crypto/openssh-4/ssh-add.c

   1 /* $OpenBSD: ssh-add.c,v 1.89 2006/08/03 03:34:42 deraadt 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
  46 #include <fcntl.h>
  47 #include <pwd.h>
  48 #include <stdarg.h>
  49 #include <stdio.h>
  50 #include <stdlib.h>
  51 #include <string.h>
  52 #include <unistd.h>
  53
  54 #include "xmalloc.h"
  55 #include "ssh.h"
  56 #include "rsa.h"
  57 #include "log.h"
  58 #include "key.h"
  59 #include "buffer.h"
  60 #include "authfd.h"
  61 #include "authfile.h"
  62 #include "pathnames.h"
  63 #include "misc.h"
  64
  65 /* argv0 */
  66 extern char *__progname;
  67
  68 /* Default files to add */
  69 static char *default_files[] = {
  70         _PATH_SSH_CLIENT_ID_RSA,
  71         _PATH_SSH_CLIENT_ID_DSA,
  72         _PATH_SSH_CLIENT_IDENTITY,
  73         NULL
  74 };
  75
  76 /* Default lifetime (0 == forever) */
  77 static int lifetime = 0;
  78
  79 /* User has to confirm key use */
  80 static int confirm = 0;
  81
  82 /* we keep a cache of one passphrases */
  83 static char *pass = NULL;
  84 static void
  85 clear_pass(void)
  86 {
  87         if (pass) {
  88                 memset(pass, 0, strlen(pass));
  89                 xfree(pass);
  90                 pass = NULL;
  91         }
  92 }
  93
  94 static int
  95 delete_file(AuthenticationConnection *ac, const char *filename)
  96 {
  97         Key *public;
  98         char *comment = NULL;
  99         int ret = -1;
 100
 101         public = key_load_public(filename, &comment);
 102         if (public == NULL) {
 103                 printf("Bad key file %s\n", filename);
 104                 return -1;
 105         }
 106         if (ssh_remove_identity(ac, public)) {
 107                 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment);
 108                 ret = 0;
 109         } else
 110                 fprintf(stderr, "Could not remove identity: %s\n", filename);
 111
 112         key_free(public);
 113         xfree(comment);
 114
 115         return ret;
 116 }
 117
 118 /* Send a request to remove all identities. */
 119 static int
 120 delete_all(AuthenticationConnection *ac)
 121 {
 122         int ret = -1;
 123
 124         if (ssh_remove_all_identities(ac, 1))
 125                 ret = 0;
 126         /* ignore error-code for ssh2 */
 127         ssh_remove_all_identities(ac, 2);
 128
 129         if (ret == 0)
 130                 fprintf(stderr, "All identities removed.\n");
 131         else
 132                 fprintf(stderr, "Failed to remove all identities.\n");
 133
 134         return ret;
 135 }
 136
 137 static int
 138 add_file(AuthenticationConnection *ac, const char *filename)
 139 {
 140         Key *private;
 141         char *comment = NULL;
 142         char msg[1024];
 143         int fd, perms_ok, ret = -1;
 144
 145         if ((fd = open(filename, O_RDONLY)) < 0) {
 146                 perror(filename);
 147                 return -1;
 148         }
 149
 150         /*
 151          * Since we'll try to load a keyfile multiple times, permission errors
 152          * will occur multiple times, so check perms first and bail if wrong.
 153          */
 154         perms_ok = key_perm_ok(fd, filename);
 155         close(fd);
 156         if (!perms_ok)
 157                 return -1;
 158
 159         /* At first, try empty passphrase */
 160         private = key_load_private(filename, "", &comment);
 161         if (comment == NULL)
 162                 comment = xstrdup(filename);
 163         /* try last */
 164         if (private == NULL && pass != NULL)
 165                 private = key_load_private(filename, pass, NULL);
 166         if (private == NULL) {
 167                 /* clear passphrase since it did not work */
 168                 clear_pass();
 169                 snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ",
 170                     comment);
 171                 for (;;) {
 172                         pass = read_passphrase(msg, RP_ALLOW_STDIN);
 173                         if (strcmp(pass, "") == 0) {
 174                                 clear_pass();
 175                                 xfree(comment);
 176                                 return -1;
 177                         }
 178                         private = key_load_private(filename, pass, &comment);
 179                         if (private != NULL)
 180                                 break;
 181                         clear_pass();
 182                         snprintf(msg, sizeof msg,
 183                             "Bad passphrase, try again for %.200s: ", comment);
 184                 }
 185         }
 186
 187         if (ssh_add_identity_constrained(ac, private, comment, lifetime,
 188             confirm)) {
 189                 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
 190                 ret = 0;
 191                 if (lifetime != 0)
 192                         fprintf(stderr,
 193                             "Lifetime set to %d seconds\n", lifetime);
 194                 if (confirm != 0)
 195                         fprintf(stderr,
 196                             "The user has to confirm each use of the key\n");
 197         } else if (ssh_add_identity(ac, private, comment)) {
 198                 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
 199                 ret = 0;
 200         } else {
 201                 fprintf(stderr, "Could not add identity: %s\n", filename);
 202         }
 203
 204         xfree(comment);
 205         key_free(private);
 206
 207         return ret;
 208 }
 209
 210 static int
 211 update_card(AuthenticationConnection *ac, int add, const char *id)
 212 {
 213         char *pin;
 214         int ret = -1;
 215
 216         pin = read_passphrase("Enter passphrase for smartcard: ", RP_ALLOW_STDIN);
 217         if (pin == NULL)
 218                 return -1;
 219
 220         if (ssh_update_card(ac, add, id, pin, lifetime, confirm)) {
 221                 fprintf(stderr, "Card %s: %s\n",
 222                     add ? "added" : "removed", id);
 223                 ret = 0;
 224         } else {
 225                 fprintf(stderr, "Could not %s card: %s\n",
 226                     add ? "add" : "remove", id);
 227                 ret = -1;
 228         }
 229         xfree(pin);
 230         return ret;
 231 }
 232
 233 static int
 234 list_identities(AuthenticationConnection *ac, int do_fp)
 235 {
 236         Key *key;
 237         char *comment, *fp;
 238         int had_identities = 0;
 239         int version;
 240
 241         for (version = 1; version <= 2; version++) {
 242                 for (key = ssh_get_first_identity(ac, &comment, version);
 243                     key != NULL;
 244                     key = ssh_get_next_identity(ac, &comment, version)) {
 245                         had_identities = 1;
 246                         if (do_fp) {
 247                                 fp = key_fingerprint(key, SSH_FP_MD5,
 248                                     SSH_FP_HEX);
 249                                 printf("%d %s %s (%s)\n",
 250                                     key_size(key), fp, comment, key_type(key));
 251                                 xfree(fp);
 252                         } else {
 253                                 if (!key_write(key, stdout))
 254                                         fprintf(stderr, "key_write failed");
 255                                 fprintf(stdout, " %s\n", comment);
 256                         }
 257                         key_free(key);
 258                         xfree(comment);
 259                 }
 260         }
 261         if (!had_identities) {
 262                 printf("The agent has no identities.\n");
 263                 return -1;
 264         }
 265         return 0;
 266 }
 267
 268 static int
 269 lock_agent(AuthenticationConnection *ac, int lock)
 270 {
 271         char prompt[100], *p1, *p2;
 272         int passok = 1, ret = -1;
 273
 274         strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
 275         p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
 276         if (lock) {
 277                 strlcpy(prompt, "Again: ", sizeof prompt);
 278                 p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
 279                 if (strcmp(p1, p2) != 0) {
 280                         fprintf(stderr, "Passwords do not match.\n");
 281                         passok = 0;
 282                 }
 283                 memset(p2, 0, strlen(p2));
 284                 xfree(p2);
 285         }
 286         if (passok && ssh_lock_agent(ac, lock, p1)) {
 287                 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
 288                 ret = 0;
 289         } else
 290                 fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un");
 291         memset(p1, 0, strlen(p1));
 292         xfree(p1);
 293         return (ret);
 294 }
 295
 296 static int
 297 do_file(AuthenticationConnection *ac, int deleting, char *file)
 298 {
 299         if (deleting) {
 300                 if (delete_file(ac, file) == -1)
 301                         return -1;
 302         } else {
 303                 if (add_file(ac, file) == -1)
 304                         return -1;
 305         }
 306         return 0;
 307 }
 308
 309 static void
 310 usage(void)
 311 {
 312         fprintf(stderr, "Usage: %s [options] [file ...]\n", __progname);
 313         fprintf(stderr, "Options:\n");
 314         fprintf(stderr, "  -l          List fingerprints of all identities.\n");
 315         fprintf(stderr, "  -L          List public key parameters of all identities.\n");
 316         fprintf(stderr, "  -d          Delete identity.\n");
 317         fprintf(stderr, "  -D          Delete all identities.\n");
 318         fprintf(stderr, "  -x          Lock agent.\n");
 319         fprintf(stderr, "  -X          Unlock agent.\n");
 320         fprintf(stderr, "  -t life     Set lifetime (in seconds) when adding identities.\n");
 321         fprintf(stderr, "  -c          Require confirmation to sign using identities\n");
 322 #ifdef SMARTCARD
 323         fprintf(stderr, "  -s reader   Add key in smartcard reader.\n");
 324         fprintf(stderr, "  -e reader   Remove key in smartcard reader.\n");
 325 #endif
 326 }
 327
 328 int
 329 main(int argc, char **argv)
 330 {
 331         extern char *optarg;
 332         extern int optind;
 333         AuthenticationConnection *ac = NULL;
 334         char *sc_reader_id = NULL;
 335         int i, ch, deleting = 0, ret = 0;
 336
 337         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 338         sanitise_stdfd();
 339
 340         __progname = ssh_get_progname(argv[0]);
 341         init_rng();
 342         seed_rng();
 343
 344         SSLeay_add_all_algorithms();
 345
 346         /* At first, get a connection to the authentication agent. */
 347         ac = ssh_get_authentication_connection();
 348         if (ac == NULL) {
 349                 fprintf(stderr,
 350                     "Could not open a connection to your authentication agent.\n");
 351                 exit(2);
 352         }
 353         while ((ch = getopt(argc, argv, "lLcdDxXe:s:t:")) != -1) {
 354                 switch (ch) {
 355                 case 'l':
 356                 case 'L':
 357                         if (list_identities(ac, ch == 'l' ? 1 : 0) == -1)
 358                                 ret = 1;
 359                         goto done;
 360                 case 'x':
 361                 case 'X':
 362                         if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1)
 363                                 ret = 1;
 364                         goto done;
 365                 case 'c':
 366                         confirm = 1;
 367                         break;
 368                 case 'd':
 369                         deleting = 1;
 370                         break;
 371                 case 'D':
 372                         if (delete_all(ac) == -1)
 373                                 ret = 1;
 374                         goto done;
 375                 case 's':
 376                         sc_reader_id = optarg;
 377                         break;
 378                 case 'e':
 379                         deleting = 1;
 380                         sc_reader_id = optarg;
 381                         break;
 382                 case 't':
 383                         if ((lifetime = convtime(optarg)) == -1) {
 384                                 fprintf(stderr, "Invalid lifetime\n");
 385                                 ret = 1;
 386                                 goto done;
 387                         }
 388                         break;
 389                 default:
 390                         usage();
 391                         ret = 1;
 392                         goto done;
 393                 }
 394         }
 395         argc -= optind;
 396         argv += optind;
 397         if (sc_reader_id != NULL) {
 398                 if (update_card(ac, !deleting, sc_reader_id) == -1)
 399                         ret = 1;
 400                 goto done;
 401         }
 402         if (argc == 0) {
 403                 char buf[MAXPATHLEN];
 404                 struct passwd *pw;
 405                 struct stat st;
 406                 int count = 0;
 407
 408                 if ((pw = getpwuid(getuid())) == NULL) {
 409                         fprintf(stderr, "No user found with uid %u\n",
 410                             (u_int)getuid());
 411                         ret = 1;
 412                         goto done;
 413                 }
 414
 415                 for (i = 0; default_files[i]; i++) {
 416                         snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
 417                             default_files[i]);
 418                         if (stat(buf, &st) < 0)
 419                                 continue;
 420                         if (do_file(ac, deleting, buf) == -1)
 421                                 ret = 1;
 422                         else
 423                                 count++;
 424                 }
 425                 if (count == 0)
 426                         ret = 1;
 427         } else {
 428                 for (i = 0; i < argc; i++) {
 429                         if (do_file(ac, deleting, argv[i]) == -1)
 430                                 ret = 1;
 431                 }
 432         }
 433         clear_pass();
 434
 435 done:
 436         ssh_close_authentication_connection(ac);
 437         return ret;
 438 }