ssh-add.c

   1 /* $OpenBSD: ssh-add.c,v 1.84 2006/07/17 01:31:09 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 <unistd.h>
  48
  49 #include "ssh.h"
  50 #include "rsa.h"
  51 #include "log.h"
  52 #include "xmalloc.h"
  53 #include "key.h"
  54 #include "authfd.h"
  55 #include "authfile.h"
  56 #include "pathnames.h"
  57 #include "misc.h"
  58
  59 /* argv0 */
  60 extern char *__progname;
  61
  62 /* Default files to add */
  63 static char *default_files[] = {
  64         _PATH_SSH_CLIENT_ID_RSA,
  65         _PATH_SSH_CLIENT_ID_DSA,
  66         _PATH_SSH_CLIENT_IDENTITY,
  67         NULL
  68 };
  69
  70 /* Default lifetime (0 == forever) */
  71 static int lifetime = 0;
  72
  73 /* User has to confirm key use */
  74 static int confirm = 0;
  75
  76 /* we keep a cache of one passphrases */
  77 static char *pass = NULL;
  78 static void
  79 clear_pass(void)
  80 {
  81         if (pass) {
  82                 memset(pass, 0, strlen(pass));
  83                 xfree(pass);
  84                 pass = NULL;
  85         }
  86 }
  87
  88 static int
  89 delete_file(AuthenticationConnection *ac, const char *filename)
  90 {
  91         Key *public;
  92         char *comment = NULL;
  93         int ret = -1;
  94
  95         public = key_load_public(filename, &comment);
  96         if (public == NULL) {
  97                 printf("Bad key file %s\n", filename);
  98                 return -1;
  99         }
 100         if (ssh_remove_identity(ac, public)) {
 101                 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment);
 102                 ret = 0;
 103         } else
 104                 fprintf(stderr, "Could not remove identity: %s\n", filename);
 105
 106         key_free(public);
 107         xfree(comment);
 108
 109         return ret;
 110 }
 111
 112 /* Send a request to remove all identities. */
 113 static int
 114 delete_all(AuthenticationConnection *ac)
 115 {
 116         int ret = -1;
 117
 118         if (ssh_remove_all_identities(ac, 1))
 119                 ret = 0;
 120         /* ignore error-code for ssh2 */
 121         ssh_remove_all_identities(ac, 2);
 122
 123         if (ret == 0)
 124                 fprintf(stderr, "All identities removed.\n");
 125         else
 126                 fprintf(stderr, "Failed to remove all identities.\n");
 127
 128         return ret;
 129 }
 130
 131 static int
 132 add_file(AuthenticationConnection *ac, const char *filename)
 133 {
 134         Key *private;
 135         char *comment = NULL;
 136         char msg[1024];
 137         int fd, perms_ok, ret = -1;
 138
 139         if ((fd = open(filename, O_RDONLY)) < 0) {
 140                 perror(filename);
 141                 return -1;
 142         }
 143
 144         /*
 145          * Since we'll try to load a keyfile multiple times, permission errors
 146          * will occur multiple times, so check perms first and bail if wrong.
 147          */
 148         perms_ok = key_perm_ok(fd, filename);
 149         close(fd);
 150         if (!perms_ok)
 151                 return -1;
 152
 153         /* At first, try empty passphrase */
 154         private = key_load_private(filename, "", &comment);
 155         if (comment == NULL)
 156                 comment = xstrdup(filename);
 157         /* try last */
 158         if (private == NULL && pass != NULL)
 159                 private = key_load_private(filename, pass, NULL);
 160         if (private == NULL) {
 161                 /* clear passphrase since it did not work */
 162                 clear_pass();
 163                 snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ",
 164                     comment);
 165                 for (;;) {
 166                         pass = read_passphrase(msg, RP_ALLOW_STDIN);
 167                         if (strcmp(pass, "") == 0) {
 168                                 clear_pass();
 169                                 xfree(comment);
 170                                 return -1;
 171                         }
 172                         private = key_load_private(filename, pass, &comment);
 173                         if (private != NULL)
 174                                 break;
 175                         clear_pass();
 176                         snprintf(msg, sizeof msg,
 177                             "Bad passphrase, try again for %.200s: ", comment);
 178                 }
 179         }
 180
 181         if (ssh_add_identity_constrained(ac, private, comment, lifetime,
 182             confirm)) {
 183                 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
 184                 ret = 0;
 185                 if (lifetime != 0)
 186                         fprintf(stderr,
 187                             "Lifetime set to %d seconds\n", lifetime);
 188                 if (confirm != 0)
 189                         fprintf(stderr,
 190                             "The user has to confirm each use of the key\n");
 191         } else if (ssh_add_identity(ac, private, comment)) {
 192                 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
 193                 ret = 0;
 194         } else {
 195                 fprintf(stderr, "Could not add identity: %s\n", filename);
 196         }
 197
 198         xfree(comment);
 199         key_free(private);
 200
 201         return ret;
 202 }
 203
 204 static int
 205 update_card(AuthenticationConnection *ac, int add, const char *id)
 206 {
 207         char *pin;
 208         int ret = -1;
 209
 210         pin = read_passphrase("Enter passphrase for smartcard: ", RP_ALLOW_STDIN);
 211         if (pin == NULL)
 212                 return -1;
 213
 214         if (ssh_update_card(ac, add, id, pin, lifetime, confirm)) {
 215                 fprintf(stderr, "Card %s: %s\n",
 216                     add ? "added" : "removed", id);
 217                 ret = 0;
 218         } else {
 219                 fprintf(stderr, "Could not %s card: %s\n",
 220                     add ? "add" : "remove", id);
 221                 ret = -1;
 222         }
 223         xfree(pin);
 224         return ret;
 225 }
 226
 227 static int
 228 list_identities(AuthenticationConnection *ac, int do_fp)
 229 {
 230         Key *key;
 231         char *comment, *fp;
 232         int had_identities = 0;
 233         int version;
 234
 235         for (version = 1; version <= 2; version++) {
 236                 for (key = ssh_get_first_identity(ac, &comment, version);
 237                     key != NULL;
 238                     key = ssh_get_next_identity(ac, &comment, version)) {
 239                         had_identities = 1;
 240                         if (do_fp) {
 241                                 fp = key_fingerprint(key, SSH_FP_MD5,
 242                                     SSH_FP_HEX);
 243                                 printf("%d %s %s (%s)\n",
 244                                     key_size(key), fp, comment, key_type(key));
 245                                 xfree(fp);
 246                         } else {
 247                                 if (!key_write(key, stdout))
 248                                         fprintf(stderr, "key_write failed");
 249                                 fprintf(stdout, " %s\n", comment);
 250                         }
 251                         key_free(key);
 252                         xfree(comment);
 253                 }
 254         }
 255         if (!had_identities) {
 256                 printf("The agent has no identities.\n");
 257                 return -1;
 258         }
 259         return 0;
 260 }
 261
 262 static int
 263 lock_agent(AuthenticationConnection *ac, int lock)
 264 {
 265         char prompt[100], *p1, *p2;
 266         int passok = 1, ret = -1;
 267
 268         strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
 269         p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
 270         if (lock) {
 271                 strlcpy(prompt, "Again: ", sizeof prompt);
 272                 p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
 273                 if (strcmp(p1, p2) != 0) {
 274                         fprintf(stderr, "Passwords do not match.\n");
 275                         passok = 0;
 276                 }
 277                 memset(p2, 0, strlen(p2));
 278                 xfree(p2);
 279         }
 280         if (passok && ssh_lock_agent(ac, lock, p1)) {
 281                 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
 282                 ret = 0;
 283         } else
 284                 fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un");
 285         memset(p1, 0, strlen(p1));
 286         xfree(p1);
 287         return (ret);
 288 }
 289
 290 static int
 291 do_file(AuthenticationConnection *ac, int deleting, char *file)
 292 {
 293         if (deleting) {
 294                 if (delete_file(ac, file) == -1)
 295                         return -1;
 296         } else {
 297                 if (add_file(ac, file) == -1)
 298                         return -1;
 299         }
 300         return 0;
 301 }
 302
 303 static void
 304 usage(void)
 305 {
 306         fprintf(stderr, "Usage: %s [options] [file ...]\n", __progname);
 307         fprintf(stderr, "Options:\n");
 308         fprintf(stderr, "  -l          List fingerprints of all identities.\n");
 309         fprintf(stderr, "  -L          List public key parameters of all identities.\n");
 310         fprintf(stderr, "  -d          Delete identity.\n");
 311         fprintf(stderr, "  -D          Delete all identities.\n");
 312         fprintf(stderr, "  -x          Lock agent.\n");
 313         fprintf(stderr, "  -X          Unlock agent.\n");
 314         fprintf(stderr, "  -t life     Set lifetime (in seconds) when adding identities.\n");
 315         fprintf(stderr, "  -c          Require confirmation to sign using identities\n");
 316 #ifdef SMARTCARD
 317         fprintf(stderr, "  -s reader   Add key in smartcard reader.\n");
 318         fprintf(stderr, "  -e reader   Remove key in smartcard reader.\n");
 319 #endif
 320 }
 321
 322 int
 323 main(int argc, char **argv)
 324 {
 325         extern char *optarg;
 326         extern int optind;
 327         AuthenticationConnection *ac = NULL;
 328         char *sc_reader_id = NULL;
 329         int i, ch, deleting = 0, ret = 0;
 330
 331         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 332         sanitise_stdfd();
 333
 334         __progname = ssh_get_progname(argv[0]);
 335         init_rng();
 336         seed_rng();
 337
 338         SSLeay_add_all_algorithms();
 339
 340         /* At first, get a connection to the authentication agent. */
 341         ac = ssh_get_authentication_connection();
 342         if (ac == NULL) {
 343                 fprintf(stderr,
 344                     "Could not open a connection to your authentication agent.\n");
 345                 exit(2);
 346         }
 347         while ((ch = getopt(argc, argv, "lLcdDxXe:s:t:")) != -1) {
 348                 switch (ch) {
 349                 case 'l':
 350                 case 'L':
 351                         if (list_identities(ac, ch == 'l' ? 1 : 0) == -1)
 352                                 ret = 1;
 353                         goto done;
 354                 case 'x':
 355                 case 'X':
 356                         if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1)
 357                                 ret = 1;
 358                         goto done;
 359                 case 'c':
 360                         confirm = 1;
 361                         break;
 362                 case 'd':
 363                         deleting = 1;
 364                         break;
 365                 case 'D':
 366                         if (delete_all(ac) == -1)
 367                                 ret = 1;
 368                         goto done;
 369                 case 's':
 370                         sc_reader_id = optarg;
 371                         break;
 372                 case 'e':
 373                         deleting = 1;
 374                         sc_reader_id = optarg;
 375                         break;
 376                 case 't':
 377                         if ((lifetime = convtime(optarg)) == -1) {
 378                                 fprintf(stderr, "Invalid lifetime\n");
 379                                 ret = 1;
 380                                 goto done;
 381                         }
 382                         break;
 383                 default:
 384                         usage();
 385                         ret = 1;
 386                         goto done;
 387                 }
 388         }
 389         argc -= optind;
 390         argv += optind;
 391         if (sc_reader_id != NULL) {
 392                 if (update_card(ac, !deleting, sc_reader_id) == -1)
 393                         ret = 1;
 394                 goto done;
 395         }
 396         if (argc == 0) {
 397                 char buf[MAXPATHLEN];
 398                 struct passwd *pw;
 399                 struct stat st;
 400                 int count = 0;
 401
 402                 if ((pw = getpwuid(getuid())) == NULL) {
 403                         fprintf(stderr, "No user found with uid %u\n",
 404                             (u_int)getuid());
 405                         ret = 1;
 406                         goto done;
 407                 }
 408
 409                 for (i = 0; default_files[i]; i++) {
 410                         snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
 411                             default_files[i]);
 412                         if (stat(buf, &st) < 0)
 413                                 continue;
 414                         if (do_file(ac, deleting, buf) == -1)
 415                                 ret = 1;
 416                         else
 417                                 count++;
 418                 }
 419                 if (count == 0)
 420                         ret = 1;
 421         } else {
 422                 for (i = 0; i < argc; i++) {
 423                         if (do_file(ac, deleting, argv[i]) == -1)
 424                                 ret = 1;
 425                 }
 426         }
 427         clear_pass();
 428
 429 done:
 430         ssh_close_authentication_connection(ac);
 431         return ret;
 432 }