1 /* $OpenBSD: monitor_wrap.c,v 1.138 2024/10/22 06:13:00 dtucker 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 #include <sys/wait.h> 33 34 #include <errno.h> 35 #include <pwd.h> 36 #include <signal.h> 37 #include <stdarg.h> 38 #include <stdio.h> 39 #include <string.h> 40 #include <unistd.h> 41 42 #ifdef WITH_OPENSSL 43 #include <openssl/bn.h> 44 #include <openssl/dh.h> 45 #include <openssl/evp.h> 46 #endif 47 48 #include "openbsd-compat/sys-queue.h" 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 "auth-pam.h" 65 #include "monitor.h" 66 #ifdef GSSAPI 67 #include "ssh-gss.h" 68 #endif 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 #include "monitor_wrap.h" 77 #include "srclimit.h" 78 79 #include "ssherr.h" 80 81 /* Imports */ 82 extern struct monitor *pmonitor; 83 extern struct sshbuf *loginmsg; 84 extern ServerOptions options; 85 86 void 87 mm_log_handler(LogLevel level, int forced, const char *msg, void *ctx) 88 { 89 struct sshbuf *log_msg; 90 struct monitor *mon = (struct monitor *)ctx; 91 int r; 92 size_t len; 93 94 if (mon->m_log_sendfd == -1) 95 fatal_f("no log channel"); 96 97 if ((log_msg = sshbuf_new()) == NULL) 98 fatal_f("sshbuf_new failed"); 99 100 if ((r = sshbuf_put_u32(log_msg, 0)) != 0 || /* length; filled below */ 101 (r = sshbuf_put_u32(log_msg, level)) != 0 || 102 (r = sshbuf_put_u32(log_msg, forced)) != 0 || 103 (r = sshbuf_put_cstring(log_msg, msg)) != 0) 104 fatal_fr(r, "assemble"); 105 if ((len = sshbuf_len(log_msg)) < 4 || len > 0xffffffff) 106 fatal_f("bad length %zu", len); 107 POKE_U32(sshbuf_mutable_ptr(log_msg), len - 4); 108 if (atomicio(vwrite, mon->m_log_sendfd, 109 sshbuf_mutable_ptr(log_msg), len) != len) 110 fatal_f("write: %s", strerror(errno)); 111 sshbuf_free(log_msg); 112 } 113 114 static void 115 mm_reap(void) 116 { 117 int status = -1; 118 119 if (!mm_is_monitor()) 120 return; 121 while (waitpid(pmonitor->m_pid, &status, 0) == -1) { 122 if (errno == EINTR) 123 continue; 124 pmonitor->m_pid = -1; 125 fatal_f("waitpid: %s", strerror(errno)); 126 } 127 if (WIFEXITED(status)) { 128 if (WEXITSTATUS(status) != 0) { 129 debug_f("preauth child exited with status %d", 130 WEXITSTATUS(status)); 131 cleanup_exit(255); 132 } 133 } else if (WIFSIGNALED(status)) { 134 error_f("preauth child terminated by signal %d", 135 WTERMSIG(status)); 136 cleanup_exit(signal_is_crash(WTERMSIG(status)) ? 137 EXIT_CHILD_CRASH : 255); 138 } else { 139 error_f("preauth child terminated abnormally (status=0x%x)", 140 status); 141 cleanup_exit(EXIT_CHILD_CRASH); 142 } 143 } 144 145 void 146 mm_request_send(int sock, enum monitor_reqtype type, struct sshbuf *m) 147 { 148 size_t mlen = sshbuf_len(m); 149 u_char buf[5]; 150 151 debug3_f("entering, type %d", type); 152 153 if (mlen >= 0xffffffff) 154 fatal_f("bad length %zu", mlen); 155 POKE_U32(buf, mlen + 1); 156 buf[4] = (u_char) type; /* 1st byte of payload is mesg-type */ 157 if (atomicio(vwrite, sock, buf, sizeof(buf)) != sizeof(buf) || 158 atomicio(vwrite, sock, sshbuf_mutable_ptr(m), mlen) != mlen) { 159 if (errno == EPIPE) { 160 debug3_f("monitor fd closed"); 161 mm_reap(); 162 cleanup_exit(255); 163 } 164 fatal_f("write: %s", strerror(errno)); 165 } 166 } 167 168 void 169 mm_request_receive(int sock, struct sshbuf *m) 170 { 171 u_char buf[4], *p = NULL; 172 u_int msg_len; 173 int oerrno, r; 174 175 debug3_f("entering"); 176 177 if (atomicio(read, sock, buf, sizeof(buf)) != sizeof(buf)) { 178 if (errno == EPIPE) { 179 debug3_f("monitor fd closed"); 180 mm_reap(); 181 cleanup_exit(255); 182 } 183 fatal_f("read: %s", strerror(errno)); 184 } 185 msg_len = PEEK_U32(buf); 186 if (msg_len > 256 * 1024) 187 fatal_f("read: bad msg_len %d", msg_len); 188 sshbuf_reset(m); 189 if ((r = sshbuf_reserve(m, msg_len, &p)) != 0) 190 fatal_fr(r, "reserve"); 191 if (atomicio(read, sock, p, msg_len) != msg_len) { 192 oerrno = errno; 193 error_f("read: %s", strerror(errno)); 194 if (oerrno == EPIPE) 195 mm_reap(); 196 cleanup_exit(255); 197 } 198 } 199 200 void 201 mm_request_receive_expect(int sock, enum monitor_reqtype type, struct sshbuf *m) 202 { 203 u_char rtype; 204 int r; 205 206 debug3_f("entering, type %d", type); 207 208 mm_request_receive(sock, m); 209 if ((r = sshbuf_get_u8(m, &rtype)) != 0) 210 fatal_fr(r, "parse"); 211 if (rtype != type) 212 fatal_f("read: rtype %d != type %d", rtype, type); 213 } 214 215 #ifdef WITH_OPENSSL 216 DH * 217 mm_choose_dh(int min, int nbits, int max) 218 { 219 BIGNUM *p, *g; 220 int r; 221 u_char success = 0; 222 struct sshbuf *m; 223 224 if ((m = sshbuf_new()) == NULL) 225 fatal_f("sshbuf_new failed"); 226 if ((r = sshbuf_put_u32(m, min)) != 0 || 227 (r = sshbuf_put_u32(m, nbits)) != 0 || 228 (r = sshbuf_put_u32(m, max)) != 0) 229 fatal_fr(r, "assemble"); 230 231 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_MODULI, m); 232 233 debug3_f("waiting for MONITOR_ANS_MODULI"); 234 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_MODULI, m); 235 236 if ((r = sshbuf_get_u8(m, &success)) != 0) 237 fatal_fr(r, "parse success"); 238 if (success == 0) 239 fatal_f("MONITOR_ANS_MODULI failed"); 240 241 if ((r = sshbuf_get_bignum2(m, &p)) != 0 || 242 (r = sshbuf_get_bignum2(m, &g)) != 0) 243 fatal_fr(r, "parse group"); 244 245 debug3_f("remaining %zu", sshbuf_len(m)); 246 sshbuf_free(m); 247 248 return (dh_new_group(g, p)); 249 } 250 #endif 251 252 int 253 mm_sshkey_sign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp, 254 const u_char *data, size_t datalen, const char *hostkey_alg, 255 const char *sk_provider, const char *sk_pin, u_int compat) 256 { 257 struct sshbuf *m; 258 int r; 259 260 debug3_f("entering"); 261 if ((m = sshbuf_new()) == NULL) 262 fatal_f("sshbuf_new failed"); 263 if ((r = sshkey_puts(key, m)) != 0 || 264 (r = sshbuf_put_string(m, data, datalen)) != 0 || 265 (r = sshbuf_put_cstring(m, hostkey_alg)) != 0 || 266 (r = sshbuf_put_u32(m, compat)) != 0) 267 fatal_fr(r, "assemble"); 268 269 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, m); 270 271 debug3_f("waiting for MONITOR_ANS_SIGN"); 272 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, m); 273 if ((r = sshbuf_get_string(m, sigp, lenp)) != 0) 274 fatal_fr(r, "parse"); 275 sshbuf_free(m); 276 debug3_f("%s signature len=%zu", hostkey_alg ? hostkey_alg : "(null)", 277 *lenp); 278 279 return (0); 280 } 281 282 void 283 mm_decode_activate_server_options(struct ssh *ssh, struct sshbuf *m) 284 { 285 const u_char *p; 286 size_t len; 287 u_int i; 288 ServerOptions *newopts; 289 int r; 290 291 if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0) 292 fatal_fr(r, "parse opts"); 293 if (len != sizeof(*newopts)) 294 fatal_f("option block size mismatch"); 295 newopts = xcalloc(sizeof(*newopts), 1); 296 memcpy(newopts, p, sizeof(*newopts)); 297 298 #define M_CP_STROPT(x) do { \ 299 if (newopts->x != NULL && \ 300 (r = sshbuf_get_cstring(m, &newopts->x, NULL)) != 0) \ 301 fatal_fr(r, "parse %s", #x); \ 302 } while (0) 303 #define M_CP_STRARRAYOPT(x, nx) do { \ 304 newopts->x = newopts->nx == 0 ? \ 305 NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \ 306 for (i = 0; i < newopts->nx; i++) { \ 307 if ((r = sshbuf_get_cstring(m, \ 308 &newopts->x[i], NULL)) != 0) \ 309 fatal_fr(r, "parse %s", #x); \ 310 } \ 311 } while (0) 312 /* See comment in servconf.h */ 313 COPY_MATCH_STRING_OPTS(); 314 #undef M_CP_STROPT 315 #undef M_CP_STRARRAYOPT 316 317 copy_set_server_options(&options, newopts, 1); 318 log_change_level(options.log_level); 319 log_verbose_reset(); 320 for (i = 0; i < options.num_log_verbose; i++) 321 log_verbose_add(options.log_verbose[i]); 322 free(newopts); 323 } 324 325 #define GETPW(b, id) \ 326 do { \ 327 if ((r = sshbuf_get_string_direct(b, &p, &len)) != 0) \ 328 fatal_fr(r, "parse pw %s", #id); \ 329 if (len != sizeof(pw->id)) \ 330 fatal_fr(r, "bad length for %s", #id); \ 331 memcpy(&pw->id, p, len); \ 332 } while (0) 333 334 struct passwd * 335 mm_getpwnamallow(struct ssh *ssh, const char *username) 336 { 337 struct sshbuf *m; 338 struct passwd *pw; 339 size_t len; 340 int r; 341 u_char ok; 342 const u_char *p; 343 344 debug3_f("entering"); 345 346 if ((m = sshbuf_new()) == NULL) 347 fatal_f("sshbuf_new failed"); 348 if ((r = sshbuf_put_cstring(m, username)) != 0) 349 fatal_fr(r, "assemble"); 350 351 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, m); 352 353 debug3_f("waiting for MONITOR_ANS_PWNAM"); 354 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, m); 355 356 if ((r = sshbuf_get_u8(m, &ok)) != 0) 357 fatal_fr(r, "parse success"); 358 if (ok == 0) { 359 pw = NULL; 360 goto out; 361 } 362 363 /* XXX don't like passing struct passwd like this */ 364 pw = xcalloc(sizeof(*pw), 1); 365 GETPW(m, pw_uid); 366 GETPW(m, pw_gid); 367 #ifdef HAVE_STRUCT_PASSWD_PW_CHANGE 368 GETPW(m, pw_change); 369 #endif 370 #ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE 371 GETPW(m, pw_expire); 372 #endif 373 if ((r = sshbuf_get_cstring(m, &pw->pw_name, NULL)) != 0 || 374 (r = sshbuf_get_cstring(m, &pw->pw_passwd, NULL)) != 0 || 375 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS 376 (r = sshbuf_get_cstring(m, &pw->pw_gecos, NULL)) != 0 || 377 #endif 378 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS 379 (r = sshbuf_get_cstring(m, &pw->pw_class, NULL)) != 0 || 380 #endif 381 (r = sshbuf_get_cstring(m, &pw->pw_dir, NULL)) != 0 || 382 (r = sshbuf_get_cstring(m, &pw->pw_shell, NULL)) != 0) 383 fatal_fr(r, "parse pw"); 384 385 out: 386 /* copy options block as a Match directive may have changed some */ 387 mm_decode_activate_server_options(ssh, m); 388 server_process_permitopen(ssh); 389 server_process_channel_timeouts(ssh); 390 kex_set_server_sig_algs(ssh, options.pubkey_accepted_algos); 391 sshbuf_free(m); 392 393 return (pw); 394 } 395 396 char * 397 mm_auth2_read_banner(void) 398 { 399 struct sshbuf *m; 400 char *banner; 401 int r; 402 403 debug3_f("entering"); 404 405 if ((m = sshbuf_new()) == NULL) 406 fatal_f("sshbuf_new failed"); 407 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, m); 408 sshbuf_reset(m); 409 410 mm_request_receive_expect(pmonitor->m_recvfd, 411 MONITOR_ANS_AUTH2_READ_BANNER, m); 412 if ((r = sshbuf_get_cstring(m, &banner, NULL)) != 0) 413 fatal_fr(r, "parse"); 414 sshbuf_free(m); 415 416 /* treat empty banner as missing banner */ 417 if (strlen(banner) == 0) { 418 free(banner); 419 banner = NULL; 420 } 421 return (banner); 422 } 423 424 /* Inform the privileged process about service and style */ 425 426 void 427 mm_inform_authserv(char *service, char *style) 428 { 429 struct sshbuf *m; 430 int r; 431 432 debug3_f("entering"); 433 434 if ((m = sshbuf_new()) == NULL) 435 fatal_f("sshbuf_new failed"); 436 if ((r = sshbuf_put_cstring(m, service)) != 0 || 437 (r = sshbuf_put_cstring(m, style ? style : "")) != 0) 438 fatal_fr(r, "assemble"); 439 440 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, m); 441 442 sshbuf_free(m); 443 } 444 445 /* Do the password authentication */ 446 int 447 mm_auth_password(struct ssh *ssh, char *password) 448 { 449 struct sshbuf *m; 450 int r, authenticated = 0; 451 #ifdef USE_PAM 452 u_int maxtries = 0; 453 #endif 454 455 debug3_f("entering"); 456 457 if ((m = sshbuf_new()) == NULL) 458 fatal_f("sshbuf_new failed"); 459 if ((r = sshbuf_put_cstring(m, password)) != 0) 460 fatal_fr(r, "assemble"); 461 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, m); 462 463 debug3_f("waiting for MONITOR_ANS_AUTHPASSWORD"); 464 mm_request_receive_expect(pmonitor->m_recvfd, 465 MONITOR_ANS_AUTHPASSWORD, m); 466 467 if ((r = sshbuf_get_u32(m, &authenticated)) != 0) 468 fatal_fr(r, "parse"); 469 #ifdef USE_PAM 470 if ((r = sshbuf_get_u32(m, &maxtries)) != 0) 471 fatal_fr(r, "parse PAM"); 472 if (maxtries > INT_MAX) 473 fatal_fr(r, "bad maxtries"); 474 sshpam_set_maxtries_reached(maxtries); 475 #endif 476 477 sshbuf_free(m); 478 479 debug3_f("user %sauthenticated", authenticated ? "" : "not "); 480 return (authenticated); 481 } 482 483 int 484 mm_user_key_allowed(struct ssh *ssh, struct passwd *pw, struct sshkey *key, 485 int pubkey_auth_attempt, struct sshauthopt **authoptp) 486 { 487 return (mm_key_allowed(MM_USERKEY, NULL, NULL, key, 488 pubkey_auth_attempt, authoptp)); 489 } 490 491 int 492 mm_hostbased_key_allowed(struct ssh *ssh, struct passwd *pw, 493 const char *user, const char *host, struct sshkey *key) 494 { 495 return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0, NULL)); 496 } 497 498 int 499 mm_key_allowed(enum mm_keytype type, const char *user, const char *host, 500 struct sshkey *key, int pubkey_auth_attempt, struct sshauthopt **authoptp) 501 { 502 struct sshbuf *m; 503 int r, allowed = 0; 504 struct sshauthopt *opts = NULL; 505 506 debug3_f("entering"); 507 508 if (authoptp != NULL) 509 *authoptp = NULL; 510 511 if ((m = sshbuf_new()) == NULL) 512 fatal_f("sshbuf_new failed"); 513 if ((r = sshbuf_put_u32(m, type)) != 0 || 514 (r = sshbuf_put_cstring(m, user ? user : "")) != 0 || 515 (r = sshbuf_put_cstring(m, host ? host : "")) != 0 || 516 (r = sshkey_puts(key, m)) != 0 || 517 (r = sshbuf_put_u32(m, pubkey_auth_attempt)) != 0) 518 fatal_fr(r, "assemble"); 519 520 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, m); 521 522 debug3_f("waiting for MONITOR_ANS_KEYALLOWED"); 523 mm_request_receive_expect(pmonitor->m_recvfd, 524 MONITOR_ANS_KEYALLOWED, m); 525 526 if ((r = sshbuf_get_u32(m, &allowed)) != 0) 527 fatal_fr(r, "parse"); 528 if (allowed && type == MM_USERKEY && 529 (r = sshauthopt_deserialise(m, &opts)) != 0) 530 fatal_fr(r, "sshauthopt_deserialise"); 531 sshbuf_free(m); 532 533 if (authoptp != NULL) { 534 *authoptp = opts; 535 opts = NULL; 536 } 537 sshauthopt_free(opts); 538 539 return allowed; 540 } 541 542 /* 543 * This key verify needs to send the key type along, because the 544 * privileged parent makes the decision if the key is allowed 545 * for authentication. 546 */ 547 548 int 549 mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen, 550 const u_char *data, size_t datalen, const char *sigalg, u_int compat, 551 struct sshkey_sig_details **sig_detailsp) 552 { 553 struct sshbuf *m; 554 u_int encoded_ret = 0; 555 int r; 556 u_char sig_details_present, flags; 557 u_int counter; 558 559 debug3_f("entering"); 560 561 if (sig_detailsp != NULL) 562 *sig_detailsp = NULL; 563 if ((m = sshbuf_new()) == NULL) 564 fatal_f("sshbuf_new failed"); 565 if ((r = sshkey_puts(key, m)) != 0 || 566 (r = sshbuf_put_string(m, sig, siglen)) != 0 || 567 (r = sshbuf_put_string(m, data, datalen)) != 0 || 568 (r = sshbuf_put_cstring(m, sigalg == NULL ? "" : sigalg)) != 0) 569 fatal_fr(r, "assemble"); 570 571 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, m); 572 573 debug3_f("waiting for MONITOR_ANS_KEYVERIFY"); 574 mm_request_receive_expect(pmonitor->m_recvfd, 575 MONITOR_ANS_KEYVERIFY, m); 576 577 if ((r = sshbuf_get_u32(m, &encoded_ret)) != 0 || 578 (r = sshbuf_get_u8(m, &sig_details_present)) != 0) 579 fatal_fr(r, "parse"); 580 if (sig_details_present && encoded_ret == 0) { 581 if ((r = sshbuf_get_u32(m, &counter)) != 0 || 582 (r = sshbuf_get_u8(m, &flags)) != 0) 583 fatal_fr(r, "parse sig_details"); 584 if (sig_detailsp != NULL) { 585 *sig_detailsp = xcalloc(1, sizeof(**sig_detailsp)); 586 (*sig_detailsp)->sk_counter = counter; 587 (*sig_detailsp)->sk_flags = flags; 588 } 589 } 590 591 sshbuf_free(m); 592 593 if (encoded_ret != 0) 594 return SSH_ERR_SIGNATURE_INVALID; 595 return 0; 596 } 597 598 void 599 mm_send_keystate(struct ssh *ssh, struct monitor *monitor) 600 { 601 struct sshbuf *m; 602 int r; 603 604 if ((m = sshbuf_new()) == NULL) 605 fatal_f("sshbuf_new failed"); 606 if ((r = ssh_packet_get_state(ssh, m)) != 0) 607 fatal_fr(r, "ssh_packet_get_state"); 608 mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m); 609 debug3_f("Finished sending state"); 610 sshbuf_free(m); 611 } 612 613 int 614 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen) 615 { 616 struct sshbuf *m; 617 char *p, *msg; 618 int success = 0, tmp1 = -1, tmp2 = -1, r; 619 620 /* Kludge: ensure there are fds free to receive the pty/tty */ 621 if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 || 622 (tmp2 = dup(pmonitor->m_recvfd)) == -1) { 623 error_f("cannot allocate fds for pty"); 624 if (tmp1 >= 0) 625 close(tmp1); 626 return 0; 627 } 628 close(tmp1); 629 close(tmp2); 630 631 if ((m = sshbuf_new()) == NULL) 632 fatal_f("sshbuf_new failed"); 633 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, m); 634 635 debug3_f("waiting for MONITOR_ANS_PTY"); 636 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, m); 637 638 if ((r = sshbuf_get_u32(m, &success)) != 0) 639 fatal_fr(r, "parse success"); 640 if (success == 0) { 641 debug3_f("pty alloc failed"); 642 sshbuf_free(m); 643 return (0); 644 } 645 if ((r = sshbuf_get_cstring(m, &p, NULL)) != 0 || 646 (r = sshbuf_get_cstring(m, &msg, NULL)) != 0) 647 fatal_fr(r, "parse"); 648 sshbuf_free(m); 649 650 strlcpy(namebuf, p, namebuflen); /* Possible truncation */ 651 free(p); 652 653 if ((r = sshbuf_put(loginmsg, msg, strlen(msg))) != 0) 654 fatal_fr(r, "put loginmsg"); 655 free(msg); 656 657 if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 || 658 (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1) 659 fatal_f("receive fds failed"); 660 661 /* Success */ 662 return (1); 663 } 664 665 void 666 mm_session_pty_cleanup2(Session *s) 667 { 668 struct sshbuf *m; 669 int r; 670 671 if (s->ttyfd == -1) 672 return; 673 if ((m = sshbuf_new()) == NULL) 674 fatal_f("sshbuf_new failed"); 675 if ((r = sshbuf_put_cstring(m, s->tty)) != 0) 676 fatal_fr(r, "assmble"); 677 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, m); 678 sshbuf_free(m); 679 680 /* closed dup'ed master */ 681 if (s->ptymaster != -1 && close(s->ptymaster) == -1) 682 error("close(s->ptymaster/%d): %s", 683 s->ptymaster, strerror(errno)); 684 685 /* unlink pty from session */ 686 s->ttyfd = -1; 687 } 688 689 #ifdef USE_PAM 690 void 691 mm_start_pam(struct ssh *ssh) 692 { 693 struct sshbuf *m; 694 695 debug3("%s entering", __func__); 696 if (!options.use_pam) 697 fatal("UsePAM=no, but ended up in %s anyway", __func__); 698 if ((m = sshbuf_new()) == NULL) 699 fatal("%s: sshbuf_new failed", __func__); 700 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, m); 701 702 sshbuf_free(m); 703 } 704 705 u_int 706 mm_do_pam_account(void) 707 { 708 struct sshbuf *m; 709 u_int ret; 710 char *msg; 711 size_t msglen; 712 int r; 713 714 debug3("%s entering", __func__); 715 if (!options.use_pam) 716 fatal("UsePAM=no, but ended up in %s anyway", __func__); 717 718 if ((m = sshbuf_new()) == NULL) 719 fatal("%s: sshbuf_new failed", __func__); 720 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, m); 721 722 mm_request_receive_expect(pmonitor->m_recvfd, 723 MONITOR_ANS_PAM_ACCOUNT, m); 724 if ((r = sshbuf_get_u32(m, &ret)) != 0 || 725 (r = sshbuf_get_cstring(m, &msg, &msglen)) != 0 || 726 (r = sshbuf_put(loginmsg, msg, msglen)) != 0) 727 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 728 729 free(msg); 730 sshbuf_free(m); 731 732 debug3("%s returning %d", __func__, ret); 733 734 return (ret); 735 } 736 737 void * 738 mm_sshpam_init_ctx(Authctxt *authctxt) 739 { 740 struct sshbuf *m; 741 int r, success; 742 743 debug3("%s", __func__); 744 if ((m = sshbuf_new()) == NULL) 745 fatal("%s: sshbuf_new failed", __func__); 746 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, m); 747 debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__); 748 mm_request_receive_expect(pmonitor->m_recvfd, 749 MONITOR_ANS_PAM_INIT_CTX, m); 750 if ((r = sshbuf_get_u32(m, &success)) != 0) 751 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 752 if (success == 0) { 753 debug3("%s: pam_init_ctx failed", __func__); 754 sshbuf_free(m); 755 return (NULL); 756 } 757 sshbuf_free(m); 758 return (authctxt); 759 } 760 761 int 762 mm_sshpam_query(void *ctx, char **name, char **info, 763 u_int *num, char ***prompts, u_int **echo_on) 764 { 765 struct sshbuf *m; 766 u_int i, n; 767 int r, ret; 768 769 debug3("%s", __func__); 770 if ((m = sshbuf_new()) == NULL) 771 fatal("%s: sshbuf_new failed", __func__); 772 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_QUERY, m); 773 debug3("%s: waiting for MONITOR_ANS_PAM_QUERY", __func__); 774 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_QUERY, m); 775 if ((r = sshbuf_get_u32(m, &ret)) != 0 || 776 (r = sshbuf_get_cstring(m, name, NULL)) != 0 || 777 (r = sshbuf_get_cstring(m, info, NULL)) != 0 || 778 (r = sshbuf_get_u32(m, &n)) != 0 || 779 (r = sshbuf_get_u32(m, num)) != 0) 780 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 781 debug3("%s: pam_query returned %d", __func__, ret); 782 sshpam_set_maxtries_reached(n); 783 if (*num > PAM_MAX_NUM_MSG) 784 fatal("%s: received %u PAM messages, expected <= %u", 785 __func__, *num, PAM_MAX_NUM_MSG); 786 *prompts = xcalloc((*num + 1), sizeof(char *)); 787 *echo_on = xcalloc((*num + 1), sizeof(u_int)); 788 for (i = 0; i < *num; ++i) { 789 if ((r = sshbuf_get_cstring(m, &((*prompts)[i]), NULL)) != 0 || 790 (r = sshbuf_get_u32(m, &((*echo_on)[i]))) != 0) 791 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 792 } 793 sshbuf_free(m); 794 return (ret); 795 } 796 797 int 798 mm_sshpam_respond(void *ctx, u_int num, char **resp) 799 { 800 struct sshbuf *m; 801 u_int n, i; 802 int r, ret; 803 804 debug3("%s", __func__); 805 if ((m = sshbuf_new()) == NULL) 806 fatal("%s: sshbuf_new failed", __func__); 807 if ((r = sshbuf_put_u32(m, num)) != 0) 808 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 809 for (i = 0; i < num; ++i) { 810 if ((r = sshbuf_put_cstring(m, resp[i])) != 0) 811 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 812 } 813 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, m); 814 debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__); 815 mm_request_receive_expect(pmonitor->m_recvfd, 816 MONITOR_ANS_PAM_RESPOND, m); 817 if ((r = sshbuf_get_u32(m, &n)) != 0) 818 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 819 ret = (int)n; /* XXX */ 820 debug3("%s: pam_respond returned %d", __func__, ret); 821 sshbuf_free(m); 822 return (ret); 823 } 824 825 void 826 mm_sshpam_free_ctx(void *ctxtp) 827 { 828 struct sshbuf *m; 829 830 debug3("%s", __func__); 831 if ((m = sshbuf_new()) == NULL) 832 fatal("%s: sshbuf_new failed", __func__); 833 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_FREE_CTX, m); 834 debug3("%s: waiting for MONITOR_ANS_PAM_FREE_CTX", __func__); 835 mm_request_receive_expect(pmonitor->m_recvfd, 836 MONITOR_ANS_PAM_FREE_CTX, m); 837 sshbuf_free(m); 838 } 839 #endif /* USE_PAM */ 840 841 /* Request process termination */ 842 843 void 844 mm_terminate(void) 845 { 846 struct sshbuf *m; 847 848 if ((m = sshbuf_new()) == NULL) 849 fatal_f("sshbuf_new failed"); 850 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, m); 851 sshbuf_free(m); 852 } 853 854 /* Request state information */ 855 856 void 857 mm_get_state(struct ssh *ssh, struct include_list *includes, 858 struct sshbuf *conf, struct sshbuf **confdatap, 859 uint64_t *timing_secretp, 860 struct sshbuf **hostkeysp, struct sshbuf **keystatep, 861 u_char **pw_namep, 862 struct sshbuf **authinfop, struct sshbuf **auth_optsp) 863 { 864 struct sshbuf *m, *inc; 865 u_char *cp; 866 size_t len; 867 int r; 868 struct include_item *item; 869 870 debug3_f("entering"); 871 872 if ((m = sshbuf_new()) == NULL || (inc = sshbuf_new()) == NULL) 873 fatal_f("sshbuf_new failed"); 874 875 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_STATE, m); 876 877 debug3_f("waiting for MONITOR_ANS_STATE"); 878 mm_request_receive_expect(pmonitor->m_recvfd, 879 MONITOR_ANS_STATE, m); 880 881 if ((r = sshbuf_get_string(m, &cp, &len)) != 0 || 882 (r = sshbuf_get_u64(m, timing_secretp)) != 0 || 883 (r = sshbuf_froms(m, hostkeysp)) != 0 || 884 (r = sshbuf_get_stringb(m, ssh->kex->server_version)) != 0 || 885 (r = sshbuf_get_stringb(m, ssh->kex->client_version)) != 0 || 886 (r = sshbuf_get_stringb(m, inc)) != 0) 887 fatal_fr(r, "parse config"); 888 889 /* postauth */ 890 if (confdatap) { 891 if ((r = sshbuf_froms(m, confdatap)) != 0 || 892 (r = sshbuf_froms(m, keystatep)) != 0 || 893 (r = sshbuf_get_string(m, pw_namep, NULL)) != 0 || 894 (r = sshbuf_froms(m, authinfop)) != 0 || 895 (r = sshbuf_froms(m, auth_optsp)) != 0) 896 fatal_fr(r, "parse config postauth"); 897 } 898 899 if (conf != NULL && (r = sshbuf_put(conf, cp, len))) 900 fatal_fr(r, "sshbuf_put"); 901 902 while (sshbuf_len(inc) != 0) { 903 item = xcalloc(1, sizeof(*item)); 904 if ((item->contents = sshbuf_new()) == NULL) 905 fatal_f("sshbuf_new failed"); 906 if ((r = sshbuf_get_cstring(inc, &item->selector, NULL)) != 0 || 907 (r = sshbuf_get_cstring(inc, &item->filename, NULL)) != 0 || 908 (r = sshbuf_get_stringb(inc, item->contents)) != 0) 909 fatal_fr(r, "parse includes"); 910 TAILQ_INSERT_TAIL(includes, item, entry); 911 } 912 913 free(cp); 914 sshbuf_free(m); 915 sshbuf_free(inc); 916 917 debug3_f("done"); 918 } 919 920 static void 921 mm_chall_setup(char **name, char **infotxt, u_int *numprompts, 922 char ***prompts, u_int **echo_on) 923 { 924 *name = xstrdup(""); 925 *infotxt = xstrdup(""); 926 *numprompts = 1; 927 *prompts = xcalloc(*numprompts, sizeof(char *)); 928 *echo_on = xcalloc(*numprompts, sizeof(u_int)); 929 (*echo_on)[0] = 0; 930 } 931 932 int 933 mm_bsdauth_query(void *ctx, char **name, char **infotxt, 934 u_int *numprompts, char ***prompts, u_int **echo_on) 935 { 936 struct sshbuf *m; 937 u_int success; 938 char *challenge; 939 int r; 940 941 debug3_f("entering"); 942 943 if ((m = sshbuf_new()) == NULL) 944 fatal_f("sshbuf_new failed"); 945 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, m); 946 947 mm_request_receive_expect(pmonitor->m_recvfd, 948 MONITOR_ANS_BSDAUTHQUERY, m); 949 if ((r = sshbuf_get_u32(m, &success)) != 0) 950 fatal_fr(r, "parse success"); 951 if (success == 0) { 952 debug3_f("no challenge"); 953 sshbuf_free(m); 954 return (-1); 955 } 956 957 /* Get the challenge, and format the response */ 958 if ((r = sshbuf_get_cstring(m, &challenge, NULL)) != 0) 959 fatal_fr(r, "parse challenge"); 960 sshbuf_free(m); 961 962 mm_chall_setup(name, infotxt, numprompts, prompts, echo_on); 963 (*prompts)[0] = challenge; 964 965 debug3_f("received challenge: %s", challenge); 966 967 return (0); 968 } 969 970 int 971 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses) 972 { 973 struct sshbuf *m; 974 int r, authok; 975 976 debug3_f("entering"); 977 if (numresponses != 1) 978 return (-1); 979 980 if ((m = sshbuf_new()) == NULL) 981 fatal_f("sshbuf_new failed"); 982 if ((r = sshbuf_put_cstring(m, responses[0])) != 0) 983 fatal_fr(r, "assemble"); 984 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, m); 985 986 mm_request_receive_expect(pmonitor->m_recvfd, 987 MONITOR_ANS_BSDAUTHRESPOND, m); 988 989 if ((r = sshbuf_get_u32(m, &authok)) != 0) 990 fatal_fr(r, "parse"); 991 sshbuf_free(m); 992 993 return ((authok == 0) ? -1 : 0); 994 } 995 996 #ifdef SSH_AUDIT_EVENTS 997 void 998 mm_audit_event(struct ssh *ssh, ssh_audit_event_t event) 999 { 1000 struct sshbuf *m; 1001 int r; 1002 1003 debug3("%s entering", __func__); 1004 1005 if ((m = sshbuf_new()) == NULL) 1006 fatal("%s: sshbuf_new failed", __func__); 1007 if ((r = sshbuf_put_u32(m, event)) != 0) 1008 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1009 1010 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_EVENT, m); 1011 sshbuf_free(m); 1012 } 1013 1014 void 1015 mm_audit_run_command(const char *command) 1016 { 1017 struct sshbuf *m; 1018 int r; 1019 1020 debug3("%s entering command %s", __func__, command); 1021 1022 if ((m = sshbuf_new()) == NULL) 1023 fatal("%s: sshbuf_new failed", __func__); 1024 if ((r = sshbuf_put_cstring(m, command)) != 0) 1025 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1026 1027 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_COMMAND, m); 1028 sshbuf_free(m); 1029 } 1030 #endif /* SSH_AUDIT_EVENTS */ 1031 1032 #ifdef GSSAPI 1033 OM_uint32 1034 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid) 1035 { 1036 struct sshbuf *m; 1037 OM_uint32 major; 1038 int r; 1039 1040 /* Client doesn't get to see the context */ 1041 *ctx = NULL; 1042 1043 if ((m = sshbuf_new()) == NULL) 1044 fatal_f("sshbuf_new failed"); 1045 if ((r = sshbuf_put_string(m, goid->elements, goid->length)) != 0) 1046 fatal_fr(r, "assemble"); 1047 1048 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, m); 1049 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, m); 1050 1051 if ((r = sshbuf_get_u32(m, &major)) != 0) 1052 fatal_fr(r, "parse"); 1053 1054 sshbuf_free(m); 1055 return (major); 1056 } 1057 1058 OM_uint32 1059 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in, 1060 gss_buffer_desc *out, OM_uint32 *flagsp) 1061 { 1062 struct sshbuf *m; 1063 OM_uint32 major; 1064 u_int flags; 1065 int r; 1066 1067 if ((m = sshbuf_new()) == NULL) 1068 fatal_f("sshbuf_new failed"); 1069 if ((r = sshbuf_put_string(m, in->value, in->length)) != 0) 1070 fatal_fr(r, "assemble"); 1071 1072 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, m); 1073 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, m); 1074 1075 if ((r = sshbuf_get_u32(m, &major)) != 0 || 1076 (r = ssh_gssapi_get_buffer_desc(m, out)) != 0) 1077 fatal_fr(r, "parse"); 1078 if (flagsp != NULL) { 1079 if ((r = sshbuf_get_u32(m, &flags)) != 0) 1080 fatal_fr(r, "parse flags"); 1081 *flagsp = flags; 1082 } 1083 1084 sshbuf_free(m); 1085 1086 return (major); 1087 } 1088 1089 OM_uint32 1090 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) 1091 { 1092 struct sshbuf *m; 1093 OM_uint32 major; 1094 int r; 1095 1096 if ((m = sshbuf_new()) == NULL) 1097 fatal_f("sshbuf_new failed"); 1098 if ((r = sshbuf_put_string(m, gssbuf->value, gssbuf->length)) != 0 || 1099 (r = sshbuf_put_string(m, gssmic->value, gssmic->length)) != 0) 1100 fatal_fr(r, "assemble"); 1101 1102 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, m); 1103 mm_request_receive_expect(pmonitor->m_recvfd, 1104 MONITOR_ANS_GSSCHECKMIC, m); 1105 1106 if ((r = sshbuf_get_u32(m, &major)) != 0) 1107 fatal_fr(r, "parse"); 1108 sshbuf_free(m); 1109 return(major); 1110 } 1111 1112 int 1113 mm_ssh_gssapi_userok(char *user) 1114 { 1115 struct sshbuf *m; 1116 int r, authenticated = 0; 1117 1118 if ((m = sshbuf_new()) == NULL) 1119 fatal_f("sshbuf_new failed"); 1120 1121 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, m); 1122 mm_request_receive_expect(pmonitor->m_recvfd, 1123 MONITOR_ANS_GSSUSEROK, m); 1124 1125 if ((r = sshbuf_get_u32(m, &authenticated)) != 0) 1126 fatal_fr(r, "parse"); 1127 1128 sshbuf_free(m); 1129 debug3_f("user %sauthenticated", authenticated ? "" : "not "); 1130 return (authenticated); 1131 } 1132 #endif /* GSSAPI */ 1133 1134 /* 1135 * Inform channels layer of permitopen options for a single forwarding 1136 * direction (local/remote). 1137 */ 1138 static void 1139 server_process_permitopen_list(struct ssh *ssh, int listen, 1140 char **opens, u_int num_opens) 1141 { 1142 u_int i; 1143 int port; 1144 char *host, *arg, *oarg; 1145 int where = listen ? FORWARD_REMOTE : FORWARD_LOCAL; 1146 const char *what = listen ? "permitlisten" : "permitopen"; 1147 1148 channel_clear_permission(ssh, FORWARD_ADM, where); 1149 if (num_opens == 0) 1150 return; /* permit any */ 1151 1152 /* handle keywords: "any" / "none" */ 1153 if (num_opens == 1 && strcmp(opens[0], "any") == 0) 1154 return; 1155 if (num_opens == 1 && strcmp(opens[0], "none") == 0) { 1156 channel_disable_admin(ssh, where); 1157 return; 1158 } 1159 /* Otherwise treat it as a list of permitted host:port */ 1160 for (i = 0; i < num_opens; i++) { 1161 oarg = arg = xstrdup(opens[i]); 1162 host = hpdelim(&arg); 1163 if (host == NULL) 1164 fatal_f("missing host in %s", what); 1165 host = cleanhostname(host); 1166 if (arg == NULL || ((port = permitopen_port(arg)) < 0)) 1167 fatal_f("bad port number in %s", what); 1168 /* Send it to channels layer */ 1169 channel_add_permission(ssh, FORWARD_ADM, 1170 where, host, port); 1171 free(oarg); 1172 } 1173 } 1174 1175 /* 1176 * Inform channels layer of permitopen options from configuration. 1177 */ 1178 void 1179 server_process_permitopen(struct ssh *ssh) 1180 { 1181 server_process_permitopen_list(ssh, 0, 1182 options.permitted_opens, options.num_permitted_opens); 1183 server_process_permitopen_list(ssh, 1, 1184 options.permitted_listens, options.num_permitted_listens); 1185 } 1186 1187 void 1188 server_process_channel_timeouts(struct ssh *ssh) 1189 { 1190 u_int i, secs; 1191 char *type; 1192 1193 debug3_f("setting %u timeouts", options.num_channel_timeouts); 1194 channel_clear_timeouts(ssh); 1195 for (i = 0; i < options.num_channel_timeouts; i++) { 1196 if (parse_pattern_interval(options.channel_timeouts[i], 1197 &type, &secs) != 0) { 1198 fatal_f("internal error: bad timeout %s", 1199 options.channel_timeouts[i]); 1200 } 1201 channel_add_timeout(ssh, type, secs); 1202 free(type); 1203 } 1204 } 1205 1206 struct connection_info * 1207 server_get_connection_info(struct ssh *ssh, int populate, int use_dns) 1208 { 1209 static struct connection_info ci; 1210 1211 if (ssh == NULL || !populate) 1212 return &ci; 1213 ci.host = use_dns ? ssh_remote_hostname(ssh) : ssh_remote_ipaddr(ssh); 1214 ci.address = ssh_remote_ipaddr(ssh); 1215 ci.laddress = ssh_local_ipaddr(ssh); 1216 ci.lport = ssh_local_port(ssh); 1217 ci.rdomain = ssh_packet_rdomain_in(ssh); 1218 return &ci; 1219 } 1220 1221