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 <sys/types.h> 29 #include <sys/uio.h> 30 #include <sys/queue.h> 31 32 #include <errno.h> 33 #include <pwd.h> 34 #include <signal.h> 35 #include <stdio.h> 36 #include <string.h> 37 #include <unistd.h> 38 39 #ifdef WITH_OPENSSL 40 #include <openssl/bn.h> 41 #include <openssl/dh.h> 42 #endif 43 44 #include "xmalloc.h" 45 #include "ssh.h" 46 #ifdef WITH_OPENSSL 47 #include "dh.h" 48 #endif 49 #include "sshbuf.h" 50 #include "sshkey.h" 51 #include "cipher.h" 52 #include "kex.h" 53 #include "hostfile.h" 54 #include "auth.h" 55 #include "auth-options.h" 56 #include "packet.h" 57 #include "mac.h" 58 #include "log.h" 59 #include "monitor.h" 60 #ifdef GSSAPI 61 #include "ssh-gss.h" 62 #endif 63 #include "monitor_wrap.h" 64 #include "atomicio.h" 65 #include "monitor_fdpass.h" 66 #include "misc.h" 67 68 #include "channels.h" 69 #include "session.h" 70 #include "servconf.h" 71 72 #include "ssherr.h" 73 74 /* Imports */ 75 extern struct monitor *pmonitor; 76 extern struct sshbuf *loginmsg; 77 extern ServerOptions options; 78 79 void 80 mm_log_handler(LogLevel level, const char *msg, void *ctx) 81 { 82 struct sshbuf *log_msg; 83 struct monitor *mon = (struct monitor *)ctx; 84 int r; 85 size_t len; 86 87 if (mon->m_log_sendfd == -1) 88 fatal("%s: no log channel", __func__); 89 90 if ((log_msg = sshbuf_new()) == NULL) 91 fatal("%s: sshbuf_new failed", __func__); 92 93 if ((r = sshbuf_put_u32(log_msg, 0)) != 0 || /* length; filled below */ 94 (r = sshbuf_put_u32(log_msg, level)) != 0 || 95 (r = sshbuf_put_cstring(log_msg, msg)) != 0) 96 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 97 if ((len = sshbuf_len(log_msg)) < 4 || len > 0xffffffff) 98 fatal("%s: bad length %zu", __func__, len); 99 POKE_U32(sshbuf_mutable_ptr(log_msg), len - 4); 100 if (atomicio(vwrite, mon->m_log_sendfd, 101 sshbuf_mutable_ptr(log_msg), len) != len) 102 fatal("%s: write: %s", __func__, strerror(errno)); 103 sshbuf_free(log_msg); 104 } 105 106 int 107 mm_is_monitor(void) 108 { 109 /* 110 * m_pid is only set in the privileged part, and 111 * points to the unprivileged child. 112 */ 113 return (pmonitor && pmonitor->m_pid > 0); 114 } 115 116 void 117 mm_request_send(int sock, enum monitor_reqtype type, struct sshbuf *m) 118 { 119 size_t mlen = sshbuf_len(m); 120 u_char buf[5]; 121 122 debug3("%s entering: type %d", __func__, type); 123 124 if (mlen >= 0xffffffff) 125 fatal("%s: bad length %zu", __func__, mlen); 126 POKE_U32(buf, mlen + 1); 127 buf[4] = (u_char) type; /* 1st byte of payload is mesg-type */ 128 if (atomicio(vwrite, sock, buf, sizeof(buf)) != sizeof(buf)) 129 fatal("%s: write: %s", __func__, strerror(errno)); 130 if (atomicio(vwrite, sock, sshbuf_mutable_ptr(m), mlen) != mlen) 131 fatal("%s: write: %s", __func__, strerror(errno)); 132 } 133 134 void 135 mm_request_receive(int sock, struct sshbuf *m) 136 { 137 u_char buf[4], *p = NULL; 138 u_int msg_len; 139 int r; 140 141 debug3("%s entering", __func__); 142 143 if (atomicio(read, sock, buf, sizeof(buf)) != sizeof(buf)) { 144 if (errno == EPIPE) 145 cleanup_exit(255); 146 fatal("%s: read: %s", __func__, strerror(errno)); 147 } 148 msg_len = PEEK_U32(buf); 149 if (msg_len > 256 * 1024) 150 fatal("%s: read: bad msg_len %d", __func__, msg_len); 151 sshbuf_reset(m); 152 if ((r = sshbuf_reserve(m, msg_len, &p)) != 0) 153 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 154 if (atomicio(read, sock, p, msg_len) != msg_len) 155 fatal("%s: read: %s", __func__, strerror(errno)); 156 } 157 158 void 159 mm_request_receive_expect(int sock, enum monitor_reqtype type, struct sshbuf *m) 160 { 161 u_char rtype; 162 int r; 163 164 debug3("%s entering: type %d", __func__, type); 165 166 mm_request_receive(sock, m); 167 if ((r = sshbuf_get_u8(m, &rtype)) != 0) 168 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 169 if (rtype != type) 170 fatal("%s: read: rtype %d != type %d", __func__, 171 rtype, type); 172 } 173 174 #ifdef WITH_OPENSSL 175 DH * 176 mm_choose_dh(int min, int nbits, int max) 177 { 178 BIGNUM *p, *g; 179 int r; 180 u_char success = 0; 181 struct sshbuf *m; 182 183 if ((m = sshbuf_new()) == NULL) 184 fatal("%s: sshbuf_new failed", __func__); 185 if ((r = sshbuf_put_u32(m, min)) != 0 || 186 (r = sshbuf_put_u32(m, nbits)) != 0 || 187 (r = sshbuf_put_u32(m, max)) != 0) 188 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 189 190 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_MODULI, m); 191 192 debug3("%s: waiting for MONITOR_ANS_MODULI", __func__); 193 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_MODULI, m); 194 195 if ((r = sshbuf_get_u8(m, &success)) != 0) 196 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 197 if (success == 0) 198 fatal("%s: MONITOR_ANS_MODULI failed", __func__); 199 200 if ((r = sshbuf_get_bignum2(m, &p)) != 0 || 201 (r = sshbuf_get_bignum2(m, &g)) != 0) 202 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 203 204 debug3("%s: remaining %zu", __func__, sshbuf_len(m)); 205 sshbuf_free(m); 206 207 return (dh_new_group(g, p)); 208 } 209 #endif 210 211 int 212 mm_sshkey_sign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp, 213 const u_char *data, size_t datalen, const char *hostkey_alg, u_int compat) 214 { 215 struct kex *kex = *pmonitor->m_pkex; 216 struct sshbuf *m; 217 u_int ndx = kex->host_key_index(key, 0, ssh); 218 int r; 219 220 debug3("%s entering", __func__); 221 222 if ((m = sshbuf_new()) == NULL) 223 fatal("%s: sshbuf_new failed", __func__); 224 if ((r = sshbuf_put_u32(m, ndx)) != 0 || 225 (r = sshbuf_put_string(m, data, datalen)) != 0 || 226 (r = sshbuf_put_cstring(m, hostkey_alg)) != 0 || 227 (r = sshbuf_put_u32(m, compat)) != 0) 228 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 229 230 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, m); 231 232 debug3("%s: waiting for MONITOR_ANS_SIGN", __func__); 233 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, m); 234 if ((r = sshbuf_get_string(m, sigp, lenp)) != 0) 235 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 236 sshbuf_free(m); 237 238 return (0); 239 } 240 241 struct passwd * 242 mm_getpwnamallow(struct ssh *ssh, const char *username) 243 { 244 struct sshbuf *m; 245 struct passwd *pw; 246 size_t len; 247 u_int i; 248 ServerOptions *newopts; 249 int r; 250 u_char ok; 251 const u_char *p; 252 253 debug3("%s entering", __func__); 254 255 if ((m = sshbuf_new()) == NULL) 256 fatal("%s: sshbuf_new failed", __func__); 257 if ((r = sshbuf_put_cstring(m, username)) != 0) 258 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 259 260 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, m); 261 262 debug3("%s: waiting for MONITOR_ANS_PWNAM", __func__); 263 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, m); 264 265 if ((r = sshbuf_get_u8(m, &ok)) != 0) 266 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 267 if (ok == 0) { 268 pw = NULL; 269 goto out; 270 } 271 272 /* XXX don't like passing struct passwd like this */ 273 pw = xcalloc(sizeof(*pw), 1); 274 if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0) 275 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 276 if (len != sizeof(*pw)) 277 fatal("%s: struct passwd size mismatch", __func__); 278 memcpy(pw, p, sizeof(*pw)); 279 280 if ((r = sshbuf_get_cstring(m, &pw->pw_name, NULL)) != 0 || 281 (r = sshbuf_get_cstring(m, &pw->pw_passwd, NULL)) != 0 || 282 (r = sshbuf_get_cstring(m, &pw->pw_gecos, NULL)) != 0 || 283 (r = sshbuf_get_cstring(m, &pw->pw_class, NULL)) != 0 || 284 (r = sshbuf_get_cstring(m, &pw->pw_dir, NULL)) != 0 || 285 (r = sshbuf_get_cstring(m, &pw->pw_shell, NULL)) != 0) 286 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 287 288 out: 289 /* copy options block as a Match directive may have changed some */ 290 if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0) 291 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 292 if (len != sizeof(*newopts)) 293 fatal("%s: option block size mismatch", __func__); 294 newopts = xcalloc(sizeof(*newopts), 1); 295 memcpy(newopts, p, sizeof(*newopts)); 296 297 #define M_CP_STROPT(x) do { \ 298 if (newopts->x != NULL) { \ 299 if ((r = sshbuf_get_cstring(m, \ 300 &newopts->x, NULL)) != 0) \ 301 fatal("%s: buffer error: %s", \ 302 __func__, ssh_err(r)); \ 303 } \ 304 } while (0) 305 #define M_CP_STRARRAYOPT(x, nx) do { \ 306 newopts->x = newopts->nx == 0 ? \ 307 NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \ 308 for (i = 0; i < newopts->nx; i++) { \ 309 if ((r = sshbuf_get_cstring(m, \ 310 &newopts->x[i], NULL)) != 0) \ 311 fatal("%s: buffer error: %s", \ 312 __func__, ssh_err(r)); \ 313 } \ 314 } while (0) 315 /* See comment in servconf.h */ 316 COPY_MATCH_STRING_OPTS(); 317 #undef M_CP_STROPT 318 #undef M_CP_STRARRAYOPT 319 320 copy_set_server_options(&options, newopts, 1); 321 log_change_level(options.log_level); 322 process_permitopen(ssh, &options); 323 free(newopts); 324 325 sshbuf_free(m); 326 327 return (pw); 328 } 329 330 char * 331 mm_auth2_read_banner(void) 332 { 333 struct sshbuf *m; 334 char *banner; 335 int r; 336 337 debug3("%s entering", __func__); 338 339 if ((m = sshbuf_new()) == NULL) 340 fatal("%s: sshbuf_new failed", __func__); 341 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, m); 342 sshbuf_reset(m); 343 344 mm_request_receive_expect(pmonitor->m_recvfd, 345 MONITOR_ANS_AUTH2_READ_BANNER, m); 346 if ((r = sshbuf_get_cstring(m, &banner, NULL)) != 0) 347 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 348 sshbuf_free(m); 349 350 /* treat empty banner as missing banner */ 351 if (strlen(banner) == 0) { 352 free(banner); 353 banner = NULL; 354 } 355 return (banner); 356 } 357 358 /* Inform the privileged process about service and style */ 359 360 void 361 mm_inform_authserv(char *service, char *style) 362 { 363 struct sshbuf *m; 364 int r; 365 366 debug3("%s entering", __func__); 367 368 if ((m = sshbuf_new()) == NULL) 369 fatal("%s: sshbuf_new failed", __func__); 370 if ((r = sshbuf_put_cstring(m, service)) != 0 || 371 (r = sshbuf_put_cstring(m, style ? style : "")) != 0) 372 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 373 374 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, m); 375 376 sshbuf_free(m); 377 } 378 379 /* Do the password authentication */ 380 int 381 mm_auth_password(struct ssh *ssh, char *password) 382 { 383 struct sshbuf *m; 384 int r, authenticated = 0; 385 386 debug3("%s entering", __func__); 387 388 if ((m = sshbuf_new()) == NULL) 389 fatal("%s: sshbuf_new failed", __func__); 390 if ((r = sshbuf_put_cstring(m, password)) != 0) 391 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 392 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, m); 393 394 debug3("%s: waiting for MONITOR_ANS_AUTHPASSWORD", __func__); 395 mm_request_receive_expect(pmonitor->m_recvfd, 396 MONITOR_ANS_AUTHPASSWORD, m); 397 398 if ((r = sshbuf_get_u32(m, &authenticated)) != 0) 399 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 400 401 sshbuf_free(m); 402 403 debug3("%s: user %sauthenticated", 404 __func__, authenticated ? "" : "not "); 405 return (authenticated); 406 } 407 408 int 409 mm_user_key_allowed(struct ssh *ssh, struct passwd *pw, struct sshkey *key, 410 int pubkey_auth_attempt, struct sshauthopt **authoptp) 411 { 412 return (mm_key_allowed(MM_USERKEY, NULL, NULL, key, 413 pubkey_auth_attempt, authoptp)); 414 } 415 416 int 417 mm_hostbased_key_allowed(struct ssh *ssh, struct passwd *pw, 418 const char *user, const char *host, struct sshkey *key) 419 { 420 return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0, NULL)); 421 } 422 423 int 424 mm_key_allowed(enum mm_keytype type, const char *user, const char *host, 425 struct sshkey *key, int pubkey_auth_attempt, struct sshauthopt **authoptp) 426 { 427 struct sshbuf *m; 428 int r, allowed = 0; 429 struct sshauthopt *opts = NULL; 430 431 debug3("%s entering", __func__); 432 433 if (authoptp != NULL) 434 *authoptp = NULL; 435 436 if ((m = sshbuf_new()) == NULL) 437 fatal("%s: sshbuf_new failed", __func__); 438 if ((r = sshbuf_put_u32(m, type)) != 0 || 439 (r = sshbuf_put_cstring(m, user ? user : "")) != 0 || 440 (r = sshbuf_put_cstring(m, host ? host : "")) != 0 || 441 (r = sshkey_puts(key, m)) != 0 || 442 (r = sshbuf_put_u32(m, pubkey_auth_attempt)) != 0) 443 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 444 445 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, m); 446 447 debug3("%s: waiting for MONITOR_ANS_KEYALLOWED", __func__); 448 mm_request_receive_expect(pmonitor->m_recvfd, 449 MONITOR_ANS_KEYALLOWED, m); 450 451 if ((r = sshbuf_get_u32(m, &allowed)) != 0) 452 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 453 if (allowed && type == MM_USERKEY) { 454 if ((r = sshauthopt_deserialise(m, &opts)) != 0) 455 fatal("%s: sshauthopt_deserialise: %s", 456 __func__, ssh_err(r)); 457 } 458 sshbuf_free(m); 459 460 if (authoptp != NULL) { 461 *authoptp = opts; 462 opts = NULL; 463 } 464 sshauthopt_free(opts); 465 466 return allowed; 467 } 468 469 /* 470 * This key verify needs to send the key type along, because the 471 * privileged parent makes the decision if the key is allowed 472 * for authentication. 473 */ 474 475 int 476 mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen, 477 const u_char *data, size_t datalen, const char *sigalg, u_int compat) 478 { 479 struct sshbuf *m; 480 u_int encoded_ret = 0; 481 int r; 482 483 debug3("%s entering", __func__); 484 485 486 if ((m = sshbuf_new()) == NULL) 487 fatal("%s: sshbuf_new failed", __func__); 488 if ((r = sshkey_puts(key, m)) != 0 || 489 (r = sshbuf_put_string(m, sig, siglen)) != 0 || 490 (r = sshbuf_put_string(m, data, datalen)) != 0 || 491 (r = sshbuf_put_cstring(m, sigalg == NULL ? "" : sigalg)) != 0) 492 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 493 494 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, m); 495 496 debug3("%s: waiting for MONITOR_ANS_KEYVERIFY", __func__); 497 mm_request_receive_expect(pmonitor->m_recvfd, 498 MONITOR_ANS_KEYVERIFY, m); 499 500 if ((r = sshbuf_get_u32(m, &encoded_ret)) != 0) 501 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 502 503 sshbuf_free(m); 504 505 if (encoded_ret != 0) 506 return SSH_ERR_SIGNATURE_INVALID; 507 return 0; 508 } 509 510 void 511 mm_send_keystate(struct ssh *ssh, struct monitor *monitor) 512 { 513 struct sshbuf *m; 514 int r; 515 516 if ((m = sshbuf_new()) == NULL) 517 fatal("%s: sshbuf_new failed", __func__); 518 if ((r = ssh_packet_get_state(ssh, m)) != 0) 519 fatal("%s: get_state failed: %s", 520 __func__, ssh_err(r)); 521 mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m); 522 debug3("%s: Finished sending state", __func__); 523 sshbuf_free(m); 524 } 525 526 int 527 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen) 528 { 529 struct sshbuf *m; 530 char *p, *msg; 531 int success = 0, tmp1 = -1, tmp2 = -1, r; 532 533 /* Kludge: ensure there are fds free to receive the pty/tty */ 534 if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 || 535 (tmp2 = dup(pmonitor->m_recvfd)) == -1) { 536 error("%s: cannot allocate fds for pty", __func__); 537 if (tmp1 > 0) 538 close(tmp1); 539 if (tmp2 > 0) 540 close(tmp2); 541 return 0; 542 } 543 close(tmp1); 544 close(tmp2); 545 546 if ((m = sshbuf_new()) == NULL) 547 fatal("%s: sshbuf_new failed", __func__); 548 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, m); 549 550 debug3("%s: waiting for MONITOR_ANS_PTY", __func__); 551 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, m); 552 553 if ((r = sshbuf_get_u32(m, &success)) != 0) 554 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 555 if (success == 0) { 556 debug3("%s: pty alloc failed", __func__); 557 sshbuf_free(m); 558 return (0); 559 } 560 if ((r = sshbuf_get_cstring(m, &p, NULL)) != 0 || 561 (r = sshbuf_get_cstring(m, &msg, NULL)) != 0) 562 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 563 sshbuf_free(m); 564 565 strlcpy(namebuf, p, namebuflen); /* Possible truncation */ 566 free(p); 567 568 if ((r = sshbuf_put(loginmsg, msg, strlen(msg))) != 0) 569 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 570 free(msg); 571 572 if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 || 573 (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1) 574 fatal("%s: receive fds failed", __func__); 575 576 /* Success */ 577 return (1); 578 } 579 580 void 581 mm_session_pty_cleanup2(Session *s) 582 { 583 struct sshbuf *m; 584 int r; 585 586 if (s->ttyfd == -1) 587 return; 588 if ((m = sshbuf_new()) == NULL) 589 fatal("%s: sshbuf_new failed", __func__); 590 if ((r = sshbuf_put_cstring(m, s->tty)) != 0) 591 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 592 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, m); 593 sshbuf_free(m); 594 595 /* closed dup'ed master */ 596 if (s->ptymaster != -1 && close(s->ptymaster) < 0) 597 error("close(s->ptymaster/%d): %s", 598 s->ptymaster, strerror(errno)); 599 600 /* unlink pty from session */ 601 s->ttyfd = -1; 602 } 603 604 /* Request process termination */ 605 606 void 607 mm_terminate(void) 608 { 609 struct sshbuf *m; 610 611 if ((m = sshbuf_new()) == NULL) 612 fatal("%s: sshbuf_new failed", __func__); 613 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, m); 614 sshbuf_free(m); 615 } 616 617 static void 618 mm_chall_setup(char **name, char **infotxt, u_int *numprompts, 619 char ***prompts, u_int **echo_on) 620 { 621 *name = xstrdup(""); 622 *infotxt = xstrdup(""); 623 *numprompts = 1; 624 *prompts = xcalloc(*numprompts, sizeof(char *)); 625 *echo_on = xcalloc(*numprompts, sizeof(u_int)); 626 (*echo_on)[0] = 0; 627 } 628 629 int 630 mm_bsdauth_query(void *ctx, char **name, char **infotxt, 631 u_int *numprompts, char ***prompts, u_int **echo_on) 632 { 633 struct sshbuf *m; 634 u_int success; 635 char *challenge; 636 int r; 637 638 debug3("%s: entering", __func__); 639 640 if ((m = sshbuf_new()) == NULL) 641 fatal("%s: sshbuf_new failed", __func__); 642 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, m); 643 644 mm_request_receive_expect(pmonitor->m_recvfd, 645 MONITOR_ANS_BSDAUTHQUERY, m); 646 if ((r = sshbuf_get_u32(m, &success)) != 0) 647 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 648 if (success == 0) { 649 debug3("%s: no challenge", __func__); 650 sshbuf_free(m); 651 return (-1); 652 } 653 654 /* Get the challenge, and format the response */ 655 if ((r = sshbuf_get_cstring(m, &challenge, NULL)) != 0) 656 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 657 sshbuf_free(m); 658 659 mm_chall_setup(name, infotxt, numprompts, prompts, echo_on); 660 (*prompts)[0] = challenge; 661 662 debug3("%s: received challenge: %s", __func__, challenge); 663 664 return (0); 665 } 666 667 int 668 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses) 669 { 670 struct sshbuf *m; 671 int r, authok; 672 673 debug3("%s: entering", __func__); 674 if (numresponses != 1) 675 return (-1); 676 677 if ((m = sshbuf_new()) == NULL) 678 fatal("%s: sshbuf_new failed", __func__); 679 if ((r = sshbuf_put_cstring(m, responses[0])) != 0) 680 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 681 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, m); 682 683 mm_request_receive_expect(pmonitor->m_recvfd, 684 MONITOR_ANS_BSDAUTHRESPOND, m); 685 686 if ((r = sshbuf_get_u32(m, &authok)) != 0) 687 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 688 sshbuf_free(m); 689 690 return ((authok == 0) ? -1 : 0); 691 } 692 693 #ifdef GSSAPI 694 OM_uint32 695 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid) 696 { 697 struct sshbuf *m; 698 OM_uint32 major; 699 int r; 700 701 /* Client doesn't get to see the context */ 702 *ctx = NULL; 703 704 if ((m = sshbuf_new()) == NULL) 705 fatal("%s: sshbuf_new failed", __func__); 706 if ((r = sshbuf_put_string(m, goid->elements, goid->length)) != 0) 707 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 708 709 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, m); 710 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, m); 711 712 if ((r = sshbuf_get_u32(m, &major)) != 0) 713 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 714 715 sshbuf_free(m); 716 return (major); 717 } 718 719 OM_uint32 720 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in, 721 gss_buffer_desc *out, OM_uint32 *flagsp) 722 { 723 struct sshbuf *m; 724 OM_uint32 major; 725 u_int flags; 726 int r; 727 728 if ((m = sshbuf_new()) == NULL) 729 fatal("%s: sshbuf_new failed", __func__); 730 if ((r = sshbuf_put_string(m, in->value, in->length)) != 0) 731 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 732 733 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, m); 734 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, m); 735 736 if ((r = sshbuf_get_u32(m, &major)) != 0 || 737 (r = ssh_gssapi_get_buffer_desc(m, out)) != 0) 738 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 739 if (flagsp != NULL) { 740 if ((r = sshbuf_get_u32(m, &flags)) != 0) 741 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 742 *flagsp = flags; 743 } 744 745 sshbuf_free(m); 746 747 return (major); 748 } 749 750 OM_uint32 751 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) 752 { 753 struct sshbuf *m; 754 OM_uint32 major; 755 int r; 756 757 if ((m = sshbuf_new()) == NULL) 758 fatal("%s: sshbuf_new failed", __func__); 759 if ((r = sshbuf_put_string(m, gssbuf->value, gssbuf->length)) != 0 || 760 (r = sshbuf_put_string(m, gssmic->value, gssmic->length)) != 0) 761 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 762 763 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, m); 764 mm_request_receive_expect(pmonitor->m_recvfd, 765 MONITOR_ANS_GSSCHECKMIC, m); 766 767 if ((r = sshbuf_get_u32(m, &major)) != 0) 768 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 769 sshbuf_free(m); 770 return(major); 771 } 772 773 int 774 mm_ssh_gssapi_userok(char *user) 775 { 776 struct sshbuf *m; 777 int r, authenticated = 0; 778 779 if ((m = sshbuf_new()) == NULL) 780 fatal("%s: sshbuf_new failed", __func__); 781 782 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, m); 783 mm_request_receive_expect(pmonitor->m_recvfd, 784 MONITOR_ANS_GSSUSEROK, m); 785 786 if ((r = sshbuf_get_u32(m, &authenticated)) != 0) 787 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 788 789 sshbuf_free(m); 790 debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not "); 791 return (authenticated); 792 } 793 #endif /* GSSAPI */ 794