1 /* $OpenBSD: ssh-add.c,v 1.125 2015/09/13 14:39:16 tim 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 passphrase */ 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, "", &private, 214 &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, &private, 222 &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 } 228 if (private == NULL) { 229 /* clear passphrase since it did not work */ 230 clear_pass(); 231 snprintf(msg, sizeof msg, "Enter passphrase for %s%s: ", 232 filename, confirm ? " (will confirm each use)" : ""); 233 for (;;) { 234 pass = read_passphrase(msg, RP_ALLOW_STDIN); 235 if (strcmp(pass, "") == 0) 236 goto fail_load; 237 if ((r = sshkey_parse_private_fileblob(keyblob, pass, 238 &private, &comment)) == 0) 239 break; 240 else if (r != SSH_ERR_KEY_WRONG_PASSPHRASE) { 241 fprintf(stderr, 242 "Error loading key \"%s\": %s\n", 243 filename, ssh_err(r)); 244 fail_load: 245 clear_pass(); 246 sshbuf_free(keyblob); 247 return -1; 248 } 249 clear_pass(); 250 snprintf(msg, sizeof msg, 251 "Bad passphrase, try again for %s%s: ", filename, 252 confirm ? " (will confirm each use)" : ""); 253 } 254 } 255 if (comment == NULL || *comment == '\0') 256 comment = xstrdup(filename); 257 sshbuf_free(keyblob); 258 259 if ((r = ssh_add_identity_constrained(agent_fd, private, comment, 260 lifetime, confirm)) == 0) { 261 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment); 262 ret = 0; 263 if (lifetime != 0) 264 fprintf(stderr, 265 "Lifetime set to %d seconds\n", lifetime); 266 if (confirm != 0) 267 fprintf(stderr, 268 "The user must confirm each use of the key\n"); 269 } else { 270 fprintf(stderr, "Could not add identity \"%s\": %s\n", 271 filename, ssh_err(r)); 272 } 273 274 /* Skip trying to load the cert if requested */ 275 if (key_only) 276 goto out; 277 278 /* Now try to add the certificate flavour too */ 279 xasprintf(&certpath, "%s-cert.pub", filename); 280 if ((r = sshkey_load_public(certpath, &cert, NULL)) != 0) { 281 if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT) 282 error("Failed to load certificate \"%s\": %s", 283 certpath, ssh_err(r)); 284 goto out; 285 } 286 287 if (!sshkey_equal_public(cert, private)) { 288 error("Certificate %s does not match private key %s", 289 certpath, filename); 290 sshkey_free(cert); 291 goto out; 292 } 293 294 /* Graft with private bits */ 295 if ((r = sshkey_to_certified(private)) != 0) { 296 error("%s: sshkey_to_certified: %s", __func__, ssh_err(r)); 297 sshkey_free(cert); 298 goto out; 299 } 300 if ((r = sshkey_cert_copy(cert, private)) != 0) { 301 error("%s: key_cert_copy: %s", __func__, ssh_err(r)); 302 sshkey_free(cert); 303 goto out; 304 } 305 sshkey_free(cert); 306 307 if ((r = ssh_add_identity_constrained(agent_fd, private, comment, 308 lifetime, confirm)) != 0) { 309 error("Certificate %s (%s) add failed: %s", certpath, 310 private->cert->key_id, ssh_err(r)); 311 goto out; 312 } 313 fprintf(stderr, "Certificate added: %s (%s)\n", certpath, 314 private->cert->key_id); 315 if (lifetime != 0) 316 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime); 317 if (confirm != 0) 318 fprintf(stderr, "The user must confirm each use of the key\n"); 319 out: 320 free(certpath); 321 free(comment); 322 sshkey_free(private); 323 324 return ret; 325 } 326 327 static int 328 update_card(int agent_fd, int add, const char *id) 329 { 330 char *pin = NULL; 331 int r, ret = -1; 332 333 if (add) { 334 if ((pin = read_passphrase("Enter passphrase for PKCS#11: ", 335 RP_ALLOW_STDIN)) == NULL) 336 return -1; 337 } 338 339 if ((r = ssh_update_card(agent_fd, add, id, pin == NULL ? "" : pin, 340 lifetime, confirm)) == 0) { 341 fprintf(stderr, "Card %s: %s\n", 342 add ? "added" : "removed", id); 343 ret = 0; 344 } else { 345 fprintf(stderr, "Could not %s card \"%s\": %s\n", 346 add ? "add" : "remove", id, ssh_err(r)); 347 ret = -1; 348 } 349 free(pin); 350 return ret; 351 } 352 353 static int 354 list_identities(int agent_fd, int do_fp) 355 { 356 char *fp; 357 int r, had_identities = 0; 358 struct ssh_identitylist *idlist; 359 size_t i; 360 #ifdef WITH_SSH1 361 int version = 1; 362 #else 363 int version = 2; 364 #endif 365 366 for (; version <= 2; version++) { 367 if ((r = ssh_fetch_identitylist(agent_fd, version, 368 &idlist)) != 0) { 369 if (r != SSH_ERR_AGENT_NO_IDENTITIES) 370 fprintf(stderr, "error fetching identities for " 371 "protocol %d: %s\n", version, ssh_err(r)); 372 continue; 373 } 374 for (i = 0; i < idlist->nkeys; i++) { 375 had_identities = 1; 376 if (do_fp) { 377 fp = sshkey_fingerprint(idlist->keys[i], 378 fingerprint_hash, SSH_FP_DEFAULT); 379 printf("%d %s %s (%s)\n", 380 sshkey_size(idlist->keys[i]), 381 fp == NULL ? "(null)" : fp, 382 idlist->comments[i], 383 sshkey_type(idlist->keys[i])); 384 free(fp); 385 } else { 386 if ((r = sshkey_write(idlist->keys[i], 387 stdout)) != 0) { 388 fprintf(stderr, "sshkey_write: %s\n", 389 ssh_err(r)); 390 continue; 391 } 392 fprintf(stdout, " %s\n", idlist->comments[i]); 393 } 394 } 395 ssh_free_identitylist(idlist); 396 } 397 if (!had_identities) { 398 printf("The agent has no identities.\n"); 399 return -1; 400 } 401 return 0; 402 } 403 404 static int 405 lock_agent(int agent_fd, int lock) 406 { 407 char prompt[100], *p1, *p2; 408 int r, passok = 1, ret = -1; 409 410 strlcpy(prompt, "Enter lock password: ", sizeof(prompt)); 411 p1 = read_passphrase(prompt, RP_ALLOW_STDIN); 412 if (lock) { 413 strlcpy(prompt, "Again: ", sizeof prompt); 414 p2 = read_passphrase(prompt, RP_ALLOW_STDIN); 415 if (strcmp(p1, p2) != 0) { 416 fprintf(stderr, "Passwords do not match.\n"); 417 passok = 0; 418 } 419 explicit_bzero(p2, strlen(p2)); 420 free(p2); 421 } 422 if (passok) { 423 if ((r = ssh_lock_agent(agent_fd, lock, p1)) == 0) { 424 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un"); 425 ret = 0; 426 } else { 427 fprintf(stderr, "Failed to %slock agent: %s\n", 428 lock ? "" : "un", ssh_err(r)); 429 } 430 } 431 explicit_bzero(p1, strlen(p1)); 432 free(p1); 433 return (ret); 434 } 435 436 static int 437 do_file(int agent_fd, int deleting, int key_only, char *file) 438 { 439 if (deleting) { 440 if (delete_file(agent_fd, file, key_only) == -1) 441 return -1; 442 } else { 443 if (add_file(agent_fd, file, key_only) == -1) 444 return -1; 445 } 446 return 0; 447 } 448 449 static void 450 usage(void) 451 { 452 fprintf(stderr, "usage: %s [options] [file ...]\n", __progname); 453 fprintf(stderr, "Options:\n"); 454 fprintf(stderr, " -l List fingerprints of all identities.\n"); 455 fprintf(stderr, " -E hash Specify hash algorithm used for fingerprints.\n"); 456 fprintf(stderr, " -L List public key parameters of all identities.\n"); 457 fprintf(stderr, " -k Load only keys and not certificates.\n"); 458 fprintf(stderr, " -c Require confirmation to sign using identities\n"); 459 fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n"); 460 fprintf(stderr, " -d Delete identity.\n"); 461 fprintf(stderr, " -D Delete all identities.\n"); 462 fprintf(stderr, " -x Lock agent.\n"); 463 fprintf(stderr, " -X Unlock agent.\n"); 464 fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n"); 465 fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n"); 466 } 467 468 int 469 main(int argc, char **argv) 470 { 471 extern char *optarg; 472 extern int optind; 473 int agent_fd; 474 char *pkcs11provider = NULL; 475 int r, i, ch, deleting = 0, ret = 0, key_only = 0; 476 int xflag = 0, lflag = 0, Dflag = 0; 477 478 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 479 sanitise_stdfd(); 480 481 OpenSSL_add_all_algorithms(); 482 483 setvbuf(stdout, NULL, _IOLBF, 0); 484 485 /* First, get a connection to the authentication agent. */ 486 switch (r = ssh_get_authentication_socket(&agent_fd)) { 487 case 0: 488 break; 489 case SSH_ERR_AGENT_NOT_PRESENT: 490 fprintf(stderr, "Could not open a connection to your " 491 "authentication agent.\n"); 492 exit(2); 493 default: 494 fprintf(stderr, "Error connecting to agent: %s\n", ssh_err(r)); 495 exit(2); 496 } 497 498 while ((ch = getopt(argc, argv, "klLcdDxXE:e:s:t:")) != -1) { 499 switch (ch) { 500 case 'E': 501 fingerprint_hash = ssh_digest_alg_by_name(optarg); 502 if (fingerprint_hash == -1) 503 fatal("Invalid hash algorithm \"%s\"", optarg); 504 break; 505 case 'k': 506 key_only = 1; 507 break; 508 case 'l': 509 case 'L': 510 if (lflag != 0) 511 fatal("-%c flag already specified", lflag); 512 lflag = ch; 513 break; 514 case 'x': 515 case 'X': 516 if (xflag != 0) 517 fatal("-%c flag already specified", xflag); 518 xflag = ch; 519 break; 520 case 'c': 521 confirm = 1; 522 break; 523 case 'd': 524 deleting = 1; 525 break; 526 case 'D': 527 Dflag = 1; 528 break; 529 case 's': 530 pkcs11provider = optarg; 531 break; 532 case 'e': 533 deleting = 1; 534 pkcs11provider = optarg; 535 break; 536 case 't': 537 if ((lifetime = convtime(optarg)) == -1) { 538 fprintf(stderr, "Invalid lifetime\n"); 539 ret = 1; 540 goto done; 541 } 542 break; 543 default: 544 usage(); 545 ret = 1; 546 goto done; 547 } 548 } 549 550 if ((xflag != 0) + (lflag != 0) + (Dflag != 0) > 1) 551 fatal("Invalid combination of actions"); 552 else if (xflag) { 553 if (lock_agent(agent_fd, xflag == 'x' ? 1 : 0) == -1) 554 ret = 1; 555 goto done; 556 } else if (lflag) { 557 if (list_identities(agent_fd, lflag == 'l' ? 1 : 0) == -1) 558 ret = 1; 559 goto done; 560 } else if (Dflag) { 561 if (delete_all(agent_fd) == -1) 562 ret = 1; 563 goto done; 564 } 565 566 argc -= optind; 567 argv += optind; 568 if (pkcs11provider != NULL) { 569 if (update_card(agent_fd, !deleting, pkcs11provider) == -1) 570 ret = 1; 571 goto done; 572 } 573 if (argc == 0) { 574 char buf[PATH_MAX]; 575 struct passwd *pw; 576 struct stat st; 577 int count = 0; 578 579 if ((pw = getpwuid(getuid())) == NULL) { 580 fprintf(stderr, "No user found with uid %u\n", 581 (u_int)getuid()); 582 ret = 1; 583 goto done; 584 } 585 586 for (i = 0; default_files[i]; i++) { 587 snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir, 588 default_files[i]); 589 if (stat(buf, &st) < 0) 590 continue; 591 if (do_file(agent_fd, deleting, key_only, buf) == -1) 592 ret = 1; 593 else 594 count++; 595 } 596 if (count == 0) 597 ret = 1; 598 } else { 599 for (i = 0; i < argc; i++) { 600 if (do_file(agent_fd, deleting, key_only, 601 argv[i]) == -1) 602 ret = 1; 603 } 604 } 605 clear_pass(); 606 607 done: 608 ssh_close_authentication_socket(agent_fd); 609 return ret; 610 } 611