crypto/openssh/ssh-add.c

   1 /* $OpenBSD: ssh-add.c,v 1.101 2011/05/04 21:15:29 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)
 143 {
 144         Key *private, *cert;
 145         char *comment = NULL;
 146         char msg[1024], *certpath;
 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
 223         /* Now try to add the certificate flavour too */
 224         xasprintf(&certpath, "%s-cert.pub", filename);
 225         if ((cert = key_load_public(certpath, NULL)) == NULL)
 226                 goto out;
 227
 228         if (!key_equal_public(cert, private)) {
 229                 error("Certificate %s does not match private key %s",
 230                     certpath, filename);
 231                 key_free(cert);
 232                 goto out;
 233         }
 234
 235         /* Graft with private bits */
 236         if (key_to_certified(private, key_cert_is_legacy(cert)) != 0) {
 237                 error("%s: key_to_certified failed", __func__);
 238                 key_free(cert);
 239                 goto out;
 240         }
 241         key_cert_copy(cert, private);
 242         key_free(cert);
 243
 244         if (!ssh_add_identity_constrained(ac, private, comment,
 245             lifetime, confirm)) {
 246                 error("Certificate %s (%s) add failed", certpath,
 247                     private->cert->key_id);
 248         }
 249         fprintf(stderr, "Certificate added: %s (%s)\n", certpath,
 250             private->cert->key_id);
 251         if (lifetime != 0)
 252                 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime);
 253         if (confirm != 0)
 254                 fprintf(stderr, "The user must confirm each use of the key\n");
 255  out:
 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, char *file)
 351 {
 352         if (deleting) {
 353                 if (delete_file(ac, file) == -1)
 354                         return -1;
 355         } else {
 356                 if (add_file(ac, file) == -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, "  -d          Delete identity.\n");
 370         fprintf(stderr, "  -D          Delete all identities.\n");
 371         fprintf(stderr, "  -x          Lock agent.\n");
 372         fprintf(stderr, "  -X          Unlock agent.\n");
 373         fprintf(stderr, "  -t life     Set lifetime (in seconds) when adding identities.\n");
 374         fprintf(stderr, "  -c          Require confirmation to sign using identities\n");
 375         fprintf(stderr, "  -s pkcs11   Add keys from PKCS#11 provider.\n");
 376         fprintf(stderr, "  -e pkcs11   Remove keys provided by PKCS#11 provider.\n");
 377 }
 378
 379 int
 380 main(int argc, char **argv)
 381 {
 382         extern char *optarg;
 383         extern int optind;
 384         AuthenticationConnection *ac = NULL;
 385         char *pkcs11provider = NULL;
 386         int i, ch, deleting = 0, ret = 0;
 387
 388         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 389         sanitise_stdfd();
 390
 391         __progname = ssh_get_progname(argv[0]);
 392         seed_rng();
 393
 394         OpenSSL_add_all_algorithms();
 395
 396         /* At first, get a connection to the authentication agent. */
 397         ac = ssh_get_authentication_connection();
 398         if (ac == NULL) {
 399                 fprintf(stderr,
 400                     "Could not open a connection to your authentication agent.\n");
 401                 exit(2);
 402         }
 403         while ((ch = getopt(argc, argv, "lLcdDxXe:s:t:")) != -1) {
 404                 switch (ch) {
 405                 case 'l':
 406                 case 'L':
 407                         if (list_identities(ac, ch == 'l' ? 1 : 0) == -1)
 408                                 ret = 1;
 409                         goto done;
 410                 case 'x':
 411                 case 'X':
 412                         if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1)
 413                                 ret = 1;
 414                         goto done;
 415                 case 'c':
 416                         confirm = 1;
 417                         break;
 418                 case 'd':
 419                         deleting = 1;
 420                         break;
 421                 case 'D':
 422                         if (delete_all(ac) == -1)
 423                                 ret = 1;
 424                         goto done;
 425                 case 's':
 426                         pkcs11provider = optarg;
 427                         break;
 428                 case 'e':
 429                         deleting = 1;
 430                         pkcs11provider = optarg;
 431                         break;
 432                 case 't':
 433                         if ((lifetime = convtime(optarg)) == -1) {
 434                                 fprintf(stderr, "Invalid lifetime\n");
 435                                 ret = 1;
 436                                 goto done;
 437                         }
 438                         break;
 439                 default:
 440                         usage();
 441                         ret = 1;
 442                         goto done;
 443                 }
 444         }
 445         argc -= optind;
 446         argv += optind;
 447         if (pkcs11provider != NULL) {
 448                 if (update_card(ac, !deleting, pkcs11provider) == -1)
 449                         ret = 1;
 450                 goto done;
 451         }
 452         if (argc == 0) {
 453                 char buf[MAXPATHLEN];
 454                 struct passwd *pw;
 455                 struct stat st;
 456                 int count = 0;
 457
 458                 if ((pw = getpwuid(getuid())) == NULL) {
 459                         fprintf(stderr, "No user found with uid %u\n",
 460                             (u_int)getuid());
 461                         ret = 1;
 462                         goto done;
 463                 }
 464
 465                 for (i = 0; default_files[i]; i++) {
 466                         snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
 467                             default_files[i]);
 468                         if (stat(buf, &st) < 0)
 469                                 continue;
 470                         if (do_file(ac, deleting, buf) == -1)
 471                                 ret = 1;
 472                         else
 473                                 count++;
 474                 }
 475                 if (count == 0)
 476                         ret = 1;
 477         } else {
 478                 for (i = 0; i < argc; i++) {
 479                         if (do_file(ac, deleting, argv[i]) == -1)
 480                                 ret = 1;
 481                 }
 482         }
 483         clear_pass();
 484
 485 done:
 486         ssh_close_authentication_connection(ac);
 487         return ret;
 488 }