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 #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
 149         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         perms_ok = key_perm_ok(fd, filename);
 159         close(fd);
 160         if (!perms_ok)
 161                 return -1;
 162
 163         /* At first, try empty passphrase */
 164         private = key_load_private(filename, "", &comment);
 165         if (comment == NULL)
 166                 comment = xstrdup(filename);
 167         /* try last */
 168         if (private == NULL && pass != NULL)
 169                 private = key_load_private(filename, pass, NULL);
 170         if (private == NULL) {
 171                 /* clear passphrase since it did not work */
 172                 clear_pass();
 173                 snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ",
 174                     comment);
 175                 for (;;) {
 176                         pass = read_passphrase(msg, RP_ALLOW_STDIN);
 177                         if (strcmp(pass, "") == 0) {
 178                                 clear_pass();
 179                                 xfree(comment);
 180                                 return -1;
 181                         }
 182                         private = key_load_private(filename, pass, &comment);
 183                         if (private != NULL)
 184                                 break;
 185                         clear_pass();
 186                         snprintf(msg, sizeof msg,
 187                             "Bad passphrase, try again for %.200s: ", comment);
 188                 }
 189         }
 190
 191         if (ssh_add_identity_constrained(ac, private, comment, lifetime,
 192             confirm)) {
 193                 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
 194                 ret = 0;
 195                 if (lifetime != 0)
 196                         fprintf(stderr,
 197                             "Lifetime set to %d seconds\n", lifetime);
 198                 if (confirm != 0)
 199                         fprintf(stderr,
 200                             "The user must confirm each use of the key\n");
 201         } else {
 202                 fprintf(stderr, "Could not add identity: %s\n", filename);
 203         }
 204
 205
 206         /* Now try to add the certificate flavour too */
 207         xasprintf(&certpath, "%s-cert.pub", filename);
 208         if ((cert = key_load_public(certpath, NULL)) == NULL)
 209                 goto out;
 210
 211         if (!key_equal_public(cert, private)) {
 212                 error("Certificate %s does not match private key %s",
 213                     certpath, filename);
 214                 key_free(cert);
 215                 goto out;
 216         }
 217
 218         /* Graft with private bits */
 219         if (key_to_certified(private, key_cert_is_legacy(cert)) != 0) {
 220                 error("%s: key_to_certified failed", __func__);
 221                 key_free(cert);
 222                 goto out;
 223         }
 224         key_cert_copy(cert, private);
 225         key_free(cert);
 226
 227         if (!ssh_add_identity_constrained(ac, private, comment,
 228             lifetime, confirm)) {
 229                 error("Certificate %s (%s) add failed", certpath,
 230                     private->cert->key_id);
 231         }
 232         fprintf(stderr, "Certificate added: %s (%s)\n", certpath,
 233             private->cert->key_id);
 234         if (lifetime != 0)
 235                 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime);
 236         if (confirm != 0)
 237                 fprintf(stderr, "The user must confirm each use of the key\n");
 238  out:
 239         xfree(certpath);
 240         xfree(comment);
 241         key_free(private);
 242
 243         return ret;
 244 }
 245
 246 static int
 247 update_card(AuthenticationConnection *ac, int add, const char *id)
 248 {
 249         char *pin;
 250         int ret = -1;
 251
 252         pin = read_passphrase("Enter passphrase for PKCS#11: ", RP_ALLOW_STDIN);
 253         if (pin == NULL)
 254                 return -1;
 255
 256         if (ssh_update_card(ac, add, id, pin, lifetime, confirm)) {
 257                 fprintf(stderr, "Card %s: %s\n",
 258                     add ? "added" : "removed", id);
 259                 ret = 0;
 260         } else {
 261                 fprintf(stderr, "Could not %s card: %s\n",
 262                     add ? "add" : "remove", id);
 263                 ret = -1;
 264         }
 265         xfree(pin);
 266         return ret;
 267 }
 268
 269 static int
 270 list_identities(AuthenticationConnection *ac, int do_fp)
 271 {
 272         Key *key;
 273         char *comment, *fp;
 274         int had_identities = 0;
 275         int version;
 276
 277         for (version = 1; version <= 2; version++) {
 278                 for (key = ssh_get_first_identity(ac, &comment, version);
 279                     key != NULL;
 280                     key = ssh_get_next_identity(ac, &comment, version)) {
 281                         had_identities = 1;
 282                         if (do_fp) {
 283                                 fp = key_fingerprint(key, SSH_FP_MD5,
 284                                     SSH_FP_HEX);
 285                                 printf("%d %s %s (%s)\n",
 286                                     key_size(key), fp, comment, key_type(key));
 287                                 xfree(fp);
 288                         } else {
 289                                 if (!key_write(key, stdout))
 290                                         fprintf(stderr, "key_write failed");
 291                                 fprintf(stdout, " %s\n", comment);
 292                         }
 293                         key_free(key);
 294                         xfree(comment);
 295                 }
 296         }
 297         if (!had_identities) {
 298                 printf("The agent has no identities.\n");
 299                 return -1;
 300         }
 301         return 0;
 302 }
 303
 304 static int
 305 lock_agent(AuthenticationConnection *ac, int lock)
 306 {
 307         char prompt[100], *p1, *p2;
 308         int passok = 1, ret = -1;
 309
 310         strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
 311         p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
 312         if (lock) {
 313                 strlcpy(prompt, "Again: ", sizeof prompt);
 314                 p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
 315                 if (strcmp(p1, p2) != 0) {
 316                         fprintf(stderr, "Passwords do not match.\n");
 317                         passok = 0;
 318                 }
 319                 memset(p2, 0, strlen(p2));
 320                 xfree(p2);
 321         }
 322         if (passok && ssh_lock_agent(ac, lock, p1)) {
 323                 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
 324                 ret = 0;
 325         } else
 326                 fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un");
 327         memset(p1, 0, strlen(p1));
 328         xfree(p1);
 329         return (ret);
 330 }
 331
 332 static int
 333 do_file(AuthenticationConnection *ac, int deleting, char *file)
 334 {
 335         if (deleting) {
 336                 if (delete_file(ac, file) == -1)
 337                         return -1;
 338         } else {
 339                 if (add_file(ac, file) == -1)
 340                         return -1;
 341         }
 342         return 0;
 343 }
 344
 345 static void
 346 usage(void)
 347 {
 348         fprintf(stderr, "usage: %s [options] [file ...]\n", __progname);
 349         fprintf(stderr, "Options:\n");
 350         fprintf(stderr, "  -l          List fingerprints of all identities.\n");
 351         fprintf(stderr, "  -L          List public key parameters of all identities.\n");
 352         fprintf(stderr, "  -d          Delete identity.\n");
 353         fprintf(stderr, "  -D          Delete all identities.\n");
 354         fprintf(stderr, "  -x          Lock agent.\n");
 355         fprintf(stderr, "  -X          Unlock agent.\n");
 356         fprintf(stderr, "  -t life     Set lifetime (in seconds) when adding identities.\n");
 357         fprintf(stderr, "  -c          Require confirmation to sign using identities\n");
 358         fprintf(stderr, "  -s pkcs11   Add keys from PKCS#11 provider.\n");
 359         fprintf(stderr, "  -e pkcs11   Remove keys provided by PKCS#11 provider.\n");
 360 }
 361
 362 int
 363 main(int argc, char **argv)
 364 {
 365         extern char *optarg;
 366         extern int optind;
 367         AuthenticationConnection *ac = NULL;
 368         char *pkcs11provider = NULL;
 369         int i, ch, deleting = 0, ret = 0;
 370
 371         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 372         sanitise_stdfd();
 373
 374         __progname = ssh_get_progname(argv[0]);
 375         init_rng();
 376         seed_rng();
 377
 378         OpenSSL_add_all_algorithms();
 379
 380         /* At first, get a connection to the authentication agent. */
 381         ac = ssh_get_authentication_connection();
 382         if (ac == NULL) {
 383                 fprintf(stderr,
 384                     "Could not open a connection to your authentication agent.\n");
 385                 exit(2);
 386         }
 387         while ((ch = getopt(argc, argv, "lLcdDxXe:s:t:")) != -1) {
 388                 switch (ch) {
 389                 case 'l':
 390                 case 'L':
 391                         if (list_identities(ac, ch == 'l' ? 1 : 0) == -1)
 392                                 ret = 1;
 393                         goto done;
 394                 case 'x':
 395                 case 'X':
 396                         if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1)
 397                                 ret = 1;
 398                         goto done;
 399                 case 'c':
 400                         confirm = 1;
 401                         break;
 402                 case 'd':
 403                         deleting = 1;
 404                         break;
 405                 case 'D':
 406                         if (delete_all(ac) == -1)
 407                                 ret = 1;
 408                         goto done;
 409                 case 's':
 410                         pkcs11provider = optarg;
 411                         break;
 412                 case 'e':
 413                         deleting = 1;
 414                         pkcs11provider = optarg;
 415                         break;
 416                 case 't':
 417                         if ((lifetime = convtime(optarg)) == -1) {
 418                                 fprintf(stderr, "Invalid lifetime\n");
 419                                 ret = 1;
 420                                 goto done;
 421                         }
 422                         break;
 423                 default:
 424                         usage();
 425                         ret = 1;
 426                         goto done;
 427                 }
 428         }
 429         argc -= optind;
 430         argv += optind;
 431         if (pkcs11provider != NULL) {
 432                 if (update_card(ac, !deleting, pkcs11provider) == -1)
 433                         ret = 1;
 434                 goto done;
 435         }
 436         if (argc == 0) {
 437                 char buf[MAXPATHLEN];
 438                 struct passwd *pw;
 439                 struct stat st;
 440                 int count = 0;
 441
 442                 if ((pw = getpwuid(getuid())) == NULL) {
 443                         fprintf(stderr, "No user found with uid %u\n",
 444                             (u_int)getuid());
 445                         ret = 1;
 446                         goto done;
 447                 }
 448
 449                 for (i = 0; default_files[i]; i++) {
 450                         snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
 451                             default_files[i]);
 452                         if (stat(buf, &st) < 0)
 453                                 continue;
 454                         if (do_file(ac, deleting, buf) == -1)
 455                                 ret = 1;
 456                         else
 457                                 count++;
 458                 }
 459                 if (count == 0)
 460                         ret = 1;
 461         } else {
 462                 for (i = 0; i < argc; i++) {
 463                         if (do_file(ac, deleting, argv[i]) == -1)
 464                                 ret = 1;
 465                 }
 466         }
 467         clear_pass();
 468
 469 done:
 470         ssh_close_authentication_connection(ac);
 471         return ret;
 472 }