1/* 2 * Copyright (c) 2000 - 2004 Kungliga Tekniska Högskolan 3 * (Royal Institute of Technology, Stockholm, Sweden). 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 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 * 3. Neither the name of the Institute nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34#include "hdb_locl.h" 35#ifndef O_BINARY 36#define O_BINARY 0 37#endif 38 39struct hdb_master_key_data { 40 krb5_keytab_entry keytab; 41 krb5_crypto crypto; 42 struct hdb_master_key_data *next; 43}; 44 45void 46hdb_free_master_key(krb5_context context, hdb_master_key mkey) 47{ 48 struct hdb_master_key_data *ptr; 49 while(mkey) { 50 krb5_kt_free_entry(context, &mkey->keytab); 51 if (mkey->crypto) 52 krb5_crypto_destroy(context, mkey->crypto); 53 ptr = mkey; 54 mkey = mkey->next; 55 free(ptr); 56 } 57} 58 59krb5_error_code 60hdb_process_master_key(krb5_context context, 61 int kvno, krb5_keyblock *key, krb5_enctype etype, 62 hdb_master_key *mkey) 63{ 64 krb5_error_code ret; 65 66 *mkey = calloc(1, sizeof(**mkey)); 67 if(*mkey == NULL) { 68 krb5_set_error_message(context, ENOMEM, "malloc: out of memory"); 69 return ENOMEM; 70 } 71 (*mkey)->keytab.vno = kvno; 72 ret = krb5_parse_name(context, "K/M", &(*mkey)->keytab.principal); 73 if(ret) 74 goto fail; 75 ret = krb5_copy_keyblock_contents(context, key, &(*mkey)->keytab.keyblock); 76 if(ret) 77 goto fail; 78 if(etype != 0) 79 (*mkey)->keytab.keyblock.keytype = etype; 80 (*mkey)->keytab.timestamp = time(NULL); 81 ret = krb5_crypto_init(context, key, etype, &(*mkey)->crypto); 82 if(ret) 83 goto fail; 84 return 0; 85 fail: 86 hdb_free_master_key(context, *mkey); 87 *mkey = NULL; 88 return ret; 89} 90 91krb5_error_code 92hdb_add_master_key(krb5_context context, krb5_keyblock *key, 93 hdb_master_key *inout) 94{ 95 int vno = 0; 96 hdb_master_key p; 97 krb5_error_code ret; 98 99 for(p = *inout; p; p = p->next) 100 vno = max(vno, p->keytab.vno); 101 vno++; 102 ret = hdb_process_master_key(context, vno, key, 0, &p); 103 if(ret) 104 return ret; 105 p->next = *inout; 106 *inout = p; 107 return 0; 108} 109 110static krb5_error_code 111read_master_keytab(krb5_context context, const char *filename, 112 hdb_master_key *mkey) 113{ 114 krb5_error_code ret; 115 krb5_keytab id; 116 krb5_kt_cursor cursor; 117 krb5_keytab_entry entry; 118 hdb_master_key p; 119 120 ret = krb5_kt_resolve(context, filename, &id); 121 if(ret) 122 return ret; 123 124 ret = krb5_kt_start_seq_get(context, id, &cursor); 125 if(ret) 126 goto out; 127 *mkey = NULL; 128 while(krb5_kt_next_entry(context, id, &entry, &cursor) == 0) { 129 p = calloc(1, sizeof(*p)); 130 if(p == NULL) { 131 krb5_kt_end_seq_get(context, id, &cursor); 132 ret = ENOMEM; 133 goto out; 134 } 135 p->keytab = entry; 136 ret = krb5_crypto_init(context, &p->keytab.keyblock, 0, &p->crypto); 137 p->next = *mkey; 138 *mkey = p; 139 } 140 krb5_kt_end_seq_get(context, id, &cursor); 141 out: 142 krb5_kt_close(context, id); 143 return ret; 144} 145 146/* read a MIT master keyfile */ 147static krb5_error_code 148read_master_mit(krb5_context context, const char *filename, 149 hdb_master_key *mkey) 150{ 151 int fd; 152 krb5_error_code ret; 153 krb5_storage *sp; 154 int16_t enctype; 155 krb5_keyblock key; 156 157 fd = open(filename, O_RDONLY | O_BINARY); 158 if(fd < 0) { 159 int save_errno = errno; 160 krb5_set_error_message(context, save_errno, "failed to open %s: %s", 161 filename, strerror(save_errno)); 162 return save_errno; 163 } 164 sp = krb5_storage_from_fd(fd); 165 if(sp == NULL) { 166 close(fd); 167 return errno; 168 } 169 krb5_storage_set_flags(sp, KRB5_STORAGE_HOST_BYTEORDER); 170 /* could possibly use ret_keyblock here, but do it with more 171 checks for now */ 172 { 173 ret = krb5_ret_int16(sp, &enctype); 174 if (ret) 175 goto out; 176 if((htons(enctype) & 0xff00) == 0x3000) { 177 ret = HEIM_ERR_BAD_MKEY; 178 krb5_set_error_message(context, ret, "unknown keytype in %s: " 179 "%#x, expected %#x", 180 filename, htons(enctype), 0x3000); 181 goto out; 182 } 183 key.keytype = enctype; 184 ret = krb5_ret_data(sp, &key.keyvalue); 185 if(ret) 186 goto out; 187 } 188 ret = hdb_process_master_key(context, 0, &key, 0, mkey); 189 krb5_free_keyblock_contents(context, &key); 190 out: 191 krb5_storage_free(sp); 192 close(fd); 193 return ret; 194} 195 196/* read an old master key file */ 197static krb5_error_code 198read_master_encryptionkey(krb5_context context, const char *filename, 199 hdb_master_key *mkey) 200{ 201 int fd; 202 krb5_keyblock key; 203 krb5_error_code ret; 204 unsigned char buf[256]; 205 ssize_t len; 206 size_t ret_len; 207 208 fd = open(filename, O_RDONLY | O_BINARY); 209 if(fd < 0) { 210 int save_errno = errno; 211 krb5_set_error_message(context, save_errno, "failed to open %s: %s", 212 filename, strerror(save_errno)); 213 return save_errno; 214 } 215 216 len = read(fd, buf, sizeof(buf)); 217 close(fd); 218 if(len < 0) { 219 int save_errno = errno; 220 krb5_set_error_message(context, save_errno, "error reading %s: %s", 221 filename, strerror(save_errno)); 222 return save_errno; 223 } 224 225 ret = decode_EncryptionKey(buf, len, &key, &ret_len); 226 memset(buf, 0, sizeof(buf)); 227 if(ret) 228 return ret; 229 230 /* Originally, the keytype was just that, and later it got changed 231 to des-cbc-md5, but we always used des in cfb64 mode. This 232 should cover all cases, but will break if someone has hacked 233 this code to really use des-cbc-md5 -- but then that's not my 234 problem. */ 235 if(key.keytype == KEYTYPE_DES || key.keytype == ETYPE_DES_CBC_MD5) 236 key.keytype = ETYPE_DES_CFB64_NONE; 237 238 ret = hdb_process_master_key(context, 0, &key, 0, mkey); 239 krb5_free_keyblock_contents(context, &key); 240 return ret; 241} 242 243/* read a krb4 /.k style file */ 244static krb5_error_code 245read_master_krb4(krb5_context context, const char *filename, 246 hdb_master_key *mkey) 247{ 248 int fd; 249 krb5_keyblock key; 250 krb5_error_code ret; 251 unsigned char buf[256]; 252 ssize_t len; 253 254 fd = open(filename, O_RDONLY | O_BINARY); 255 if(fd < 0) { 256 int save_errno = errno; 257 krb5_set_error_message(context, save_errno, "failed to open %s: %s", 258 filename, strerror(save_errno)); 259 return save_errno; 260 } 261 262 len = read(fd, buf, sizeof(buf)); 263 close(fd); 264 if(len < 0) { 265 int save_errno = errno; 266 krb5_set_error_message(context, save_errno, "error reading %s: %s", 267 filename, strerror(save_errno)); 268 return save_errno; 269 } 270 if(len != 8) { 271 krb5_set_error_message(context, HEIM_ERR_EOF, 272 "bad contents of %s", filename); 273 return HEIM_ERR_EOF; /* XXX file might be too large */ 274 } 275 276 memset(&key, 0, sizeof(key)); 277 key.keytype = ETYPE_DES_PCBC_NONE; 278 ret = krb5_data_copy(&key.keyvalue, buf, len); 279 memset(buf, 0, sizeof(buf)); 280 if(ret) 281 return ret; 282 283 ret = hdb_process_master_key(context, 0, &key, 0, mkey); 284 krb5_free_keyblock_contents(context, &key); 285 return ret; 286} 287 288krb5_error_code 289hdb_read_master_key(krb5_context context, const char *filename, 290 hdb_master_key *mkey) 291{ 292 FILE *f; 293 unsigned char buf[16]; 294 krb5_error_code ret; 295 296 off_t len; 297 298 *mkey = NULL; 299 300 if(filename == NULL) 301 filename = HDB_DB_DIR "/m-key"; 302 303 f = fopen(filename, "r"); 304 if(f == NULL) { 305 int save_errno = errno; 306 krb5_set_error_message(context, save_errno, "failed to open %s: %s", 307 filename, strerror(save_errno)); 308 return save_errno; 309 } 310 311 if(fread(buf, 1, 2, f) != 2) { 312 fclose(f); 313 krb5_set_error_message(context, HEIM_ERR_EOF, "end of file reading %s", filename); 314 return HEIM_ERR_EOF; 315 } 316 317 fseek(f, 0, SEEK_END); 318 len = ftell(f); 319 320 if(fclose(f) != 0) 321 return errno; 322 323 if(len < 0) 324 return errno; 325 326 if(len == 8) { 327 ret = read_master_krb4(context, filename, mkey); 328 } else if(buf[0] == 0x30 && len <= 127 && buf[1] == len - 2) { 329 ret = read_master_encryptionkey(context, filename, mkey); 330 } else if(buf[0] == 5 && buf[1] >= 1 && buf[1] <= 2) { 331 ret = read_master_keytab(context, filename, mkey); 332 } else { 333 ret = read_master_mit(context, filename, mkey); 334 } 335 return ret; 336} 337 338krb5_error_code 339hdb_write_master_key(krb5_context context, const char *filename, 340 hdb_master_key mkey) 341{ 342 krb5_error_code ret; 343 hdb_master_key p; 344 krb5_keytab kt; 345 346 if(filename == NULL) 347 filename = HDB_DB_DIR "/m-key"; 348 349 ret = krb5_kt_resolve(context, filename, &kt); 350 if(ret) 351 return ret; 352 353 for(p = mkey; p; p = p->next) { 354 ret = krb5_kt_add_entry(context, kt, &p->keytab); 355 } 356 357 krb5_kt_close(context, kt); 358 359 return ret; 360} 361 362hdb_master_key 363_hdb_find_master_key(uint32_t *mkvno, hdb_master_key mkey) 364{ 365 hdb_master_key ret = NULL; 366 while(mkey) { 367 if(ret == NULL && mkey->keytab.vno == 0) 368 ret = mkey; 369 if(mkvno == NULL) { 370 if(ret == NULL || mkey->keytab.vno > ret->keytab.vno) 371 ret = mkey; 372 } else if(mkey->keytab.vno == *mkvno) 373 return mkey; 374 mkey = mkey->next; 375 } 376 return ret; 377} 378 379int 380_hdb_mkey_version(hdb_master_key mkey) 381{ 382 return mkey->keytab.vno; 383} 384 385int 386_hdb_mkey_decrypt(krb5_context context, hdb_master_key key, 387 krb5_key_usage usage, 388 void *ptr, size_t size, krb5_data *res) 389{ 390 return krb5_decrypt(context, key->crypto, usage, 391 ptr, size, res); 392} 393 394int 395_hdb_mkey_encrypt(krb5_context context, hdb_master_key key, 396 krb5_key_usage usage, 397 const void *ptr, size_t size, krb5_data *res) 398{ 399 return krb5_encrypt(context, key->crypto, usage, 400 ptr, size, res); 401} 402 403krb5_error_code 404hdb_unseal_key_mkey(krb5_context context, Key *k, hdb_master_key mkey) 405{ 406 407 krb5_error_code ret; 408 krb5_data res; 409 size_t keysize; 410 411 hdb_master_key key; 412 413 if(k->mkvno == NULL) 414 return 0; 415 416 key = _hdb_find_master_key(k->mkvno, mkey); 417 418 if (key == NULL) 419 return HDB_ERR_NO_MKEY; 420 421 ret = _hdb_mkey_decrypt(context, key, HDB_KU_MKEY, 422 k->key.keyvalue.data, 423 k->key.keyvalue.length, 424 &res); 425 if(ret == KRB5KRB_AP_ERR_BAD_INTEGRITY) { 426 /* try to decrypt with MIT key usage */ 427 ret = _hdb_mkey_decrypt(context, key, 0, 428 k->key.keyvalue.data, 429 k->key.keyvalue.length, 430 &res); 431 } 432 if (ret) 433 return ret; 434 435 /* fixup keylength if the key got padded when encrypting it */ 436 ret = krb5_enctype_keysize(context, k->key.keytype, &keysize); 437 if (ret) { 438 krb5_data_free(&res); 439 return ret; 440 } 441 if (keysize > res.length) { 442 krb5_data_free(&res); 443 return KRB5_BAD_KEYSIZE; 444 } 445 446 memset(k->key.keyvalue.data, 0, k->key.keyvalue.length); 447 free(k->key.keyvalue.data); 448 k->key.keyvalue = res; 449 k->key.keyvalue.length = keysize; 450 free(k->mkvno); 451 k->mkvno = NULL; 452 453 return 0; 454} 455 456krb5_error_code 457hdb_unseal_keys_mkey(krb5_context context, hdb_entry *ent, hdb_master_key mkey) 458{ 459 int i; 460 461 for(i = 0; i < ent->keys.len; i++){ 462 krb5_error_code ret; 463 464 ret = hdb_unseal_key_mkey(context, &ent->keys.val[i], mkey); 465 if (ret) 466 return ret; 467 } 468 return 0; 469} 470 471krb5_error_code 472hdb_unseal_keys(krb5_context context, HDB *db, hdb_entry *ent) 473{ 474 if (db->hdb_master_key_set == 0) 475 return 0; 476 return hdb_unseal_keys_mkey(context, ent, db->hdb_master_key); 477} 478 479krb5_error_code 480hdb_unseal_key(krb5_context context, HDB *db, Key *k) 481{ 482 if (db->hdb_master_key_set == 0) 483 return 0; 484 return hdb_unseal_key_mkey(context, k, db->hdb_master_key); 485} 486 487krb5_error_code 488hdb_seal_key_mkey(krb5_context context, Key *k, hdb_master_key mkey) 489{ 490 krb5_error_code ret; 491 krb5_data res; 492 hdb_master_key key; 493 494 if(k->mkvno != NULL) 495 return 0; 496 497 key = _hdb_find_master_key(k->mkvno, mkey); 498 499 if (key == NULL) 500 return HDB_ERR_NO_MKEY; 501 502 ret = _hdb_mkey_encrypt(context, key, HDB_KU_MKEY, 503 k->key.keyvalue.data, 504 k->key.keyvalue.length, 505 &res); 506 if (ret) 507 return ret; 508 509 memset(k->key.keyvalue.data, 0, k->key.keyvalue.length); 510 free(k->key.keyvalue.data); 511 k->key.keyvalue = res; 512 513 if (k->mkvno == NULL) { 514 k->mkvno = malloc(sizeof(*k->mkvno)); 515 if (k->mkvno == NULL) 516 return ENOMEM; 517 } 518 *k->mkvno = key->keytab.vno; 519 520 return 0; 521} 522 523krb5_error_code 524hdb_seal_keys_mkey(krb5_context context, hdb_entry *ent, hdb_master_key mkey) 525{ 526 int i; 527 for(i = 0; i < ent->keys.len; i++){ 528 krb5_error_code ret; 529 530 ret = hdb_seal_key_mkey(context, &ent->keys.val[i], mkey); 531 if (ret) 532 return ret; 533 } 534 return 0; 535} 536 537krb5_error_code 538hdb_seal_keys(krb5_context context, HDB *db, hdb_entry *ent) 539{ 540 if (db->hdb_master_key_set == 0) 541 return 0; 542 543 return hdb_seal_keys_mkey(context, ent, db->hdb_master_key); 544} 545 546krb5_error_code 547hdb_seal_key(krb5_context context, HDB *db, Key *k) 548{ 549 if (db->hdb_master_key_set == 0) 550 return 0; 551 552 return hdb_seal_key_mkey(context, k, db->hdb_master_key); 553} 554 555krb5_error_code 556hdb_set_master_key (krb5_context context, 557 HDB *db, 558 krb5_keyblock *key) 559{ 560 krb5_error_code ret; 561 hdb_master_key mkey; 562 563 ret = hdb_process_master_key(context, 0, key, 0, &mkey); 564 if (ret) 565 return ret; 566 db->hdb_master_key = mkey; 567#if 0 /* XXX - why? */ 568 des_set_random_generator_seed(key.keyvalue.data); 569#endif 570 db->hdb_master_key_set = 1; 571 return 0; 572} 573 574krb5_error_code 575hdb_set_master_keyfile (krb5_context context, 576 HDB *db, 577 const char *keyfile) 578{ 579 hdb_master_key key; 580 krb5_error_code ret; 581 582 ret = hdb_read_master_key(context, keyfile, &key); 583 if (ret) { 584 if (ret != ENOENT) 585 return ret; 586 krb5_clear_error_message(context); 587 return 0; 588 } 589 db->hdb_master_key = key; 590 db->hdb_master_key_set = 1; 591 return ret; 592} 593 594krb5_error_code 595hdb_clear_master_key (krb5_context context, 596 HDB *db) 597{ 598 if (db->hdb_master_key_set) { 599 hdb_free_master_key(context, db->hdb_master_key); 600 db->hdb_master_key_set = 0; 601 } 602 return 0; 603} 604