ssh-add.c

   1 /*
   2  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   3  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   4  *                    All rights reserved
   5  * Adds an identity to the authentication server, or removes an identity.
   6  *
   7  * As far as I am concerned, the code I have written for this software
   8  * can be used freely for any purpose.  Any derived versions of this
   9  * software must be clearly marked as such, and if the derived work is
  10  * incompatible with the protocol description in the RFC file, it must be
  11  * called by a name other than "ssh" or "Secure Shell".
  12  *
  13  * SSH2 implementation,
  14  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  15  *
  16  * Redistribution and use in source and binary forms, with or without
  17  * modification, are permitted provided that the following conditions
  18  * are met:
  19  * 1. Redistributions of source code must retain the above copyright
  20  *    notice, this list of conditions and the following disclaimer.
  21  * 2. Redistributions in binary form must reproduce the above copyright
  22  *    notice, this list of conditions and the following disclaimer in the
  23  *    documentation and/or other materials provided with the distribution.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  26  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  27  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  28  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  29  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  30  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  31  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  34  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  */
  36
  37 #include "includes.h"
  38 RCSID("$OpenBSD: ssh-add.c,v 1.71 2005/03/10 22:01:06 deraadt Exp $");
  39
  40 #include <openssl/evp.h>
  41
  42 #include "ssh.h"
  43 #include "rsa.h"
  44 #include "log.h"
  45 #include "xmalloc.h"
  46 #include "key.h"
  47 #include "authfd.h"
  48 #include "authfile.h"
  49 #include "pathnames.h"
  50 #include "misc.h"
  51
  52 /* argv0 */
  53 extern char *__progname;
  54
  55 /* Default files to add */
  56 static char *default_files[] = {
  57         _PATH_SSH_CLIENT_ID_RSA,
  58         _PATH_SSH_CLIENT_ID_DSA,
  59         _PATH_SSH_CLIENT_IDENTITY,
  60         NULL
  61 };
  62
  63 /* Default lifetime (0 == forever) */
  64 static int lifetime = 0;
  65
  66 /* User has to confirm key use */
  67 static int confirm = 0;
  68
  69 /* we keep a cache of one passphrases */
  70 static char *pass = NULL;
  71 static void
  72 clear_pass(void)
  73 {
  74         if (pass) {
  75                 memset(pass, 0, strlen(pass));
  76                 xfree(pass);
  77                 pass = NULL;
  78         }
  79 }
  80
  81 static int
  82 delete_file(AuthenticationConnection *ac, const char *filename)
  83 {
  84         Key *public;
  85         char *comment = NULL;
  86         int ret = -1;
  87
  88         public = key_load_public(filename, &comment);
  89         if (public == NULL) {
  90                 printf("Bad key file %s\n", filename);
  91                 return -1;
  92         }
  93         if (ssh_remove_identity(ac, public)) {
  94                 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment);
  95                 ret = 0;
  96         } else
  97                 fprintf(stderr, "Could not remove identity: %s\n", filename);
  98
  99         key_free(public);
 100         xfree(comment);
 101
 102         return ret;
 103 }
 104
 105 /* Send a request to remove all identities. */
 106 static int
 107 delete_all(AuthenticationConnection *ac)
 108 {
 109         int ret = -1;
 110
 111         if (ssh_remove_all_identities(ac, 1))
 112                 ret = 0;
 113         /* ignore error-code for ssh2 */
 114         ssh_remove_all_identities(ac, 2);
 115
 116         if (ret == 0)
 117                 fprintf(stderr, "All identities removed.\n");
 118         else
 119                 fprintf(stderr, "Failed to remove all identities.\n");
 120
 121         return ret;
 122 }
 123
 124 static int
 125 add_file(AuthenticationConnection *ac, const char *filename)
 126 {
 127         struct stat st;
 128         Key *private;
 129         char *comment = NULL;
 130         char msg[1024];
 131         int ret = -1;
 132
 133         if (stat(filename, &st) < 0) {
 134                 perror(filename);
 135                 return -1;
 136         }
 137         /* At first, try empty passphrase */
 138         private = key_load_private(filename, "", &comment);
 139         if (comment == NULL)
 140                 comment = xstrdup(filename);
 141         /* try last */
 142         if (private == NULL && pass != NULL)
 143                 private = key_load_private(filename, pass, NULL);
 144         if (private == NULL) {
 145                 /* clear passphrase since it did not work */
 146                 clear_pass();
 147                 snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ",
 148                    comment);
 149                 for (;;) {
 150                         pass = read_passphrase(msg, RP_ALLOW_STDIN);
 151                         if (strcmp(pass, "") == 0) {
 152                                 clear_pass();
 153                                 xfree(comment);
 154                                 return -1;
 155                         }
 156                         private = key_load_private(filename, pass, &comment);
 157                         if (private != NULL)
 158                                 break;
 159                         clear_pass();
 160                         snprintf(msg, sizeof msg,
 161                             "Bad passphrase, try again for %.200s: ", comment);
 162                 }
 163         }
 164
 165         if (ssh_add_identity_constrained(ac, private, comment, lifetime,
 166             confirm)) {
 167                 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
 168                 ret = 0;
 169                 if (lifetime != 0)
 170                         fprintf(stderr,
 171                             "Lifetime set to %d seconds\n", lifetime);
 172                 if (confirm != 0)
 173                         fprintf(stderr,
 174                             "The user has to confirm each use of the key\n");
 175         } else if (ssh_add_identity(ac, private, comment)) {
 176                 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
 177                 ret = 0;
 178         } else {
 179                 fprintf(stderr, "Could not add identity: %s\n", filename);
 180         }
 181
 182         xfree(comment);
 183         key_free(private);
 184
 185         return ret;
 186 }
 187
 188 static int
 189 update_card(AuthenticationConnection *ac, int add, const char *id)
 190 {
 191         char *pin;
 192         int ret = -1;
 193
 194         pin = read_passphrase("Enter passphrase for smartcard: ", RP_ALLOW_STDIN);
 195         if (pin == NULL)
 196                 return -1;
 197
 198         if (ssh_update_card(ac, add, id, pin, lifetime, confirm)) {
 199                 fprintf(stderr, "Card %s: %s\n",
 200                     add ? "added" : "removed", id);
 201                 ret = 0;
 202         } else {
 203                 fprintf(stderr, "Could not %s card: %s\n",
 204                     add ? "add" : "remove", id);
 205                 ret = -1;
 206         }
 207         xfree(pin);
 208         return ret;
 209 }
 210
 211 static int
 212 list_identities(AuthenticationConnection *ac, int do_fp)
 213 {
 214         Key *key;
 215         char *comment, *fp;
 216         int had_identities = 0;
 217         int version;
 218
 219         for (version = 1; version <= 2; version++) {
 220                 for (key = ssh_get_first_identity(ac, &comment, version);
 221                     key != NULL;
 222                     key = ssh_get_next_identity(ac, &comment, version)) {
 223                         had_identities = 1;
 224                         if (do_fp) {
 225                                 fp = key_fingerprint(key, SSH_FP_MD5,
 226                                     SSH_FP_HEX);
 227                                 printf("%d %s %s (%s)\n",
 228                                     key_size(key), fp, comment, key_type(key));
 229                                 xfree(fp);
 230                         } else {
 231                                 if (!key_write(key, stdout))
 232                                         fprintf(stderr, "key_write failed");
 233                                 fprintf(stdout, " %s\n", comment);
 234                         }
 235                         key_free(key);
 236                         xfree(comment);
 237                 }
 238         }
 239         if (!had_identities) {
 240                 printf("The agent has no identities.\n");
 241                 return -1;
 242         }
 243         return 0;
 244 }
 245
 246 static int
 247 lock_agent(AuthenticationConnection *ac, int lock)
 248 {
 249         char prompt[100], *p1, *p2;
 250         int passok = 1, ret = -1;
 251
 252         strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
 253         p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
 254         if (lock) {
 255                 strlcpy(prompt, "Again: ", sizeof prompt);
 256                 p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
 257                 if (strcmp(p1, p2) != 0) {
 258                         fprintf(stderr, "Passwords do not match.\n");
 259                         passok = 0;
 260                 }
 261                 memset(p2, 0, strlen(p2));
 262                 xfree(p2);
 263         }
 264         if (passok && ssh_lock_agent(ac, lock, p1)) {
 265                 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
 266                 ret = 0;
 267         } else
 268                 fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un");
 269         memset(p1, 0, strlen(p1));
 270         xfree(p1);
 271         return (ret);
 272 }
 273
 274 static int
 275 do_file(AuthenticationConnection *ac, int deleting, char *file)
 276 {
 277         if (deleting) {
 278                 if (delete_file(ac, file) == -1)
 279                         return -1;
 280         } else {
 281                 if (add_file(ac, file) == -1)
 282                         return -1;
 283         }
 284         return 0;
 285 }
 286
 287 static void
 288 usage(void)
 289 {
 290         fprintf(stderr, "Usage: %s [options]\n", __progname);
 291         fprintf(stderr, "Options:\n");
 292         fprintf(stderr, "  -l          List fingerprints of all identities.\n");
 293         fprintf(stderr, "  -L          List public key parameters of all identities.\n");
 294         fprintf(stderr, "  -d          Delete identity.\n");
 295         fprintf(stderr, "  -D          Delete all identities.\n");
 296         fprintf(stderr, "  -x          Lock agent.\n");
 297         fprintf(stderr, "  -X          Unlock agent.\n");
 298         fprintf(stderr, "  -t life     Set lifetime (in seconds) when adding identities.\n");
 299         fprintf(stderr, "  -c          Require confirmation to sign using identities\n");
 300 #ifdef SMARTCARD
 301         fprintf(stderr, "  -s reader   Add key in smartcard reader.\n");
 302         fprintf(stderr, "  -e reader   Remove key in smartcard reader.\n");
 303 #endif
 304 }
 305
 306 int
 307 main(int argc, char **argv)
 308 {
 309         extern char *optarg;
 310         extern int optind;
 311         AuthenticationConnection *ac = NULL;
 312         char *sc_reader_id = NULL;
 313         int i, ch, deleting = 0, ret = 0;
 314
 315         __progname = ssh_get_progname(argv[0]);
 316         init_rng();
 317         seed_rng();
 318
 319         SSLeay_add_all_algorithms();
 320
 321         /* At first, get a connection to the authentication agent. */
 322         ac = ssh_get_authentication_connection();
 323         if (ac == NULL) {
 324                 fprintf(stderr, "Could not open a connection to your authentication agent.\n");
 325                 exit(2);
 326         }
 327         while ((ch = getopt(argc, argv, "lLcdDxXe:s:t:")) != -1) {
 328                 switch (ch) {
 329                 case 'l':
 330                 case 'L':
 331                         if (list_identities(ac, ch == 'l' ? 1 : 0) == -1)
 332                                 ret = 1;
 333                         goto done;
 334                         break;
 335                 case 'x':
 336                 case 'X':
 337                         if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1)
 338                                 ret = 1;
 339                         goto done;
 340                         break;
 341                 case 'c':
 342                         confirm = 1;
 343                         break;
 344                 case 'd':
 345                         deleting = 1;
 346                         break;
 347                 case 'D':
 348                         if (delete_all(ac) == -1)
 349                                 ret = 1;
 350                         goto done;
 351                         break;
 352                 case 's':
 353                         sc_reader_id = optarg;
 354                         break;
 355                 case 'e':
 356                         deleting = 1;
 357                         sc_reader_id = optarg;
 358                         break;
 359                 case 't':
 360                         if ((lifetime = convtime(optarg)) == -1) {
 361                                 fprintf(stderr, "Invalid lifetime\n");
 362                                 ret = 1;
 363                                 goto done;
 364                         }
 365                         break;
 366                 default:
 367                         usage();
 368                         ret = 1;
 369                         goto done;
 370                 }
 371         }
 372         argc -= optind;
 373         argv += optind;
 374         if (sc_reader_id != NULL) {
 375                 if (update_card(ac, !deleting, sc_reader_id) == -1)
 376                         ret = 1;
 377                 goto done;
 378         }
 379         if (argc == 0) {
 380                 char buf[MAXPATHLEN];
 381                 struct passwd *pw;
 382                 struct stat st;
 383                 int count = 0;
 384
 385                 if ((pw = getpwuid(getuid())) == NULL) {
 386                         fprintf(stderr, "No user found with uid %u\n",
 387                             (u_int)getuid());
 388                         ret = 1;
 389                         goto done;
 390                 }
 391
 392                 for (i = 0; default_files[i]; i++) {
 393                         snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
 394                             default_files[i]);
 395                         if (stat(buf, &st) < 0)
 396                                 continue;
 397                         if (do_file(ac, deleting, buf) == -1)
 398                                 ret = 1;
 399                         else
 400                                 count++;
 401                 }
 402                 if (count == 0)
 403                         ret = 1;
 404         } else {
 405                 for (i = 0; i < argc; i++) {
 406                         if (do_file(ac, deleting, argv[i]) == -1)
 407                                 ret = 1;
 408                 }
 409         }
 410         clear_pass();
 411
 412 done:
 413         ssh_close_authentication_connection(ac);
 414         return ret;
 415 }