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 struct passwd * 251 mm_getpwnamallow(const char *username) 252 { 253 struct ssh *ssh = active_state; /* XXX */ 254 struct sshbuf *m; 255 struct passwd *pw; 256 size_t len; 257 u_int i; 258 ServerOptions *newopts; 259 int r; 260 u_char ok; 261 const u_char *p; 262 263 debug3("%s entering", __func__); 264 265 if ((m = sshbuf_new()) == NULL) 266 fatal("%s: sshbuf_new failed", __func__); 267 if ((r = sshbuf_put_cstring(m, username)) != 0) 268 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 269 270 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, m); 271 272 debug3("%s: waiting for MONITOR_ANS_PWNAM", __func__); 273 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, m); 274 275 if ((r = sshbuf_get_u8(m, &ok)) != 0) 276 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 277 if (ok == 0) { 278 pw = NULL; 279 goto out; 280 } 281 282 /* XXX don't like passing struct passwd like this */ 283 pw = xcalloc(sizeof(*pw), 1); 284 if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0) 285 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 286 if (len != sizeof(*pw)) 287 fatal("%s: struct passwd size mismatch", __func__); 288 memcpy(pw, p, sizeof(*pw)); 289 290 if ((r = sshbuf_get_cstring(m, &pw->pw_name, NULL)) != 0 || 291 (r = sshbuf_get_cstring(m, &pw->pw_passwd, NULL)) != 0 || 292 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS 293 (r = sshbuf_get_cstring(m, &pw->pw_gecos, NULL)) != 0 || 294 #endif 295 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS 296 (r = sshbuf_get_cstring(m, &pw->pw_class, NULL)) != 0 || 297 #endif 298 (r = sshbuf_get_cstring(m, &pw->pw_dir, NULL)) != 0 || 299 (r = sshbuf_get_cstring(m, &pw->pw_shell, NULL)) != 0) 300 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 301 302 out: 303 /* copy options block as a Match directive may have changed some */ 304 if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0) 305 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 306 if (len != sizeof(*newopts)) 307 fatal("%s: option block size mismatch", __func__); 308 newopts = xcalloc(sizeof(*newopts), 1); 309 memcpy(newopts, p, sizeof(*newopts)); 310 311 #define M_CP_STROPT(x) do { \ 312 if (newopts->x != NULL) { \ 313 if ((r = sshbuf_get_cstring(m, \ 314 &newopts->x, NULL)) != 0) \ 315 fatal("%s: buffer error: %s", \ 316 __func__, ssh_err(r)); \ 317 } \ 318 } while (0) 319 #define M_CP_STRARRAYOPT(x, nx) do { \ 320 newopts->x = newopts->nx == 0 ? \ 321 NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \ 322 for (i = 0; i < newopts->nx; i++) { \ 323 if ((r = sshbuf_get_cstring(m, \ 324 &newopts->x[i], NULL)) != 0) \ 325 fatal("%s: buffer error: %s", \ 326 __func__, ssh_err(r)); \ 327 } \ 328 } while (0) 329 /* See comment in servconf.h */ 330 COPY_MATCH_STRING_OPTS(); 331 #undef M_CP_STROPT 332 #undef M_CP_STRARRAYOPT 333 334 copy_set_server_options(&options, newopts, 1); 335 log_change_level(options.log_level); 336 process_permitopen(ssh, &options); 337 free(newopts); 338 339 sshbuf_free(m); 340 341 return (pw); 342 } 343 344 char * 345 mm_auth2_read_banner(void) 346 { 347 struct sshbuf *m; 348 char *banner; 349 int r; 350 351 debug3("%s entering", __func__); 352 353 if ((m = sshbuf_new()) == NULL) 354 fatal("%s: sshbuf_new failed", __func__); 355 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, m); 356 sshbuf_reset(m); 357 358 mm_request_receive_expect(pmonitor->m_recvfd, 359 MONITOR_ANS_AUTH2_READ_BANNER, m); 360 if ((r = sshbuf_get_cstring(m, &banner, NULL)) != 0) 361 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 362 sshbuf_free(m); 363 364 /* treat empty banner as missing banner */ 365 if (strlen(banner) == 0) { 366 free(banner); 367 banner = NULL; 368 } 369 return (banner); 370 } 371 372 /* Inform the privileged process about service and style */ 373 374 void 375 mm_inform_authserv(char *service, char *style) 376 { 377 struct sshbuf *m; 378 int r; 379 380 debug3("%s entering", __func__); 381 382 if ((m = sshbuf_new()) == NULL) 383 fatal("%s: sshbuf_new failed", __func__); 384 if ((r = sshbuf_put_cstring(m, service)) != 0 || 385 (r = sshbuf_put_cstring(m, style ? style : "")) != 0) 386 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 387 388 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, m); 389 390 sshbuf_free(m); 391 } 392 393 /* Do the password authentication */ 394 int 395 mm_auth_password(struct ssh *ssh, char *password) 396 { 397 struct sshbuf *m; 398 int r, authenticated = 0; 399 #ifdef USE_PAM 400 u_int maxtries = 0; 401 #endif 402 403 debug3("%s entering", __func__); 404 405 if ((m = sshbuf_new()) == NULL) 406 fatal("%s: sshbuf_new failed", __func__); 407 if ((r = sshbuf_put_cstring(m, password)) != 0) 408 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 409 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, m); 410 411 debug3("%s: waiting for MONITOR_ANS_AUTHPASSWORD", __func__); 412 mm_request_receive_expect(pmonitor->m_recvfd, 413 MONITOR_ANS_AUTHPASSWORD, m); 414 415 if ((r = sshbuf_get_u32(m, &authenticated)) != 0) 416 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 417 #ifdef USE_PAM 418 if ((r = sshbuf_get_u32(m, &maxtries)) != 0) 419 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 420 if (maxtries > INT_MAX) 421 fatal("%s: bad maxtries %u", __func__, maxtries); 422 sshpam_set_maxtries_reached(maxtries); 423 #endif 424 425 sshbuf_free(m); 426 427 debug3("%s: user %sauthenticated", 428 __func__, authenticated ? "" : "not "); 429 return (authenticated); 430 } 431 432 int 433 mm_user_key_allowed(struct ssh *ssh, struct passwd *pw, struct sshkey *key, 434 int pubkey_auth_attempt, struct sshauthopt **authoptp) 435 { 436 return (mm_key_allowed(MM_USERKEY, NULL, NULL, key, 437 pubkey_auth_attempt, authoptp)); 438 } 439 440 int 441 mm_hostbased_key_allowed(struct passwd *pw, const char *user, const char *host, 442 struct sshkey *key) 443 { 444 return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0, NULL)); 445 } 446 447 int 448 mm_key_allowed(enum mm_keytype type, const char *user, const char *host, 449 struct sshkey *key, int pubkey_auth_attempt, struct sshauthopt **authoptp) 450 { 451 struct sshbuf *m; 452 int r, allowed = 0; 453 struct sshauthopt *opts = NULL; 454 455 debug3("%s entering", __func__); 456 457 if (authoptp != NULL) 458 *authoptp = NULL; 459 460 if ((m = sshbuf_new()) == NULL) 461 fatal("%s: sshbuf_new failed", __func__); 462 if ((r = sshbuf_put_u32(m, type)) != 0 || 463 (r = sshbuf_put_cstring(m, user ? user : "")) != 0 || 464 (r = sshbuf_put_cstring(m, host ? host : "")) != 0 || 465 (r = sshkey_puts(key, m)) != 0 || 466 (r = sshbuf_put_u32(m, pubkey_auth_attempt)) != 0) 467 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 468 469 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, m); 470 471 debug3("%s: waiting for MONITOR_ANS_KEYALLOWED", __func__); 472 mm_request_receive_expect(pmonitor->m_recvfd, 473 MONITOR_ANS_KEYALLOWED, m); 474 475 if ((r = sshbuf_get_u32(m, &allowed)) != 0) 476 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 477 if (allowed && type == MM_USERKEY) { 478 if ((r = sshauthopt_deserialise(m, &opts)) != 0) 479 fatal("%s: sshauthopt_deserialise: %s", 480 __func__, ssh_err(r)); 481 } 482 sshbuf_free(m); 483 484 if (authoptp != NULL) { 485 *authoptp = opts; 486 opts = NULL; 487 } 488 sshauthopt_free(opts); 489 490 return allowed; 491 } 492 493 /* 494 * This key verify needs to send the key type along, because the 495 * privileged parent makes the decision if the key is allowed 496 * for authentication. 497 */ 498 499 int 500 mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen, 501 const u_char *data, size_t datalen, const char *sigalg, u_int compat) 502 { 503 struct sshbuf *m; 504 u_int encoded_ret = 0; 505 int r; 506 507 debug3("%s entering", __func__); 508 509 510 if ((m = sshbuf_new()) == NULL) 511 fatal("%s: sshbuf_new failed", __func__); 512 if ((r = sshkey_puts(key, m)) != 0 || 513 (r = sshbuf_put_string(m, sig, siglen)) != 0 || 514 (r = sshbuf_put_string(m, data, datalen)) != 0 || 515 (r = sshbuf_put_cstring(m, sigalg == NULL ? "" : sigalg)) != 0) 516 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 517 518 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, m); 519 520 debug3("%s: waiting for MONITOR_ANS_KEYVERIFY", __func__); 521 mm_request_receive_expect(pmonitor->m_recvfd, 522 MONITOR_ANS_KEYVERIFY, m); 523 524 if ((r = sshbuf_get_u32(m, &encoded_ret)) != 0) 525 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 526 527 sshbuf_free(m); 528 529 if (encoded_ret != 0) 530 return SSH_ERR_SIGNATURE_INVALID; 531 return 0; 532 } 533 534 void 535 mm_send_keystate(struct monitor *monitor) 536 { 537 struct ssh *ssh = active_state; /* XXX */ 538 struct sshbuf *m; 539 int r; 540 541 if ((m = sshbuf_new()) == NULL) 542 fatal("%s: sshbuf_new failed", __func__); 543 if ((r = ssh_packet_get_state(ssh, m)) != 0) 544 fatal("%s: get_state failed: %s", 545 __func__, ssh_err(r)); 546 mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m); 547 debug3("%s: Finished sending state", __func__); 548 sshbuf_free(m); 549 } 550 551 int 552 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen) 553 { 554 struct sshbuf *m; 555 char *p, *msg; 556 int success = 0, tmp1 = -1, tmp2 = -1, r; 557 558 /* Kludge: ensure there are fds free to receive the pty/tty */ 559 if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 || 560 (tmp2 = dup(pmonitor->m_recvfd)) == -1) { 561 error("%s: cannot allocate fds for pty", __func__); 562 if (tmp1 > 0) 563 close(tmp1); 564 if (tmp2 > 0) 565 close(tmp2); 566 return 0; 567 } 568 close(tmp1); 569 close(tmp2); 570 571 if ((m = sshbuf_new()) == NULL) 572 fatal("%s: sshbuf_new failed", __func__); 573 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, m); 574 575 debug3("%s: waiting for MONITOR_ANS_PTY", __func__); 576 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, m); 577 578 if ((r = sshbuf_get_u32(m, &success)) != 0) 579 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 580 if (success == 0) { 581 debug3("%s: pty alloc failed", __func__); 582 sshbuf_free(m); 583 return (0); 584 } 585 if ((r = sshbuf_get_cstring(m, &p, NULL)) != 0 || 586 (r = sshbuf_get_cstring(m, &msg, NULL)) != 0) 587 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 588 sshbuf_free(m); 589 590 strlcpy(namebuf, p, namebuflen); /* Possible truncation */ 591 free(p); 592 593 if ((r = sshbuf_put(loginmsg, msg, strlen(msg))) != 0) 594 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 595 free(msg); 596 597 if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 || 598 (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1) 599 fatal("%s: receive fds failed", __func__); 600 601 /* Success */ 602 return (1); 603 } 604 605 void 606 mm_session_pty_cleanup2(Session *s) 607 { 608 struct sshbuf *m; 609 int r; 610 611 if (s->ttyfd == -1) 612 return; 613 if ((m = sshbuf_new()) == NULL) 614 fatal("%s: sshbuf_new failed", __func__); 615 if ((r = sshbuf_put_cstring(m, s->tty)) != 0) 616 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 617 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, m); 618 sshbuf_free(m); 619 620 /* closed dup'ed master */ 621 if (s->ptymaster != -1 && close(s->ptymaster) < 0) 622 error("close(s->ptymaster/%d): %s", 623 s->ptymaster, strerror(errno)); 624 625 /* unlink pty from session */ 626 s->ttyfd = -1; 627 } 628 629 #ifdef USE_PAM 630 void 631 mm_start_pam(Authctxt *authctxt) 632 { 633 struct sshbuf *m; 634 635 debug3("%s entering", __func__); 636 if (!options.use_pam) 637 fatal("UsePAM=no, but ended up in %s anyway", __func__); 638 if ((m = sshbuf_new()) == NULL) 639 fatal("%s: sshbuf_new failed", __func__); 640 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, m); 641 642 sshbuf_free(m); 643 } 644 645 u_int 646 mm_do_pam_account(void) 647 { 648 struct sshbuf *m; 649 u_int ret; 650 char *msg; 651 size_t msglen; 652 int r; 653 654 debug3("%s entering", __func__); 655 if (!options.use_pam) 656 fatal("UsePAM=no, but ended up in %s anyway", __func__); 657 658 if ((m = sshbuf_new()) == NULL) 659 fatal("%s: sshbuf_new failed", __func__); 660 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, m); 661 662 mm_request_receive_expect(pmonitor->m_recvfd, 663 MONITOR_ANS_PAM_ACCOUNT, m); 664 if ((r = sshbuf_get_u32(m, &ret)) != 0 || 665 (r = sshbuf_get_cstring(m, &msg, &msglen)) != 0 || 666 (r = sshbuf_put(loginmsg, msg, msglen)) != 0) 667 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 668 669 free(msg); 670 sshbuf_free(m); 671 672 debug3("%s returning %d", __func__, ret); 673 674 return (ret); 675 } 676 677 void * 678 mm_sshpam_init_ctx(Authctxt *authctxt) 679 { 680 struct sshbuf *m; 681 int r, success; 682 683 debug3("%s", __func__); 684 if ((m = sshbuf_new()) == NULL) 685 fatal("%s: sshbuf_new failed", __func__); 686 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, m); 687 debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__); 688 mm_request_receive_expect(pmonitor->m_recvfd, 689 MONITOR_ANS_PAM_INIT_CTX, m); 690 if ((r = sshbuf_get_u32(m, &success)) != 0) 691 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 692 if (success == 0) { 693 debug3("%s: pam_init_ctx failed", __func__); 694 sshbuf_free(m); 695 return (NULL); 696 } 697 sshbuf_free(m); 698 return (authctxt); 699 } 700 701 int 702 mm_sshpam_query(void *ctx, char **name, char **info, 703 u_int *num, char ***prompts, u_int **echo_on) 704 { 705 struct sshbuf *m; 706 u_int i, n; 707 int r, ret; 708 709 debug3("%s", __func__); 710 if ((m = sshbuf_new()) == NULL) 711 fatal("%s: sshbuf_new failed", __func__); 712 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_QUERY, m); 713 debug3("%s: waiting for MONITOR_ANS_PAM_QUERY", __func__); 714 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_QUERY, m); 715 if ((r = sshbuf_get_u32(m, &ret)) != 0 || 716 (r = sshbuf_get_cstring(m, name, NULL)) != 0 || 717 (r = sshbuf_get_cstring(m, info, NULL)) != 0 || 718 (r = sshbuf_get_u32(m, &n)) != 0 || 719 (r = sshbuf_get_u32(m, num)) != 0) 720 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 721 debug3("%s: pam_query returned %d", __func__, ret); 722 sshpam_set_maxtries_reached(n); 723 if (*num > PAM_MAX_NUM_MSG) 724 fatal("%s: received %u PAM messages, expected <= %u", 725 __func__, *num, PAM_MAX_NUM_MSG); 726 *prompts = xcalloc((*num + 1), sizeof(char *)); 727 *echo_on = xcalloc((*num + 1), sizeof(u_int)); 728 for (i = 0; i < *num; ++i) { 729 if ((r = sshbuf_get_cstring(m, &((*prompts)[i]), NULL)) != 0 || 730 (r = sshbuf_get_u32(m, &((*echo_on)[i]))) != 0) 731 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 732 } 733 sshbuf_free(m); 734 return (ret); 735 } 736 737 int 738 mm_sshpam_respond(void *ctx, u_int num, char **resp) 739 { 740 struct sshbuf *m; 741 u_int n, i; 742 int r, ret; 743 744 debug3("%s", __func__); 745 if ((m = sshbuf_new()) == NULL) 746 fatal("%s: sshbuf_new failed", __func__); 747 if ((r = sshbuf_put_u32(m, num)) != 0) 748 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 749 for (i = 0; i < num; ++i) { 750 if ((r = sshbuf_put_cstring(m, resp[i])) != 0) 751 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 752 } 753 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, m); 754 debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__); 755 mm_request_receive_expect(pmonitor->m_recvfd, 756 MONITOR_ANS_PAM_RESPOND, m); 757 if ((r = sshbuf_get_u32(m, &n)) != 0) 758 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 759 ret = (int)n; /* XXX */ 760 debug3("%s: pam_respond returned %d", __func__, ret); 761 sshbuf_free(m); 762 return (ret); 763 } 764 765 void 766 mm_sshpam_free_ctx(void *ctxtp) 767 { 768 struct sshbuf *m; 769 770 debug3("%s", __func__); 771 if ((m = sshbuf_new()) == NULL) 772 fatal("%s: sshbuf_new failed", __func__); 773 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_FREE_CTX, m); 774 debug3("%s: waiting for MONITOR_ANS_PAM_FREE_CTX", __func__); 775 mm_request_receive_expect(pmonitor->m_recvfd, 776 MONITOR_ANS_PAM_FREE_CTX, m); 777 sshbuf_free(m); 778 } 779 #endif /* USE_PAM */ 780 781 /* Request process termination */ 782 783 void 784 mm_terminate(void) 785 { 786 struct sshbuf *m; 787 788 if ((m = sshbuf_new()) == NULL) 789 fatal("%s: sshbuf_new failed", __func__); 790 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, m); 791 sshbuf_free(m); 792 } 793 794 static void 795 mm_chall_setup(char **name, char **infotxt, u_int *numprompts, 796 char ***prompts, u_int **echo_on) 797 { 798 *name = xstrdup(""); 799 *infotxt = xstrdup(""); 800 *numprompts = 1; 801 *prompts = xcalloc(*numprompts, sizeof(char *)); 802 *echo_on = xcalloc(*numprompts, sizeof(u_int)); 803 (*echo_on)[0] = 0; 804 } 805 806 int 807 mm_bsdauth_query(void *ctx, char **name, char **infotxt, 808 u_int *numprompts, char ***prompts, u_int **echo_on) 809 { 810 struct sshbuf *m; 811 u_int success; 812 char *challenge; 813 int r; 814 815 debug3("%s: entering", __func__); 816 817 if ((m = sshbuf_new()) == NULL) 818 fatal("%s: sshbuf_new failed", __func__); 819 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, m); 820 821 mm_request_receive_expect(pmonitor->m_recvfd, 822 MONITOR_ANS_BSDAUTHQUERY, m); 823 if ((r = sshbuf_get_u32(m, &success)) != 0) 824 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 825 if (success == 0) { 826 debug3("%s: no challenge", __func__); 827 sshbuf_free(m); 828 return (-1); 829 } 830 831 /* Get the challenge, and format the response */ 832 if ((r = sshbuf_get_cstring(m, &challenge, NULL)) != 0) 833 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 834 sshbuf_free(m); 835 836 mm_chall_setup(name, infotxt, numprompts, prompts, echo_on); 837 (*prompts)[0] = challenge; 838 839 debug3("%s: received challenge: %s", __func__, challenge); 840 841 return (0); 842 } 843 844 int 845 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses) 846 { 847 struct sshbuf *m; 848 int r, authok; 849 850 debug3("%s: entering", __func__); 851 if (numresponses != 1) 852 return (-1); 853 854 if ((m = sshbuf_new()) == NULL) 855 fatal("%s: sshbuf_new failed", __func__); 856 if ((r = sshbuf_put_cstring(m, responses[0])) != 0) 857 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 858 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, m); 859 860 mm_request_receive_expect(pmonitor->m_recvfd, 861 MONITOR_ANS_BSDAUTHRESPOND, m); 862 863 if ((r = sshbuf_get_u32(m, &authok)) != 0) 864 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 865 sshbuf_free(m); 866 867 return ((authok == 0) ? -1 : 0); 868 } 869 870 #ifdef SSH_AUDIT_EVENTS 871 void 872 mm_audit_event(ssh_audit_event_t event) 873 { 874 struct sshbuf *m; 875 int r; 876 877 debug3("%s entering", __func__); 878 879 if ((m = sshbuf_new()) == NULL) 880 fatal("%s: sshbuf_new failed", __func__); 881 if ((r = sshbuf_put_u32(m, event)) != 0) 882 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 883 884 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_EVENT, m); 885 sshbuf_free(m); 886 } 887 888 void 889 mm_audit_run_command(const char *command) 890 { 891 struct sshbuf *m; 892 int r; 893 894 debug3("%s entering command %s", __func__, command); 895 896 if ((m = sshbuf_new()) == NULL) 897 fatal("%s: sshbuf_new failed", __func__); 898 if ((r = sshbuf_put_cstring(m, command)) != 0) 899 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 900 901 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_COMMAND, m); 902 sshbuf_free(m); 903 } 904 #endif /* SSH_AUDIT_EVENTS */ 905 906 #ifdef GSSAPI 907 OM_uint32 908 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid) 909 { 910 struct sshbuf *m; 911 OM_uint32 major; 912 int r; 913 914 /* Client doesn't get to see the context */ 915 *ctx = NULL; 916 917 if ((m = sshbuf_new()) == NULL) 918 fatal("%s: sshbuf_new failed", __func__); 919 if ((r = sshbuf_put_string(m, goid->elements, goid->length)) != 0) 920 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 921 922 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, m); 923 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, m); 924 925 if ((r = sshbuf_get_u32(m, &major)) != 0) 926 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 927 928 sshbuf_free(m); 929 return (major); 930 } 931 932 OM_uint32 933 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in, 934 gss_buffer_desc *out, OM_uint32 *flagsp) 935 { 936 struct sshbuf *m; 937 OM_uint32 major; 938 u_int flags; 939 int r; 940 941 if ((m = sshbuf_new()) == NULL) 942 fatal("%s: sshbuf_new failed", __func__); 943 if ((r = sshbuf_put_string(m, in->value, in->length)) != 0) 944 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 945 946 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, m); 947 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, m); 948 949 if ((r = sshbuf_get_u32(m, &major)) != 0 || 950 (r = ssh_gssapi_get_buffer_desc(m, out)) != 0) 951 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 952 if (flagsp != NULL) { 953 if ((r = sshbuf_get_u32(m, &flags)) != 0) 954 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 955 *flagsp = flags; 956 } 957 958 sshbuf_free(m); 959 960 return (major); 961 } 962 963 OM_uint32 964 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) 965 { 966 struct sshbuf *m; 967 OM_uint32 major; 968 int r; 969 970 if ((m = sshbuf_new()) == NULL) 971 fatal("%s: sshbuf_new failed", __func__); 972 if ((r = sshbuf_put_string(m, gssbuf->value, gssbuf->length)) != 0 || 973 (r = sshbuf_put_string(m, gssmic->value, gssmic->length)) != 0) 974 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 975 976 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, m); 977 mm_request_receive_expect(pmonitor->m_recvfd, 978 MONITOR_ANS_GSSCHECKMIC, m); 979 980 if ((r = sshbuf_get_u32(m, &major)) != 0) 981 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 982 sshbuf_free(m); 983 return(major); 984 } 985 986 int 987 mm_ssh_gssapi_userok(char *user) 988 { 989 struct sshbuf *m; 990 int r, authenticated = 0; 991 992 if ((m = sshbuf_new()) == NULL) 993 fatal("%s: sshbuf_new failed", __func__); 994 995 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, m); 996 mm_request_receive_expect(pmonitor->m_recvfd, 997 MONITOR_ANS_GSSUSEROK, m); 998 999 if ((r = sshbuf_get_u32(m, &authenticated)) != 0) 1000 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1001 1002 sshbuf_free(m); 1003 debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not "); 1004 return (authenticated); 1005 } 1006 #endif /* GSSAPI */ 1007