1 /* $NetBSD: ssh-add.c,v 1.10 2015/04/03 23:58:19 christos Exp $ */ 2 /* $OpenBSD: ssh-add.c,v 1.120 2015/02/21 21:46:57 halex Exp $ */ 3 /* 4 * Author: Tatu Ylonen <ylo@cs.hut.fi> 5 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 6 * All rights reserved 7 * Adds an identity to the authentication server, or removes an identity. 8 * 9 * As far as I am concerned, the code I have written for this software 10 * can be used freely for any purpose. Any derived versions of this 11 * software must be clearly marked as such, and if the derived work is 12 * incompatible with the protocol description in the RFC file, it must be 13 * called by a name other than "ssh" or "Secure Shell". 14 * 15 * SSH2 implementation, 16 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions 20 * are met: 21 * 1. Redistributions of source code must retain the above copyright 22 * notice, this list of conditions and the following disclaimer. 23 * 2. Redistributions in binary form must reproduce the above copyright 24 * notice, this list of conditions and the following disclaimer in the 25 * documentation and/or other materials provided with the distribution. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 28 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 29 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 30 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 31 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 32 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 33 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 34 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 35 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 36 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include "includes.h" 40 __RCSID("$NetBSD: ssh-add.c,v 1.10 2015/04/03 23:58:19 christos Exp $"); 41 #include <sys/types.h> 42 #include <sys/stat.h> 43 44 #include <openssl/evp.h> 45 46 #include <errno.h> 47 #include <fcntl.h> 48 #include <pwd.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <unistd.h> 53 #include <limits.h> 54 55 #include "xmalloc.h" 56 #include "ssh.h" 57 #include "rsa.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 const char *default_files[] = { 73 _PATH_SSH_CLIENT_ID_RSA, 74 _PATH_SSH_CLIENT_ID_DSA, 75 _PATH_SSH_CLIENT_ID_ECDSA, 76 _PATH_SSH_CLIENT_ID_ED25519, 77 _PATH_SSH_CLIENT_IDENTITY, 78 NULL 79 }; 80 81 static int fingerprint_hash = SSH_FP_HASH_DEFAULT; 82 83 /* Default lifetime (0 == forever) */ 84 static int lifetime = 0; 85 86 /* User has to confirm key use */ 87 static int confirm = 0; 88 89 /* we keep a cache of one passphrases */ 90 static char *pass = NULL; 91 static void 92 clear_pass(void) 93 { 94 if (pass) { 95 explicit_bzero(pass, strlen(pass)); 96 free(pass); 97 pass = NULL; 98 } 99 } 100 101 static int 102 delete_file(int agent_fd, const char *filename, int key_only) 103 { 104 struct sshkey *public, *cert = NULL; 105 char *certpath = NULL, *comment = NULL; 106 int r, ret = -1; 107 108 if ((r = sshkey_load_public(filename, &public, &comment)) != 0) { 109 printf("Bad key file %s: %s\n", filename, ssh_err(r)); 110 return -1; 111 } 112 if ((r = ssh_remove_identity(agent_fd, public)) == 0) { 113 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment); 114 ret = 0; 115 } else 116 fprintf(stderr, "Could not remove identity \"%s\": %s\n", 117 filename, ssh_err(r)); 118 119 if (key_only) 120 goto out; 121 122 /* Now try to delete the corresponding certificate too */ 123 free(comment); 124 comment = NULL; 125 xasprintf(&certpath, "%s-cert.pub", filename); 126 if ((r = sshkey_load_public(certpath, &cert, &comment)) != 0) { 127 if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT) 128 error("Failed to load certificate \"%s\": %s", 129 certpath, ssh_err(r)); 130 goto out; 131 } 132 133 if (!sshkey_equal_public(cert, public)) 134 fatal("Certificate %s does not match private key %s", 135 certpath, filename); 136 137 if ((r = ssh_remove_identity(agent_fd, cert)) == 0) { 138 fprintf(stderr, "Identity removed: %s (%s)\n", certpath, 139 comment); 140 ret = 0; 141 } else 142 fprintf(stderr, "Could not remove identity \"%s\": %s\n", 143 certpath, ssh_err(r)); 144 145 out: 146 if (cert != NULL) 147 sshkey_free(cert); 148 if (public != NULL) 149 sshkey_free(public); 150 free(certpath); 151 free(comment); 152 153 return ret; 154 } 155 156 /* Send a request to remove all identities. */ 157 static int 158 delete_all(int agent_fd) 159 { 160 int ret = -1; 161 162 if (ssh_remove_all_identities(agent_fd, 1) == 0) 163 ret = 0; 164 /* ignore error-code for ssh2 */ 165 /* XXX revisit */ 166 ssh_remove_all_identities(agent_fd, 2); 167 168 if (ret == 0) 169 fprintf(stderr, "All identities removed.\n"); 170 else 171 fprintf(stderr, "Failed to remove all identities.\n"); 172 173 return ret; 174 } 175 176 static int 177 add_file(int agent_fd, const char *filename, int key_only) 178 { 179 struct sshkey *private, *cert; 180 char *comment = NULL; 181 char msg[1024], *certpath = NULL; 182 int r, fd, ret = -1; 183 struct sshbuf *keyblob; 184 185 if (strcmp(filename, "-") == 0) { 186 fd = STDIN_FILENO; 187 filename = "(stdin)"; 188 } else if ((fd = open(filename, O_RDONLY)) < 0) { 189 perror(filename); 190 return -1; 191 } 192 193 /* 194 * Since we'll try to load a keyfile multiple times, permission errors 195 * will occur multiple times, so check perms first and bail if wrong. 196 */ 197 if (fd != STDIN_FILENO) { 198 if (sshkey_perm_ok(fd, filename) != 0) { 199 close(fd); 200 return -1; 201 } 202 } 203 if ((keyblob = sshbuf_new()) == NULL) 204 fatal("%s: sshbuf_new failed", __func__); 205 if ((r = sshkey_load_file(fd, keyblob)) != 0) { 206 fprintf(stderr, "Error loading key \"%s\": %s\n", 207 filename, ssh_err(r)); 208 sshbuf_free(keyblob); 209 close(fd); 210 return -1; 211 } 212 close(fd); 213 214 /* At first, try empty passphrase */ 215 if ((r = sshkey_parse_private_fileblob(keyblob, "", filename, 216 &private, &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) { 217 fprintf(stderr, "Error loading key \"%s\": %s\n", 218 filename, ssh_err(r)); 219 goto fail_load; 220 } 221 /* try last */ 222 if (private == NULL && pass != NULL) { 223 if ((r = sshkey_parse_private_fileblob(keyblob, pass, filename, 224 &private, &comment)) != 0 && 225 r != SSH_ERR_KEY_WRONG_PASSPHRASE) { 226 fprintf(stderr, "Error loading key \"%s\": %s\n", 227 filename, ssh_err(r)); 228 goto fail_load; 229 } 230 } 231 if (comment == NULL) 232 comment = xstrdup(filename); 233 if (private == NULL) { 234 /* clear passphrase since it did not work */ 235 clear_pass(); 236 snprintf(msg, sizeof msg, "Enter passphrase for %.200s%s: ", 237 comment, confirm ? " (will confirm each use)" : ""); 238 for (;;) { 239 pass = read_passphrase(msg, RP_ALLOW_STDIN); 240 if (strcmp(pass, "") == 0) 241 goto fail_load; 242 if ((r = sshkey_parse_private_fileblob(keyblob, pass, 243 filename, &private, NULL)) == 0) 244 break; 245 else if (r != SSH_ERR_KEY_WRONG_PASSPHRASE) { 246 fprintf(stderr, 247 "Error loading key \"%s\": %s\n", 248 filename, ssh_err(r)); 249 fail_load: 250 clear_pass(); 251 free(comment); 252 sshbuf_free(keyblob); 253 return -1; 254 } 255 clear_pass(); 256 snprintf(msg, sizeof msg, 257 "Bad passphrase, try again for %.200s%s: ", comment, 258 confirm ? " (will confirm each use)" : ""); 259 } 260 } 261 sshbuf_free(keyblob); 262 263 if ((r = ssh_add_identity_constrained(agent_fd, private, comment, 264 lifetime, confirm)) == 0) { 265 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment); 266 ret = 0; 267 if (lifetime != 0) 268 fprintf(stderr, 269 "Lifetime set to %d seconds\n", lifetime); 270 if (confirm != 0) 271 fprintf(stderr, 272 "The user must confirm each use of the key\n"); 273 } else { 274 fprintf(stderr, "Could not add identity \"%s\": %s\n", 275 filename, ssh_err(r)); 276 } 277 278 /* Skip trying to load the cert if requested */ 279 if (key_only) 280 goto out; 281 282 /* Now try to add the certificate flavour too */ 283 xasprintf(&certpath, "%s-cert.pub", filename); 284 if ((r = sshkey_load_public(certpath, &cert, NULL)) != 0) { 285 if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT) 286 error("Failed to load certificate \"%s\": %s", 287 certpath, ssh_err(r)); 288 goto out; 289 } 290 291 if (!sshkey_equal_public(cert, private)) { 292 error("Certificate %s does not match private key %s", 293 certpath, filename); 294 sshkey_free(cert); 295 goto out; 296 } 297 298 /* Graft with private bits */ 299 if ((r = sshkey_to_certified(private, 300 sshkey_cert_is_legacy(cert))) != 0) { 301 error("%s: sshkey_to_certified: %s", __func__, ssh_err(r)); 302 sshkey_free(cert); 303 goto out; 304 } 305 if ((r = sshkey_cert_copy(cert, private)) != 0) { 306 error("%s: key_cert_copy: %s", __func__, ssh_err(r)); 307 sshkey_free(cert); 308 goto out; 309 } 310 sshkey_free(cert); 311 312 if ((r = ssh_add_identity_constrained(agent_fd, private, comment, 313 lifetime, confirm)) != 0) { 314 error("Certificate %s (%s) add failed: %s", certpath, 315 private->cert->key_id, ssh_err(r)); 316 goto out; 317 } 318 fprintf(stderr, "Certificate added: %s (%s)\n", certpath, 319 private->cert->key_id); 320 if (lifetime != 0) 321 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime); 322 if (confirm != 0) 323 fprintf(stderr, "The user must confirm each use of the key\n"); 324 out: 325 free(certpath); 326 free(comment); 327 sshkey_free(private); 328 329 return ret; 330 } 331 332 static int 333 update_card(int agent_fd, int add, const char *id) 334 { 335 char *pin = NULL; 336 int r, ret = -1; 337 338 if (add) { 339 if ((pin = read_passphrase("Enter passphrase for PKCS#11: ", 340 RP_ALLOW_STDIN)) == NULL) 341 return -1; 342 } 343 344 if ((r = ssh_update_card(agent_fd, add, id, pin == NULL ? "" : pin, 345 lifetime, confirm)) == 0) { 346 fprintf(stderr, "Card %s: %s\n", 347 add ? "added" : "removed", id); 348 ret = 0; 349 } else { 350 fprintf(stderr, "Could not %s card \"%s\": %s\n", 351 add ? "add" : "remove", id, ssh_err(r)); 352 ret = -1; 353 } 354 free(pin); 355 return ret; 356 } 357 358 static int 359 list_identities(int agent_fd, int do_fp) 360 { 361 char *fp; 362 int version, r, had_identities = 0; 363 struct ssh_identitylist *idlist; 364 size_t i; 365 366 for (version = 1; 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