKAY; 129} 130 131void 132des3_encrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 133{ 134 u_int8_t iv[MAXBLK]; 135 136 memcpy(iv, ks->riv, ks->xf->blocksize); 137 DES_ede3_cbc_encrypt((void *)data, (void *)data, len, &ks->ks_des[0], 138 &ks->ks_des[1], &ks->ks_des[2], (void *)iv, DES_ENCRYPT); 139} 140 141void 142des3_decrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 143{ 144 u_int8_t iv[MAXBLK]; 145 146 memcpy(iv, ks->riv, ks->xf->blocksize); 147 DES_ede3_cbc_encrypt((void *)data, (void *)data, len, &ks->ks_des[0], 148 &ks->ks_des[1], &ks->ks_des[2], (void *)iv, DES_DECRYPT); 149} 150 151enum cryptoerr 152blf_init(struct keystate *ks, u_int8_t *key, u_int16_t len) 153{ 154 blf_key(&ks->ks_blf, key, len); 155 156 return EOKAY; 157} 158 159void 160blf_encrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 161{ 162 u_int16_t i, blocksize = ks->xf->blocksize; 163 u_int8_t *iv = ks->liv; 164 u_int32_t xl, xr; 165 166 memcpy(iv, ks->riv, blocksize); 167 168 for (i = 0; i < len; data += blocksize, i += blocksize) { 169 XOR64(data, iv); 170 xl = GET_32BIT_BIG(data); 171 xr = GET_32BIT_BIG(data + 4); 172 Blowfish_encipher(&ks->ks_blf, &xl, &xr); 173 SET_32BIT_BIG(data, xl); 174 SET_32BIT_BIG(data + 4, xr); 175 SET64(iv, data); 176 } 177} 178 179void 180blf_decrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 181{ 182 u_int16_t i, blocksize = ks->xf->blocksize; 183 u_int32_t xl, xr; 184 185 data += len - blocksize; 186 for (i = len - blocksize; i >= blocksize; data -= blocksize, 187 i -= blocksize) { 188 xl = GET_32BIT_BIG(data); 189 xr = GET_32BIT_BIG(data + 4); 190 Blowfish_decipher(&ks->ks_blf, &xl, &xr); 191 SET_32BIT_BIG(data, xl); 192 SET_32BIT_BIG(data + 4, xr); 193 XOR64(data, data - blocksize); 194 195 } 196 xl = GET_32BIT_BIG(data); 197 xr = GET_32BIT_BIG(data + 4); 198 Blowfish_decipher(&ks->ks_blf, &xl, &xr); 199 SET_32BIT_BIG(data, xl); 200 SET_32BIT_BIG(data + 4, xr); 201 XOR64(data, ks->riv); 202} 203 204enum cryptoerr 205cast_init(struct keystate *ks, u_int8_t *key, u_int16_t len) 206{ 207 CAST_set_key(&ks->ks_cast, len, key); 208 return EOKAY; 209} 210 211void 212cast1_encrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 213{ 214 memcpy(ks->liv, ks->riv, ks->xf->blocksize); 215 CAST_cbc_encrypt(data, data, len, &ks->ks_cast, ks->liv, 1); 216} 217 218void 219cast1_decrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 220{ 221 CAST_cbc_encrypt(data, data, len, &ks->ks_cast, ks->riv, 0); 222} 223 224enum cryptoerr 225aes_init(struct keystate *ks, u_int8_t *key, u_int16_t len) 226{ 227 AES_set_encrypt_key(key, len << 3, &ks->ks_aes[0]); 228 AES_set_decrypt_key(key, len << 3, &ks->ks_aes[1]); 229 return EOKAY; 230} 231 232void 233aes_encrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 234{ 235 u_int8_t iv[MAXBLK]; 236 237 memcpy(iv, ks->riv, ks->xf->blocksize); 238 AES_cbc_encrypt(data, data, len, &ks->ks_aes[0], iv, AES_ENCRYPT); 239} 240 241void 242aes_decrypt(struct keystate *ks, u_int8_t *data, u_int16_t len) 243{ 244 u_int8_t iv[MAXBLK]; 245 246 memcpy(iv, ks->riv, ks->xf->blocksize); 247 AES_cbc_encrypt(data, data, len, &ks->ks_aes[1], iv, AES_DECRYPT); 248} 249 250struct crypto_xf * 251crypto_get(enum transform id) 252{ 253 size_t i; 254 255 for (i = 0; i < sizeof transforms / sizeof transforms[0]; i++) 256 if (id == transforms[i].id) 257 return &transforms[i]; 258 259 return 0; 260} 261 262struct keystate * 263crypto_init(struct crypto_xf *xf, u_int8_t *key, u_int16_t len, 264 enum cryptoerr *err) 265{ 266 struct keystate *ks; 267 268 if (len < xf->keymin || len > xf->keymax) { 269 LOG_DBG((LOG_CRYPTO, 10, "crypto_init: invalid key length %d", 270 len)); 271 *err = EKEYLEN; 272 return 0; 273 } 274 ks = calloc(1, sizeof *ks); 275 if (!ks) { 276 log_error("crypto_init: calloc (1, %lu) failed", 277 (unsigned long)sizeof *ks); 278 *err = ENOCRYPTO; 279 return 0; 280 } 281 ks->xf = xf; 282 283 /* Setup the IV. */ 284 ks->riv = ks->iv; 285 ks->liv = ks->iv2; 286 287 LOG_DBG_BUF((LOG_CRYPTO, 40, "crypto_init: key", key, len)); 288 289 *err = xf->init(ks, key, len); 290 if (*err != EOKAY) { 291 LOG_DBG((LOG_CRYPTO, 30, "crypto_init: weak key found for %s", 292 xf->name)); 293 free(ks); 294 return 0; 295 } 296 return ks; 297} 298 299void 300crypto_update_iv(struct keystate *ks) 301{ 302 u_int8_t *tmp; 303 304 tmp = ks->riv; 305 ks->riv = ks->liv; 306 ks->liv = tmp; 307 308 LOG_DBG_BUF((LOG_CRYPTO, 50, "crypto_update_iv: updated IV", ks->riv, 309 ks->xf->blocksize)); 310} 311 312void 313crypto_init_iv(struct keystate *ks, u_int8_t *buf, size_t len) 314{ 315 memcpy(ks->riv, buf, len); 316 317 LOG_DBG_BUF((LOG_CRYPTO, 50, "crypto_init_iv: initialized IV", ks->riv, 318 len)); 319} 320 321void 322crypto_encrypt(struct keystate *ks, u_int8_t *buf, u_int16_t len) 323{ 324 LOG_DBG_BUF((LOG_CRYPTO, 70, "crypto_encrypt: before encryption", buf, 325 len)); 326 ks->xf->encrypt(ks, buf, len); 327 memcpy(ks->liv, buf + len - ks->xf->blocksize, ks->xf->blocksize); 328 LOG_DBG_BUF((LOG_CRYPTO, 70, "crypto_encrypt: after encryption", buf, 329 len)); 330} 331 332void 333crypto_decrypt(struct keystate *ks, u_int8_t *buf, u_int16_t len) 334{ 335 LOG_DBG_BUF((LOG_CRYPTO, 70, "crypto_decrypt: before decryption", buf, 336 len)); 337 /* 338 * XXX There is controversy about the correctness of updating the IV 339 * like this. 340 */ 341 memcpy(ks->liv, buf + len - ks->xf->blocksize, ks->xf->blocksize); 342 ks->xf->decrypt(ks, buf, len); 343 LOG_DBG_BUF((LOG_CRYPTO, 70, "crypto_decrypt: after decryption", buf, 344 len)); 345} 346 347/* Make a copy of the keystate pointed to by OKS. */ 348struct keystate * 349crypto_clone_keystate(struct keystate *oks) 350{ 351 struct keystate *ks; 352 353 ks = malloc(sizeof *ks); 354 if (!ks) { 355 log_error("crypto_clone_keystate: malloc (%lu) failed", 356 (unsigned long)sizeof *ks); 357 return 0; 358 } 359 memcpy(ks, oks, sizeof *ks); 360 if (oks->riv == oks->iv) { 361 ks->riv = ks->iv; 362 ks->liv = ks->iv2; 363 } else { 364 ks->riv = ks->iv2; 365 ks->liv = ks->iv; 366 } 367 return ks; 368} 369