1 /* $OpenBSD: sshconnect2.c,v 1.270 2018/03/24 19:28:43 markus Exp $ */ 2 /* 3 * Copyright (c) 2000 Markus Friedl. All rights reserved. 4 * Copyright (c) 2008 Damien Miller. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include "includes.h" 28 29 #include <sys/types.h> 30 #include <sys/socket.h> 31 #include <sys/wait.h> 32 #include <sys/stat.h> 33 34 #include <errno.h> 35 #include <fcntl.h> 36 #include <netdb.h> 37 #include <pwd.h> 38 #include <signal.h> 39 #include <stdarg.h> 40 #include <stdio.h> 41 #include <string.h> 42 #include <unistd.h> 43 #if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H) && !defined(BROKEN_STRNVIS) 44 #include <vis.h> 45 #endif 46 47 #include "openbsd-compat/sys-queue.h" 48 49 #include "xmalloc.h" 50 #include "ssh.h" 51 #include "ssh2.h" 52 #include "buffer.h" 53 #include "packet.h" 54 #include "compat.h" 55 #include "cipher.h" 56 #include "key.h" 57 #include "kex.h" 58 #include "myproposal.h" 59 #include "sshconnect.h" 60 #include "authfile.h" 61 #include "dh.h" 62 #include "authfd.h" 63 #include "log.h" 64 #include "misc.h" 65 #include "readconf.h" 66 #include "match.h" 67 #include "dispatch.h" 68 #include "canohost.h" 69 #include "msg.h" 70 #include "pathnames.h" 71 #include "uidswap.h" 72 #include "hostfile.h" 73 #include "ssherr.h" 74 #include "utf8.h" 75 76 #ifdef GSSAPI 77 #include "ssh-gss.h" 78 #endif 79 80 /* import */ 81 extern char *client_version_string; 82 extern char *server_version_string; 83 extern Options options; 84 85 /* 86 * SSH2 key exchange 87 */ 88 89 u_char *session_id2 = NULL; 90 u_int session_id2_len = 0; 91 92 char *xxx_host; 93 struct sockaddr *xxx_hostaddr; 94 95 static int 96 verify_host_key_callback(struct sshkey *hostkey, struct ssh *ssh) 97 { 98 if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1) 99 fatal("Host key verification failed."); 100 return 0; 101 } 102 103 static char * 104 order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port) 105 { 106 char *oavail, *avail, *first, *last, *alg, *hostname, *ret; 107 size_t maxlen; 108 struct hostkeys *hostkeys; 109 int ktype; 110 u_int i; 111 112 /* Find all hostkeys for this hostname */ 113 get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL); 114 hostkeys = init_hostkeys(); 115 for (i = 0; i < options.num_user_hostfiles; i++) 116 load_hostkeys(hostkeys, hostname, options.user_hostfiles[i]); 117 for (i = 0; i < options.num_system_hostfiles; i++) 118 load_hostkeys(hostkeys, hostname, options.system_hostfiles[i]); 119 120 oavail = avail = xstrdup(KEX_DEFAULT_PK_ALG); 121 maxlen = strlen(avail) + 1; 122 first = xmalloc(maxlen); 123 last = xmalloc(maxlen); 124 *first = *last = '\0'; 125 126 #define ALG_APPEND(to, from) \ 127 do { \ 128 if (*to != '\0') \ 129 strlcat(to, ",", maxlen); \ 130 strlcat(to, from, maxlen); \ 131 } while (0) 132 133 while ((alg = strsep(&avail, ",")) && *alg != '\0') { 134 if ((ktype = sshkey_type_from_name(alg)) == KEY_UNSPEC) 135 fatal("%s: unknown alg %s", __func__, alg); 136 if (lookup_key_in_hostkeys_by_type(hostkeys, 137 sshkey_type_plain(ktype), NULL)) 138 ALG_APPEND(first, alg); 139 else 140 ALG_APPEND(last, alg); 141 } 142 #undef ALG_APPEND 143 xasprintf(&ret, "%s%s%s", first, 144 (*first == '\0' || *last == '\0') ? "" : ",", last); 145 if (*first != '\0') 146 debug3("%s: prefer hostkeyalgs: %s", __func__, first); 147 148 free(first); 149 free(last); 150 free(hostname); 151 free(oavail); 152 free_hostkeys(hostkeys); 153 154 return ret; 155 } 156 157 void 158 ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port) 159 { 160 char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT }; 161 char *s; 162 struct kex *kex; 163 int r; 164 165 xxx_host = host; 166 xxx_hostaddr = hostaddr; 167 168 if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL) 169 fatal("%s: kex_names_cat", __func__); 170 myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(s); 171 myproposal[PROPOSAL_ENC_ALGS_CTOS] = 172 compat_cipher_proposal(options.ciphers); 173 myproposal[PROPOSAL_ENC_ALGS_STOC] = 174 compat_cipher_proposal(options.ciphers); 175 myproposal[PROPOSAL_COMP_ALGS_CTOS] = 176 myproposal[PROPOSAL_COMP_ALGS_STOC] = options.compression ? 177 "zlib@openssh.com,zlib,none" : "none,zlib@openssh.com,zlib"; 178 myproposal[PROPOSAL_MAC_ALGS_CTOS] = 179 myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; 180 if (options.hostkeyalgorithms != NULL) { 181 if (kex_assemble_names(KEX_DEFAULT_PK_ALG, 182 &options.hostkeyalgorithms) != 0) 183 fatal("%s: kex_assemble_namelist", __func__); 184 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = 185 compat_pkalg_proposal(options.hostkeyalgorithms); 186 } else { 187 /* Enforce default */ 188 options.hostkeyalgorithms = xstrdup(KEX_DEFAULT_PK_ALG); 189 /* Prefer algorithms that we already have keys for */ 190 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = 191 compat_pkalg_proposal( 192 order_hostkeyalgs(host, hostaddr, port)); 193 } 194 195 if (options.rekey_limit || options.rekey_interval) 196 packet_set_rekey_limits(options.rekey_limit, 197 options.rekey_interval); 198 199 /* start key exchange */ 200 if ((r = kex_setup(active_state, myproposal)) != 0) 201 fatal("kex_setup: %s", ssh_err(r)); 202 kex = active_state->kex; 203 #ifdef WITH_OPENSSL 204 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client; 205 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client; 206 kex->kex[KEX_DH_GRP14_SHA256] = kexdh_client; 207 kex->kex[KEX_DH_GRP16_SHA512] = kexdh_client; 208 kex->kex[KEX_DH_GRP18_SHA512] = kexdh_client; 209 kex->kex[KEX_DH_GEX_SHA1] = kexgex_client; 210 kex->kex[KEX_DH_GEX_SHA256] = kexgex_client; 211 # ifdef OPENSSL_HAS_ECC 212 kex->kex[KEX_ECDH_SHA2] = kexecdh_client; 213 # endif 214 #endif 215 kex->kex[KEX_C25519_SHA256] = kexc25519_client; 216 kex->client_version_string=client_version_string; 217 kex->server_version_string=server_version_string; 218 kex->verify_host_key=&verify_host_key_callback; 219 220 ssh_dispatch_run_fatal(active_state, DISPATCH_BLOCK, &kex->done); 221 222 /* remove ext-info from the KEX proposals for rekeying */ 223 myproposal[PROPOSAL_KEX_ALGS] = 224 compat_kex_proposal(options.kex_algorithms); 225 if ((r = kex_prop2buf(kex->my, myproposal)) != 0) 226 fatal("kex_prop2buf: %s", ssh_err(r)); 227 228 session_id2 = kex->session_id; 229 session_id2_len = kex->session_id_len; 230 231 #ifdef DEBUG_KEXDH 232 /* send 1st encrypted/maced/compressed message */ 233 packet_start(SSH2_MSG_IGNORE); 234 packet_put_cstring("markus"); 235 packet_send(); 236 packet_write_wait(); 237 #endif 238 } 239 240 /* 241 * Authenticate user 242 */ 243 244 typedef struct cauthctxt Authctxt; 245 typedef struct cauthmethod Authmethod; 246 typedef struct identity Identity; 247 typedef struct idlist Idlist; 248 249 struct identity { 250 TAILQ_ENTRY(identity) next; 251 int agent_fd; /* >=0 if agent supports key */ 252 struct sshkey *key; /* public/private key */ 253 char *filename; /* comment for agent-only keys */ 254 int tried; 255 int isprivate; /* key points to the private key */ 256 int userprovided; 257 }; 258 TAILQ_HEAD(idlist, identity); 259 260 struct cauthctxt { 261 const char *server_user; 262 const char *local_user; 263 const char *host; 264 const char *service; 265 struct cauthmethod *method; 266 sig_atomic_t success; 267 char *authlist; 268 int attempt; 269 /* pubkey */ 270 struct idlist keys; 271 int agent_fd; 272 /* hostbased */ 273 Sensitive *sensitive; 274 char *oktypes, *ktypes; 275 const char *active_ktype; 276 /* kbd-interactive */ 277 int info_req_seen; 278 /* generic */ 279 void *methoddata; 280 }; 281 282 struct cauthmethod { 283 char *name; /* string to compare against server's list */ 284 int (*userauth)(Authctxt *authctxt); 285 void (*cleanup)(Authctxt *authctxt); 286 int *enabled; /* flag in option struct that enables method */ 287 int *batch_flag; /* flag in option struct that disables method */ 288 }; 289 290 int input_userauth_service_accept(int, u_int32_t, struct ssh *); 291 int input_userauth_ext_info(int, u_int32_t, struct ssh *); 292 int input_userauth_success(int, u_int32_t, struct ssh *); 293 int input_userauth_success_unexpected(int, u_int32_t, struct ssh *); 294 int input_userauth_failure(int, u_int32_t, struct ssh *); 295 int input_userauth_banner(int, u_int32_t, struct ssh *); 296 int input_userauth_error(int, u_int32_t, struct ssh *); 297 int input_userauth_info_req(int, u_int32_t, struct ssh *); 298 int input_userauth_pk_ok(int, u_int32_t, struct ssh *); 299 int input_userauth_passwd_changereq(int, u_int32_t, struct ssh *); 300 301 int userauth_none(Authctxt *); 302 int userauth_pubkey(Authctxt *); 303 int userauth_passwd(Authctxt *); 304 int userauth_kbdint(Authctxt *); 305 int userauth_hostbased(Authctxt *); 306 307 #ifdef GSSAPI 308 int userauth_gssapi(Authctxt *authctxt); 309 int input_gssapi_response(int type, u_int32_t, struct ssh *); 310 int input_gssapi_token(int type, u_int32_t, struct ssh *); 311 int input_gssapi_hash(int type, u_int32_t, struct ssh *); 312 int input_gssapi_error(int, u_int32_t, struct ssh *); 313 int input_gssapi_errtok(int, u_int32_t, struct ssh *); 314 #endif 315 316 void userauth(Authctxt *, char *); 317 318 static int sign_and_send_pubkey(Authctxt *, Identity *); 319 static void pubkey_prepare(Authctxt *); 320 static void pubkey_cleanup(Authctxt *); 321 static void pubkey_reset(Authctxt *); 322 static struct sshkey *load_identity_file(Identity *); 323 324 static Authmethod *authmethod_get(char *authlist); 325 static Authmethod *authmethod_lookup(const char *name); 326 static char *authmethods_get(void); 327 328 Authmethod authmethods[] = { 329 #ifdef GSSAPI 330 {"gssapi-with-mic", 331 userauth_gssapi, 332 NULL, 333 &options.gss_authentication, 334 NULL}, 335 #endif 336 {"hostbased", 337 userauth_hostbased, 338 NULL, 339 &options.hostbased_authentication, 340 NULL}, 341 {"publickey", 342 userauth_pubkey, 343 NULL, 344 &options.pubkey_authentication, 345 NULL}, 346 {"keyboard-interactive", 347 userauth_kbdint, 348 NULL, 349 &options.kbd_interactive_authentication, 350 &options.batch_mode}, 351 {"password", 352 userauth_passwd, 353 NULL, 354 &options.password_authentication, 355 &options.batch_mode}, 356 {"none", 357 userauth_none, 358 NULL, 359 NULL, 360 NULL}, 361 {NULL, NULL, NULL, NULL, NULL} 362 }; 363 364 void 365 ssh_userauth2(const char *local_user, const char *server_user, char *host, 366 Sensitive *sensitive) 367 { 368 struct ssh *ssh = active_state; 369 Authctxt authctxt; 370 int r; 371 372 if (options.challenge_response_authentication) 373 options.kbd_interactive_authentication = 1; 374 if (options.preferred_authentications == NULL) 375 options.preferred_authentications = authmethods_get(); 376 377 /* setup authentication context */ 378 memset(&authctxt, 0, sizeof(authctxt)); 379 pubkey_prepare(&authctxt); 380 authctxt.server_user = server_user; 381 authctxt.local_user = local_user; 382 authctxt.host = host; 383 authctxt.service = "ssh-connection"; /* service name */ 384 authctxt.success = 0; 385 authctxt.method = authmethod_lookup("none"); 386 authctxt.authlist = NULL; 387 authctxt.methoddata = NULL; 388 authctxt.sensitive = sensitive; 389 authctxt.active_ktype = authctxt.oktypes = authctxt.ktypes = NULL; 390 authctxt.info_req_seen = 0; 391 authctxt.agent_fd = -1; 392 if (authctxt.method == NULL) 393 fatal("ssh_userauth2: internal error: cannot send userauth none request"); 394 395 if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_REQUEST)) != 0 || 396 (r = sshpkt_put_cstring(ssh, "ssh-userauth")) != 0 || 397 (r = sshpkt_send(ssh)) != 0) 398 fatal("%s: %s", __func__, ssh_err(r)); 399 400 ssh->authctxt = &authctxt; 401 ssh_dispatch_init(ssh, &input_userauth_error); 402 ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_ext_info); 403 ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_ACCEPT, &input_userauth_service_accept); 404 ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &authctxt.success); /* loop until success */ 405 ssh->authctxt = NULL; 406 407 pubkey_cleanup(&authctxt); 408 ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL); 409 410 if (!authctxt.success) 411 fatal("Authentication failed."); 412 debug("Authentication succeeded (%s).", authctxt.method->name); 413 } 414 415 /* ARGSUSED */ 416 int 417 input_userauth_service_accept(int type, u_int32_t seq, struct ssh *ssh) 418 { 419 Authctxt *authctxt = ssh->authctxt; 420 int r; 421 422 if (ssh_packet_remaining(ssh) > 0) { 423 char *reply; 424 425 if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0) 426 goto out; 427 debug2("service_accept: %s", reply); 428 free(reply); 429 } else { 430 debug2("buggy server: service_accept w/o service"); 431 } 432 if ((r = sshpkt_get_end(ssh)) != 0) 433 goto out; 434 debug("SSH2_MSG_SERVICE_ACCEPT received"); 435 436 /* initial userauth request */ 437 userauth_none(authctxt); 438 439 ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error); 440 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); 441 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); 442 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); 443 r = 0; 444 out: 445 return r; 446 } 447 448 /* ARGSUSED */ 449 int 450 input_userauth_ext_info(int type, u_int32_t seqnr, struct ssh *ssh) 451 { 452 return kex_input_ext_info(type, seqnr, ssh); 453 } 454 455 void 456 userauth(Authctxt *authctxt, char *authlist) 457 { 458 if (authctxt->method != NULL && authctxt->method->cleanup != NULL) 459 authctxt->method->cleanup(authctxt); 460 461 free(authctxt->methoddata); 462 authctxt->methoddata = NULL; 463 if (authlist == NULL) { 464 authlist = authctxt->authlist; 465 } else { 466 free(authctxt->authlist); 467 authctxt->authlist = authlist; 468 } 469 for (;;) { 470 Authmethod *method = authmethod_get(authlist); 471 if (method == NULL) 472 fatal("%s@%s: Permission denied (%s).", 473 authctxt->server_user, authctxt->host, authlist); 474 authctxt->method = method; 475 476 /* reset the per method handler */ 477 dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN, 478 SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL); 479 480 /* and try new method */ 481 if (method->userauth(authctxt) != 0) { 482 debug2("we sent a %s packet, wait for reply", method->name); 483 break; 484 } else { 485 debug2("we did not send a packet, disable method"); 486 method->enabled = NULL; 487 } 488 } 489 } 490 491 /* ARGSUSED */ 492 int 493 input_userauth_error(int type, u_int32_t seq, struct ssh *ssh) 494 { 495 fatal("input_userauth_error: bad message during authentication: " 496 "type %d", type); 497 return 0; 498 } 499 500 /* ARGSUSED */ 501 int 502 input_userauth_banner(int type, u_int32_t seq, struct ssh *ssh) 503 { 504 char *msg, *lang; 505 u_int len; 506 507 debug3("%s", __func__); 508 msg = packet_get_string(&len); 509 lang = packet_get_string(NULL); 510 if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO) 511 fmprintf(stderr, "%s", msg); 512 free(msg); 513 free(lang); 514 return 0; 515 } 516 517 /* ARGSUSED */ 518 int 519 input_userauth_success(int type, u_int32_t seq, struct ssh *ssh) 520 { 521 Authctxt *authctxt = ssh->authctxt; 522 523 if (authctxt == NULL) 524 fatal("input_userauth_success: no authentication context"); 525 free(authctxt->authlist); 526 authctxt->authlist = NULL; 527 if (authctxt->method != NULL && authctxt->method->cleanup != NULL) 528 authctxt->method->cleanup(authctxt); 529 free(authctxt->methoddata); 530 authctxt->methoddata = NULL; 531 authctxt->success = 1; /* break out */ 532 return 0; 533 } 534 535 int 536 input_userauth_success_unexpected(int type, u_int32_t seq, struct ssh *ssh) 537 { 538 Authctxt *authctxt = ssh->authctxt; 539 540 if (authctxt == NULL) 541 fatal("%s: no authentication context", __func__); 542 543 fatal("Unexpected authentication success during %s.", 544 authctxt->method->name); 545 return 0; 546 } 547 548 /* ARGSUSED */ 549 int 550 input_userauth_failure(int type, u_int32_t seq, struct ssh *ssh) 551 { 552 Authctxt *authctxt = ssh->authctxt; 553 char *authlist = NULL; 554 int partial; 555 556 if (authctxt == NULL) 557 fatal("input_userauth_failure: no authentication context"); 558 559 authlist = packet_get_string(NULL); 560 partial = packet_get_char(); 561 packet_check_eom(); 562 563 if (partial != 0) { 564 verbose("Authenticated with partial success."); 565 /* reset state */ 566 pubkey_reset(authctxt); 567 } 568 debug("Authentications that can continue: %s", authlist); 569 570 userauth(authctxt, authlist); 571 return 0; 572 } 573 574 /* ARGSUSED */ 575 int 576 input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh) 577 { 578 Authctxt *authctxt = ssh->authctxt; 579 struct sshkey *key = NULL; 580 Identity *id = NULL; 581 int pktype, sent = 0; 582 u_int alen, blen; 583 char *pkalg, *fp; 584 u_char *pkblob; 585 586 if (authctxt == NULL) 587 fatal("input_userauth_pk_ok: no authentication context"); 588 589 pkalg = packet_get_string(&alen); 590 pkblob = packet_get_string(&blen); 591 packet_check_eom(); 592 593 debug("Server accepts key: pkalg %s blen %u", pkalg, blen); 594 595 if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { 596 debug("unknown pkalg %s", pkalg); 597 goto done; 598 } 599 if ((key = key_from_blob(pkblob, blen)) == NULL) { 600 debug("no key from blob. pkalg %s", pkalg); 601 goto done; 602 } 603 if (key->type != pktype) { 604 error("input_userauth_pk_ok: type mismatch " 605 "for decoded key (received %d, expected %d)", 606 key->type, pktype); 607 goto done; 608 } 609 if ((fp = sshkey_fingerprint(key, options.fingerprint_hash, 610 SSH_FP_DEFAULT)) == NULL) 611 goto done; 612 debug2("input_userauth_pk_ok: fp %s", fp); 613 free(fp); 614 615 /* 616 * search keys in the reverse order, because last candidate has been 617 * moved to the end of the queue. this also avoids confusion by 618 * duplicate keys 619 */ 620 TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) { 621 if (key_equal(key, id->key)) { 622 sent = sign_and_send_pubkey(authctxt, id); 623 break; 624 } 625 } 626 done: 627 key_free(key); 628 free(pkalg); 629 free(pkblob); 630 631 /* try another method if we did not send a packet */ 632 if (sent == 0) 633 userauth(authctxt, NULL); 634 return 0; 635 } 636 637 #ifdef GSSAPI 638 int 639 userauth_gssapi(Authctxt *authctxt) 640 { 641 Gssctxt *gssctxt = NULL; 642 static gss_OID_set gss_supported = NULL; 643 static u_int mech = 0; 644 OM_uint32 min; 645 int ok = 0; 646 647 /* Try one GSSAPI method at a time, rather than sending them all at 648 * once. */ 649 650 if (gss_supported == NULL) 651 gss_indicate_mechs(&min, &gss_supported); 652 653 /* Check to see if the mechanism is usable before we offer it */ 654 while (mech < gss_supported->count && !ok) { 655 /* My DER encoding requires length<128 */ 656 if (gss_supported->elements[mech].length < 128 && 657 ssh_gssapi_check_mechanism(&gssctxt, 658 &gss_supported->elements[mech], authctxt->host)) { 659 ok = 1; /* Mechanism works */ 660 } else { 661 mech++; 662 } 663 } 664 665 if (!ok) 666 return 0; 667 668 authctxt->methoddata=(void *)gssctxt; 669 670 packet_start(SSH2_MSG_USERAUTH_REQUEST); 671 packet_put_cstring(authctxt->server_user); 672 packet_put_cstring(authctxt->service); 673 packet_put_cstring(authctxt->method->name); 674 675 packet_put_int(1); 676 677 packet_put_int((gss_supported->elements[mech].length) + 2); 678 packet_put_char(SSH_GSS_OIDTYPE); 679 packet_put_char(gss_supported->elements[mech].length); 680 packet_put_raw(gss_supported->elements[mech].elements, 681 gss_supported->elements[mech].length); 682 683 packet_send(); 684 685 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response); 686 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token); 687 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error); 688 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok); 689 690 mech++; /* Move along to next candidate */ 691 692 return 1; 693 } 694 695 static OM_uint32 696 process_gssapi_token(struct ssh *ssh, gss_buffer_t recv_tok) 697 { 698 Authctxt *authctxt = ssh->authctxt; 699 Gssctxt *gssctxt = authctxt->methoddata; 700 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; 701 gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; 702 gss_buffer_desc gssbuf; 703 OM_uint32 status, ms, flags; 704 Buffer b; 705 706 status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, 707 recv_tok, &send_tok, &flags); 708 709 if (send_tok.length > 0) { 710 if (GSS_ERROR(status)) 711 packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); 712 else 713 packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); 714 715 packet_put_string(send_tok.value, send_tok.length); 716 packet_send(); 717 gss_release_buffer(&ms, &send_tok); 718 } 719 720 if (status == GSS_S_COMPLETE) { 721 /* send either complete or MIC, depending on mechanism */ 722 if (!(flags & GSS_C_INTEG_FLAG)) { 723 packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE); 724 packet_send(); 725 } else { 726 ssh_gssapi_buildmic(&b, authctxt->server_user, 727 authctxt->service, "gssapi-with-mic"); 728 729 gssbuf.value = buffer_ptr(&b); 730 gssbuf.length = buffer_len(&b); 731 732 status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic); 733 734 if (!GSS_ERROR(status)) { 735 packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC); 736 packet_put_string(mic.value, mic.length); 737 738 packet_send(); 739 } 740 741 buffer_free(&b); 742 gss_release_buffer(&ms, &mic); 743 } 744 } 745 746 return status; 747 } 748 749 /* ARGSUSED */ 750 int 751 input_gssapi_response(int type, u_int32_t plen, struct ssh *ssh) 752 { 753 Authctxt *authctxt = ssh->authctxt; 754 Gssctxt *gssctxt; 755 int oidlen; 756 char *oidv; 757 758 if (authctxt == NULL) 759 fatal("input_gssapi_response: no authentication context"); 760 gssctxt = authctxt->methoddata; 761 762 /* Setup our OID */ 763 oidv = packet_get_string(&oidlen); 764 765 if (oidlen <= 2 || 766 oidv[0] != SSH_GSS_OIDTYPE || 767 oidv[1] != oidlen - 2) { 768 free(oidv); 769 debug("Badly encoded mechanism OID received"); 770 userauth(authctxt, NULL); 771 return 0; 772 } 773 774 if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2)) 775 fatal("Server returned different OID than expected"); 776 777 packet_check_eom(); 778 779 free(oidv); 780 781 if (GSS_ERROR(process_gssapi_token(ssh, GSS_C_NO_BUFFER))) { 782 /* Start again with next method on list */ 783 debug("Trying to start again"); 784 userauth(authctxt, NULL); 785 return 0; 786 } 787 return 0; 788 } 789 790 /* ARGSUSED */ 791 int 792 input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh) 793 { 794 Authctxt *authctxt = ssh->authctxt; 795 gss_buffer_desc recv_tok; 796 OM_uint32 status; 797 u_int slen; 798 799 if (authctxt == NULL) 800 fatal("input_gssapi_response: no authentication context"); 801 802 recv_tok.value = packet_get_string(&slen); 803 recv_tok.length = slen; /* safe typecast */ 804 805 packet_check_eom(); 806 807 status = process_gssapi_token(ssh, &recv_tok); 808 809 free(recv_tok.value); 810 811 if (GSS_ERROR(status)) { 812 /* Start again with the next method in the list */ 813 userauth(authctxt, NULL); 814 return 0; 815 } 816 return 0; 817 } 818 819 /* ARGSUSED */ 820 int 821 input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh) 822 { 823 Authctxt *authctxt = ssh->authctxt; 824 Gssctxt *gssctxt; 825 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; 826 gss_buffer_desc recv_tok; 827 OM_uint32 ms; 828 u_int len; 829 830 if (authctxt == NULL) 831 fatal("input_gssapi_response: no authentication context"); 832 gssctxt = authctxt->methoddata; 833 834 recv_tok.value = packet_get_string(&len); 835 recv_tok.length = len; 836 837 packet_check_eom(); 838 839 /* Stick it into GSSAPI and see what it says */ 840 (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, 841 &recv_tok, &send_tok, NULL); 842 843 free(recv_tok.value); 844 gss_release_buffer(&ms, &send_tok); 845 846 /* Server will be returning a failed packet after this one */ 847 return 0; 848 } 849 850 /* ARGSUSED */ 851 int 852 input_gssapi_error(int type, u_int32_t plen, struct ssh *ssh) 853 { 854 char *msg; 855 char *lang; 856 857 /* maj */(void)packet_get_int(); 858 /* min */(void)packet_get_int(); 859 msg=packet_get_string(NULL); 860 lang=packet_get_string(NULL); 861 862 packet_check_eom(); 863 864 debug("Server GSSAPI Error:\n%s", msg); 865 free(msg); 866 free(lang); 867 return 0; 868 } 869 #endif /* GSSAPI */ 870 871 int 872 userauth_none(Authctxt *authctxt) 873 { 874 /* initial userauth request */ 875 packet_start(SSH2_MSG_USERAUTH_REQUEST); 876 packet_put_cstring(authctxt->server_user); 877 packet_put_cstring(authctxt->service); 878 packet_put_cstring(authctxt->method->name); 879 packet_send(); 880 return 1; 881 } 882 883 int 884 userauth_passwd(Authctxt *authctxt) 885 { 886 static int attempt = 0; 887 char prompt[256]; 888 char *password; 889 const char *host = options.host_key_alias ? options.host_key_alias : 890 authctxt->host; 891 892 if (attempt++ >= options.number_of_password_prompts) 893 return 0; 894 895 if (attempt != 1) 896 error("Permission denied, please try again."); 897 898 snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", 899 authctxt->server_user, host); 900 password = read_passphrase(prompt, 0); 901 packet_start(SSH2_MSG_USERAUTH_REQUEST); 902 packet_put_cstring(authctxt->server_user); 903 packet_put_cstring(authctxt->service); 904 packet_put_cstring(authctxt->method->name); 905 packet_put_char(0); 906 packet_put_cstring(password); 907 explicit_bzero(password, strlen(password)); 908 free(password); 909 packet_add_padding(64); 910 packet_send(); 911 912 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, 913 &input_userauth_passwd_changereq); 914 915 return 1; 916 } 917 918 /* 919 * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST 920 */ 921 /* ARGSUSED */ 922 int 923 input_userauth_passwd_changereq(int type, u_int32_t seqnr, struct ssh *ssh) 924 { 925 Authctxt *authctxt = ssh->authctxt; 926 char *info, *lang, *password = NULL, *retype = NULL; 927 char prompt[256]; 928 const char *host; 929 930 debug2("input_userauth_passwd_changereq"); 931 932 if (authctxt == NULL) 933 fatal("input_userauth_passwd_changereq: " 934 "no authentication context"); 935 host = options.host_key_alias ? options.host_key_alias : authctxt->host; 936 937 info = packet_get_string(NULL); 938 lang = packet_get_string(NULL); 939 if (strlen(info) > 0) 940 logit("%s", info); 941 free(info); 942 free(lang); 943 packet_start(SSH2_MSG_USERAUTH_REQUEST); 944 packet_put_cstring(authctxt->server_user); 945 packet_put_cstring(authctxt->service); 946 packet_put_cstring(authctxt->method->name); 947 packet_put_char(1); /* additional info */ 948 snprintf(prompt, sizeof(prompt), 949 "Enter %.30s@%.128s's old password: ", 950 authctxt->server_user, host); 951 password = read_passphrase(prompt, 0); 952 packet_put_cstring(password); 953 explicit_bzero(password, strlen(password)); 954 free(password); 955 password = NULL; 956 while (password == NULL) { 957 snprintf(prompt, sizeof(prompt), 958 "Enter %.30s@%.128s's new password: ", 959 authctxt->server_user, host); 960 password = read_passphrase(prompt, RP_ALLOW_EOF); 961 if (password == NULL) { 962 /* bail out */ 963 return 0; 964 } 965 snprintf(prompt, sizeof(prompt), 966 "Retype %.30s@%.128s's new password: ", 967 authctxt->server_user, host); 968 retype = read_passphrase(prompt, 0); 969 if (strcmp(password, retype) != 0) { 970 explicit_bzero(password, strlen(password)); 971 free(password); 972 logit("Mismatch; try again, EOF to quit."); 973 password = NULL; 974 } 975 explicit_bzero(retype, strlen(retype)); 976 free(retype); 977 } 978 packet_put_cstring(password); 979 explicit_bzero(password, strlen(password)); 980 free(password); 981 packet_add_padding(64); 982 packet_send(); 983 984 dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, 985 &input_userauth_passwd_changereq); 986 return 0; 987 } 988 989 static const char * 990 key_sign_encode(const struct sshkey *key) 991 { 992 struct ssh *ssh = active_state; 993 994 if (key->type == KEY_RSA) { 995 switch (ssh->kex->rsa_sha2) { 996 case 256: 997 return "rsa-sha2-256"; 998 case 512: 999 return "rsa-sha2-512"; 1000 } 1001 } 1002 return key_ssh_name(key); 1003 } 1004 1005 /* 1006 * Some agents will return ssh-rsa signatures when asked to make a 1007 * rsa-sha2-* signature. Check what they actually gave back and warn the 1008 * user if the agent has returned an unexpected type. 1009 */ 1010 static int 1011 check_sigtype(const struct sshkey *key, const u_char *sig, size_t len) 1012 { 1013 int r; 1014 char *sigtype = NULL; 1015 const char *alg = key_sign_encode(key); 1016 1017 if (sshkey_is_cert(key)) 1018 return 0; 1019 if ((r = sshkey_sigtype(sig, len, &sigtype)) != 0) 1020 return r; 1021 if (strcmp(sigtype, alg) != 0) { 1022 logit("warning: agent returned different signature type %s " 1023 "(expected %s)", sigtype, alg); 1024 } 1025 free(sigtype); 1026 /* Incorrect signature types aren't an error ... yet */ 1027 return 0; 1028 } 1029 1030 static int 1031 identity_sign(struct identity *id, u_char **sigp, size_t *lenp, 1032 const u_char *data, size_t datalen, u_int compat) 1033 { 1034 struct sshkey *prv; 1035 int r; 1036 1037 /* the agent supports this key */ 1038 if (id->key != NULL && id->agent_fd != -1) { 1039 if ((r = ssh_agent_sign(id->agent_fd, id->key, sigp, lenp, 1040 data, datalen, key_sign_encode(id->key), compat)) != 0 || 1041 (r = check_sigtype(id->key, *sigp, *lenp)) != 0) 1042 return r; 1043 return 0; 1044 } 1045 1046 /* 1047 * we have already loaded the private key or 1048 * the private key is stored in external hardware 1049 */ 1050 if (id->key != NULL && 1051 (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))) 1052 return (sshkey_sign(id->key, sigp, lenp, data, datalen, 1053 key_sign_encode(id->key), compat)); 1054 1055 /* load the private key from the file */ 1056 if ((prv = load_identity_file(id)) == NULL) 1057 return SSH_ERR_KEY_NOT_FOUND; 1058 if (id->key != NULL && !sshkey_equal_public(prv, id->key)) { 1059 error("%s: private key %s contents do not match public", 1060 __func__, id->filename); 1061 return SSH_ERR_KEY_NOT_FOUND; 1062 } 1063 r = sshkey_sign(prv, sigp, lenp, data, datalen, 1064 key_sign_encode(prv), compat); 1065 sshkey_free(prv); 1066 return r; 1067 } 1068 1069 static int 1070 id_filename_matches(Identity *id, Identity *private_id) 1071 { 1072 const char *suffixes[] = { ".pub", "-cert.pub", NULL }; 1073 size_t len = strlen(id->filename), plen = strlen(private_id->filename); 1074 size_t i, slen; 1075 1076 if (strcmp(id->filename, private_id->filename) == 0) 1077 return 1; 1078 for (i = 0; suffixes[i]; i++) { 1079 slen = strlen(suffixes[i]); 1080 if (len > slen && plen == len - slen && 1081 strcmp(id->filename + (len - slen), suffixes[i]) == 0 && 1082 memcmp(id->filename, private_id->filename, plen) == 0) 1083 return 1; 1084 } 1085 return 0; 1086 } 1087 1088 static int 1089 sign_and_send_pubkey(Authctxt *authctxt, Identity *id) 1090 { 1091 Buffer b; 1092 Identity *private_id; 1093 u_char *blob, *signature; 1094 size_t slen; 1095 u_int bloblen, skip = 0; 1096 int matched, ret = -1, have_sig = 1; 1097 char *fp; 1098 1099 if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash, 1100 SSH_FP_DEFAULT)) == NULL) 1101 return 0; 1102 debug3("%s: %s %s", __func__, key_type(id->key), fp); 1103 free(fp); 1104 1105 if (key_to_blob(id->key, &blob, &bloblen) == 0) { 1106 /* we cannot handle this key */ 1107 debug3("sign_and_send_pubkey: cannot handle key"); 1108 return 0; 1109 } 1110 /* data to be signed */ 1111 buffer_init(&b); 1112 if (datafellows & SSH_OLD_SESSIONID) { 1113 buffer_append(&b, session_id2, session_id2_len); 1114 skip = session_id2_len; 1115 } else { 1116 buffer_put_string(&b, session_id2, session_id2_len); 1117 skip = buffer_len(&b); 1118 } 1119 buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); 1120 buffer_put_cstring(&b, authctxt->server_user); 1121 buffer_put_cstring(&b, authctxt->service); 1122 buffer_put_cstring(&b, authctxt->method->name); 1123 buffer_put_char(&b, have_sig); 1124 buffer_put_cstring(&b, key_sign_encode(id->key)); 1125 buffer_put_string(&b, blob, bloblen); 1126 1127 /* 1128 * If the key is an certificate, try to find a matching private key 1129 * and use it to complete the signature. 1130 * If no such private key exists, fall back to trying the certificate 1131 * key itself in case it has a private half already loaded. 1132 */ 1133 if (key_is_cert(id->key)) { 1134 matched = 0; 1135 TAILQ_FOREACH(private_id, &authctxt->keys, next) { 1136 if (sshkey_equal_public(id->key, private_id->key) && 1137 id->key->type != private_id->key->type) { 1138 id = private_id; 1139 matched = 1; 1140 break; 1141 } 1142 } 1143 /* 1144 * Exact key matches are preferred, but also allow 1145 * filename matches for non-PKCS#11/agent keys that 1146 * didn't load public keys. This supports the case 1147 * of keeping just a private key file and public 1148 * certificate on disk. 1149 */ 1150 if (!matched && !id->isprivate && id->agent_fd == -1 && 1151 (id->key->flags & SSHKEY_FLAG_EXT) == 0) { 1152 TAILQ_FOREACH(private_id, &authctxt->keys, next) { 1153 if (private_id->key == NULL && 1154 id_filename_matches(id, private_id)) { 1155 id = private_id; 1156 matched = 1; 1157 break; 1158 } 1159 } 1160 } 1161 if (matched) { 1162 debug2("%s: using private key \"%s\"%s for " 1163 "certificate", __func__, id->filename, 1164 id->agent_fd != -1 ? " from agent" : ""); 1165 } else { 1166 debug("%s: no separate private key for certificate " 1167 "\"%s\"", __func__, id->filename); 1168 } 1169 } 1170 1171 /* generate signature */ 1172 ret = identity_sign(id, &signature, &slen, 1173 buffer_ptr(&b), buffer_len(&b), datafellows); 1174 if (ret != 0) { 1175 if (ret != SSH_ERR_KEY_NOT_FOUND) 1176 error("%s: signing failed: %s", __func__, ssh_err(ret)); 1177 free(blob); 1178 buffer_free(&b); 1179 return 0; 1180 } 1181 #ifdef DEBUG_PK 1182 buffer_dump(&b); 1183 #endif 1184 free(blob); 1185 1186 /* append signature */ 1187 buffer_put_string(&b, signature, slen); 1188 free(signature); 1189 1190 /* skip session id and packet type */ 1191 if (buffer_len(&b) < skip + 1) 1192 fatal("userauth_pubkey: internal error"); 1193 buffer_consume(&b, skip + 1); 1194 1195 /* put remaining data from buffer into packet */ 1196 packet_start(SSH2_MSG_USERAUTH_REQUEST); 1197 packet_put_raw(buffer_ptr(&b), buffer_len(&b)); 1198 buffer_free(&b); 1199 packet_send(); 1200 1201 return 1; 1202 } 1203 1204 static int 1205 send_pubkey_test(Authctxt *authctxt, Identity *id) 1206 { 1207 u_char *blob; 1208 u_int bloblen, have_sig = 0; 1209 1210 debug3("send_pubkey_test"); 1211 1212 if (key_to_blob(id->key, &blob, &bloblen) == 0) { 1213 /* we cannot handle this key */ 1214 debug3("send_pubkey_test: cannot handle key"); 1215 return 0; 1216 } 1217 /* register callback for USERAUTH_PK_OK message */ 1218 dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); 1219 1220 packet_start(SSH2_MSG_USERAUTH_REQUEST); 1221 packet_put_cstring(authctxt->server_user); 1222 packet_put_cstring(authctxt->service); 1223 packet_put_cstring(authctxt->method->name); 1224 packet_put_char(have_sig); 1225 packet_put_cstring(key_sign_encode(id->key)); 1226 packet_put_string(blob, bloblen); 1227 free(blob); 1228 packet_send(); 1229 return 1; 1230 } 1231 1232 static struct sshkey * 1233 load_identity_file(Identity *id) 1234 { 1235 struct sshkey *private = NULL; 1236 char prompt[300], *passphrase, *comment; 1237 int r, perm_ok = 0, quit = 0, i; 1238 struct stat st; 1239 1240 if (stat(id->filename, &st) < 0) { 1241 (id->userprovided ? logit : debug3)("no such identity: %s: %s", 1242 id->filename, strerror(errno)); 1243 return NULL; 1244 } 1245 snprintf(prompt, sizeof prompt, 1246 "Enter passphrase for key '%.100s': ", id->filename); 1247 for (i = 0; i <= options.number_of_password_prompts; i++) { 1248 if (i == 0) 1249 passphrase = ""; 1250 else { 1251 passphrase = read_passphrase(prompt, 0); 1252 if (*passphrase == '\0') { 1253 debug2("no passphrase given, try next key"); 1254 free(passphrase); 1255 break; 1256 } 1257 } 1258 switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename, 1259 passphrase, &private, &comment, &perm_ok))) { 1260 case 0: 1261 break; 1262 case SSH_ERR_KEY_WRONG_PASSPHRASE: 1263 if (options.batch_mode) { 1264 quit = 1; 1265 break; 1266 } 1267 if (i != 0) 1268 debug2("bad passphrase given, try again..."); 1269 break; 1270 case SSH_ERR_SYSTEM_ERROR: 1271 if (errno == ENOENT) { 1272 debug2("Load key \"%s\": %s", 1273 id->filename, ssh_err(r)); 1274 quit = 1; 1275 break; 1276 } 1277 /* FALLTHROUGH */ 1278 default: 1279 error("Load key \"%s\": %s", id->filename, ssh_err(r)); 1280 quit = 1; 1281 break; 1282 } 1283 if (!quit && private != NULL && id->agent_fd == -1 && 1284 !(id->key && id->isprivate)) 1285 maybe_add_key_to_agent(id->filename, private, comment, 1286 passphrase); 1287 if (i > 0) { 1288 explicit_bzero(passphrase, strlen(passphrase)); 1289 free(passphrase); 1290 } 1291 free(comment); 1292 if (private != NULL || quit) 1293 break; 1294 } 1295 return private; 1296 } 1297 1298 /* 1299 * try keys in the following order: 1300 * 1. certificates listed in the config file 1301 * 2. other input certificates 1302 * 3. agent keys that are found in the config file 1303 * 4. other agent keys 1304 * 5. keys that are only listed in the config file 1305 */ 1306 static void 1307 pubkey_prepare(Authctxt *authctxt) 1308 { 1309 struct identity *id, *id2, *tmp; 1310 struct idlist agent, files, *preferred; 1311 struct sshkey *key; 1312 int agent_fd = -1, i, r, found; 1313 size_t j; 1314 struct ssh_identitylist *idlist; 1315 1316 TAILQ_INIT(&agent); /* keys from the agent */ 1317 TAILQ_INIT(&files); /* keys from the config file */ 1318 preferred = &authctxt->keys; 1319 TAILQ_INIT(preferred); /* preferred order of keys */ 1320 1321 /* list of keys stored in the filesystem and PKCS#11 */ 1322 for (i = 0; i < options.num_identity_files; i++) { 1323 key = options.identity_keys[i]; 1324 if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER) 1325 continue; 1326 options.identity_keys[i] = NULL; 1327 id = xcalloc(1, sizeof(*id)); 1328 id->agent_fd = -1; 1329 id->key = key; 1330 id->filename = xstrdup(options.identity_files[i]); 1331 id->userprovided = options.identity_file_userprovided[i]; 1332 TAILQ_INSERT_TAIL(&files, id, next); 1333 } 1334 /* list of certificates specified by user */ 1335 for (i = 0; i < options.num_certificate_files; i++) { 1336 key = options.certificates[i]; 1337 if (!key_is_cert(key) || key->cert == NULL || 1338 key->cert->type != SSH2_CERT_TYPE_USER) 1339 continue; 1340 id = xcalloc(1, sizeof(*id)); 1341 id->agent_fd = -1; 1342 id->key = key; 1343 id->filename = xstrdup(options.certificate_files[i]); 1344 id->userprovided = options.certificate_file_userprovided[i]; 1345 TAILQ_INSERT_TAIL(preferred, id, next); 1346 } 1347 /* list of keys supported by the agent */ 1348 if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) { 1349 if (r != SSH_ERR_AGENT_NOT_PRESENT) 1350 debug("%s: ssh_get_authentication_socket: %s", 1351 __func__, ssh_err(r)); 1352 } else if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) { 1353 if (r != SSH_ERR_AGENT_NO_IDENTITIES) 1354 debug("%s: ssh_fetch_identitylist: %s", 1355 __func__, ssh_err(r)); 1356 close(agent_fd); 1357 } else { 1358 for (j = 0; j < idlist->nkeys; j++) { 1359 found = 0; 1360 TAILQ_FOREACH(id, &files, next) { 1361 /* 1362 * agent keys from the config file are 1363 * preferred 1364 */ 1365 if (sshkey_equal(idlist->keys[j], id->key)) { 1366 TAILQ_REMOVE(&files, id, next); 1367 TAILQ_INSERT_TAIL(preferred, id, next); 1368 id->agent_fd = agent_fd; 1369 found = 1; 1370 break; 1371 } 1372 } 1373 if (!found && !options.identities_only) { 1374 id = xcalloc(1, sizeof(*id)); 1375 /* XXX "steals" key/comment from idlist */ 1376 id->key = idlist->keys[j]; 1377 id->filename = idlist->comments[j]; 1378 idlist->keys[j] = NULL; 1379 idlist->comments[j] = NULL; 1380 id->agent_fd = agent_fd; 1381 TAILQ_INSERT_TAIL(&agent, id, next); 1382 } 1383 } 1384 ssh_free_identitylist(idlist); 1385 /* append remaining agent keys */ 1386 for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) { 1387 TAILQ_REMOVE(&agent, id, next); 1388 TAILQ_INSERT_TAIL(preferred, id, next); 1389 } 1390 authctxt->agent_fd = agent_fd; 1391 } 1392 /* Prefer PKCS11 keys that are explicitly listed */ 1393 TAILQ_FOREACH_SAFE(id, &files, next, tmp) { 1394 if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0) 1395 continue; 1396 found = 0; 1397 TAILQ_FOREACH(id2, &files, next) { 1398 if (id2->key == NULL || 1399 (id2->key->flags & SSHKEY_FLAG_EXT) == 0) 1400 continue; 1401 if (sshkey_equal(id->key, id2->key)) { 1402 TAILQ_REMOVE(&files, id, next); 1403 TAILQ_INSERT_TAIL(preferred, id, next); 1404 found = 1; 1405 break; 1406 } 1407 } 1408 /* If IdentitiesOnly set and key not found then don't use it */ 1409 if (!found && options.identities_only) { 1410 TAILQ_REMOVE(&files, id, next); 1411 explicit_bzero(id, sizeof(*id)); 1412 free(id); 1413 } 1414 } 1415 /* append remaining keys from the config file */ 1416 for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) { 1417 TAILQ_REMOVE(&files, id, next); 1418 TAILQ_INSERT_TAIL(preferred, id, next); 1419 } 1420 /* finally, filter by PubkeyAcceptedKeyTypes */ 1421 TAILQ_FOREACH_SAFE(id, preferred, next, id2) { 1422 if (id->key != NULL && 1423 match_pattern_list(sshkey_ssh_name(id->key), 1424 options.pubkey_key_types, 0) != 1) { 1425 debug("Skipping %s key %s - " 1426 "not in PubkeyAcceptedKeyTypes", 1427 sshkey_ssh_name(id->key), id->filename); 1428 TAILQ_REMOVE(preferred, id, next); 1429 sshkey_free(id->key); 1430 free(id->filename); 1431 memset(id, 0, sizeof(*id)); 1432 continue; 1433 } 1434 debug2("key: %s (%p)%s%s", id->filename, id->key, 1435 id->userprovided ? ", explicit" : "", 1436 id->agent_fd != -1 ? ", agent" : ""); 1437 } 1438 } 1439 1440 static void 1441 pubkey_cleanup(Authctxt *authctxt) 1442 { 1443 Identity *id; 1444 1445 if (authctxt->agent_fd != -1) 1446 ssh_close_authentication_socket(authctxt->agent_fd); 1447 for (id = TAILQ_FIRST(&authctxt->keys); id; 1448 id = TAILQ_FIRST(&authctxt->keys)) { 1449 TAILQ_REMOVE(&authctxt->keys, id, next); 1450 sshkey_free(id->key); 1451 free(id->filename); 1452 free(id); 1453 } 1454 } 1455 1456 static void 1457 pubkey_reset(Authctxt *authctxt) 1458 { 1459 Identity *id; 1460 1461 TAILQ_FOREACH(id, &authctxt->keys, next) 1462 id->tried = 0; 1463 } 1464 1465 static int 1466 try_identity(Identity *id) 1467 { 1468 if (!id->key) 1469 return (0); 1470 if (key_type_plain(id->key->type) == KEY_RSA && 1471 (datafellows & SSH_BUG_RSASIGMD5) != 0) { 1472 debug("Skipped %s key %s for RSA/MD5 server", 1473 key_type(id->key), id->filename); 1474 return (0); 1475 } 1476 return 1; 1477 } 1478 1479 int 1480 userauth_pubkey(Authctxt *authctxt) 1481 { 1482 Identity *id; 1483 int sent = 0; 1484 char *fp; 1485 1486 while ((id = TAILQ_FIRST(&authctxt->keys))) { 1487 if (id->tried++) 1488 return (0); 1489 /* move key to the end of the queue */ 1490 TAILQ_REMOVE(&authctxt->keys, id, next); 1491 TAILQ_INSERT_TAIL(&authctxt->keys, id, next); 1492 /* 1493 * send a test message if we have the public key. for 1494 * encrypted keys we cannot do this and have to load the 1495 * private key instead 1496 */ 1497 if (id->key != NULL) { 1498 if (try_identity(id)) { 1499 if ((fp = sshkey_fingerprint(id->key, 1500 options.fingerprint_hash, 1501 SSH_FP_DEFAULT)) == NULL) { 1502 error("%s: sshkey_fingerprint failed", 1503 __func__); 1504 return 0; 1505 } 1506 debug("Offering public key: %s %s %s", 1507 sshkey_type(id->key), fp, id->filename); 1508 free(fp); 1509 sent = send_pubkey_test(authctxt, id); 1510 } 1511 } else { 1512 debug("Trying private key: %s", id->filename); 1513 id->key = load_identity_file(id); 1514 if (id->key != NULL) { 1515 if (try_identity(id)) { 1516 id->isprivate = 1; 1517 sent = sign_and_send_pubkey( 1518 authctxt, id); 1519 } 1520 key_free(id->key); 1521 id->key = NULL; 1522 id->isprivate = 0; 1523 } 1524 } 1525 if (sent) 1526 return (sent); 1527 } 1528 return (0); 1529 } 1530 1531 /* 1532 * Send userauth request message specifying keyboard-interactive method. 1533 */ 1534 int 1535 userauth_kbdint(Authctxt *authctxt) 1536 { 1537 static int attempt = 0; 1538 1539 if (attempt++ >= options.number_of_password_prompts) 1540 return 0; 1541 /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */ 1542 if (attempt > 1 && !authctxt->info_req_seen) { 1543 debug3("userauth_kbdint: disable: no info_req_seen"); 1544 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL); 1545 return 0; 1546 } 1547 1548 debug2("userauth_kbdint"); 1549 packet_start(SSH2_MSG_USERAUTH_REQUEST); 1550 packet_put_cstring(authctxt->server_user); 1551 packet_put_cstring(authctxt->service); 1552 packet_put_cstring(authctxt->method->name); 1553 packet_put_cstring(""); /* lang */ 1554 packet_put_cstring(options.kbd_interactive_devices ? 1555 options.kbd_interactive_devices : ""); 1556 packet_send(); 1557 1558 dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); 1559 return 1; 1560 } 1561 1562 /* 1563 * parse INFO_REQUEST, prompt user and send INFO_RESPONSE 1564 */ 1565 int 1566 input_userauth_info_req(int type, u_int32_t seq, struct ssh *ssh) 1567 { 1568 Authctxt *authctxt = ssh->authctxt; 1569 char *name, *inst, *lang, *prompt, *response; 1570 u_int num_prompts, i; 1571 int echo = 0; 1572 1573 debug2("input_userauth_info_req"); 1574 1575 if (authctxt == NULL) 1576 fatal("input_userauth_info_req: no authentication context"); 1577 1578 authctxt->info_req_seen = 1; 1579 1580 name = packet_get_string(NULL); 1581 inst = packet_get_string(NULL); 1582 lang = packet_get_string(NULL); 1583 if (strlen(name) > 0) 1584 logit("%s", name); 1585 if (strlen(inst) > 0) 1586 logit("%s", inst); 1587 free(name); 1588 free(inst); 1589 free(lang); 1590 1591 num_prompts = packet_get_int(); 1592 /* 1593 * Begin to build info response packet based on prompts requested. 1594 * We commit to providing the correct number of responses, so if 1595 * further on we run into a problem that prevents this, we have to 1596 * be sure and clean this up and send a correct error response. 1597 */ 1598 packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE); 1599 packet_put_int(num_prompts); 1600 1601 debug2("input_userauth_info_req: num_prompts %d", num_prompts); 1602 for (i = 0; i < num_prompts; i++) { 1603 prompt = packet_get_string(NULL); 1604 echo = packet_get_char(); 1605 1606 response = read_passphrase(prompt, echo ? RP_ECHO : 0); 1607 1608 packet_put_cstring(response); 1609 explicit_bzero(response, strlen(response)); 1610 free(response); 1611 free(prompt); 1612 } 1613 packet_check_eom(); /* done with parsing incoming message. */ 1614 1615 packet_add_padding(64); 1616 packet_send(); 1617 return 0; 1618 } 1619 1620 static int 1621 ssh_keysign(struct sshkey *key, u_char **sigp, size_t *lenp, 1622 const u_char *data, size_t datalen) 1623 { 1624 struct sshbuf *b; 1625 struct stat st; 1626 pid_t pid; 1627 int i, r, to[2], from[2], status, sock = packet_get_connection_in(); 1628 u_char rversion = 0, version = 2; 1629 void (*osigchld)(int); 1630 1631 *sigp = NULL; 1632 *lenp = 0; 1633 1634 if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) { 1635 error("%s: not installed: %s", __func__, strerror(errno)); 1636 return -1; 1637 } 1638 if (fflush(stdout) != 0) { 1639 error("%s: fflush: %s", __func__, strerror(errno)); 1640 return -1; 1641 } 1642 if (pipe(to) < 0) { 1643 error("%s: pipe: %s", __func__, strerror(errno)); 1644 return -1; 1645 } 1646 if (pipe(from) < 0) { 1647 error("%s: pipe: %s", __func__, strerror(errno)); 1648 return -1; 1649 } 1650 if ((pid = fork()) < 0) { 1651 error("%s: fork: %s", __func__, strerror(errno)); 1652 return -1; 1653 } 1654 osigchld = signal(SIGCHLD, SIG_DFL); 1655 if (pid == 0) { 1656 /* keep the socket on exec */ 1657 fcntl(sock, F_SETFD, 0); 1658 permanently_drop_suid(getuid()); 1659 close(from[0]); 1660 if (dup2(from[1], STDOUT_FILENO) < 0) 1661 fatal("%s: dup2: %s", __func__, strerror(errno)); 1662 close(to[1]); 1663 if (dup2(to[0], STDIN_FILENO) < 0) 1664 fatal("%s: dup2: %s", __func__, strerror(errno)); 1665 close(from[1]); 1666 close(to[0]); 1667 /* Close everything but stdio and the socket */ 1668 for (i = STDERR_FILENO + 1; i < sock; i++) 1669 close(i); 1670 closefrom(sock + 1); 1671 debug3("%s: [child] pid=%ld, exec %s", 1672 __func__, (long)getpid(), _PATH_SSH_KEY_SIGN); 1673 execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL); 1674 fatal("%s: exec(%s): %s", __func__, _PATH_SSH_KEY_SIGN, 1675 strerror(errno)); 1676 } 1677 close(from[1]); 1678 close(to[0]); 1679 1680 if ((b = sshbuf_new()) == NULL) 1681 fatal("%s: sshbuf_new failed", __func__); 1682 /* send # of sock, data to be signed */ 1683 if ((r = sshbuf_put_u32(b, sock)) != 0 || 1684 (r = sshbuf_put_string(b, data, datalen)) != 0) 1685 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1686 if (ssh_msg_send(to[1], version, b) == -1) 1687 fatal("%s: couldn't send request", __func__); 1688 sshbuf_reset(b); 1689 r = ssh_msg_recv(from[0], b); 1690 close(from[0]); 1691 close(to[1]); 1692 if (r < 0) { 1693 error("%s: no reply", __func__); 1694 goto fail; 1695 } 1696 1697 errno = 0; 1698 while (waitpid(pid, &status, 0) < 0) { 1699 if (errno != EINTR) { 1700 error("%s: waitpid %ld: %s", 1701 __func__, (long)pid, strerror(errno)); 1702 goto fail; 1703 } 1704 } 1705 if (!WIFEXITED(status)) { 1706 error("%s: exited abnormally", __func__); 1707 goto fail; 1708 } 1709 if (WEXITSTATUS(status) != 0) { 1710 error("%s: exited with status %d", 1711 __func__, WEXITSTATUS(status)); 1712 goto fail; 1713 } 1714 if ((r = sshbuf_get_u8(b, &rversion)) != 0) { 1715 error("%s: buffer error: %s", __func__, ssh_err(r)); 1716 goto fail; 1717 } 1718 if (rversion != version) { 1719 error("%s: bad version", __func__); 1720 goto fail; 1721 } 1722 if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) { 1723 error("%s: buffer error: %s", __func__, ssh_err(r)); 1724 fail: 1725 signal(SIGCHLD, osigchld); 1726 sshbuf_free(b); 1727 return -1; 1728 } 1729 signal(SIGCHLD, osigchld); 1730 sshbuf_free(b); 1731 1732 return 0; 1733 } 1734 1735 int 1736 userauth_hostbased(Authctxt *authctxt) 1737 { 1738 struct ssh *ssh = active_state; 1739 struct sshkey *private = NULL; 1740 struct sshbuf *b = NULL; 1741 u_char *sig = NULL, *keyblob = NULL; 1742 char *fp = NULL, *chost = NULL, *lname = NULL; 1743 size_t siglen = 0, keylen = 0; 1744 int i, r, success = 0; 1745 1746 if (authctxt->ktypes == NULL) { 1747 authctxt->oktypes = xstrdup(options.hostbased_key_types); 1748 authctxt->ktypes = authctxt->oktypes; 1749 } 1750 1751 /* 1752 * Work through each listed type pattern in HostbasedKeyTypes, 1753 * trying each hostkey that matches the type in turn. 1754 */ 1755 for (;;) { 1756 if (authctxt->active_ktype == NULL) 1757 authctxt->active_ktype = strsep(&authctxt->ktypes, ","); 1758 if (authctxt->active_ktype == NULL || 1759 *authctxt->active_ktype == '\0') 1760 break; 1761 debug3("%s: trying key type %s", __func__, 1762 authctxt->active_ktype); 1763 1764 /* check for a useful key */ 1765 private = NULL; 1766 for (i = 0; i < authctxt->sensitive->nkeys; i++) { 1767 if (authctxt->sensitive->keys[i] == NULL || 1768 authctxt->sensitive->keys[i]->type == KEY_UNSPEC) 1769 continue; 1770 if (match_pattern_list( 1771 sshkey_ssh_name(authctxt->sensitive->keys[i]), 1772 authctxt->active_ktype, 0) != 1) 1773 continue; 1774 /* we take and free the key */ 1775 private = authctxt->sensitive->keys[i]; 1776 authctxt->sensitive->keys[i] = NULL; 1777 break; 1778 } 1779 /* Found one */ 1780 if (private != NULL) 1781 break; 1782 /* No more keys of this type; advance */ 1783 authctxt->active_ktype = NULL; 1784 } 1785 if (private == NULL) { 1786 free(authctxt->oktypes); 1787 authctxt->oktypes = authctxt->ktypes = NULL; 1788 authctxt->active_ktype = NULL; 1789 debug("No more client hostkeys for hostbased authentication."); 1790 goto out; 1791 } 1792 1793 if ((fp = sshkey_fingerprint(private, options.fingerprint_hash, 1794 SSH_FP_DEFAULT)) == NULL) { 1795 error("%s: sshkey_fingerprint failed", __func__); 1796 goto out; 1797 } 1798 debug("%s: trying hostkey %s %s", 1799 __func__, sshkey_ssh_name(private), fp); 1800 1801 /* figure out a name for the client host */ 1802 if ((lname = get_local_name(packet_get_connection_in())) == NULL) { 1803 error("%s: cannot get local ipaddr/name", __func__); 1804 goto out; 1805 } 1806 1807 /* XXX sshbuf_put_stringf? */ 1808 xasprintf(&chost, "%s.", lname); 1809 debug2("%s: chost %s", __func__, chost); 1810 1811 /* construct data */ 1812 if ((b = sshbuf_new()) == NULL) { 1813 error("%s: sshbuf_new failed", __func__); 1814 goto out; 1815 } 1816 if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) { 1817 error("%s: sshkey_to_blob: %s", __func__, ssh_err(r)); 1818 goto out; 1819 } 1820 if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 || 1821 (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 || 1822 (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 || 1823 (r = sshbuf_put_cstring(b, authctxt->service)) != 0 || 1824 (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 || 1825 (r = sshbuf_put_cstring(b, key_ssh_name(private))) != 0 || 1826 (r = sshbuf_put_string(b, keyblob, keylen)) != 0 || 1827 (r = sshbuf_put_cstring(b, chost)) != 0 || 1828 (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) { 1829 error("%s: buffer error: %s", __func__, ssh_err(r)); 1830 goto out; 1831 } 1832 1833 #ifdef DEBUG_PK 1834 sshbuf_dump(b, stderr); 1835 #endif 1836 if (authctxt->sensitive->external_keysign) 1837 r = ssh_keysign(private, &sig, &siglen, 1838 sshbuf_ptr(b), sshbuf_len(b)); 1839 else if ((r = sshkey_sign(private, &sig, &siglen, 1840 sshbuf_ptr(b), sshbuf_len(b), NULL, datafellows)) != 0) 1841 debug("%s: sshkey_sign: %s", __func__, ssh_err(r)); 1842 if (r != 0) { 1843 error("sign using hostkey %s %s failed", 1844 sshkey_ssh_name(private), fp); 1845 goto out; 1846 } 1847 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 || 1848 (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 || 1849 (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 || 1850 (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 || 1851 (r = sshpkt_put_cstring(ssh, key_ssh_name(private))) != 0 || 1852 (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 || 1853 (r = sshpkt_put_cstring(ssh, chost)) != 0 || 1854 (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 || 1855 (r = sshpkt_put_string(ssh, sig, siglen)) != 0 || 1856 (r = sshpkt_send(ssh)) != 0) { 1857 error("%s: packet error: %s", __func__, ssh_err(r)); 1858 goto out; 1859 } 1860 success = 1; 1861 1862 out: 1863 if (sig != NULL) { 1864 explicit_bzero(sig, siglen); 1865 free(sig); 1866 } 1867 free(keyblob); 1868 free(lname); 1869 free(fp); 1870 free(chost); 1871 sshkey_free(private); 1872 sshbuf_free(b); 1873 1874 return success; 1875 } 1876 1877 /* find auth method */ 1878 1879 /* 1880 * given auth method name, if configurable options permit this method fill 1881 * in auth_ident field and return true, otherwise return false. 1882 */ 1883 static int 1884 authmethod_is_enabled(Authmethod *method) 1885 { 1886 if (method == NULL) 1887 return 0; 1888 /* return false if options indicate this method is disabled */ 1889 if (method->enabled == NULL || *method->enabled == 0) 1890 return 0; 1891 /* return false if batch mode is enabled but method needs interactive mode */ 1892 if (method->batch_flag != NULL && *method->batch_flag != 0) 1893 return 0; 1894 return 1; 1895 } 1896 1897 static Authmethod * 1898 authmethod_lookup(const char *name) 1899 { 1900 Authmethod *method = NULL; 1901 if (name != NULL) 1902 for (method = authmethods; method->name != NULL; method++) 1903 if (strcmp(name, method->name) == 0) 1904 return method; 1905 debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); 1906 return NULL; 1907 } 1908 1909 /* XXX internal state */ 1910 static Authmethod *current = NULL; 1911 static char *supported = NULL; 1912 static char *preferred = NULL; 1913 1914 /* 1915 * Given the authentication method list sent by the server, return the 1916 * next method we should try. If the server initially sends a nil list, 1917 * use a built-in default list. 1918 */ 1919 static Authmethod * 1920 authmethod_get(char *authlist) 1921 { 1922 char *name = NULL; 1923 u_int next; 1924 1925 /* Use a suitable default if we're passed a nil list. */ 1926 if (authlist == NULL || strlen(authlist) == 0) 1927 authlist = options.preferred_authentications; 1928 1929 if (supported == NULL || strcmp(authlist, supported) != 0) { 1930 debug3("start over, passed a different list %s", authlist); 1931 free(supported); 1932 supported = xstrdup(authlist); 1933 preferred = options.preferred_authentications; 1934 debug3("preferred %s", preferred); 1935 current = NULL; 1936 } else if (current != NULL && authmethod_is_enabled(current)) 1937 return current; 1938 1939 for (;;) { 1940 if ((name = match_list(preferred, supported, &next)) == NULL) { 1941 debug("No more authentication methods to try."); 1942 current = NULL; 1943 return NULL; 1944 } 1945 preferred += next; 1946 debug3("authmethod_lookup %s", name); 1947 debug3("remaining preferred: %s", preferred); 1948 if ((current = authmethod_lookup(name)) != NULL && 1949 authmethod_is_enabled(current)) { 1950 debug3("authmethod_is_enabled %s", name); 1951 debug("Next authentication method: %s", name); 1952 free(name); 1953 return current; 1954 } 1955 free(name); 1956 } 1957 } 1958 1959 static char * 1960 authmethods_get(void) 1961 { 1962 Authmethod *method = NULL; 1963 Buffer b; 1964 char *list; 1965 1966 buffer_init(&b); 1967 for (method = authmethods; method->name != NULL; method++) { 1968 if (authmethod_is_enabled(method)) { 1969 if (buffer_len(&b) > 0) 1970 buffer_append(&b, ",", 1); 1971 buffer_append(&b, method->name, strlen(method->name)); 1972 } 1973 } 1974 if ((list = sshbuf_dup_string(&b)) == NULL) 1975 fatal("%s: sshbuf_dup_string failed", __func__); 1976 buffer_free(&b); 1977 return list; 1978 } 1979 1980