ssh-add.c

   1 /* $OpenBSD: ssh-add.c,v 1.80 2006/05/30 11:46:38 mk 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
  43 #include <openssl/evp.h>
  44
  45 #include "ssh.h"
  46 #include "rsa.h"
  47 #include "log.h"
  48 #include "xmalloc.h"
  49 #include "key.h"
  50 #include "authfd.h"
  51 #include "authfile.h"
  52 #include "pathnames.h"
  53 #include "misc.h"
  54
  55 /* argv0 */
  56 extern char *__progname;
  57
  58 /* Default files to add */
  59 static char *default_files[] = {
  60         _PATH_SSH_CLIENT_ID_RSA,
  61         _PATH_SSH_CLIENT_ID_DSA,
  62         _PATH_SSH_CLIENT_IDENTITY,
  63         NULL
  64 };
  65
  66 /* Default lifetime (0 == forever) */
  67 static int lifetime = 0;
  68
  69 /* User has to confirm key use */
  70 static int confirm = 0;
  71
  72 /* we keep a cache of one passphrases */
  73 static char *pass = NULL;
  74 static void
  75 clear_pass(void)
  76 {
  77         if (pass) {
  78                 memset(pass, 0, strlen(pass));
  79                 xfree(pass);
  80                 pass = NULL;
  81         }
  82 }
  83
  84 static int
  85 delete_file(AuthenticationConnection *ac, const char *filename)
  86 {
  87         Key *public;
  88         char *comment = NULL;
  89         int ret = -1;
  90
  91         public = key_load_public(filename, &comment);
  92         if (public == NULL) {
  93                 printf("Bad key file %s\n", filename);
  94                 return -1;
  95         }
  96         if (ssh_remove_identity(ac, public)) {
  97                 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment);
  98                 ret = 0;
  99         } else
 100                 fprintf(stderr, "Could not remove identity: %s\n", filename);
 101
 102         key_free(public);
 103         xfree(comment);
 104
 105         return ret;
 106 }
 107
 108 /* Send a request to remove all identities. */
 109 static int
 110 delete_all(AuthenticationConnection *ac)
 111 {
 112         int ret = -1;
 113
 114         if (ssh_remove_all_identities(ac, 1))
 115                 ret = 0;
 116         /* ignore error-code for ssh2 */
 117         ssh_remove_all_identities(ac, 2);
 118
 119         if (ret == 0)
 120                 fprintf(stderr, "All identities removed.\n");
 121         else
 122                 fprintf(stderr, "Failed to remove all identities.\n");
 123
 124         return ret;
 125 }
 126
 127 static int
 128 add_file(AuthenticationConnection *ac, const char *filename)
 129 {
 130         Key *private;
 131         char *comment = NULL;
 132         char msg[1024];
 133         int fd, perms_ok, ret = -1;
 134
 135         if ((fd = open(filename, 0)) < 0) {
 136                 perror(filename);
 137                 return -1;
 138         }
 139
 140         /*
 141          * Since we'll try to load a keyfile multiple times, permission errors
 142          * will occur multiple times, so check perms first and bail if wrong.
 143          */
 144         perms_ok = key_perm_ok(fd, filename);
 145         close(fd);
 146         if (!perms_ok)
 147                 return -1;
 148
 149         /* At first, try empty passphrase */
 150         private = key_load_private(filename, "", &comment);
 151         if (comment == NULL)
 152                 comment = xstrdup(filename);
 153         /* try last */
 154         if (private == NULL && pass != NULL)
 155                 private = key_load_private(filename, pass, NULL);
 156         if (private == NULL) {
 157                 /* clear passphrase since it did not work */
 158                 clear_pass();
 159                 snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ",
 160                     comment);
 161                 for (;;) {
 162                         pass = read_passphrase(msg, RP_ALLOW_STDIN);
 163                         if (strcmp(pass, "") == 0) {
 164                                 clear_pass();
 165                                 xfree(comment);
 166                                 return -1;
 167                         }
 168                         private = key_load_private(filename, pass, &comment);
 169                         if (private != NULL)
 170                                 break;
 171                         clear_pass();
 172                         snprintf(msg, sizeof msg,
 173                             "Bad passphrase, try again for %.200s: ", comment);
 174                 }
 175         }
 176
 177         if (ssh_add_identity_constrained(ac, private, comment, lifetime,
 178             confirm)) {
 179                 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
 180                 ret = 0;
 181                 if (lifetime != 0)
 182                         fprintf(stderr,
 183                             "Lifetime set to %d seconds\n", lifetime);
 184                 if (confirm != 0)
 185                         fprintf(stderr,
 186                             "The user has to confirm each use of the key\n");
 187         } else if (ssh_add_identity(ac, private, comment)) {
 188                 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
 189                 ret = 0;
 190         } else {
 191                 fprintf(stderr, "Could not add identity: %s\n", filename);
 192         }
 193
 194         xfree(comment);
 195         key_free(private);
 196
 197         return ret;
 198 }
 199
 200 static int
 201 update_card(AuthenticationConnection *ac, int add, const char *id)
 202 {
 203         char *pin;
 204         int ret = -1;
 205
 206         pin = read_passphrase("Enter passphrase for smartcard: ", RP_ALLOW_STDIN);
 207         if (pin == NULL)
 208                 return -1;
 209
 210         if (ssh_update_card(ac, add, id, pin, lifetime, confirm)) {
 211                 fprintf(stderr, "Card %s: %s\n",
 212                     add ? "added" : "removed", id);
 213                 ret = 0;
 214         } else {
 215                 fprintf(stderr, "Could not %s card: %s\n",
 216                     add ? "add" : "remove", id);
 217                 ret = -1;
 218         }
 219         xfree(pin);
 220         return ret;
 221 }
 222
 223 static int
 224 list_identities(AuthenticationConnection *ac, int do_fp)
 225 {
 226         Key *key;
 227         char *comment, *fp;
 228         int had_identities = 0;
 229         int version;
 230
 231         for (version = 1; version <= 2; version++) {
 232                 for (key = ssh_get_first_identity(ac, &comment, version);
 233                     key != NULL;
 234                     key = ssh_get_next_identity(ac, &comment, version)) {
 235                         had_identities = 1;
 236                         if (do_fp) {
 237                                 fp = key_fingerprint(key, SSH_FP_MD5,
 238                                     SSH_FP_HEX);
 239                                 printf("%d %s %s (%s)\n",
 240                                     key_size(key), fp, comment, key_type(key));
 241                                 xfree(fp);
 242                         } else {
 243                                 if (!key_write(key, stdout))
 244                                         fprintf(stderr, "key_write failed");
 245                                 fprintf(stdout, " %s\n", comment);
 246                         }
 247                         key_free(key);
 248                         xfree(comment);
 249                 }
 250         }
 251         if (!had_identities) {
 252                 printf("The agent has no identities.\n");
 253                 return -1;
 254         }
 255         return 0;
 256 }
 257
 258 static int
 259 lock_agent(AuthenticationConnection *ac, int lock)
 260 {
 261         char prompt[100], *p1, *p2;
 262         int passok = 1, ret = -1;
 263
 264         strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
 265         p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
 266         if (lock) {
 267                 strlcpy(prompt, "Again: ", sizeof prompt);
 268                 p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
 269                 if (strcmp(p1, p2) != 0) {
 270                         fprintf(stderr, "Passwords do not match.\n");
 271                         passok = 0;
 272                 }
 273                 memset(p2, 0, strlen(p2));
 274                 xfree(p2);
 275         }
 276         if (passok && ssh_lock_agent(ac, lock, p1)) {
 277                 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
 278                 ret = 0;
 279         } else
 280                 fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un");
 281         memset(p1, 0, strlen(p1));
 282         xfree(p1);
 283         return (ret);
 284 }
 285
 286 static int
 287 do_file(AuthenticationConnection *ac, int deleting, char *file)
 288 {
 289         if (deleting) {
 290                 if (delete_file(ac, file) == -1)
 291                         return -1;
 292         } else {
 293                 if (add_file(ac, file) == -1)
 294                         return -1;
 295         }
 296         return 0;
 297 }
 298
 299 static void
 300 usage(void)
 301 {
 302         fprintf(stderr, "Usage: %s [options] [file ...]\n", __progname);
 303         fprintf(stderr, "Options:\n");
 304         fprintf(stderr, "  -l          List fingerprints of all identities.\n");
 305         fprintf(stderr, "  -L          List public key parameters of all identities.\n");
 306         fprintf(stderr, "  -d          Delete identity.\n");
 307         fprintf(stderr, "  -D          Delete all identities.\n");
 308         fprintf(stderr, "  -x          Lock agent.\n");
 309         fprintf(stderr, "  -X          Unlock agent.\n");
 310         fprintf(stderr, "  -t life     Set lifetime (in seconds) when adding identities.\n");
 311         fprintf(stderr, "  -c          Require confirmation to sign using identities\n");
 312 #ifdef SMARTCARD
 313         fprintf(stderr, "  -s reader   Add key in smartcard reader.\n");
 314         fprintf(stderr, "  -e reader   Remove key in smartcard reader.\n");
 315 #endif
 316 }
 317
 318 int
 319 main(int argc, char **argv)
 320 {
 321         extern char *optarg;
 322         extern int optind;
 323         AuthenticationConnection *ac = NULL;
 324         char *sc_reader_id = NULL;
 325         int i, ch, deleting = 0, ret = 0;
 326
 327         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 328         sanitise_stdfd();
 329
 330         __progname = ssh_get_progname(argv[0]);
 331         init_rng();
 332         seed_rng();
 333
 334         SSLeay_add_all_algorithms();
 335
 336         /* At first, get a connection to the authentication agent. */
 337         ac = ssh_get_authentication_connection();
 338         if (ac == NULL) {
 339                 fprintf(stderr,
 340                     "Could not open a connection to your authentication agent.\n");
 341                 exit(2);
 342         }
 343         while ((ch = getopt(argc, argv, "lLcdDxXe:s:t:")) != -1) {
 344                 switch (ch) {
 345                 case 'l':
 346                 case 'L':
 347                         if (list_identities(ac, ch == 'l' ? 1 : 0) == -1)
 348                                 ret = 1;
 349                         goto done;
 350                 case 'x':
 351                 case 'X':
 352                         if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1)
 353                                 ret = 1;
 354                         goto done;
 355                 case 'c':
 356                         confirm = 1;
 357                         break;
 358                 case 'd':
 359                         deleting = 1;
 360                         break;
 361                 case 'D':
 362                         if (delete_all(ac) == -1)
 363                                 ret = 1;
 364                         goto done;
 365                 case 's':
 366                         sc_reader_id = optarg;
 367                         break;
 368                 case 'e':
 369                         deleting = 1;
 370                         sc_reader_id = optarg;
 371                         break;
 372                 case 't':
 373                         if ((lifetime = convtime(optarg)) == -1) {
 374                                 fprintf(stderr, "Invalid lifetime\n");
 375                                 ret = 1;
 376                                 goto done;
 377                         }
 378                         break;
 379                 default:
 380                         usage();
 381                         ret = 1;
 382                         goto done;
 383                 }
 384         }
 385         argc -= optind;
 386         argv += optind;
 387         if (sc_reader_id != NULL) {
 388                 if (update_card(ac, !deleting, sc_reader_id) == -1)
 389                         ret = 1;
 390                 goto done;
 391         }
 392         if (argc == 0) {
 393                 char buf[MAXPATHLEN];
 394                 struct passwd *pw;
 395                 struct stat st;
 396                 int count = 0;
 397
 398                 if ((pw = getpwuid(getuid())) == NULL) {
 399                         fprintf(stderr, "No user found with uid %u\n",
 400                             (u_int)getuid());
 401                         ret = 1;
 402                         goto done;
 403                 }
 404
 405                 for (i = 0; default_files[i]; i++) {
 406                         snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
 407                             default_files[i]);
 408                         if (stat(buf, &st) < 0)
 409                                 continue;
 410                         if (do_file(ac, deleting, buf) == -1)
 411                                 ret = 1;
 412                         else
 413                                 count++;
 414                 }
 415                 if (count == 0)
 416                         ret = 1;
 417         } else {
 418                 for (i = 0; i < argc; i++) {
 419                         if (do_file(ac, deleting, argv[i]) == -1)
 420                                 ret = 1;
 421                 }
 422         }
 423         clear_pass();
 424
 425 done:
 426         ssh_close_authentication_connection(ac);
 427         return ret;
 428 }