1 /* $OpenBSD: ssh-add.c,v 1.134 2017/08/29 09:42:29 dlg 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 "log.h" 59 #include "sshkey.h" 60 #include "sshbuf.h" 61 #include "authfd.h" 62 #include "authfile.h" 63 #include "pathnames.h" 64 #include "misc.h" 65 #include "ssherr.h" 66 #include "digest.h" 67 68 /* argv0 */ 69 extern char *__progname; 70 71 /* Default files to add */ 72 static char *default_files[] = { 73 #ifdef WITH_OPENSSL 74 _PATH_SSH_CLIENT_ID_RSA, 75 _PATH_SSH_CLIENT_ID_DSA, 76 #ifdef OPENSSL_HAS_ECC 77 _PATH_SSH_CLIENT_ID_ECDSA, 78 #endif 79 #endif /* WITH_OPENSSL */ 80 _PATH_SSH_CLIENT_ID_ED25519, 81 NULL 82 }; 83 84 static int fingerprint_hash = SSH_FP_HASH_DEFAULT; 85 86 /* Default lifetime (0 == forever) */ 87 static int lifetime = 0; 88 89 /* User has to confirm key use */ 90 static int confirm = 0; 91 92 /* we keep a cache of one passphrase */ 93 static char *pass = NULL; 94 static void 95 clear_pass(void) 96 { 97 if (pass) { 98 explicit_bzero(pass, strlen(pass)); 99 free(pass); 100 pass = NULL; 101 } 102 } 103 104 static int 105 delete_file(int agent_fd, const char *filename, int key_only, int qflag) 106 { 107 struct sshkey *public, *cert = NULL; 108 char *certpath = NULL, *comment = NULL; 109 int r, ret = -1; 110 111 if ((r = sshkey_load_public(filename, &public, &comment)) != 0) { 112 printf("Bad key file %s: %s\n", filename, ssh_err(r)); 113 return -1; 114 } 115 if ((r = ssh_remove_identity(agent_fd, public)) == 0) { 116 if (!qflag) { 117 fprintf(stderr, "Identity removed: %s (%s)\n", 118 filename, comment); 119 } 120 ret = 0; 121 } else 122 fprintf(stderr, "Could not remove identity \"%s\": %s\n", 123 filename, ssh_err(r)); 124 125 if (key_only) 126 goto out; 127 128 /* Now try to delete the corresponding certificate too */ 129 free(comment); 130 comment = NULL; 131 xasprintf(&certpath, "%s-cert.pub", filename); 132 if ((r = sshkey_load_public(certpath, &cert, &comment)) != 0) { 133 if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT) 134 error("Failed to load certificate \"%s\": %s", 135 certpath, ssh_err(r)); 136 goto out; 137 } 138 139 if (!sshkey_equal_public(cert, public)) 140 fatal("Certificate %s does not match private key %s", 141 certpath, filename); 142 143 if ((r = ssh_remove_identity(agent_fd, cert)) == 0) { 144 if (!qflag) { 145 fprintf(stderr, "Identity removed: %s (%s)\n", 146 certpath, comment); 147 } 148 ret = 0; 149 } else 150 fprintf(stderr, "Could not remove identity \"%s\": %s\n", 151 certpath, ssh_err(r)); 152 153 out: 154 sshkey_free(cert); 155 sshkey_free(public); 156 free(certpath); 157 free(comment); 158 159 return ret; 160 } 161 162 /* Send a request to remove all identities. */ 163 static int 164 delete_all(int agent_fd) 165 { 166 int ret = -1; 167 168 /* 169 * Since the agent might be forwarded, old or non-OpenSSH, when asked 170 * to remove all keys, attempt to remove both protocol v.1 and v.2 171 * keys. 172 */ 173 if (ssh_remove_all_identities(agent_fd, 2) == 0) 174 ret = 0; 175 /* ignore error-code for ssh1 */ 176 ssh_remove_all_identities(agent_fd, 1); 177 178 if (ret == 0) 179 fprintf(stderr, "All identities removed.\n"); 180 else 181 fprintf(stderr, "Failed to remove all identities.\n"); 182 183 return ret; 184 } 185 186 static int 187 add_file(int agent_fd, const char *filename, int key_only, int qflag) 188 { 189 struct sshkey *private, *cert; 190 char *comment = NULL; 191 char msg[1024], *certpath = NULL; 192 int r, fd, ret = -1; 193 struct sshbuf *keyblob; 194 195 if (strcmp(filename, "-") == 0) { 196 fd = STDIN_FILENO; 197 filename = "(stdin)"; 198 } else if ((fd = open(filename, O_RDONLY)) < 0) { 199 perror(filename); 200 return -1; 201 } 202 203 /* 204 * Since we'll try to load a keyfile multiple times, permission errors 205 * will occur multiple times, so check perms first and bail if wrong. 206 */ 207 if (fd != STDIN_FILENO) { 208 if (sshkey_perm_ok(fd, filename) != 0) { 209 close(fd); 210 return -1; 211 } 212 } 213 if ((keyblob = sshbuf_new()) == NULL) 214 fatal("%s: sshbuf_new failed", __func__); 215 if ((r = sshkey_load_file(fd, keyblob)) != 0) { 216 fprintf(stderr, "Error loading key \"%s\": %s\n", 217 filename, ssh_err(r)); 218 sshbuf_free(keyblob); 219 close(fd); 220 return -1; 221 } 222 close(fd); 223 224 /* At first, try empty passphrase */ 225 if ((r = sshkey_parse_private_fileblob(keyblob, "", &private, 226 &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) { 227 fprintf(stderr, "Error loading key \"%s\": %s\n", 228 filename, ssh_err(r)); 229 goto fail_load; 230 } 231 /* try last */ 232 if (private == NULL && pass != NULL) { 233 if ((r = sshkey_parse_private_fileblob(keyblob, pass, &private, 234 &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) { 235 fprintf(stderr, "Error loading key \"%s\": %s\n", 236 filename, ssh_err(r)); 237 goto fail_load; 238 } 239 } 240 if (private == NULL) { 241 /* clear passphrase since it did not work */ 242 clear_pass(); 243 snprintf(msg, sizeof msg, "Enter passphrase for %s%s: ", 244 filename, confirm ? " (will confirm each use)" : ""); 245 for (;;) { 246 pass = read_passphrase(msg, RP_ALLOW_STDIN); 247 if (strcmp(pass, "") == 0) 248 goto fail_load; 249 if ((r = sshkey_parse_private_fileblob(keyblob, pass, 250 &private, &comment)) == 0) 251 break; 252 else if (r != SSH_ERR_KEY_WRONG_PASSPHRASE) { 253 fprintf(stderr, 254 "Error loading key \"%s\": %s\n", 255 filename, ssh_err(r)); 256 fail_load: 257 clear_pass(); 258 sshbuf_free(keyblob); 259 return -1; 260 } 261 clear_pass(); 262 snprintf(msg, sizeof msg, 263 "Bad passphrase, try again for %s%s: ", filename, 264 confirm ? " (will confirm each use)" : ""); 265 } 266 } 267 if (comment == NULL || *comment == '\0') 268 comment = xstrdup(filename); 269 sshbuf_free(keyblob); 270 271 if ((r = ssh_add_identity_constrained(agent_fd, private, comment, 272 lifetime, confirm)) == 0) { 273 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment); 274 ret = 0; 275 if (lifetime != 0) 276 fprintf(stderr, 277 "Lifetime set to %d seconds\n", lifetime); 278 if (confirm != 0) 279 fprintf(stderr, 280 "The user must confirm each use of the key\n"); 281 } else { 282 fprintf(stderr, "Could not add identity \"%s\": %s\n", 283 filename, ssh_err(r)); 284 } 285 286 /* Skip trying to load the cert if requested */ 287 if (key_only) 288 goto out; 289 290 /* Now try to add the certificate flavour too */ 291 xasprintf(&certpath, "%s-cert.pub", filename); 292 if ((r = sshkey_load_public(certpath, &cert, NULL)) != 0) { 293 if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT) 294 error("Failed to load certificate \"%s\": %s", 295 certpath, ssh_err(r)); 296 goto out; 297 } 298 299 if (!sshkey_equal_public(cert, private)) { 300 error("Certificate %s does not match private key %s", 301 certpath, filename); 302 sshkey_free(cert); 303 goto out; 304 } 305 306 /* Graft with private bits */ 307 if ((r = sshkey_to_certified(private)) != 0) { 308 error("%s: sshkey_to_certified: %s", __func__, ssh_err(r)); 309 sshkey_free(cert); 310 goto out; 311 } 312 if ((r = sshkey_cert_copy(cert, private)) != 0) { 313 error("%s: sshkey_cert_copy: %s", __func__, ssh_err(r)); 314 sshkey_free(cert); 315 goto out; 316 } 317 sshkey_free(cert); 318 319 if ((r = ssh_add_identity_constrained(agent_fd, private, comment, 320 lifetime, confirm)) != 0) { 321 error("Certificate %s (%s) add failed: %s", certpath, 322 private->cert->key_id, ssh_err(r)); 323 goto out; 324 } 325 fprintf(stderr, "Certificate added: %s (%s)\n", certpath, 326 private->cert->key_id); 327 if (lifetime != 0) 328 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime); 329 if (confirm != 0) 330 fprintf(stderr, "The user must confirm each use of the key\n"); 331 out: 332 free(certpath); 333 free(comment); 334 sshkey_free(private); 335 336 return ret; 337 } 338 339 static int 340 update_card(int agent_fd, int add, const char *id) 341 { 342 char *pin = NULL; 343 int r, ret = -1; 344 345 if (add) { 346 if ((pin = read_passphrase("Enter passphrase for PKCS#11: ", 347 RP_ALLOW_STDIN)) == NULL) 348 return -1; 349 } 350 351 if ((r = ssh_update_card(agent_fd, add, id, pin == NULL ? "" : pin, 352 lifetime, confirm)) == 0) { 353 fprintf(stderr, "Card %s: %s\n", 354 add ? "added" : "removed", id); 355 ret = 0; 356 } else { 357 fprintf(stderr, "Could not %s card \"%s\": %s\n", 358 add ? "add" : "remove", id, ssh_err(r)); 359 ret = -1; 360 } 361 free(pin); 362 return ret; 363 } 364 365 static int 366 list_identities(int agent_fd, int do_fp) 367 { 368 char *fp; 369 int r; 370 struct ssh_identitylist *idlist; 371 size_t i; 372 373 if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) { 374 if (r != SSH_ERR_AGENT_NO_IDENTITIES) 375 fprintf(stderr, "error fetching identities: %s\n", 376 ssh_err(r)); 377 else 378 printf("The agent has no identities.\n"); 379 return -1; 380 } 381 for (i = 0; i < idlist->nkeys; i++) { 382 if (do_fp) { 383 fp = sshkey_fingerprint(idlist->keys[i], 384 fingerprint_hash, SSH_FP_DEFAULT); 385 printf("%u %s %s (%s)\n", sshkey_size(idlist->keys[i]), 386 fp == NULL ? "(null)" : fp, idlist->comments[i], 387 sshkey_type(idlist->keys[i])); 388 free(fp); 389 } else { 390 if ((r = sshkey_write(idlist->keys[i], stdout)) != 0) { 391 fprintf(stderr, "sshkey_write: %s\n", 392 ssh_err(r)); 393 continue; 394 } 395 fprintf(stdout, " %s\n", idlist->comments[i]); 396 } 397 } 398 ssh_free_identitylist(idlist); 399 return 0; 400 } 401 402 static int 403 lock_agent(int agent_fd, int lock) 404 { 405 char prompt[100], *p1, *p2; 406 int r, passok = 1, ret = -1; 407 408 strlcpy(prompt, "Enter lock password: ", sizeof(prompt)); 409 p1 = read_passphrase(prompt, RP_ALLOW_STDIN); 410 if (lock) { 411 strlcpy(prompt, "Again: ", sizeof prompt); 412 p2 = read_passphrase(prompt, RP_ALLOW_STDIN); 413 if (strcmp(p1, p2) != 0) { 414 fprintf(stderr, "Passwords do not match.\n"); 415 passok = 0; 416 } 417 explicit_bzero(p2, strlen(p2)); 418 free(p2); 419 } 420 if (passok) { 421 if ((r = ssh_lock_agent(agent_fd, lock, p1)) == 0) { 422 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un"); 423 ret = 0; 424 } else { 425 fprintf(stderr, "Failed to %slock agent: %s\n", 426 lock ? "" : "un", ssh_err(r)); 427 } 428 } 429 explicit_bzero(p1, strlen(p1)); 430 free(p1); 431 return (ret); 432 } 433 434 static int 435 do_file(int agent_fd, int deleting, int key_only, char *file, int qflag) 436 { 437 if (deleting) { 438 if (delete_file(agent_fd, file, key_only, qflag) == -1) 439 return -1; 440 } else { 441 if (add_file(agent_fd, file, key_only, qflag) == -1) 442 return -1; 443 } 444 return 0; 445 } 446 447 static void 448 usage(void) 449 { 450 fprintf(stderr, "usage: %s [options] [file ...]\n", __progname); 451 fprintf(stderr, "Options:\n"); 452 fprintf(stderr, " -l List fingerprints of all identities.\n"); 453 fprintf(stderr, " -E hash Specify hash algorithm used for fingerprints.\n"); 454 fprintf(stderr, " -L List public key parameters of all identities.\n"); 455 fprintf(stderr, " -k Load only keys and not certificates.\n"); 456 fprintf(stderr, " -c Require confirmation to sign using identities\n"); 457 fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n"); 458 fprintf(stderr, " -d Delete identity.\n"); 459 fprintf(stderr, " -D Delete all identities.\n"); 460 fprintf(stderr, " -x Lock agent.\n"); 461 fprintf(stderr, " -X Unlock agent.\n"); 462 fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n"); 463 fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n"); 464 fprintf(stderr, " -q Be quiet after a successful operation.\n"); 465 } 466 467 int 468 main(int argc, char **argv) 469 { 470 extern char *optarg; 471 extern int optind; 472 int agent_fd; 473 char *pkcs11provider = NULL; 474 int r, i, ch, deleting = 0, ret = 0, key_only = 0; 475 int xflag = 0, lflag = 0, Dflag = 0, qflag = 0; 476 477 ssh_malloc_init(); /* must be called before any mallocs */ 478 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 479 sanitise_stdfd(); 480 481 __progname = ssh_get_progname(argv[0]); 482 seed_rng(); 483 484 #ifdef WITH_OPENSSL 485 OpenSSL_add_all_algorithms(); 486 #endif 487 488 setvbuf(stdout, NULL, _IOLBF, 0); 489 490 /* First, get a connection to the authentication agent. */ 491 switch (r = ssh_get_authentication_socket(&agent_fd)) { 492 case 0: 493 break; 494 case SSH_ERR_AGENT_NOT_PRESENT: 495 fprintf(stderr, "Could not open a connection to your " 496 "authentication agent.\n"); 497 exit(2); 498 default: 499 fprintf(stderr, "Error connecting to agent: %s\n", ssh_err(r)); 500 exit(2); 501 } 502 503 while ((ch = getopt(argc, argv, "klLcdDxXE:e:qs:t:")) != -1) { 504 switch (ch) { 505 case 'E': 506 fingerprint_hash = ssh_digest_alg_by_name(optarg); 507 if (fingerprint_hash == -1) 508 fatal("Invalid hash algorithm \"%s\"", optarg); 509 break; 510 case 'k': 511 key_only = 1; 512 break; 513 case 'l': 514 case 'L': 515 if (lflag != 0) 516 fatal("-%c flag already specified", lflag); 517 lflag = ch; 518 break; 519 case 'x': 520 case 'X': 521 if (xflag != 0) 522 fatal("-%c flag already specified", xflag); 523 xflag = ch; 524 break; 525 case 'c': 526 confirm = 1; 527 break; 528 case 'd': 529 deleting = 1; 530 break; 531 case 'D': 532 Dflag = 1; 533 break; 534 case 's': 535 pkcs11provider = optarg; 536 break; 537 case 'e': 538 deleting = 1; 539 pkcs11provider = optarg; 540 break; 541 case 't': 542 if ((lifetime = convtime(optarg)) == -1) { 543 fprintf(stderr, "Invalid lifetime\n"); 544 ret = 1; 545 goto done; 546 } 547 break; 548 case 'q': 549 qflag = 1; 550 break; 551 default: 552 usage(); 553 ret = 1; 554 goto done; 555 } 556 } 557 558 if ((xflag != 0) + (lflag != 0) + (Dflag != 0) > 1) 559 fatal("Invalid combination of actions"); 560 else if (xflag) { 561 if (lock_agent(agent_fd, xflag == 'x' ? 1 : 0) == -1) 562 ret = 1; 563 goto done; 564 } else if (lflag) { 565 if (list_identities(agent_fd, lflag == 'l' ? 1 : 0) == -1) 566 ret = 1; 567 goto done; 568 } else if (Dflag) { 569 if (delete_all(agent_fd) == -1) 570 ret = 1; 571 goto done; 572 } 573 574 argc -= optind; 575 argv += optind; 576 if (pkcs11provider != NULL) { 577 if (update_card(agent_fd, !deleting, pkcs11provider) == -1) 578 ret = 1; 579 goto done; 580 } 581 if (argc == 0) { 582 char buf[PATH_MAX]; 583 struct passwd *pw; 584 struct stat st; 585 int count = 0; 586 587 if ((pw = getpwuid(getuid())) == NULL) { 588 fprintf(stderr, "No user found with uid %u\n", 589 (u_int)getuid()); 590 ret = 1; 591 goto done; 592 } 593 594 for (i = 0; default_files[i]; i++) { 595 snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir, 596 default_files[i]); 597 if (stat(buf, &st) < 0) 598 continue; 599 if (do_file(agent_fd, deleting, key_only, buf, 600 qflag) == -1) 601 ret = 1; 602 else 603 count++; 604 } 605 if (count == 0) 606 ret = 1; 607 } else { 608 for (i = 0; i < argc; i++) { 609 if (do_file(agent_fd, deleting, key_only, 610 argv[i], qflag) == -1) 611 ret = 1; 612 } 613 } 614 clear_pass(); 615 616 done: 617 ssh_close_authentication_socket(agent_fd); 618 return ret; 619 } 620