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 <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)) != 0) { 298 error("%s: sshkey_to_certified: %s", __func__, ssh_err(r)); 299 sshkey_free(cert); 300 goto out; 301 } 302 if ((r = sshkey_cert_copy(cert, private)) != 0) { 303 error("%s: key_cert_copy: %s", __func__, ssh_err(r)); 304 sshkey_free(cert); 305 goto out; 306 } 307 sshkey_free(cert); 308 309 if ((r = ssh_add_identity_constrained(agent_fd, private, comment, 310 lifetime, confirm)) != 0) { 311 error("Certificate %s (%s) add failed: %s", certpath, 312 private->cert->key_id, ssh_err(r)); 313 goto out; 314 } 315 fprintf(stderr, "Certificate added: %s (%s)\n", certpath, 316 private->cert->key_id); 317 if (lifetime != 0) 318 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime); 319 if (confirm != 0) 320 fprintf(stderr, "The user must confirm each use of the key\n"); 321 out: 322 free(certpath); 323 free(comment); 324 sshkey_free(private); 325 326 return ret; 327 } 328 329 static int 330 update_card(int agent_fd, int add, const char *id) 331 { 332 char *pin = NULL; 333 int r, ret = -1; 334 335 if (add) { 336 if ((pin = read_passphrase("Enter passphrase for PKCS#11: ", 337 RP_ALLOW_STDIN)) == NULL) 338 return -1; 339 } 340 341 if ((r = ssh_update_card(agent_fd, add, id, pin == NULL ? "" : pin, 342 lifetime, confirm)) == 0) { 343 fprintf(stderr, "Card %s: %s\n", 344 add ? "added" : "removed", id); 345 ret = 0; 346 } else { 347 fprintf(stderr, "Could not %s card \"%s\": %s\n", 348 add ? "add" : "remove", id, ssh_err(r)); 349 ret = -1; 350 } 351 free(pin); 352 return ret; 353 } 354 355 static int 356 list_identities(int agent_fd, int do_fp) 357 { 358 char *fp; 359 int r, had_identities = 0; 360 struct ssh_identitylist *idlist; 361 size_t i; 362 #ifdef WITH_SSH1 363 int version = 1; 364 #else 365 int version = 2; 366 #endif 367 368 for (; version <= 2; version++) { 369 if ((r = ssh_fetch_identitylist(agent_fd, version, 370 &idlist)) != 0) { 371 if (r != SSH_ERR_AGENT_NO_IDENTITIES) 372 fprintf(stderr, "error fetching identities for " 373 "protocol %d: %s\n", version, ssh_err(r)); 374 continue; 375 } 376 for (i = 0; i < idlist->nkeys; i++) { 377 had_identities = 1; 378 if (do_fp) { 379 fp = sshkey_fingerprint(idlist->keys[i], 380 fingerprint_hash, SSH_FP_DEFAULT); 381 printf("%d %s %s (%s)\n", 382 sshkey_size(idlist->keys[i]), 383 fp == NULL ? "(null)" : fp, 384 idlist->comments[i], 385 sshkey_type(idlist->keys[i])); 386 free(fp); 387 } else { 388 if ((r = sshkey_write(idlist->keys[i], 389 stdout)) != 0) { 390 fprintf(stderr, "sshkey_write: %s\n", 391 ssh_err(r)); 392 continue; 393 } 394 fprintf(stdout, " %s\n", idlist->comments[i]); 395 } 396 } 397 ssh_free_identitylist(idlist); 398 } 399 if (!had_identities) { 400 printf("The agent has no identities.\n"); 401 return -1; 402 } 403 return 0; 404 } 405 406 static int 407 lock_agent(int agent_fd, int lock) 408 { 409 char prompt[100], *p1, *p2; 410 int r, passok = 1, ret = -1; 411 412 strlcpy(prompt, "Enter lock password: ", sizeof(prompt)); 413 p1 = read_passphrase(prompt, RP_ALLOW_STDIN); 414 if (lock) { 415 strlcpy(prompt, "Again: ", sizeof prompt); 416 p2 = read_passphrase(prompt, RP_ALLOW_STDIN); 417 if (strcmp(p1, p2) != 0) { 418 fprintf(stderr, "Passwords do not match.\n"); 419 passok = 0; 420 } 421 explicit_bzero(p2, strlen(p2)); 422 free(p2); 423 } 424 if (passok) { 425 if ((r = ssh_lock_agent(agent_fd, lock, p1)) == 0) { 426 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un"); 427 ret = 0; 428 } else { 429 fprintf(stderr, "Failed to %slock agent: %s\n", 430 lock ? "" : "un", ssh_err(r)); 431 } 432 } 433 explicit_bzero(p1, strlen(p1)); 434 free(p1); 435 return (ret); 436 } 437 438 static int 439 do_file(int agent_fd, int deleting, int key_only, char *file) 440 { 441 if (deleting) { 442 if (delete_file(agent_fd, file, key_only) == -1) 443 return -1; 444 } else { 445 if (add_file(agent_fd, file, key_only) == -1) 446 return -1; 447 } 448 return 0; 449 } 450 451 static void 452 usage(void) 453 { 454 fprintf(stderr, "usage: %s [options] [file ...]\n", __progname); 455 fprintf(stderr, "Options:\n"); 456 fprintf(stderr, " -l List fingerprints of all identities.\n"); 457 fprintf(stderr, " -E hash Specify hash algorithm used for fingerprints.\n"); 458 fprintf(stderr, " -L List public key parameters of all identities.\n"); 459 fprintf(stderr, " -k Load only keys and not certificates.\n"); 460 fprintf(stderr, " -c Require confirmation to sign using identities\n"); 461 fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n"); 462 fprintf(stderr, " -d Delete identity.\n"); 463 fprintf(stderr, " -D Delete all identities.\n"); 464 fprintf(stderr, " -x Lock agent.\n"); 465 fprintf(stderr, " -X Unlock agent.\n"); 466 fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n"); 467 fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n"); 468 } 469 470 int 471 main(int argc, char **argv) 472 { 473 extern char *optarg; 474 extern int optind; 475 int agent_fd; 476 char *pkcs11provider = NULL; 477 int r, i, ch, deleting = 0, ret = 0, key_only = 0; 478 int xflag = 0, lflag = 0, Dflag = 0; 479 480 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 481 sanitise_stdfd(); 482 483 OpenSSL_add_all_algorithms(); 484 485 setvbuf(stdout, NULL, _IOLBF, 0); 486 487 /* First, get a connection to the authentication agent. */ 488 switch (r = ssh_get_authentication_socket(&agent_fd)) { 489 case 0: 490 break; 491 case SSH_ERR_AGENT_NOT_PRESENT: 492 fprintf(stderr, "Could not open a connection to your " 493 "authentication agent.\n"); 494 exit(2); 495 default: 496 fprintf(stderr, "Error connecting to agent: %s\n", ssh_err(r)); 497 exit(2); 498 } 499 500 while ((ch = getopt(argc, argv, "klLcdDxXE:e:s:t:")) != -1) { 501 switch (ch) { 502 case 'E': 503 fingerprint_hash = ssh_digest_alg_by_name(optarg); 504 if (fingerprint_hash == -1) 505 fatal("Invalid hash algorithm \"%s\"", optarg); 506 break; 507 case 'k': 508 key_only = 1; 509 break; 510 case 'l': 511 case 'L': 512 if (lflag != 0) 513 fatal("-%c flag already specified", lflag); 514 lflag = ch; 515 break; 516 case 'x': 517 case 'X': 518 if (xflag != 0) 519 fatal("-%c flag already specified", xflag); 520 xflag = ch; 521 break; 522 case 'c': 523 confirm = 1; 524 break; 525 case 'd': 526 deleting = 1; 527 break; 528 case 'D': 529 Dflag = 1; 530 break; 531 case 's': 532 pkcs11provider = optarg; 533 break; 534 case 'e': 535 deleting = 1; 536 pkcs11provider = optarg; 537 break; 538 case 't': 539 if ((lifetime = convtime(optarg)) == -1) { 540 fprintf(stderr, "Invalid lifetime\n"); 541 ret = 1; 542 goto done; 543 } 544 break; 545 default: 546 usage(); 547 ret = 1; 548 goto done; 549 } 550 } 551 552 if ((xflag != 0) + (lflag != 0) + (Dflag != 0) > 1) 553 fatal("Invalid combination of actions"); 554 else if (xflag) { 555 if (lock_agent(agent_fd, xflag == 'x' ? 1 : 0) == -1) 556 ret = 1; 557 goto done; 558 } else if (lflag) { 559 if (list_identities(agent_fd, lflag == 'l' ? 1 : 0) == -1) 560 ret = 1; 561 goto done; 562 } else if (Dflag) { 563 if (delete_all(agent_fd) == -1) 564 ret = 1; 565 goto done; 566 } 567 568 argc -= optind; 569 argv += optind; 570 if (pkcs11provider != NULL) { 571 if (update_card(agent_fd, !deleting, pkcs11provider) == -1) 572 ret = 1; 573 goto done; 574 } 575 if (argc == 0) { 576 char buf[PATH_MAX]; 577 struct passwd *pw; 578 struct stat st; 579 int count = 0; 580 581 if ((pw = getpwuid(getuid())) == NULL) { 582 fprintf(stderr, "No user found with uid %u\n", 583 (u_int)getuid()); 584 ret = 1; 585 goto done; 586 } 587 588 for (i = 0; default_files[i]; i++) { 589 snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir, 590 default_files[i]); 591 if (stat(buf, &st) < 0) 592 continue; 593 if (do_file(agent_fd, deleting, key_only, buf) == -1) 594 ret = 1; 595 else 596 count++; 597 } 598 if (count == 0) 599 ret = 1; 600 } else { 601 for (i = 0; i < argc; i++) { 602 if (do_file(agent_fd, deleting, key_only, 603 argv[i]) == -1) 604 ret = 1; 605 } 606 } 607 clear_pass(); 608 609 done: 610 ssh_close_authentication_socket(agent_fd); 611 return ret; 612 } 613