1 /* $OpenBSD: ssh-add.c,v 1.113 2014/07/09 14:15:56 benno 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 "includes.h" 39 40 #include <sys/types.h> 41 #include <sys/stat.h> 42 #include <sys/param.h> 43 44 #include <openssl/evp.h> 45 #include "openbsd-compat/openssl-compat.h" 46 47 #include <fcntl.h> 48 #include <pwd.h> 49 #include <stdarg.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <unistd.h> 54 55 #include "xmalloc.h" 56 #include "ssh.h" 57 #include "rsa.h" 58 #include "log.h" 59 #include "key.h" 60 #include "buffer.h" 61 #include "authfd.h" 62 #include "authfile.h" 63 #include "pathnames.h" 64 #include "misc.h" 65 #include "ssherr.h" 66 67 /* argv0 */ 68 extern char *__progname; 69 70 /* Default files to add */ 71 static char *default_files[] = { 72 _PATH_SSH_CLIENT_ID_RSA, 73 _PATH_SSH_CLIENT_ID_DSA, 74 #ifdef OPENSSL_HAS_ECC 75 _PATH_SSH_CLIENT_ID_ECDSA, 76 #endif 77 _PATH_SSH_CLIENT_ID_ED25519, 78 _PATH_SSH_CLIENT_IDENTITY, 79 NULL 80 }; 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(AuthenticationConnection *ac, const char *filename, int key_only) 102 { 103 Key *public = NULL, *cert = NULL; 104 char *certpath = NULL, *comment = NULL; 105 int ret = -1; 106 107 public = key_load_public(filename, &comment); 108 if (public == NULL) { 109 printf("Bad key file %s\n", filename); 110 return -1; 111 } 112 if (ssh_remove_identity(ac, public)) { 113 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment); 114 ret = 0; 115 } else 116 fprintf(stderr, "Could not remove identity: %s\n", filename); 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 ((cert = key_load_public(certpath, &comment)) == NULL) 126 goto out; 127 if (!key_equal_public(cert, public)) 128 fatal("Certificate %s does not match private key %s", 129 certpath, filename); 130 131 if (ssh_remove_identity(ac, cert)) { 132 fprintf(stderr, "Identity removed: %s (%s)\n", certpath, 133 comment); 134 ret = 0; 135 } else 136 fprintf(stderr, "Could not remove identity: %s\n", certpath); 137 138 out: 139 if (cert != NULL) 140 key_free(cert); 141 if (public != NULL) 142 key_free(public); 143 free(certpath); 144 free(comment); 145 146 return ret; 147 } 148 149 /* Send a request to remove all identities. */ 150 static int 151 delete_all(AuthenticationConnection *ac) 152 { 153 int ret = -1; 154 155 if (ssh_remove_all_identities(ac, 1)) 156 ret = 0; 157 /* ignore error-code for ssh2 */ 158 ssh_remove_all_identities(ac, 2); 159 160 if (ret == 0) 161 fprintf(stderr, "All identities removed.\n"); 162 else 163 fprintf(stderr, "Failed to remove all identities.\n"); 164 165 return ret; 166 } 167 168 static int 169 add_file(AuthenticationConnection *ac, const char *filename, int key_only) 170 { 171 Key *private, *cert; 172 char *comment = NULL; 173 char msg[1024], *certpath = NULL; 174 int r, fd, perms_ok, ret = -1; 175 Buffer keyblob; 176 177 if (strcmp(filename, "-") == 0) { 178 fd = STDIN_FILENO; 179 filename = "(stdin)"; 180 } else if ((fd = open(filename, O_RDONLY)) < 0) { 181 perror(filename); 182 return -1; 183 } 184 185 /* 186 * Since we'll try to load a keyfile multiple times, permission errors 187 * will occur multiple times, so check perms first and bail if wrong. 188 */ 189 if (fd != STDIN_FILENO) { 190 perms_ok = key_perm_ok(fd, filename); 191 if (!perms_ok) { 192 close(fd); 193 return -1; 194 } 195 } 196 buffer_init(&keyblob); 197 if (!key_load_file(fd, filename, &keyblob)) { 198 buffer_free(&keyblob); 199 close(fd); 200 return -1; 201 } 202 close(fd); 203 204 /* At first, try empty passphrase */ 205 if ((r = sshkey_parse_private_fileblob(&keyblob, "", filename, 206 &private, &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) 207 fatal("Cannot parse %s: %s", filename, ssh_err(r)); 208 /* try last */ 209 if (private == NULL && pass != NULL) { 210 if ((r = sshkey_parse_private_fileblob(&keyblob, pass, filename, 211 &private, &comment)) != 0 && 212 r != SSH_ERR_KEY_WRONG_PASSPHRASE) 213 fatal("Cannot parse %s: %s", filename, ssh_err(r)); 214 } 215 if (comment == NULL) 216 comment = xstrdup(filename); 217 if (private == NULL) { 218 /* clear passphrase since it did not work */ 219 clear_pass(); 220 snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ", 221 comment); 222 for (;;) { 223 pass = read_passphrase(msg, RP_ALLOW_STDIN); 224 if (strcmp(pass, "") == 0) { 225 clear_pass(); 226 free(comment); 227 buffer_free(&keyblob); 228 return -1; 229 } 230 if ((r = sshkey_parse_private_fileblob(&keyblob, 231 pass, filename, &private, NULL)) != 0 && 232 r != SSH_ERR_KEY_WRONG_PASSPHRASE) 233 fatal("Cannot parse %s: %s", 234 filename, ssh_err(r)); 235 if (private != NULL) 236 break; 237 clear_pass(); 238 snprintf(msg, sizeof msg, 239 "Bad passphrase, try again for %.200s: ", comment); 240 } 241 } 242 buffer_free(&keyblob); 243 244 if (ssh_add_identity_constrained(ac, private, comment, lifetime, 245 confirm)) { 246 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment); 247 ret = 0; 248 if (lifetime != 0) 249 fprintf(stderr, 250 "Lifetime set to %d seconds\n", lifetime); 251 if (confirm != 0) 252 fprintf(stderr, 253 "The user must confirm each use of the key\n"); 254 } else { 255 fprintf(stderr, "Could not add identity: %s\n", filename); 256 } 257 258 /* Skip trying to load the cert if requested */ 259 if (key_only) 260 goto out; 261 262 /* Now try to add the certificate flavour too */ 263 xasprintf(&certpath, "%s-cert.pub", filename); 264 if ((cert = key_load_public(certpath, NULL)) == NULL) 265 goto out; 266 267 if (!key_equal_public(cert, private)) { 268 error("Certificate %s does not match private key %s", 269 certpath, filename); 270 key_free(cert); 271 goto out; 272 } 273 274 /* Graft with private bits */ 275 if (key_to_certified(private, key_cert_is_legacy(cert)) != 0) { 276 error("%s: key_to_certified failed", __func__); 277 key_free(cert); 278 goto out; 279 } 280 key_cert_copy(cert, private); 281 key_free(cert); 282 283 if (!ssh_add_identity_constrained(ac, private, comment, 284 lifetime, confirm)) { 285 error("Certificate %s (%s) add failed", certpath, 286 private->cert->key_id); 287 } 288 fprintf(stderr, "Certificate added: %s (%s)\n", certpath, 289 private->cert->key_id); 290 if (lifetime != 0) 291 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime); 292 if (confirm != 0) 293 fprintf(stderr, "The user must confirm each use of the key\n"); 294 out: 295 if (certpath != NULL) 296 free(certpath); 297 free(comment); 298 key_free(private); 299 300 return ret; 301 } 302 303 static int 304 update_card(AuthenticationConnection *ac, int add, const char *id) 305 { 306 char *pin = NULL; 307 int ret = -1; 308 309 if (add) { 310 if ((pin = read_passphrase("Enter passphrase for PKCS#11: ", 311 RP_ALLOW_STDIN)) == NULL) 312 return -1; 313 } 314 315 if (ssh_update_card(ac, add, id, pin == NULL ? "" : pin, 316 lifetime, confirm)) { 317 fprintf(stderr, "Card %s: %s\n", 318 add ? "added" : "removed", id); 319 ret = 0; 320 } else { 321 fprintf(stderr, "Could not %s card: %s\n", 322 add ? "add" : "remove", id); 323 ret = -1; 324 } 325 free(pin); 326 return ret; 327 } 328 329 static int 330 list_identities(AuthenticationConnection *ac, int do_fp) 331 { 332 Key *key; 333 char *comment, *fp; 334 int had_identities = 0; 335 int version; 336 337 for (version = 1; version <= 2; version++) { 338 for (key = ssh_get_first_identity(ac, &comment, version); 339 key != NULL; 340 key = ssh_get_next_identity(ac, &comment, version)) { 341 had_identities = 1; 342 if (do_fp) { 343 fp = key_fingerprint(key, SSH_FP_MD5, 344 SSH_FP_HEX); 345 printf("%d %s %s (%s)\n", 346 key_size(key), fp, comment, key_type(key)); 347 free(fp); 348 } else { 349 if (!key_write(key, stdout)) 350 fprintf(stderr, "key_write failed"); 351 fprintf(stdout, " %s\n", comment); 352 } 353 key_free(key); 354 free(comment); 355 } 356 } 357 if (!had_identities) { 358 printf("The agent has no identities.\n"); 359 return -1; 360 } 361 return 0; 362 } 363 364 static int 365 lock_agent(AuthenticationConnection *ac, int lock) 366 { 367 char prompt[100], *p1, *p2; 368 int passok = 1, ret = -1; 369 370 strlcpy(prompt, "Enter lock password: ", sizeof(prompt)); 371 p1 = read_passphrase(prompt, RP_ALLOW_STDIN); 372 if (lock) { 373 strlcpy(prompt, "Again: ", sizeof prompt); 374 p2 = read_passphrase(prompt, RP_ALLOW_STDIN); 375 if (strcmp(p1, p2) != 0) { 376 fprintf(stderr, "Passwords do not match.\n"); 377 passok = 0; 378 } 379 explicit_bzero(p2, strlen(p2)); 380 free(p2); 381 } 382 if (passok && ssh_lock_agent(ac, lock, p1)) { 383 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un"); 384 ret = 0; 385 } else 386 fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un"); 387 explicit_bzero(p1, strlen(p1)); 388 free(p1); 389 return (ret); 390 } 391 392 static int 393 do_file(AuthenticationConnection *ac, int deleting, int key_only, char *file) 394 { 395 if (deleting) { 396 if (delete_file(ac, file, key_only) == -1) 397 return -1; 398 } else { 399 if (add_file(ac, file, key_only) == -1) 400 return -1; 401 } 402 return 0; 403 } 404 405 static void 406 usage(void) 407 { 408 fprintf(stderr, "usage: %s [options] [file ...]\n", __progname); 409 fprintf(stderr, "Options:\n"); 410 fprintf(stderr, " -l List fingerprints of all identities.\n"); 411 fprintf(stderr, " -L List public key parameters of all identities.\n"); 412 fprintf(stderr, " -k Load only keys and not certificates.\n"); 413 fprintf(stderr, " -c Require confirmation to sign using identities\n"); 414 fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n"); 415 fprintf(stderr, " -d Delete identity.\n"); 416 fprintf(stderr, " -D Delete all identities.\n"); 417 fprintf(stderr, " -x Lock agent.\n"); 418 fprintf(stderr, " -X Unlock agent.\n"); 419 fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n"); 420 fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n"); 421 } 422 423 int 424 main(int argc, char **argv) 425 { 426 extern char *optarg; 427 extern int optind; 428 AuthenticationConnection *ac = NULL; 429 char *pkcs11provider = NULL; 430 int i, ch, deleting = 0, ret = 0, key_only = 0; 431 432 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 433 sanitise_stdfd(); 434 435 __progname = ssh_get_progname(argv[0]); 436 seed_rng(); 437 438 OpenSSL_add_all_algorithms(); 439 440 setlinebuf(stdout); 441 442 /* At first, get a connection to the authentication agent. */ 443 ac = ssh_get_authentication_connection(); 444 if (ac == NULL) { 445 fprintf(stderr, 446 "Could not open a connection to your authentication agent.\n"); 447 exit(2); 448 } 449 while ((ch = getopt(argc, argv, "klLcdDxXe:s:t:")) != -1) { 450 switch (ch) { 451 case 'k': 452 key_only = 1; 453 break; 454 case 'l': 455 case 'L': 456 if (list_identities(ac, ch == 'l' ? 1 : 0) == -1) 457 ret = 1; 458 goto done; 459 case 'x': 460 case 'X': 461 if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1) 462 ret = 1; 463 goto done; 464 case 'c': 465 confirm = 1; 466 break; 467 case 'd': 468 deleting = 1; 469 break; 470 case 'D': 471 if (delete_all(ac) == -1) 472 ret = 1; 473 goto done; 474 case 's': 475 pkcs11provider = optarg; 476 break; 477 case 'e': 478 deleting = 1; 479 pkcs11provider = optarg; 480 break; 481 case 't': 482 if ((lifetime = convtime(optarg)) == -1) { 483 fprintf(stderr, "Invalid lifetime\n"); 484 ret = 1; 485 goto done; 486 } 487 break; 488 default: 489 usage(); 490 ret = 1; 491 goto done; 492 } 493 } 494 argc -= optind; 495 argv += optind; 496 if (pkcs11provider != NULL) { 497 if (update_card(ac, !deleting, pkcs11provider) == -1) 498 ret = 1; 499 goto done; 500 } 501 if (argc == 0) { 502 char buf[MAXPATHLEN]; 503 struct passwd *pw; 504 struct stat st; 505 int count = 0; 506 507 if ((pw = getpwuid(getuid())) == NULL) { 508 fprintf(stderr, "No user found with uid %u\n", 509 (u_int)getuid()); 510 ret = 1; 511 goto done; 512 } 513 514 for (i = 0; default_files[i]; i++) { 515 snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir, 516 default_files[i]); 517 if (stat(buf, &st) < 0) 518 continue; 519 if (do_file(ac, deleting, key_only, buf) == -1) 520 ret = 1; 521 else 522 count++; 523 } 524 if (count == 0) 525 ret = 1; 526 } else { 527 for (i = 0; i < argc; i++) { 528 if (do_file(ac, deleting, key_only, argv[i]) == -1) 529 ret = 1; 530 } 531 } 532 clear_pass(); 533 534 done: 535 ssh_close_authentication_connection(ac); 536 return ret; 537 } 538