ssh-add.c

   1 /* $OpenBSD: ssh-add.c,v 1.96 2010/05/14 00:47:22 djm 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 #include "openbsd-compat/openssl-compat.h"
  46
  47 #include <fcntl.h>
  48 #include <pwd.h>
  49 #include <stdarg.h>
  50 #include <stdio.h>
  51 #include <stdlib.h>
  52 #include <string.h>
  53 #include <unistd.h>
  54
  55 #include "xmalloc.h"
  56 #include "ssh.h"
  57 #include "rsa.h"
  58 #include "log.h"
  59 #include "key.h"
  60 #include "buffer.h"
  61 #include "authfd.h"
  62 #include "authfile.h"
  63 #include "pathnames.h"
  64 #include "misc.h"
  65
  66 /* argv0 */
  67 extern char *__progname;
  68
  69 /* Default files to add */
  70 static char *default_files[] = {
  71         _PATH_SSH_CLIENT_ID_RSA,
  72         _PATH_SSH_CLIENT_ID_DSA,
  73         _PATH_SSH_CLIENT_IDENTITY,
  74         NULL
  75 };
  76
  77 /* Default lifetime (0 == forever) */
  78 static int lifetime = 0;
  79
  80 /* User has to confirm key use */
  81 static int confirm = 0;
  82
  83 /* we keep a cache of one passphrases */
  84 static char *pass = NULL;
  85 static void
  86 clear_pass(void)
  87 {
  88         if (pass) {
  89                 memset(pass, 0, strlen(pass));
  90                 xfree(pass);
  91                 pass = NULL;
  92         }
  93 }
  94
  95 static int
  96 delete_file(AuthenticationConnection *ac, const char *filename)
  97 {
  98         Key *public;
  99         char *comment = NULL;
 100         int ret = -1;
 101
 102         public = key_load_public(filename, &comment);
 103         if (public == NULL) {
 104                 printf("Bad key file %s\n", filename);
 105                 return -1;
 106         }
 107         if (ssh_remove_identity(ac, public)) {
 108                 fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment);
 109                 ret = 0;
 110         } else
 111                 fprintf(stderr, "Could not remove identity: %s\n", filename);
 112
 113         key_free(public);
 114         xfree(comment);
 115
 116         return ret;
 117 }
 118
 119 /* Send a request to remove all identities. */
 120 static int
 121 delete_all(AuthenticationConnection *ac)
 122 {
 123         int ret = -1;
 124
 125         if (ssh_remove_all_identities(ac, 1))
 126                 ret = 0;
 127         /* ignore error-code for ssh2 */
 128         ssh_remove_all_identities(ac, 2);
 129
 130         if (ret == 0)
 131                 fprintf(stderr, "All identities removed.\n");
 132         else
 133                 fprintf(stderr, "Failed to remove all identities.\n");
 134
 135         return ret;
 136 }
 137
 138 static int
 139 add_file(AuthenticationConnection *ac, const char *filename)
 140 {
 141         Key *private, *cert;
 142         char *comment = NULL;
 143         char msg[1024], *certpath;
 144         int fd, perms_ok, ret = -1;
 145
 146         if ((fd = open(filename, O_RDONLY)) < 0) {
 147                 perror(filename);
 148                 return -1;
 149         }
 150
 151         /*
 152          * Since we'll try to load a keyfile multiple times, permission errors
 153          * will occur multiple times, so check perms first and bail if wrong.
 154          */
 155         perms_ok = key_perm_ok(fd, filename);
 156         close(fd);
 157         if (!perms_ok)
 158                 return -1;
 159
 160         /* At first, try empty passphrase */
 161         private = key_load_private(filename, "", &comment);
 162         if (comment == NULL)
 163                 comment = xstrdup(filename);
 164         /* try last */
 165         if (private == NULL && pass != NULL)
 166                 private = key_load_private(filename, pass, NULL);
 167         if (private == NULL) {
 168                 /* clear passphrase since it did not work */
 169                 clear_pass();
 170                 snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ",
 171                     comment);
 172                 for (;;) {
 173                         pass = read_passphrase(msg, RP_ALLOW_STDIN);
 174                         if (strcmp(pass, "") == 0) {
 175                                 clear_pass();
 176                                 xfree(comment);
 177                                 return -1;
 178                         }
 179                         private = key_load_private(filename, pass, &comment);
 180                         if (private != NULL)
 181                                 break;
 182                         clear_pass();
 183                         snprintf(msg, sizeof msg,
 184                             "Bad passphrase, try again for %.200s: ", comment);
 185                 }
 186         }
 187
 188         if (ssh_add_identity_constrained(ac, private, comment, lifetime,
 189             confirm)) {
 190                 fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
 191                 ret = 0;
 192                 if (lifetime != 0)
 193                         fprintf(stderr,
 194                             "Lifetime set to %d seconds\n", lifetime);
 195                 if (confirm != 0)
 196                         fprintf(stderr,
 197                             "The user must confirm each use of the key\n");
 198         } else {
 199                 fprintf(stderr, "Could not add identity: %s\n", filename);
 200         }
 201
 202
 203         /* Now try to add the certificate flavour too */
 204         xasprintf(&certpath, "%s-cert.pub", filename);
 205         if ((cert = key_load_public(certpath, NULL)) == NULL)
 206                 goto out;
 207
 208         if (!key_equal_public(cert, private)) {
 209                 error("Certificate %s does not match private key %s",
 210                     certpath, filename);
 211                 key_free(cert);
 212                 goto out;
 213         }
 214
 215         /* Graft with private bits */
 216         if (key_to_certified(private, key_cert_is_legacy(cert)) != 0) {
 217                 error("%s: key_to_certified failed", __func__);
 218                 key_free(cert);
 219                 goto out;
 220         }
 221         key_cert_copy(cert, private);
 222         key_free(cert);
 223
 224         if (!ssh_add_identity_constrained(ac, private, comment,
 225             lifetime, confirm)) {
 226                 error("Certificate %s (%s) add failed", certpath,
 227                     private->cert->key_id);
 228         }
 229         fprintf(stderr, "Certificate added: %s (%s)\n", certpath,
 230             private->cert->key_id);
 231         if (lifetime != 0)
 232                 fprintf(stderr, "Lifetime set to %d seconds\n", lifetime);
 233         if (confirm != 0)
 234                 fprintf(stderr, "The user must confirm each use of the key\n");
 235  out:
 236         xfree(certpath);
 237         xfree(comment);
 238         key_free(private);
 239
 240         return ret;
 241 }
 242
 243 static int
 244 update_card(AuthenticationConnection *ac, int add, const char *id)
 245 {
 246         char *pin;
 247         int ret = -1;
 248
 249         pin = read_passphrase("Enter passphrase for PKCS#11: ", RP_ALLOW_STDIN);
 250         if (pin == NULL)
 251                 return -1;
 252
 253         if (ssh_update_card(ac, add, id, pin, lifetime, confirm)) {
 254                 fprintf(stderr, "Card %s: %s\n",
 255                     add ? "added" : "removed", id);
 256                 ret = 0;
 257         } else {
 258                 fprintf(stderr, "Could not %s card: %s\n",
 259                     add ? "add" : "remove", id);
 260                 ret = -1;
 261         }
 262         xfree(pin);
 263         return ret;
 264 }
 265
 266 static int
 267 list_identities(AuthenticationConnection *ac, int do_fp)
 268 {
 269         Key *key;
 270         char *comment, *fp;
 271         int had_identities = 0;
 272         int version;
 273
 274         for (version = 1; version <= 2; version++) {
 275                 for (key = ssh_get_first_identity(ac, &comment, version);
 276                     key != NULL;
 277                     key = ssh_get_next_identity(ac, &comment, version)) {
 278                         had_identities = 1;
 279                         if (do_fp) {
 280                                 fp = key_fingerprint(key, SSH_FP_MD5,
 281                                     SSH_FP_HEX);
 282                                 printf("%d %s %s (%s)\n",
 283                                     key_size(key), fp, comment, key_type(key));
 284                                 xfree(fp);
 285                         } else {
 286                                 if (!key_write(key, stdout))
 287                                         fprintf(stderr, "key_write failed");
 288                                 fprintf(stdout, " %s\n", comment);
 289                         }
 290                         key_free(key);
 291                         xfree(comment);
 292                 }
 293         }
 294         if (!had_identities) {
 295                 printf("The agent has no identities.\n");
 296                 return -1;
 297         }
 298         return 0;
 299 }
 300
 301 static int
 302 lock_agent(AuthenticationConnection *ac, int lock)
 303 {
 304         char prompt[100], *p1, *p2;
 305         int passok = 1, ret = -1;
 306
 307         strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
 308         p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
 309         if (lock) {
 310                 strlcpy(prompt, "Again: ", sizeof prompt);
 311                 p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
 312                 if (strcmp(p1, p2) != 0) {
 313                         fprintf(stderr, "Passwords do not match.\n");
 314                         passok = 0;
 315                 }
 316                 memset(p2, 0, strlen(p2));
 317                 xfree(p2);
 318         }
 319         if (passok && ssh_lock_agent(ac, lock, p1)) {
 320                 fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
 321                 ret = 0;
 322         } else
 323                 fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un");
 324         memset(p1, 0, strlen(p1));
 325         xfree(p1);
 326         return (ret);
 327 }
 328
 329 static int
 330 do_file(AuthenticationConnection *ac, int deleting, char *file)
 331 {
 332         if (deleting) {
 333                 if (delete_file(ac, file) == -1)
 334                         return -1;
 335         } else {
 336                 if (add_file(ac, file) == -1)
 337                         return -1;
 338         }
 339         return 0;
 340 }
 341
 342 static void
 343 usage(void)
 344 {
 345         fprintf(stderr, "usage: %s [options] [file ...]\n", __progname);
 346         fprintf(stderr, "Options:\n");
 347         fprintf(stderr, "  -l          List fingerprints of all identities.\n");
 348         fprintf(stderr, "  -L          List public key parameters of all identities.\n");
 349         fprintf(stderr, "  -d          Delete identity.\n");
 350         fprintf(stderr, "  -D          Delete all identities.\n");
 351         fprintf(stderr, "  -x          Lock agent.\n");
 352         fprintf(stderr, "  -X          Unlock agent.\n");
 353         fprintf(stderr, "  -t life     Set lifetime (in seconds) when adding identities.\n");
 354         fprintf(stderr, "  -c          Require confirmation to sign using identities\n");
 355         fprintf(stderr, "  -s pkcs11   Add keys from PKCS#11 provider.\n");
 356         fprintf(stderr, "  -e pkcs11   Remove keys provided by PKCS#11 provider.\n");
 357 }
 358
 359 int
 360 main(int argc, char **argv)
 361 {
 362         extern char *optarg;
 363         extern int optind;
 364         AuthenticationConnection *ac = NULL;
 365         char *pkcs11provider = NULL;
 366         int i, ch, deleting = 0, ret = 0;
 367
 368         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 369         sanitise_stdfd();
 370
 371         __progname = ssh_get_progname(argv[0]);
 372         init_rng();
 373         seed_rng();
 374
 375         SSLeay_add_all_algorithms();
 376
 377         /* At first, get a connection to the authentication agent. */
 378         ac = ssh_get_authentication_connection();
 379         if (ac == NULL) {
 380                 fprintf(stderr,
 381                     "Could not open a connection to your authentication agent.\n");
 382                 exit(2);
 383         }
 384         while ((ch = getopt(argc, argv, "lLcdDxXe:s:t:")) != -1) {
 385                 switch (ch) {
 386                 case 'l':
 387                 case 'L':
 388                         if (list_identities(ac, ch == 'l' ? 1 : 0) == -1)
 389                                 ret = 1;
 390                         goto done;
 391                 case 'x':
 392                 case 'X':
 393                         if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1)
 394                                 ret = 1;
 395                         goto done;
 396                 case 'c':
 397                         confirm = 1;
 398                         break;
 399                 case 'd':
 400                         deleting = 1;
 401                         break;
 402                 case 'D':
 403                         if (delete_all(ac) == -1)
 404                                 ret = 1;
 405                         goto done;
 406                 case 's':
 407                         pkcs11provider = optarg;
 408                         break;
 409                 case 'e':
 410                         deleting = 1;
 411                         pkcs11provider = optarg;
 412                         break;
 413                 case 't':
 414                         if ((lifetime = convtime(optarg)) == -1) {
 415                                 fprintf(stderr, "Invalid lifetime\n");
 416                                 ret = 1;
 417                                 goto done;
 418                         }
 419                         break;
 420                 default:
 421                         usage();
 422                         ret = 1;
 423                         goto done;
 424                 }
 425         }
 426         argc -= optind;
 427         argv += optind;
 428         if (pkcs11provider != NULL) {
 429                 if (update_card(ac, !deleting, pkcs11provider) == -1)
 430                         ret = 1;
 431                 goto done;
 432         }
 433         if (argc == 0) {
 434                 char buf[MAXPATHLEN];
 435                 struct passwd *pw;
 436                 struct stat st;
 437                 int count = 0;
 438
 439                 if ((pw = getpwuid(getuid())) == NULL) {
 440                         fprintf(stderr, "No user found with uid %u\n",
 441                             (u_int)getuid());
 442                         ret = 1;
 443                         goto done;
 444                 }
 445
 446                 for (i = 0; default_files[i]; i++) {
 447                         snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
 448                             default_files[i]);
 449                         if (stat(buf, &st) < 0)
 450                                 continue;
 451                         if (do_file(ac, deleting, buf) == -1)
 452                                 ret = 1;
 453                         else
 454                                 count++;
 455                 }
 456                 if (count == 0)
 457                         ret = 1;
 458         } else {
 459                 for (i = 0; i < argc; i++) {
 460                         if (do_file(ac, deleting, argv[i]) == -1)
 461                                 ret = 1;
 462                 }
 463         }
 464         clear_pass();
 465
 466 done:
 467         ssh_close_authentication_connection(ac);
 468         return ret;
 469 }