1 /* $OpenBSD: ssh-add.c,v 1.103 2011/10/18 23:37:42 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 "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 66 /* argv0 */ 67 extern char *__progname; 68 69 /* Default files to add */ 70 static char *default_files[] = { 71 _PATH_SSH_CLIENT_ID_RSA, 72 _PATH_SSH_CLIENT_ID_DSA, 73 #ifdef OPENSSL_HAS_ECC 74 _PATH_SSH_CLIENT_ID_ECDSA, 75 #endif 76 _PATH_SSH_CLIENT_IDENTITY, 77 NULL 78 }; 79 80 /* Default lifetime (0 == forever) */ 81 static int lifetime = 0; 82 83 /* User has to confirm key use */ 84 static int confirm = 0; 85 86 /* we keep a cache of one passphrases */ 87 static char *pass = NULL; 88 static void 89 clear_pass(void) 90 { 91 if (pass) { 92 memset(pass, 0, strlen(pass)); 93 xfree(pass); 94 pass = NULL; 95 } 96 } 97 98 static int 99 delete_file(AuthenticationConnection *ac, const char *filename) 100 { 101 Key *public; 102 char *comment = NULL; 103 int ret = -1; 104 105 public = key_load_public(filename, &comment); 106 if (public == NULL) { 107 printf("Bad key file %s\n", filename); 108 return -1; 109 } 110 if (ssh_remove_identity(ac, public)) { 111 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment); 112 ret = 0; 113 } else 114 fprintf(stderr, "Could not remove identity: %s\n", filename); 115 116 key_free(public); 117 xfree(comment); 118 119 return ret; 120 } 121 122 /* Send a request to remove all identities. */ 123 static int 124 delete_all(AuthenticationConnection *ac) 125 { 126 int ret = -1; 127 128 if (ssh_remove_all_identities(ac, 1)) 129 ret = 0; 130 /* ignore error-code for ssh2 */ 131 ssh_remove_all_identities(ac, 2); 132 133 if (ret == 0) 134 fprintf(stderr, "All identities removed.\n"); 135 else 136 fprintf(stderr, "Failed to remove all identities.\n"); 137 138 return ret; 139 } 140 141 static int 142 add_file(AuthenticationConnection *ac, const char *filename, int key_only) 143 { 144 Key *private, *cert; 145 char *comment = NULL; 146 char msg[1024], *certpath = NULL; 147 int fd, perms_ok, ret = -1; 148 Buffer keyblob; 149 150 if (strcmp(filename, "-") == 0) { 151 fd = STDIN_FILENO; 152 filename = "(stdin)"; 153 } else if ((fd = open(filename, O_RDONLY)) < 0) { 154 perror(filename); 155 return -1; 156 } 157 158 /* 159 * Since we'll try to load a keyfile multiple times, permission errors 160 * will occur multiple times, so check perms first and bail if wrong. 161 */ 162 if (fd != STDIN_FILENO) { 163 perms_ok = key_perm_ok(fd, filename); 164 if (!perms_ok) { 165 close(fd); 166 return -1; 167 } 168 } 169 buffer_init(&keyblob); 170 if (!key_load_file(fd, filename, &keyblob)) { 171 buffer_free(&keyblob); 172 close(fd); 173 return -1; 174 } 175 close(fd); 176 177 /* At first, try empty passphrase */ 178 private = key_parse_private(&keyblob, filename, "", &comment); 179 if (comment == NULL) 180 comment = xstrdup(filename); 181 /* try last */ 182 if (private == NULL && pass != NULL) 183 private = key_parse_private(&keyblob, filename, pass, NULL); 184 if (private == NULL) { 185 /* clear passphrase since it did not work */ 186 clear_pass(); 187 snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ", 188 comment); 189 for (;;) { 190 pass = read_passphrase(msg, RP_ALLOW_STDIN); 191 if (strcmp(pass, "") == 0) { 192 clear_pass(); 193 xfree(comment); 194 buffer_free(&keyblob); 195 return -1; 196 } 197 private = key_parse_private(&keyblob, filename, pass, 198 &comment); 199 if (private != NULL) 200 break; 201 clear_pass(); 202 snprintf(msg, sizeof msg, 203 "Bad passphrase, try again for %.200s: ", comment); 204 } 205 } 206 buffer_free(&keyblob); 207 208 if (ssh_add_identity_constrained(ac, private, comment, lifetime, 209 confirm)) { 210 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment); 211 ret = 0; 212 if (lifetime != 0) 213 fprintf(stderr, 214 "Lifetime set to %d seconds\n", lifetime); 215 if (confirm != 0) 216 fprintf(stderr, 217 "The user must confirm each use of the key\n"); 218 } else { 219 fprintf(stderr, "Could not add identity: %s\n", filename); 220 } 221 222 /* Skip trying to load the cert if requested */ 223 if (key_only) 224 goto out; 225 226 /* Now try to add the certificate flavour too */ 227 xasprintf(&certpath, "%s-cert.pub", filename); 228 if ((cert = key_load_public(certpath, NULL)) == NULL) 229 goto out; 230 231 if (!key_equal_public(cert, private)) { 232 error("Certificate %s does not match private key %s", 233 certpath, filename); 234 key_free(cert); 235 goto out; 236 } 237 238 /* Graft with private bits */ 239 if (key_to_certified(private, key_cert_is_legacy(cert)) != 0) { 240 error("%s: key_to_certified failed", __func__); 241 key_free(cert); 242 goto out; 243 } 244 key_cert_copy(cert, private); 245 key_free(cert); 246 247 if (!ssh_add_identity_constrained(ac, private, comment, 248 lifetime, confirm)) { 249 error("Certificate %s (%s) add failed", certpath, 250 private->cert->key_id); 251 } 252 fprintf(stderr, "Certificate added: %s (%s)\n", certpath, 253 private->cert->key_id); 254 if (lifetime != 0) 255 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime); 256 if (confirm != 0) 257 fprintf(stderr, "The user must confirm each use of the key\n"); 258 out: 259 if (certpath != NULL) 260 xfree(certpath); 261 xfree(comment); 262 key_free(private); 263 264 return ret; 265 } 266 267 static int 268 update_card(AuthenticationConnection *ac, int add, const char *id) 269 { 270 char *pin; 271 int ret = -1; 272 273 pin = read_passphrase("Enter passphrase for PKCS#11: ", RP_ALLOW_STDIN); 274 if (pin == NULL) 275 return -1; 276 277 if (ssh_update_card(ac, add, id, pin, lifetime, confirm)) { 278 fprintf(stderr, "Card %s: %s\n", 279 add ? "added" : "removed", id); 280 ret = 0; 281 } else { 282 fprintf(stderr, "Could not %s card: %s\n", 283 add ? "add" : "remove", id); 284 ret = -1; 285 } 286 xfree(pin); 287 return ret; 288 } 289 290 static int 291 list_identities(AuthenticationConnection *ac, int do_fp) 292 { 293 Key *key; 294 char *comment, *fp; 295 int had_identities = 0; 296 int version; 297 298 for (version = 1; version <= 2; version++) { 299 for (key = ssh_get_first_identity(ac, &comment, version); 300 key != NULL; 301 key = ssh_get_next_identity(ac, &comment, version)) { 302 had_identities = 1; 303 if (do_fp) { 304 fp = key_fingerprint(key, SSH_FP_MD5, 305 SSH_FP_HEX); 306 printf("%d %s %s (%s)\n", 307 key_size(key), fp, comment, key_type(key)); 308 xfree(fp); 309 } else { 310 if (!key_write(key, stdout)) 311 fprintf(stderr, "key_write failed"); 312 fprintf(stdout, " %s\n", comment); 313 } 314 key_free(key); 315 xfree(comment); 316 } 317 } 318 if (!had_identities) { 319 printf("The agent has no identities.\n"); 320 return -1; 321 } 322 return 0; 323 } 324 325 static int 326 lock_agent(AuthenticationConnection *ac, int lock) 327 { 328 char prompt[100], *p1, *p2; 329 int passok = 1, ret = -1; 330 331 strlcpy(prompt, "Enter lock password: ", sizeof(prompt)); 332 p1 = read_passphrase(prompt, RP_ALLOW_STDIN); 333 if (lock) { 334 strlcpy(prompt, "Again: ", sizeof prompt); 335 p2 = read_passphrase(prompt, RP_ALLOW_STDIN); 336 if (strcmp(p1, p2) != 0) { 337 fprintf(stderr, "Passwords do not match.\n"); 338 passok = 0; 339 } 340 memset(p2, 0, strlen(p2)); 341 xfree(p2); 342 } 343 if (passok && ssh_lock_agent(ac, lock, p1)) { 344 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un"); 345 ret = 0; 346 } else 347 fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un"); 348 memset(p1, 0, strlen(p1)); 349 xfree(p1); 350 return (ret); 351 } 352 353 static int 354 do_file(AuthenticationConnection *ac, int deleting, int key_only, char *file) 355 { 356 if (deleting) { 357 if (delete_file(ac, file) == -1) 358 return -1; 359 } else { 360 if (add_file(ac, file, key_only) == -1) 361 return -1; 362 } 363 return 0; 364 } 365 366 static void 367 usage(void) 368 { 369 fprintf(stderr, "usage: %s [options] [file ...]\n", __progname); 370 fprintf(stderr, "Options:\n"); 371 fprintf(stderr, " -l List fingerprints of all identities.\n"); 372 fprintf(stderr, " -L List public key parameters of all identities.\n"); 373 fprintf(stderr, " -k Load only keys and not certificates.\n"); 374 fprintf(stderr, " -c Require confirmation to sign using identities\n"); 375 fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n"); 376 fprintf(stderr, " -d Delete identity.\n"); 377 fprintf(stderr, " -D Delete all identities.\n"); 378 fprintf(stderr, " -x Lock agent.\n"); 379 fprintf(stderr, " -X Unlock agent.\n"); 380 fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n"); 381 fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n"); 382 } 383 384 int 385 main(int argc, char **argv) 386 { 387 extern char *optarg; 388 extern int optind; 389 AuthenticationConnection *ac = NULL; 390 char *pkcs11provider = NULL; 391 int i, ch, deleting = 0, ret = 0, key_only = 0; 392 393 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 394 sanitise_stdfd(); 395 396 __progname = ssh_get_progname(argv[0]); 397 seed_rng(); 398 399 OpenSSL_add_all_algorithms(); 400 401 /* At first, get a connection to the authentication agent. */ 402 ac = ssh_get_authentication_connection(); 403 if (ac == NULL) { 404 fprintf(stderr, 405 "Could not open a connection to your authentication agent.\n"); 406 exit(2); 407 } 408 while ((ch = getopt(argc, argv, "klLcdDxXe:s:t:")) != -1) { 409 switch (ch) { 410 case 'k': 411 key_only = 1; 412 break; 413 case 'l': 414 case 'L': 415 if (list_identities(ac, ch == 'l' ? 1 : 0) == -1) 416 ret = 1; 417 goto done; 418 case 'x': 419 case 'X': 420 if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1) 421 ret = 1; 422 goto done; 423 case 'c': 424 confirm = 1; 425 break; 426 case 'd': 427 deleting = 1; 428 break; 429 case 'D': 430 if (delete_all(ac) == -1) 431 ret = 1; 432 goto done; 433 case 's': 434 pkcs11provider = optarg; 435 break; 436 case 'e': 437 deleting = 1; 438 pkcs11provider = optarg; 439 break; 440 case 't': 441 if ((lifetime = convtime(optarg)) == -1) { 442 fprintf(stderr, "Invalid lifetime\n"); 443 ret = 1; 444 goto done; 445 } 446 break; 447 default: 448 usage(); 449 ret = 1; 450 goto done; 451 } 452 } 453 argc -= optind; 454 argv += optind; 455 if (pkcs11provider != NULL) { 456 if (update_card(ac, !deleting, pkcs11provider) == -1) 457 ret = 1; 458 goto done; 459 } 460 if (argc == 0) { 461 char buf[MAXPATHLEN]; 462 struct passwd *pw; 463 struct stat st; 464 int count = 0; 465 466 if ((pw = getpwuid(getuid())) == NULL) { 467 fprintf(stderr, "No user found with uid %u\n", 468 (u_int)getuid()); 469 ret = 1; 470 goto done; 471 } 472 473 for (i = 0; default_files[i]; i++) { 474 snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir, 475 default_files[i]); 476 if (stat(buf, &st) < 0) 477 continue; 478 if (do_file(ac, deleting, key_only, buf) == -1) 479 ret = 1; 480 else 481 count++; 482 } 483 if (count == 0) 484 ret = 1; 485 } else { 486 for (i = 0; i < argc; i++) { 487 if (do_file(ac, deleting, key_only, argv[i]) == -1) 488 ret = 1; 489 } 490 } 491 clear_pass(); 492 493 done: 494 ssh_close_authentication_connection(ac); 495 return ret; 496 } 497