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