1 /* $NetBSD: monitor_wrap.c,v 1.25 2019/04/20 17:16:40 christos Exp $ */ 2 /* $OpenBSD: monitor_wrap.c,v 1.112 2019/01/21 09:54:11 djm Exp $ */ 3 /* 4 * Copyright 2002 Niels Provos <provos@citi.umich.edu> 5 * Copyright 2002 Markus Friedl <markus@openbsd.org> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include "includes.h" 30 __RCSID("$NetBSD: monitor_wrap.c,v 1.25 2019/04/20 17:16:40 christos Exp $"); 31 #include <sys/types.h> 32 #include <sys/uio.h> 33 #include <sys/queue.h> 34 35 #include <errno.h> 36 #include <pwd.h> 37 #include <signal.h> 38 #include <stdio.h> 39 #include <string.h> 40 #include <unistd.h> 41 42 #ifdef WITH_OPENSSL 43 #include <openssl/bn.h> 44 #include <openssl/dh.h> 45 #endif 46 47 #include "xmalloc.h" 48 #include "ssh.h" 49 #ifdef WITH_OPENSSL 50 #include "dh.h" 51 #endif 52 #include "sshbuf.h" 53 #include "sshkey.h" 54 #include "cipher.h" 55 #include "kex.h" 56 #include "hostfile.h" 57 #include "auth.h" 58 #include "auth-options.h" 59 #include "packet.h" 60 #include "mac.h" 61 #include "log.h" 62 #include "monitor.h" 63 #ifdef GSSAPI 64 #include "ssh-gss.h" 65 #endif 66 #include "monitor_wrap.h" 67 #include "atomicio.h" 68 #include "monitor_fdpass.h" 69 #ifdef USE_PAM 70 #include "misc.h" 71 #include "servconf.h" 72 #include <security/pam_appl.h> 73 #endif 74 #include "misc.h" 75 76 #include "channels.h" 77 #include "session.h" 78 #include "servconf.h" 79 80 #include "ssherr.h" 81 82 /* Imports */ 83 extern struct monitor *pmonitor; 84 extern struct sshbuf *loginmsg; 85 extern ServerOptions options; 86 87 void 88 mm_log_handler(LogLevel level, const char *msg, void *ctx) 89 { 90 struct sshbuf *log_msg; 91 struct monitor *mon = (struct monitor *)ctx; 92 int r; 93 size_t len; 94 95 if (mon->m_log_sendfd == -1) 96 fatal("%s: no log channel", __func__); 97 98 if ((log_msg = sshbuf_new()) == NULL) 99 fatal("%s: sshbuf_new failed", __func__); 100 101 if ((r = sshbuf_put_u32(log_msg, 0)) != 0 || /* length; filled below */ 102 (r = sshbuf_put_u32(log_msg, level)) != 0 || 103 (r = sshbuf_put_cstring(log_msg, msg)) != 0) 104 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 105 if ((len = sshbuf_len(log_msg)) < 4 || len > 0xffffffff) 106 fatal("%s: bad length %zu", __func__, len); 107 POKE_U32(sshbuf_mutable_ptr(log_msg), len - 4); 108 if (atomicio(vwrite, mon->m_log_sendfd, 109 sshbuf_mutable_ptr(log_msg), len) != len) 110 fatal("%s: write: %s", __func__, strerror(errno)); 111 sshbuf_free(log_msg); 112 } 113 114 int 115 mm_is_monitor(void) 116 { 117 /* 118 * m_pid is only set in the privileged part, and 119 * points to the unprivileged child. 120 */ 121 return (pmonitor && pmonitor->m_pid > 0); 122 } 123 124 void 125 mm_request_send(int sock, enum monitor_reqtype type, struct sshbuf *m) 126 { 127 size_t mlen = sshbuf_len(m); 128 u_char buf[5]; 129 130 debug3("%s entering: type %d", __func__, type); 131 132 if (mlen >= 0xffffffff) 133 fatal("%s: bad length %zu", __func__, mlen); 134 POKE_U32(buf, mlen + 1); 135 buf[4] = (u_char) type; /* 1st byte of payload is mesg-type */ 136 if (atomicio(vwrite, sock, buf, sizeof(buf)) != sizeof(buf)) 137 fatal("%s: write: %s", __func__, strerror(errno)); 138 if (atomicio(vwrite, sock, sshbuf_mutable_ptr(m), mlen) != mlen) 139 fatal("%s: write: %s", __func__, strerror(errno)); 140 } 141 142 void 143 mm_request_receive(int sock, struct sshbuf *m) 144 { 145 u_char buf[4], *p = NULL; 146 u_int msg_len; 147 int r; 148 149 debug3("%s entering", __func__); 150 151 if (atomicio(read, sock, buf, sizeof(buf)) != sizeof(buf)) { 152 if (errno == EPIPE) 153 cleanup_exit(254); 154 fatal("%s: read: %s", __func__, strerror(errno)); 155 } 156 msg_len = PEEK_U32(buf); 157 if (msg_len > 256 * 1024) 158 fatal("%s: read: bad msg_len %d", __func__, msg_len); 159 sshbuf_reset(m); 160 if ((r = sshbuf_reserve(m, msg_len, &p)) != 0) 161 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 162 if (atomicio(read, sock, p, msg_len) != msg_len) 163 fatal("%s: read: %s", __func__, strerror(errno)); 164 } 165 166 void 167 mm_request_receive_expect(int sock, enum monitor_reqtype type, struct sshbuf *m) 168 { 169 u_char rtype; 170 int r; 171 172 debug3("%s entering: type %d", __func__, type); 173 174 mm_request_receive(sock, m); 175 if ((r = sshbuf_get_u8(m, &rtype)) != 0) 176 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 177 if (rtype != type) 178 fatal("%s: read: rtype %d != type %d", __func__, 179 rtype, type); 180 } 181 182 #ifdef WITH_OPENSSL 183 DH * 184 mm_choose_dh(int min, int nbits, int max) 185 { 186 BIGNUM *p, *g; 187 int r; 188 u_char success = 0; 189 struct sshbuf *m; 190 191 if ((m = sshbuf_new()) == NULL) 192 fatal("%s: sshbuf_new failed", __func__); 193 if ((r = sshbuf_put_u32(m, min)) != 0 || 194 (r = sshbuf_put_u32(m, nbits)) != 0 || 195 (r = sshbuf_put_u32(m, max)) != 0) 196 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 197 198 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_MODULI, m); 199 200 debug3("%s: waiting for MONITOR_ANS_MODULI", __func__); 201 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_MODULI, m); 202 203 if ((r = sshbuf_get_u8(m, &success)) != 0) 204 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 205 if (success == 0) 206 fatal("%s: MONITOR_ANS_MODULI failed", __func__); 207 208 if ((r = sshbuf_get_bignum2(m, &p)) != 0 || 209 (r = sshbuf_get_bignum2(m, &g)) != 0) 210 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 211 212 debug3("%s: remaining %zu", __func__, sshbuf_len(m)); 213 sshbuf_free(m); 214 215 return (dh_new_group(g, p)); 216 } 217 #endif 218 219 int 220 mm_sshkey_sign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp, 221 const u_char *data, size_t datalen, const char *hostkey_alg, u_int compat) 222 { 223 struct kex *kex = *pmonitor->m_pkex; 224 struct sshbuf *m; 225 u_int ndx = kex->host_key_index(key, 0, ssh); 226 int r; 227 228 debug3("%s entering", __func__); 229 230 if ((m = sshbuf_new()) == NULL) 231 fatal("%s: sshbuf_new failed", __func__); 232 if ((r = sshbuf_put_u32(m, ndx)) != 0 || 233 (r = sshbuf_put_string(m, data, datalen)) != 0 || 234 (r = sshbuf_put_cstring(m, hostkey_alg)) != 0 || 235 (r = sshbuf_put_u32(m, compat)) != 0) 236 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 237 238 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, m); 239 240 debug3("%s: waiting for MONITOR_ANS_SIGN", __func__); 241 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, m); 242 if ((r = sshbuf_get_string(m, sigp, lenp)) != 0) 243 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 244 sshbuf_free(m); 245 246 return (0); 247 } 248 249 struct passwd * 250 mm_getpwnamallow(struct ssh *ssh, const char *username) 251 { 252 struct sshbuf *m; 253 struct passwd *pw; 254 size_t len; 255 u_int i; 256 ServerOptions *newopts; 257 int r; 258 u_char ok; 259 const u_char *p; 260 261 debug3("%s entering", __func__); 262 263 if ((m = sshbuf_new()) == NULL) 264 fatal("%s: sshbuf_new failed", __func__); 265 if ((r = sshbuf_put_cstring(m, username)) != 0) 266 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 267 268 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, m); 269 270 debug3("%s: waiting for MONITOR_ANS_PWNAM", __func__); 271 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, m); 272 273 if ((r = sshbuf_get_u8(m, &ok)) != 0) 274 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 275 if (ok == 0) { 276 pw = NULL; 277 goto out; 278 } 279 280 /* XXX don't like passing struct passwd like this */ 281 pw = xcalloc(sizeof(*pw), 1); 282 if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0) 283 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 284 if (len != sizeof(*pw)) 285 fatal("%s: struct passwd size mismatch", __func__); 286 memcpy(pw, p, sizeof(*pw)); 287 288 if ((r = sshbuf_get_cstring(m, &pw->pw_name, NULL)) != 0 || 289 (r = sshbuf_get_cstring(m, &pw->pw_passwd, NULL)) != 0 || 290 (r = sshbuf_get_cstring(m, &pw->pw_gecos, NULL)) != 0 || 291 (r = sshbuf_get_cstring(m, &pw->pw_class, NULL)) != 0 || 292 (r = sshbuf_get_cstring(m, &pw->pw_dir, NULL)) != 0 || 293 (r = sshbuf_get_cstring(m, &pw->pw_shell, NULL)) != 0) 294 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 295 296 out: 297 /* copy options block as a Match directive may have changed some */ 298 if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0) 299 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 300 if (len != sizeof(*newopts)) 301 fatal("%s: option block size mismatch", __func__); 302 newopts = xcalloc(sizeof(*newopts), 1); 303 memcpy(newopts, p, sizeof(*newopts)); 304 305 #define M_CP_STROPT(x) do { \ 306 if (newopts->x != NULL) { \ 307 if ((r = sshbuf_get_cstring(m, \ 308 &newopts->x, NULL)) != 0) \ 309 fatal("%s: buffer error: %s", \ 310 __func__, ssh_err(r)); \ 311 } \ 312 } while (0) 313 #define M_CP_STRARRAYOPT(x, nx) do { \ 314 newopts->x = newopts->nx == 0 ? \ 315 NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \ 316 for (i = 0; i < newopts->nx; i++) { \ 317 if ((r = sshbuf_get_cstring(m, \ 318 &newopts->x[i], NULL)) != 0) \ 319 fatal("%s: buffer error: %s", \ 320 __func__, ssh_err(r)); \ 321 } \ 322 } while (0) 323 /* See comment in servconf.h */ 324 COPY_MATCH_STRING_OPTS(); 325 #undef M_CP_STROPT 326 #undef M_CP_STRARRAYOPT 327 328 copy_set_server_options(&options, newopts, 1); 329 log_change_level(options.log_level); 330 process_permitopen(ssh, &options); 331 free(newopts); 332 333 sshbuf_free(m); 334 335 return (pw); 336 } 337 338 char * 339 mm_auth2_read_banner(void) 340 { 341 struct sshbuf *m; 342 char *banner; 343 int r; 344 345 debug3("%s entering", __func__); 346 347 if ((m = sshbuf_new()) == NULL) 348 fatal("%s: sshbuf_new failed", __func__); 349 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, m); 350 sshbuf_reset(m); 351 352 mm_request_receive_expect(pmonitor->m_recvfd, 353 MONITOR_ANS_AUTH2_READ_BANNER, m); 354 if ((r = sshbuf_get_cstring(m, &banner, NULL)) != 0) 355 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 356 sshbuf_free(m); 357 358 /* treat empty banner as missing banner */ 359 if (strlen(banner) == 0) { 360 free(banner); 361 banner = NULL; 362 } 363 return (banner); 364 } 365 366 /* Inform the privileged process about service and style */ 367 368 void 369 mm_inform_authserv(char *service, char *style) 370 { 371 struct sshbuf *m; 372 int r; 373 374 debug3("%s entering", __func__); 375 376 if ((m = sshbuf_new()) == NULL) 377 fatal("%s: sshbuf_new failed", __func__); 378 if ((r = sshbuf_put_cstring(m, service)) != 0 || 379 (r = sshbuf_put_cstring(m, style ? style : "")) != 0) 380 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 381 382 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, m); 383 384 sshbuf_free(m); 385 } 386 387 /* Do the password authentication */ 388 int 389 mm_auth_password(struct ssh *ssh, const char *password) 390 { 391 struct sshbuf *m; 392 int r; 393 u_int authenticated = 0; 394 395 debug3("%s entering", __func__); 396 397 if ((m = sshbuf_new()) == NULL) 398 fatal("%s: sshbuf_new failed", __func__); 399 if ((r = sshbuf_put_cstring(m, password)) != 0) 400 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 401 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, m); 402 403 debug3("%s: waiting for MONITOR_ANS_AUTHPASSWORD", __func__); 404 mm_request_receive_expect(pmonitor->m_recvfd, 405 MONITOR_ANS_AUTHPASSWORD, m); 406 407 if ((r = sshbuf_get_u32(m, &authenticated)) != 0) 408 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 409 410 sshbuf_free(m); 411 412 debug3("%s: user %sauthenticated", 413 __func__, authenticated ? "" : "not "); 414 return (authenticated); 415 } 416 417 int 418 mm_user_key_allowed(struct ssh *ssh, struct passwd *pw, struct sshkey *key, 419 int pubkey_auth_attempt, struct sshauthopt **authoptp) 420 { 421 return (mm_key_allowed(MM_USERKEY, NULL, NULL, key, 422 pubkey_auth_attempt, authoptp)); 423 } 424 425 int 426 mm_hostbased_key_allowed(struct ssh *ssh, struct passwd *pw, 427 const char *user, const char *host, struct sshkey *key) 428 { 429 return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0, NULL)); 430 } 431 432 int 433 mm_key_allowed(enum mm_keytype type, const char *user, const char *host, 434 struct sshkey *key, int pubkey_auth_attempt, struct sshauthopt **authoptp) 435 { 436 struct sshbuf *m; 437 int r; 438 u_int allowed = 0; 439 struct sshauthopt *opts = NULL; 440 441 debug3("%s entering", __func__); 442 443 if (authoptp != NULL) 444 *authoptp = NULL; 445 446 if ((m = sshbuf_new()) == NULL) 447 fatal("%s: sshbuf_new failed", __func__); 448 if ((r = sshbuf_put_u32(m, type)) != 0 || 449 (r = sshbuf_put_cstring(m, user ? user : "")) != 0 || 450 (r = sshbuf_put_cstring(m, host ? host : "")) != 0 || 451 (r = sshkey_puts(key, m)) != 0 || 452 (r = sshbuf_put_u32(m, pubkey_auth_attempt)) != 0) 453 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 454 455 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, m); 456 457 debug3("%s: waiting for MONITOR_ANS_KEYALLOWED", __func__); 458 mm_request_receive_expect(pmonitor->m_recvfd, 459 MONITOR_ANS_KEYALLOWED, m); 460 461 if ((r = sshbuf_get_u32(m, &allowed)) != 0) 462 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 463 if (allowed && type == MM_USERKEY) { 464 if ((r = sshauthopt_deserialise(m, &opts)) != 0) 465 fatal("%s: sshauthopt_deserialise: %s", 466 __func__, ssh_err(r)); 467 } 468 sshbuf_free(m); 469 470 if (authoptp != NULL) { 471 *authoptp = opts; 472 opts = NULL; 473 } 474 sshauthopt_free(opts); 475 476 return allowed; 477 } 478 479 /* 480 * This key verify needs to send the key type along, because the 481 * privileged parent makes the decision if the key is allowed 482 * for authentication. 483 */ 484 485 int 486 mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen, 487 const u_char *data, size_t datalen, const char *sigalg, u_int compat) 488 { 489 struct sshbuf *m; 490 u_int encoded_ret = 0; 491 int r; 492 493 debug3("%s entering", __func__); 494 495 496 if ((m = sshbuf_new()) == NULL) 497 fatal("%s: sshbuf_new failed", __func__); 498 if ((r = sshkey_puts(key, m)) != 0 || 499 (r = sshbuf_put_string(m, sig, siglen)) != 0 || 500 (r = sshbuf_put_string(m, data, datalen)) != 0 || 501 (r = sshbuf_put_cstring(m, sigalg == NULL ? "" : sigalg)) != 0) 502 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 503 504 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, m); 505 506 debug3("%s: waiting for MONITOR_ANS_KEYVERIFY", __func__); 507 mm_request_receive_expect(pmonitor->m_recvfd, 508 MONITOR_ANS_KEYVERIFY, m); 509 510 if ((r = sshbuf_get_u32(m, &encoded_ret)) != 0) 511 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 512 513 sshbuf_free(m); 514 515 if (encoded_ret != 0) 516 return SSH_ERR_SIGNATURE_INVALID; 517 return 0; 518 } 519 520 void 521 mm_send_keystate(struct ssh *ssh, struct monitor *monitor) 522 { 523 struct sshbuf *m; 524 int r; 525 526 if ((m = sshbuf_new()) == NULL) 527 fatal("%s: sshbuf_new failed", __func__); 528 if ((r = ssh_packet_get_state(ssh, m)) != 0) 529 fatal("%s: get_state failed: %s", 530 __func__, ssh_err(r)); 531 mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m); 532 debug3("%s: Finished sending state", __func__); 533 sshbuf_free(m); 534 } 535 536 int 537 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen) 538 { 539 struct sshbuf *m; 540 char *p, *msg; 541 u_int success = 0; 542 int tmp1 = -1, tmp2 = -1, r; 543 544 /* Kludge: ensure there are fds free to receive the pty/tty */ 545 if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 || 546 (tmp2 = dup(pmonitor->m_recvfd)) == -1) { 547 error("%s: cannot allocate fds for pty", __func__); 548 if (tmp1 > 0) 549 close(tmp1); 550 if (tmp2 > 0) 551 close(tmp2); 552 return 0; 553 } 554 close(tmp1); 555 close(tmp2); 556 557 if ((m = sshbuf_new()) == NULL) 558 fatal("%s: sshbuf_new failed", __func__); 559 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, m); 560 561 debug3("%s: waiting for MONITOR_ANS_PTY", __func__); 562 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, m); 563 564 if ((r = sshbuf_get_u32(m, &success)) != 0) 565 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 566 if (success == 0) { 567 debug3("%s: pty alloc failed", __func__); 568 sshbuf_free(m); 569 return (0); 570 } 571 if ((r = sshbuf_get_cstring(m, &p, NULL)) != 0 || 572 (r = sshbuf_get_cstring(m, &msg, NULL)) != 0) 573 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 574 sshbuf_free(m); 575 576 strlcpy(namebuf, p, namebuflen); /* Possible truncation */ 577 free(p); 578 579 if ((r = sshbuf_put(loginmsg, msg, strlen(msg))) != 0) 580 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 581 free(msg); 582 583 if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 || 584 (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1) 585 fatal("%s: receive fds failed", __func__); 586 587 /* Success */ 588 return (1); 589 } 590 591 void 592 mm_session_pty_cleanup2(Session *s) 593 { 594 struct sshbuf *m; 595 int r; 596 597 if (s->ttyfd == -1) 598 return; 599 if ((m = sshbuf_new()) == NULL) 600 fatal("%s: sshbuf_new failed", __func__); 601 if ((r = sshbuf_put_cstring(m, s->tty)) != 0) 602 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 603 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, m); 604 sshbuf_free(m); 605 606 /* closed dup'ed master */ 607 if (s->ptymaster != -1 && close(s->ptymaster) < 0) 608 error("close(s->ptymaster/%d): %s", 609 s->ptymaster, strerror(errno)); 610 611 /* unlink pty from session */ 612 s->ttyfd = -1; 613 } 614 615 #ifdef USE_PAM 616 void 617 mm_start_pam(struct ssh *ssh) 618 { 619 struct sshbuf *m; 620 621 debug3("%s entering", __func__); 622 if (!options.use_pam) 623 fatal("UsePAM=no, but ended up in %s anyway", __func__); 624 625 if ((m = sshbuf_new()) == NULL) 626 fatal("%s: sshbuf_new failed", __func__); 627 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, m); 628 629 sshbuf_free(m); 630 } 631 632 u_int 633 mm_do_pam_account(void) 634 { 635 struct sshbuf *m; 636 int r; 637 u_int ret; 638 size_t len; 639 char *msg; 640 641 debug3("%s entering", __func__); 642 if (!options.use_pam) 643 fatal("UsePAM=no, but ended up in %s anyway", __func__); 644 645 if ((m = sshbuf_new()) == NULL) 646 fatal("%s: sshbuf_new failed", __func__); 647 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, m); 648 649 mm_request_receive_expect(pmonitor->m_recvfd, 650 MONITOR_ANS_PAM_ACCOUNT, m); 651 if ((r = sshbuf_get_u32(m, &ret)) != 0 || 652 (r = sshbuf_get_cstring(m, &msg, &len)) != 0) 653 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 654 sshbuf_put_cstring(loginmsg, msg); 655 free(msg); 656 657 sshbuf_free(m); 658 659 debug3("%s returning %d", __func__, ret); 660 661 return (ret); 662 } 663 664 void * 665 mm_sshpam_init_ctx(Authctxt *authctxt) 666 { 667 struct sshbuf *m; 668 u_int success; 669 int r; 670 671 debug3("%s", __func__); 672 if ((m = sshbuf_new()) == NULL) 673 fatal("%s: sshbuf_new failed", __func__); 674 sshbuf_put_cstring(m, authctxt->user); 675 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, m); 676 debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__); 677 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_INIT_CTX, m); 678 if ((r = sshbuf_get_u32(m, &success)) != 0) 679 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 680 if (success == 0) { 681 debug3("%s: pam_init_ctx failed", __func__); 682 sshbuf_free(m); 683 return (NULL); 684 } 685 sshbuf_free(m); 686 return (authctxt); 687 } 688 689 int 690 mm_sshpam_query(void *ctx, char **name, char **info, 691 u_int *num, char ***prompts, u_int **echo_on) 692 { 693 struct sshbuf *m; 694 u_int i, ret; 695 int r; 696 697 debug3("%s", __func__); 698 if ((m = sshbuf_new()) == NULL) 699 fatal("%s: sshbuf_new failed", __func__); 700 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_QUERY, m); 701 debug3("%s: waiting for MONITOR_ANS_PAM_QUERY", __func__); 702 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_QUERY, m); 703 if ((r = sshbuf_get_u32(m, &ret)) != 0) 704 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 705 debug3("%s: pam_query returned %d", __func__, ret); 706 if ((r = sshbuf_get_cstring(m, name, NULL)) != 0 || 707 (r = sshbuf_get_cstring(m, info, NULL)) != 0 || 708 (r = sshbuf_get_u32(m, num)) != 0) 709 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 710 if (*num > PAM_MAX_NUM_MSG) 711 fatal("%s: received %u PAM messages, expected <= %u", 712 __func__, *num, PAM_MAX_NUM_MSG); 713 *prompts = xcalloc((*num + 1), sizeof(char *)); 714 *echo_on = xcalloc((*num + 1), sizeof(u_int)); 715 for (i = 0; i < *num; ++i) { 716 if ((r = sshbuf_get_cstring(m, &(*prompts)[i], NULL)) != 0 || 717 (r = sshbuf_get_u32(m, (echo_on)[i])) != 0) 718 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 719 } 720 sshbuf_free(m); 721 return (ret); 722 } 723 724 int 725 mm_sshpam_respond(void *ctx, u_int num, char **resp) 726 { 727 struct sshbuf *m; 728 int r; 729 u_int i; 730 u_int ret; 731 732 debug3("%s", __func__); 733 if ((m = sshbuf_new()) == NULL) 734 fatal("%s: sshbuf_new failed", __func__); 735 sshbuf_put_u32(m, num); 736 for (i = 0; i < num; ++i) 737 sshbuf_put_cstring(m, resp[i]); 738 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, m); 739 debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__); 740 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_RESPOND, m); 741 if ((r = sshbuf_get_u32(m, &ret)) != 0) 742 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 743 debug3("%s: pam_respond returned %d", __func__, ret); 744 sshbuf_free(m); 745 return (ret); 746 } 747 748 void 749 mm_sshpam_free_ctx(void *ctxtp) 750 { 751 struct sshbuf *m; 752 753 debug3("%s", __func__); 754 if ((m = sshbuf_new()) == NULL) 755 fatal("%s: sshbuf_new failed", __func__); 756 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_FREE_CTX, m); 757 debug3("%s: waiting for MONITOR_ANS_PAM_FREE_CTX", __func__); 758 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_FREE_CTX, m); 759 sshbuf_free(m); 760 } 761 #endif /* USE_PAM */ 762 763 /* Request process termination */ 764 765 void 766 mm_terminate(void) 767 { 768 struct sshbuf *m; 769 770 if ((m = sshbuf_new()) == NULL) 771 fatal("%s: sshbuf_new failed", __func__); 772 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, m); 773 sshbuf_free(m); 774 } 775 776 #if defined(BSD_AUTH) || defined(SKEY) 777 static void 778 mm_chall_setup(char **name, char **infotxt, u_int *numprompts, 779 char ***prompts, u_int **echo_on) 780 { 781 *name = xstrdup(""); 782 *infotxt = xstrdup(""); 783 *numprompts = 1; 784 *prompts = xcalloc(*numprompts, sizeof(char *)); 785 *echo_on = xcalloc(*numprompts, sizeof(u_int)); 786 (*echo_on)[0] = 0; 787 } 788 789 #ifdef BSD_AUTH 790 int 791 mm_bsdauth_query(void *ctx, char **name, char **infotxt, 792 u_int *numprompts, char ***prompts, u_int **echo_on) 793 { 794 struct sshbuf *m; 795 u_int success; 796 char *challenge; 797 int r; 798 799 debug3("%s: entering", __func__); 800 801 if ((m = sshbuf_new()) == NULL) 802 fatal("%s: sshbuf_new failed", __func__); 803 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, m); 804 805 mm_request_receive_expect(pmonitor->m_recvfd, 806 MONITOR_ANS_BSDAUTHQUERY, m); 807 if ((r = sshbuf_get_u32(m, &success)) != 0) 808 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 809 if (success == 0) { 810 debug3("%s: no challenge", __func__); 811 sshbuf_free(m); 812 return (-1); 813 } 814 815 /* Get the challenge, and format the response */ 816 if ((r = sshbuf_get_cstring(m, &challenge, NULL)) != 0) 817 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 818 sshbuf_free(m); 819 820 mm_chall_setup(name, infotxt, numprompts, prompts, echo_on); 821 (*prompts)[0] = challenge; 822 823 debug3("%s: received challenge: %s", __func__, challenge); 824 825 return (0); 826 } 827 828 int 829 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses) 830 { 831 struct sshbuf *m; 832 int r, authok; 833 834 debug3("%s: entering", __func__); 835 if (numresponses != 1) 836 return (-1); 837 838 if ((m = sshbuf_new()) == NULL) 839 fatal("%s: sshbuf_new failed", __func__); 840 if ((r = sshbuf_put_cstring(m, responses[0])) != 0) 841 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 842 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, m); 843 844 mm_request_receive_expect(pmonitor->m_recvfd, 845 MONITOR_ANS_BSDAUTHRESPOND, m); 846 847 if ((r = sshbuf_get_u32(m, &authok)) != 0) 848 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 849 sshbuf_free(m); 850 851 return ((authok == 0) ? -1 : 0); 852 } 853 #endif 854 855 #ifdef SKEY 856 int 857 mm_skey_query(void *ctx, char **name, char **infotxt, 858 u_int *numprompts, char ***prompts, u_int **echo_on) 859 { 860 struct sshbuf m; 861 u_int success; 862 char *challenge; 863 864 debug3("%s: entering", __func__); 865 866 sshbuf_new(&m); 867 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYQUERY, &m); 868 869 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SKEYQUERY, 870 &m); 871 success = sshbuf_get_int(&m); 872 if (success == 0) { 873 debug3("%s: no challenge", __func__); 874 sshbuf_free(&m); 875 return (-1); 876 } 877 878 /* Get the challenge, and format the response */ 879 challenge = sshbuf_get_string(&m, NULL); 880 sshbuf_free(&m); 881 882 debug3("%s: received challenge: %s", __func__, challenge); 883 884 mm_chall_setup(name, infotxt, numprompts, prompts, echo_on); 885 886 xasprintf(*prompts, "%s%s", challenge, SKEY_PROMPT); 887 free(challenge); 888 889 return (0); 890 } 891 892 int 893 mm_skey_respond(void *ctx, u_int numresponses, char **responses) 894 { 895 struct sshbuf m; 896 int authok; 897 898 debug3("%s: entering", __func__); 899 if (numresponses != 1) 900 return (-1); 901 902 sshbuf_new(&m); 903 sshbuf_put_cstring(&m, responses[0]); 904 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYRESPOND, &m); 905 906 mm_request_receive_expect(pmonitor->m_recvfd, 907 MONITOR_ANS_SKEYRESPOND, &m); 908 909 authok = sshbuf_get_int(&m); 910 sshbuf_free(&m); 911 912 return ((authok == 0) ? -1 : 0); 913 } 914 #endif /* SKEY */ 915 #endif /* BSDAUTH || SKEY */ 916 917 #ifdef GSSAPI 918 OM_uint32 919 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid) 920 { 921 struct sshbuf *m; 922 OM_uint32 major; 923 int r; 924 925 /* Client doesn't get to see the context */ 926 *ctx = NULL; 927 928 if ((m = sshbuf_new()) == NULL) 929 fatal("%s: sshbuf_new failed", __func__); 930 if ((r = sshbuf_put_string(m, goid->elements, goid->length)) != 0) 931 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 932 933 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, m); 934 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, m); 935 936 if ((r = sshbuf_get_u32(m, &major)) != 0) 937 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 938 939 sshbuf_free(m); 940 return (major); 941 } 942 943 OM_uint32 944 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in, 945 gss_buffer_desc *out, OM_uint32 *flagsp) 946 { 947 struct sshbuf *m; 948 OM_uint32 major; 949 u_int flags; 950 int r; 951 952 if ((m = sshbuf_new()) == NULL) 953 fatal("%s: sshbuf_new failed", __func__); 954 if ((r = sshbuf_put_string(m, in->value, in->length)) != 0) 955 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 956 957 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, m); 958 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, m); 959 960 if ((r = sshbuf_get_u32(m, &major)) != 0 || 961 (r = ssh_gssapi_get_buffer_desc(m, out)) != 0) 962 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 963 if (flagsp != NULL) { 964 if ((r = sshbuf_get_u32(m, &flags)) != 0) 965 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 966 *flagsp = flags; 967 } 968 969 sshbuf_free(m); 970 971 return (major); 972 } 973 974 OM_uint32 975 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) 976 { 977 struct sshbuf *m; 978 OM_uint32 major; 979 int r; 980 981 if ((m = sshbuf_new()) == NULL) 982 fatal("%s: sshbuf_new failed", __func__); 983 if ((r = sshbuf_put_string(m, gssbuf->value, gssbuf->length)) != 0 || 984 (r = sshbuf_put_string(m, gssmic->value, gssmic->length)) != 0) 985 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 986 987 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, m); 988 mm_request_receive_expect(pmonitor->m_recvfd, 989 MONITOR_ANS_GSSCHECKMIC, m); 990 991 if ((r = sshbuf_get_u32(m, &major)) != 0) 992 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 993 sshbuf_free(m); 994 return(major); 995 } 996 997 int 998 mm_ssh_gssapi_userok(char *user) 999 { 1000 struct sshbuf *m; 1001 int r; 1002 u_int authenticated = 0; 1003 1004 if ((m = sshbuf_new()) == NULL) 1005 fatal("%s: sshbuf_new failed", __func__); 1006 1007 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, m); 1008 mm_request_receive_expect(pmonitor->m_recvfd, 1009 MONITOR_ANS_GSSUSEROK, m); 1010 1011 if ((r = sshbuf_get_u32(m, &authenticated)) != 0) 1012 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1013 1014 sshbuf_free(m); 1015 debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not "); 1016 return (authenticated); 1017 } 1018 #endif /* GSSAPI */ 1019 1020 #ifdef KRB5 1021 int 1022 mm_auth_krb5(void *ctx, void *argp, char **userp, void *resp) 1023 { 1024 krb5_data *tkt, *reply; 1025 struct sshbuf *m; 1026 u_int success; 1027 int r; 1028 1029 debug3("%s entering", __func__); 1030 tkt = (krb5_data *) argp; 1031 reply = (krb5_data *) resp; 1032 1033 if ((m = sshbuf_new()) == NULL) 1034 fatal("%s: sshbuf_new failed", __func__); 1035 sshbuf_put_string(m, tkt->data, tkt->length); 1036 1037 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KRB5, m); 1038 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KRB5, m); 1039 1040 if ((r = sshbuf_get_u32(m, &success)) != 0) 1041 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1042 if (success) { 1043 size_t len; 1044 u_char *data; 1045 1046 if ((r = sshbuf_get_cstring(m, userp, NULL)) != 0 || 1047 (r = sshbuf_get_string(m, &data, &len)) != 0) 1048 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1049 reply->data = data; 1050 reply->length = len; 1051 } else { 1052 memset(reply, 0, sizeof(*reply)); 1053 *userp = NULL; 1054 } 1055 1056 sshbuf_free(m); 1057 return (success); 1058 } 1059 #endif 1060