ssh-add.c

   1 /* $OpenBSD: ssh-add.c,v 1.85 2006/07/22 20:48:23 stevesk 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 <fcntl.h>
  46 #include <pwd.h>
  47 #include <string.h>
  48 #include <unistd.h>
  49
  50 #include "ssh.h"
  51 #include "rsa.h"
  52 #include "log.h"
  53 #include "xmalloc.h"
  54 #include "key.h"
  55 #include "authfd.h"
  56 #include "authfile.h"
  57 #include "pathnames.h"
  58 #include "misc.h"
  59
  60 /* argv0 */
  61 extern char *__progname;
  62
  63 /* Default files to add */
  64 static char *default_files[] = {
  65         _PATH_SSH_CLIENT_ID_RSA,
  66         _PATH_SSH_CLIENT_ID_DSA,
  67         _PATH_SSH_CLIENT_IDENTITY,
  68         NULL
  69 };
  70
  71 /* Default lifetime (0 == forever) */
  72 static int lifetime = 0;
  73
  74 /* User has to confirm key use */
  75 static int confirm = 0;
  76
  77 /* we keep a cache of one passphrases */
  78 static char *pass = NULL;
  79 static void
  80 clear_pass(void)
  81 {
  82         if (pass) {
  83                 memset(pass, 0, strlen(pass));
  84                 xfree(pass);
  85                 pass = NULL;
  86         }
  87 }
  88
  89 static int
  90 delete_file(AuthenticationConnection *ac, const char *filename)
  91 {
  92         Key *public;
  93         char *comment = NULL;
  94         int ret = -1;
  95
  96         public = key_load_public(filename, &comment);
  97         if (public == NULL) {
  98                 printf("Bad key file %s\n", filename);
  99                 return -1;
 100         }
 101         if (ssh_remove_identity(ac, public)) {
 102                 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment);
 103                 ret = 0;
 104         } else
 105                 fprintf(stderr, "Could not remove identity: %s\n", filename);
 106
 107         key_free(public);
 108         xfree(comment);
 109
 110         return ret;
 111 }
 112
 113 /* Send a request to remove all identities. */
 114 static int
 115 delete_all(AuthenticationConnection *ac)
 116 {
 117         int ret = -1;
 118
 119         if (ssh_remove_all_identities(ac, 1))
 120                 ret = 0;
 121         /* ignore error-code for ssh2 */
 122         ssh_remove_all_identities(ac, 2);
 123
 124         if (ret == 0)
 125                 fprintf(stderr, "All identities removed.\n");
 126         else
 127                 fprintf(stderr, "Failed to remove all identities.\n");
 128
 129         return ret;
 130 }
 131
 132 static int
 133 add_file(AuthenticationConnection *ac, const char *filename)
 134 {
 135         Key *private;
 136         char *comment = NULL;
 137         char msg[1024];
 138         int fd, perms_ok, ret = -1;
 139
 140         if ((fd = open(filename, O_RDONLY)) < 0) {
 141                 perror(filename);
 142                 return -1;
 143         }
 144
 145         /*
 146          * Since we'll try to load a keyfile multiple times, permission errors
 147          * will occur multiple times, so check perms first and bail if wrong.
 148          */
 149         perms_ok = key_perm_ok(fd, filename);
 150         close(fd);
 151         if (!perms_ok)
 152                 return -1;
 153
 154         /* At first, try empty passphrase */
 155         private = key_load_private(filename, "", &comment);
 156         if (comment == NULL)
 157                 comment = xstrdup(filename);
 158         /* try last */
 159         if (private == NULL && pass != NULL)
 160                 private = key_load_private(filename, pass, NULL);
 161         if (private == NULL) {
 162                 /* clear passphrase since it did not work */
 163                 clear_pass();
 164                 snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ",
 165                     comment);
 166                 for (;;) {
 167                         pass = read_passphrase(msg, RP_ALLOW_STDIN);
 168                         if (strcmp(pass, "") == 0) {
 169                                 clear_pass();
 170                                 xfree(comment);
 171                                 return -1;
 172                         }
 173                         private = key_load_private(filename, pass, &comment);
 174                         if (private != NULL)
 175                                 break;
 176                         clear_pass();
 177                         snprintf(msg, sizeof msg,
 178                             "Bad passphrase, try again for %.200s: ", comment);
 179                 }
 180         }
 181
 182         if (ssh_add_identity_constrained(ac, private, comment, lifetime,
 183             confirm)) {
 184                 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
 185                 ret = 0;
 186                 if (lifetime != 0)
 187                         fprintf(stderr,
 188                             "Lifetime set to %d seconds\n", lifetime);
 189                 if (confirm != 0)
 190                         fprintf(stderr,
 191                             "The user has to confirm each use of the key\n");
 192         } else if (ssh_add_identity(ac, private, comment)) {
 193                 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
 194                 ret = 0;
 195         } else {
 196                 fprintf(stderr, "Could not add identity: %s\n", filename);
 197         }
 198
 199         xfree(comment);
 200         key_free(private);
 201
 202         return ret;
 203 }
 204
 205 static int
 206 update_card(AuthenticationConnection *ac, int add, const char *id)
 207 {
 208         char *pin;
 209         int ret = -1;
 210
 211         pin = read_passphrase("Enter passphrase for smartcard: ", RP_ALLOW_STDIN);
 212         if (pin == NULL)
 213                 return -1;
 214
 215         if (ssh_update_card(ac, add, id, pin, lifetime, confirm)) {
 216                 fprintf(stderr, "Card %s: %s\n",
 217                     add ? "added" : "removed", id);
 218                 ret = 0;
 219         } else {
 220                 fprintf(stderr, "Could not %s card: %s\n",
 221                     add ? "add" : "remove", id);
 222                 ret = -1;
 223         }
 224         xfree(pin);
 225         return ret;
 226 }
 227
 228 static int
 229 list_identities(AuthenticationConnection *ac, int do_fp)
 230 {
 231         Key *key;
 232         char *comment, *fp;
 233         int had_identities = 0;
 234         int version;
 235
 236         for (version = 1; version <= 2; version++) {
 237                 for (key = ssh_get_first_identity(ac, &comment, version);
 238                     key != NULL;
 239                     key = ssh_get_next_identity(ac, &comment, version)) {
 240                         had_identities = 1;
 241                         if (do_fp) {
 242                                 fp = key_fingerprint(key, SSH_FP_MD5,
 243                                     SSH_FP_HEX);
 244                                 printf("%d %s %s (%s)\n",
 245                                     key_size(key), fp, comment, key_type(key));
 246                                 xfree(fp);
 247                         } else {
 248                                 if (!key_write(key, stdout))
 249                                         fprintf(stderr, "key_write failed");
 250                                 fprintf(stdout, " %s\n", comment);
 251                         }
 252                         key_free(key);
 253                         xfree(comment);
 254                 }
 255         }
 256         if (!had_identities) {
 257                 printf("The agent has no identities.\n");
 258                 return -1;
 259         }
 260         return 0;
 261 }
 262
 263 static int
 264 lock_agent(AuthenticationConnection *ac, int lock)
 265 {
 266         char prompt[100], *p1, *p2;
 267         int passok = 1, ret = -1;
 268
 269         strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
 270         p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
 271         if (lock) {
 272                 strlcpy(prompt, "Again: ", sizeof prompt);
 273                 p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
 274                 if (strcmp(p1, p2) != 0) {
 275                         fprintf(stderr, "Passwords do not match.\n");
 276                         passok = 0;
 277                 }
 278                 memset(p2, 0, strlen(p2));
 279                 xfree(p2);
 280         }
 281         if (passok && ssh_lock_agent(ac, lock, p1)) {
 282                 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
 283                 ret = 0;
 284         } else
 285                 fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un");
 286         memset(p1, 0, strlen(p1));
 287         xfree(p1);
 288         return (ret);
 289 }
 290
 291 static int
 292 do_file(AuthenticationConnection *ac, int deleting, char *file)
 293 {
 294         if (deleting) {
 295                 if (delete_file(ac, file) == -1)
 296                         return -1;
 297         } else {
 298                 if (add_file(ac, file) == -1)
 299                         return -1;
 300         }
 301         return 0;
 302 }
 303
 304 static void
 305 usage(void)
 306 {
 307         fprintf(stderr, "Usage: %s [options] [file ...]\n", __progname);
 308         fprintf(stderr, "Options:\n");
 309         fprintf(stderr, "  -l          List fingerprints of all identities.\n");
 310         fprintf(stderr, "  -L          List public key parameters of all identities.\n");
 311         fprintf(stderr, "  -d          Delete identity.\n");
 312         fprintf(stderr, "  -D          Delete all identities.\n");
 313         fprintf(stderr, "  -x          Lock agent.\n");
 314         fprintf(stderr, "  -X          Unlock agent.\n");
 315         fprintf(stderr, "  -t life     Set lifetime (in seconds) when adding identities.\n");
 316         fprintf(stderr, "  -c          Require confirmation to sign using identities\n");
 317 #ifdef SMARTCARD
 318         fprintf(stderr, "  -s reader   Add key in smartcard reader.\n");
 319         fprintf(stderr, "  -e reader   Remove key in smartcard reader.\n");
 320 #endif
 321 }
 322
 323 int
 324 main(int argc, char **argv)
 325 {
 326         extern char *optarg;
 327         extern int optind;
 328         AuthenticationConnection *ac = NULL;
 329         char *sc_reader_id = NULL;
 330         int i, ch, deleting = 0, ret = 0;
 331
 332         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 333         sanitise_stdfd();
 334
 335         __progname = ssh_get_progname(argv[0]);
 336         init_rng();
 337         seed_rng();
 338
 339         SSLeay_add_all_algorithms();
 340
 341         /* At first, get a connection to the authentication agent. */
 342         ac = ssh_get_authentication_connection();
 343         if (ac == NULL) {
 344                 fprintf(stderr,
 345                     "Could not open a connection to your authentication agent.\n");
 346                 exit(2);
 347         }
 348         while ((ch = getopt(argc, argv, "lLcdDxXe:s:t:")) != -1) {
 349                 switch (ch) {
 350                 case 'l':
 351                 case 'L':
 352                         if (list_identities(ac, ch == 'l' ? 1 : 0) == -1)
 353                                 ret = 1;
 354                         goto done;
 355                 case 'x':
 356                 case 'X':
 357                         if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1)
 358                                 ret = 1;
 359                         goto done;
 360                 case 'c':
 361                         confirm = 1;
 362                         break;
 363                 case 'd':
 364                         deleting = 1;
 365                         break;
 366                 case 'D':
 367                         if (delete_all(ac) == -1)
 368                                 ret = 1;
 369                         goto done;
 370                 case 's':
 371                         sc_reader_id = optarg;
 372                         break;
 373                 case 'e':
 374                         deleting = 1;
 375                         sc_reader_id = optarg;
 376                         break;
 377                 case 't':
 378                         if ((lifetime = convtime(optarg)) == -1) {
 379                                 fprintf(stderr, "Invalid lifetime\n");
 380                                 ret = 1;
 381                                 goto done;
 382                         }
 383                         break;
 384                 default:
 385                         usage();
 386                         ret = 1;
 387                         goto done;
 388                 }
 389         }
 390         argc -= optind;
 391         argv += optind;
 392         if (sc_reader_id != NULL) {
 393                 if (update_card(ac, !deleting, sc_reader_id) == -1)
 394                         ret = 1;
 395                 goto done;
 396         }
 397         if (argc == 0) {
 398                 char buf[MAXPATHLEN];
 399                 struct passwd *pw;
 400                 struct stat st;
 401                 int count = 0;
 402
 403                 if ((pw = getpwuid(getuid())) == NULL) {
 404                         fprintf(stderr, "No user found with uid %u\n",
 405                             (u_int)getuid());
 406                         ret = 1;
 407                         goto done;
 408                 }
 409
 410                 for (i = 0; default_files[i]; i++) {
 411                         snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
 412                             default_files[i]);
 413                         if (stat(buf, &st) < 0)
 414                                 continue;
 415                         if (do_file(ac, deleting, buf) == -1)
 416                                 ret = 1;
 417                         else
 418                                 count++;
 419                 }
 420                 if (count == 0)
 421                         ret = 1;
 422         } else {
 423                 for (i = 0; i < argc; i++) {
 424                         if (do_file(ac, deleting, argv[i]) == -1)
 425                                 ret = 1;
 426                 }
 427         }
 428         clear_pass();
 429
 430 done:
 431         ssh_close_authentication_connection(ac);
 432         return ret;
 433 }