ssh-add.c revision 262566
1/* $OpenBSD: ssh-add.c,v 1.108 2013/12/19 00:10:30 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 */ 67extern char *__progname; 68 69/* Default files to add */ 70static 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_ID_ED25519, 77 _PATH_SSH_CLIENT_IDENTITY, 78 NULL 79}; 80 81/* Default lifetime (0 == forever) */ 82static int lifetime = 0; 83 84/* User has to confirm key use */ 85static int confirm = 0; 86 87/* we keep a cache of one passphrases */ 88static char *pass = NULL; 89static void 90clear_pass(void) 91{ 92 if (pass) { 93 memset(pass, 0, strlen(pass)); 94 free(pass); 95 pass = NULL; 96 } 97} 98 99static int 100delete_file(AuthenticationConnection *ac, const char *filename, int key_only) 101{ 102 Key *public = NULL, *cert = NULL; 103 char *certpath = NULL, *comment = NULL; 104 int ret = -1; 105 106 public = key_load_public(filename, &comment); 107 if (public == NULL) { 108 printf("Bad key file %s\n", filename); 109 return -1; 110 } 111 if (ssh_remove_identity(ac, public)) { 112 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment); 113 ret = 0; 114 } else 115 fprintf(stderr, "Could not remove identity: %s\n", filename); 116 117 if (key_only) 118 goto out; 119 120 /* Now try to delete the corresponding certificate too */ 121 free(comment); 122 comment = NULL; 123 xasprintf(&certpath, "%s-cert.pub", filename); 124 if ((cert = key_load_public(certpath, &comment)) == NULL) 125 goto out; 126 if (!key_equal_public(cert, public)) 127 fatal("Certificate %s does not match private key %s", 128 certpath, filename); 129 130 if (ssh_remove_identity(ac, cert)) { 131 fprintf(stderr, "Identity removed: %s (%s)\n", certpath, 132 comment); 133 ret = 0; 134 } else 135 fprintf(stderr, "Could not remove identity: %s\n", certpath); 136 137 out: 138 if (cert != NULL) 139 key_free(cert); 140 if (public != NULL) 141 key_free(public); 142 free(certpath); 143 free(comment); 144 145 return ret; 146} 147 148/* Send a request to remove all identities. */ 149static int 150delete_all(AuthenticationConnection *ac) 151{ 152 int ret = -1; 153 154 if (ssh_remove_all_identities(ac, 1)) 155 ret = 0; 156 /* ignore error-code for ssh2 */ 157 ssh_remove_all_identities(ac, 2); 158 159 if (ret == 0) 160 fprintf(stderr, "All identities removed.\n"); 161 else 162 fprintf(stderr, "Failed to remove all identities.\n"); 163 164 return ret; 165} 166 167static int 168add_file(AuthenticationConnection *ac, const char *filename, int key_only) 169{ 170 Key *private, *cert; 171 char *comment = NULL; 172 char msg[1024], *certpath = NULL; 173 int fd, perms_ok, ret = -1; 174 Buffer keyblob; 175 176 if (strcmp(filename, "-") == 0) { 177 fd = STDIN_FILENO; 178 filename = "(stdin)"; 179 } else if ((fd = open(filename, O_RDONLY)) < 0) { 180 perror(filename); 181 return -1; 182 } 183 184 /* 185 * Since we'll try to load a keyfile multiple times, permission errors 186 * will occur multiple times, so check perms first and bail if wrong. 187 */ 188 if (fd != STDIN_FILENO) { 189 perms_ok = key_perm_ok(fd, filename); 190 if (!perms_ok) { 191 close(fd); 192 return -1; 193 } 194 } 195 buffer_init(&keyblob); 196 if (!key_load_file(fd, filename, &keyblob)) { 197 buffer_free(&keyblob); 198 close(fd); 199 return -1; 200 } 201 close(fd); 202 203 /* At first, try empty passphrase */ 204 private = key_parse_private(&keyblob, filename, "", &comment); 205 if (comment == NULL) 206 comment = xstrdup(filename); 207 /* try last */ 208 if (private == NULL && pass != NULL) 209 private = key_parse_private(&keyblob, filename, pass, NULL); 210 if (private == NULL) { 211 /* clear passphrase since it did not work */ 212 clear_pass(); 213 snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ", 214 comment); 215 for (;;) { 216 pass = read_passphrase(msg, RP_ALLOW_STDIN); 217 if (strcmp(pass, "") == 0) { 218 clear_pass(); 219 free(comment); 220 buffer_free(&keyblob); 221 return -1; 222 } 223 private = key_parse_private(&keyblob, filename, pass, 224 &comment); 225 if (private != NULL) 226 break; 227 clear_pass(); 228 snprintf(msg, sizeof msg, 229 "Bad passphrase, try again for %.200s: ", comment); 230 } 231 } 232 buffer_free(&keyblob); 233 234 if (ssh_add_identity_constrained(ac, private, comment, lifetime, 235 confirm)) { 236 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment); 237 ret = 0; 238 if (lifetime != 0) 239 fprintf(stderr, 240 "Lifetime set to %d seconds\n", lifetime); 241 if (confirm != 0) 242 fprintf(stderr, 243 "The user must confirm each use of the key\n"); 244 } else { 245 fprintf(stderr, "Could not add identity: %s\n", filename); 246 } 247 248 /* Skip trying to load the cert if requested */ 249 if (key_only) 250 goto out; 251 252 /* Now try to add the certificate flavour too */ 253 xasprintf(&certpath, "%s-cert.pub", filename); 254 if ((cert = key_load_public(certpath, NULL)) == NULL) 255 goto out; 256 257 if (!key_equal_public(cert, private)) { 258 error("Certificate %s does not match private key %s", 259 certpath, filename); 260 key_free(cert); 261 goto out; 262 } 263 264 /* Graft with private bits */ 265 if (key_to_certified(private, key_cert_is_legacy(cert)) != 0) { 266 error("%s: key_to_certified failed", __func__); 267 key_free(cert); 268 goto out; 269 } 270 key_cert_copy(cert, private); 271 key_free(cert); 272 273 if (!ssh_add_identity_constrained(ac, private, comment, 274 lifetime, confirm)) { 275 error("Certificate %s (%s) add failed", certpath, 276 private->cert->key_id); 277 } 278 fprintf(stderr, "Certificate added: %s (%s)\n", certpath, 279 private->cert->key_id); 280 if (lifetime != 0) 281 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime); 282 if (confirm != 0) 283 fprintf(stderr, "The user must confirm each use of the key\n"); 284 out: 285 if (certpath != NULL) 286 free(certpath); 287 free(comment); 288 key_free(private); 289 290 return ret; 291} 292 293static int 294update_card(AuthenticationConnection *ac, int add, const char *id) 295{ 296 char *pin = NULL; 297 int ret = -1; 298 299 if (add) { 300 if ((pin = read_passphrase("Enter passphrase for PKCS#11: ", 301 RP_ALLOW_STDIN)) == NULL) 302 return -1; 303 } 304 305 if (ssh_update_card(ac, add, id, pin == NULL ? "" : pin, 306 lifetime, confirm)) { 307 fprintf(stderr, "Card %s: %s\n", 308 add ? "added" : "removed", id); 309 ret = 0; 310 } else { 311 fprintf(stderr, "Could not %s card: %s\n", 312 add ? "add" : "remove", id); 313 ret = -1; 314 } 315 free(pin); 316 return ret; 317} 318 319static int 320list_identities(AuthenticationConnection *ac, int do_fp) 321{ 322 Key *key; 323 char *comment, *fp; 324 int had_identities = 0; 325 int version; 326 327 for (version = 1; version <= 2; version++) { 328 for (key = ssh_get_first_identity(ac, &comment, version); 329 key != NULL; 330 key = ssh_get_next_identity(ac, &comment, version)) { 331 had_identities = 1; 332 if (do_fp) { 333 fp = key_fingerprint(key, SSH_FP_MD5, 334 SSH_FP_HEX); 335 printf("%d %s %s (%s)\n", 336 key_size(key), fp, comment, key_type(key)); 337 free(fp); 338 } else { 339 if (!key_write(key, stdout)) 340 fprintf(stderr, "key_write failed"); 341 fprintf(stdout, " %s\n", comment); 342 } 343 key_free(key); 344 free(comment); 345 } 346 } 347 if (!had_identities) { 348 printf("The agent has no identities.\n"); 349 return -1; 350 } 351 return 0; 352} 353 354static int 355lock_agent(AuthenticationConnection *ac, int lock) 356{ 357 char prompt[100], *p1, *p2; 358 int passok = 1, ret = -1; 359 360 strlcpy(prompt, "Enter lock password: ", sizeof(prompt)); 361 p1 = read_passphrase(prompt, RP_ALLOW_STDIN); 362 if (lock) { 363 strlcpy(prompt, "Again: ", sizeof prompt); 364 p2 = read_passphrase(prompt, RP_ALLOW_STDIN); 365 if (strcmp(p1, p2) != 0) { 366 fprintf(stderr, "Passwords do not match.\n"); 367 passok = 0; 368 } 369 memset(p2, 0, strlen(p2)); 370 free(p2); 371 } 372 if (passok && ssh_lock_agent(ac, lock, p1)) { 373 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un"); 374 ret = 0; 375 } else 376 fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un"); 377 memset(p1, 0, strlen(p1)); 378 free(p1); 379 return (ret); 380} 381 382static int 383do_file(AuthenticationConnection *ac, int deleting, int key_only, char *file) 384{ 385 if (deleting) { 386 if (delete_file(ac, file, key_only) == -1) 387 return -1; 388 } else { 389 if (add_file(ac, file, key_only) == -1) 390 return -1; 391 } 392 return 0; 393} 394 395static void 396usage(void) 397{ 398 fprintf(stderr, "usage: %s [options] [file ...]\n", __progname); 399 fprintf(stderr, "Options:\n"); 400 fprintf(stderr, " -l List fingerprints of all identities.\n"); 401 fprintf(stderr, " -L List public key parameters of all identities.\n"); 402 fprintf(stderr, " -k Load only keys and not certificates.\n"); 403 fprintf(stderr, " -c Require confirmation to sign using identities\n"); 404 fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n"); 405 fprintf(stderr, " -d Delete identity.\n"); 406 fprintf(stderr, " -D Delete all identities.\n"); 407 fprintf(stderr, " -x Lock agent.\n"); 408 fprintf(stderr, " -X Unlock agent.\n"); 409 fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n"); 410 fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n"); 411} 412 413int 414main(int argc, char **argv) 415{ 416 extern char *optarg; 417 extern int optind; 418 AuthenticationConnection *ac = NULL; 419 char *pkcs11provider = NULL; 420 int i, ch, deleting = 0, ret = 0, key_only = 0; 421 422 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 423 sanitise_stdfd(); 424 425 __progname = ssh_get_progname(argv[0]); 426 seed_rng(); 427 428 OpenSSL_add_all_algorithms(); 429 430 /* At first, get a connection to the authentication agent. */ 431 ac = ssh_get_authentication_connection(); 432 if (ac == NULL) { 433 fprintf(stderr, 434 "Could not open a connection to your authentication agent.\n"); 435 exit(2); 436 } 437 while ((ch = getopt(argc, argv, "klLcdDxXe:s:t:")) != -1) { 438 switch (ch) { 439 case 'k': 440 key_only = 1; 441 break; 442 case 'l': 443 case 'L': 444 if (list_identities(ac, ch == 'l' ? 1 : 0) == -1) 445 ret = 1; 446 goto done; 447 case 'x': 448 case 'X': 449 if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1) 450 ret = 1; 451 goto done; 452 case 'c': 453 confirm = 1; 454 break; 455 case 'd': 456 deleting = 1; 457 break; 458 case 'D': 459 if (delete_all(ac) == -1) 460 ret = 1; 461 goto done; 462 case 's': 463 pkcs11provider = optarg; 464 break; 465 case 'e': 466 deleting = 1; 467 pkcs11provider = optarg; 468 break; 469 case 't': 470 if ((lifetime = convtime(optarg)) == -1) { 471 fprintf(stderr, "Invalid lifetime\n"); 472 ret = 1; 473 goto done; 474 } 475 break; 476 default: 477 usage(); 478 ret = 1; 479 goto done; 480 } 481 } 482 argc -= optind; 483 argv += optind; 484 if (pkcs11provider != NULL) { 485 if (update_card(ac, !deleting, pkcs11provider) == -1) 486 ret = 1; 487 goto done; 488 } 489 if (argc == 0) { 490 char buf[MAXPATHLEN]; 491 struct passwd *pw; 492 struct stat st; 493 int count = 0; 494 495 if ((pw = getpwuid(getuid())) == NULL) { 496 fprintf(stderr, "No user found with uid %u\n", 497 (u_int)getuid()); 498 ret = 1; 499 goto done; 500 } 501 502 for (i = 0; default_files[i]; i++) { 503 snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir, 504 default_files[i]); 505 if (stat(buf, &st) < 0) 506 continue; 507 if (do_file(ac, deleting, key_only, buf) == -1) 508 ret = 1; 509 else 510 count++; 511 } 512 if (count == 0) 513 ret = 1; 514 } else { 515 for (i = 0; i < argc; i++) { 516 if (do_file(ac, deleting, key_only, argv[i]) == -1) 517 ret = 1; 518 } 519 } 520 clear_pass(); 521 522done: 523 ssh_close_authentication_connection(ac); 524 return ret; 525} 526