1 /* $OpenBSD: ssh-add.c,v 1.122 2015/03/26 12:32:38 naddy 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 <sys/types.h> 39 #include <sys/stat.h> 40 41 #include <openssl/evp.h> 42 43 #include <errno.h> 44 #include <fcntl.h> 45 #include <pwd.h> 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <unistd.h> 50 #include <limits.h> 51 52 #include "xmalloc.h" 53 #include "ssh.h" 54 #include "rsa.h" 55 #include "log.h" 56 #include "sshkey.h" 57 #include "sshbuf.h" 58 #include "authfd.h" 59 #include "authfile.h" 60 #include "pathnames.h" 61 #include "misc.h" 62 #include "ssherr.h" 63 #include "digest.h" 64 65 /* argv0 */ 66 extern char *__progname; 67 68 /* Default files to add */ 69 static char *default_files[] = { 70 _PATH_SSH_CLIENT_ID_RSA, 71 _PATH_SSH_CLIENT_ID_DSA, 72 _PATH_SSH_CLIENT_ID_ECDSA, 73 _PATH_SSH_CLIENT_ID_ED25519, 74 #ifdef WITH_SSH1 75 _PATH_SSH_CLIENT_IDENTITY, 76 #endif 77 NULL 78 }; 79 80 static int fingerprint_hash = SSH_FP_HASH_DEFAULT; 81 82 /* Default lifetime (0 == forever) */ 83 static int lifetime = 0; 84 85 /* User has to confirm key use */ 86 static int confirm = 0; 87 88 /* we keep a cache of one passphrases */ 89 static char *pass = NULL; 90 static void 91 clear_pass(void) 92 { 93 if (pass) { 94 explicit_bzero(pass, strlen(pass)); 95 free(pass); 96 pass = NULL; 97 } 98 } 99 100 static int 101 delete_file(int agent_fd, const char *filename, int key_only) 102 { 103 struct sshkey *public, *cert = NULL; 104 char *certpath = NULL, *comment = NULL; 105 int r, ret = -1; 106 107 if ((r = sshkey_load_public(filename, &public, &comment)) != 0) { 108 printf("Bad key file %s: %s\n", filename, ssh_err(r)); 109 return -1; 110 } 111 if ((r = ssh_remove_identity(agent_fd, public)) == 0) { 112 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment); 113 ret = 0; 114 } else 115 fprintf(stderr, "Could not remove identity \"%s\": %s\n", 116 filename, ssh_err(r)); 117 118 if (key_only) 119 goto out; 120 121 /* Now try to delete the corresponding certificate too */ 122 free(comment); 123 comment = NULL; 124 xasprintf(&certpath, "%s-cert.pub", filename); 125 if ((r = sshkey_load_public(certpath, &cert, &comment)) != 0) { 126 if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT) 127 error("Failed to load certificate \"%s\": %s", 128 certpath, ssh_err(r)); 129 goto out; 130 } 131 132 if (!sshkey_equal_public(cert, public)) 133 fatal("Certificate %s does not match private key %s", 134 certpath, filename); 135 136 if ((r = ssh_remove_identity(agent_fd, cert)) == 0) { 137 fprintf(stderr, "Identity removed: %s (%s)\n", certpath, 138 comment); 139 ret = 0; 140 } else 141 fprintf(stderr, "Could not remove identity \"%s\": %s\n", 142 certpath, ssh_err(r)); 143 144 out: 145 if (cert != NULL) 146 sshkey_free(cert); 147 if (public != NULL) 148 sshkey_free(public); 149 free(certpath); 150 free(comment); 151 152 return ret; 153 } 154 155 /* Send a request to remove all identities. */ 156 static int 157 delete_all(int agent_fd) 158 { 159 int ret = -1; 160 161 if (ssh_remove_all_identities(agent_fd, 2) == 0) 162 ret = 0; 163 /* ignore error-code for ssh1 */ 164 ssh_remove_all_identities(agent_fd, 1); 165 166 if (ret == 0) 167 fprintf(stderr, "All identities removed.\n"); 168 else 169 fprintf(stderr, "Failed to remove all identities.\n"); 170 171 return ret; 172 } 173 174 static int 175 add_file(int agent_fd, const char *filename, int key_only) 176 { 177 struct sshkey *private, *cert; 178 char *comment = NULL; 179 char msg[1024], *certpath = NULL; 180 int r, fd, ret = -1; 181 struct sshbuf *keyblob; 182 183 if (strcmp(filename, "-") == 0) { 184 fd = STDIN_FILENO; 185 filename = "(stdin)"; 186 } else if ((fd = open(filename, O_RDONLY)) < 0) { 187 perror(filename); 188 return -1; 189 } 190 191 /* 192 * Since we'll try to load a keyfile multiple times, permission errors 193 * will occur multiple times, so check perms first and bail if wrong. 194 */ 195 if (fd != STDIN_FILENO) { 196 if (sshkey_perm_ok(fd, filename) != 0) { 197 close(fd); 198 return -1; 199 } 200 } 201 if ((keyblob = sshbuf_new()) == NULL) 202 fatal("%s: sshbuf_new failed", __func__); 203 if ((r = sshkey_load_file(fd, keyblob)) != 0) { 204 fprintf(stderr, "Error loading key \"%s\": %s\n", 205 filename, ssh_err(r)); 206 sshbuf_free(keyblob); 207 close(fd); 208 return -1; 209 } 210 close(fd); 211 212 /* At first, try empty passphrase */ 213 if ((r = sshkey_parse_private_fileblob(keyblob, "", filename, 214 &private, &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) { 215 fprintf(stderr, "Error loading key \"%s\": %s\n", 216 filename, ssh_err(r)); 217 goto fail_load; 218 } 219 /* try last */ 220 if (private == NULL && pass != NULL) { 221 if ((r = sshkey_parse_private_fileblob(keyblob, pass, filename, 222 &private, &comment)) != 0 && 223 r != SSH_ERR_KEY_WRONG_PASSPHRASE) { 224 fprintf(stderr, "Error loading key \"%s\": %s\n", 225 filename, ssh_err(r)); 226 goto fail_load; 227 } 228 } 229 if (comment == NULL) 230 comment = xstrdup(filename); 231 if (private == NULL) { 232 /* clear passphrase since it did not work */ 233 clear_pass(); 234 snprintf(msg, sizeof msg, "Enter passphrase for %.200s%s: ", 235 comment, confirm ? " (will confirm each use)" : ""); 236 for (;;) { 237 pass = read_passphrase(msg, RP_ALLOW_STDIN); 238 if (strcmp(pass, "") == 0) 239 goto fail_load; 240 if ((r = sshkey_parse_private_fileblob(keyblob, pass, 241 filename, &private, NULL)) == 0) 242 break; 243 else if (r != SSH_ERR_KEY_WRONG_PASSPHRASE) { 244 fprintf(stderr, 245 "Error loading key \"%s\": %s\n", 246 filename, ssh_err(r)); 247 fail_load: 248 clear_pass(); 249 free(comment); 250 sshbuf_free(keyblob); 251 return -1; 252 } 253 clear_pass(); 254 snprintf(msg, sizeof msg, 255 "Bad passphrase, try again for %.200s%s: ", comment, 256 confirm ? " (will confirm each use)" : ""); 257 } 258 } 259 sshbuf_free(keyblob); 260 261 if ((r = ssh_add_identity_constrained(agent_fd, private, comment, 262 lifetime, confirm)) == 0) { 263 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment); 264 ret = 0; 265 if (lifetime != 0) 266 fprintf(stderr, 267 "Lifetime set to %d seconds\n", lifetime); 268 if (confirm != 0) 269 fprintf(stderr, 270 "The user must confirm each use of the key\n"); 271 } else { 272 fprintf(stderr, "Could not add identity \"%s\": %s\n", 273 filename, ssh_err(r)); 274 } 275 276 /* Skip trying to load the cert if requested */ 277 if (key_only) 278 goto out; 279 280 /* Now try to add the certificate flavour too */ 281 xasprintf(&certpath, "%s-cert.pub", filename); 282 if ((r = sshkey_load_public(certpath, &cert, NULL)) != 0) { 283 if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT) 284 error("Failed to load certificate \"%s\": %s", 285 certpath, ssh_err(r)); 286 goto out; 287 } 288 289 if (!sshkey_equal_public(cert, private)) { 290 error("Certificate %s does not match private key %s", 291 certpath, filename); 292 sshkey_free(cert); 293 goto out; 294 } 295 296 /* Graft with private bits */ 297 if ((r = sshkey_to_certified(private, 298 sshkey_cert_is_legacy(cert))) != 0) { 299 error("%s: sshkey_to_certified: %s", __func__, ssh_err(r)); 300 sshkey_free(cert); 301 goto out; 302 } 303 if ((r = sshkey_cert_copy(cert, private)) != 0) { 304 error("%s: key_cert_copy: %s", __func__, ssh_err(r)); 305 sshkey_free(cert); 306 goto out; 307 } 308 sshkey_free(cert); 309 310 if ((r = ssh_add_identity_constrained(agent_fd, private, comment, 311 lifetime, confirm)) != 0) { 312 error("Certificate %s (%s) add failed: %s", certpath, 313 private->cert->key_id, ssh_err(r)); 314 goto out; 315 } 316 fprintf(stderr, "Certificate added: %s (%s)\n", certpath, 317 private->cert->key_id); 318 if (lifetime != 0) 319 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime); 320 if (confirm != 0) 321 fprintf(stderr, "The user must confirm each use of the key\n"); 322 out: 323 free(certpath); 324 free(comment); 325 sshkey_free(private); 326 327 return ret; 328 } 329 330 static int 331 update_card(int agent_fd, int add, const char *id) 332 { 333 char *pin = NULL; 334 int r, ret = -1; 335 336 if (add) { 337 if ((pin = read_passphrase("Enter passphrase for PKCS#11: ", 338 RP_ALLOW_STDIN)) == NULL) 339 return -1; 340 } 341 342 if ((r = ssh_update_card(agent_fd, add, id, pin == NULL ? "" : pin, 343 lifetime, confirm)) == 0) { 344 fprintf(stderr, "Card %s: %s\n", 345 add ? "added" : "removed", id); 346 ret = 0; 347 } else { 348 fprintf(stderr, "Could not %s card \"%s\": %s\n", 349 add ? "add" : "remove", id, ssh_err(r)); 350 ret = -1; 351 } 352 free(pin); 353 return ret; 354 } 355 356 static int 357 list_identities(int agent_fd, int do_fp) 358 { 359 char *fp; 360 int r, had_identities = 0; 361 struct ssh_identitylist *idlist; 362 size_t i; 363 #ifdef WITH_SSH1 364 int version = 1; 365 #else 366 int version = 2; 367 #endif 368 369 for (; version <= 2; version++) { 370 if ((r = ssh_fetch_identitylist(agent_fd, version, 371 &idlist)) != 0) { 372 if (r != SSH_ERR_AGENT_NO_IDENTITIES) 373 fprintf(stderr, "error fetching identities for " 374 "protocol %d: %s\n", version, ssh_err(r)); 375 continue; 376 } 377 for (i = 0; i < idlist->nkeys; i++) { 378 had_identities = 1; 379 if (do_fp) { 380 fp = sshkey_fingerprint(idlist->keys[i], 381 fingerprint_hash, SSH_FP_DEFAULT); 382 printf("%d %s %s (%s)\n", 383 sshkey_size(idlist->keys[i]), 384 fp == NULL ? "(null)" : fp, 385 idlist->comments[i], 386 sshkey_type(idlist->keys[i])); 387 free(fp); 388 } else { 389 if ((r = sshkey_write(idlist->keys[i], 390 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 } 400 if (!had_identities) { 401 printf("The agent has no identities.\n"); 402 return -1; 403 } 404 return 0; 405 } 406 407 static int 408 lock_agent(int agent_fd, int lock) 409 { 410 char prompt[100], *p1, *p2; 411 int r, passok = 1, ret = -1; 412 413 strlcpy(prompt, "Enter lock password: ", sizeof(prompt)); 414 p1 = read_passphrase(prompt, RP_ALLOW_STDIN); 415 if (lock) { 416 strlcpy(prompt, "Again: ", sizeof prompt); 417 p2 = read_passphrase(prompt, RP_ALLOW_STDIN); 418 if (strcmp(p1, p2) != 0) { 419 fprintf(stderr, "Passwords do not match.\n"); 420 passok = 0; 421 } 422 explicit_bzero(p2, strlen(p2)); 423 free(p2); 424 } 425 if (passok) { 426 if ((r = ssh_lock_agent(agent_fd, lock, p1)) == 0) { 427 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un"); 428 ret = 0; 429 } else { 430 fprintf(stderr, "Failed to %slock agent: %s\n", 431 lock ? "" : "un", ssh_err(r)); 432 } 433 } 434 explicit_bzero(p1, strlen(p1)); 435 free(p1); 436 return (ret); 437 } 438 439 static int 440 do_file(int agent_fd, int deleting, int key_only, char *file) 441 { 442 if (deleting) { 443 if (delete_file(agent_fd, file, key_only) == -1) 444 return -1; 445 } else { 446 if (add_file(agent_fd, file, key_only) == -1) 447 return -1; 448 } 449 return 0; 450 } 451 452 static void 453 usage(void) 454 { 455 fprintf(stderr, "usage: %s [options] [file ...]\n", __progname); 456 fprintf(stderr, "Options:\n"); 457 fprintf(stderr, " -l List fingerprints of all identities.\n"); 458 fprintf(stderr, " -E hash Specify hash algorithm used for fingerprints.\n"); 459 fprintf(stderr, " -L List public key parameters of all identities.\n"); 460 fprintf(stderr, " -k Load only keys and not certificates.\n"); 461 fprintf(stderr, " -c Require confirmation to sign using identities\n"); 462 fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n"); 463 fprintf(stderr, " -d Delete identity.\n"); 464 fprintf(stderr, " -D Delete all identities.\n"); 465 fprintf(stderr, " -x Lock agent.\n"); 466 fprintf(stderr, " -X Unlock agent.\n"); 467 fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n"); 468 fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n"); 469 } 470 471 int 472 main(int argc, char **argv) 473 { 474 extern char *optarg; 475 extern int optind; 476 int agent_fd; 477 char *pkcs11provider = NULL; 478 int r, i, ch, deleting = 0, ret = 0, key_only = 0; 479 int xflag = 0, lflag = 0, Dflag = 0; 480 481 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 482 sanitise_stdfd(); 483 484 OpenSSL_add_all_algorithms(); 485 486 setvbuf(stdout, NULL, _IOLBF, 0); 487 488 /* First, get a connection to the authentication agent. */ 489 switch (r = ssh_get_authentication_socket(&agent_fd)) { 490 case 0: 491 break; 492 case SSH_ERR_AGENT_NOT_PRESENT: 493 fprintf(stderr, "Could not open a connection to your " 494 "authentication agent.\n"); 495 exit(2); 496 default: 497 fprintf(stderr, "Error connecting to agent: %s\n", ssh_err(r)); 498 exit(2); 499 } 500 501 while ((ch = getopt(argc, argv, "klLcdDxXE:e:s:t:")) != -1) { 502 switch (ch) { 503 case 'E': 504 fingerprint_hash = ssh_digest_alg_by_name(optarg); 505 if (fingerprint_hash == -1) 506 fatal("Invalid hash algorithm \"%s\"", optarg); 507 break; 508 case 'k': 509 key_only = 1; 510 break; 511 case 'l': 512 case 'L': 513 if (lflag != 0) 514 fatal("-%c flag already specified", lflag); 515 lflag = ch; 516 break; 517 case 'x': 518 case 'X': 519 if (xflag != 0) 520 fatal("-%c flag already specified", xflag); 521 xflag = ch; 522 break; 523 case 'c': 524 confirm = 1; 525 break; 526 case 'd': 527 deleting = 1; 528 break; 529 case 'D': 530 Dflag = 1; 531 break; 532 case 's': 533 pkcs11provider = optarg; 534 break; 535 case 'e': 536 deleting = 1; 537 pkcs11provider = optarg; 538 break; 539 case 't': 540 if ((lifetime = convtime(optarg)) == -1) { 541 fprintf(stderr, "Invalid lifetime\n"); 542 ret = 1; 543 goto done; 544 } 545 break; 546 default: 547 usage(); 548 ret = 1; 549 goto done; 550 } 551 } 552 553 if ((xflag != 0) + (lflag != 0) + (Dflag != 0) > 1) 554 fatal("Invalid combination of actions"); 555 else if (xflag) { 556 if (lock_agent(agent_fd, xflag == 'x' ? 1 : 0) == -1) 557 ret = 1; 558 goto done; 559 } else if (lflag) { 560 if (list_identities(agent_fd, lflag == 'l' ? 1 : 0) == -1) 561 ret = 1; 562 goto done; 563 } else if (Dflag) { 564 if (delete_all(agent_fd) == -1) 565 ret = 1; 566 goto done; 567 } 568 569 argc -= optind; 570 argv += optind; 571 if (pkcs11provider != NULL) { 572 if (update_card(agent_fd, !deleting, pkcs11provider) == -1) 573 ret = 1; 574 goto done; 575 } 576 if (argc == 0) { 577 char buf[PATH_MAX]; 578 struct passwd *pw; 579 struct stat st; 580 int count = 0; 581 582 if ((pw = getpwuid(getuid())) == NULL) { 583 fprintf(stderr, "No user found with uid %u\n", 584 (u_int)getuid()); 585 ret = 1; 586 goto done; 587 } 588 589 for (i = 0; default_files[i]; i++) { 590 snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir, 591 default_files[i]); 592 if (stat(buf, &st) < 0) 593 continue; 594 if (do_file(agent_fd, deleting, key_only, buf) == -1) 595 ret = 1; 596 else 597 count++; 598 } 599 if (count == 0) 600 ret = 1; 601 } else { 602 for (i = 0; i < argc; i++) { 603 if (do_file(agent_fd, deleting, key_only, 604 argv[i]) == -1) 605 ret = 1; 606 } 607 } 608 clear_pass(); 609 610 done: 611 ssh_close_authentication_socket(agent_fd); 612 return ret; 613 } 614