1 /* $OpenBSD: ssh-add.c,v 1.109 2014/02/02 03:44:31 djm 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 62 /* argv0 */ 63 extern char *__progname; 64 65 /* Default files to add */ 66 static char *default_files[] = { 67 _PATH_SSH_CLIENT_ID_RSA, 68 _PATH_SSH_CLIENT_ID_DSA, 69 _PATH_SSH_CLIENT_ID_ECDSA, 70 _PATH_SSH_CLIENT_ID_ED25519, 71 _PATH_SSH_CLIENT_IDENTITY, 72 NULL 73 }; 74 75 /* Default lifetime (0 == forever) */ 76 static int lifetime = 0; 77 78 /* User has to confirm key use */ 79 static int confirm = 0; 80 81 /* we keep a cache of one passphrases */ 82 static char *pass = NULL; 83 static void 84 clear_pass(void) 85 { 86 if (pass) { 87 explicit_bzero(pass, strlen(pass)); 88 free(pass); 89 pass = NULL; 90 } 91 } 92 93 static int 94 delete_file(AuthenticationConnection *ac, const char *filename, int key_only) 95 { 96 Key *public = NULL, *cert = NULL; 97 char *certpath = NULL, *comment = NULL; 98 int ret = -1; 99 100 public = key_load_public(filename, &comment); 101 if (public == NULL) { 102 printf("Bad key file %s\n", filename); 103 return -1; 104 } 105 if (ssh_remove_identity(ac, public)) { 106 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment); 107 ret = 0; 108 } else 109 fprintf(stderr, "Could not remove identity: %s\n", filename); 110 111 if (key_only) 112 goto out; 113 114 /* Now try to delete the corresponding certificate too */ 115 free(comment); 116 comment = NULL; 117 xasprintf(&certpath, "%s-cert.pub", filename); 118 if ((cert = key_load_public(certpath, &comment)) == NULL) 119 goto out; 120 if (!key_equal_public(cert, public)) 121 fatal("Certificate %s does not match private key %s", 122 certpath, filename); 123 124 if (ssh_remove_identity(ac, cert)) { 125 fprintf(stderr, "Identity removed: %s (%s)\n", certpath, 126 comment); 127 ret = 0; 128 } else 129 fprintf(stderr, "Could not remove identity: %s\n", certpath); 130 131 out: 132 if (cert != NULL) 133 key_free(cert); 134 if (public != NULL) 135 key_free(public); 136 free(certpath); 137 free(comment); 138 139 return ret; 140 } 141 142 /* Send a request to remove all identities. */ 143 static int 144 delete_all(AuthenticationConnection *ac) 145 { 146 int ret = -1; 147 148 if (ssh_remove_all_identities(ac, 1)) 149 ret = 0; 150 /* ignore error-code for ssh2 */ 151 ssh_remove_all_identities(ac, 2); 152 153 if (ret == 0) 154 fprintf(stderr, "All identities removed.\n"); 155 else 156 fprintf(stderr, "Failed to remove all identities.\n"); 157 158 return ret; 159 } 160 161 static int 162 add_file(AuthenticationConnection *ac, const char *filename, int key_only) 163 { 164 Key *private, *cert; 165 char *comment = NULL; 166 char msg[1024], *certpath = NULL; 167 int fd, perms_ok, ret = -1; 168 Buffer keyblob; 169 170 if (strcmp(filename, "-") == 0) { 171 fd = STDIN_FILENO; 172 filename = "(stdin)"; 173 } else if ((fd = open(filename, O_RDONLY)) < 0) { 174 perror(filename); 175 return -1; 176 } 177 178 /* 179 * Since we'll try to load a keyfile multiple times, permission errors 180 * will occur multiple times, so check perms first and bail if wrong. 181 */ 182 if (fd != STDIN_FILENO) { 183 perms_ok = key_perm_ok(fd, filename); 184 if (!perms_ok) { 185 close(fd); 186 return -1; 187 } 188 } 189 buffer_init(&keyblob); 190 if (!key_load_file(fd, filename, &keyblob)) { 191 buffer_free(&keyblob); 192 close(fd); 193 return -1; 194 } 195 close(fd); 196 197 /* At first, try empty passphrase */ 198 private = key_parse_private(&keyblob, filename, "", &comment); 199 if (comment == NULL) 200 comment = xstrdup(filename); 201 /* try last */ 202 if (private == NULL && pass != NULL) 203 private = key_parse_private(&keyblob, filename, pass, NULL); 204 if (private == NULL) { 205 /* clear passphrase since it did not work */ 206 clear_pass(); 207 snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ", 208 comment); 209 for (;;) { 210 pass = read_passphrase(msg, RP_ALLOW_STDIN); 211 if (strcmp(pass, "") == 0) { 212 clear_pass(); 213 free(comment); 214 buffer_free(&keyblob); 215 return -1; 216 } 217 private = key_parse_private(&keyblob, filename, pass, 218 &comment); 219 if (private != NULL) 220 break; 221 clear_pass(); 222 snprintf(msg, sizeof msg, 223 "Bad passphrase, try again for %.200s: ", comment); 224 } 225 } 226 buffer_free(&keyblob); 227 228 if (ssh_add_identity_constrained(ac, private, comment, lifetime, 229 confirm)) { 230 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment); 231 ret = 0; 232 if (lifetime != 0) 233 fprintf(stderr, 234 "Lifetime set to %d seconds\n", lifetime); 235 if (confirm != 0) 236 fprintf(stderr, 237 "The user must confirm each use of the key\n"); 238 } else { 239 fprintf(stderr, "Could not add identity: %s\n", filename); 240 } 241 242 /* Skip trying to load the cert if requested */ 243 if (key_only) 244 goto out; 245 246 /* Now try to add the certificate flavour too */ 247 xasprintf(&certpath, "%s-cert.pub", filename); 248 if ((cert = key_load_public(certpath, NULL)) == NULL) 249 goto out; 250 251 if (!key_equal_public(cert, private)) { 252 error("Certificate %s does not match private key %s", 253 certpath, filename); 254 key_free(cert); 255 goto out; 256 } 257 258 /* Graft with private bits */ 259 if (key_to_certified(private, key_cert_is_legacy(cert)) != 0) { 260 error("%s: key_to_certified failed", __func__); 261 key_free(cert); 262 goto out; 263 } 264 key_cert_copy(cert, private); 265 key_free(cert); 266 267 if (!ssh_add_identity_constrained(ac, private, comment, 268 lifetime, confirm)) { 269 error("Certificate %s (%s) add failed", certpath, 270 private->cert->key_id); 271 } 272 fprintf(stderr, "Certificate added: %s (%s)\n", certpath, 273 private->cert->key_id); 274 if (lifetime != 0) 275 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime); 276 if (confirm != 0) 277 fprintf(stderr, "The user must confirm each use of the key\n"); 278 out: 279 if (certpath != NULL) 280 free(certpath); 281 free(comment); 282 key_free(private); 283 284 return ret; 285 } 286 287 static int 288 update_card(AuthenticationConnection *ac, int add, const char *id) 289 { 290 char *pin = NULL; 291 int ret = -1; 292 293 if (add) { 294 if ((pin = read_passphrase("Enter passphrase for PKCS#11: ", 295 RP_ALLOW_STDIN)) == NULL) 296 return -1; 297 } 298 299 if (ssh_update_card(ac, add, id, pin == NULL ? "" : pin, 300 lifetime, confirm)) { 301 fprintf(stderr, "Card %s: %s\n", 302 add ? "added" : "removed", id); 303 ret = 0; 304 } else { 305 fprintf(stderr, "Could not %s card: %s\n", 306 add ? "add" : "remove", id); 307 ret = -1; 308 } 309 free(pin); 310 return ret; 311 } 312 313 static int 314 list_identities(AuthenticationConnection *ac, int do_fp) 315 { 316 Key *key; 317 char *comment, *fp; 318 int had_identities = 0; 319 int version; 320 321 for (version = 1; version <= 2; version++) { 322 for (key = ssh_get_first_identity(ac, &comment, version); 323 key != NULL; 324 key = ssh_get_next_identity(ac, &comment, version)) { 325 had_identities = 1; 326 if (do_fp) { 327 fp = key_fingerprint(key, SSH_FP_MD5, 328 SSH_FP_HEX); 329 printf("%d %s %s (%s)\n", 330 key_size(key), fp, comment, key_type(key)); 331 free(fp); 332 } else { 333 if (!key_write(key, stdout)) 334 fprintf(stderr, "key_write failed"); 335 fprintf(stdout, " %s\n", comment); 336 } 337 key_free(key); 338 free(comment); 339 } 340 } 341 if (!had_identities) { 342 printf("The agent has no identities.\n"); 343 return -1; 344 } 345 return 0; 346 } 347 348 static int 349 lock_agent(AuthenticationConnection *ac, int lock) 350 { 351 char prompt[100], *p1, *p2; 352 int passok = 1, ret = -1; 353 354 strlcpy(prompt, "Enter lock password: ", sizeof(prompt)); 355 p1 = read_passphrase(prompt, RP_ALLOW_STDIN); 356 if (lock) { 357 strlcpy(prompt, "Again: ", sizeof prompt); 358 p2 = read_passphrase(prompt, RP_ALLOW_STDIN); 359 if (strcmp(p1, p2) != 0) { 360 fprintf(stderr, "Passwords do not match.\n"); 361 passok = 0; 362 } 363 explicit_bzero(p2, strlen(p2)); 364 free(p2); 365 } 366 if (passok && ssh_lock_agent(ac, lock, p1)) { 367 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un"); 368 ret = 0; 369 } else 370 fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un"); 371 explicit_bzero(p1, strlen(p1)); 372 free(p1); 373 return (ret); 374 } 375 376 static int 377 do_file(AuthenticationConnection *ac, int deleting, int key_only, char *file) 378 { 379 if (deleting) { 380 if (delete_file(ac, file, key_only) == -1) 381 return -1; 382 } else { 383 if (add_file(ac, file, key_only) == -1) 384 return -1; 385 } 386 return 0; 387 } 388 389 static void 390 usage(void) 391 { 392 fprintf(stderr, "usage: %s [options] [file ...]\n", __progname); 393 fprintf(stderr, "Options:\n"); 394 fprintf(stderr, " -l List fingerprints of all identities.\n"); 395 fprintf(stderr, " -L List public key parameters of all identities.\n"); 396 fprintf(stderr, " -k Load only keys and not certificates.\n"); 397 fprintf(stderr, " -c Require confirmation to sign using identities\n"); 398 fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n"); 399 fprintf(stderr, " -d Delete identity.\n"); 400 fprintf(stderr, " -D Delete all identities.\n"); 401 fprintf(stderr, " -x Lock agent.\n"); 402 fprintf(stderr, " -X Unlock agent.\n"); 403 fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n"); 404 fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n"); 405 } 406 407 int 408 main(int argc, char **argv) 409 { 410 extern char *optarg; 411 extern int optind; 412 AuthenticationConnection *ac = NULL; 413 char *pkcs11provider = NULL; 414 int i, ch, deleting = 0, ret = 0, key_only = 0; 415 416 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 417 sanitise_stdfd(); 418 419 OpenSSL_add_all_algorithms(); 420 421 /* At first, get a connection to the authentication agent. */ 422 ac = ssh_get_authentication_connection(); 423 if (ac == NULL) { 424 fprintf(stderr, 425 "Could not open a connection to your authentication agent.\n"); 426 exit(2); 427 } 428 while ((ch = getopt(argc, argv, "klLcdDxXe:s:t:")) != -1) { 429 switch (ch) { 430 case 'k': 431 key_only = 1; 432 break; 433 case 'l': 434 case 'L': 435 if (list_identities(ac, ch == 'l' ? 1 : 0) == -1) 436 ret = 1; 437 goto done; 438 case 'x': 439 case 'X': 440 if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1) 441 ret = 1; 442 goto done; 443 case 'c': 444 confirm = 1; 445 break; 446 case 'd': 447 deleting = 1; 448 break; 449 case 'D': 450 if (delete_all(ac) == -1) 451 ret = 1; 452 goto done; 453 case 's': 454 pkcs11provider = optarg; 455 break; 456 case 'e': 457 deleting = 1; 458 pkcs11provider = optarg; 459 break; 460 case 't': 461 if ((lifetime = convtime(optarg)) == -1) { 462 fprintf(stderr, "Invalid lifetime\n"); 463 ret = 1; 464 goto done; 465 } 466 break; 467 default: 468 usage(); 469 ret = 1; 470 goto done; 471 } 472 } 473 argc -= optind; 474 argv += optind; 475 if (pkcs11provider != NULL) { 476 if (update_card(ac, !deleting, pkcs11provider) == -1) 477 ret = 1; 478 goto done; 479 } 480 if (argc == 0) { 481 char buf[MAXPATHLEN]; 482 struct passwd *pw; 483 struct stat st; 484 int count = 0; 485 486 if ((pw = getpwuid(getuid())) == NULL) { 487 fprintf(stderr, "No user found with uid %u\n", 488 (u_int)getuid()); 489 ret = 1; 490 goto done; 491 } 492 493 for (i = 0; default_files[i]; i++) { 494 snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir, 495 default_files[i]); 496 if (stat(buf, &st) < 0) 497 continue; 498 if (do_file(ac, deleting, key_only, buf) == -1) 499 ret = 1; 500 else 501 count++; 502 } 503 if (count == 0) 504 ret = 1; 505 } else { 506 for (i = 0; i < argc; i++) { 507 if (do_file(ac, deleting, key_only, argv[i]) == -1) 508 ret = 1; 509 } 510 } 511 clear_pass(); 512 513 done: 514 ssh_close_authentication_connection(ac); 515 return ret; 516 } 517