ssh-add.c

   1 /* $OpenBSD: ssh-add.c,v 1.173 2024/09/06 02:30:44 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
  43 #ifdef WITH_OPENSSL
  44 # include <openssl/evp.h>
  45 # include "openbsd-compat/openssl-compat.h"
  46 #endif
  47
  48 #include <errno.h>
  49 #include <fcntl.h>
  50 #include <pwd.h>
  51 #include <stdarg.h>
  52 #include <stdio.h>
  53 #include <stdlib.h>
  54 #include <string.h>
  55 #include <unistd.h>
  56 #include <limits.h>
  57
  58 #include "xmalloc.h"
  59 #include "ssh.h"
  60 #include "log.h"
  61 #include "sshkey.h"
  62 #include "sshbuf.h"
  63 #include "authfd.h"
  64 #include "authfile.h"
  65 #include "pathnames.h"
  66 #include "misc.h"
  67 #include "ssherr.h"
  68 #include "digest.h"
  69 #include "ssh-sk.h"
  70 #include "sk-api.h"
  71 #include "hostfile.h"
  72
  73 /* argv0 */
  74 extern char *__progname;
  75
  76 /* Default files to add */
  77 static char *default_files[] = {
  78 #ifdef WITH_OPENSSL
  79         _PATH_SSH_CLIENT_ID_RSA,
  80 #ifdef OPENSSL_HAS_ECC
  81         _PATH_SSH_CLIENT_ID_ECDSA,
  82         _PATH_SSH_CLIENT_ID_ECDSA_SK,
  83 #endif
  84 #endif /* WITH_OPENSSL */
  85         _PATH_SSH_CLIENT_ID_ED25519,
  86         _PATH_SSH_CLIENT_ID_ED25519_SK,
  87         _PATH_SSH_CLIENT_ID_XMSS,
  88 #ifdef WITH_DSA
  89         _PATH_SSH_CLIENT_ID_DSA,
  90 #endif
  91         NULL
  92 };
  93
  94 static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
  95
  96 /* Default lifetime (0 == forever) */
  97 static int lifetime = 0;
  98
  99 /* User has to confirm key use */
 100 static int confirm = 0;
 101
 102 /* Maximum number of signatures (XMSS) */
 103 static u_int maxsign = 0;
 104 static u_int minleft = 0;
 105
 106 /* we keep a cache of one passphrase */
 107 static char *pass = NULL;
 108 static void
 109 clear_pass(void)
 110 {
 111         if (pass) {
 112                 freezero(pass, strlen(pass));
 113                 pass = NULL;
 114         }
 115 }
 116
 117 static int
 118 delete_one(int agent_fd, const struct sshkey *key, const char *comment,
 119     const char *path, int qflag)
 120 {
 121         int r;
 122
 123         if ((r = ssh_remove_identity(agent_fd, key)) != 0) {
 124                 fprintf(stderr, "Could not remove identity \"%s\": %s\n",
 125                     path, ssh_err(r));
 126                 return r;
 127         }
 128         if (!qflag) {
 129                 fprintf(stderr, "Identity removed: %s %s (%s)\n", path,
 130                     sshkey_type(key), comment ? comment : "no comment");
 131         }
 132         return 0;
 133 }
 134
 135 static int
 136 delete_stdin(int agent_fd, int qflag, int key_only, int cert_only)
 137 {
 138         char *line = NULL, *cp;
 139         size_t linesize = 0;
 140         struct sshkey *key = NULL;
 141         int lnum = 0, r, ret = -1;
 142
 143         while (getline(&line, &linesize, stdin) != -1) {
 144                 lnum++;
 145                 sshkey_free(key);
 146                 key = NULL;
 147                 line[strcspn(line, "\n")] = '\0';
 148                 cp = line + strspn(line, " \t");
 149                 if (*cp == '#' || *cp == '\0')
 150                         continue;
 151                 if ((key = sshkey_new(KEY_UNSPEC)) == NULL)
 152                         fatal_f("sshkey_new");
 153                 if ((r = sshkey_read(key, &cp)) != 0) {
 154                         error_r(r, "(stdin):%d: invalid key", lnum);
 155                         continue;
 156                 }
 157                 if ((!key_only && !cert_only) ||
 158                     (key_only && !sshkey_is_cert(key)) ||
 159                     (cert_only && sshkey_is_cert(key))) {
 160                         if (delete_one(agent_fd, key, cp,
 161                             "(stdin)", qflag) == 0)
 162                                 ret = 0;
 163                 }
 164         }
 165         sshkey_free(key);
 166         free(line);
 167         return ret;
 168 }
 169
 170 static int
 171 delete_file(int agent_fd, const char *filename, int key_only,
 172     int cert_only, int qflag)
 173 {
 174         struct sshkey *public, *cert = NULL;
 175         char *certpath = NULL, *comment = NULL;
 176         int r, ret = -1;
 177
 178         if (strcmp(filename, "-") == 0)
 179                 return delete_stdin(agent_fd, qflag, key_only, cert_only);
 180
 181         if ((r = sshkey_load_public(filename, &public,  &comment)) != 0) {
 182                 printf("Bad key file %s: %s\n", filename, ssh_err(r));
 183                 return -1;
 184         }
 185         if ((!key_only && !cert_only) ||
 186             (key_only && !sshkey_is_cert(public)) ||
 187             (cert_only && sshkey_is_cert(public))) {
 188                 if (delete_one(agent_fd, public, comment, filename, qflag) == 0)
 189                         ret = 0;
 190         }
 191
 192         if (key_only)
 193                 goto out;
 194
 195         /* Now try to delete the corresponding certificate too */
 196         free(comment);
 197         comment = NULL;
 198         xasprintf(&certpath, "%s-cert.pub", filename);
 199         if ((r = sshkey_load_public(certpath, &cert, &comment)) != 0) {
 200                 if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT)
 201                         error_r(r, "Failed to load certificate \"%s\"", certpath);
 202                 goto out;
 203         }
 204
 205         if (!sshkey_equal_public(cert, public))
 206                 fatal("Certificate %s does not match private key %s",
 207                     certpath, filename);
 208
 209         if (delete_one(agent_fd, cert, comment, certpath, qflag) == 0)
 210                 ret = 0;
 211
 212  out:
 213         sshkey_free(cert);
 214         sshkey_free(public);
 215         free(certpath);
 216         free(comment);
 217
 218         return ret;
 219 }
 220
 221 /* Send a request to remove all identities. */
 222 static int
 223 delete_all(int agent_fd, int qflag)
 224 {
 225         int ret = -1;
 226
 227         /*
 228          * Since the agent might be forwarded, old or non-OpenSSH, when asked
 229          * to remove all keys, attempt to remove both protocol v.1 and v.2
 230          * keys.
 231          */
 232         if (ssh_remove_all_identities(agent_fd, 2) == 0)
 233                 ret = 0;
 234         /* ignore error-code for ssh1 */
 235         ssh_remove_all_identities(agent_fd, 1);
 236
 237         if (ret != 0)
 238                 fprintf(stderr, "Failed to remove all identities.\n");
 239         else if (!qflag)
 240                 fprintf(stderr, "All identities removed.\n");
 241
 242         return ret;
 243 }
 244
 245 static int
 246 add_file(int agent_fd, const char *filename, int key_only, int cert_only,
 247     int qflag, const char *skprovider,
 248     struct dest_constraint **dest_constraints,
 249     size_t ndest_constraints)
 250 {
 251         struct sshkey *private, *cert;
 252         char *comment = NULL;
 253         char msg[1024], *certpath = NULL;
 254         int r, fd, ret = -1;
 255         size_t i;
 256         u_int32_t left;
 257         struct sshbuf *keyblob;
 258         struct ssh_identitylist *idlist;
 259
 260         if (strcmp(filename, "-") == 0) {
 261                 fd = STDIN_FILENO;
 262                 filename = "(stdin)";
 263         } else if ((fd = open(filename, O_RDONLY)) == -1) {
 264                 perror(filename);
 265                 return -1;
 266         }
 267
 268         /*
 269          * Since we'll try to load a keyfile multiple times, permission errors
 270          * will occur multiple times, so check perms first and bail if wrong.
 271          */
 272         if (fd != STDIN_FILENO) {
 273                 if (sshkey_perm_ok(fd, filename) != 0) {
 274                         close(fd);
 275                         return -1;
 276                 }
 277         }
 278         if ((r = sshbuf_load_fd(fd, &keyblob)) != 0) {
 279                 fprintf(stderr, "Error loading key \"%s\": %s\n",
 280                     filename, ssh_err(r));
 281                 sshbuf_free(keyblob);
 282                 close(fd);
 283                 return -1;
 284         }
 285         close(fd);
 286
 287         /* At first, try empty passphrase */
 288         if ((r = sshkey_parse_private_fileblob(keyblob, "", &private,
 289             &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
 290                 fprintf(stderr, "Error loading key \"%s\": %s\n",
 291                     filename, ssh_err(r));
 292                 goto fail_load;
 293         }
 294         /* try last */
 295         if (private == NULL && pass != NULL) {
 296                 if ((r = sshkey_parse_private_fileblob(keyblob, pass, &private,
 297                     &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
 298                         fprintf(stderr, "Error loading key \"%s\": %s\n",
 299                             filename, ssh_err(r));
 300                         goto fail_load;
 301                 }
 302         }
 303         if (private == NULL) {
 304                 /* clear passphrase since it did not work */
 305                 clear_pass();
 306                 snprintf(msg, sizeof msg, "Enter passphrase for %s%s: ",
 307                     filename, confirm ? " (will confirm each use)" : "");
 308                 for (;;) {
 309                         pass = read_passphrase(msg, RP_ALLOW_STDIN);
 310                         if (strcmp(pass, "") == 0)
 311                                 goto fail_load;
 312                         if ((r = sshkey_parse_private_fileblob(keyblob, pass,
 313                             &private, &comment)) == 0)
 314                                 break;
 315                         else if (r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
 316                                 fprintf(stderr,
 317                                     "Error loading key \"%s\": %s\n",
 318                                     filename, ssh_err(r));
 319  fail_load:
 320                                 clear_pass();
 321                                 sshbuf_free(keyblob);
 322                                 return -1;
 323                         }
 324                         clear_pass();
 325                         snprintf(msg, sizeof msg,
 326                             "Bad passphrase, try again for %s%s: ", filename,
 327                             confirm ? " (will confirm each use)" : "");
 328                 }
 329         }
 330         if (comment == NULL || *comment == '\0')
 331                 comment = xstrdup(filename);
 332         sshbuf_free(keyblob);
 333
 334         /* For XMSS */
 335         if ((r = sshkey_set_filename(private, filename)) != 0) {
 336                 fprintf(stderr, "Could not add filename to private key: %s (%s)\n",
 337                     filename, comment);
 338                 goto out;
 339         }
 340         if (maxsign && minleft &&
 341             (r = ssh_fetch_identitylist(agent_fd, &idlist)) == 0) {
 342                 for (i = 0; i < idlist->nkeys; i++) {
 343                         if (!sshkey_equal_public(idlist->keys[i], private))
 344                                 continue;
 345                         left = sshkey_signatures_left(idlist->keys[i]);
 346                         if (left < minleft) {
 347                                 fprintf(stderr,
 348                                     "Only %d signatures left.\n", left);
 349                                 break;
 350                         }
 351                         fprintf(stderr, "Skipping update: ");
 352                         if (left == minleft) {
 353                                 fprintf(stderr,
 354                                     "required signatures left (%d).\n", left);
 355                         } else {
 356                                 fprintf(stderr,
 357                                     "more signatures left (%d) than"
 358                                     " required (%d).\n", left, minleft);
 359                         }
 360                         ssh_free_identitylist(idlist);
 361                         goto out;
 362                 }
 363                 ssh_free_identitylist(idlist);
 364         }
 365
 366         if (sshkey_is_sk(private)) {
 367                 if (skprovider == NULL) {
 368                         fprintf(stderr, "Cannot load FIDO key %s "
 369                             "without provider\n", filename);
 370                         goto out;
 371                 }
 372         } else {
 373                 /* Don't send provider constraint for other keys */
 374                 skprovider = NULL;
 375         }
 376
 377         if (!cert_only &&
 378             (r = ssh_add_identity_constrained(agent_fd, private, comment,
 379             lifetime, confirm, maxsign, skprovider,
 380             dest_constraints, ndest_constraints)) == 0) {
 381                 ret = 0;
 382                 if (!qflag) {
 383                         fprintf(stderr, "Identity added: %s (%s)\n",
 384                             filename, comment);
 385                         if (lifetime != 0) {
 386                                 fprintf(stderr,
 387                                     "Lifetime set to %d seconds\n", lifetime);
 388                         }
 389                         if (confirm != 0) {
 390                                 fprintf(stderr, "The user must confirm "
 391                                     "each use of the key\n");
 392                         }
 393                 }
 394         } else {
 395                 fprintf(stderr, "Could not add identity \"%s\": %s\n",
 396                     filename, ssh_err(r));
 397         }
 398
 399         /* Skip trying to load the cert if requested */
 400         if (key_only)
 401                 goto out;
 402
 403         /* Now try to add the certificate flavour too */
 404         xasprintf(&certpath, "%s-cert.pub", filename);
 405         if ((r = sshkey_load_public(certpath, &cert, NULL)) != 0) {
 406                 if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT)
 407                         error_r(r, "Failed to load certificate \"%s\"",
 408                             certpath);
 409                 goto out;
 410         }
 411
 412         if (!sshkey_equal_public(cert, private)) {
 413                 error("Certificate %s does not match private key %s",
 414                     certpath, filename);
 415                 sshkey_free(cert);
 416                 goto out;
 417         }
 418
 419         /* Graft with private bits */
 420         if ((r = sshkey_to_certified(private)) != 0) {
 421                 error_fr(r, "sshkey_to_certified");
 422                 sshkey_free(cert);
 423                 goto out;
 424         }
 425         if ((r = sshkey_cert_copy(cert, private)) != 0) {
 426                 error_fr(r, "sshkey_cert_copy");
 427                 sshkey_free(cert);
 428                 goto out;
 429         }
 430         sshkey_free(cert);
 431
 432         if ((r = ssh_add_identity_constrained(agent_fd, private, comment,
 433             lifetime, confirm, maxsign, skprovider,
 434             dest_constraints, ndest_constraints)) != 0) {
 435                 error_r(r, "Certificate %s (%s) add failed", certpath,
 436                     private->cert->key_id);
 437                 goto out;
 438         }
 439         /* success */
 440         if (!qflag) {
 441                 fprintf(stderr, "Certificate added: %s (%s)\n", certpath,
 442                     private->cert->key_id);
 443                 if (lifetime != 0) {
 444                         fprintf(stderr, "Lifetime set to %d seconds\n",
 445                             lifetime);
 446                 }
 447                 if (confirm != 0) {
 448                         fprintf(stderr, "The user must confirm each use "
 449                             "of the key\n");
 450                 }
 451         }
 452
 453  out:
 454         free(certpath);
 455         free(comment);
 456         sshkey_free(private);
 457
 458         return ret;
 459 }
 460
 461 static int
 462 update_card(int agent_fd, int add, const char *id, int qflag,
 463     int key_only, int cert_only,
 464     struct dest_constraint **dest_constraints, size_t ndest_constraints,
 465     struct sshkey **certs, size_t ncerts)
 466 {
 467         char *pin = NULL;
 468         int r, ret = -1;
 469
 470         if (key_only)
 471                 ncerts = 0;
 472
 473         if (add) {
 474                 if ((pin = read_passphrase("Enter passphrase for PKCS#11: ",
 475                     RP_ALLOW_STDIN)) == NULL)
 476                         return -1;
 477         }
 478
 479         if ((r = ssh_update_card(agent_fd, add, id, pin == NULL ? "" : pin,
 480             lifetime, confirm, dest_constraints, ndest_constraints,
 481             cert_only, certs, ncerts)) == 0) {
 482                 ret = 0;
 483                 if (!qflag) {
 484                         fprintf(stderr, "Card %s: %s\n",
 485                             add ? "added" : "removed", id);
 486                 }
 487         } else {
 488                 fprintf(stderr, "Could not %s card \"%s\": %s\n",
 489                     add ? "add" : "remove", id, ssh_err(r));
 490                 ret = -1;
 491         }
 492         free(pin);
 493         return ret;
 494 }
 495
 496 static int
 497 test_key(int agent_fd, const char *filename)
 498 {
 499         struct sshkey *key = NULL;
 500         u_char *sig = NULL;
 501         const char *alg = NULL;
 502         size_t slen = 0;
 503         int r, ret = -1;
 504         char data[1024];
 505
 506         if ((r = sshkey_load_public(filename, &key, NULL)) != 0) {
 507                 error_r(r, "Couldn't read public key %s", filename);
 508                 return -1;
 509         }
 510         if (sshkey_type_plain(key->type) == KEY_RSA)
 511                 alg = "rsa-sha2-256";
 512         arc4random_buf(data, sizeof(data));
 513         if ((r = ssh_agent_sign(agent_fd, key, &sig, &slen, data, sizeof(data),
 514             alg, 0)) != 0) {
 515                 error_r(r, "Agent signature failed for %s", filename);
 516                 goto done;
 517         }
 518         if ((r = sshkey_verify(key, sig, slen, data, sizeof(data),
 519             alg, 0, NULL)) != 0) {
 520                 error_r(r, "Signature verification failed for %s", filename);
 521                 goto done;
 522         }
 523         /* success */
 524         ret = 0;
 525  done:
 526         free(sig);
 527         sshkey_free(key);
 528         return ret;
 529 }
 530
 531 static int
 532 list_identities(int agent_fd, int do_fp)
 533 {
 534         char *fp;
 535         int r;
 536         struct ssh_identitylist *idlist;
 537         u_int32_t left;
 538         size_t i;
 539
 540         if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
 541                 if (r != SSH_ERR_AGENT_NO_IDENTITIES)
 542                         fprintf(stderr, "error fetching identities: %s\n",
 543                             ssh_err(r));
 544                 else
 545                         printf("The agent has no identities.\n");
 546                 return -1;
 547         }
 548         for (i = 0; i < idlist->nkeys; i++) {
 549                 if (do_fp) {
 550                         fp = sshkey_fingerprint(idlist->keys[i],
 551                             fingerprint_hash, SSH_FP_DEFAULT);
 552                         printf("%u %s %s (%s)\n", sshkey_size(idlist->keys[i]),
 553                             fp == NULL ? "(null)" : fp, idlist->comments[i],
 554                             sshkey_type(idlist->keys[i]));
 555                         free(fp);
 556                 } else {
 557                         if ((r = sshkey_write(idlist->keys[i], stdout)) != 0) {
 558                                 fprintf(stderr, "sshkey_write: %s\n",
 559                                     ssh_err(r));
 560                                 continue;
 561                         }
 562                         fprintf(stdout, " %s", idlist->comments[i]);
 563                         left = sshkey_signatures_left(idlist->keys[i]);
 564                         if (left > 0)
 565                                 fprintf(stdout,
 566                                     " [signatures left %d]", left);
 567                         fprintf(stdout, "\n");
 568                 }
 569         }
 570         ssh_free_identitylist(idlist);
 571         return 0;
 572 }
 573
 574 static int
 575 lock_agent(int agent_fd, int lock)
 576 {
 577         char prompt[100], *p1, *p2;
 578         int r, passok = 1, ret = -1;
 579
 580         strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
 581         p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
 582         if (lock) {
 583                 strlcpy(prompt, "Again: ", sizeof prompt);
 584                 p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
 585                 if (strcmp(p1, p2) != 0) {
 586                         fprintf(stderr, "Passwords do not match.\n");
 587                         passok = 0;
 588                 }
 589                 freezero(p2, strlen(p2));
 590         }
 591         if (passok) {
 592                 if ((r = ssh_lock_agent(agent_fd, lock, p1)) == 0) {
 593                         fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
 594                         ret = 0;
 595                 } else {
 596                         fprintf(stderr, "Failed to %slock agent: %s\n",
 597                             lock ? "" : "un", ssh_err(r));
 598                 }
 599         }
 600         freezero(p1, strlen(p1));
 601         return (ret);
 602 }
 603
 604 static int
 605 load_resident_keys(int agent_fd, const char *skprovider, int qflag,
 606     struct dest_constraint **dest_constraints, size_t ndest_constraints)
 607 {
 608         struct sshsk_resident_key **srks;
 609         size_t nsrks, i;
 610         struct sshkey *key;
 611         int r, ok = 0;
 612         char *fp;
 613
 614         pass = read_passphrase("Enter PIN for authenticator: ", RP_ALLOW_STDIN);
 615         if ((r = sshsk_load_resident(skprovider, NULL, pass, 0,
 616             &srks, &nsrks)) != 0) {
 617                 error_r(r, "Unable to load resident keys");
 618                 return r;
 619         }
 620         for (i = 0; i < nsrks; i++) {
 621                 key = srks[i]->key;
 622                 if ((fp = sshkey_fingerprint(key,
 623                     fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
 624                         fatal_f("sshkey_fingerprint failed");
 625                 if ((r = ssh_add_identity_constrained(agent_fd, key, "",
 626                     lifetime, confirm, maxsign, skprovider,
 627                     dest_constraints, ndest_constraints)) != 0) {
 628                         error("Unable to add key %s %s",
 629                             sshkey_type(key), fp);
 630                         free(fp);
 631                         ok = r;
 632                         continue;
 633                 }
 634                 if (ok == 0)
 635                         ok = 1;
 636                 if (!qflag) {
 637                         fprintf(stderr, "Resident identity added: %s %s\n",
 638                             sshkey_type(key), fp);
 639                         if (lifetime != 0) {
 640                                 fprintf(stderr,
 641                                     "Lifetime set to %d seconds\n", lifetime);
 642                         }
 643                         if (confirm != 0) {
 644                                 fprintf(stderr, "The user must confirm "
 645                                     "each use of the key\n");
 646                         }
 647                 }
 648                 free(fp);
 649         }
 650         sshsk_free_resident_keys(srks, nsrks);
 651         if (nsrks == 0)
 652                 return SSH_ERR_KEY_NOT_FOUND;
 653         return ok == 1 ? 0 : ok;
 654 }
 655
 656 static int
 657 do_file(int agent_fd, int deleting, int key_only, int cert_only,
 658     char *file, int qflag, const char *skprovider,
 659     struct dest_constraint **dest_constraints, size_t ndest_constraints)
 660 {
 661         if (deleting) {
 662                 if (delete_file(agent_fd, file, key_only,
 663                     cert_only, qflag) == -1)
 664                         return -1;
 665         } else {
 666                 if (add_file(agent_fd, file, key_only, cert_only, qflag,
 667                     skprovider, dest_constraints, ndest_constraints) == -1)
 668                         return -1;
 669         }
 670         return 0;
 671 }
 672
 673 /* Append string 's' to a NULL-terminated array of strings */
 674 static void
 675 stringlist_append(char ***listp, const char *s)
 676 {
 677         size_t i = 0;
 678
 679         if (*listp == NULL)
 680                 *listp = xcalloc(2, sizeof(**listp));
 681         else {
 682                 for (i = 0; (*listp)[i] != NULL; i++)
 683                         ; /* count */
 684                 *listp = xrecallocarray(*listp, i + 1, i + 2, sizeof(**listp));
 685         }
 686         (*listp)[i] = xstrdup(s);
 687 }
 688
 689 static void
 690 parse_dest_constraint_hop(const char *s, struct dest_constraint_hop *dch,
 691     char **hostkey_files)
 692 {
 693         char *user = NULL, *host, *os, *path;
 694         size_t i;
 695         struct hostkeys *hostkeys;
 696         const struct hostkey_entry *hke;
 697         int r, want_ca;
 698
 699         memset(dch, '\0', sizeof(*dch));
 700         os = xstrdup(s);
 701         if ((host = strrchr(os, '@')) == NULL)
 702                 host = os;
 703         else {
 704                 *host++ = '\0';
 705                 user = os;
 706         }
 707         cleanhostname(host);
 708         /* Trivial case: username@ (all hosts) */
 709         if (*host == '\0') {
 710                 if (user == NULL) {
 711                         fatal("Invalid key destination constraint \"%s\": "
 712                             "does not specify user or host", s);
 713                 }
 714                 dch->user = xstrdup(user);
 715                 /* other fields left blank */
 716                 free(os);
 717                 return;
 718         }
 719         if (hostkey_files == NULL)
 720                 fatal_f("no hostkey files");
 721         /* Otherwise we need to look up the keys for this hostname */
 722         hostkeys = init_hostkeys();
 723         for (i = 0; hostkey_files[i]; i++) {
 724                 path = tilde_expand_filename(hostkey_files[i], getuid());
 725                 debug2_f("looking up host keys for \"%s\" in %s", host, path);
 726                 load_hostkeys(hostkeys, host, path, 0);
 727                 free(path);
 728         }
 729         dch->user = user == NULL ? NULL : xstrdup(user);
 730         dch->hostname = xstrdup(host);
 731         for (i = 0; i < hostkeys->num_entries; i++) {
 732                 hke = hostkeys->entries + i;
 733                 want_ca = hke->marker == MRK_CA;
 734                 if (hke->marker != MRK_NONE && !want_ca)
 735                         continue;
 736                 debug3_f("%s%s%s: adding %s %skey from %s:%lu as key %u",
 737                     user == NULL ? "": user, user == NULL ? "" : "@",
 738                     host, sshkey_type(hke->key), want_ca ? "CA " : "",
 739                     hke->file, hke->line, dch->nkeys);
 740                 dch->keys = xrecallocarray(dch->keys, dch->nkeys,
 741                     dch->nkeys + 1, sizeof(*dch->keys));
 742                 dch->key_is_ca = xrecallocarray(dch->key_is_ca, dch->nkeys,
 743                     dch->nkeys + 1, sizeof(*dch->key_is_ca));
 744                 if ((r = sshkey_from_private(hke->key,
 745                     &(dch->keys[dch->nkeys]))) != 0)
 746                         fatal_fr(r, "sshkey_from_private");
 747                 dch->key_is_ca[dch->nkeys] = want_ca;
 748                 dch->nkeys++;
 749         }
 750         if (dch->nkeys == 0)
 751                 fatal("No host keys found for destination \"%s\"", host);
 752         free_hostkeys(hostkeys);
 753         free(os);
 754         return;
 755 }
 756
 757 static void
 758 parse_dest_constraint(const char *s, struct dest_constraint ***dcp,
 759     size_t *ndcp, char **hostkey_files)
 760 {
 761         struct dest_constraint *dc;
 762         char *os, *cp;
 763
 764         dc = xcalloc(1, sizeof(*dc));
 765         os = xstrdup(s);
 766         if ((cp = strchr(os, '>')) == NULL) {
 767                 /* initial hop; no 'from' hop specified */
 768                 parse_dest_constraint_hop(os, &dc->to, hostkey_files);
 769         } else {
 770                 /* two hops specified */
 771                 *(cp++) = '\0';
 772                 parse_dest_constraint_hop(os, &dc->from, hostkey_files);
 773                 parse_dest_constraint_hop(cp, &dc->to, hostkey_files);
 774                 if (dc->from.user != NULL) {
 775                         fatal("Invalid key constraint %s: cannot specify "
 776                             "user on 'from' host", os);
 777                 }
 778         }
 779         /* XXX eliminate or error on duplicates */
 780         debug2_f("constraint %zu: %s%s%s (%u keys) > %s%s%s (%u keys)", *ndcp,
 781             dc->from.user ? dc->from.user : "", dc->from.user ? "@" : "",
 782             dc->from.hostname ? dc->from.hostname : "(ORIGIN)", dc->from.nkeys,
 783             dc->to.user ? dc->to.user : "", dc->to.user ? "@" : "",
 784             dc->to.hostname ? dc->to.hostname : "(ANY)", dc->to.nkeys);
 785         *dcp = xrecallocarray(*dcp, *ndcp, *ndcp + 1, sizeof(**dcp));
 786         (*dcp)[(*ndcp)++] = dc;
 787         free(os);
 788 }
 789
 790
 791 static void
 792 usage(void)
 793 {
 794         fprintf(stderr,
 795 "usage: ssh-add [-CcDdKkLlqvXx] [-E fingerprint_hash] [-H hostkey_file]\n"
 796 "               [-h destination_constraint] [-S provider] [-t life]\n"
 797 #ifdef WITH_XMSS
 798 "               [-M maxsign] [-m minleft]\n"
 799 #endif
 800 "               [file ...]\n"
 801 "       ssh-add -s pkcs11 [-Cv] [certificate ...]\n"
 802 "       ssh-add -e pkcs11\n"
 803 "       ssh-add -T pubkey ...\n"
 804         );
 805 }
 806
 807 int
 808 main(int argc, char **argv)
 809 {
 810         extern char *optarg;
 811         extern int optind;
 812         int agent_fd;
 813         char *pkcs11provider = NULL, *skprovider = NULL;
 814         char **dest_constraint_strings = NULL, **hostkey_files = NULL;
 815         int r, i, ch, deleting = 0, ret = 0, key_only = 0, cert_only = 0;
 816         int do_download = 0, xflag = 0, lflag = 0, Dflag = 0;
 817         int qflag = 0, Tflag = 0;
 818         SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
 819         LogLevel log_level = SYSLOG_LEVEL_INFO;
 820         struct sshkey *k, **certs = NULL;
 821         struct dest_constraint **dest_constraints = NULL;
 822         size_t ndest_constraints = 0, ncerts = 0;
 823
 824         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 825         sanitise_stdfd();
 826
 827         __progname = ssh_get_progname(argv[0]);
 828         seed_rng();
 829
 830         log_init(__progname, log_level, log_facility, 1);
 831
 832         setvbuf(stdout, NULL, _IOLBF, 0);
 833
 834         /* First, get a connection to the authentication agent. */
 835         switch (r = ssh_get_authentication_socket(&agent_fd)) {
 836         case 0:
 837                 break;
 838         case SSH_ERR_AGENT_NOT_PRESENT:
 839                 fprintf(stderr, "Could not open a connection to your "
 840                     "authentication agent.\n");
 841                 exit(2);
 842         default:
 843                 fprintf(stderr, "Error connecting to agent: %s\n", ssh_err(r));
 844                 exit(2);
 845         }
 846
 847         skprovider = getenv("SSH_SK_PROVIDER");
 848
 849         while ((ch = getopt(argc, argv, "vkKlLCcdDTxXE:e:h:H:M:m:qs:S:t:")) != -1) {
 850                 switch (ch) {
 851                 case 'v':
 852                         if (log_level == SYSLOG_LEVEL_INFO)
 853                                 log_level = SYSLOG_LEVEL_DEBUG1;
 854                         else if (log_level < SYSLOG_LEVEL_DEBUG3)
 855                                 log_level++;
 856                         break;
 857                 case 'E':
 858                         fingerprint_hash = ssh_digest_alg_by_name(optarg);
 859                         if (fingerprint_hash == -1)
 860                                 fatal("Invalid hash algorithm \"%s\"", optarg);
 861                         break;
 862                 case 'H':
 863                         stringlist_append(&hostkey_files, optarg);
 864                         break;
 865                 case 'h':
 866                         stringlist_append(&dest_constraint_strings, optarg);
 867                         break;
 868                 case 'k':
 869                         key_only = 1;
 870                         break;
 871                 case 'C':
 872                         cert_only = 1;
 873                         break;
 874                 case 'K':
 875                         do_download = 1;
 876                         break;
 877                 case 'l':
 878                 case 'L':
 879                         if (lflag != 0)
 880                                 fatal("-%c flag already specified", lflag);
 881                         lflag = ch;
 882                         break;
 883                 case 'x':
 884                 case 'X':
 885                         if (xflag != 0)
 886                                 fatal("-%c flag already specified", xflag);
 887                         xflag = ch;
 888                         break;
 889                 case 'c':
 890                         confirm = 1;
 891                         break;
 892                 case 'm':
 893                         minleft = (u_int)strtonum(optarg, 1, UINT_MAX, NULL);
 894                         if (minleft == 0) {
 895                                 usage();
 896                                 ret = 1;
 897                                 goto done;
 898                         }
 899                         break;
 900                 case 'M':
 901                         maxsign = (u_int)strtonum(optarg, 1, UINT_MAX, NULL);
 902                         if (maxsign == 0) {
 903                                 usage();
 904                                 ret = 1;
 905                                 goto done;
 906                         }
 907                         break;
 908                 case 'd':
 909                         deleting = 1;
 910                         break;
 911                 case 'D':
 912                         Dflag = 1;
 913                         break;
 914                 case 's':
 915                         pkcs11provider = optarg;
 916                         break;
 917                 case 'S':
 918                         skprovider = optarg;
 919                         break;
 920                 case 'e':
 921                         deleting = 1;
 922                         pkcs11provider = optarg;
 923                         break;
 924                 case 't':
 925                         if ((lifetime = convtime(optarg)) == -1 ||
 926                             lifetime < 0 || (u_long)lifetime > UINT32_MAX) {
 927                                 fprintf(stderr, "Invalid lifetime\n");
 928                                 ret = 1;
 929                                 goto done;
 930                         }
 931                         break;
 932                 case 'q':
 933                         qflag = 1;
 934                         break;
 935                 case 'T':
 936                         Tflag = 1;
 937                         break;
 938                 default:
 939                         usage();
 940                         ret = 1;
 941                         goto done;
 942                 }
 943         }
 944         log_init(__progname, log_level, log_facility, 1);
 945
 946         if ((xflag != 0) + (lflag != 0) + (Dflag != 0) > 1)
 947                 fatal("Invalid combination of actions");
 948         else if (xflag) {
 949                 if (lock_agent(agent_fd, xflag == 'x' ? 1 : 0) == -1)
 950                         ret = 1;
 951                 goto done;
 952         } else if (lflag) {
 953                 if (list_identities(agent_fd, lflag == 'l' ? 1 : 0) == -1)
 954                         ret = 1;
 955                 goto done;
 956         } else if (Dflag) {
 957                 if (delete_all(agent_fd, qflag) == -1)
 958                         ret = 1;
 959                 goto done;
 960         }
 961
 962 #ifdef ENABLE_SK_INTERNAL
 963         if (skprovider == NULL)
 964                 skprovider = "internal";
 965 #endif
 966
 967         if (hostkey_files == NULL) {
 968                 /* use defaults from readconf.c */
 969                 stringlist_append(&hostkey_files, _PATH_SSH_USER_HOSTFILE);
 970                 stringlist_append(&hostkey_files, _PATH_SSH_USER_HOSTFILE2);
 971                 stringlist_append(&hostkey_files, _PATH_SSH_SYSTEM_HOSTFILE);
 972                 stringlist_append(&hostkey_files, _PATH_SSH_SYSTEM_HOSTFILE2);
 973         }
 974         if (dest_constraint_strings != NULL) {
 975                 for (i = 0; dest_constraint_strings[i] != NULL; i++) {
 976                         parse_dest_constraint(dest_constraint_strings[i],
 977                           &dest_constraints, &ndest_constraints, hostkey_files);
 978                 }
 979         }
 980
 981         argc -= optind;
 982         argv += optind;
 983         if (Tflag) {
 984                 if (argc <= 0)
 985                         fatal("no keys to test");
 986                 for (r = i = 0; i < argc; i++)
 987                         r |= test_key(agent_fd, argv[i]);
 988                 ret = r == 0 ? 0 : 1;
 989                 goto done;
 990         }
 991         if (pkcs11provider != NULL) {
 992                 for (i = 0; i < argc; i++) {
 993                         if ((r = sshkey_load_public(argv[i], &k, NULL)) != 0)
 994                                 fatal_fr(r, "load certificate %s", argv[i]);
 995                         certs = xrecallocarray(certs, ncerts, ncerts + 1,
 996                             sizeof(*certs));
 997                         debug2("%s: %s", argv[i], sshkey_ssh_name(k));
 998                         certs[ncerts++] = k;
 999                 }
1000                 debug2_f("loaded %zu certificates", ncerts);
1001                 if (update_card(agent_fd, !deleting, pkcs11provider,
1002                     qflag, key_only, cert_only,
1003                     dest_constraints, ndest_constraints,
1004                     certs, ncerts) == -1)
1005                         ret = 1;
1006                 goto done;
1007         }
1008         if (do_download) {
1009                 if (skprovider == NULL)
1010                         fatal("Cannot download keys without provider");
1011                 if (load_resident_keys(agent_fd, skprovider, qflag,
1012                     dest_constraints, ndest_constraints) != 0)
1013                         ret = 1;
1014                 goto done;
1015         }
1016         if (argc == 0) {
1017                 char buf[PATH_MAX];
1018                 struct passwd *pw;
1019                 struct stat st;
1020                 int count = 0;
1021
1022                 if ((pw = getpwuid(getuid())) == NULL) {
1023                         fprintf(stderr, "No user found with uid %u\n",
1024                             (u_int)getuid());
1025                         ret = 1;
1026                         goto done;
1027                 }
1028
1029                 for (i = 0; default_files[i]; i++) {
1030                         snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
1031                             default_files[i]);
1032                         if (stat(buf, &st) == -1)
1033                                 continue;
1034                         if (do_file(agent_fd, deleting, key_only, cert_only,
1035                             buf, qflag, skprovider,
1036                             dest_constraints, ndest_constraints) == -1)
1037                                 ret = 1;
1038                         else
1039                                 count++;
1040                 }
1041                 if (count == 0)
1042                         ret = 1;
1043         } else {
1044                 for (i = 0; i < argc; i++) {
1045                         if (do_file(agent_fd, deleting, key_only, cert_only,
1046                             argv[i], qflag, skprovider,
1047                             dest_constraints, ndest_constraints) == -1)
1048                                 ret = 1;
1049                 }
1050         }
1051 done:
1052         clear_pass();
1053         ssh_close_authentication_socket(agent_fd);
1054         return ret;
1055 }