1 /* $OpenBSD: monitor_wrap.c,v 1.128 2023/03/31 00:44:29 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 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, int forced, 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_f("no log channel"); 94 95 if ((log_msg = sshbuf_new()) == NULL) 96 fatal_f("sshbuf_new failed"); 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_u32(log_msg, forced)) != 0 || 101 (r = sshbuf_put_cstring(log_msg, msg)) != 0) 102 fatal_fr(r, "assemble"); 103 if ((len = sshbuf_len(log_msg)) < 4 || len > 0xffffffff) 104 fatal_f("bad length %zu", len); 105 POKE_U32(sshbuf_mutable_ptr(log_msg), len - 4); 106 if (atomicio(vwrite, mon->m_log_sendfd, 107 sshbuf_mutable_ptr(log_msg), len) != len) 108 fatal_f("write: %s", strerror(errno)); 109 sshbuf_free(log_msg); 110 } 111 112 int 113 mm_is_monitor(void) 114 { 115 /* 116 * m_pid is only set in the privileged part, and 117 * points to the unprivileged child. 118 */ 119 return (pmonitor && pmonitor->m_pid > 0); 120 } 121 122 void 123 mm_request_send(int sock, enum monitor_reqtype type, struct sshbuf *m) 124 { 125 size_t mlen = sshbuf_len(m); 126 u_char buf[5]; 127 128 debug3_f("entering, type %d", type); 129 130 if (mlen >= 0xffffffff) 131 fatal_f("bad length %zu", mlen); 132 POKE_U32(buf, mlen + 1); 133 buf[4] = (u_char) type; /* 1st byte of payload is mesg-type */ 134 if (atomicio(vwrite, sock, buf, sizeof(buf)) != sizeof(buf)) 135 fatal_f("write: %s", strerror(errno)); 136 if (atomicio(vwrite, sock, sshbuf_mutable_ptr(m), mlen) != mlen) 137 fatal_f("write: %s", strerror(errno)); 138 } 139 140 void 141 mm_request_receive(int sock, struct sshbuf *m) 142 { 143 u_char buf[4], *p = NULL; 144 u_int msg_len; 145 int r; 146 147 debug3_f("entering"); 148 149 if (atomicio(read, sock, buf, sizeof(buf)) != sizeof(buf)) { 150 if (errno == EPIPE) 151 cleanup_exit(255); 152 fatal_f("read: %s", strerror(errno)); 153 } 154 msg_len = PEEK_U32(buf); 155 if (msg_len > 256 * 1024) 156 fatal_f("read: bad msg_len %d", msg_len); 157 sshbuf_reset(m); 158 if ((r = sshbuf_reserve(m, msg_len, &p)) != 0) 159 fatal_fr(r, "reserve"); 160 if (atomicio(read, sock, p, msg_len) != msg_len) 161 fatal_f("read: %s", strerror(errno)); 162 } 163 164 void 165 mm_request_receive_expect(int sock, enum monitor_reqtype type, struct sshbuf *m) 166 { 167 u_char rtype; 168 int r; 169 170 debug3_f("entering, type %d", type); 171 172 mm_request_receive(sock, m); 173 if ((r = sshbuf_get_u8(m, &rtype)) != 0) 174 fatal_fr(r, "parse"); 175 if (rtype != type) 176 fatal_f("read: rtype %d != type %d", 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_f("sshbuf_new failed"); 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_fr(r, "assemble"); 194 195 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_MODULI, m); 196 197 debug3_f("waiting for MONITOR_ANS_MODULI"); 198 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_MODULI, m); 199 200 if ((r = sshbuf_get_u8(m, &success)) != 0) 201 fatal_fr(r, "parse success"); 202 if (success == 0) 203 fatal_f("MONITOR_ANS_MODULI failed"); 204 205 if ((r = sshbuf_get_bignum2(m, &p)) != 0 || 206 (r = sshbuf_get_bignum2(m, &g)) != 0) 207 fatal_fr(r, "parse group"); 208 209 debug3_f("remaining %zu", 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, 219 const char *sk_provider, const char *sk_pin, u_int compat) 220 { 221 struct kex *kex = *pmonitor->m_pkex; 222 struct sshbuf *m; 223 u_int ndx = kex->host_key_index(key, 0, ssh); 224 int r; 225 226 debug3_f("entering"); 227 if ((m = sshbuf_new()) == NULL) 228 fatal_f("sshbuf_new failed"); 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_fr(r, "assemble"); 234 235 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, m); 236 237 debug3_f("waiting for MONITOR_ANS_SIGN"); 238 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, m); 239 if ((r = sshbuf_get_string(m, sigp, lenp)) != 0) 240 fatal_fr(r, "parse"); 241 sshbuf_free(m); 242 243 return (0); 244 } 245 246 #define GETPW(b, id) \ 247 do { \ 248 if ((r = sshbuf_get_string_direct(b, &p, &len)) != 0) \ 249 fatal_fr(r, "parse pw %s", #id); \ 250 if (len != sizeof(pw->id)) \ 251 fatal_fr(r, "bad length for %s", #id); \ 252 memcpy(&pw->id, p, len); \ 253 } while (0) 254 255 struct passwd * 256 mm_getpwnamallow(struct ssh *ssh, const char *username) 257 { 258 struct sshbuf *m; 259 struct passwd *pw; 260 size_t len; 261 u_int i; 262 ServerOptions *newopts; 263 int r; 264 u_char ok; 265 const u_char *p; 266 267 debug3_f("entering"); 268 269 if ((m = sshbuf_new()) == NULL) 270 fatal_f("sshbuf_new failed"); 271 if ((r = sshbuf_put_cstring(m, username)) != 0) 272 fatal_fr(r, "assemble"); 273 274 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, m); 275 276 debug3_f("waiting for MONITOR_ANS_PWNAM"); 277 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, m); 278 279 if ((r = sshbuf_get_u8(m, &ok)) != 0) 280 fatal_fr(r, "parse success"); 281 if (ok == 0) { 282 pw = NULL; 283 goto out; 284 } 285 286 /* XXX don't like passing struct passwd like this */ 287 pw = xcalloc(sizeof(*pw), 1); 288 GETPW(m, pw_uid); 289 GETPW(m, pw_gid); 290 #ifdef HAVE_STRUCT_PASSWD_PW_CHANGE 291 GETPW(m, pw_change); 292 #endif 293 #ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE 294 GETPW(m, pw_expire); 295 #endif 296 if ((r = sshbuf_get_cstring(m, &pw->pw_name, NULL)) != 0 || 297 (r = sshbuf_get_cstring(m, &pw->pw_passwd, NULL)) != 0 || 298 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS 299 (r = sshbuf_get_cstring(m, &pw->pw_gecos, NULL)) != 0 || 300 #endif 301 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS 302 (r = sshbuf_get_cstring(m, &pw->pw_class, NULL)) != 0 || 303 #endif 304 (r = sshbuf_get_cstring(m, &pw->pw_dir, NULL)) != 0 || 305 (r = sshbuf_get_cstring(m, &pw->pw_shell, NULL)) != 0) 306 fatal_fr(r, "parse pw"); 307 308 out: 309 /* copy options block as a Match directive may have changed some */ 310 if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0) 311 fatal_fr(r, "parse opts"); 312 if (len != sizeof(*newopts)) 313 fatal_f("option block size mismatch"); 314 newopts = xcalloc(sizeof(*newopts), 1); 315 memcpy(newopts, p, sizeof(*newopts)); 316 317 #define M_CP_STROPT(x) do { \ 318 if (newopts->x != NULL && \ 319 (r = sshbuf_get_cstring(m, &newopts->x, NULL)) != 0) \ 320 fatal_fr(r, "parse %s", #x); \ 321 } while (0) 322 #define M_CP_STRARRAYOPT(x, nx) do { \ 323 newopts->x = newopts->nx == 0 ? \ 324 NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \ 325 for (i = 0; i < newopts->nx; i++) { \ 326 if ((r = sshbuf_get_cstring(m, \ 327 &newopts->x[i], NULL)) != 0) \ 328 fatal_fr(r, "parse %s", #x); \ 329 } \ 330 } while (0) 331 /* See comment in servconf.h */ 332 COPY_MATCH_STRING_OPTS(); 333 #undef M_CP_STROPT 334 #undef M_CP_STRARRAYOPT 335 336 copy_set_server_options(&options, newopts, 1); 337 log_change_level(options.log_level); 338 log_verbose_reset(); 339 for (i = 0; i < options.num_log_verbose; i++) 340 log_verbose_add(options.log_verbose[i]); 341 process_permitopen(ssh, &options); 342 process_channel_timeouts(ssh, &options); 343 free(newopts); 344 345 sshbuf_free(m); 346 347 return (pw); 348 } 349 350 char * 351 mm_auth2_read_banner(void) 352 { 353 struct sshbuf *m; 354 char *banner; 355 int r; 356 357 debug3_f("entering"); 358 359 if ((m = sshbuf_new()) == NULL) 360 fatal_f("sshbuf_new failed"); 361 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, m); 362 sshbuf_reset(m); 363 364 mm_request_receive_expect(pmonitor->m_recvfd, 365 MONITOR_ANS_AUTH2_READ_BANNER, m); 366 if ((r = sshbuf_get_cstring(m, &banner, NULL)) != 0) 367 fatal_fr(r, "parse"); 368 sshbuf_free(m); 369 370 /* treat empty banner as missing banner */ 371 if (strlen(banner) == 0) { 372 free(banner); 373 banner = NULL; 374 } 375 return (banner); 376 } 377 378 /* Inform the privileged process about service and style */ 379 380 void 381 mm_inform_authserv(char *service, char *style) 382 { 383 struct sshbuf *m; 384 int r; 385 386 debug3_f("entering"); 387 388 if ((m = sshbuf_new()) == NULL) 389 fatal_f("sshbuf_new failed"); 390 if ((r = sshbuf_put_cstring(m, service)) != 0 || 391 (r = sshbuf_put_cstring(m, style ? style : "")) != 0) 392 fatal_fr(r, "assemble"); 393 394 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, m); 395 396 sshbuf_free(m); 397 } 398 399 /* Do the password authentication */ 400 int 401 mm_auth_password(struct ssh *ssh, char *password) 402 { 403 struct sshbuf *m; 404 int r, authenticated = 0; 405 #ifdef USE_PAM 406 u_int maxtries = 0; 407 #endif 408 409 debug3_f("entering"); 410 411 if ((m = sshbuf_new()) == NULL) 412 fatal_f("sshbuf_new failed"); 413 if ((r = sshbuf_put_cstring(m, password)) != 0) 414 fatal_fr(r, "assemble"); 415 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, m); 416 417 debug3_f("waiting for MONITOR_ANS_AUTHPASSWORD"); 418 mm_request_receive_expect(pmonitor->m_recvfd, 419 MONITOR_ANS_AUTHPASSWORD, m); 420 421 if ((r = sshbuf_get_u32(m, &authenticated)) != 0) 422 fatal_fr(r, "parse"); 423 #ifdef USE_PAM 424 if ((r = sshbuf_get_u32(m, &maxtries)) != 0) 425 fatal_fr(r, "parse PAM"); 426 if (maxtries > INT_MAX) 427 fatal_fr(r, "bad maxtries"); 428 sshpam_set_maxtries_reached(maxtries); 429 #endif 430 431 sshbuf_free(m); 432 433 debug3_f("user %sauthenticated", authenticated ? "" : "not "); 434 return (authenticated); 435 } 436 437 int 438 mm_user_key_allowed(struct ssh *ssh, struct passwd *pw, struct sshkey *key, 439 int pubkey_auth_attempt, struct sshauthopt **authoptp) 440 { 441 return (mm_key_allowed(MM_USERKEY, NULL, NULL, key, 442 pubkey_auth_attempt, authoptp)); 443 } 444 445 int 446 mm_hostbased_key_allowed(struct ssh *ssh, struct passwd *pw, 447 const char *user, const char *host, struct sshkey *key) 448 { 449 return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0, NULL)); 450 } 451 452 int 453 mm_key_allowed(enum mm_keytype type, const char *user, const char *host, 454 struct sshkey *key, int pubkey_auth_attempt, struct sshauthopt **authoptp) 455 { 456 struct sshbuf *m; 457 int r, allowed = 0; 458 struct sshauthopt *opts = NULL; 459 460 debug3_f("entering"); 461 462 if (authoptp != NULL) 463 *authoptp = NULL; 464 465 if ((m = sshbuf_new()) == NULL) 466 fatal_f("sshbuf_new failed"); 467 if ((r = sshbuf_put_u32(m, type)) != 0 || 468 (r = sshbuf_put_cstring(m, user ? user : "")) != 0 || 469 (r = sshbuf_put_cstring(m, host ? host : "")) != 0 || 470 (r = sshkey_puts(key, m)) != 0 || 471 (r = sshbuf_put_u32(m, pubkey_auth_attempt)) != 0) 472 fatal_fr(r, "assemble"); 473 474 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, m); 475 476 debug3_f("waiting for MONITOR_ANS_KEYALLOWED"); 477 mm_request_receive_expect(pmonitor->m_recvfd, 478 MONITOR_ANS_KEYALLOWED, m); 479 480 if ((r = sshbuf_get_u32(m, &allowed)) != 0) 481 fatal_fr(r, "parse"); 482 if (allowed && type == MM_USERKEY && 483 (r = sshauthopt_deserialise(m, &opts)) != 0) 484 fatal_fr(r, "sshauthopt_deserialise"); 485 sshbuf_free(m); 486 487 if (authoptp != NULL) { 488 *authoptp = opts; 489 opts = NULL; 490 } 491 sshauthopt_free(opts); 492 493 return allowed; 494 } 495 496 /* 497 * This key verify needs to send the key type along, because the 498 * privileged parent makes the decision if the key is allowed 499 * for authentication. 500 */ 501 502 int 503 mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen, 504 const u_char *data, size_t datalen, const char *sigalg, u_int compat, 505 struct sshkey_sig_details **sig_detailsp) 506 { 507 struct sshbuf *m; 508 u_int encoded_ret = 0; 509 int r; 510 u_char sig_details_present, flags; 511 u_int counter; 512 513 debug3_f("entering"); 514 515 if (sig_detailsp != NULL) 516 *sig_detailsp = NULL; 517 if ((m = sshbuf_new()) == NULL) 518 fatal_f("sshbuf_new failed"); 519 if ((r = sshkey_puts(key, m)) != 0 || 520 (r = sshbuf_put_string(m, sig, siglen)) != 0 || 521 (r = sshbuf_put_string(m, data, datalen)) != 0 || 522 (r = sshbuf_put_cstring(m, sigalg == NULL ? "" : sigalg)) != 0) 523 fatal_fr(r, "assemble"); 524 525 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, m); 526 527 debug3_f("waiting for MONITOR_ANS_KEYVERIFY"); 528 mm_request_receive_expect(pmonitor->m_recvfd, 529 MONITOR_ANS_KEYVERIFY, m); 530 531 if ((r = sshbuf_get_u32(m, &encoded_ret)) != 0 || 532 (r = sshbuf_get_u8(m, &sig_details_present)) != 0) 533 fatal_fr(r, "parse"); 534 if (sig_details_present && encoded_ret == 0) { 535 if ((r = sshbuf_get_u32(m, &counter)) != 0 || 536 (r = sshbuf_get_u8(m, &flags)) != 0) 537 fatal_fr(r, "parse sig_details"); 538 if (sig_detailsp != NULL) { 539 *sig_detailsp = xcalloc(1, sizeof(**sig_detailsp)); 540 (*sig_detailsp)->sk_counter = counter; 541 (*sig_detailsp)->sk_flags = flags; 542 } 543 } 544 545 sshbuf_free(m); 546 547 if (encoded_ret != 0) 548 return SSH_ERR_SIGNATURE_INVALID; 549 return 0; 550 } 551 552 void 553 mm_send_keystate(struct ssh *ssh, struct monitor *monitor) 554 { 555 struct sshbuf *m; 556 int r; 557 558 if ((m = sshbuf_new()) == NULL) 559 fatal_f("sshbuf_new failed"); 560 if ((r = ssh_packet_get_state(ssh, m)) != 0) 561 fatal_fr(r, "ssh_packet_get_state"); 562 mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m); 563 debug3_f("Finished sending state"); 564 sshbuf_free(m); 565 } 566 567 int 568 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen) 569 { 570 struct sshbuf *m; 571 char *p, *msg; 572 int success = 0, tmp1 = -1, tmp2 = -1, r; 573 574 /* Kludge: ensure there are fds free to receive the pty/tty */ 575 if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 || 576 (tmp2 = dup(pmonitor->m_recvfd)) == -1) { 577 error_f("cannot allocate fds for pty"); 578 if (tmp1 >= 0) 579 close(tmp1); 580 return 0; 581 } 582 close(tmp1); 583 close(tmp2); 584 585 if ((m = sshbuf_new()) == NULL) 586 fatal_f("sshbuf_new failed"); 587 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, m); 588 589 debug3_f("waiting for MONITOR_ANS_PTY"); 590 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, m); 591 592 if ((r = sshbuf_get_u32(m, &success)) != 0) 593 fatal_fr(r, "parse success"); 594 if (success == 0) { 595 debug3_f("pty alloc failed"); 596 sshbuf_free(m); 597 return (0); 598 } 599 if ((r = sshbuf_get_cstring(m, &p, NULL)) != 0 || 600 (r = sshbuf_get_cstring(m, &msg, NULL)) != 0) 601 fatal_fr(r, "parse"); 602 sshbuf_free(m); 603 604 strlcpy(namebuf, p, namebuflen); /* Possible truncation */ 605 free(p); 606 607 if ((r = sshbuf_put(loginmsg, msg, strlen(msg))) != 0) 608 fatal_fr(r, "put loginmsg"); 609 free(msg); 610 611 if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 || 612 (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1) 613 fatal_f("receive fds failed"); 614 615 /* Success */ 616 return (1); 617 } 618 619 void 620 mm_session_pty_cleanup2(Session *s) 621 { 622 struct sshbuf *m; 623 int r; 624 625 if (s->ttyfd == -1) 626 return; 627 if ((m = sshbuf_new()) == NULL) 628 fatal_f("sshbuf_new failed"); 629 if ((r = sshbuf_put_cstring(m, s->tty)) != 0) 630 fatal_fr(r, "assmble"); 631 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, m); 632 sshbuf_free(m); 633 634 /* closed dup'ed master */ 635 if (s->ptymaster != -1 && close(s->ptymaster) == -1) 636 error("close(s->ptymaster/%d): %s", 637 s->ptymaster, strerror(errno)); 638 639 /* unlink pty from session */ 640 s->ttyfd = -1; 641 } 642 643 #ifdef USE_PAM 644 void 645 mm_start_pam(struct ssh *ssh) 646 { 647 struct sshbuf *m; 648 649 debug3("%s entering", __func__); 650 if (!options.use_pam) 651 fatal("UsePAM=no, but ended up in %s anyway", __func__); 652 if ((m = sshbuf_new()) == NULL) 653 fatal("%s: sshbuf_new failed", __func__); 654 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, m); 655 656 sshbuf_free(m); 657 } 658 659 u_int 660 mm_do_pam_account(void) 661 { 662 struct sshbuf *m; 663 u_int ret; 664 char *msg; 665 size_t msglen; 666 int r; 667 668 debug3("%s entering", __func__); 669 if (!options.use_pam) 670 fatal("UsePAM=no, but ended up in %s anyway", __func__); 671 672 if ((m = sshbuf_new()) == NULL) 673 fatal("%s: sshbuf_new failed", __func__); 674 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, m); 675 676 mm_request_receive_expect(pmonitor->m_recvfd, 677 MONITOR_ANS_PAM_ACCOUNT, m); 678 if ((r = sshbuf_get_u32(m, &ret)) != 0 || 679 (r = sshbuf_get_cstring(m, &msg, &msglen)) != 0 || 680 (r = sshbuf_put(loginmsg, msg, msglen)) != 0) 681 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 682 683 free(msg); 684 sshbuf_free(m); 685 686 debug3("%s returning %d", __func__, ret); 687 688 return (ret); 689 } 690 691 void * 692 mm_sshpam_init_ctx(Authctxt *authctxt) 693 { 694 struct sshbuf *m; 695 int r, success; 696 697 debug3("%s", __func__); 698 if ((m = sshbuf_new()) == NULL) 699 fatal("%s: sshbuf_new failed", __func__); 700 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, m); 701 debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__); 702 mm_request_receive_expect(pmonitor->m_recvfd, 703 MONITOR_ANS_PAM_INIT_CTX, m); 704 if ((r = sshbuf_get_u32(m, &success)) != 0) 705 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 706 if (success == 0) { 707 debug3("%s: pam_init_ctx failed", __func__); 708 sshbuf_free(m); 709 return (NULL); 710 } 711 sshbuf_free(m); 712 return (authctxt); 713 } 714 715 int 716 mm_sshpam_query(void *ctx, char **name, char **info, 717 u_int *num, char ***prompts, u_int **echo_on) 718 { 719 struct sshbuf *m; 720 u_int i, n; 721 int r, ret; 722 723 debug3("%s", __func__); 724 if ((m = sshbuf_new()) == NULL) 725 fatal("%s: sshbuf_new failed", __func__); 726 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_QUERY, m); 727 debug3("%s: waiting for MONITOR_ANS_PAM_QUERY", __func__); 728 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_QUERY, m); 729 if ((r = sshbuf_get_u32(m, &ret)) != 0 || 730 (r = sshbuf_get_cstring(m, name, NULL)) != 0 || 731 (r = sshbuf_get_cstring(m, info, NULL)) != 0 || 732 (r = sshbuf_get_u32(m, &n)) != 0 || 733 (r = sshbuf_get_u32(m, num)) != 0) 734 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 735 debug3("%s: pam_query returned %d", __func__, ret); 736 sshpam_set_maxtries_reached(n); 737 if (*num > PAM_MAX_NUM_MSG) 738 fatal("%s: received %u PAM messages, expected <= %u", 739 __func__, *num, PAM_MAX_NUM_MSG); 740 *prompts = xcalloc((*num + 1), sizeof(char *)); 741 *echo_on = xcalloc((*num + 1), sizeof(u_int)); 742 for (i = 0; i < *num; ++i) { 743 if ((r = sshbuf_get_cstring(m, &((*prompts)[i]), NULL)) != 0 || 744 (r = sshbuf_get_u32(m, &((*echo_on)[i]))) != 0) 745 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 746 } 747 sshbuf_free(m); 748 return (ret); 749 } 750 751 int 752 mm_sshpam_respond(void *ctx, u_int num, char **resp) 753 { 754 struct sshbuf *m; 755 u_int n, i; 756 int r, ret; 757 758 debug3("%s", __func__); 759 if ((m = sshbuf_new()) == NULL) 760 fatal("%s: sshbuf_new failed", __func__); 761 if ((r = sshbuf_put_u32(m, num)) != 0) 762 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 763 for (i = 0; i < num; ++i) { 764 if ((r = sshbuf_put_cstring(m, resp[i])) != 0) 765 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 766 } 767 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, m); 768 debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__); 769 mm_request_receive_expect(pmonitor->m_recvfd, 770 MONITOR_ANS_PAM_RESPOND, m); 771 if ((r = sshbuf_get_u32(m, &n)) != 0) 772 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 773 ret = (int)n; /* XXX */ 774 debug3("%s: pam_respond returned %d", __func__, ret); 775 sshbuf_free(m); 776 return (ret); 777 } 778 779 void 780 mm_sshpam_free_ctx(void *ctxtp) 781 { 782 struct sshbuf *m; 783 784 debug3("%s", __func__); 785 if ((m = sshbuf_new()) == NULL) 786 fatal("%s: sshbuf_new failed", __func__); 787 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_FREE_CTX, m); 788 debug3("%s: waiting for MONITOR_ANS_PAM_FREE_CTX", __func__); 789 mm_request_receive_expect(pmonitor->m_recvfd, 790 MONITOR_ANS_PAM_FREE_CTX, m); 791 sshbuf_free(m); 792 } 793 #endif /* USE_PAM */ 794 795 /* Request process termination */ 796 797 void 798 mm_terminate(void) 799 { 800 struct sshbuf *m; 801 802 if ((m = sshbuf_new()) == NULL) 803 fatal_f("sshbuf_new failed"); 804 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, m); 805 sshbuf_free(m); 806 } 807 808 static void 809 mm_chall_setup(char **name, char **infotxt, u_int *numprompts, 810 char ***prompts, u_int **echo_on) 811 { 812 *name = xstrdup(""); 813 *infotxt = xstrdup(""); 814 *numprompts = 1; 815 *prompts = xcalloc(*numprompts, sizeof(char *)); 816 *echo_on = xcalloc(*numprompts, sizeof(u_int)); 817 (*echo_on)[0] = 0; 818 } 819 820 int 821 mm_bsdauth_query(void *ctx, char **name, char **infotxt, 822 u_int *numprompts, char ***prompts, u_int **echo_on) 823 { 824 struct sshbuf *m; 825 u_int success; 826 char *challenge; 827 int r; 828 829 debug3_f("entering"); 830 831 if ((m = sshbuf_new()) == NULL) 832 fatal_f("sshbuf_new failed"); 833 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, m); 834 835 mm_request_receive_expect(pmonitor->m_recvfd, 836 MONITOR_ANS_BSDAUTHQUERY, m); 837 if ((r = sshbuf_get_u32(m, &success)) != 0) 838 fatal_fr(r, "parse success"); 839 if (success == 0) { 840 debug3_f("no challenge"); 841 sshbuf_free(m); 842 return (-1); 843 } 844 845 /* Get the challenge, and format the response */ 846 if ((r = sshbuf_get_cstring(m, &challenge, NULL)) != 0) 847 fatal_fr(r, "parse challenge"); 848 sshbuf_free(m); 849 850 mm_chall_setup(name, infotxt, numprompts, prompts, echo_on); 851 (*prompts)[0] = challenge; 852 853 debug3_f("received challenge: %s", challenge); 854 855 return (0); 856 } 857 858 int 859 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses) 860 { 861 struct sshbuf *m; 862 int r, authok; 863 864 debug3_f("entering"); 865 if (numresponses != 1) 866 return (-1); 867 868 if ((m = sshbuf_new()) == NULL) 869 fatal_f("sshbuf_new failed"); 870 if ((r = sshbuf_put_cstring(m, responses[0])) != 0) 871 fatal_fr(r, "assemble"); 872 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, m); 873 874 mm_request_receive_expect(pmonitor->m_recvfd, 875 MONITOR_ANS_BSDAUTHRESPOND, m); 876 877 if ((r = sshbuf_get_u32(m, &authok)) != 0) 878 fatal_fr(r, "parse"); 879 sshbuf_free(m); 880 881 return ((authok == 0) ? -1 : 0); 882 } 883 884 #ifdef SSH_AUDIT_EVENTS 885 void 886 mm_audit_event(struct ssh *ssh, ssh_audit_event_t event) 887 { 888 struct sshbuf *m; 889 int r; 890 891 debug3("%s entering", __func__); 892 893 if ((m = sshbuf_new()) == NULL) 894 fatal("%s: sshbuf_new failed", __func__); 895 if ((r = sshbuf_put_u32(m, event)) != 0) 896 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 897 898 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_EVENT, m); 899 sshbuf_free(m); 900 } 901 902 void 903 mm_audit_run_command(const char *command) 904 { 905 struct sshbuf *m; 906 int r; 907 908 debug3("%s entering command %s", __func__, command); 909 910 if ((m = sshbuf_new()) == NULL) 911 fatal("%s: sshbuf_new failed", __func__); 912 if ((r = sshbuf_put_cstring(m, command)) != 0) 913 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 914 915 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_COMMAND, m); 916 sshbuf_free(m); 917 } 918 #endif /* SSH_AUDIT_EVENTS */ 919 920 #ifdef GSSAPI 921 OM_uint32 922 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid) 923 { 924 struct sshbuf *m; 925 OM_uint32 major; 926 int r; 927 928 /* Client doesn't get to see the context */ 929 *ctx = NULL; 930 931 if ((m = sshbuf_new()) == NULL) 932 fatal_f("sshbuf_new failed"); 933 if ((r = sshbuf_put_string(m, goid->elements, goid->length)) != 0) 934 fatal_fr(r, "assemble"); 935 936 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, m); 937 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, m); 938 939 if ((r = sshbuf_get_u32(m, &major)) != 0) 940 fatal_fr(r, "parse"); 941 942 sshbuf_free(m); 943 return (major); 944 } 945 946 OM_uint32 947 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in, 948 gss_buffer_desc *out, OM_uint32 *flagsp) 949 { 950 struct sshbuf *m; 951 OM_uint32 major; 952 u_int flags; 953 int r; 954 955 if ((m = sshbuf_new()) == NULL) 956 fatal_f("sshbuf_new failed"); 957 if ((r = sshbuf_put_string(m, in->value, in->length)) != 0) 958 fatal_fr(r, "assemble"); 959 960 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, m); 961 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, m); 962 963 if ((r = sshbuf_get_u32(m, &major)) != 0 || 964 (r = ssh_gssapi_get_buffer_desc(m, out)) != 0) 965 fatal_fr(r, "parse"); 966 if (flagsp != NULL) { 967 if ((r = sshbuf_get_u32(m, &flags)) != 0) 968 fatal_fr(r, "parse flags"); 969 *flagsp = flags; 970 } 971 972 sshbuf_free(m); 973 974 return (major); 975 } 976 977 OM_uint32 978 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) 979 { 980 struct sshbuf *m; 981 OM_uint32 major; 982 int r; 983 984 if ((m = sshbuf_new()) == NULL) 985 fatal_f("sshbuf_new failed"); 986 if ((r = sshbuf_put_string(m, gssbuf->value, gssbuf->length)) != 0 || 987 (r = sshbuf_put_string(m, gssmic->value, gssmic->length)) != 0) 988 fatal_fr(r, "assemble"); 989 990 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, m); 991 mm_request_receive_expect(pmonitor->m_recvfd, 992 MONITOR_ANS_GSSCHECKMIC, m); 993 994 if ((r = sshbuf_get_u32(m, &major)) != 0) 995 fatal_fr(r, "parse"); 996 sshbuf_free(m); 997 return(major); 998 } 999 1000 int 1001 mm_ssh_gssapi_userok(char *user) 1002 { 1003 struct sshbuf *m; 1004 int r, authenticated = 0; 1005 1006 if ((m = sshbuf_new()) == NULL) 1007 fatal_f("sshbuf_new failed"); 1008 1009 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, m); 1010 mm_request_receive_expect(pmonitor->m_recvfd, 1011 MONITOR_ANS_GSSUSEROK, m); 1012 1013 if ((r = sshbuf_get_u32(m, &authenticated)) != 0) 1014 fatal_fr(r, "parse"); 1015 1016 sshbuf_free(m); 1017 debug3_f("user %sauthenticated", authenticated ? "" : "not "); 1018 return (authenticated); 1019 } 1020 #endif /* GSSAPI */ 1021