ssh-add.c

   1 /* $OpenBSD: ssh-add.c,v 1.100 2010/08/31 12:33:38 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         _PATH_SSH_CLIENT_ID_ECDSA,
  74         _PATH_SSH_CLIENT_IDENTITY,
  75         NULL
  76 };
  77
  78 /* Default lifetime (0 == forever) */
  79 static int lifetime = 0;
  80
  81 /* User has to confirm key use */
  82 static int confirm = 0;
  83
  84 /* we keep a cache of one passphrases */
  85 static char *pass = NULL;
  86 static void
  87 clear_pass(void)
  88 {
  89         if (pass) {
  90                 memset(pass, 0, strlen(pass));
  91                 xfree(pass);
  92                 pass = NULL;
  93         }
  94 }
  95
  96 static int
  97 delete_file(AuthenticationConnection *ac, const char *filename)
  98 {
  99         Key *public;
 100         char *comment = NULL;
 101         int ret = -1;
 102
 103         public = key_load_public(filename, &comment);
 104         if (public == NULL) {
 105                 printf("Bad key file %s\n", filename);
 106                 return -1;
 107         }
 108         if (ssh_remove_identity(ac, public)) {
 109                 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment);
 110                 ret = 0;
 111         } else
 112                 fprintf(stderr, "Could not remove identity: %s\n", filename);
 113
 114         key_free(public);
 115         xfree(comment);
 116
 117         return ret;
 118 }
 119
 120 /* Send a request to remove all identities. */
 121 static int
 122 delete_all(AuthenticationConnection *ac)
 123 {
 124         int ret = -1;
 125
 126         if (ssh_remove_all_identities(ac, 1))
 127                 ret = 0;
 128         /* ignore error-code for ssh2 */
 129         ssh_remove_all_identities(ac, 2);
 130
 131         if (ret == 0)
 132                 fprintf(stderr, "All identities removed.\n");
 133         else
 134                 fprintf(stderr, "Failed to remove all identities.\n");
 135
 136         return ret;
 137 }
 138
 139 static int
 140 add_file(AuthenticationConnection *ac, const char *filename)
 141 {
 142         Key *private, *cert;
 143         char *comment = NULL;
 144         char msg[1024], *certpath;
 145         int fd, perms_ok, ret = -1;
 146
 147         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         perms_ok = key_perm_ok(fd, filename);
 157         close(fd);
 158         if (!perms_ok)
 159                 return -1;
 160
 161         /* At first, try empty passphrase */
 162         private = key_load_private(filename, "", &comment);
 163         if (comment == NULL)
 164                 comment = xstrdup(filename);
 165         /* try last */
 166         if (private == NULL && pass != NULL)
 167                 private = key_load_private(filename, pass, NULL);
 168         if (private == NULL) {
 169                 /* clear passphrase since it did not work */
 170                 clear_pass();
 171                 snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ",
 172                     comment);
 173                 for (;;) {
 174                         pass = read_passphrase(msg, RP_ALLOW_STDIN);
 175                         if (strcmp(pass, "") == 0) {
 176                                 clear_pass();
 177                                 xfree(comment);
 178                                 return -1;
 179                         }
 180                         private = key_load_private(filename, pass, &comment);
 181                         if (private != NULL)
 182                                 break;
 183                         clear_pass();
 184                         snprintf(msg, sizeof msg,
 185                             "Bad passphrase, try again for %.200s: ", comment);
 186                 }
 187         }
 188
 189         if (ssh_add_identity_constrained(ac, private, comment, lifetime,
 190             confirm)) {
 191                 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
 192                 ret = 0;
 193                 if (lifetime != 0)
 194                         fprintf(stderr,
 195                             "Lifetime set to %d seconds\n", lifetime);
 196                 if (confirm != 0)
 197                         fprintf(stderr,
 198                             "The user must confirm each use of the key\n");
 199         } else {
 200                 fprintf(stderr, "Could not add identity: %s\n", filename);
 201         }
 202
 203
 204         /* Now try to add the certificate flavour too */
 205         xasprintf(&certpath, "%s-cert.pub", filename);
 206         if ((cert = key_load_public(certpath, NULL)) == NULL)
 207                 goto out;
 208
 209         if (!key_equal_public(cert, private)) {
 210                 error("Certificate %s does not match private key %s",
 211                     certpath, filename);
 212                 key_free(cert);
 213                 goto out;
 214         }
 215
 216         /* Graft with private bits */
 217         if (key_to_certified(private, key_cert_is_legacy(cert)) != 0) {
 218                 error("%s: key_to_certified failed", __func__);
 219                 key_free(cert);
 220                 goto out;
 221         }
 222         key_cert_copy(cert, private);
 223         key_free(cert);
 224
 225         if (!ssh_add_identity_constrained(ac, private, comment,
 226             lifetime, confirm)) {
 227                 error("Certificate %s (%s) add failed", certpath,
 228                     private->cert->key_id);
 229         }
 230         fprintf(stderr, "Certificate added: %s (%s)\n", certpath,
 231             private->cert->key_id);
 232         if (lifetime != 0)
 233                 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime);
 234         if (confirm != 0)
 235                 fprintf(stderr, "The user must confirm each use of the key\n");
 236  out:
 237         xfree(certpath);
 238         xfree(comment);
 239         key_free(private);
 240
 241         return ret;
 242 }
 243
 244 static int
 245 update_card(AuthenticationConnection *ac, int add, const char *id)
 246 {
 247         char *pin;
 248         int ret = -1;
 249
 250         pin = read_passphrase("Enter passphrase for PKCS#11: ", RP_ALLOW_STDIN);
 251         if (pin == NULL)
 252                 return -1;
 253
 254         if (ssh_update_card(ac, add, id, pin, lifetime, confirm)) {
 255                 fprintf(stderr, "Card %s: %s\n",
 256                     add ? "added" : "removed", id);
 257                 ret = 0;
 258         } else {
 259                 fprintf(stderr, "Could not %s card: %s\n",
 260                     add ? "add" : "remove", id);
 261                 ret = -1;
 262         }
 263         xfree(pin);
 264         return ret;
 265 }
 266
 267 static int
 268 list_identities(AuthenticationConnection *ac, int do_fp)
 269 {
 270         Key *key;
 271         char *comment, *fp;
 272         int had_identities = 0;
 273         int version;
 274
 275         for (version = 1; version <= 2; version++) {
 276                 for (key = ssh_get_first_identity(ac, &comment, version);
 277                     key != NULL;
 278                     key = ssh_get_next_identity(ac, &comment, version)) {
 279                         had_identities = 1;
 280                         if (do_fp) {
 281                                 fp = key_fingerprint(key, SSH_FP_MD5,
 282                                     SSH_FP_HEX);
 283                                 printf("%d %s %s (%s)\n",
 284                                     key_size(key), fp, comment, key_type(key));
 285                                 xfree(fp);
 286                         } else {
 287                                 if (!key_write(key, stdout))
 288                                         fprintf(stderr, "key_write failed");
 289                                 fprintf(stdout, " %s\n", comment);
 290                         }
 291                         key_free(key);
 292                         xfree(comment);
 293                 }
 294         }
 295         if (!had_identities) {
 296                 printf("The agent has no identities.\n");
 297                 return -1;
 298         }
 299         return 0;
 300 }
 301
 302 static int
 303 lock_agent(AuthenticationConnection *ac, int lock)
 304 {
 305         char prompt[100], *p1, *p2;
 306         int passok = 1, ret = -1;
 307
 308         strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
 309         p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
 310         if (lock) {
 311                 strlcpy(prompt, "Again: ", sizeof prompt);
 312                 p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
 313                 if (strcmp(p1, p2) != 0) {
 314                         fprintf(stderr, "Passwords do not match.\n");
 315                         passok = 0;
 316                 }
 317                 memset(p2, 0, strlen(p2));
 318                 xfree(p2);
 319         }
 320         if (passok && ssh_lock_agent(ac, lock, p1)) {
 321                 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
 322                 ret = 0;
 323         } else
 324                 fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un");
 325         memset(p1, 0, strlen(p1));
 326         xfree(p1);
 327         return (ret);
 328 }
 329
 330 static int
 331 do_file(AuthenticationConnection *ac, int deleting, char *file)
 332 {
 333         if (deleting) {
 334                 if (delete_file(ac, file) == -1)
 335                         return -1;
 336         } else {
 337                 if (add_file(ac, file) == -1)
 338                         return -1;
 339         }
 340         return 0;
 341 }
 342
 343 static void
 344 usage(void)
 345 {
 346         fprintf(stderr, "usage: %s [options] [file ...]\n", __progname);
 347         fprintf(stderr, "Options:\n");
 348         fprintf(stderr, "  -l          List fingerprints of all identities.\n");
 349         fprintf(stderr, "  -L          List public key parameters of all identities.\n");
 350         fprintf(stderr, "  -d          Delete identity.\n");
 351         fprintf(stderr, "  -D          Delete all identities.\n");
 352         fprintf(stderr, "  -x          Lock agent.\n");
 353         fprintf(stderr, "  -X          Unlock agent.\n");
 354         fprintf(stderr, "  -t life     Set lifetime (in seconds) when adding identities.\n");
 355         fprintf(stderr, "  -c          Require confirmation to sign using identities\n");
 356         fprintf(stderr, "  -s pkcs11   Add keys from PKCS#11 provider.\n");
 357         fprintf(stderr, "  -e pkcs11   Remove keys provided by PKCS#11 provider.\n");
 358 }
 359
 360 int
 361 main(int argc, char **argv)
 362 {
 363         extern char *optarg;
 364         extern int optind;
 365         AuthenticationConnection *ac = NULL;
 366         char *pkcs11provider = NULL;
 367         int i, ch, deleting = 0, ret = 0;
 368
 369         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 370         sanitise_stdfd();
 371
 372         __progname = ssh_get_progname(argv[0]);
 373         init_rng();
 374         seed_rng();
 375
 376         OpenSSL_add_all_algorithms();
 377
 378         /* At first, get a connection to the authentication agent. */
 379         ac = ssh_get_authentication_connection();
 380         if (ac == NULL) {
 381                 fprintf(stderr,
 382                     "Could not open a connection to your authentication agent.\n");
 383                 exit(2);
 384         }
 385         while ((ch = getopt(argc, argv, "lLcdDxXe:s:t:")) != -1) {
 386                 switch (ch) {
 387                 case 'l':
 388                 case 'L':
 389                         if (list_identities(ac, ch == 'l' ? 1 : 0) == -1)
 390                                 ret = 1;
 391                         goto done;
 392                 case 'x':
 393                 case 'X':
 394                         if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1)
 395                                 ret = 1;
 396                         goto done;
 397                 case 'c':
 398                         confirm = 1;
 399                         break;
 400                 case 'd':
 401                         deleting = 1;
 402                         break;
 403                 case 'D':
 404                         if (delete_all(ac) == -1)
 405                                 ret = 1;
 406                         goto done;
 407                 case 's':
 408                         pkcs11provider = optarg;
 409                         break;
 410                 case 'e':
 411                         deleting = 1;
 412                         pkcs11provider = optarg;
 413                         break;
 414                 case 't':
 415                         if ((lifetime = convtime(optarg)) == -1) {
 416                                 fprintf(stderr, "Invalid lifetime\n");
 417                                 ret = 1;
 418                                 goto done;
 419                         }
 420                         break;
 421                 default:
 422                         usage();
 423                         ret = 1;
 424                         goto done;
 425                 }
 426         }
 427         argc -= optind;
 428         argv += optind;
 429         if (pkcs11provider != NULL) {
 430                 if (update_card(ac, !deleting, pkcs11provider) == -1)
 431                         ret = 1;
 432                 goto done;
 433         }
 434         if (argc == 0) {
 435                 char buf[MAXPATHLEN];
 436                 struct passwd *pw;
 437                 struct stat st;
 438                 int count = 0;
 439
 440                 if ((pw = getpwuid(getuid())) == NULL) {
 441                         fprintf(stderr, "No user found with uid %u\n",
 442                             (u_int)getuid());
 443                         ret = 1;
 444                         goto done;
 445                 }
 446
 447                 for (i = 0; default_files[i]; i++) {
 448                         snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
 449                             default_files[i]);
 450                         if (stat(buf, &st) < 0)
 451                                 continue;
 452                         if (do_file(ac, deleting, buf) == -1)
 453                                 ret = 1;
 454                         else
 455                                 count++;
 456                 }
 457                 if (count == 0)
 458                         ret = 1;
 459         } else {
 460                 for (i = 0; i < argc; i++) {
 461                         if (do_file(ac, deleting, argv[i]) == -1)
 462                                 ret = 1;
 463                 }
 464         }
 465         clear_pass();
 466
 467 done:
 468         ssh_close_authentication_connection(ac);
 469         return ret;
 470 }