1 /* $OpenBSD: ssh-add.c,v 1.123 2015/07/03 03:43:18 djm Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * Adds an identity to the authentication server, or removes an identity. 7 * 8 * As far as I am concerned, the code I have written for this software 9 * can be used freely for any purpose. Any derived versions of this 10 * software must be clearly marked as such, and if the derived work is 11 * incompatible with the protocol description in the RFC file, it must be 12 * called by a name other than "ssh" or "Secure Shell". 13 * 14 * SSH2 implementation, 15 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions 19 * are met: 20 * 1. Redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer. 22 * 2. Redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38 #include "includes.h" 39 40 #include <sys/types.h> 41 #include <sys/stat.h> 42 43 #include <openssl/evp.h> 44 #include "openbsd-compat/openssl-compat.h" 45 46 #include <errno.h> 47 #include <fcntl.h> 48 #include <pwd.h> 49 #include <stdarg.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <unistd.h> 54 #include <limits.h> 55 56 #include "xmalloc.h" 57 #include "ssh.h" 58 #include "rsa.h" 59 #include "log.h" 60 #include "sshkey.h" 61 #include "sshbuf.h" 62 #include "authfd.h" 63 #include "authfile.h" 64 #include "pathnames.h" 65 #include "misc.h" 66 #include "ssherr.h" 67 #include "digest.h" 68 69 /* argv0 */ 70 extern char *__progname; 71 72 /* Default files to add */ 73 static char *default_files[] = { 74 #ifdef WITH_OPENSSL 75 _PATH_SSH_CLIENT_ID_RSA, 76 _PATH_SSH_CLIENT_ID_DSA, 77 #ifdef OPENSSL_HAS_ECC 78 _PATH_SSH_CLIENT_ID_ECDSA, 79 #endif 80 #endif /* WITH_OPENSSL */ 81 _PATH_SSH_CLIENT_ID_ED25519, 82 #ifdef WITH_SSH1 83 _PATH_SSH_CLIENT_IDENTITY, 84 #endif 85 NULL 86 }; 87 88 static int fingerprint_hash = SSH_FP_HASH_DEFAULT; 89 90 /* Default lifetime (0 == forever) */ 91 static int lifetime = 0; 92 93 /* User has to confirm key use */ 94 static int confirm = 0; 95 96 /* we keep a cache of one passphrases */ 97 static char *pass = NULL; 98 static void 99 clear_pass(void) 100 { 101 if (pass) { 102 explicit_bzero(pass, strlen(pass)); 103 free(pass); 104 pass = NULL; 105 } 106 } 107 108 static int 109 delete_file(int agent_fd, const char *filename, int key_only) 110 { 111 struct sshkey *public, *cert = NULL; 112 char *certpath = NULL, *comment = NULL; 113 int r, ret = -1; 114 115 if ((r = sshkey_load_public(filename, &public, &comment)) != 0) { 116 printf("Bad key file %s: %s\n", filename, ssh_err(r)); 117 return -1; 118 } 119 if ((r = ssh_remove_identity(agent_fd, public)) == 0) { 120 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment); 121 ret = 0; 122 } else 123 fprintf(stderr, "Could not remove identity \"%s\": %s\n", 124 filename, ssh_err(r)); 125 126 if (key_only) 127 goto out; 128 129 /* Now try to delete the corresponding certificate too */ 130 free(comment); 131 comment = NULL; 132 xasprintf(&certpath, "%s-cert.pub", filename); 133 if ((r = sshkey_load_public(certpath, &cert, &comment)) != 0) { 134 if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT) 135 error("Failed to load certificate \"%s\": %s", 136 certpath, ssh_err(r)); 137 goto out; 138 } 139 140 if (!sshkey_equal_public(cert, public)) 141 fatal("Certificate %s does not match private key %s", 142 certpath, filename); 143 144 if ((r = ssh_remove_identity(agent_fd, cert)) == 0) { 145 fprintf(stderr, "Identity removed: %s (%s)\n", certpath, 146 comment); 147 ret = 0; 148 } else 149 fprintf(stderr, "Could not remove identity \"%s\": %s\n", 150 certpath, ssh_err(r)); 151 152 out: 153 if (cert != NULL) 154 sshkey_free(cert); 155 if (public != NULL) 156 sshkey_free(public); 157 free(certpath); 158 free(comment); 159 160 return ret; 161 } 162 163 /* Send a request to remove all identities. */ 164 static int 165 delete_all(int agent_fd) 166 { 167 int ret = -1; 168 169 if (ssh_remove_all_identities(agent_fd, 2) == 0) 170 ret = 0; 171 /* ignore error-code for ssh1 */ 172 ssh_remove_all_identities(agent_fd, 1); 173 174 if (ret == 0) 175 fprintf(stderr, "All identities removed.\n"); 176 else 177 fprintf(stderr, "Failed to remove all identities.\n"); 178 179 return ret; 180 } 181 182 static int 183 add_file(int agent_fd, const char *filename, int key_only) 184 { 185 struct sshkey *private, *cert; 186 char *comment = NULL; 187 char msg[1024], *certpath = NULL; 188 int r, fd, ret = -1; 189 struct sshbuf *keyblob; 190 191 if (strcmp(filename, "-") == 0) { 192 fd = STDIN_FILENO; 193 filename = "(stdin)"; 194 } else if ((fd = open(filename, O_RDONLY)) < 0) { 195 perror(filename); 196 return -1; 197 } 198 199 /* 200 * Since we'll try to load a keyfile multiple times, permission errors 201 * will occur multiple times, so check perms first and bail if wrong. 202 */ 203 if (fd != STDIN_FILENO) { 204 if (sshkey_perm_ok(fd, filename) != 0) { 205 close(fd); 206 return -1; 207 } 208 } 209 if ((keyblob = sshbuf_new()) == NULL) 210 fatal("%s: sshbuf_new failed", __func__); 211 if ((r = sshkey_load_file(fd, keyblob)) != 0) { 212 fprintf(stderr, "Error loading key \"%s\": %s\n", 213 filename, ssh_err(r)); 214 sshbuf_free(keyblob); 215 close(fd); 216 return -1; 217 } 218 close(fd); 219 220 /* At first, try empty passphrase */ 221 if ((r = sshkey_parse_private_fileblob(keyblob, "", filename, 222 &private, &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) { 223 fprintf(stderr, "Error loading key \"%s\": %s\n", 224 filename, ssh_err(r)); 225 goto fail_load; 226 } 227 /* try last */ 228 if (private == NULL && pass != NULL) { 229 if ((r = sshkey_parse_private_fileblob(keyblob, pass, filename, 230 &private, &comment)) != 0 && 231 r != SSH_ERR_KEY_WRONG_PASSPHRASE) { 232 fprintf(stderr, "Error loading key \"%s\": %s\n", 233 filename, ssh_err(r)); 234 goto fail_load; 235 } 236 } 237 if (comment == NULL) 238 comment = xstrdup(filename); 239 if (private == NULL) { 240 /* clear passphrase since it did not work */ 241 clear_pass(); 242 snprintf(msg, sizeof msg, "Enter passphrase for %.200s%s: ", 243 comment, confirm ? " (will confirm each use)" : ""); 244 for (;;) { 245 pass = read_passphrase(msg, RP_ALLOW_STDIN); 246 if (strcmp(pass, "") == 0) 247 goto fail_load; 248 if ((r = sshkey_parse_private_fileblob(keyblob, pass, 249 filename, &private, NULL)) == 0) 250 break; 251 else if (r != SSH_ERR_KEY_WRONG_PASSPHRASE) { 252 fprintf(stderr, 253 "Error loading key \"%s\": %s\n", 254 filename, ssh_err(r)); 255 fail_load: 256 clear_pass(); 257 free(comment); 258 sshbuf_free(keyblob); 259 return -1; 260 } 261 clear_pass(); 262 snprintf(msg, sizeof msg, 263 "Bad passphrase, try again for %.200s%s: ", comment, 264 confirm ? " (will confirm each use)" : ""); 265 } 266 } 267 sshbuf_free(keyblob); 268 269 if ((r = ssh_add_identity_constrained(agent_fd, private, comment, 270 lifetime, confirm)) == 0) { 271 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment); 272 ret = 0; 273 if (lifetime != 0) 274 fprintf(stderr, 275 "Lifetime set to %d seconds\n", lifetime); 276 if (confirm != 0) 277 fprintf(stderr, 278 "The user must confirm each use of the key\n"); 279 } else { 280 fprintf(stderr, "Could not add identity \"%s\": %s\n", 281 filename, ssh_err(r)); 282 } 283 284 /* Skip trying to load the cert if requested */ 285 if (key_only) 286 goto out; 287 288 /* Now try to add the certificate flavour too */ 289 xasprintf(&certpath, "%s-cert.pub", filename); 290 if ((r = sshkey_load_public(certpath, &cert, NULL)) != 0) { 291 if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT) 292 error("Failed to load certificate \"%s\": %s", 293 certpath, ssh_err(r)); 294 goto out; 295 } 296 297 if (!sshkey_equal_public(cert, private)) { 298 error("Certificate %s does not match private key %s", 299 certpath, filename); 300 sshkey_free(cert); 301 goto out; 302 } 303 304 /* Graft with private bits */ 305 if ((r = sshkey_to_certified(private)) != 0) { 306 error("%s: sshkey_to_certified: %s", __func__, ssh_err(r)); 307 sshkey_free(cert); 308 goto out; 309 } 310 if ((r = sshkey_cert_copy(cert, private)) != 0) { 311 error("%s: key_cert_copy: %s", __func__, ssh_err(r)); 312 sshkey_free(cert); 313 goto out; 314 } 315 sshkey_free(cert); 316 317 if ((r = ssh_add_identity_constrained(agent_fd, private, comment, 318 lifetime, confirm)) != 0) { 319 error("Certificate %s (%s) add failed: %s", certpath, 320 private->cert->key_id, ssh_err(r)); 321 goto out; 322 } 323 fprintf(stderr, "Certificate added: %s (%s)\n", certpath, 324 private->cert->key_id); 325 if (lifetime != 0) 326 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime); 327 if (confirm != 0) 328 fprintf(stderr, "The user must confirm each use of the key\n"); 329 out: 330 free(certpath); 331 free(comment); 332 sshkey_free(private); 333 334 return ret; 335 } 336 337 static int 338 update_card(int agent_fd, int add, const char *id) 339 { 340 char *pin = NULL; 341 int r, ret = -1; 342 343 if (add) { 344 if ((pin = read_passphrase("Enter passphrase for PKCS#11: ", 345 RP_ALLOW_STDIN)) == NULL) 346 return -1; 347 } 348 349 if ((r = ssh_update_card(agent_fd, add, id, pin == NULL ? "" : pin, 350 lifetime, confirm)) == 0) { 351 fprintf(stderr, "Card %s: %s\n", 352 add ? "added" : "removed", id); 353 ret = 0; 354 } else { 355 fprintf(stderr, "Could not %s card \"%s\": %s\n", 356 add ? "add" : "remove", id, ssh_err(r)); 357 ret = -1; 358 } 359 free(pin); 360 return ret; 361 } 362 363 static int 364 list_identities(int agent_fd, int do_fp) 365 { 366 char *fp; 367 int r, had_identities = 0; 368 struct ssh_identitylist *idlist; 369 size_t i; 370 #ifdef WITH_SSH1 371 int version = 1; 372 #else 373 int version = 2; 374 #endif 375 376 for (; version <= 2; version++) { 377 if ((r = ssh_fetch_identitylist(agent_fd, version, 378 &idlist)) != 0) { 379 if (r != SSH_ERR_AGENT_NO_IDENTITIES) 380 fprintf(stderr, "error fetching identities for " 381 "protocol %d: %s\n", version, ssh_err(r)); 382 continue; 383 } 384 for (i = 0; i < idlist->nkeys; i++) { 385 had_identities = 1; 386 if (do_fp) { 387 fp = sshkey_fingerprint(idlist->keys[i], 388 fingerprint_hash, SSH_FP_DEFAULT); 389 printf("%d %s %s (%s)\n", 390 sshkey_size(idlist->keys[i]), 391 fp == NULL ? "(null)" : fp, 392 idlist->comments[i], 393 sshkey_type(idlist->keys[i])); 394 free(fp); 395 } else { 396 if ((r = sshkey_write(idlist->keys[i], 397 stdout)) != 0) { 398 fprintf(stderr, "sshkey_write: %s\n", 399 ssh_err(r)); 400 continue; 401 } 402 fprintf(stdout, " %s\n", idlist->comments[i]); 403 } 404 } 405 ssh_free_identitylist(idlist); 406 } 407 if (!had_identities) { 408 printf("The agent has no identities.\n"); 409 return -1; 410 } 411 return 0; 412 } 413 414 static int 415 lock_agent(int agent_fd, int lock) 416 { 417 char prompt[100], *p1, *p2; 418 int r, passok = 1, ret = -1; 419 420 strlcpy(prompt, "Enter lock password: ", sizeof(prompt)); 421 p1 = read_passphrase(prompt, RP_ALLOW_STDIN); 422 if (lock) { 423 strlcpy(prompt, "Again: ", sizeof prompt); 424 p2 = read_passphrase(prompt, RP_ALLOW_STDIN); 425 if (strcmp(p1, p2) != 0) { 426 fprintf(stderr, "Passwords do not match.\n"); 427 passok = 0; 428 } 429 explicit_bzero(p2, strlen(p2)); 430 free(p2); 431 } 432 if (passok) { 433 if ((r = ssh_lock_agent(agent_fd, lock, p1)) == 0) { 434 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un"); 435 ret = 0; 436 } else { 437 fprintf(stderr, "Failed to %slock agent: %s\n", 438 lock ? "" : "un", ssh_err(r)); 439 } 440 } 441 explicit_bzero(p1, strlen(p1)); 442 free(p1); 443 return (ret); 444 } 445 446 static int 447 do_file(int agent_fd, int deleting, int key_only, char *file) 448 { 449 if (deleting) { 450 if (delete_file(agent_fd, file, key_only) == -1) 451 return -1; 452 } else { 453 if (add_file(agent_fd, file, key_only) == -1) 454 return -1; 455 } 456 return 0; 457 } 458 459 static void 460 usage(void) 461 { 462 fprintf(stderr, "usage: %s [options] [file ...]\n", __progname); 463 fprintf(stderr, "Options:\n"); 464 fprintf(stderr, " -l List fingerprints of all identities.\n"); 465 fprintf(stderr, " -E hash Specify hash algorithm used for fingerprints.\n"); 466 fprintf(stderr, " -L List public key parameters of all identities.\n"); 467 fprintf(stderr, " -k Load only keys and not certificates.\n"); 468 fprintf(stderr, " -c Require confirmation to sign using identities\n"); 469 fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n"); 470 fprintf(stderr, " -d Delete identity.\n"); 471 fprintf(stderr, " -D Delete all identities.\n"); 472 fprintf(stderr, " -x Lock agent.\n"); 473 fprintf(stderr, " -X Unlock agent.\n"); 474 fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n"); 475 fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n"); 476 } 477 478 int 479 main(int argc, char **argv) 480 { 481 extern char *optarg; 482 extern int optind; 483 int agent_fd; 484 char *pkcs11provider = NULL; 485 int r, i, ch, deleting = 0, ret = 0, key_only = 0; 486 int xflag = 0, lflag = 0, Dflag = 0; 487 488 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 489 sanitise_stdfd(); 490 491 __progname = ssh_get_progname(argv[0]); 492 seed_rng(); 493 494 #ifdef WITH_OPENSSL 495 OpenSSL_add_all_algorithms(); 496 #endif 497 498 setvbuf(stdout, NULL, _IOLBF, 0); 499 500 /* First, get a connection to the authentication agent. */ 501 switch (r = ssh_get_authentication_socket(&agent_fd)) { 502 case 0: 503 break; 504 case SSH_ERR_AGENT_NOT_PRESENT: 505 fprintf(stderr, "Could not open a connection to your " 506 "authentication agent.\n"); 507 exit(2); 508 default: 509 fprintf(stderr, "Error connecting to agent: %s\n", ssh_err(r)); 510 exit(2); 511 } 512 513 while ((ch = getopt(argc, argv, "klLcdDxXE:e:s:t:")) != -1) { 514 switch (ch) { 515 case 'E': 516 fingerprint_hash = ssh_digest_alg_by_name(optarg); 517 if (fingerprint_hash == -1) 518 fatal("Invalid hash algorithm \"%s\"", optarg); 519 break; 520 case 'k': 521 key_only = 1; 522 break; 523 case 'l': 524 case 'L': 525 if (lflag != 0) 526 fatal("-%c flag already specified", lflag); 527 lflag = ch; 528 break; 529 case 'x': 530 case 'X': 531 if (xflag != 0) 532 fatal("-%c flag already specified", xflag); 533 xflag = ch; 534 break; 535 case 'c': 536 confirm = 1; 537 break; 538 case 'd': 539 deleting = 1; 540 break; 541 case 'D': 542 Dflag = 1; 543 break; 544 case 's': 545 pkcs11provider = optarg; 546 break; 547 case 'e': 548 deleting = 1; 549 pkcs11provider = optarg; 550 break; 551 case 't': 552 if ((lifetime = convtime(optarg)) == -1) { 553 fprintf(stderr, "Invalid lifetime\n"); 554 ret = 1; 555 goto done; 556 } 557 break; 558 default: 559 usage(); 560 ret = 1; 561 goto done; 562 } 563 } 564 565 if ((xflag != 0) + (lflag != 0) + (Dflag != 0) > 1) 566 fatal("Invalid combination of actions"); 567 else if (xflag) { 568 if (lock_agent(agent_fd, xflag == 'x' ? 1 : 0) == -1) 569 ret = 1; 570 goto done; 571 } else if (lflag) { 572 if (list_identities(agent_fd, lflag == 'l' ? 1 : 0) == -1) 573 ret = 1; 574 goto done; 575 } else if (Dflag) { 576 if (delete_all(agent_fd) == -1) 577 ret = 1; 578 goto done; 579 } 580 581 argc -= optind; 582 argv += optind; 583 if (pkcs11provider != NULL) { 584 if (update_card(agent_fd, !deleting, pkcs11provider) == -1) 585 ret = 1; 586 goto done; 587 } 588 if (argc == 0) { 589 char buf[PATH_MAX]; 590 struct passwd *pw; 591 struct stat st; 592 int count = 0; 593 594 if ((pw = getpwuid(getuid())) == NULL) { 595 fprintf(stderr, "No user found with uid %u\n", 596 (u_int)getuid()); 597 ret = 1; 598 goto done; 599 } 600 601 for (i = 0; default_files[i]; i++) { 602 snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir, 603 default_files[i]); 604 if (stat(buf, &st) < 0) 605 continue; 606 if (do_file(agent_fd, deleting, key_only, buf) == -1) 607 ret = 1; 608 else 609 count++; 610 } 611 if (count == 0) 612 ret = 1; 613 } else { 614 for (i = 0; i < argc; i++) { 615 if (do_file(agent_fd, deleting, key_only, 616 argv[i]) == -1) 617 ret = 1; 618 } 619 } 620 clear_pass(); 621 622 done: 623 ssh_close_authentication_socket(agent_fd); 624 return ret; 625 } 626