1 /* $NetBSD: authfile.c,v 1.8 2013/11/08 19:18:24 christos Exp $ */ 2 /* $OpenBSD: authfile.c,v 1.97 2013/05/17 00:13:13 djm Exp $ */ 3 /* 4 * Author: Tatu Ylonen <ylo@cs.hut.fi> 5 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 6 * All rights reserved 7 * This file contains functions for reading and writing identity files, and 8 * for reading the passphrase from the user. 9 * 10 * As far as I am concerned, the code I have written for this software 11 * can be used freely for any purpose. Any derived versions of this 12 * software must be clearly marked as such, and if the derived work is 13 * incompatible with the protocol description in the RFC file, it must be 14 * called by a name other than "ssh" or "Secure Shell". 15 * 16 * 17 * Copyright (c) 2000 Markus Friedl. All rights reserved. 18 * 19 * Redistribution and use in source and binary forms, with or without 20 * modification, are permitted provided that the following conditions 21 * are met: 22 * 1. Redistributions of source code must retain the above copyright 23 * notice, this list of conditions and the following disclaimer. 24 * 2. Redistributions in binary form must reproduce the above copyright 25 * notice, this list of conditions and the following disclaimer in the 26 * documentation and/or other materials provided with the distribution. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 29 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 30 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 31 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 33 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 37 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 #include "includes.h" 41 __RCSID("$NetBSD: authfile.c,v 1.8 2013/11/08 19:18:24 christos Exp $"); 42 #include <sys/types.h> 43 #include <sys/stat.h> 44 #include <sys/param.h> 45 #include <sys/uio.h> 46 47 #include <openssl/err.h> 48 #include <openssl/evp.h> 49 #include <openssl/pem.h> 50 51 #include <errno.h> 52 #include <fcntl.h> 53 #include <stdio.h> 54 #include <stdlib.h> 55 #include <string.h> 56 #include <unistd.h> 57 58 #include "xmalloc.h" 59 #include "cipher.h" 60 #include "buffer.h" 61 #include "key.h" 62 #include "ssh.h" 63 #include "log.h" 64 #include "authfile.h" 65 #include "rsa.h" 66 #include "misc.h" 67 #include "atomicio.h" 68 69 #define MAX_KEY_FILE_SIZE (1024 * 1024) 70 71 /* Version identification string for SSH v1 identity files. */ 72 static const char authfile_id_string[] = 73 "SSH PRIVATE KEY FILE FORMAT 1.1\n"; 74 75 /* 76 * Serialises the authentication (private) key to a blob, encrypting it with 77 * passphrase. The identification of the blob (lowest 64 bits of n) will 78 * precede the key to provide identification of the key without needing a 79 * passphrase. 80 */ 81 static int 82 key_private_rsa1_to_blob(Key *key, Buffer *blob, const char *passphrase, 83 const char *comment) 84 { 85 Buffer buffer, encrypted; 86 u_char buf[100], *cp; 87 int i, cipher_num; 88 CipherContext ciphercontext; 89 const Cipher *cipher; 90 u_int32_t rnd; 91 92 /* 93 * If the passphrase is empty, use SSH_CIPHER_NONE to ease converting 94 * to another cipher; otherwise use SSH_AUTHFILE_CIPHER. 95 */ 96 cipher_num = (strcmp(passphrase, "") == 0) ? 97 SSH_CIPHER_NONE : SSH_AUTHFILE_CIPHER; 98 if ((cipher = cipher_by_number(cipher_num)) == NULL) 99 fatal("save_private_key_rsa: bad cipher"); 100 101 /* This buffer is used to built the secret part of the private key. */ 102 buffer_init(&buffer); 103 104 /* Put checkbytes for checking passphrase validity. */ 105 rnd = arc4random(); 106 buf[0] = rnd & 0xff; 107 buf[1] = (rnd >> 8) & 0xff; 108 buf[2] = buf[0]; 109 buf[3] = buf[1]; 110 buffer_append(&buffer, buf, 4); 111 112 /* 113 * Store the private key (n and e will not be stored because they 114 * will be stored in plain text, and storing them also in encrypted 115 * format would just give known plaintext). 116 */ 117 buffer_put_bignum(&buffer, key->rsa->d); 118 buffer_put_bignum(&buffer, key->rsa->iqmp); 119 buffer_put_bignum(&buffer, key->rsa->q); /* reverse from SSL p */ 120 buffer_put_bignum(&buffer, key->rsa->p); /* reverse from SSL q */ 121 122 /* Pad the part to be encrypted until its size is a multiple of 8. */ 123 while (buffer_len(&buffer) % 8 != 0) 124 buffer_put_char(&buffer, 0); 125 126 /* This buffer will be used to contain the data in the file. */ 127 buffer_init(&encrypted); 128 129 /* First store keyfile id string. */ 130 for (i = 0; authfile_id_string[i]; i++) 131 buffer_put_char(&encrypted, authfile_id_string[i]); 132 buffer_put_char(&encrypted, 0); 133 134 /* Store cipher type. */ 135 buffer_put_char(&encrypted, cipher_num); 136 buffer_put_int(&encrypted, 0); /* For future extension */ 137 138 /* Store public key. This will be in plain text. */ 139 buffer_put_int(&encrypted, BN_num_bits(key->rsa->n)); 140 buffer_put_bignum(&encrypted, key->rsa->n); 141 buffer_put_bignum(&encrypted, key->rsa->e); 142 buffer_put_cstring(&encrypted, comment); 143 144 /* Allocate space for the private part of the key in the buffer. */ 145 cp = buffer_append_space(&encrypted, buffer_len(&buffer)); 146 147 cipher_set_key_string(&ciphercontext, cipher, passphrase, 148 CIPHER_ENCRYPT); 149 cipher_crypt(&ciphercontext, cp, 150 buffer_ptr(&buffer), buffer_len(&buffer), 0, 0); 151 cipher_cleanup(&ciphercontext); 152 memset(&ciphercontext, 0, sizeof(ciphercontext)); 153 154 /* Destroy temporary data. */ 155 memset(buf, 0, sizeof(buf)); 156 buffer_free(&buffer); 157 158 buffer_append(blob, buffer_ptr(&encrypted), buffer_len(&encrypted)); 159 buffer_free(&encrypted); 160 161 return 1; 162 } 163 164 /* convert SSH v2 key in OpenSSL PEM format */ 165 static int 166 key_private_pem_to_blob(Key *key, Buffer *blob, const char *_passphrase, 167 const char *comment) 168 { 169 int success = 0; 170 int blen, len = strlen(_passphrase); 171 u_char *passphrase = (len > 0) ? __UNCONST(_passphrase) : NULL; 172 const EVP_CIPHER *cipher = (len > 0) ? EVP_aes_128_cbc() : NULL; 173 const u_char *bptr; 174 BIO *bio; 175 176 if (len > 0 && len <= 4) { 177 error("passphrase too short: have %d bytes, need > 4", len); 178 return 0; 179 } 180 if ((bio = BIO_new(BIO_s_mem())) == NULL) { 181 error("%s: BIO_new failed", __func__); 182 return 0; 183 } 184 switch (key->type) { 185 case KEY_DSA: 186 success = PEM_write_bio_DSAPrivateKey(bio, key->dsa, 187 cipher, passphrase, len, NULL, NULL); 188 break; 189 case KEY_ECDSA: 190 success = PEM_write_bio_ECPrivateKey(bio, key->ecdsa, 191 cipher, passphrase, len, NULL, NULL); 192 break; 193 case KEY_RSA: 194 success = PEM_write_bio_RSAPrivateKey(bio, key->rsa, 195 cipher, passphrase, len, NULL, NULL); 196 break; 197 } 198 if (success) { 199 if ((blen = BIO_get_mem_data(bio, &bptr)) <= 0) 200 success = 0; 201 else 202 buffer_append(blob, bptr, blen); 203 } 204 BIO_free(bio); 205 return success; 206 } 207 208 /* Save a key blob to a file */ 209 static int 210 key_save_private_blob(Buffer *keybuf, const char *filename) 211 { 212 int fd; 213 214 if ((fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0600)) < 0) { 215 error("open %s failed: %s.", filename, strerror(errno)); 216 return 0; 217 } 218 if (atomicio(vwrite, fd, buffer_ptr(keybuf), 219 buffer_len(keybuf)) != buffer_len(keybuf)) { 220 error("write to key file %s failed: %s", filename, 221 strerror(errno)); 222 close(fd); 223 unlink(filename); 224 return 0; 225 } 226 close(fd); 227 return 1; 228 } 229 230 /* Serialise "key" to buffer "blob" */ 231 static int 232 key_private_to_blob(Key *key, Buffer *blob, const char *passphrase, 233 const char *comment) 234 { 235 switch (key->type) { 236 case KEY_RSA1: 237 return key_private_rsa1_to_blob(key, blob, passphrase, comment); 238 case KEY_DSA: 239 case KEY_ECDSA: 240 case KEY_RSA: 241 return key_private_pem_to_blob(key, blob, passphrase, comment); 242 default: 243 error("%s: cannot save key type %d", __func__, key->type); 244 return 0; 245 } 246 } 247 248 int 249 key_save_private(Key *key, const char *filename, const char *passphrase, 250 const char *comment) 251 { 252 Buffer keyblob; 253 int success = 0; 254 255 buffer_init(&keyblob); 256 if (!key_private_to_blob(key, &keyblob, passphrase, comment)) 257 goto out; 258 if (!key_save_private_blob(&keyblob, filename)) 259 goto out; 260 success = 1; 261 out: 262 buffer_free(&keyblob); 263 return success; 264 } 265 266 /* 267 * Parse the public, unencrypted portion of a RSA1 key. 268 */ 269 static Key * 270 key_parse_public_rsa1(Buffer *blob, char **commentp) 271 { 272 Key *pub; 273 Buffer copy; 274 275 /* Check that it is at least big enough to contain the ID string. */ 276 if (buffer_len(blob) < sizeof(authfile_id_string)) { 277 debug3("Truncated RSA1 identifier"); 278 return NULL; 279 } 280 281 /* 282 * Make sure it begins with the id string. Consume the id string 283 * from the buffer. 284 */ 285 if (memcmp(buffer_ptr(blob), authfile_id_string, 286 sizeof(authfile_id_string)) != 0) { 287 debug3("Incorrect RSA1 identifier"); 288 return NULL; 289 } 290 buffer_init(©); 291 buffer_append(©, buffer_ptr(blob), buffer_len(blob)); 292 buffer_consume(©, sizeof(authfile_id_string)); 293 294 /* Skip cipher type and reserved data. */ 295 (void) buffer_get_char(©); /* cipher type */ 296 (void) buffer_get_int(©); /* reserved */ 297 298 /* Read the public key from the buffer. */ 299 (void) buffer_get_int(©); 300 pub = key_new(KEY_RSA1); 301 buffer_get_bignum(©, pub->rsa->n); 302 buffer_get_bignum(©, pub->rsa->e); 303 if (commentp) 304 *commentp = buffer_get_string(©, NULL); 305 /* The encrypted private part is not parsed by this function. */ 306 buffer_free(©); 307 308 return pub; 309 } 310 311 /* Load a key from a fd into a buffer */ 312 int 313 key_load_file(int fd, const char *filename, Buffer *blob) 314 { 315 u_char buf[1024]; 316 size_t len; 317 struct stat st; 318 319 if (fstat(fd, &st) < 0) { 320 error("%s: fstat of key file %.200s%sfailed: %.100s", __func__, 321 filename == NULL ? "" : filename, 322 filename == NULL ? "" : " ", 323 strerror(errno)); 324 return 0; 325 } 326 if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 && 327 st.st_size > MAX_KEY_FILE_SIZE) { 328 toobig: 329 error("%s: key file %.200s%stoo large", __func__, 330 filename == NULL ? "" : filename, 331 filename == NULL ? "" : " "); 332 return 0; 333 } 334 buffer_clear(blob); 335 for (;;) { 336 if ((len = atomicio(read, fd, buf, sizeof(buf))) == 0) { 337 if (errno == EPIPE) 338 break; 339 debug("%s: read from key file %.200s%sfailed: %.100s", 340 __func__, filename == NULL ? "" : filename, 341 filename == NULL ? "" : " ", strerror(errno)); 342 buffer_clear(blob); 343 bzero(buf, sizeof(buf)); 344 return 0; 345 } 346 buffer_append(blob, buf, len); 347 if (buffer_len(blob) > MAX_KEY_FILE_SIZE) { 348 buffer_clear(blob); 349 bzero(buf, sizeof(buf)); 350 goto toobig; 351 } 352 } 353 bzero(buf, sizeof(buf)); 354 if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 && 355 st.st_size != buffer_len(blob)) { 356 debug("%s: key file %.200s%schanged size while reading", 357 __func__, filename == NULL ? "" : filename, 358 filename == NULL ? "" : " "); 359 buffer_clear(blob); 360 return 0; 361 } 362 363 return 1; 364 } 365 366 /* 367 * Loads the public part of the ssh v1 key file. Returns NULL if an error was 368 * encountered (the file does not exist or is not readable), and the key 369 * otherwise. 370 */ 371 static Key * 372 key_load_public_rsa1(int fd, const char *filename, char **commentp) 373 { 374 Buffer buffer; 375 Key *pub; 376 377 buffer_init(&buffer); 378 if (!key_load_file(fd, filename, &buffer)) { 379 buffer_free(&buffer); 380 return NULL; 381 } 382 383 pub = key_parse_public_rsa1(&buffer, commentp); 384 if (pub == NULL) 385 debug3("Could not load \"%s\" as a RSA1 public key", filename); 386 buffer_free(&buffer); 387 return pub; 388 } 389 390 /* load public key from private-key file, works only for SSH v1 */ 391 Key * 392 key_load_public_type(int type, const char *filename, char **commentp) 393 { 394 Key *pub; 395 int fd; 396 397 if (type == KEY_RSA1) { 398 fd = open(filename, O_RDONLY); 399 if (fd < 0) 400 return NULL; 401 pub = key_load_public_rsa1(fd, filename, commentp); 402 close(fd); 403 return pub; 404 } 405 return NULL; 406 } 407 408 static Key * 409 key_parse_private_rsa1(Buffer *blob, const char *passphrase, char **commentp) 410 { 411 int check1, check2, cipher_type; 412 Buffer decrypted; 413 u_char *cp; 414 CipherContext ciphercontext; 415 const Cipher *cipher; 416 Key *prv = NULL; 417 Buffer copy; 418 419 /* Check that it is at least big enough to contain the ID string. */ 420 if (buffer_len(blob) < sizeof(authfile_id_string)) { 421 debug3("Truncated RSA1 identifier"); 422 return NULL; 423 } 424 425 /* 426 * Make sure it begins with the id string. Consume the id string 427 * from the buffer. 428 */ 429 if (memcmp(buffer_ptr(blob), authfile_id_string, 430 sizeof(authfile_id_string)) != 0) { 431 debug3("Incorrect RSA1 identifier"); 432 return NULL; 433 } 434 buffer_init(©); 435 buffer_append(©, buffer_ptr(blob), buffer_len(blob)); 436 buffer_consume(©, sizeof(authfile_id_string)); 437 438 /* Read cipher type. */ 439 cipher_type = buffer_get_char(©); 440 (void) buffer_get_int(©); /* Reserved data. */ 441 442 /* Read the public key from the buffer. */ 443 (void) buffer_get_int(©); 444 prv = key_new_private(KEY_RSA1); 445 446 buffer_get_bignum(©, prv->rsa->n); 447 buffer_get_bignum(©, prv->rsa->e); 448 if (commentp) 449 *commentp = buffer_get_string(©, NULL); 450 else 451 (void)buffer_get_string_ptr(©, NULL); 452 453 /* Check that it is a supported cipher. */ 454 cipher = cipher_by_number(cipher_type); 455 if (cipher == NULL) { 456 debug("Unsupported RSA1 cipher %d", cipher_type); 457 buffer_free(©); 458 goto fail; 459 } 460 /* Initialize space for decrypted data. */ 461 buffer_init(&decrypted); 462 cp = buffer_append_space(&decrypted, buffer_len(©)); 463 464 /* Rest of the buffer is encrypted. Decrypt it using the passphrase. */ 465 cipher_set_key_string(&ciphercontext, cipher, passphrase, 466 CIPHER_DECRYPT); 467 cipher_crypt(&ciphercontext, cp, 468 buffer_ptr(©), buffer_len(©), 0, 0); 469 cipher_cleanup(&ciphercontext); 470 memset(&ciphercontext, 0, sizeof(ciphercontext)); 471 buffer_free(©); 472 473 check1 = buffer_get_char(&decrypted); 474 check2 = buffer_get_char(&decrypted); 475 if (check1 != buffer_get_char(&decrypted) || 476 check2 != buffer_get_char(&decrypted)) { 477 if (strcmp(passphrase, "") != 0) 478 debug("Bad passphrase supplied for RSA1 key"); 479 /* Bad passphrase. */ 480 buffer_free(&decrypted); 481 goto fail; 482 } 483 /* Read the rest of the private key. */ 484 buffer_get_bignum(&decrypted, prv->rsa->d); 485 buffer_get_bignum(&decrypted, prv->rsa->iqmp); /* u */ 486 /* in SSL and SSH v1 p and q are exchanged */ 487 buffer_get_bignum(&decrypted, prv->rsa->q); /* p */ 488 buffer_get_bignum(&decrypted, prv->rsa->p); /* q */ 489 490 /* calculate p-1 and q-1 */ 491 rsa_generate_additional_parameters(prv->rsa); 492 493 buffer_free(&decrypted); 494 495 /* enable blinding */ 496 if (RSA_blinding_on(prv->rsa, NULL) != 1) { 497 error("%s: RSA_blinding_on failed", __func__); 498 goto fail; 499 } 500 return prv; 501 502 fail: 503 if (commentp != NULL) 504 free(*commentp); 505 key_free(prv); 506 return NULL; 507 } 508 509 static Key * 510 key_parse_private_pem(Buffer *blob, int type, const char *passphrase, 511 char **commentp) 512 { 513 EVP_PKEY *pk = NULL; 514 Key *prv = NULL; 515 const char *name = "<no key>"; 516 BIO *bio; 517 518 if ((bio = BIO_new_mem_buf(buffer_ptr(blob), 519 buffer_len(blob))) == NULL) { 520 error("%s: BIO_new_mem_buf failed", __func__); 521 return NULL; 522 } 523 524 pk = PEM_read_bio_PrivateKey(bio, NULL, NULL, __UNCONST(passphrase)); 525 BIO_free(bio); 526 if (pk == NULL) { 527 debug("%s: PEM_read_PrivateKey failed", __func__); 528 (void)ERR_get_error(); 529 } else if (pk->type == EVP_PKEY_RSA && 530 (type == KEY_UNSPEC||type==KEY_RSA)) { 531 prv = key_new(KEY_UNSPEC); 532 prv->rsa = EVP_PKEY_get1_RSA(pk); 533 prv->type = KEY_RSA; 534 name = "rsa w/o comment"; 535 #ifdef DEBUG_PK 536 RSA_print_fp(stderr, prv->rsa, 8); 537 #endif 538 if (RSA_blinding_on(prv->rsa, NULL) != 1) { 539 error("%s: RSA_blinding_on failed", __func__); 540 key_free(prv); 541 prv = NULL; 542 } 543 } else if (pk->type == EVP_PKEY_DSA && 544 (type == KEY_UNSPEC||type==KEY_DSA)) { 545 prv = key_new(KEY_UNSPEC); 546 prv->dsa = EVP_PKEY_get1_DSA(pk); 547 prv->type = KEY_DSA; 548 name = "dsa w/o comment"; 549 #ifdef DEBUG_PK 550 DSA_print_fp(stderr, prv->dsa, 8); 551 #endif 552 } else if (pk->type == EVP_PKEY_EC && 553 (type == KEY_UNSPEC||type==KEY_ECDSA)) { 554 prv = key_new(KEY_UNSPEC); 555 prv->ecdsa = EVP_PKEY_get1_EC_KEY(pk); 556 prv->type = KEY_ECDSA; 557 if ((prv->ecdsa_nid = key_ecdsa_key_to_nid(prv->ecdsa)) == -1 || 558 key_curve_nid_to_name(prv->ecdsa_nid) == NULL || 559 key_ec_validate_public(EC_KEY_get0_group(prv->ecdsa), 560 EC_KEY_get0_public_key(prv->ecdsa)) != 0 || 561 key_ec_validate_private(prv->ecdsa) != 0) { 562 error("%s: bad ECDSA key", __func__); 563 key_free(prv); 564 prv = NULL; 565 } 566 name = "ecdsa w/o comment"; 567 #ifdef DEBUG_PK 568 if (prv != NULL && prv->ecdsa != NULL) 569 key_dump_ec_key(prv->ecdsa); 570 #endif 571 } else { 572 error("%s: PEM_read_PrivateKey: mismatch or " 573 "unknown EVP_PKEY save_type %d", __func__, pk->save_type); 574 } 575 if (pk != NULL) 576 EVP_PKEY_free(pk); 577 if (prv != NULL && commentp) 578 *commentp = xstrdup(name); 579 debug("read PEM private key done: type %s", 580 prv ? key_type(prv) : "<unknown>"); 581 return prv; 582 } 583 584 Key * 585 key_load_private_pem(int fd, int type, const char *passphrase, 586 char **commentp) 587 { 588 Buffer buffer; 589 Key *prv; 590 591 buffer_init(&buffer); 592 if (!key_load_file(fd, NULL, &buffer)) { 593 buffer_free(&buffer); 594 return NULL; 595 } 596 prv = key_parse_private_pem(&buffer, type, passphrase, commentp); 597 buffer_free(&buffer); 598 return prv; 599 } 600 601 int 602 key_perm_ok(int fd, const char *filename) 603 { 604 struct stat st; 605 606 if (fstat(fd, &st) < 0) 607 return 0; 608 /* 609 * if a key owned by the user is accessed, then we check the 610 * permissions of the file. if the key owned by a different user, 611 * then we don't care. 612 */ 613 if ((st.st_uid == getuid()) && (st.st_mode & 077) != 0) { 614 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); 615 error("@ WARNING: UNPROTECTED PRIVATE KEY FILE! @"); 616 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); 617 error("Permissions 0%3.3o for '%s' are too open.", 618 (u_int)st.st_mode & 0777, filename); 619 error("It is recommended that your private key files are NOT accessible by others."); 620 error("This private key will be ignored."); 621 return 0; 622 } 623 return 1; 624 } 625 626 static Key * 627 key_parse_private_type(Buffer *blob, int type, const char *passphrase, 628 char **commentp) 629 { 630 switch (type) { 631 case KEY_RSA1: 632 return key_parse_private_rsa1(blob, passphrase, commentp); 633 case KEY_DSA: 634 case KEY_ECDSA: 635 case KEY_RSA: 636 case KEY_UNSPEC: 637 return key_parse_private_pem(blob, type, passphrase, commentp); 638 default: 639 error("%s: cannot parse key type %d", __func__, type); 640 break; 641 } 642 return NULL; 643 } 644 645 Key * 646 key_load_private_type(int type, const char *filename, const char *passphrase, 647 char **commentp, int *perm_ok) 648 { 649 int fd; 650 Key *ret; 651 Buffer buffer; 652 653 fd = open(filename, O_RDONLY); 654 if (fd < 0) { 655 debug("could not open key file '%s': %s", filename, 656 strerror(errno)); 657 if (perm_ok != NULL) 658 *perm_ok = 0; 659 return NULL; 660 } 661 if (!key_perm_ok(fd, filename)) { 662 if (perm_ok != NULL) 663 *perm_ok = 0; 664 error("bad permissions: ignore key: %s", filename); 665 close(fd); 666 return NULL; 667 } 668 if (perm_ok != NULL) 669 *perm_ok = 1; 670 671 buffer_init(&buffer); 672 if (!key_load_file(fd, filename, &buffer)) { 673 buffer_free(&buffer); 674 close(fd); 675 return NULL; 676 } 677 close(fd); 678 ret = key_parse_private_type(&buffer, type, passphrase, commentp); 679 buffer_free(&buffer); 680 return ret; 681 } 682 683 Key * 684 key_parse_private(Buffer *buffer, const char *filename, 685 const char *passphrase, char **commentp) 686 { 687 Key *pub, *prv; 688 689 /* it's a SSH v1 key if the public key part is readable */ 690 pub = key_parse_public_rsa1(buffer, commentp); 691 if (pub == NULL) { 692 prv = key_parse_private_type(buffer, KEY_UNSPEC, 693 passphrase, NULL); 694 /* use the filename as a comment for PEM */ 695 if (commentp && prv) 696 *commentp = xstrdup(filename); 697 } else { 698 key_free(pub); 699 /* key_parse_public_rsa1() has already loaded the comment */ 700 prv = key_parse_private_type(buffer, KEY_RSA1, passphrase, 701 NULL); 702 } 703 return prv; 704 } 705 706 Key * 707 key_load_private(const char *filename, const char *passphrase, 708 char **commentp) 709 { 710 Key *prv; 711 Buffer buffer; 712 int fd; 713 714 fd = open(filename, O_RDONLY); 715 if (fd < 0) { 716 debug("could not open key file '%s': %s", filename, 717 strerror(errno)); 718 return NULL; 719 } 720 if (!key_perm_ok(fd, filename)) { 721 error("bad permissions: ignore key: %s", filename); 722 close(fd); 723 return NULL; 724 } 725 726 buffer_init(&buffer); 727 if (!key_load_file(fd, filename, &buffer)) { 728 buffer_free(&buffer); 729 close(fd); 730 return NULL; 731 } 732 close(fd); 733 734 prv = key_parse_private(&buffer, filename, passphrase, commentp); 735 buffer_free(&buffer); 736 return prv; 737 } 738 739 static int 740 key_try_load_public(Key *k, const char *filename, char **commentp) 741 { 742 FILE *f; 743 char line[SSH_MAX_PUBKEY_BYTES]; 744 char *cp; 745 u_long linenum = 0; 746 747 f = fopen(filename, "r"); 748 if (f != NULL) { 749 while (read_keyfile_line(f, filename, line, sizeof(line), 750 &linenum) != -1) { 751 cp = line; 752 switch (*cp) { 753 case '#': 754 case '\n': 755 case '\0': 756 continue; 757 } 758 /* Abort loading if this looks like a private key */ 759 if (strncmp(cp, "-----BEGIN", 10) == 0) 760 break; 761 /* Skip leading whitespace. */ 762 for (; *cp && (*cp == ' ' || *cp == '\t'); cp++) 763 ; 764 if (*cp) { 765 if (key_read(k, &cp) == 1) { 766 cp[strcspn(cp, "\r\n")] = '\0'; 767 if (commentp) { 768 *commentp = xstrdup(*cp ? 769 cp : filename); 770 } 771 fclose(f); 772 return 1; 773 } 774 } 775 } 776 fclose(f); 777 } 778 return 0; 779 } 780 781 /* load public key from ssh v1 private or any pubkey file */ 782 Key * 783 key_load_public(const char *filename, char **commentp) 784 { 785 Key *pub; 786 char file[MAXPATHLEN]; 787 788 /* try rsa1 private key */ 789 pub = key_load_public_type(KEY_RSA1, filename, commentp); 790 if (pub != NULL) 791 return pub; 792 793 /* try rsa1 public key */ 794 pub = key_new(KEY_RSA1); 795 if (key_try_load_public(pub, filename, commentp) == 1) 796 return pub; 797 key_free(pub); 798 799 /* try ssh2 public key */ 800 pub = key_new(KEY_UNSPEC); 801 if (key_try_load_public(pub, filename, commentp) == 1) 802 return pub; 803 if ((strlcpy(file, filename, sizeof file) < sizeof(file)) && 804 (strlcat(file, ".pub", sizeof file) < sizeof(file)) && 805 (key_try_load_public(pub, file, commentp) == 1)) 806 return pub; 807 key_free(pub); 808 return NULL; 809 } 810 811 /* Load the certificate associated with the named private key */ 812 Key * 813 key_load_cert(const char *filename) 814 { 815 Key *pub; 816 char *file; 817 818 pub = key_new(KEY_UNSPEC); 819 xasprintf(&file, "%s-cert.pub", filename); 820 if (key_try_load_public(pub, file, NULL) == 1) { 821 free(file); 822 return pub; 823 } 824 free(file); 825 key_free(pub); 826 return NULL; 827 } 828 829 /* Load private key and certificate */ 830 Key * 831 key_load_private_cert(int type, const char *filename, const char *passphrase, 832 int *perm_ok) 833 { 834 Key *key, *pub; 835 836 switch (type) { 837 case KEY_RSA: 838 case KEY_DSA: 839 case KEY_ECDSA: 840 break; 841 default: 842 error("%s: unsupported key type", __func__); 843 return NULL; 844 } 845 846 if ((key = key_load_private_type(type, filename, 847 passphrase, NULL, perm_ok)) == NULL) 848 return NULL; 849 850 if ((pub = key_load_cert(filename)) == NULL) { 851 key_free(key); 852 return NULL; 853 } 854 855 /* Make sure the private key matches the certificate */ 856 if (key_equal_public(key, pub) == 0) { 857 error("%s: certificate does not match private key %s", 858 __func__, filename); 859 } else if (key_to_certified(key, key_cert_is_legacy(pub)) != 0) { 860 error("%s: key_to_certified failed", __func__); 861 } else { 862 key_cert_copy(pub, key); 863 key_free(pub); 864 return key; 865 } 866 867 key_free(key); 868 key_free(pub); 869 return NULL; 870 } 871 872 /* 873 * Returns 1 if the specified "key" is listed in the file "filename", 874 * 0 if the key is not listed or -1 on error. 875 * If strict_type is set then the key type must match exactly, 876 * otherwise a comparison that ignores certficiate data is performed. 877 */ 878 int 879 key_in_file(Key *key, const char *filename, int strict_type) 880 { 881 FILE *f; 882 char line[SSH_MAX_PUBKEY_BYTES]; 883 char *cp; 884 u_long linenum = 0; 885 int ret = 0; 886 Key *pub; 887 int (*key_compare)(const Key *, const Key *) = strict_type ? 888 key_equal : key_equal_public; 889 890 if ((f = fopen(filename, "r")) == NULL) { 891 if (errno == ENOENT) { 892 debug("%s: keyfile \"%s\" missing", __func__, filename); 893 return 0; 894 } else { 895 error("%s: could not open keyfile \"%s\": %s", __func__, 896 filename, strerror(errno)); 897 return -1; 898 } 899 } 900 901 while (read_keyfile_line(f, filename, line, sizeof(line), 902 &linenum) != -1) { 903 cp = line; 904 905 /* Skip leading whitespace. */ 906 for (; *cp && (*cp == ' ' || *cp == '\t'); cp++) 907 ; 908 909 /* Skip comments and empty lines */ 910 switch (*cp) { 911 case '#': 912 case '\n': 913 case '\0': 914 continue; 915 } 916 917 pub = key_new(KEY_UNSPEC); 918 if (key_read(pub, &cp) != 1) { 919 key_free(pub); 920 continue; 921 } 922 if (key_compare(key, pub)) { 923 ret = 1; 924 key_free(pub); 925 break; 926 } 927 key_free(pub); 928 } 929 fclose(f); 930 return ret; 931 } 932 933