1 /* $OpenBSD: monitor_wrap.c,v 1.112 2019/01/21 09:54:11 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 ((r = sshbuf_get_bignum2(m, &p)) != 0 || 206 (r = sshbuf_get_bignum2(m, &g)) != 0) 207 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 208 209 debug3("%s: remaining %zu", __func__, sshbuf_len(m)); 210 sshbuf_free(m); 211 212 return (dh_new_group(g, p)); 213 } 214 #endif 215 216 int 217 mm_sshkey_sign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp, 218 const u_char *data, size_t datalen, const char *hostkey_alg, u_int compat) 219 { 220 struct kex *kex = *pmonitor->m_pkex; 221 struct sshbuf *m; 222 u_int ndx = kex->host_key_index(key, 0, ssh); 223 int r; 224 225 debug3("%s entering", __func__); 226 227 if ((m = sshbuf_new()) == NULL) 228 fatal("%s: sshbuf_new failed", __func__); 229 if ((r = sshbuf_put_u32(m, ndx)) != 0 || 230 (r = sshbuf_put_string(m, data, datalen)) != 0 || 231 (r = sshbuf_put_cstring(m, hostkey_alg)) != 0 || 232 (r = sshbuf_put_u32(m, compat)) != 0) 233 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 234 235 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, m); 236 237 debug3("%s: waiting for MONITOR_ANS_SIGN", __func__); 238 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, m); 239 if ((r = sshbuf_get_string(m, sigp, lenp)) != 0) 240 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 241 sshbuf_free(m); 242 243 return (0); 244 } 245 246 struct passwd * 247 mm_getpwnamallow(struct ssh *ssh, const char *username) 248 { 249 struct sshbuf *m; 250 struct passwd *pw; 251 size_t len; 252 u_int i; 253 ServerOptions *newopts; 254 int r; 255 u_char ok; 256 const u_char *p; 257 258 debug3("%s entering", __func__); 259 260 if ((m = sshbuf_new()) == NULL) 261 fatal("%s: sshbuf_new failed", __func__); 262 if ((r = sshbuf_put_cstring(m, username)) != 0) 263 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 264 265 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, m); 266 267 debug3("%s: waiting for MONITOR_ANS_PWNAM", __func__); 268 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, m); 269 270 if ((r = sshbuf_get_u8(m, &ok)) != 0) 271 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 272 if (ok == 0) { 273 pw = NULL; 274 goto out; 275 } 276 277 /* XXX don't like passing struct passwd like this */ 278 pw = xcalloc(sizeof(*pw), 1); 279 if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0) 280 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 281 if (len != sizeof(*pw)) 282 fatal("%s: struct passwd size mismatch", __func__); 283 memcpy(pw, p, sizeof(*pw)); 284 285 if ((r = sshbuf_get_cstring(m, &pw->pw_name, NULL)) != 0 || 286 (r = sshbuf_get_cstring(m, &pw->pw_passwd, NULL)) != 0 || 287 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS 288 (r = sshbuf_get_cstring(m, &pw->pw_gecos, NULL)) != 0 || 289 #endif 290 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS 291 (r = sshbuf_get_cstring(m, &pw->pw_class, NULL)) != 0 || 292 #endif 293 (r = sshbuf_get_cstring(m, &pw->pw_dir, NULL)) != 0 || 294 (r = sshbuf_get_cstring(m, &pw->pw_shell, NULL)) != 0) 295 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 296 297 out: 298 /* copy options block as a Match directive may have changed some */ 299 if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0) 300 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 301 if (len != sizeof(*newopts)) 302 fatal("%s: option block size mismatch", __func__); 303 newopts = xcalloc(sizeof(*newopts), 1); 304 memcpy(newopts, p, sizeof(*newopts)); 305 306 #define M_CP_STROPT(x) do { \ 307 if (newopts->x != NULL) { \ 308 if ((r = sshbuf_get_cstring(m, \ 309 &newopts->x, NULL)) != 0) \ 310 fatal("%s: buffer error: %s", \ 311 __func__, ssh_err(r)); \ 312 } \ 313 } while (0) 314 #define M_CP_STRARRAYOPT(x, nx) do { \ 315 newopts->x = newopts->nx == 0 ? \ 316 NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \ 317 for (i = 0; i < newopts->nx; i++) { \ 318 if ((r = sshbuf_get_cstring(m, \ 319 &newopts->x[i], NULL)) != 0) \ 320 fatal("%s: buffer error: %s", \ 321 __func__, ssh_err(r)); \ 322 } \ 323 } while (0) 324 /* See comment in servconf.h */ 325 COPY_MATCH_STRING_OPTS(); 326 #undef M_CP_STROPT 327 #undef M_CP_STRARRAYOPT 328 329 copy_set_server_options(&options, newopts, 1); 330 log_change_level(options.log_level); 331 process_permitopen(ssh, &options); 332 free(newopts); 333 334 sshbuf_free(m); 335 336 return (pw); 337 } 338 339 char * 340 mm_auth2_read_banner(void) 341 { 342 struct sshbuf *m; 343 char *banner; 344 int r; 345 346 debug3("%s entering", __func__); 347 348 if ((m = sshbuf_new()) == NULL) 349 fatal("%s: sshbuf_new failed", __func__); 350 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, m); 351 sshbuf_reset(m); 352 353 mm_request_receive_expect(pmonitor->m_recvfd, 354 MONITOR_ANS_AUTH2_READ_BANNER, m); 355 if ((r = sshbuf_get_cstring(m, &banner, NULL)) != 0) 356 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 357 sshbuf_free(m); 358 359 /* treat empty banner as missing banner */ 360 if (strlen(banner) == 0) { 361 free(banner); 362 banner = NULL; 363 } 364 return (banner); 365 } 366 367 /* Inform the privileged process about service and style */ 368 369 void 370 mm_inform_authserv(char *service, char *style) 371 { 372 struct sshbuf *m; 373 int r; 374 375 debug3("%s entering", __func__); 376 377 if ((m = sshbuf_new()) == NULL) 378 fatal("%s: sshbuf_new failed", __func__); 379 if ((r = sshbuf_put_cstring(m, service)) != 0 || 380 (r = sshbuf_put_cstring(m, style ? style : "")) != 0) 381 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 382 383 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, m); 384 385 sshbuf_free(m); 386 } 387 388 /* Do the password authentication */ 389 int 390 mm_auth_password(struct ssh *ssh, char *password) 391 { 392 struct sshbuf *m; 393 int r, authenticated = 0; 394 #ifdef USE_PAM 395 u_int maxtries = 0; 396 #endif 397 398 debug3("%s entering", __func__); 399 400 if ((m = sshbuf_new()) == NULL) 401 fatal("%s: sshbuf_new failed", __func__); 402 if ((r = sshbuf_put_cstring(m, password)) != 0) 403 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 404 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, m); 405 406 debug3("%s: waiting for MONITOR_ANS_AUTHPASSWORD", __func__); 407 mm_request_receive_expect(pmonitor->m_recvfd, 408 MONITOR_ANS_AUTHPASSWORD, m); 409 410 if ((r = sshbuf_get_u32(m, &authenticated)) != 0) 411 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 412 #ifdef USE_PAM 413 if ((r = sshbuf_get_u32(m, &maxtries)) != 0) 414 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 415 if (maxtries > INT_MAX) 416 fatal("%s: bad maxtries %u", __func__, maxtries); 417 sshpam_set_maxtries_reached(maxtries); 418 #endif 419 420 sshbuf_free(m); 421 422 debug3("%s: user %sauthenticated", 423 __func__, authenticated ? "" : "not "); 424 return (authenticated); 425 } 426 427 int 428 mm_user_key_allowed(struct ssh *ssh, struct passwd *pw, struct sshkey *key, 429 int pubkey_auth_attempt, struct sshauthopt **authoptp) 430 { 431 return (mm_key_allowed(MM_USERKEY, NULL, NULL, key, 432 pubkey_auth_attempt, authoptp)); 433 } 434 435 int 436 mm_hostbased_key_allowed(struct ssh *ssh, struct passwd *pw, 437 const char *user, const char *host, struct sshkey *key) 438 { 439 return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0, NULL)); 440 } 441 442 int 443 mm_key_allowed(enum mm_keytype type, const char *user, const char *host, 444 struct sshkey *key, int pubkey_auth_attempt, struct sshauthopt **authoptp) 445 { 446 struct sshbuf *m; 447 int r, allowed = 0; 448 struct sshauthopt *opts = NULL; 449 450 debug3("%s entering", __func__); 451 452 if (authoptp != NULL) 453 *authoptp = NULL; 454 455 if ((m = sshbuf_new()) == NULL) 456 fatal("%s: sshbuf_new failed", __func__); 457 if ((r = sshbuf_put_u32(m, type)) != 0 || 458 (r = sshbuf_put_cstring(m, user ? user : "")) != 0 || 459 (r = sshbuf_put_cstring(m, host ? host : "")) != 0 || 460 (r = sshkey_puts(key, m)) != 0 || 461 (r = sshbuf_put_u32(m, pubkey_auth_attempt)) != 0) 462 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 463 464 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, m); 465 466 debug3("%s: waiting for MONITOR_ANS_KEYALLOWED", __func__); 467 mm_request_receive_expect(pmonitor->m_recvfd, 468 MONITOR_ANS_KEYALLOWED, m); 469 470 if ((r = sshbuf_get_u32(m, &allowed)) != 0) 471 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 472 if (allowed && type == MM_USERKEY) { 473 if ((r = sshauthopt_deserialise(m, &opts)) != 0) 474 fatal("%s: sshauthopt_deserialise: %s", 475 __func__, ssh_err(r)); 476 } 477 sshbuf_free(m); 478 479 if (authoptp != NULL) { 480 *authoptp = opts; 481 opts = NULL; 482 } 483 sshauthopt_free(opts); 484 485 return allowed; 486 } 487 488 /* 489 * This key verify needs to send the key type along, because the 490 * privileged parent makes the decision if the key is allowed 491 * for authentication. 492 */ 493 494 int 495 mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen, 496 const u_char *data, size_t datalen, const char *sigalg, u_int compat) 497 { 498 struct sshbuf *m; 499 u_int encoded_ret = 0; 500 int r; 501 502 debug3("%s entering", __func__); 503 504 505 if ((m = sshbuf_new()) == NULL) 506 fatal("%s: sshbuf_new failed", __func__); 507 if ((r = sshkey_puts(key, m)) != 0 || 508 (r = sshbuf_put_string(m, sig, siglen)) != 0 || 509 (r = sshbuf_put_string(m, data, datalen)) != 0 || 510 (r = sshbuf_put_cstring(m, sigalg == NULL ? "" : sigalg)) != 0) 511 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 512 513 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, m); 514 515 debug3("%s: waiting for MONITOR_ANS_KEYVERIFY", __func__); 516 mm_request_receive_expect(pmonitor->m_recvfd, 517 MONITOR_ANS_KEYVERIFY, m); 518 519 if ((r = sshbuf_get_u32(m, &encoded_ret)) != 0) 520 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 521 522 sshbuf_free(m); 523 524 if (encoded_ret != 0) 525 return SSH_ERR_SIGNATURE_INVALID; 526 return 0; 527 } 528 529 void 530 mm_send_keystate(struct ssh *ssh, struct monitor *monitor) 531 { 532 struct sshbuf *m; 533 int r; 534 535 if ((m = sshbuf_new()) == NULL) 536 fatal("%s: sshbuf_new failed", __func__); 537 if ((r = ssh_packet_get_state(ssh, m)) != 0) 538 fatal("%s: get_state failed: %s", 539 __func__, ssh_err(r)); 540 mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m); 541 debug3("%s: Finished sending state", __func__); 542 sshbuf_free(m); 543 } 544 545 int 546 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen) 547 { 548 struct sshbuf *m; 549 char *p, *msg; 550 int success = 0, tmp1 = -1, tmp2 = -1, r; 551 552 /* Kludge: ensure there are fds free to receive the pty/tty */ 553 if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 || 554 (tmp2 = dup(pmonitor->m_recvfd)) == -1) { 555 error("%s: cannot allocate fds for pty", __func__); 556 if (tmp1 > 0) 557 close(tmp1); 558 if (tmp2 > 0) 559 close(tmp2); 560 return 0; 561 } 562 close(tmp1); 563 close(tmp2); 564 565 if ((m = sshbuf_new()) == NULL) 566 fatal("%s: sshbuf_new failed", __func__); 567 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, m); 568 569 debug3("%s: waiting for MONITOR_ANS_PTY", __func__); 570 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, m); 571 572 if ((r = sshbuf_get_u32(m, &success)) != 0) 573 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 574 if (success == 0) { 575 debug3("%s: pty alloc failed", __func__); 576 sshbuf_free(m); 577 return (0); 578 } 579 if ((r = sshbuf_get_cstring(m, &p, NULL)) != 0 || 580 (r = sshbuf_get_cstring(m, &msg, NULL)) != 0) 581 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 582 sshbuf_free(m); 583 584 strlcpy(namebuf, p, namebuflen); /* Possible truncation */ 585 free(p); 586 587 if ((r = sshbuf_put(loginmsg, msg, strlen(msg))) != 0) 588 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 589 free(msg); 590 591 if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 || 592 (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1) 593 fatal("%s: receive fds failed", __func__); 594 595 /* Success */ 596 return (1); 597 } 598 599 void 600 mm_session_pty_cleanup2(Session *s) 601 { 602 struct sshbuf *m; 603 int r; 604 605 if (s->ttyfd == -1) 606 return; 607 if ((m = sshbuf_new()) == NULL) 608 fatal("%s: sshbuf_new failed", __func__); 609 if ((r = sshbuf_put_cstring(m, s->tty)) != 0) 610 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 611 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, m); 612 sshbuf_free(m); 613 614 /* closed dup'ed master */ 615 if (s->ptymaster != -1 && close(s->ptymaster) < 0) 616 error("close(s->ptymaster/%d): %s", 617 s->ptymaster, strerror(errno)); 618 619 /* unlink pty from session */ 620 s->ttyfd = -1; 621 } 622 623 #ifdef USE_PAM 624 void 625 mm_start_pam(struct ssh *ssh) 626 { 627 struct sshbuf *m; 628 629 debug3("%s entering", __func__); 630 if (!options.use_pam) 631 fatal("UsePAM=no, but ended up in %s anyway", __func__); 632 if ((m = sshbuf_new()) == NULL) 633 fatal("%s: sshbuf_new failed", __func__); 634 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, m); 635 636 sshbuf_free(m); 637 } 638 639 u_int 640 mm_do_pam_account(void) 641 { 642 struct sshbuf *m; 643 u_int ret; 644 char *msg; 645 size_t msglen; 646 int r; 647 648 debug3("%s entering", __func__); 649 if (!options.use_pam) 650 fatal("UsePAM=no, but ended up in %s anyway", __func__); 651 652 if ((m = sshbuf_new()) == NULL) 653 fatal("%s: sshbuf_new failed", __func__); 654 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, m); 655 656 mm_request_receive_expect(pmonitor->m_recvfd, 657 MONITOR_ANS_PAM_ACCOUNT, m); 658 if ((r = sshbuf_get_u32(m, &ret)) != 0 || 659 (r = sshbuf_get_cstring(m, &msg, &msglen)) != 0 || 660 (r = sshbuf_put(loginmsg, msg, msglen)) != 0) 661 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 662 663 free(msg); 664 sshbuf_free(m); 665 666 debug3("%s returning %d", __func__, ret); 667 668 return (ret); 669 } 670 671 void * 672 mm_sshpam_init_ctx(Authctxt *authctxt) 673 { 674 struct sshbuf *m; 675 int r, success; 676 677 debug3("%s", __func__); 678 if ((m = sshbuf_new()) == NULL) 679 fatal("%s: sshbuf_new failed", __func__); 680 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, m); 681 debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__); 682 mm_request_receive_expect(pmonitor->m_recvfd, 683 MONITOR_ANS_PAM_INIT_CTX, m); 684 if ((r = sshbuf_get_u32(m, &success)) != 0) 685 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 686 if (success == 0) { 687 debug3("%s: pam_init_ctx failed", __func__); 688 sshbuf_free(m); 689 return (NULL); 690 } 691 sshbuf_free(m); 692 return (authctxt); 693 } 694 695 int 696 mm_sshpam_query(void *ctx, char **name, char **info, 697 u_int *num, char ***prompts, u_int **echo_on) 698 { 699 struct sshbuf *m; 700 u_int i, n; 701 int r, ret; 702 703 debug3("%s", __func__); 704 if ((m = sshbuf_new()) == NULL) 705 fatal("%s: sshbuf_new failed", __func__); 706 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_QUERY, m); 707 debug3("%s: waiting for MONITOR_ANS_PAM_QUERY", __func__); 708 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_QUERY, m); 709 if ((r = sshbuf_get_u32(m, &ret)) != 0 || 710 (r = sshbuf_get_cstring(m, name, NULL)) != 0 || 711 (r = sshbuf_get_cstring(m, info, NULL)) != 0 || 712 (r = sshbuf_get_u32(m, &n)) != 0 || 713 (r = sshbuf_get_u32(m, num)) != 0) 714 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 715 debug3("%s: pam_query returned %d", __func__, ret); 716 sshpam_set_maxtries_reached(n); 717 if (*num > PAM_MAX_NUM_MSG) 718 fatal("%s: received %u PAM messages, expected <= %u", 719 __func__, *num, PAM_MAX_NUM_MSG); 720 *prompts = xcalloc((*num + 1), sizeof(char *)); 721 *echo_on = xcalloc((*num + 1), sizeof(u_int)); 722 for (i = 0; i < *num; ++i) { 723 if ((r = sshbuf_get_cstring(m, &((*prompts)[i]), NULL)) != 0 || 724 (r = sshbuf_get_u32(m, &((*echo_on)[i]))) != 0) 725 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 726 } 727 sshbuf_free(m); 728 return (ret); 729 } 730 731 int 732 mm_sshpam_respond(void *ctx, u_int num, char **resp) 733 { 734 struct sshbuf *m; 735 u_int n, i; 736 int r, ret; 737 738 debug3("%s", __func__); 739 if ((m = sshbuf_new()) == NULL) 740 fatal("%s: sshbuf_new failed", __func__); 741 if ((r = sshbuf_put_u32(m, num)) != 0) 742 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 743 for (i = 0; i < num; ++i) { 744 if ((r = sshbuf_put_cstring(m, resp[i])) != 0) 745 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 746 } 747 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, m); 748 debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__); 749 mm_request_receive_expect(pmonitor->m_recvfd, 750 MONITOR_ANS_PAM_RESPOND, m); 751 if ((r = sshbuf_get_u32(m, &n)) != 0) 752 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 753 ret = (int)n; /* XXX */ 754 debug3("%s: pam_respond returned %d", __func__, ret); 755 sshbuf_free(m); 756 return (ret); 757 } 758 759 void 760 mm_sshpam_free_ctx(void *ctxtp) 761 { 762 struct sshbuf *m; 763 764 debug3("%s", __func__); 765 if ((m = sshbuf_new()) == NULL) 766 fatal("%s: sshbuf_new failed", __func__); 767 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_FREE_CTX, m); 768 debug3("%s: waiting for MONITOR_ANS_PAM_FREE_CTX", __func__); 769 mm_request_receive_expect(pmonitor->m_recvfd, 770 MONITOR_ANS_PAM_FREE_CTX, m); 771 sshbuf_free(m); 772 } 773 #endif /* USE_PAM */ 774 775 /* Request process termination */ 776 777 void 778 mm_terminate(void) 779 { 780 struct sshbuf *m; 781 782 if ((m = sshbuf_new()) == NULL) 783 fatal("%s: sshbuf_new failed", __func__); 784 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, m); 785 sshbuf_free(m); 786 } 787 788 static void 789 mm_chall_setup(char **name, char **infotxt, u_int *numprompts, 790 char ***prompts, u_int **echo_on) 791 { 792 *name = xstrdup(""); 793 *infotxt = xstrdup(""); 794 *numprompts = 1; 795 *prompts = xcalloc(*numprompts, sizeof(char *)); 796 *echo_on = xcalloc(*numprompts, sizeof(u_int)); 797 (*echo_on)[0] = 0; 798 } 799 800 int 801 mm_bsdauth_query(void *ctx, char **name, char **infotxt, 802 u_int *numprompts, char ***prompts, u_int **echo_on) 803 { 804 struct sshbuf *m; 805 u_int success; 806 char *challenge; 807 int r; 808 809 debug3("%s: entering", __func__); 810 811 if ((m = sshbuf_new()) == NULL) 812 fatal("%s: sshbuf_new failed", __func__); 813 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, m); 814 815 mm_request_receive_expect(pmonitor->m_recvfd, 816 MONITOR_ANS_BSDAUTHQUERY, m); 817 if ((r = sshbuf_get_u32(m, &success)) != 0) 818 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 819 if (success == 0) { 820 debug3("%s: no challenge", __func__); 821 sshbuf_free(m); 822 return (-1); 823 } 824 825 /* Get the challenge, and format the response */ 826 if ((r = sshbuf_get_cstring(m, &challenge, NULL)) != 0) 827 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 828 sshbuf_free(m); 829 830 mm_chall_setup(name, infotxt, numprompts, prompts, echo_on); 831 (*prompts)[0] = challenge; 832 833 debug3("%s: received challenge: %s", __func__, challenge); 834 835 return (0); 836 } 837 838 int 839 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses) 840 { 841 struct sshbuf *m; 842 int r, authok; 843 844 debug3("%s: entering", __func__); 845 if (numresponses != 1) 846 return (-1); 847 848 if ((m = sshbuf_new()) == NULL) 849 fatal("%s: sshbuf_new failed", __func__); 850 if ((r = sshbuf_put_cstring(m, responses[0])) != 0) 851 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 852 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, m); 853 854 mm_request_receive_expect(pmonitor->m_recvfd, 855 MONITOR_ANS_BSDAUTHRESPOND, m); 856 857 if ((r = sshbuf_get_u32(m, &authok)) != 0) 858 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 859 sshbuf_free(m); 860 861 return ((authok == 0) ? -1 : 0); 862 } 863 864 #ifdef SSH_AUDIT_EVENTS 865 void 866 mm_audit_event(struct ssh *ssh, ssh_audit_event_t event) 867 { 868 struct sshbuf *m; 869 int r; 870 871 debug3("%s entering", __func__); 872 873 if ((m = sshbuf_new()) == NULL) 874 fatal("%s: sshbuf_new failed", __func__); 875 if ((r = sshbuf_put_u32(m, event)) != 0) 876 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 877 878 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_EVENT, m); 879 sshbuf_free(m); 880 } 881 882 void 883 mm_audit_run_command(const char *command) 884 { 885 struct sshbuf *m; 886 int r; 887 888 debug3("%s entering command %s", __func__, command); 889 890 if ((m = sshbuf_new()) == NULL) 891 fatal("%s: sshbuf_new failed", __func__); 892 if ((r = sshbuf_put_cstring(m, command)) != 0) 893 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 894 895 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_COMMAND, m); 896 sshbuf_free(m); 897 } 898 #endif /* SSH_AUDIT_EVENTS */ 899 900 #ifdef GSSAPI 901 OM_uint32 902 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid) 903 { 904 struct sshbuf *m; 905 OM_uint32 major; 906 int r; 907 908 /* Client doesn't get to see the context */ 909 *ctx = NULL; 910 911 if ((m = sshbuf_new()) == NULL) 912 fatal("%s: sshbuf_new failed", __func__); 913 if ((r = sshbuf_put_string(m, goid->elements, goid->length)) != 0) 914 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 915 916 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, m); 917 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, m); 918 919 if ((r = sshbuf_get_u32(m, &major)) != 0) 920 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 921 922 sshbuf_free(m); 923 return (major); 924 } 925 926 OM_uint32 927 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in, 928 gss_buffer_desc *out, OM_uint32 *flagsp) 929 { 930 struct sshbuf *m; 931 OM_uint32 major; 932 u_int flags; 933 int r; 934 935 if ((m = sshbuf_new()) == NULL) 936 fatal("%s: sshbuf_new failed", __func__); 937 if ((r = sshbuf_put_string(m, in->value, in->length)) != 0) 938 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 939 940 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, m); 941 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, m); 942 943 if ((r = sshbuf_get_u32(m, &major)) != 0 || 944 (r = ssh_gssapi_get_buffer_desc(m, out)) != 0) 945 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 946 if (flagsp != NULL) { 947 if ((r = sshbuf_get_u32(m, &flags)) != 0) 948 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 949 *flagsp = flags; 950 } 951 952 sshbuf_free(m); 953 954 return (major); 955 } 956 957 OM_uint32 958 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) 959 { 960 struct sshbuf *m; 961 OM_uint32 major; 962 int r; 963 964 if ((m = sshbuf_new()) == NULL) 965 fatal("%s: sshbuf_new failed", __func__); 966 if ((r = sshbuf_put_string(m, gssbuf->value, gssbuf->length)) != 0 || 967 (r = sshbuf_put_string(m, gssmic->value, gssmic->length)) != 0) 968 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 969 970 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, m); 971 mm_request_receive_expect(pmonitor->m_recvfd, 972 MONITOR_ANS_GSSCHECKMIC, m); 973 974 if ((r = sshbuf_get_u32(m, &major)) != 0) 975 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 976 sshbuf_free(m); 977 return(major); 978 } 979 980 int 981 mm_ssh_gssapi_userok(char *user) 982 { 983 struct sshbuf *m; 984 int r, authenticated = 0; 985 986 if ((m = sshbuf_new()) == NULL) 987 fatal("%s: sshbuf_new failed", __func__); 988 989 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, m); 990 mm_request_receive_expect(pmonitor->m_recvfd, 991 MONITOR_ANS_GSSUSEROK, m); 992 993 if ((r = sshbuf_get_u32(m, &authenticated)) != 0) 994 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 995 996 sshbuf_free(m); 997 debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not "); 998 return (authenticated); 999 } 1000 #endif /* GSSAPI */ 1001