1 /* $NetBSD: monitor_wrap.c,v 1.34 2023/12/20 17:15:20 christos Exp $ */ 2 /* $OpenBSD: monitor_wrap.c,v 1.129 2023/12/18 14:45:49 djm Exp $ */ 3 4 /* 5 * Copyright 2002 Niels Provos <provos@citi.umich.edu> 6 * Copyright 2002 Markus Friedl <markus@openbsd.org> 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #include "includes.h" 31 __RCSID("$NetBSD: monitor_wrap.c,v 1.34 2023/12/20 17:15:20 christos Exp $"); 32 #include <sys/types.h> 33 #include <sys/uio.h> 34 #include <sys/queue.h> 35 36 #include <errno.h> 37 #include <pwd.h> 38 #include <signal.h> 39 #include <stdio.h> 40 #include <string.h> 41 #include <stdarg.h> 42 #include <unistd.h> 43 44 #ifdef WITH_OPENSSL 45 #include <openssl/bn.h> 46 #include <openssl/dh.h> 47 #endif 48 49 #include "xmalloc.h" 50 #include "ssh.h" 51 #ifdef WITH_OPENSSL 52 #include "dh.h" 53 #endif 54 #include "sshbuf.h" 55 #include "sshkey.h" 56 #include "cipher.h" 57 #include "kex.h" 58 #include "hostfile.h" 59 #include "auth.h" 60 #include "auth-options.h" 61 #include "packet.h" 62 #include "mac.h" 63 #include "log.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 #ifdef USE_PAM 72 #include "misc.h" 73 #include "servconf.h" 74 #include <security/pam_appl.h> 75 #endif 76 #include "misc.h" 77 78 #include "channels.h" 79 #include "session.h" 80 #include "servconf.h" 81 82 #include "ssherr.h" 83 84 /* Imports */ 85 extern struct monitor *pmonitor; 86 extern struct sshbuf *loginmsg; 87 extern ServerOptions options; 88 89 void 90 mm_log_handler(LogLevel level, int forced, const char *msg, void *ctx) 91 { 92 struct sshbuf *log_msg; 93 struct monitor *mon = (struct monitor *)ctx; 94 int r; 95 size_t len; 96 97 if (mon->m_log_sendfd == -1) 98 fatal_f("no log channel"); 99 100 if ((log_msg = sshbuf_new()) == NULL) 101 fatal_f("sshbuf_new failed"); 102 103 if ((r = sshbuf_put_u32(log_msg, 0)) != 0 || /* length; filled below */ 104 (r = sshbuf_put_u32(log_msg, level)) != 0 || 105 (r = sshbuf_put_u32(log_msg, forced)) != 0 || 106 (r = sshbuf_put_cstring(log_msg, msg)) != 0) 107 fatal_fr(r, "assemble"); 108 if ((len = sshbuf_len(log_msg)) < 4 || len > 0xffffffff) 109 fatal_f("bad length %zu", len); 110 POKE_U32(sshbuf_mutable_ptr(log_msg), len - 4); 111 if (atomicio(vwrite, mon->m_log_sendfd, 112 sshbuf_mutable_ptr(log_msg), len) != len) 113 fatal_f("write: %s", strerror(errno)); 114 sshbuf_free(log_msg); 115 } 116 117 int 118 mm_is_monitor(void) 119 { 120 /* 121 * m_pid is only set in the privileged part, and 122 * points to the unprivileged child. 123 */ 124 return (pmonitor && pmonitor->m_pid > 0); 125 } 126 127 void 128 mm_request_send(int sock, enum monitor_reqtype type, struct sshbuf *m) 129 { 130 size_t mlen = sshbuf_len(m); 131 u_char buf[5]; 132 133 debug3_f("entering, type %d", type); 134 135 if (mlen >= 0xffffffff) 136 fatal_f("bad length %zu", mlen); 137 POKE_U32(buf, mlen + 1); 138 buf[4] = (u_char) type; /* 1st byte of payload is mesg-type */ 139 if (atomicio(vwrite, sock, buf, sizeof(buf)) != sizeof(buf)) 140 fatal_f("write: %s", strerror(errno)); 141 if (atomicio(vwrite, sock, sshbuf_mutable_ptr(m), mlen) != mlen) 142 fatal_f("write: %s", strerror(errno)); 143 } 144 145 void 146 mm_request_receive(int sock, struct sshbuf *m) 147 { 148 u_char buf[4], *p = NULL; 149 u_int msg_len; 150 int r; 151 152 debug3_f("entering"); 153 154 if (atomicio(read, sock, buf, sizeof(buf)) != sizeof(buf)) { 155 if (errno == EPIPE) 156 cleanup_exit(254); 157 fatal_f("read: %s", strerror(errno)); 158 } 159 msg_len = PEEK_U32(buf); 160 if (msg_len > 256 * 1024) 161 fatal_f("read: bad msg_len %d", msg_len); 162 sshbuf_reset(m); 163 if ((r = sshbuf_reserve(m, msg_len, &p)) != 0) 164 fatal_fr(r, "reserve"); 165 if (atomicio(read, sock, p, msg_len) != msg_len) 166 fatal_f("read: %s", strerror(errno)); 167 } 168 169 void 170 mm_request_receive_expect(int sock, enum monitor_reqtype type, struct sshbuf *m) 171 { 172 u_char rtype; 173 int r; 174 175 debug3_f("entering, type %d", type); 176 177 mm_request_receive(sock, m); 178 if ((r = sshbuf_get_u8(m, &rtype)) != 0) 179 fatal_fr(r, "parse"); 180 if (rtype != type) 181 fatal_f("read: rtype %d != type %d", rtype, type); 182 } 183 184 #ifdef WITH_OPENSSL 185 DH * 186 mm_choose_dh(int min, int nbits, int max) 187 { 188 BIGNUM *p, *g; 189 int r; 190 u_char success = 0; 191 struct sshbuf *m; 192 193 if ((m = sshbuf_new()) == NULL) 194 fatal_f("sshbuf_new failed"); 195 if ((r = sshbuf_put_u32(m, min)) != 0 || 196 (r = sshbuf_put_u32(m, nbits)) != 0 || 197 (r = sshbuf_put_u32(m, max)) != 0) 198 fatal_fr(r, "assemble"); 199 200 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_MODULI, m); 201 202 debug3_f("waiting for MONITOR_ANS_MODULI"); 203 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_MODULI, m); 204 205 if ((r = sshbuf_get_u8(m, &success)) != 0) 206 fatal_fr(r, "parse success"); 207 if (success == 0) 208 fatal_f("MONITOR_ANS_MODULI failed"); 209 210 if ((r = sshbuf_get_bignum2(m, &p)) != 0 || 211 (r = sshbuf_get_bignum2(m, &g)) != 0) 212 fatal_fr(r, "parse group"); 213 214 debug3_f("remaining %zu", sshbuf_len(m)); 215 sshbuf_free(m); 216 217 return (dh_new_group(g, p)); 218 } 219 #endif 220 221 int 222 mm_sshkey_sign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp, 223 const u_char *data, size_t datalen, const char *hostkey_alg, 224 const char *sk_provider, const char *sk_pin, u_int compat) 225 { 226 struct kex *kex = *pmonitor->m_pkex; 227 struct sshbuf *m; 228 u_int ndx = kex->host_key_index(key, 0, ssh); 229 int r; 230 231 debug3_f("entering"); 232 if ((m = sshbuf_new()) == NULL) 233 fatal_f("sshbuf_new failed"); 234 if ((r = sshbuf_put_u32(m, ndx)) != 0 || 235 (r = sshbuf_put_string(m, data, datalen)) != 0 || 236 (r = sshbuf_put_cstring(m, hostkey_alg)) != 0 || 237 (r = sshbuf_put_u32(m, compat)) != 0) 238 fatal_fr(r, "assemble"); 239 240 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, m); 241 242 debug3_f("waiting for MONITOR_ANS_SIGN"); 243 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, m); 244 if ((r = sshbuf_get_string(m, sigp, lenp)) != 0) 245 fatal_fr(r, "parse"); 246 sshbuf_free(m); 247 248 return (0); 249 } 250 251 #define GETPW(b, id) \ 252 do { \ 253 if ((r = sshbuf_get_string_direct(b, &p, &len)) != 0) \ 254 fatal_fr(r, "parse pw %s", #id); \ 255 if (len != sizeof(pw->id)) \ 256 fatal_fr(r, "bad length for %s", #id); \ 257 memcpy(&pw->id, p, len); \ 258 } while (0) 259 260 struct passwd * 261 mm_getpwnamallow(struct ssh *ssh, const char *username) 262 { 263 struct sshbuf *m; 264 struct passwd *pw; 265 size_t len; 266 u_int i; 267 ServerOptions *newopts; 268 int r; 269 u_char ok; 270 const u_char *p; 271 272 debug3_f("entering"); 273 274 if ((m = sshbuf_new()) == NULL) 275 fatal_f("sshbuf_new failed"); 276 if ((r = sshbuf_put_cstring(m, username)) != 0) 277 fatal_fr(r, "assemble"); 278 279 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, m); 280 281 debug3_f("waiting for MONITOR_ANS_PWNAM"); 282 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, m); 283 284 if ((r = sshbuf_get_u8(m, &ok)) != 0) 285 fatal_fr(r, "parse success"); 286 if (ok == 0) { 287 pw = NULL; 288 goto out; 289 } 290 291 pw = xcalloc(sizeof(*pw), 1); 292 GETPW(m, pw_uid); 293 GETPW(m, pw_gid); 294 GETPW(m, pw_change); 295 GETPW(m, pw_expire); 296 if ((r = sshbuf_get_cstring(m, &pw->pw_name, NULL)) != 0 || 297 (r = sshbuf_get_cstring(m, &pw->pw_passwd, NULL)) != 0 || 298 (r = sshbuf_get_cstring(m, &pw->pw_gecos, NULL)) != 0 || 299 (r = sshbuf_get_cstring(m, &pw->pw_class, NULL)) != 0 || 300 (r = sshbuf_get_cstring(m, &pw->pw_dir, NULL)) != 0 || 301 (r = sshbuf_get_cstring(m, &pw->pw_shell, NULL)) != 0) 302 fatal_fr(r, "parse pw"); 303 304 out: 305 /* copy options block as a Match directive may have changed some */ 306 if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0) 307 fatal_fr(r, "parse opts"); 308 if (len != sizeof(*newopts)) 309 fatal_f("option block size mismatch"); 310 newopts = xcalloc(sizeof(*newopts), 1); 311 memcpy(newopts, p, sizeof(*newopts)); 312 313 #define M_CP_STROPT(x) do { \ 314 if (newopts->x != NULL && \ 315 (r = sshbuf_get_cstring(m, &newopts->x, NULL)) != 0) \ 316 fatal_fr(r, "parse %s", #x); \ 317 } while (0) 318 #define M_CP_STRARRAYOPT(x, nx) do { \ 319 newopts->x = newopts->nx == 0 ? \ 320 NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \ 321 for (i = 0; i < newopts->nx; i++) { \ 322 if ((r = sshbuf_get_cstring(m, \ 323 &newopts->x[i], NULL)) != 0) \ 324 fatal_fr(r, "parse %s", #x); \ 325 } \ 326 } while (0) 327 /* See comment in servconf.h */ 328 COPY_MATCH_STRING_OPTS(); 329 #undef M_CP_STROPT 330 #undef M_CP_STRARRAYOPT 331 332 copy_set_server_options(&options, newopts, 1); 333 log_change_level(options.log_level); 334 log_verbose_reset(); 335 for (i = 0; i < options.num_log_verbose; i++) 336 log_verbose_add(options.log_verbose[i]); 337 process_permitopen(ssh, &options); 338 process_channel_timeouts(ssh, &options); 339 kex_set_server_sig_algs(ssh, options.pubkey_accepted_algos); 340 free(newopts); 341 sshbuf_free(m); 342 343 return (pw); 344 } 345 346 char * 347 mm_auth2_read_banner(void) 348 { 349 struct sshbuf *m; 350 char *banner; 351 int r; 352 353 debug3_f("entering"); 354 355 if ((m = sshbuf_new()) == NULL) 356 fatal_f("sshbuf_new failed"); 357 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, m); 358 sshbuf_reset(m); 359 360 mm_request_receive_expect(pmonitor->m_recvfd, 361 MONITOR_ANS_AUTH2_READ_BANNER, m); 362 if ((r = sshbuf_get_cstring(m, &banner, NULL)) != 0) 363 fatal_fr(r, "parse"); 364 sshbuf_free(m); 365 366 /* treat empty banner as missing banner */ 367 if (strlen(banner) == 0) { 368 free(banner); 369 banner = NULL; 370 } 371 return (banner); 372 } 373 374 /* Inform the privileged process about service and style */ 375 376 void 377 mm_inform_authserv(char *service, char *style) 378 { 379 struct sshbuf *m; 380 int r; 381 382 debug3_f("entering"); 383 384 if ((m = sshbuf_new()) == NULL) 385 fatal_f("sshbuf_new failed"); 386 if ((r = sshbuf_put_cstring(m, service)) != 0 || 387 (r = sshbuf_put_cstring(m, style ? style : "")) != 0) 388 fatal_fr(r, "assemble"); 389 390 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, m); 391 392 sshbuf_free(m); 393 } 394 395 /* Do the password authentication */ 396 int 397 mm_auth_password(struct ssh *ssh, const char *password) 398 { 399 struct sshbuf *m; 400 int r; 401 u_int authenticated = 0; 402 403 debug3_f("entering"); 404 405 if ((m = sshbuf_new()) == NULL) 406 fatal_f("sshbuf_new failed"); 407 if ((r = sshbuf_put_cstring(m, password)) != 0) 408 fatal_fr(r, "assemble"); 409 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, m); 410 411 debug3_f("waiting for MONITOR_ANS_AUTHPASSWORD"); 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_fr(r, "parse"); 417 418 sshbuf_free(m); 419 420 debug3_f("user %sauthenticated", authenticated ? "" : "not "); 421 return (authenticated); 422 } 423 424 int 425 mm_user_key_allowed(struct ssh *ssh, struct passwd *pw, struct sshkey *key, 426 int pubkey_auth_attempt, struct sshauthopt **authoptp) 427 { 428 return (mm_key_allowed(MM_USERKEY, NULL, NULL, key, 429 pubkey_auth_attempt, authoptp)); 430 } 431 432 int 433 mm_hostbased_key_allowed(struct ssh *ssh, struct passwd *pw, 434 const char *user, const char *host, struct sshkey *key) 435 { 436 return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0, NULL)); 437 } 438 439 int 440 mm_key_allowed(enum mm_keytype type, const char *user, const char *host, 441 struct sshkey *key, int pubkey_auth_attempt, struct sshauthopt **authoptp) 442 { 443 struct sshbuf *m; 444 int r; 445 u_int allowed = 0; 446 struct sshauthopt *opts = NULL; 447 448 debug3_f("entering"); 449 450 if (authoptp != NULL) 451 *authoptp = NULL; 452 453 if ((m = sshbuf_new()) == NULL) 454 fatal_f("sshbuf_new failed"); 455 if ((r = sshbuf_put_u32(m, type)) != 0 || 456 (r = sshbuf_put_cstring(m, user ? user : "")) != 0 || 457 (r = sshbuf_put_cstring(m, host ? host : "")) != 0 || 458 (r = sshkey_puts(key, m)) != 0 || 459 (r = sshbuf_put_u32(m, pubkey_auth_attempt)) != 0) 460 fatal_fr(r, "assemble"); 461 462 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, m); 463 464 debug3_f("waiting for MONITOR_ANS_KEYALLOWED"); 465 mm_request_receive_expect(pmonitor->m_recvfd, 466 MONITOR_ANS_KEYALLOWED, m); 467 468 if ((r = sshbuf_get_u32(m, &allowed)) != 0) 469 fatal_fr(r, "parse"); 470 if (allowed && type == MM_USERKEY && 471 (r = sshauthopt_deserialise(m, &opts)) != 0) 472 fatal_fr(r, "sshauthopt_deserialise"); 473 sshbuf_free(m); 474 475 if (authoptp != NULL) { 476 *authoptp = opts; 477 opts = NULL; 478 } 479 sshauthopt_free(opts); 480 481 return allowed; 482 } 483 484 /* 485 * This key verify needs to send the key type along, because the 486 * privileged parent makes the decision if the key is allowed 487 * for authentication. 488 */ 489 490 int 491 mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen, 492 const u_char *data, size_t datalen, const char *sigalg, u_int compat, 493 struct sshkey_sig_details **sig_detailsp) 494 { 495 struct sshbuf *m; 496 u_int encoded_ret = 0; 497 int r; 498 u_char sig_details_present, flags; 499 u_int counter; 500 501 debug3_f("entering"); 502 503 if (sig_detailsp != NULL) 504 *sig_detailsp = NULL; 505 if ((m = sshbuf_new()) == NULL) 506 fatal_f("sshbuf_new failed"); 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_fr(r, "assemble"); 512 513 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, m); 514 515 debug3_f("waiting for MONITOR_ANS_KEYVERIFY"); 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 (r = sshbuf_get_u8(m, &sig_details_present)) != 0) 521 fatal_fr(r, "parse"); 522 if (sig_details_present && encoded_ret == 0) { 523 if ((r = sshbuf_get_u32(m, &counter)) != 0 || 524 (r = sshbuf_get_u8(m, &flags)) != 0) 525 fatal_fr(r, "parse sig_details"); 526 if (sig_detailsp != NULL) { 527 *sig_detailsp = xcalloc(1, sizeof(**sig_detailsp)); 528 (*sig_detailsp)->sk_counter = counter; 529 (*sig_detailsp)->sk_flags = flags; 530 } 531 } 532 533 sshbuf_free(m); 534 535 if (encoded_ret != 0) 536 return SSH_ERR_SIGNATURE_INVALID; 537 return 0; 538 } 539 540 void 541 mm_send_keystate(struct ssh *ssh, struct monitor *monitor) 542 { 543 struct sshbuf *m; 544 int r; 545 546 if ((m = sshbuf_new()) == NULL) 547 fatal_f("sshbuf_new failed"); 548 if ((r = ssh_packet_get_state(ssh, m)) != 0) 549 fatal_fr(r, "ssh_packet_get_state"); 550 mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m); 551 debug3_f("Finished sending state"); 552 sshbuf_free(m); 553 } 554 555 int 556 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen) 557 { 558 struct sshbuf *m; 559 char *p, *msg; 560 u_int success = 0; 561 int tmp1 = -1, tmp2 = -1, r; 562 563 /* Kludge: ensure there are fds free to receive the pty/tty */ 564 if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 || 565 (tmp2 = dup(pmonitor->m_recvfd)) == -1) { 566 error_f("cannot allocate fds for pty"); 567 if (tmp1 >= 0) 568 close(tmp1); 569 return 0; 570 } 571 close(tmp1); 572 close(tmp2); 573 574 if ((m = sshbuf_new()) == NULL) 575 fatal_f("sshbuf_new failed"); 576 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, m); 577 578 debug3_f("waiting for MONITOR_ANS_PTY"); 579 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, m); 580 581 if ((r = sshbuf_get_u32(m, &success)) != 0) 582 fatal_fr(r, "parse success"); 583 if (success == 0) { 584 debug3_f("pty alloc failed"); 585 sshbuf_free(m); 586 return (0); 587 } 588 if ((r = sshbuf_get_cstring(m, &p, NULL)) != 0 || 589 (r = sshbuf_get_cstring(m, &msg, NULL)) != 0) 590 fatal_fr(r, "parse"); 591 sshbuf_free(m); 592 593 strlcpy(namebuf, p, namebuflen); /* Possible truncation */ 594 free(p); 595 596 if ((r = sshbuf_put(loginmsg, msg, strlen(msg))) != 0) 597 fatal_fr(r, "put loginmsg"); 598 free(msg); 599 600 if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 || 601 (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1) 602 fatal_f("receive fds failed"); 603 604 /* Success */ 605 return (1); 606 } 607 608 void 609 mm_session_pty_cleanup2(Session *s) 610 { 611 struct sshbuf *m; 612 int r; 613 614 if (s->ttyfd == -1) 615 return; 616 if ((m = sshbuf_new()) == NULL) 617 fatal_f("sshbuf_new failed"); 618 if ((r = sshbuf_put_cstring(m, s->tty)) != 0) 619 fatal_fr(r, "assmble"); 620 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, m); 621 sshbuf_free(m); 622 623 /* closed dup'ed master */ 624 if (s->ptymaster != -1 && close(s->ptymaster) == -1) 625 error("close(s->ptymaster/%d): %s", 626 s->ptymaster, strerror(errno)); 627 628 /* unlink pty from session */ 629 s->ttyfd = -1; 630 } 631 632 #ifdef USE_PAM 633 void 634 mm_start_pam(struct ssh *ssh) 635 { 636 struct sshbuf *m; 637 638 debug3("%s entering", __func__); 639 if (!options.use_pam) 640 fatal("UsePAM=no, but ended up in %s anyway", __func__); 641 642 if ((m = sshbuf_new()) == NULL) 643 fatal("%s: sshbuf_new failed", __func__); 644 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, m); 645 646 sshbuf_free(m); 647 } 648 649 u_int 650 mm_do_pam_account(void) 651 { 652 struct sshbuf *m; 653 int r; 654 u_int ret; 655 size_t len; 656 char *msg; 657 658 debug3("%s entering", __func__); 659 if (!options.use_pam) 660 fatal("UsePAM=no, but ended up in %s anyway", __func__); 661 662 if ((m = sshbuf_new()) == NULL) 663 fatal("%s: sshbuf_new failed", __func__); 664 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, m); 665 666 mm_request_receive_expect(pmonitor->m_recvfd, 667 MONITOR_ANS_PAM_ACCOUNT, m); 668 if ((r = sshbuf_get_u32(m, &ret)) != 0 || 669 (r = sshbuf_get_cstring(m, &msg, &len)) != 0) 670 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 671 sshbuf_put_cstring(loginmsg, msg); 672 free(msg); 673 674 sshbuf_free(m); 675 676 debug3("%s returning %d", __func__, ret); 677 678 return (ret); 679 } 680 681 void * 682 mm_sshpam_init_ctx(Authctxt *authctxt) 683 { 684 struct sshbuf *m; 685 u_int success; 686 int r; 687 688 debug3("%s", __func__); 689 if ((m = sshbuf_new()) == NULL) 690 fatal("%s: sshbuf_new failed", __func__); 691 sshbuf_put_cstring(m, authctxt->user); 692 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, m); 693 debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__); 694 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_INIT_CTX, m); 695 if ((r = sshbuf_get_u32(m, &success)) != 0) 696 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 697 if (success == 0) { 698 debug3("%s: pam_init_ctx failed", __func__); 699 sshbuf_free(m); 700 return (NULL); 701 } 702 sshbuf_free(m); 703 return (authctxt); 704 } 705 706 int 707 mm_sshpam_query(void *ctx, char **name, char **info, 708 u_int *num, char ***prompts, u_int **echo_on) 709 { 710 struct sshbuf *m; 711 u_int i, ret; 712 int r; 713 714 debug3("%s", __func__); 715 if ((m = sshbuf_new()) == NULL) 716 fatal("%s: sshbuf_new failed", __func__); 717 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_QUERY, m); 718 debug3("%s: waiting for MONITOR_ANS_PAM_QUERY", __func__); 719 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_QUERY, m); 720 if ((r = sshbuf_get_u32(m, &ret)) != 0) 721 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 722 debug3("%s: pam_query returned %d", __func__, ret); 723 if ((r = sshbuf_get_cstring(m, name, NULL)) != 0 || 724 (r = sshbuf_get_cstring(m, info, NULL)) != 0 || 725 (r = sshbuf_get_u32(m, num)) != 0) 726 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 727 if (*num > PAM_MAX_NUM_MSG) 728 fatal("%s: received %u PAM messages, expected <= %u", 729 __func__, *num, PAM_MAX_NUM_MSG); 730 *prompts = xcalloc((*num + 1), sizeof(char *)); 731 *echo_on = xcalloc((*num + 1), sizeof(u_int)); 732 for (i = 0; i < *num; ++i) { 733 if ((r = sshbuf_get_cstring(m, &(*prompts)[i], NULL)) != 0 || 734 (r = sshbuf_get_u32(m, (echo_on)[i])) != 0) 735 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 736 } 737 sshbuf_free(m); 738 return (ret); 739 } 740 741 int 742 mm_sshpam_respond(void *ctx, u_int num, char **resp) 743 { 744 struct sshbuf *m; 745 int r; 746 u_int i; 747 u_int ret; 748 749 debug3("%s", __func__); 750 if ((m = sshbuf_new()) == NULL) 751 fatal("%s: sshbuf_new failed", __func__); 752 sshbuf_put_u32(m, num); 753 for (i = 0; i < num; ++i) 754 sshbuf_put_cstring(m, resp[i]); 755 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, m); 756 debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__); 757 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_RESPOND, m); 758 if ((r = sshbuf_get_u32(m, &ret)) != 0) 759 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 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, MONITOR_ANS_PAM_FREE_CTX, m); 776 sshbuf_free(m); 777 } 778 #endif /* USE_PAM */ 779 780 /* Request process termination */ 781 782 void 783 mm_terminate(void) 784 { 785 struct sshbuf *m; 786 787 if ((m = sshbuf_new()) == NULL) 788 fatal_f("sshbuf_new failed"); 789 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, m); 790 sshbuf_free(m); 791 } 792 793 #if defined(BSD_AUTH) || defined(SKEY) 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 #ifdef BSD_AUTH 807 int 808 mm_bsdauth_query(void *ctx, char **name, char **infotxt, 809 u_int *numprompts, char ***prompts, u_int **echo_on) 810 { 811 struct sshbuf *m; 812 u_int success; 813 char *challenge; 814 int r; 815 816 debug3_f("entering"); 817 818 if ((m = sshbuf_new()) == NULL) 819 fatal_f("sshbuf_new failed"); 820 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, m); 821 822 mm_request_receive_expect(pmonitor->m_recvfd, 823 MONITOR_ANS_BSDAUTHQUERY, m); 824 if ((r = sshbuf_get_u32(m, &success)) != 0) 825 fatal_fr(r, "parse success"); 826 if (success == 0) { 827 debug3_f("no challenge"); 828 sshbuf_free(m); 829 return (-1); 830 } 831 832 /* Get the challenge, and format the response */ 833 if ((r = sshbuf_get_cstring(m, &challenge, NULL)) != 0) 834 fatal_fr(r, "parse challenge"); 835 sshbuf_free(m); 836 837 mm_chall_setup(name, infotxt, numprompts, prompts, echo_on); 838 (*prompts)[0] = challenge; 839 840 debug3_f("received challenge: %s", challenge); 841 842 return (0); 843 } 844 845 int 846 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses) 847 { 848 struct sshbuf *m; 849 int r, authok; 850 851 debug3_f("entering"); 852 if (numresponses != 1) 853 return (-1); 854 855 if ((m = sshbuf_new()) == NULL) 856 fatal_f("sshbuf_new failed"); 857 if ((r = sshbuf_put_cstring(m, responses[0])) != 0) 858 fatal_fr(r, "assemble"); 859 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, m); 860 861 mm_request_receive_expect(pmonitor->m_recvfd, 862 MONITOR_ANS_BSDAUTHRESPOND, m); 863 864 if ((r = sshbuf_get_u32(m, &authok)) != 0) 865 fatal_fr(r, "parse"); 866 sshbuf_free(m); 867 868 return ((authok == 0) ? -1 : 0); 869 } 870 #endif 871 872 #ifdef SKEY 873 int 874 mm_skey_query(void *ctx, char **name, char **infotxt, 875 u_int *numprompts, char ***prompts, u_int **echo_on) 876 { 877 struct sshbuf m; 878 u_int success; 879 char *challenge; 880 881 debug3("%s: entering", __func__); 882 883 sshbuf_new(&m); 884 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYQUERY, &m); 885 886 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SKEYQUERY, 887 &m); 888 success = sshbuf_get_int(&m); 889 if (success == 0) { 890 debug3("%s: no challenge", __func__); 891 sshbuf_free(&m); 892 return (-1); 893 } 894 895 /* Get the challenge, and format the response */ 896 challenge = sshbuf_get_string(&m, NULL); 897 sshbuf_free(&m); 898 899 debug3("%s: received challenge: %s", __func__, challenge); 900 901 mm_chall_setup(name, infotxt, numprompts, prompts, echo_on); 902 903 xasprintf(*prompts, "%s%s", challenge, SKEY_PROMPT); 904 free(challenge); 905 906 return (0); 907 } 908 909 int 910 mm_skey_respond(void *ctx, u_int numresponses, char **responses) 911 { 912 struct sshbuf m; 913 int authok; 914 915 debug3("%s: entering", __func__); 916 if (numresponses != 1) 917 return (-1); 918 919 sshbuf_new(&m); 920 sshbuf_put_cstring(&m, responses[0]); 921 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYRESPOND, &m); 922 923 mm_request_receive_expect(pmonitor->m_recvfd, 924 MONITOR_ANS_SKEYRESPOND, &m); 925 926 authok = sshbuf_get_int(&m); 927 sshbuf_free(&m); 928 929 return ((authok == 0) ? -1 : 0); 930 } 931 #endif /* SKEY */ 932 #endif /* BSDAUTH || SKEY */ 933 934 #ifdef GSSAPI 935 OM_uint32 936 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid) 937 { 938 struct sshbuf *m; 939 OM_uint32 major; 940 int r; 941 942 /* Client doesn't get to see the context */ 943 *ctx = NULL; 944 945 if ((m = sshbuf_new()) == NULL) 946 fatal_f("sshbuf_new failed"); 947 if ((r = sshbuf_put_string(m, goid->elements, goid->length)) != 0) 948 fatal_fr(r, "assemble"); 949 950 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, m); 951 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, m); 952 953 if ((r = sshbuf_get_u32(m, &major)) != 0) 954 fatal_fr(r, "parse"); 955 956 sshbuf_free(m); 957 return (major); 958 } 959 960 OM_uint32 961 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in, 962 gss_buffer_desc *out, OM_uint32 *flagsp) 963 { 964 struct sshbuf *m; 965 OM_uint32 major; 966 u_int flags; 967 int r; 968 969 if ((m = sshbuf_new()) == NULL) 970 fatal_f("sshbuf_new failed"); 971 if ((r = sshbuf_put_string(m, in->value, in->length)) != 0) 972 fatal_fr(r, "assemble"); 973 974 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, m); 975 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, m); 976 977 if ((r = sshbuf_get_u32(m, &major)) != 0 || 978 (r = ssh_gssapi_get_buffer_desc(m, out)) != 0) 979 fatal_fr(r, "parse"); 980 if (flagsp != NULL) { 981 if ((r = sshbuf_get_u32(m, &flags)) != 0) 982 fatal_fr(r, "parse flags"); 983 *flagsp = flags; 984 } 985 986 sshbuf_free(m); 987 988 return (major); 989 } 990 991 OM_uint32 992 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) 993 { 994 struct sshbuf *m; 995 OM_uint32 major; 996 int r; 997 998 if ((m = sshbuf_new()) == NULL) 999 fatal_f("sshbuf_new failed"); 1000 if ((r = sshbuf_put_string(m, gssbuf->value, gssbuf->length)) != 0 || 1001 (r = sshbuf_put_string(m, gssmic->value, gssmic->length)) != 0) 1002 fatal_fr(r, "assemble"); 1003 1004 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, m); 1005 mm_request_receive_expect(pmonitor->m_recvfd, 1006 MONITOR_ANS_GSSCHECKMIC, m); 1007 1008 if ((r = sshbuf_get_u32(m, &major)) != 0) 1009 fatal_fr(r, "parse"); 1010 sshbuf_free(m); 1011 return(major); 1012 } 1013 1014 int 1015 mm_ssh_gssapi_userok(char *user) 1016 { 1017 struct sshbuf *m; 1018 int r; 1019 u_int authenticated = 0; 1020 1021 if ((m = sshbuf_new()) == NULL) 1022 fatal_f("sshbuf_new failed"); 1023 1024 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, m); 1025 mm_request_receive_expect(pmonitor->m_recvfd, 1026 MONITOR_ANS_GSSUSEROK, m); 1027 1028 if ((r = sshbuf_get_u32(m, &authenticated)) != 0) 1029 fatal_fr(r, "parse"); 1030 1031 sshbuf_free(m); 1032 debug3_f("user %sauthenticated", authenticated ? "" : "not "); 1033 return (authenticated); 1034 } 1035 #endif /* GSSAPI */ 1036 1037 #ifdef KRB5 1038 int 1039 mm_auth_krb5(void *ctx, void *argp, char **userp, void *resp) 1040 { 1041 krb5_data *tkt, *reply; 1042 struct sshbuf *m; 1043 u_int success; 1044 int r; 1045 1046 debug3("%s entering", __func__); 1047 tkt = (krb5_data *) argp; 1048 reply = (krb5_data *) resp; 1049 1050 if ((m = sshbuf_new()) == NULL) 1051 fatal("%s: sshbuf_new failed", __func__); 1052 sshbuf_put_string(m, tkt->data, tkt->length); 1053 1054 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KRB5, m); 1055 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KRB5, m); 1056 1057 if ((r = sshbuf_get_u32(m, &success)) != 0) 1058 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1059 if (success) { 1060 size_t len; 1061 u_char *data; 1062 1063 if ((r = sshbuf_get_cstring(m, userp, NULL)) != 0 || 1064 (r = sshbuf_get_string(m, &data, &len)) != 0) 1065 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1066 reply->data = data; 1067 reply->length = len; 1068 } else { 1069 memset(reply, 0, sizeof(*reply)); 1070 *userp = NULL; 1071 } 1072 1073 sshbuf_free(m); 1074 return (success); 1075 } 1076 #endif 1077