1 /* $OpenBSD: monitor_wrap.c,v 1.107 2018/07/20 03:46:34 djm Exp $ */ 2 /* 3 * Copyright 2002 Niels Provos <provos@citi.umich.edu> 4 * Copyright 2002 Markus Friedl <markus@openbsd.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include "includes.h" 29 30 #include <sys/types.h> 31 #include <sys/uio.h> 32 33 #include <errno.h> 34 #include <pwd.h> 35 #include <signal.h> 36 #include <stdarg.h> 37 #include <stdio.h> 38 #include <string.h> 39 #include <unistd.h> 40 41 #ifdef WITH_OPENSSL 42 #include <openssl/bn.h> 43 #include <openssl/dh.h> 44 #include <openssl/evp.h> 45 #endif 46 47 #include "openbsd-compat/sys-queue.h" 48 #include "xmalloc.h" 49 #include "ssh.h" 50 #ifdef WITH_OPENSSL 51 #include "dh.h" 52 #endif 53 #include "sshbuf.h" 54 #include "sshkey.h" 55 #include "cipher.h" 56 #include "kex.h" 57 #include "hostfile.h" 58 #include "auth.h" 59 #include "auth-options.h" 60 #include "packet.h" 61 #include "mac.h" 62 #include "log.h" 63 #include "auth-pam.h" 64 #include "monitor.h" 65 #ifdef GSSAPI 66 #include "ssh-gss.h" 67 #endif 68 #include "monitor_wrap.h" 69 #include "atomicio.h" 70 #include "monitor_fdpass.h" 71 #include "misc.h" 72 73 #include "channels.h" 74 #include "session.h" 75 #include "servconf.h" 76 77 #include "ssherr.h" 78 79 /* Imports */ 80 extern struct monitor *pmonitor; 81 extern struct sshbuf *loginmsg; 82 extern ServerOptions options; 83 84 void 85 mm_log_handler(LogLevel level, const char *msg, void *ctx) 86 { 87 struct sshbuf *log_msg; 88 struct monitor *mon = (struct monitor *)ctx; 89 int r; 90 size_t len; 91 92 if (mon->m_log_sendfd == -1) 93 fatal("%s: no log channel", __func__); 94 95 if ((log_msg = sshbuf_new()) == NULL) 96 fatal("%s: sshbuf_new failed", __func__); 97 98 if ((r = sshbuf_put_u32(log_msg, 0)) != 0 || /* length; filled below */ 99 (r = sshbuf_put_u32(log_msg, level)) != 0 || 100 (r = sshbuf_put_cstring(log_msg, msg)) != 0) 101 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 102 if ((len = sshbuf_len(log_msg)) < 4 || len > 0xffffffff) 103 fatal("%s: bad length %zu", __func__, len); 104 POKE_U32(sshbuf_mutable_ptr(log_msg), len - 4); 105 if (atomicio(vwrite, mon->m_log_sendfd, 106 sshbuf_mutable_ptr(log_msg), len) != len) 107 fatal("%s: write: %s", __func__, strerror(errno)); 108 sshbuf_free(log_msg); 109 } 110 111 int 112 mm_is_monitor(void) 113 { 114 /* 115 * m_pid is only set in the privileged part, and 116 * points to the unprivileged child. 117 */ 118 return (pmonitor && pmonitor->m_pid > 0); 119 } 120 121 void 122 mm_request_send(int sock, enum monitor_reqtype type, struct sshbuf *m) 123 { 124 size_t mlen = sshbuf_len(m); 125 u_char buf[5]; 126 127 debug3("%s entering: type %d", __func__, type); 128 129 if (mlen >= 0xffffffff) 130 fatal("%s: bad length %zu", __func__, mlen); 131 POKE_U32(buf, mlen + 1); 132 buf[4] = (u_char) type; /* 1st byte of payload is mesg-type */ 133 if (atomicio(vwrite, sock, buf, sizeof(buf)) != sizeof(buf)) 134 fatal("%s: write: %s", __func__, strerror(errno)); 135 if (atomicio(vwrite, sock, sshbuf_mutable_ptr(m), mlen) != mlen) 136 fatal("%s: write: %s", __func__, strerror(errno)); 137 } 138 139 void 140 mm_request_receive(int sock, struct sshbuf *m) 141 { 142 u_char buf[4], *p = NULL; 143 u_int msg_len; 144 int r; 145 146 debug3("%s entering", __func__); 147 148 if (atomicio(read, sock, buf, sizeof(buf)) != sizeof(buf)) { 149 if (errno == EPIPE) 150 cleanup_exit(255); 151 fatal("%s: read: %s", __func__, strerror(errno)); 152 } 153 msg_len = PEEK_U32(buf); 154 if (msg_len > 256 * 1024) 155 fatal("%s: read: bad msg_len %d", __func__, msg_len); 156 sshbuf_reset(m); 157 if ((r = sshbuf_reserve(m, msg_len, &p)) != 0) 158 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 159 if (atomicio(read, sock, p, msg_len) != msg_len) 160 fatal("%s: read: %s", __func__, strerror(errno)); 161 } 162 163 void 164 mm_request_receive_expect(int sock, enum monitor_reqtype type, struct sshbuf *m) 165 { 166 u_char rtype; 167 int r; 168 169 debug3("%s entering: type %d", __func__, type); 170 171 mm_request_receive(sock, m); 172 if ((r = sshbuf_get_u8(m, &rtype)) != 0) 173 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 174 if (rtype != type) 175 fatal("%s: read: rtype %d != type %d", __func__, 176 rtype, type); 177 } 178 179 #ifdef WITH_OPENSSL 180 DH * 181 mm_choose_dh(int min, int nbits, int max) 182 { 183 BIGNUM *p, *g; 184 int r; 185 u_char success = 0; 186 struct sshbuf *m; 187 188 if ((m = sshbuf_new()) == NULL) 189 fatal("%s: sshbuf_new failed", __func__); 190 if ((r = sshbuf_put_u32(m, min)) != 0 || 191 (r = sshbuf_put_u32(m, nbits)) != 0 || 192 (r = sshbuf_put_u32(m, max)) != 0) 193 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 194 195 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_MODULI, m); 196 197 debug3("%s: waiting for MONITOR_ANS_MODULI", __func__); 198 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_MODULI, m); 199 200 if ((r = sshbuf_get_u8(m, &success)) != 0) 201 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 202 if (success == 0) 203 fatal("%s: MONITOR_ANS_MODULI failed", __func__); 204 205 if ((p = BN_new()) == NULL) 206 fatal("%s: BN_new failed", __func__); 207 if ((g = BN_new()) == NULL) 208 fatal("%s: BN_new failed", __func__); 209 if ((r = sshbuf_get_bignum2(m, p)) != 0 || 210 (r = sshbuf_get_bignum2(m, g)) != 0) 211 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 212 213 debug3("%s: remaining %zu", __func__, sshbuf_len(m)); 214 sshbuf_free(m); 215 216 return (dh_new_group(g, p)); 217 } 218 #endif 219 220 int 221 mm_sshkey_sign(struct sshkey *key, u_char **sigp, size_t *lenp, 222 const u_char *data, size_t datalen, const char *hostkey_alg, u_int compat) 223 { 224 struct kex *kex = *pmonitor->m_pkex; 225 struct sshbuf *m; 226 u_int ndx = kex->host_key_index(key, 0, active_state); 227 int r; 228 229 debug3("%s entering", __func__); 230 231 if ((m = sshbuf_new()) == NULL) 232 fatal("%s: sshbuf_new failed", __func__); 233 if ((r = sshbuf_put_u32(m, ndx)) != 0 || 234 (r = sshbuf_put_string(m, data, datalen)) != 0 || 235 (r = sshbuf_put_cstring(m, hostkey_alg)) != 0 || 236 (r = sshbuf_put_u32(m, compat)) != 0) 237 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 238 239 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, m); 240 241 debug3("%s: waiting for MONITOR_ANS_SIGN", __func__); 242 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, m); 243 if ((r = sshbuf_get_string(m, sigp, lenp)) != 0) 244 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 245 sshbuf_free(m); 246 247 return (0); 248 } 249 250 #ifdef HAVE_LOGIN_CAP 251 login_cap_t * 252 mm_login_getpwclass(const struct passwd *pwent) 253 { 254 int r; 255 struct sshbuf *m; 256 char rc; 257 login_cap_t *lc; 258 259 debug3("%s entering", __func__); 260 261 if ((m = sshbuf_new()) == NULL) 262 fatal("%s: sshbuf_new failed", __func__); 263 if ((r = sshbuf_put_passwd(m, pwent)) != 0) 264 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 265 266 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GETPWCLASS, m); 267 268 debug3("%s: waiting for MONITOR_ANS_GETPWCLASS", __func__); 269 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GETPWCLASS, m); 270 271 if ((r = sshbuf_get_u8(m, &rc)) != 0) 272 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 273 274 if (rc == 0) { 275 lc = NULL; 276 goto out; 277 } 278 279 lc = xmalloc(sizeof(*lc)); 280 if ((r = sshbuf_get_cstring(m, &lc->lc_class, NULL)) != 0 || 281 (r = sshbuf_get_cstring(m, &lc->lc_cap, NULL)) != 0 || 282 (r = sshbuf_get_cstring(m, &lc->lc_style, NULL)) != 0) 283 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 284 285 out: 286 sshbuf_free(m); 287 288 return (lc); 289 } 290 #endif 291 292 #ifdef HAVE_LOGIN_CAP 293 void 294 mm_login_close(login_cap_t *lc) 295 { 296 if (lc == NULL) 297 return; 298 free(lc->lc_style); 299 free(lc->lc_class); 300 free(lc->lc_cap); 301 free(lc); 302 } 303 #endif 304 305 struct passwd * 306 mm_getpwnamallow(const char *username) 307 { 308 struct ssh *ssh = active_state; /* XXX */ 309 struct sshbuf *m; 310 struct passwd *pw; 311 size_t len; 312 u_int i; 313 ServerOptions *newopts; 314 int r; 315 u_char ok; 316 const u_char *p; 317 318 debug3("%s entering", __func__); 319 320 if ((m = sshbuf_new()) == NULL) 321 fatal("%s: sshbuf_new failed", __func__); 322 if ((r = sshbuf_put_cstring(m, username)) != 0) 323 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 324 325 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, m); 326 327 debug3("%s: waiting for MONITOR_ANS_PWNAM", __func__); 328 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, m); 329 330 if ((r = sshbuf_get_u8(m, &ok)) != 0) 331 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 332 if (ok == 0) { 333 pw = NULL; 334 goto out; 335 } 336 337 pw = sshbuf_get_passwd(m); 338 if (pw == NULL) 339 fatal("%s: receive get struct passwd failed", __func__); 340 341 out: 342 /* copy options block as a Match directive may have changed some */ 343 if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0) 344 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 345 if (len != sizeof(*newopts)) 346 fatal("%s: option block size mismatch", __func__); 347 newopts = xcalloc(sizeof(*newopts), 1); 348 memcpy(newopts, p, sizeof(*newopts)); 349 350 #define M_CP_STROPT(x) do { \ 351 if (newopts->x != NULL) { \ 352 if ((r = sshbuf_get_cstring(m, \ 353 &newopts->x, NULL)) != 0) \ 354 fatal("%s: buffer error: %s", \ 355 __func__, ssh_err(r)); \ 356 } \ 357 } while (0) 358 #define M_CP_STRARRAYOPT(x, nx) do { \ 359 newopts->x = newopts->nx == 0 ? \ 360 NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \ 361 for (i = 0; i < newopts->nx; i++) { \ 362 if ((r = sshbuf_get_cstring(m, \ 363 &newopts->x[i], NULL)) != 0) \ 364 fatal("%s: buffer error: %s", \ 365 __func__, ssh_err(r)); \ 366 } \ 367 } while (0) 368 /* See comment in servconf.h */ 369 COPY_MATCH_STRING_OPTS(); 370 #undef M_CP_STROPT 371 #undef M_CP_STRARRAYOPT 372 373 copy_set_server_options(&options, newopts, 1); 374 log_change_level(options.log_level); 375 process_permitopen(ssh, &options); 376 free(newopts); 377 378 sshbuf_free(m); 379 380 return (pw); 381 } 382 383 char * 384 mm_auth2_read_banner(void) 385 { 386 struct sshbuf *m; 387 char *banner; 388 int r; 389 390 debug3("%s entering", __func__); 391 392 if ((m = sshbuf_new()) == NULL) 393 fatal("%s: sshbuf_new failed", __func__); 394 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, m); 395 sshbuf_reset(m); 396 397 mm_request_receive_expect(pmonitor->m_recvfd, 398 MONITOR_ANS_AUTH2_READ_BANNER, m); 399 if ((r = sshbuf_get_cstring(m, &banner, NULL)) != 0) 400 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 401 sshbuf_free(m); 402 403 /* treat empty banner as missing banner */ 404 if (strlen(banner) == 0) { 405 free(banner); 406 banner = NULL; 407 } 408 return (banner); 409 } 410 411 /* Inform the privileged process about service and style */ 412 413 void 414 mm_inform_authserv(char *service, char *style) 415 { 416 struct sshbuf *m; 417 int r; 418 419 debug3("%s entering", __func__); 420 421 if ((m = sshbuf_new()) == NULL) 422 fatal("%s: sshbuf_new failed", __func__); 423 if ((r = sshbuf_put_cstring(m, service)) != 0 || 424 (r = sshbuf_put_cstring(m, style ? style : "")) != 0) 425 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 426 427 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, m); 428 429 sshbuf_free(m); 430 } 431 432 /* Do the password authentication */ 433 int 434 mm_auth_password(struct ssh *ssh, char *password) 435 { 436 struct sshbuf *m; 437 int r, authenticated = 0; 438 #ifdef USE_PAM 439 u_int maxtries = 0; 440 #endif 441 442 debug3("%s entering", __func__); 443 444 if ((m = sshbuf_new()) == NULL) 445 fatal("%s: sshbuf_new failed", __func__); 446 if ((r = sshbuf_put_cstring(m, password)) != 0) 447 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 448 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, m); 449 450 debug3("%s: waiting for MONITOR_ANS_AUTHPASSWORD", __func__); 451 mm_request_receive_expect(pmonitor->m_recvfd, 452 MONITOR_ANS_AUTHPASSWORD, m); 453 454 if ((r = sshbuf_get_u32(m, &authenticated)) != 0) 455 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 456 #ifdef USE_PAM 457 if ((r = sshbuf_get_u32(m, &maxtries)) != 0) 458 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 459 if (maxtries > INT_MAX) 460 fatal("%s: bad maxtries %u", __func__, maxtries); 461 sshpam_set_maxtries_reached(maxtries); 462 #endif 463 464 sshbuf_free(m); 465 466 debug3("%s: user %sauthenticated", 467 __func__, authenticated ? "" : "not "); 468 return (authenticated); 469 } 470 471 int 472 mm_user_key_allowed(struct ssh *ssh, struct passwd *pw, struct sshkey *key, 473 int pubkey_auth_attempt, struct sshauthopt **authoptp) 474 { 475 return (mm_key_allowed(MM_USERKEY, NULL, NULL, key, 476 pubkey_auth_attempt, authoptp)); 477 } 478 479 int 480 mm_hostbased_key_allowed(struct passwd *pw, const char *user, const char *host, 481 struct sshkey *key) 482 { 483 return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0, NULL)); 484 } 485 486 int 487 mm_key_allowed(enum mm_keytype type, const char *user, const char *host, 488 struct sshkey *key, int pubkey_auth_attempt, struct sshauthopt **authoptp) 489 { 490 struct sshbuf *m; 491 int r, allowed = 0; 492 struct sshauthopt *opts = NULL; 493 494 debug3("%s entering", __func__); 495 496 if (authoptp != NULL) 497 *authoptp = NULL; 498 499 if ((m = sshbuf_new()) == NULL) 500 fatal("%s: sshbuf_new failed", __func__); 501 if ((r = sshbuf_put_u32(m, type)) != 0 || 502 (r = sshbuf_put_cstring(m, user ? user : "")) != 0 || 503 (r = sshbuf_put_cstring(m, host ? host : "")) != 0 || 504 (r = sshkey_puts(key, m)) != 0 || 505 (r = sshbuf_put_u32(m, pubkey_auth_attempt)) != 0) 506 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 507 508 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, m); 509 510 debug3("%s: waiting for MONITOR_ANS_KEYALLOWED", __func__); 511 mm_request_receive_expect(pmonitor->m_recvfd, 512 MONITOR_ANS_KEYALLOWED, m); 513 514 if ((r = sshbuf_get_u32(m, &allowed)) != 0) 515 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 516 if (allowed && type == MM_USERKEY) { 517 if ((r = sshauthopt_deserialise(m, &opts)) != 0) 518 fatal("%s: sshauthopt_deserialise: %s", 519 __func__, ssh_err(r)); 520 } 521 sshbuf_free(m); 522 523 if (authoptp != NULL) { 524 *authoptp = opts; 525 opts = NULL; 526 } 527 sshauthopt_free(opts); 528 529 return allowed; 530 } 531 532 /* 533 * This key verify needs to send the key type along, because the 534 * privileged parent makes the decision if the key is allowed 535 * for authentication. 536 */ 537 538 int 539 mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen, 540 const u_char *data, size_t datalen, const char *sigalg, u_int compat) 541 { 542 struct sshbuf *m; 543 u_int encoded_ret = 0; 544 int r; 545 546 debug3("%s entering", __func__); 547 548 549 if ((m = sshbuf_new()) == NULL) 550 fatal("%s: sshbuf_new failed", __func__); 551 if ((r = sshkey_puts(key, m)) != 0 || 552 (r = sshbuf_put_string(m, sig, siglen)) != 0 || 553 (r = sshbuf_put_string(m, data, datalen)) != 0 || 554 (r = sshbuf_put_cstring(m, sigalg == NULL ? "" : sigalg)) != 0) 555 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 556 557 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, m); 558 559 debug3("%s: waiting for MONITOR_ANS_KEYVERIFY", __func__); 560 mm_request_receive_expect(pmonitor->m_recvfd, 561 MONITOR_ANS_KEYVERIFY, m); 562 563 if ((r = sshbuf_get_u32(m, &encoded_ret)) != 0) 564 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 565 566 sshbuf_free(m); 567 568 if (encoded_ret != 0) 569 return SSH_ERR_SIGNATURE_INVALID; 570 return 0; 571 } 572 573 void 574 mm_send_keystate(struct monitor *monitor) 575 { 576 struct ssh *ssh = active_state; /* XXX */ 577 struct sshbuf *m; 578 int r; 579 580 if ((m = sshbuf_new()) == NULL) 581 fatal("%s: sshbuf_new failed", __func__); 582 if ((r = ssh_packet_get_state(ssh, m)) != 0) 583 fatal("%s: get_state failed: %s", 584 __func__, ssh_err(r)); 585 mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m); 586 debug3("%s: Finished sending state", __func__); 587 sshbuf_free(m); 588 } 589 590 int 591 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen) 592 { 593 struct sshbuf *m; 594 char *p, *msg; 595 int success = 0, tmp1 = -1, tmp2 = -1, r; 596 597 /* Kludge: ensure there are fds free to receive the pty/tty */ 598 if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 || 599 (tmp2 = dup(pmonitor->m_recvfd)) == -1) { 600 error("%s: cannot allocate fds for pty", __func__); 601 if (tmp1 > 0) 602 close(tmp1); 603 if (tmp2 > 0) 604 close(tmp2); 605 return 0; 606 } 607 close(tmp1); 608 close(tmp2); 609 610 if ((m = sshbuf_new()) == NULL) 611 fatal("%s: sshbuf_new failed", __func__); 612 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, m); 613 614 debug3("%s: waiting for MONITOR_ANS_PTY", __func__); 615 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, m); 616 617 if ((r = sshbuf_get_u32(m, &success)) != 0) 618 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 619 if (success == 0) { 620 debug3("%s: pty alloc failed", __func__); 621 sshbuf_free(m); 622 return (0); 623 } 624 if ((r = sshbuf_get_cstring(m, &p, NULL)) != 0 || 625 (r = sshbuf_get_cstring(m, &msg, NULL)) != 0) 626 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 627 sshbuf_free(m); 628 629 strlcpy(namebuf, p, namebuflen); /* Possible truncation */ 630 free(p); 631 632 if ((r = sshbuf_put(loginmsg, msg, strlen(msg))) != 0) 633 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 634 free(msg); 635 636 if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 || 637 (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1) 638 fatal("%s: receive fds failed", __func__); 639 640 /* Success */ 641 return (1); 642 } 643 644 void 645 mm_session_pty_cleanup2(Session *s) 646 { 647 struct sshbuf *m; 648 int r; 649 650 if (s->ttyfd == -1) 651 return; 652 if ((m = sshbuf_new()) == NULL) 653 fatal("%s: sshbuf_new failed", __func__); 654 if ((r = sshbuf_put_cstring(m, s->tty)) != 0) 655 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 656 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, m); 657 sshbuf_free(m); 658 659 /* closed dup'ed master */ 660 if (s->ptymaster != -1 && close(s->ptymaster) < 0) 661 error("close(s->ptymaster/%d): %s", 662 s->ptymaster, strerror(errno)); 663 664 /* unlink pty from session */ 665 s->ttyfd = -1; 666 } 667 668 #ifdef USE_PAM 669 void 670 mm_start_pam(Authctxt *authctxt) 671 { 672 struct sshbuf *m; 673 674 debug3("%s entering", __func__); 675 if (!options.use_pam) 676 fatal("UsePAM=no, but ended up in %s anyway", __func__); 677 if ((m = sshbuf_new()) == NULL) 678 fatal("%s: sshbuf_new failed", __func__); 679 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, m); 680 681 sshbuf_free(m); 682 } 683 684 u_int 685 mm_do_pam_account(void) 686 { 687 struct sshbuf *m; 688 u_int ret; 689 char *msg; 690 size_t msglen; 691 int r; 692 693 debug3("%s entering", __func__); 694 if (!options.use_pam) 695 fatal("UsePAM=no, but ended up in %s anyway", __func__); 696 697 if ((m = sshbuf_new()) == NULL) 698 fatal("%s: sshbuf_new failed", __func__); 699 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, m); 700 701 mm_request_receive_expect(pmonitor->m_recvfd, 702 MONITOR_ANS_PAM_ACCOUNT, m); 703 if ((r = sshbuf_get_u32(m, &ret)) != 0 || 704 (r = sshbuf_get_cstring(m, &msg, &msglen)) != 0 || 705 (r = sshbuf_put(loginmsg, msg, msglen)) != 0) 706 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 707 708 free(msg); 709 sshbuf_free(m); 710 711 debug3("%s returning %d", __func__, ret); 712 713 return (ret); 714 } 715 716 void * 717 mm_sshpam_init_ctx(Authctxt *authctxt) 718 { 719 struct sshbuf *m; 720 int r, success; 721 722 debug3("%s", __func__); 723 if ((m = sshbuf_new()) == NULL) 724 fatal("%s: sshbuf_new failed", __func__); 725 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, m); 726 debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__); 727 mm_request_receive_expect(pmonitor->m_recvfd, 728 MONITOR_ANS_PAM_INIT_CTX, m); 729 if ((r = sshbuf_get_u32(m, &success)) != 0) 730 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 731 if (success == 0) { 732 debug3("%s: pam_init_ctx failed", __func__); 733 sshbuf_free(m); 734 return (NULL); 735 } 736 sshbuf_free(m); 737 return (authctxt); 738 } 739 740 int 741 mm_sshpam_query(void *ctx, char **name, char **info, 742 u_int *num, char ***prompts, u_int **echo_on) 743 { 744 struct sshbuf *m; 745 u_int i, n; 746 int r, ret; 747 748 debug3("%s", __func__); 749 if ((m = sshbuf_new()) == NULL) 750 fatal("%s: sshbuf_new failed", __func__); 751 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_QUERY, m); 752 debug3("%s: waiting for MONITOR_ANS_PAM_QUERY", __func__); 753 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_QUERY, m); 754 if ((r = sshbuf_get_u32(m, &ret)) != 0 || 755 (r = sshbuf_get_cstring(m, name, NULL)) != 0 || 756 (r = sshbuf_get_cstring(m, info, NULL)) != 0 || 757 (r = sshbuf_get_u32(m, &n)) != 0 || 758 (r = sshbuf_get_u32(m, num)) != 0) 759 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 760 debug3("%s: pam_query returned %d", __func__, ret); 761 sshpam_set_maxtries_reached(n); 762 if (*num > PAM_MAX_NUM_MSG) 763 fatal("%s: received %u PAM messages, expected <= %u", 764 __func__, *num, PAM_MAX_NUM_MSG); 765 *prompts = xcalloc((*num + 1), sizeof(char *)); 766 *echo_on = xcalloc((*num + 1), sizeof(u_int)); 767 for (i = 0; i < *num; ++i) { 768 if ((r = sshbuf_get_cstring(m, &((*prompts)[i]), NULL)) != 0 || 769 (r = sshbuf_get_u32(m, &((*echo_on)[i]))) != 0) 770 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 771 } 772 sshbuf_free(m); 773 return (ret); 774 } 775 776 int 777 mm_sshpam_respond(void *ctx, u_int num, char **resp) 778 { 779 struct sshbuf *m; 780 u_int n, i; 781 int r, ret; 782 783 debug3("%s", __func__); 784 if ((m = sshbuf_new()) == NULL) 785 fatal("%s: sshbuf_new failed", __func__); 786 if ((r = sshbuf_put_u32(m, num)) != 0) 787 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 788 for (i = 0; i < num; ++i) { 789 if ((r = sshbuf_put_cstring(m, resp[i])) != 0) 790 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 791 } 792 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, m); 793 debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__); 794 mm_request_receive_expect(pmonitor->m_recvfd, 795 MONITOR_ANS_PAM_RESPOND, m); 796 if ((r = sshbuf_get_u32(m, &n)) != 0) 797 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 798 ret = (int)n; /* XXX */ 799 debug3("%s: pam_respond returned %d", __func__, ret); 800 sshbuf_free(m); 801 return (ret); 802 } 803 804 void 805 mm_sshpam_free_ctx(void *ctxtp) 806 { 807 struct sshbuf *m; 808 809 debug3("%s", __func__); 810 if ((m = sshbuf_new()) == NULL) 811 fatal("%s: sshbuf_new failed", __func__); 812 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_FREE_CTX, m); 813 debug3("%s: waiting for MONITOR_ANS_PAM_FREE_CTX", __func__); 814 mm_request_receive_expect(pmonitor->m_recvfd, 815 MONITOR_ANS_PAM_FREE_CTX, m); 816 sshbuf_free(m); 817 } 818 #endif /* USE_PAM */ 819 820 /* Request process termination */ 821 822 void 823 mm_terminate(void) 824 { 825 struct sshbuf *m; 826 827 if ((m = sshbuf_new()) == NULL) 828 fatal("%s: sshbuf_new failed", __func__); 829 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, m); 830 sshbuf_free(m); 831 } 832 833 static void 834 mm_chall_setup(char **name, char **infotxt, u_int *numprompts, 835 char ***prompts, u_int **echo_on) 836 { 837 *name = xstrdup(""); 838 *infotxt = xstrdup(""); 839 *numprompts = 1; 840 *prompts = xcalloc(*numprompts, sizeof(char *)); 841 *echo_on = xcalloc(*numprompts, sizeof(u_int)); 842 (*echo_on)[0] = 0; 843 } 844 845 int 846 mm_bsdauth_query(void *ctx, char **name, char **infotxt, 847 u_int *numprompts, char ***prompts, u_int **echo_on) 848 { 849 struct sshbuf *m; 850 u_int success; 851 char *challenge; 852 int r; 853 854 debug3("%s: entering", __func__); 855 856 if ((m = sshbuf_new()) == NULL) 857 fatal("%s: sshbuf_new failed", __func__); 858 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, m); 859 860 mm_request_receive_expect(pmonitor->m_recvfd, 861 MONITOR_ANS_BSDAUTHQUERY, m); 862 if ((r = sshbuf_get_u32(m, &success)) != 0) 863 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 864 if (success == 0) { 865 debug3("%s: no challenge", __func__); 866 sshbuf_free(m); 867 return (-1); 868 } 869 870 /* Get the challenge, and format the response */ 871 if ((r = sshbuf_get_cstring(m, &challenge, NULL)) != 0) 872 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 873 sshbuf_free(m); 874 875 mm_chall_setup(name, infotxt, numprompts, prompts, echo_on); 876 (*prompts)[0] = challenge; 877 878 debug3("%s: received challenge: %s", __func__, challenge); 879 880 return (0); 881 } 882 883 int 884 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses) 885 { 886 struct sshbuf *m; 887 int r, authok; 888 889 debug3("%s: entering", __func__); 890 if (numresponses != 1) 891 return (-1); 892 893 if ((m = sshbuf_new()) == NULL) 894 fatal("%s: sshbuf_new failed", __func__); 895 if ((r = sshbuf_put_cstring(m, responses[0])) != 0) 896 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 897 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, m); 898 899 mm_request_receive_expect(pmonitor->m_recvfd, 900 MONITOR_ANS_BSDAUTHRESPOND, m); 901 902 if ((r = sshbuf_get_u32(m, &authok)) != 0) 903 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 904 sshbuf_free(m); 905 906 return ((authok == 0) ? -1 : 0); 907 } 908 909 #ifdef SSH_AUDIT_EVENTS 910 void 911 mm_audit_event(ssh_audit_event_t event) 912 { 913 struct sshbuf *m; 914 int r; 915 916 debug3("%s entering", __func__); 917 918 if ((m = sshbuf_new()) == NULL) 919 fatal("%s: sshbuf_new failed", __func__); 920 if ((r = sshbuf_put_u32(m, event)) != 0) 921 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 922 923 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_EVENT, m); 924 sshbuf_free(m); 925 } 926 927 void 928 mm_audit_run_command(const char *command) 929 { 930 struct sshbuf *m; 931 int r; 932 933 debug3("%s entering command %s", __func__, command); 934 935 if ((m = sshbuf_new()) == NULL) 936 fatal("%s: sshbuf_new failed", __func__); 937 if ((r = sshbuf_put_cstring(m, command)) != 0) 938 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 939 940 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_COMMAND, m); 941 sshbuf_free(m); 942 } 943 #endif /* SSH_AUDIT_EVENTS */ 944 945 #ifdef GSSAPI 946 OM_uint32 947 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid) 948 { 949 struct sshbuf *m; 950 OM_uint32 major; 951 int r; 952 953 /* Client doesn't get to see the context */ 954 *ctx = NULL; 955 956 if ((m = sshbuf_new()) == NULL) 957 fatal("%s: sshbuf_new failed", __func__); 958 if ((r = sshbuf_put_string(m, goid->elements, goid->length)) != 0) 959 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 960 961 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, m); 962 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, m); 963 964 if ((r = sshbuf_get_u32(m, &major)) != 0) 965 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 966 967 sshbuf_free(m); 968 return (major); 969 } 970 971 OM_uint32 972 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in, 973 gss_buffer_desc *out, OM_uint32 *flagsp) 974 { 975 struct sshbuf *m; 976 OM_uint32 major; 977 u_int flags; 978 int r; 979 980 if ((m = sshbuf_new()) == NULL) 981 fatal("%s: sshbuf_new failed", __func__); 982 if ((r = sshbuf_put_string(m, in->value, in->length)) != 0) 983 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 984 985 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, m); 986 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, m); 987 988 if ((r = sshbuf_get_u32(m, &major)) != 0 || 989 (r = ssh_gssapi_get_buffer_desc(m, out)) != 0) 990 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 991 if (flagsp != NULL) { 992 if ((r = sshbuf_get_u32(m, &flags)) != 0) 993 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 994 *flagsp = flags; 995 } 996 997 sshbuf_free(m); 998 999 return (major); 1000 } 1001 1002 OM_uint32 1003 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) 1004 { 1005 struct sshbuf *m; 1006 OM_uint32 major; 1007 int r; 1008 1009 if ((m = sshbuf_new()) == NULL) 1010 fatal("%s: sshbuf_new failed", __func__); 1011 if ((r = sshbuf_put_string(m, gssbuf->value, gssbuf->length)) != 0 || 1012 (r = sshbuf_put_string(m, gssmic->value, gssmic->length)) != 0) 1013 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1014 1015 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, m); 1016 mm_request_receive_expect(pmonitor->m_recvfd, 1017 MONITOR_ANS_GSSCHECKMIC, m); 1018 1019 if ((r = sshbuf_get_u32(m, &major)) != 0) 1020 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1021 sshbuf_free(m); 1022 return(major); 1023 } 1024 1025 int 1026 mm_ssh_gssapi_userok(char *user) 1027 { 1028 struct sshbuf *m; 1029 int r, authenticated = 0; 1030 1031 if ((m = sshbuf_new()) == NULL) 1032 fatal("%s: sshbuf_new failed", __func__); 1033 1034 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, m); 1035 mm_request_receive_expect(pmonitor->m_recvfd, 1036 MONITOR_ANS_GSSUSEROK, m); 1037 1038 if ((r = sshbuf_get_u32(m, &authenticated)) != 0) 1039 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1040 1041 sshbuf_free(m); 1042 debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not "); 1043 return (authenticated); 1044 } 1045 #endif /* GSSAPI */ 1046