1 /* $NetBSD: ssh-add.c,v 1.6 2012/05/02 02:41:08 christos 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 __RCSID("$NetBSD: ssh-add.c,v 1.6 2012/05/02 02:41:08 christos Exp $"); 40 #include <sys/types.h> 41 #include <sys/stat.h> 42 #include <sys/param.h> 43 44 #include <openssl/evp.h> 45 46 #include <fcntl.h> 47 #include <pwd.h> 48 #include <stdio.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <unistd.h> 52 53 #include "xmalloc.h" 54 #include "ssh.h" 55 #include "rsa.h" 56 #include "log.h" 57 #include "key.h" 58 #include "buffer.h" 59 #include "authfd.h" 60 #include "authfile.h" 61 #include "pathnames.h" 62 #include "misc.h" 63 64 /* argv0 */ 65 extern char *__progname; 66 67 /* Default files to add */ 68 static const char *default_files[] = { 69 _PATH_SSH_CLIENT_ID_RSA, 70 _PATH_SSH_CLIENT_ID_DSA, 71 _PATH_SSH_CLIENT_ID_ECDSA, 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 memset(pass, 0, strlen(pass)); 89 xfree(pass); 90 pass = NULL; 91 } 92 } 93 94 static int 95 delete_file(AuthenticationConnection *ac, const char *filename) 96 { 97 Key *public; 98 char *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 key_free(public); 113 xfree(comment); 114 115 return ret; 116 } 117 118 /* Send a request to remove all identities. */ 119 static int 120 delete_all(AuthenticationConnection *ac) 121 { 122 int ret = -1; 123 124 if (ssh_remove_all_identities(ac, 1)) 125 ret = 0; 126 /* ignore error-code for ssh2 */ 127 ssh_remove_all_identities(ac, 2); 128 129 if (ret == 0) 130 fprintf(stderr, "All identities removed.\n"); 131 else 132 fprintf(stderr, "Failed to remove all identities.\n"); 133 134 return ret; 135 } 136 137 static int 138 add_file(AuthenticationConnection *ac, const char *filename, int key_only) 139 { 140 Key *private, *cert; 141 char *comment = NULL; 142 char msg[1024], *certpath = NULL; 143 int fd, perms_ok, ret = -1; 144 Buffer keyblob; 145 146 if (strcmp(filename, "-") == 0) { 147 fd = STDIN_FILENO; 148 filename = "(stdin)"; 149 } else if ((fd = open(filename, O_RDONLY)) < 0) { 150 perror(filename); 151 return -1; 152 } 153 154 /* 155 * Since we'll try to load a keyfile multiple times, permission errors 156 * will occur multiple times, so check perms first and bail if wrong. 157 */ 158 if (fd != STDIN_FILENO) { 159 perms_ok = key_perm_ok(fd, filename); 160 if (!perms_ok) { 161 close(fd); 162 return -1; 163 } 164 } 165 buffer_init(&keyblob); 166 if (!key_load_file(fd, filename, &keyblob)) { 167 buffer_free(&keyblob); 168 close(fd); 169 return -1; 170 } 171 close(fd); 172 173 /* At first, try empty passphrase */ 174 private = key_parse_private(&keyblob, filename, "", &comment); 175 if (comment == NULL) 176 comment = xstrdup(filename); 177 /* try last */ 178 if (private == NULL && pass != NULL) 179 private = key_parse_private(&keyblob, filename, pass, NULL); 180 if (private == NULL) { 181 /* clear passphrase since it did not work */ 182 clear_pass(); 183 snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ", 184 comment); 185 for (;;) { 186 pass = read_passphrase(msg, RP_ALLOW_STDIN); 187 if (strcmp(pass, "") == 0) { 188 clear_pass(); 189 xfree(comment); 190 buffer_free(&keyblob); 191 return -1; 192 } 193 private = key_parse_private(&keyblob, filename, pass, 194 &comment); 195 if (private != NULL) 196 break; 197 clear_pass(); 198 snprintf(msg, sizeof msg, 199 "Bad passphrase, try again for %.200s: ", comment); 200 } 201 } 202 buffer_free(&keyblob); 203 204 if (ssh_add_identity_constrained(ac, private, comment, lifetime, 205 confirm)) { 206 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment); 207 ret = 0; 208 if (lifetime != 0) 209 fprintf(stderr, 210 "Lifetime set to %d seconds\n", lifetime); 211 if (confirm != 0) 212 fprintf(stderr, 213 "The user must confirm each use of the key\n"); 214 } else { 215 fprintf(stderr, "Could not add identity: %s\n", filename); 216 } 217 218 /* Skip trying to load the cert if requested */ 219 if (key_only) 220 goto out; 221 222 /* Now try to add the certificate flavour too */ 223 xasprintf(&certpath, "%s-cert.pub", filename); 224 if ((cert = key_load_public(certpath, NULL)) == NULL) 225 goto out; 226 227 if (!key_equal_public(cert, private)) { 228 error("Certificate %s does not match private key %s", 229 certpath, filename); 230 key_free(cert); 231 goto out; 232 } 233 234 /* Graft with private bits */ 235 if (key_to_certified(private, key_cert_is_legacy(cert)) != 0) { 236 error("%s: key_to_certified failed", __func__); 237 key_free(cert); 238 goto out; 239 } 240 key_cert_copy(cert, private); 241 key_free(cert); 242 243 if (!ssh_add_identity_constrained(ac, private, comment, 244 lifetime, confirm)) { 245 error("Certificate %s (%s) add failed", certpath, 246 private->cert->key_id); 247 } 248 fprintf(stderr, "Certificate added: %s (%s)\n", certpath, 249 private->cert->key_id); 250 if (lifetime != 0) 251 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime); 252 if (confirm != 0) 253 fprintf(stderr, "The user must confirm each use of the key\n"); 254 out: 255 if (certpath != NULL) 256 xfree(certpath); 257 xfree(comment); 258 key_free(private); 259 260 return ret; 261 } 262 263 static int 264 update_card(AuthenticationConnection *ac, int add, const char *id) 265 { 266 char *pin; 267 int ret = -1; 268 269 pin = read_passphrase("Enter passphrase for PKCS#11: ", RP_ALLOW_STDIN); 270 if (pin == NULL) 271 return -1; 272 273 if (ssh_update_card(ac, add, id, pin, lifetime, confirm)) { 274 fprintf(stderr, "Card %s: %s\n", 275 add ? "added" : "removed", id); 276 ret = 0; 277 } else { 278 fprintf(stderr, "Could not %s card: %s\n", 279 add ? "add" : "remove", id); 280 ret = -1; 281 } 282 xfree(pin); 283 return ret; 284 } 285 286 static int 287 list_identities(AuthenticationConnection *ac, int do_fp) 288 { 289 Key *key; 290 char *comment, *fp; 291 int had_identities = 0; 292 int version; 293 294 for (version = 1; version <= 2; version++) { 295 for (key = ssh_get_first_identity(ac, &comment, version); 296 key != NULL; 297 key = ssh_get_next_identity(ac, &comment, version)) { 298 had_identities = 1; 299 if (do_fp) { 300 fp = key_fingerprint(key, SSH_FP_MD5, 301 SSH_FP_HEX); 302 printf("%d %s %s (%s)\n", 303 key_size(key), fp, comment, key_type(key)); 304 xfree(fp); 305 } else { 306 if (!key_write(key, stdout)) 307 fprintf(stderr, "key_write failed"); 308 fprintf(stdout, " %s\n", comment); 309 } 310 key_free(key); 311 xfree(comment); 312 } 313 } 314 if (!had_identities) { 315 printf("The agent has no identities.\n"); 316 return -1; 317 } 318 return 0; 319 } 320 321 static int 322 lock_agent(AuthenticationConnection *ac, int lock) 323 { 324 char prompt[100], *p1, *p2; 325 int passok = 1, ret = -1; 326 327 strlcpy(prompt, "Enter lock password: ", sizeof(prompt)); 328 p1 = read_passphrase(prompt, RP_ALLOW_STDIN); 329 if (lock) { 330 strlcpy(prompt, "Again: ", sizeof prompt); 331 p2 = read_passphrase(prompt, RP_ALLOW_STDIN); 332 if (strcmp(p1, p2) != 0) { 333 fprintf(stderr, "Passwords do not match.\n"); 334 passok = 0; 335 } 336 memset(p2, 0, strlen(p2)); 337 xfree(p2); 338 } 339 if (passok && ssh_lock_agent(ac, lock, p1)) { 340 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un"); 341 ret = 0; 342 } else 343 fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un"); 344 memset(p1, 0, strlen(p1)); 345 xfree(p1); 346 return (ret); 347 } 348 349 static int 350 do_file(AuthenticationConnection *ac, int deleting, int key_only, char *file) 351 { 352 if (deleting) { 353 if (delete_file(ac, file) == -1) 354 return -1; 355 } else { 356 if (add_file(ac, file, key_only) == -1) 357 return -1; 358 } 359 return 0; 360 } 361 362 static void 363 usage(void) 364 { 365 fprintf(stderr, "usage: %s [options] [file ...]\n", __progname); 366 fprintf(stderr, "Options:\n"); 367 fprintf(stderr, " -l List fingerprints of all identities.\n"); 368 fprintf(stderr, " -L List public key parameters of all identities.\n"); 369 fprintf(stderr, " -k Load only keys and not certificates.\n"); 370 fprintf(stderr, " -c Require confirmation to sign using identities\n"); 371 fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n"); 372 fprintf(stderr, " -d Delete identity.\n"); 373 fprintf(stderr, " -D Delete all identities.\n"); 374 fprintf(stderr, " -x Lock agent.\n"); 375 fprintf(stderr, " -X Unlock agent.\n"); 376 fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n"); 377 fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n"); 378 } 379 380 int 381 main(int argc, char **argv) 382 { 383 extern char *optarg; 384 extern int optind; 385 AuthenticationConnection *ac = NULL; 386 char *pkcs11provider = NULL; 387 int i, ch, deleting = 0, ret = 0, key_only = 0; 388 389 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 390 sanitise_stdfd(); 391 392 OpenSSL_add_all_algorithms(); 393 394 /* At first, get a connection to the authentication agent. */ 395 ac = ssh_get_authentication_connection(); 396 if (ac == NULL) { 397 fprintf(stderr, 398 "Could not open a connection to your authentication agent.\n"); 399 exit(2); 400 } 401 while ((ch = getopt(argc, argv, "klLcdDxXe:s:t:")) != -1) { 402 switch (ch) { 403 case 'k': 404 key_only = 1; 405 break; 406 case 'l': 407 case 'L': 408 if (list_identities(ac, ch == 'l' ? 1 : 0) == -1) 409 ret = 1; 410 goto done; 411 case 'x': 412 case 'X': 413 if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1) 414 ret = 1; 415 goto done; 416 case 'c': 417 confirm = 1; 418 break; 419 case 'd': 420 deleting = 1; 421 break; 422 case 'D': 423 if (delete_all(ac) == -1) 424 ret = 1; 425 goto done; 426 case 's': 427 pkcs11provider = optarg; 428 break; 429 case 'e': 430 deleting = 1; 431 pkcs11provider = optarg; 432 break; 433 case 't': 434 if ((lifetime = convtime(optarg)) == -1) { 435 fprintf(stderr, "Invalid lifetime\n"); 436 ret = 1; 437 goto done; 438 } 439 break; 440 default: 441 usage(); 442 ret = 1; 443 goto done; 444 } 445 } 446 argc -= optind; 447 argv += optind; 448 if (pkcs11provider != NULL) { 449 if (update_card(ac, !deleting, pkcs11provider) == -1) 450 ret = 1; 451 goto done; 452 } 453 if (argc == 0) { 454 char buf[MAXPATHLEN]; 455 struct passwd *pw; 456 struct stat st; 457 int count = 0; 458 459 if ((pw = getpwuid(getuid())) == NULL) { 460 fprintf(stderr, "No user found with uid %u\n", 461 (u_int)getuid()); 462 ret = 1; 463 goto done; 464 } 465 466 for (i = 0; default_files[i]; i++) { 467 snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir, 468 default_files[i]); 469 if (stat(buf, &st) < 0) 470 continue; 471 if (do_file(ac, deleting, key_only, buf) == -1) 472 ret = 1; 473 else 474 count++; 475 } 476 if (count == 0) 477 ret = 1; 478 } else { 479 for (i = 0; i < argc; i++) { 480 if (do_file(ac, deleting, key_only, argv[i]) == -1) 481 ret = 1; 482 } 483 } 484 clear_pass(); 485 486 done: 487 ssh_close_authentication_connection(ac); 488 return ret; 489 } 490