1 /* $NetBSD: ssh-add.c,v 1.8 2013/11/08 19:18:25 christos Exp $ */ 2 /* $OpenBSD: ssh-add.c,v 1.106 2013/05/17 00:13:14 djm Exp $ */ 3 /* 4 * Author: Tatu Ylonen <ylo@cs.hut.fi> 5 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 6 * All rights reserved 7 * Adds an identity to the authentication server, or removes an identity. 8 * 9 * As far as I am concerned, the code I have written for this software 10 * can be used freely for any purpose. Any derived versions of this 11 * software must be clearly marked as such, and if the derived work is 12 * incompatible with the protocol description in the RFC file, it must be 13 * called by a name other than "ssh" or "Secure Shell". 14 * 15 * SSH2 implementation, 16 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions 20 * are met: 21 * 1. Redistributions of source code must retain the above copyright 22 * notice, this list of conditions and the following disclaimer. 23 * 2. Redistributions in binary form must reproduce the above copyright 24 * notice, this list of conditions and the following disclaimer in the 25 * documentation and/or other materials provided with the distribution. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 28 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 29 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 30 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 31 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 32 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 33 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 34 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 35 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 36 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include "includes.h" 40 __RCSID("$NetBSD: ssh-add.c,v 1.8 2013/11/08 19:18:25 christos Exp $"); 41 #include <sys/types.h> 42 #include <sys/stat.h> 43 #include <sys/param.h> 44 45 #include <openssl/evp.h> 46 47 #include <fcntl.h> 48 #include <pwd.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <unistd.h> 53 54 #include "xmalloc.h" 55 #include "ssh.h" 56 #include "rsa.h" 57 #include "log.h" 58 #include "key.h" 59 #include "buffer.h" 60 #include "authfd.h" 61 #include "authfile.h" 62 #include "pathnames.h" 63 #include "misc.h" 64 65 /* argv0 */ 66 extern char *__progname; 67 68 /* Default files to add */ 69 static const char *default_files[] = { 70 _PATH_SSH_CLIENT_ID_RSA, 71 _PATH_SSH_CLIENT_ID_DSA, 72 _PATH_SSH_CLIENT_ID_ECDSA, 73 _PATH_SSH_CLIENT_IDENTITY, 74 NULL 75 }; 76 77 /* Default lifetime (0 == forever) */ 78 static int lifetime = 0; 79 80 /* User has to confirm key use */ 81 static int confirm = 0; 82 83 /* we keep a cache of one passphrases */ 84 static char *pass = NULL; 85 static void 86 clear_pass(void) 87 { 88 if (pass) { 89 memset(pass, 0, strlen(pass)); 90 free(pass); 91 pass = NULL; 92 } 93 } 94 95 static int 96 delete_file(AuthenticationConnection *ac, const char *filename, int key_only) 97 { 98 Key *public = NULL, *cert = NULL; 99 char *certpath = NULL, *comment = NULL; 100 int ret = -1; 101 102 public = key_load_public(filename, &comment); 103 if (public == NULL) { 104 printf("Bad key file %s\n", filename); 105 return -1; 106 } 107 if (ssh_remove_identity(ac, public)) { 108 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment); 109 ret = 0; 110 } else 111 fprintf(stderr, "Could not remove identity: %s\n", filename); 112 113 if (key_only) 114 goto out; 115 116 /* Now try to delete the corresponding certificate too */ 117 free(comment); 118 comment = NULL; 119 xasprintf(&certpath, "%s-cert.pub", filename); 120 if ((cert = key_load_public(certpath, &comment)) == NULL) 121 goto out; 122 if (!key_equal_public(cert, public)) 123 fatal("Certificate %s does not match private key %s", 124 certpath, filename); 125 126 if (ssh_remove_identity(ac, cert)) { 127 fprintf(stderr, "Identity removed: %s (%s)\n", certpath, 128 comment); 129 ret = 0; 130 } else 131 fprintf(stderr, "Could not remove identity: %s\n", certpath); 132 133 out: 134 if (cert != NULL) 135 key_free(cert); 136 if (public != NULL) 137 key_free(public); 138 free(certpath); 139 free(comment); 140 141 return ret; 142 } 143 144 /* Send a request to remove all identities. */ 145 static int 146 delete_all(AuthenticationConnection *ac) 147 { 148 int ret = -1; 149 150 if (ssh_remove_all_identities(ac, 1)) 151 ret = 0; 152 /* ignore error-code for ssh2 */ 153 ssh_remove_all_identities(ac, 2); 154 155 if (ret == 0) 156 fprintf(stderr, "All identities removed.\n"); 157 else 158 fprintf(stderr, "Failed to remove all identities.\n"); 159 160 return ret; 161 } 162 163 static int 164 add_file(AuthenticationConnection *ac, const char *filename, int key_only) 165 { 166 Key *private, *cert; 167 char *comment = NULL; 168 char msg[1024], *certpath = NULL; 169 int fd, perms_ok, ret = -1; 170 Buffer keyblob; 171 172 if (strcmp(filename, "-") == 0) { 173 fd = STDIN_FILENO; 174 filename = "(stdin)"; 175 } else if ((fd = open(filename, O_RDONLY)) < 0) { 176 perror(filename); 177 return -1; 178 } 179 180 /* 181 * Since we'll try to load a keyfile multiple times, permission errors 182 * will occur multiple times, so check perms first and bail if wrong. 183 */ 184 if (fd != STDIN_FILENO) { 185 perms_ok = key_perm_ok(fd, filename); 186 if (!perms_ok) { 187 close(fd); 188 return -1; 189 } 190 } 191 buffer_init(&keyblob); 192 if (!key_load_file(fd, filename, &keyblob)) { 193 buffer_free(&keyblob); 194 close(fd); 195 return -1; 196 } 197 close(fd); 198 199 /* At first, try empty passphrase */ 200 private = key_parse_private(&keyblob, filename, "", &comment); 201 if (comment == NULL) 202 comment = xstrdup(filename); 203 /* try last */ 204 if (private == NULL && pass != NULL) 205 private = key_parse_private(&keyblob, filename, pass, NULL); 206 if (private == NULL) { 207 /* clear passphrase since it did not work */ 208 clear_pass(); 209 snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ", 210 comment); 211 for (;;) { 212 pass = read_passphrase(msg, RP_ALLOW_STDIN); 213 if (strcmp(pass, "") == 0) { 214 clear_pass(); 215 free(comment); 216 buffer_free(&keyblob); 217 return -1; 218 } 219 private = key_parse_private(&keyblob, filename, pass, 220 &comment); 221 if (private != NULL) 222 break; 223 clear_pass(); 224 snprintf(msg, sizeof msg, 225 "Bad passphrase, try again for %.200s: ", comment); 226 } 227 } 228 buffer_free(&keyblob); 229 230 if (ssh_add_identity_constrained(ac, private, comment, lifetime, 231 confirm)) { 232 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment); 233 ret = 0; 234 if (lifetime != 0) 235 fprintf(stderr, 236 "Lifetime set to %d seconds\n", lifetime); 237 if (confirm != 0) 238 fprintf(stderr, 239 "The user must confirm each use of the key\n"); 240 } else { 241 fprintf(stderr, "Could not add identity: %s\n", filename); 242 } 243 244 /* Skip trying to load the cert if requested */ 245 if (key_only) 246 goto out; 247 248 /* Now try to add the certificate flavour too */ 249 xasprintf(&certpath, "%s-cert.pub", filename); 250 if ((cert = key_load_public(certpath, NULL)) == NULL) 251 goto out; 252 253 if (!key_equal_public(cert, private)) { 254 error("Certificate %s does not match private key %s", 255 certpath, filename); 256 key_free(cert); 257 goto out; 258 } 259 260 /* Graft with private bits */ 261 if (key_to_certified(private, key_cert_is_legacy(cert)) != 0) { 262 error("%s: key_to_certified failed", __func__); 263 key_free(cert); 264 goto out; 265 } 266 key_cert_copy(cert, private); 267 key_free(cert); 268 269 if (!ssh_add_identity_constrained(ac, private, comment, 270 lifetime, confirm)) { 271 error("Certificate %s (%s) add failed", certpath, 272 private->cert->key_id); 273 } 274 fprintf(stderr, "Certificate added: %s (%s)\n", certpath, 275 private->cert->key_id); 276 if (lifetime != 0) 277 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime); 278 if (confirm != 0) 279 fprintf(stderr, "The user must confirm each use of the key\n"); 280 out: 281 if (certpath != NULL) 282 free(certpath); 283 free(comment); 284 key_free(private); 285 286 return ret; 287 } 288 289 static int 290 update_card(AuthenticationConnection *ac, int add, const char *id) 291 { 292 char *pin; 293 int ret = -1; 294 295 pin = read_passphrase("Enter passphrase for PKCS#11: ", RP_ALLOW_STDIN); 296 if (pin == NULL) 297 return -1; 298 299 if (ssh_update_card(ac, add, id, pin, lifetime, confirm)) { 300 fprintf(stderr, "Card %s: %s\n", 301 add ? "added" : "removed", id); 302 ret = 0; 303 } else { 304 fprintf(stderr, "Could not %s card: %s\n", 305 add ? "add" : "remove", id); 306 ret = -1; 307 } 308 free(pin); 309 return ret; 310 } 311 312 static int 313 list_identities(AuthenticationConnection *ac, int do_fp) 314 { 315 Key *key; 316 char *comment, *fp; 317 int had_identities = 0; 318 int version; 319 320 for (version = 1; version <= 2; version++) { 321 for (key = ssh_get_first_identity(ac, &comment, version); 322 key != NULL; 323 key = ssh_get_next_identity(ac, &comment, version)) { 324 had_identities = 1; 325 if (do_fp) { 326 fp = key_fingerprint(key, SSH_FP_MD5, 327 SSH_FP_HEX); 328 printf("%d %s %s (%s)\n", 329 key_size(key), fp, comment, key_type(key)); 330 free(fp); 331 } else { 332 if (!key_write(key, stdout)) 333 fprintf(stderr, "key_write failed"); 334 fprintf(stdout, " %s\n", comment); 335 } 336 key_free(key); 337 free(comment); 338 } 339 } 340 if (!had_identities) { 341 printf("The agent has no identities.\n"); 342 return -1; 343 } 344 return 0; 345 } 346 347 static int 348 lock_agent(AuthenticationConnection *ac, int lock) 349 { 350 char prompt[100], *p1, *p2; 351 int passok = 1, ret = -1; 352 353 strlcpy(prompt, "Enter lock password: ", sizeof(prompt)); 354 p1 = read_passphrase(prompt, RP_ALLOW_STDIN); 355 if (lock) { 356 strlcpy(prompt, "Again: ", sizeof prompt); 357 p2 = read_passphrase(prompt, RP_ALLOW_STDIN); 358 if (strcmp(p1, p2) != 0) { 359 fprintf(stderr, "Passwords do not match.\n"); 360 passok = 0; 361 } 362 memset(p2, 0, strlen(p2)); 363 free(p2); 364 } 365 if (passok && ssh_lock_agent(ac, lock, p1)) { 366 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un"); 367 ret = 0; 368 } else 369 fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un"); 370 memset(p1, 0, strlen(p1)); 371 free(p1); 372 return (ret); 373 } 374 375 static int 376 do_file(AuthenticationConnection *ac, int deleting, int key_only, char *file) 377 { 378 if (deleting) { 379 if (delete_file(ac, file, key_only) == -1) 380 return -1; 381 } else { 382 if (add_file(ac, file, key_only) == -1) 383 return -1; 384 } 385 return 0; 386 } 387 388 static void 389 usage(void) 390 { 391 fprintf(stderr, "usage: %s [options] [file ...]\n", __progname); 392 fprintf(stderr, "Options:\n"); 393 fprintf(stderr, " -l List fingerprints of all identities.\n"); 394 fprintf(stderr, " -L List public key parameters of all identities.\n"); 395 fprintf(stderr, " -k Load only keys and not certificates.\n"); 396 fprintf(stderr, " -c Require confirmation to sign using identities\n"); 397 fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n"); 398 fprintf(stderr, " -d Delete identity.\n"); 399 fprintf(stderr, " -D Delete all identities.\n"); 400 fprintf(stderr, " -x Lock agent.\n"); 401 fprintf(stderr, " -X Unlock agent.\n"); 402 fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n"); 403 fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n"); 404 } 405 406 int 407 main(int argc, char **argv) 408 { 409 extern char *optarg; 410 extern int optind; 411 AuthenticationConnection *ac = NULL; 412 char *pkcs11provider = NULL; 413 int i, ch, deleting = 0, ret = 0, key_only = 0; 414 415 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 416 sanitise_stdfd(); 417 418 OpenSSL_add_all_algorithms(); 419 420 /* At first, get a connection to the authentication agent. */ 421 ac = ssh_get_authentication_connection(); 422 if (ac == NULL) { 423 fprintf(stderr, 424 "Could not open a connection to your authentication agent.\n"); 425 exit(2); 426 } 427 while ((ch = getopt(argc, argv, "klLcdDxXe:s:t:")) != -1) { 428 switch (ch) { 429 case 'k': 430 key_only = 1; 431 break; 432 case 'l': 433 case 'L': 434 if (list_identities(ac, ch == 'l' ? 1 : 0) == -1) 435 ret = 1; 436 goto done; 437 case 'x': 438 case 'X': 439 if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1) 440 ret = 1; 441 goto done; 442 case 'c': 443 confirm = 1; 444 break; 445 case 'd': 446 deleting = 1; 447 break; 448 case 'D': 449 if (delete_all(ac) == -1) 450 ret = 1; 451 goto done; 452 case 's': 453 pkcs11provider = optarg; 454 break; 455 case 'e': 456 deleting = 1; 457 pkcs11provider = optarg; 458 break; 459 case 't': 460 if ((lifetime = convtime(optarg)) == -1) { 461 fprintf(stderr, "Invalid lifetime\n"); 462 ret = 1; 463 goto done; 464 } 465 break; 466 default: 467 usage(); 468 ret = 1; 469 goto done; 470 } 471 } 472 argc -= optind; 473 argv += optind; 474 if (pkcs11provider != NULL) { 475 if (update_card(ac, !deleting, pkcs11provider) == -1) 476 ret = 1; 477 goto done; 478 } 479 if (argc == 0) { 480 char buf[MAXPATHLEN]; 481 struct passwd *pw; 482 struct stat st; 483 int count = 0; 484 485 if ((pw = getpwuid(getuid())) == NULL) { 486 fprintf(stderr, "No user found with uid %u\n", 487 (u_int)getuid()); 488 ret = 1; 489 goto done; 490 } 491 492 for (i = 0; default_files[i]; i++) { 493 snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir, 494 default_files[i]); 495 if (stat(buf, &st) < 0) 496 continue; 497 if (do_file(ac, deleting, key_only, buf) == -1) 498 ret = 1; 499 else 500 count++; 501 } 502 if (count == 0) 503 ret = 1; 504 } else { 505 for (i = 0; i < argc; i++) { 506 if (do_file(ac, deleting, key_only, argv[i]) == -1) 507 ret = 1; 508 } 509 } 510 clear_pass(); 511 512 done: 513 ssh_close_authentication_connection(ac); 514 return ret; 515 } 516