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 <sys/types.h> 39 #include <sys/stat.h> 40 #include <sys/param.h> 41 42 #include <openssl/evp.h> 43 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 51 #include "xmalloc.h" 52 #include "ssh.h" 53 #include "rsa.h" 54 #include "log.h" 55 #include "key.h" 56 #include "buffer.h" 57 #include "authfd.h" 58 #include "authfile.h" 59 #include "pathnames.h" 60 #include "misc.h" 61 #include "ssherr.h" 62 63 /* argv0 */ 64 extern char *__progname; 65 66 /* Default files to add */ 67 static char *default_files[] = { 68 _PATH_SSH_CLIENT_ID_RSA, 69 _PATH_SSH_CLIENT_ID_DSA, 70 _PATH_SSH_CLIENT_ID_ECDSA, 71 _PATH_SSH_CLIENT_ID_ED25519, 72 _PATH_SSH_CLIENT_IDENTITY, 73 NULL 74 }; 75 76 /* Default lifetime (0 == forever) */ 77 static int lifetime = 0; 78 79 /* User has to confirm key use */ 80 static int confirm = 0; 81 82 /* we keep a cache of one passphrases */ 83 static char *pass = NULL; 84 static void 85 clear_pass(void) 86 { 87 if (pass) { 88 explicit_bzero(pass, strlen(pass)); 89 free(pass); 90 pass = NULL; 91 } 92 } 93 94 static int 95 delete_file(AuthenticationConnection *ac, const char *filename, int key_only) 96 { 97 Key *public = NULL, *cert = NULL; 98 char *certpath = NULL, *comment = NULL; 99 int ret = -1; 100 101 public = key_load_public(filename, &comment); 102 if (public == NULL) { 103 printf("Bad key file %s\n", filename); 104 return -1; 105 } 106 if (ssh_remove_identity(ac, public)) { 107 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment); 108 ret = 0; 109 } else 110 fprintf(stderr, "Could not remove identity: %s\n", filename); 111 112 if (key_only) 113 goto out; 114 115 /* Now try to delete the corresponding certificate too */ 116 free(comment); 117 comment = NULL; 118 xasprintf(&certpath, "%s-cert.pub", filename); 119 if ((cert = key_load_public(certpath, &comment)) == NULL) 120 goto out; 121 if (!key_equal_public(cert, public)) 122 fatal("Certificate %s does not match private key %s", 123 certpath, filename); 124 125 if (ssh_remove_identity(ac, cert)) { 126 fprintf(stderr, "Identity removed: %s (%s)\n", certpath, 127 comment); 128 ret = 0; 129 } else 130 fprintf(stderr, "Could not remove identity: %s\n", certpath); 131 132 out: 133 if (cert != NULL) 134 key_free(cert); 135 if (public != NULL) 136 key_free(public); 137 free(certpath); 138 free(comment); 139 140 return ret; 141 } 142 143 /* Send a request to remove all identities. */ 144 static int 145 delete_all(AuthenticationConnection *ac) 146 { 147 int ret = -1; 148 149 if (ssh_remove_all_identities(ac, 1)) 150 ret = 0; 151 /* ignore error-code for ssh2 */ 152 ssh_remove_all_identities(ac, 2); 153 154 if (ret == 0) 155 fprintf(stderr, "All identities removed.\n"); 156 else 157 fprintf(stderr, "Failed to remove all identities.\n"); 158 159 return ret; 160 } 161 162 static int 163 add_file(AuthenticationConnection *ac, const char *filename, int key_only) 164 { 165 Key *private, *cert; 166 char *comment = NULL; 167 char msg[1024], *certpath = NULL; 168 int r, fd, perms_ok, ret = -1; 169 Buffer keyblob; 170 171 if (strcmp(filename, "-") == 0) { 172 fd = STDIN_FILENO; 173 filename = "(stdin)"; 174 } else if ((fd = open(filename, O_RDONLY)) < 0) { 175 perror(filename); 176 return -1; 177 } 178 179 /* 180 * Since we'll try to load a keyfile multiple times, permission errors 181 * will occur multiple times, so check perms first and bail if wrong. 182 */ 183 if (fd != STDIN_FILENO) { 184 perms_ok = key_perm_ok(fd, filename); 185 if (!perms_ok) { 186 close(fd); 187 return -1; 188 } 189 } 190 buffer_init(&keyblob); 191 if (!key_load_file(fd, filename, &keyblob)) { 192 buffer_free(&keyblob); 193 close(fd); 194 return -1; 195 } 196 close(fd); 197 198 /* At first, try empty passphrase */ 199 if ((r = sshkey_parse_private_fileblob(&keyblob, "", filename, 200 &private, &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) 201 fatal("Cannot parse %s: %s", filename, ssh_err(r)); 202 /* try last */ 203 if (private == NULL && pass != NULL) { 204 if ((r = sshkey_parse_private_fileblob(&keyblob, pass, filename, 205 &private, &comment)) != 0 && 206 r != SSH_ERR_KEY_WRONG_PASSPHRASE) 207 fatal("Cannot parse %s: %s", filename, ssh_err(r)); 208 } 209 if (comment == NULL) 210 comment = xstrdup(filename); 211 if (private == NULL) { 212 /* clear passphrase since it did not work */ 213 clear_pass(); 214 snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ", 215 comment); 216 for (;;) { 217 pass = read_passphrase(msg, RP_ALLOW_STDIN); 218 if (strcmp(pass, "") == 0) { 219 clear_pass(); 220 free(comment); 221 buffer_free(&keyblob); 222 return -1; 223 } 224 if ((r = sshkey_parse_private_fileblob(&keyblob, 225 pass, filename, &private, NULL)) != 0 && 226 r != SSH_ERR_KEY_WRONG_PASSPHRASE) 227 fatal("Cannot parse %s: %s", 228 filename, ssh_err(r)); 229 if (private != NULL) 230 break; 231 clear_pass(); 232 snprintf(msg, sizeof msg, 233 "Bad passphrase, try again for %.200s: ", comment); 234 } 235 } 236 buffer_free(&keyblob); 237 238 if (ssh_add_identity_constrained(ac, private, comment, lifetime, 239 confirm)) { 240 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment); 241 ret = 0; 242 if (lifetime != 0) 243 fprintf(stderr, 244 "Lifetime set to %d seconds\n", lifetime); 245 if (confirm != 0) 246 fprintf(stderr, 247 "The user must confirm each use of the key\n"); 248 } else { 249 fprintf(stderr, "Could not add identity: %s\n", filename); 250 } 251 252 /* Skip trying to load the cert if requested */ 253 if (key_only) 254 goto out; 255 256 /* Now try to add the certificate flavour too */ 257 xasprintf(&certpath, "%s-cert.pub", filename); 258 if ((cert = key_load_public(certpath, NULL)) == NULL) 259 goto out; 260 261 if (!key_equal_public(cert, private)) { 262 error("Certificate %s does not match private key %s", 263 certpath, filename); 264 key_free(cert); 265 goto out; 266 } 267 268 /* Graft with private bits */ 269 if (key_to_certified(private, key_cert_is_legacy(cert)) != 0) { 270 error("%s: key_to_certified failed", __func__); 271 key_free(cert); 272 goto out; 273 } 274 key_cert_copy(cert, private); 275 key_free(cert); 276 277 if (!ssh_add_identity_constrained(ac, private, comment, 278 lifetime, confirm)) { 279 error("Certificate %s (%s) add failed", certpath, 280 private->cert->key_id); 281 } 282 fprintf(stderr, "Certificate added: %s (%s)\n", certpath, 283 private->cert->key_id); 284 if (lifetime != 0) 285 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime); 286 if (confirm != 0) 287 fprintf(stderr, "The user must confirm each use of the key\n"); 288 out: 289 if (certpath != NULL) 290 free(certpath); 291 free(comment); 292 key_free(private); 293 294 return ret; 295 } 296 297 static int 298 update_card(AuthenticationConnection *ac, int add, const char *id) 299 { 300 char *pin = NULL; 301 int ret = -1; 302 303 if (add) { 304 if ((pin = read_passphrase("Enter passphrase for PKCS#11: ", 305 RP_ALLOW_STDIN)) == NULL) 306 return -1; 307 } 308 309 if (ssh_update_card(ac, add, id, pin == NULL ? "" : pin, 310 lifetime, confirm)) { 311 fprintf(stderr, "Card %s: %s\n", 312 add ? "added" : "removed", id); 313 ret = 0; 314 } else { 315 fprintf(stderr, "Could not %s card: %s\n", 316 add ? "add" : "remove", id); 317 ret = -1; 318 } 319 free(pin); 320 return ret; 321 } 322 323 static int 324 list_identities(AuthenticationConnection *ac, int do_fp) 325 { 326 Key *key; 327 char *comment, *fp; 328 int had_identities = 0; 329 int version; 330 331 for (version = 1; version <= 2; version++) { 332 for (key = ssh_get_first_identity(ac, &comment, version); 333 key != NULL; 334 key = ssh_get_next_identity(ac, &comment, version)) { 335 had_identities = 1; 336 if (do_fp) { 337 fp = key_fingerprint(key, SSH_FP_MD5, 338 SSH_FP_HEX); 339 printf("%d %s %s (%s)\n", 340 key_size(key), fp, comment, key_type(key)); 341 free(fp); 342 } else { 343 if (!key_write(key, stdout)) 344 fprintf(stderr, "key_write failed"); 345 fprintf(stdout, " %s\n", comment); 346 } 347 key_free(key); 348 free(comment); 349 } 350 } 351 if (!had_identities) { 352 printf("The agent has no identities.\n"); 353 return -1; 354 } 355 return 0; 356 } 357 358 static int 359 lock_agent(AuthenticationConnection *ac, int lock) 360 { 361 char prompt[100], *p1, *p2; 362 int passok = 1, ret = -1; 363 364 strlcpy(prompt, "Enter lock password: ", sizeof(prompt)); 365 p1 = read_passphrase(prompt, RP_ALLOW_STDIN); 366 if (lock) { 367 strlcpy(prompt, "Again: ", sizeof prompt); 368 p2 = read_passphrase(prompt, RP_ALLOW_STDIN); 369 if (strcmp(p1, p2) != 0) { 370 fprintf(stderr, "Passwords do not match.\n"); 371 passok = 0; 372 } 373 explicit_bzero(p2, strlen(p2)); 374 free(p2); 375 } 376 if (passok && ssh_lock_agent(ac, lock, p1)) { 377 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un"); 378 ret = 0; 379 } else 380 fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un"); 381 explicit_bzero(p1, strlen(p1)); 382 free(p1); 383 return (ret); 384 } 385 386 static int 387 do_file(AuthenticationConnection *ac, int deleting, int key_only, char *file) 388 { 389 if (deleting) { 390 if (delete_file(ac, file, key_only) == -1) 391 return -1; 392 } else { 393 if (add_file(ac, file, key_only) == -1) 394 return -1; 395 } 396 return 0; 397 } 398 399 static void 400 usage(void) 401 { 402 fprintf(stderr, "usage: %s [options] [file ...]\n", __progname); 403 fprintf(stderr, "Options:\n"); 404 fprintf(stderr, " -l List fingerprints of all identities.\n"); 405 fprintf(stderr, " -L List public key parameters of all identities.\n"); 406 fprintf(stderr, " -k Load only keys and not certificates.\n"); 407 fprintf(stderr, " -c Require confirmation to sign using identities\n"); 408 fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n"); 409 fprintf(stderr, " -d Delete identity.\n"); 410 fprintf(stderr, " -D Delete all identities.\n"); 411 fprintf(stderr, " -x Lock agent.\n"); 412 fprintf(stderr, " -X Unlock agent.\n"); 413 fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n"); 414 fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n"); 415 } 416 417 int 418 main(int argc, char **argv) 419 { 420 extern char *optarg; 421 extern int optind; 422 AuthenticationConnection *ac = NULL; 423 char *pkcs11provider = NULL; 424 int i, ch, deleting = 0, ret = 0, key_only = 0; 425 426 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 427 sanitise_stdfd(); 428 429 OpenSSL_add_all_algorithms(); 430 431 setlinebuf(stdout); 432 433 /* At first, get a connection to the authentication agent. */ 434 ac = ssh_get_authentication_connection(); 435 if (ac == NULL) { 436 fprintf(stderr, 437 "Could not open a connection to your authentication agent.\n"); 438 exit(2); 439 } 440 while ((ch = getopt(argc, argv, "klLcdDxXe:s:t:")) != -1) { 441 switch (ch) { 442 case 'k': 443 key_only = 1; 444 break; 445 case 'l': 446 case 'L': 447 if (list_identities(ac, ch == 'l' ? 1 : 0) == -1) 448 ret = 1; 449 goto done; 450 case 'x': 451 case 'X': 452 if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1) 453 ret = 1; 454 goto done; 455 case 'c': 456 confirm = 1; 457 break; 458 case 'd': 459 deleting = 1; 460 break; 461 case 'D': 462 if (delete_all(ac) == -1) 463 ret = 1; 464 goto done; 465 case 's': 466 pkcs11provider = optarg; 467 break; 468 case 'e': 469 deleting = 1; 470 pkcs11provider = optarg; 471 break; 472 case 't': 473 if ((lifetime = convtime(optarg)) == -1) { 474 fprintf(stderr, "Invalid lifetime\n"); 475 ret = 1; 476 goto done; 477 } 478 break; 479 default: 480 usage(); 481 ret = 1; 482 goto done; 483 } 484 } 485 argc -= optind; 486 argv += optind; 487 if (pkcs11provider != NULL) { 488 if (update_card(ac, !deleting, pkcs11provider) == -1) 489 ret = 1; 490 goto done; 491 } 492 if (argc == 0) { 493 char buf[MAXPATHLEN]; 494 struct passwd *pw; 495 struct stat st; 496 int count = 0; 497 498 if ((pw = getpwuid(getuid())) == NULL) { 499 fprintf(stderr, "No user found with uid %u\n", 500 (u_int)getuid()); 501 ret = 1; 502 goto done; 503 } 504 505 for (i = 0; default_files[i]; i++) { 506 snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir, 507 default_files[i]); 508 if (stat(buf, &st) < 0) 509 continue; 510 if (do_file(ac, deleting, key_only, buf) == -1) 511 ret = 1; 512 else 513 count++; 514 } 515 if (count == 0) 516 ret = 1; 517 } else { 518 for (i = 0; i < argc; i++) { 519 if (do_file(ac, deleting, key_only, argv[i]) == -1) 520 ret = 1; 521 } 522 } 523 clear_pass(); 524 525 done: 526 ssh_close_authentication_connection(ac); 527 return ret; 528 } 529