1 /* $OpenBSD: ssh-add.c,v 1.128 2016/02/15 09:47:49 dtucker 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 passphrase */ 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 sshkey_free(cert); 154 sshkey_free(public); 155 free(certpath); 156 free(comment); 157 158 return ret; 159 } 160 161 /* Send a request to remove all identities. */ 162 static int 163 delete_all(int agent_fd) 164 { 165 int ret = -1; 166 167 if (ssh_remove_all_identities(agent_fd, 2) == 0) 168 ret = 0; 169 /* ignore error-code for ssh1 */ 170 ssh_remove_all_identities(agent_fd, 1); 171 172 if (ret == 0) 173 fprintf(stderr, "All identities removed.\n"); 174 else 175 fprintf(stderr, "Failed to remove all identities.\n"); 176 177 return ret; 178 } 179 180 static int 181 add_file(int agent_fd, const char *filename, int key_only) 182 { 183 struct sshkey *private, *cert; 184 char *comment = NULL; 185 char msg[1024], *certpath = NULL; 186 int r, fd, ret = -1; 187 struct sshbuf *keyblob; 188 189 if (strcmp(filename, "-") == 0) { 190 fd = STDIN_FILENO; 191 filename = "(stdin)"; 192 } else if ((fd = open(filename, O_RDONLY)) < 0) { 193 perror(filename); 194 return -1; 195 } 196 197 /* 198 * Since we'll try to load a keyfile multiple times, permission errors 199 * will occur multiple times, so check perms first and bail if wrong. 200 */ 201 if (fd != STDIN_FILENO) { 202 if (sshkey_perm_ok(fd, filename) != 0) { 203 close(fd); 204 return -1; 205 } 206 } 207 if ((keyblob = sshbuf_new()) == NULL) 208 fatal("%s: sshbuf_new failed", __func__); 209 if ((r = sshkey_load_file(fd, keyblob)) != 0) { 210 fprintf(stderr, "Error loading key \"%s\": %s\n", 211 filename, ssh_err(r)); 212 sshbuf_free(keyblob); 213 close(fd); 214 return -1; 215 } 216 close(fd); 217 218 /* At first, try empty passphrase */ 219 if ((r = sshkey_parse_private_fileblob(keyblob, "", &private, 220 &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) { 221 fprintf(stderr, "Error loading key \"%s\": %s\n", 222 filename, ssh_err(r)); 223 goto fail_load; 224 } 225 /* try last */ 226 if (private == NULL && pass != NULL) { 227 if ((r = sshkey_parse_private_fileblob(keyblob, pass, &private, 228 &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) { 229 fprintf(stderr, "Error loading key \"%s\": %s\n", 230 filename, ssh_err(r)); 231 goto fail_load; 232 } 233 } 234 if (private == NULL) { 235 /* clear passphrase since it did not work */ 236 clear_pass(); 237 snprintf(msg, sizeof msg, "Enter passphrase for %s%s: ", 238 filename, confirm ? " (will confirm each use)" : ""); 239 for (;;) { 240 pass = read_passphrase(msg, RP_ALLOW_STDIN); 241 if (strcmp(pass, "") == 0) 242 goto fail_load; 243 if ((r = sshkey_parse_private_fileblob(keyblob, pass, 244 &private, &comment)) == 0) 245 break; 246 else if (r != SSH_ERR_KEY_WRONG_PASSPHRASE) { 247 fprintf(stderr, 248 "Error loading key \"%s\": %s\n", 249 filename, ssh_err(r)); 250 fail_load: 251 clear_pass(); 252 sshbuf_free(keyblob); 253 return -1; 254 } 255 clear_pass(); 256 snprintf(msg, sizeof msg, 257 "Bad passphrase, try again for %s%s: ", filename, 258 confirm ? " (will confirm each use)" : ""); 259 } 260 } 261 if (comment == NULL || *comment == '\0') 262 comment = xstrdup(filename); 263 sshbuf_free(keyblob); 264 265 if ((r = ssh_add_identity_constrained(agent_fd, private, comment, 266 lifetime, confirm)) == 0) { 267 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment); 268 ret = 0; 269 if (lifetime != 0) 270 fprintf(stderr, 271 "Lifetime set to %d seconds\n", lifetime); 272 if (confirm != 0) 273 fprintf(stderr, 274 "The user must confirm each use of the key\n"); 275 } else { 276 fprintf(stderr, "Could not add identity \"%s\": %s\n", 277 filename, ssh_err(r)); 278 } 279 280 /* Skip trying to load the cert if requested */ 281 if (key_only) 282 goto out; 283 284 /* Now try to add the certificate flavour too */ 285 xasprintf(&certpath, "%s-cert.pub", filename); 286 if ((r = sshkey_load_public(certpath, &cert, NULL)) != 0) { 287 if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT) 288 error("Failed to load certificate \"%s\": %s", 289 certpath, ssh_err(r)); 290 goto out; 291 } 292 293 if (!sshkey_equal_public(cert, private)) { 294 error("Certificate %s does not match private key %s", 295 certpath, filename); 296 sshkey_free(cert); 297 goto out; 298 } 299 300 /* Graft with private bits */ 301 if ((r = sshkey_to_certified(private)) != 0) { 302 error("%s: sshkey_to_certified: %s", __func__, ssh_err(r)); 303 sshkey_free(cert); 304 goto out; 305 } 306 if ((r = sshkey_cert_copy(cert, private)) != 0) { 307 error("%s: key_cert_copy: %s", __func__, ssh_err(r)); 308 sshkey_free(cert); 309 goto out; 310 } 311 sshkey_free(cert); 312 313 if ((r = ssh_add_identity_constrained(agent_fd, private, comment, 314 lifetime, confirm)) != 0) { 315 error("Certificate %s (%s) add failed: %s", certpath, 316 private->cert->key_id, ssh_err(r)); 317 goto out; 318 } 319 fprintf(stderr, "Certificate added: %s (%s)\n", certpath, 320 private->cert->key_id); 321 if (lifetime != 0) 322 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime); 323 if (confirm != 0) 324 fprintf(stderr, "The user must confirm each use of the key\n"); 325 out: 326 free(certpath); 327 free(comment); 328 sshkey_free(private); 329 330 return ret; 331 } 332 333 static int 334 update_card(int agent_fd, int add, const char *id) 335 { 336 char *pin = NULL; 337 int r, ret = -1; 338 339 if (add) { 340 if ((pin = read_passphrase("Enter passphrase for PKCS#11: ", 341 RP_ALLOW_STDIN)) == NULL) 342 return -1; 343 } 344 345 if ((r = ssh_update_card(agent_fd, add, id, pin == NULL ? "" : pin, 346 lifetime, confirm)) == 0) { 347 fprintf(stderr, "Card %s: %s\n", 348 add ? "added" : "removed", id); 349 ret = 0; 350 } else { 351 fprintf(stderr, "Could not %s card \"%s\": %s\n", 352 add ? "add" : "remove", id, ssh_err(r)); 353 ret = -1; 354 } 355 free(pin); 356 return ret; 357 } 358 359 static int 360 list_identities(int agent_fd, int do_fp) 361 { 362 char *fp; 363 int r, had_identities = 0; 364 struct ssh_identitylist *idlist; 365 size_t i; 366 #ifdef WITH_SSH1 367 int version = 1; 368 #else 369 int version = 2; 370 #endif 371 372 for (; version <= 2; version++) { 373 if ((r = ssh_fetch_identitylist(agent_fd, version, 374 &idlist)) != 0) { 375 if (r != SSH_ERR_AGENT_NO_IDENTITIES) 376 fprintf(stderr, "error fetching identities for " 377 "protocol %d: %s\n", version, ssh_err(r)); 378 continue; 379 } 380 for (i = 0; i < idlist->nkeys; i++) { 381 had_identities = 1; 382 if (do_fp) { 383 fp = sshkey_fingerprint(idlist->keys[i], 384 fingerprint_hash, SSH_FP_DEFAULT); 385 printf("%u %s %s (%s)\n", 386 sshkey_size(idlist->keys[i]), 387 fp == NULL ? "(null)" : fp, 388 idlist->comments[i], 389 sshkey_type(idlist->keys[i])); 390 free(fp); 391 } else { 392 if ((r = sshkey_write(idlist->keys[i], 393 stdout)) != 0) { 394 fprintf(stderr, "sshkey_write: %s\n", 395 ssh_err(r)); 396 continue; 397 } 398 fprintf(stdout, " %s\n", idlist->comments[i]); 399 } 400 } 401 ssh_free_identitylist(idlist); 402 } 403 if (!had_identities) { 404 printf("The agent has no identities.\n"); 405 return -1; 406 } 407 return 0; 408 } 409 410 static int 411 lock_agent(int agent_fd, int lock) 412 { 413 char prompt[100], *p1, *p2; 414 int r, passok = 1, ret = -1; 415 416 strlcpy(prompt, "Enter lock password: ", sizeof(prompt)); 417 p1 = read_passphrase(prompt, RP_ALLOW_STDIN); 418 if (lock) { 419 strlcpy(prompt, "Again: ", sizeof prompt); 420 p2 = read_passphrase(prompt, RP_ALLOW_STDIN); 421 if (strcmp(p1, p2) != 0) { 422 fprintf(stderr, "Passwords do not match.\n"); 423 passok = 0; 424 } 425 explicit_bzero(p2, strlen(p2)); 426 free(p2); 427 } 428 if (passok) { 429 if ((r = ssh_lock_agent(agent_fd, lock, p1)) == 0) { 430 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un"); 431 ret = 0; 432 } else { 433 fprintf(stderr, "Failed to %slock agent: %s\n", 434 lock ? "" : "un", ssh_err(r)); 435 } 436 } 437 explicit_bzero(p1, strlen(p1)); 438 free(p1); 439 return (ret); 440 } 441 442 static int 443 do_file(int agent_fd, int deleting, int key_only, char *file) 444 { 445 if (deleting) { 446 if (delete_file(agent_fd, file, key_only) == -1) 447 return -1; 448 } else { 449 if (add_file(agent_fd, file, key_only) == -1) 450 return -1; 451 } 452 return 0; 453 } 454 455 static void 456 usage(void) 457 { 458 fprintf(stderr, "usage: %s [options] [file ...]\n", __progname); 459 fprintf(stderr, "Options:\n"); 460 fprintf(stderr, " -l List fingerprints of all identities.\n"); 461 fprintf(stderr, " -E hash Specify hash algorithm used for fingerprints.\n"); 462 fprintf(stderr, " -L List public key parameters of all identities.\n"); 463 fprintf(stderr, " -k Load only keys and not certificates.\n"); 464 fprintf(stderr, " -c Require confirmation to sign using identities\n"); 465 fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n"); 466 fprintf(stderr, " -d Delete identity.\n"); 467 fprintf(stderr, " -D Delete all identities.\n"); 468 fprintf(stderr, " -x Lock agent.\n"); 469 fprintf(stderr, " -X Unlock agent.\n"); 470 fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n"); 471 fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n"); 472 } 473 474 int 475 main(int argc, char **argv) 476 { 477 extern char *optarg; 478 extern int optind; 479 int agent_fd; 480 char *pkcs11provider = NULL; 481 int r, i, ch, deleting = 0, ret = 0, key_only = 0; 482 int xflag = 0, lflag = 0, Dflag = 0; 483 484 ssh_malloc_init(); /* must be called before any mallocs */ 485 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 486 sanitise_stdfd(); 487 488 __progname = ssh_get_progname(argv[0]); 489 seed_rng(); 490 491 #ifdef WITH_OPENSSL 492 OpenSSL_add_all_algorithms(); 493 #endif 494 495 setvbuf(stdout, NULL, _IOLBF, 0); 496 497 /* First, get a connection to the authentication agent. */ 498 switch (r = ssh_get_authentication_socket(&agent_fd)) { 499 case 0: 500 break; 501 case SSH_ERR_AGENT_NOT_PRESENT: 502 fprintf(stderr, "Could not open a connection to your " 503 "authentication agent.\n"); 504 exit(2); 505 default: 506 fprintf(stderr, "Error connecting to agent: %s\n", ssh_err(r)); 507 exit(2); 508 } 509 510 while ((ch = getopt(argc, argv, "klLcdDxXE:e:s:t:")) != -1) { 511 switch (ch) { 512 case 'E': 513 fingerprint_hash = ssh_digest_alg_by_name(optarg); 514 if (fingerprint_hash == -1) 515 fatal("Invalid hash algorithm \"%s\"", optarg); 516 break; 517 case 'k': 518 key_only = 1; 519 break; 520 case 'l': 521 case 'L': 522 if (lflag != 0) 523 fatal("-%c flag already specified", lflag); 524 lflag = ch; 525 break; 526 case 'x': 527 case 'X': 528 if (xflag != 0) 529 fatal("-%c flag already specified", xflag); 530 xflag = ch; 531 break; 532 case 'c': 533 confirm = 1; 534 break; 535 case 'd': 536 deleting = 1; 537 break; 538 case 'D': 539 Dflag = 1; 540 break; 541 case 's': 542 pkcs11provider = optarg; 543 break; 544 case 'e': 545 deleting = 1; 546 pkcs11provider = optarg; 547 break; 548 case 't': 549 if ((lifetime = convtime(optarg)) == -1) { 550 fprintf(stderr, "Invalid lifetime\n"); 551 ret = 1; 552 goto done; 553 } 554 break; 555 default: 556 usage(); 557 ret = 1; 558 goto done; 559 } 560 } 561 562 if ((xflag != 0) + (lflag != 0) + (Dflag != 0) > 1) 563 fatal("Invalid combination of actions"); 564 else if (xflag) { 565 if (lock_agent(agent_fd, xflag == 'x' ? 1 : 0) == -1) 566 ret = 1; 567 goto done; 568 } else if (lflag) { 569 if (list_identities(agent_fd, lflag == 'l' ? 1 : 0) == -1) 570 ret = 1; 571 goto done; 572 } else if (Dflag) { 573 if (delete_all(agent_fd) == -1) 574 ret = 1; 575 goto done; 576 } 577 578 argc -= optind; 579 argv += optind; 580 if (pkcs11provider != NULL) { 581 if (update_card(agent_fd, !deleting, pkcs11provider) == -1) 582 ret = 1; 583 goto done; 584 } 585 if (argc == 0) { 586 char buf[PATH_MAX]; 587 struct passwd *pw; 588 struct stat st; 589 int count = 0; 590 591 if ((pw = getpwuid(getuid())) == NULL) { 592 fprintf(stderr, "No user found with uid %u\n", 593 (u_int)getuid()); 594 ret = 1; 595 goto done; 596 } 597 598 for (i = 0; default_files[i]; i++) { 599 snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir, 600 default_files[i]); 601 if (stat(buf, &st) < 0) 602 continue; 603 if (do_file(agent_fd, deleting, key_only, buf) == -1) 604 ret = 1; 605 else 606 count++; 607 } 608 if (count == 0) 609 ret = 1; 610 } else { 611 for (i = 0; i < argc; i++) { 612 if (do_file(agent_fd, deleting, key_only, 613 argv[i]) == -1) 614 ret = 1; 615 } 616 } 617 clear_pass(); 618 619 done: 620 ssh_close_authentication_socket(agent_fd); 621 return ret; 622 } 623