1 /* $NetBSD: ssh-add.c,v 1.12 2015/08/13 10:33:21 christos Exp $ */ 2 /* $OpenBSD: ssh-add.c,v 1.123 2015/07/03 03:43:18 djm 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 1.12 2015/08/13 10:33:21 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 #ifdef WITH_SSH1 78 _PATH_SSH_CLIENT_IDENTITY, 79 #endif 80 NULL 81 }; 82 83 static int fingerprint_hash = SSH_FP_HASH_DEFAULT; 84 85 /* Default lifetime (0 == forever) */ 86 static int lifetime = 0; 87 88 /* User has to confirm key use */ 89 static int confirm = 0; 90 91 /* we keep a cache of one passphrases */ 92 static char *pass = NULL; 93 static void 94 clear_pass(void) 95 { 96 if (pass) { 97 explicit_bzero(pass, strlen(pass)); 98 free(pass); 99 pass = NULL; 100 } 101 } 102 103 static int 104 delete_file(int agent_fd, const char *filename, int key_only) 105 { 106 struct sshkey *public, *cert = NULL; 107 char *certpath = NULL, *comment = NULL; 108 int r, ret = -1; 109 110 if ((r = sshkey_load_public(filename, &public, &comment)) != 0) { 111 printf("Bad key file %s: %s\n", filename, ssh_err(r)); 112 return -1; 113 } 114 if ((r = ssh_remove_identity(agent_fd, public)) == 0) { 115 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment); 116 ret = 0; 117 } else 118 fprintf(stderr, "Could not remove identity \"%s\": %s\n", 119 filename, ssh_err(r)); 120 121 if (key_only) 122 goto out; 123 124 /* Now try to delete the corresponding certificate too */ 125 free(comment); 126 comment = NULL; 127 xasprintf(&certpath, "%s-cert.pub", filename); 128 if ((r = sshkey_load_public(certpath, &cert, &comment)) != 0) { 129 if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT) 130 error("Failed to load certificate \"%s\": %s", 131 certpath, ssh_err(r)); 132 goto out; 133 } 134 135 if (!sshkey_equal_public(cert, public)) 136 fatal("Certificate %s does not match private key %s", 137 certpath, filename); 138 139 if ((r = ssh_remove_identity(agent_fd, cert)) == 0) { 140 fprintf(stderr, "Identity removed: %s (%s)\n", certpath, 141 comment); 142 ret = 0; 143 } else 144 fprintf(stderr, "Could not remove identity \"%s\": %s\n", 145 certpath, ssh_err(r)); 146 147 out: 148 if (cert != NULL) 149 sshkey_free(cert); 150 if (public != NULL) 151 sshkey_free(public); 152 free(certpath); 153 free(comment); 154 155 return ret; 156 } 157 158 /* Send a request to remove all identities. */ 159 static int 160 delete_all(int agent_fd) 161 { 162 int ret = -1; 163 164 if (ssh_remove_all_identities(agent_fd, 2) == 0) 165 ret = 0; 166 /* ignore error-code for ssh1 */ 167 ssh_remove_all_identities(agent_fd, 1); 168 169 if (ret == 0) 170 fprintf(stderr, "All identities removed.\n"); 171 else 172 fprintf(stderr, "Failed to remove all identities.\n"); 173 174 return ret; 175 } 176 177 static int 178 add_file(int agent_fd, const char *filename, int key_only) 179 { 180 struct sshkey *private, *cert; 181 char *comment = NULL; 182 char msg[1024], *certpath = NULL; 183 int r, fd, ret = -1; 184 struct sshbuf *keyblob; 185 186 if (strcmp(filename, "-") == 0) { 187 fd = STDIN_FILENO; 188 filename = "(stdin)"; 189 } else if ((fd = open(filename, O_RDONLY)) < 0) { 190 perror(filename); 191 return -1; 192 } 193 194 /* 195 * Since we'll try to load a keyfile multiple times, permission errors 196 * will occur multiple times, so check perms first and bail if wrong. 197 */ 198 if (fd != STDIN_FILENO) { 199 if (sshkey_perm_ok(fd, filename) != 0) { 200 close(fd); 201 return -1; 202 } 203 } 204 if ((keyblob = sshbuf_new()) == NULL) 205 fatal("%s: sshbuf_new failed", __func__); 206 if ((r = sshkey_load_file(fd, keyblob)) != 0) { 207 fprintf(stderr, "Error loading key \"%s\": %s\n", 208 filename, ssh_err(r)); 209 sshbuf_free(keyblob); 210 close(fd); 211 return -1; 212 } 213 close(fd); 214 215 /* At first, try empty passphrase */ 216 if ((r = sshkey_parse_private_fileblob(keyblob, "", filename, 217 &private, &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) { 218 fprintf(stderr, "Error loading key \"%s\": %s\n", 219 filename, ssh_err(r)); 220 goto fail_load; 221 } 222 /* try last */ 223 if (private == NULL && pass != NULL) { 224 if ((r = sshkey_parse_private_fileblob(keyblob, pass, filename, 225 &private, &comment)) != 0 && 226 r != SSH_ERR_KEY_WRONG_PASSPHRASE) { 227 fprintf(stderr, "Error loading key \"%s\": %s\n", 228 filename, ssh_err(r)); 229 goto fail_load; 230 } 231 } 232 if (comment == NULL) 233 comment = xstrdup(filename); 234 if (private == NULL) { 235 /* clear passphrase since it did not work */ 236 clear_pass(); 237 snprintf(msg, sizeof msg, "Enter passphrase for %.200s%s: ", 238 comment, 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 filename, &private, NULL)) == 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 free(comment); 253 sshbuf_free(keyblob); 254 return -1; 255 } 256 clear_pass(); 257 snprintf(msg, sizeof msg, 258 "Bad passphrase, try again for %.200s%s: ", comment, 259 confirm ? " (will confirm each use)" : ""); 260 } 261 } 262 sshbuf_free(keyblob); 263 264 if ((r = ssh_add_identity_constrained(agent_fd, private, comment, 265 lifetime, confirm)) == 0) { 266 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment); 267 ret = 0; 268 if (lifetime != 0) 269 fprintf(stderr, 270 "Lifetime set to %d seconds\n", lifetime); 271 if (confirm != 0) 272 fprintf(stderr, 273 "The user must confirm each use of the key\n"); 274 } else { 275 fprintf(stderr, "Could not add identity \"%s\": %s\n", 276 filename, ssh_err(r)); 277 } 278 279 /* Skip trying to load the cert if requested */ 280 if (key_only) 281 goto out; 282 283 /* Now try to add the certificate flavour too */ 284 xasprintf(&certpath, "%s-cert.pub", filename); 285 if ((r = sshkey_load_public(certpath, &cert, NULL)) != 0) { 286 if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT) 287 error("Failed to load certificate \"%s\": %s", 288 certpath, ssh_err(r)); 289 goto out; 290 } 291 292 if (!sshkey_equal_public(cert, private)) { 293 error("Certificate %s does not match private key %s", 294 certpath, filename); 295 sshkey_free(cert); 296 goto out; 297 } 298 299 /* Graft with private bits */ 300 if ((r = sshkey_to_certified(private)) != 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 r, had_identities = 0; 363 struct ssh_identitylist *idlist; 364 size_t i; 365 #ifdef WITH_SSH1 366 int version = 1; 367 #else 368 int version = 2; 369 #endif 370 371 for (; version <= 2; version++) { 372 if ((r = ssh_fetch_identitylist(agent_fd, version, 373 &idlist)) != 0) { 374 if (r != SSH_ERR_AGENT_NO_IDENTITIES) 375 fprintf(stderr, "error fetching identities for " 376 "protocol %d: %s\n", version, ssh_err(r)); 377 continue; 378 } 379 for (i = 0; i < idlist->nkeys; i++) { 380 had_identities = 1; 381 if (do_fp) { 382 fp = sshkey_fingerprint(idlist->keys[i], 383 fingerprint_hash, SSH_FP_DEFAULT); 384 printf("%d %s %s (%s)\n", 385 sshkey_size(idlist->keys[i]), 386 fp == NULL ? "(null)" : fp, 387 idlist->comments[i], 388 sshkey_type(idlist->keys[i])); 389 free(fp); 390 } else { 391 if ((r = sshkey_write(idlist->keys[i], 392 stdout)) != 0) { 393 fprintf(stderr, "sshkey_write: %s\n", 394 ssh_err(r)); 395 continue; 396 } 397 fprintf(stdout, " %s\n", idlist->comments[i]); 398 } 399 } 400 ssh_free_identitylist(idlist); 401 } 402 if (!had_identities) { 403 printf("The agent has no identities.\n"); 404 return -1; 405 } 406 return 0; 407 } 408 409 static int 410 lock_agent(int agent_fd, int lock) 411 { 412 char prompt[100], *p1, *p2; 413 int r, passok = 1, ret = -1; 414 415 strlcpy(prompt, "Enter lock password: ", sizeof(prompt)); 416 p1 = read_passphrase(prompt, RP_ALLOW_STDIN); 417 if (lock) { 418 strlcpy(prompt, "Again: ", sizeof prompt); 419 p2 = read_passphrase(prompt, RP_ALLOW_STDIN); 420 if (strcmp(p1, p2) != 0) { 421 fprintf(stderr, "Passwords do not match.\n"); 422 passok = 0; 423 } 424 explicit_bzero(p2, strlen(p2)); 425 free(p2); 426 } 427 if (passok) { 428 if ((r = ssh_lock_agent(agent_fd, lock, p1)) == 0) { 429 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un"); 430 ret = 0; 431 } else { 432 fprintf(stderr, "Failed to %slock agent: %s\n", 433 lock ? "" : "un", ssh_err(r)); 434 } 435 } 436 explicit_bzero(p1, strlen(p1)); 437 free(p1); 438 return (ret); 439 } 440 441 static int 442 do_file(int agent_fd, int deleting, int key_only, char *file) 443 { 444 if (deleting) { 445 if (delete_file(agent_fd, file, key_only) == -1) 446 return -1; 447 } else { 448 if (add_file(agent_fd, file, key_only) == -1) 449 return -1; 450 } 451 return 0; 452 } 453 454 static void 455 usage(void) 456 { 457 fprintf(stderr, "usage: %s [options] [file ...]\n", __progname); 458 fprintf(stderr, "Options:\n"); 459 fprintf(stderr, " -l List fingerprints of all identities.\n"); 460 fprintf(stderr, " -E hash Specify hash algorithm used for fingerprints.\n"); 461 fprintf(stderr, " -L List public key parameters of all identities.\n"); 462 fprintf(stderr, " -k Load only keys and not certificates.\n"); 463 fprintf(stderr, " -c Require confirmation to sign using identities\n"); 464 fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n"); 465 fprintf(stderr, " -d Delete identity.\n"); 466 fprintf(stderr, " -D Delete all identities.\n"); 467 fprintf(stderr, " -x Lock agent.\n"); 468 fprintf(stderr, " -X Unlock agent.\n"); 469 fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n"); 470 fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n"); 471 } 472 473 int 474 main(int argc, char **argv) 475 { 476 extern char *optarg; 477 extern int optind; 478 int agent_fd; 479 char *pkcs11provider = NULL; 480 int r, i, ch, deleting = 0, ret = 0, key_only = 0; 481 int xflag = 0, lflag = 0, Dflag = 0; 482 483 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 484 sanitise_stdfd(); 485 486 OpenSSL_add_all_algorithms(); 487 488 setvbuf(stdout, NULL, _IOLBF, 0); 489 490 /* First, get a connection to the authentication agent. */ 491 switch (r = ssh_get_authentication_socket(&agent_fd)) { 492 case 0: 493 break; 494 case SSH_ERR_AGENT_NOT_PRESENT: 495 fprintf(stderr, "Could not open a connection to your " 496 "authentication agent.\n"); 497 exit(2); 498 default: 499 fprintf(stderr, "Error connecting to agent: %s\n", ssh_err(r)); 500 exit(2); 501 } 502 503 while ((ch = getopt(argc, argv, "klLcdDxXE:e:s:t:")) != -1) { 504 switch (ch) { 505 case 'E': 506 fingerprint_hash = ssh_digest_alg_by_name(optarg); 507 if (fingerprint_hash == -1) 508 fatal("Invalid hash algorithm \"%s\"", optarg); 509 break; 510 case 'k': 511 key_only = 1; 512 break; 513 case 'l': 514 case 'L': 515 if (lflag != 0) 516 fatal("-%c flag already specified", lflag); 517 lflag = ch; 518 break; 519 case 'x': 520 case 'X': 521 if (xflag != 0) 522 fatal("-%c flag already specified", xflag); 523 xflag = ch; 524 break; 525 case 'c': 526 confirm = 1; 527 break; 528 case 'd': 529 deleting = 1; 530 break; 531 case 'D': 532 Dflag = 1; 533 break; 534 case 's': 535 pkcs11provider = optarg; 536 break; 537 case 'e': 538 deleting = 1; 539 pkcs11provider = optarg; 540 break; 541 case 't': 542 if ((lifetime = convtime(optarg)) == -1) { 543 fprintf(stderr, "Invalid lifetime\n"); 544 ret = 1; 545 goto done; 546 } 547 break; 548 default: 549 usage(); 550 ret = 1; 551 goto done; 552 } 553 } 554 555 if ((xflag != 0) + (lflag != 0) + (Dflag != 0) > 1) 556 fatal("Invalid combination of actions"); 557 else if (xflag) { 558 if (lock_agent(agent_fd, xflag == 'x' ? 1 : 0) == -1) 559 ret = 1; 560 goto done; 561 } else if (lflag) { 562 if (list_identities(agent_fd, lflag == 'l' ? 1 : 0) == -1) 563 ret = 1; 564 goto done; 565 } else if (Dflag) { 566 if (delete_all(agent_fd) == -1) 567 ret = 1; 568 goto done; 569 } 570 571 argc -= optind; 572 argv += optind; 573 if (pkcs11provider != NULL) { 574 if (update_card(agent_fd, !deleting, pkcs11provider) == -1) 575 ret = 1; 576 goto done; 577 } 578 if (argc == 0) { 579 char buf[PATH_MAX]; 580 struct passwd *pw; 581 struct stat st; 582 int count = 0; 583 584 if ((pw = getpwuid(getuid())) == NULL) { 585 fprintf(stderr, "No user found with uid %u\n", 586 (u_int)getuid()); 587 ret = 1; 588 goto done; 589 } 590 591 for (i = 0; default_files[i]; i++) { 592 snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir, 593 default_files[i]); 594 if (stat(buf, &st) < 0) 595 continue; 596 if (do_file(agent_fd, deleting, key_only, buf) == -1) 597 ret = 1; 598 else 599 count++; 600 } 601 if (count == 0) 602 ret = 1; 603 } else { 604 for (i = 0; i < argc; i++) { 605 if (do_file(agent_fd, deleting, key_only, 606 argv[i]) == -1) 607 ret = 1; 608 } 609 } 610 clear_pass(); 611 612 done: 613 ssh_close_authentication_socket(agent_fd); 614 return ret; 615 } 616