1 /* $NetBSD: monitor_wrap.c,v 1.29 2021/03/05 17:47:16 christos Exp $ */ 2 /* $OpenBSD: monitor_wrap.c,v 1.122 2020/11/27 00:37:10 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 1.29 2021/03/05 17:47:16 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(const char *file, const char *func, int line, 91 LogLevel level, const char *msg, void *ctx) 92 { 93 struct sshbuf *log_msg; 94 struct monitor *mon = (struct monitor *)ctx; 95 int r; 96 size_t len; 97 98 if (mon->m_log_sendfd == -1) 99 fatal_f("no log channel"); 100 101 if ((log_msg = sshbuf_new()) == NULL) 102 fatal_f("sshbuf_new failed"); 103 104 if ((r = sshbuf_put_u32(log_msg, 0)) != 0 || /* length; filled below */ 105 (r = sshbuf_put_cstring(log_msg, file)) != 0 || 106 (r = sshbuf_put_cstring(log_msg, func)) != 0 || 107 (r = sshbuf_put_u32(log_msg, (u_int)line)) != 0 || 108 (r = sshbuf_put_u32(log_msg, level)) != 0 || 109 (r = sshbuf_put_cstring(log_msg, msg)) != 0) 110 fatal_fr(r, "assemble"); 111 if ((len = sshbuf_len(log_msg)) < 4 || len > 0xffffffff) 112 fatal_f("bad length %zu", len); 113 POKE_U32(sshbuf_mutable_ptr(log_msg), len - 4); 114 if (atomicio(vwrite, mon->m_log_sendfd, 115 sshbuf_mutable_ptr(log_msg), len) != len) 116 fatal_f("write: %s", strerror(errno)); 117 sshbuf_free(log_msg); 118 } 119 120 int 121 mm_is_monitor(void) 122 { 123 /* 124 * m_pid is only set in the privileged part, and 125 * points to the unprivileged child. 126 */ 127 return (pmonitor && pmonitor->m_pid > 0); 128 } 129 130 void 131 mm_request_send(int sock, enum monitor_reqtype type, struct sshbuf *m) 132 { 133 size_t mlen = sshbuf_len(m); 134 u_char buf[5]; 135 136 debug3_f("entering, type %d", type); 137 138 if (mlen >= 0xffffffff) 139 fatal_f("bad length %zu", mlen); 140 POKE_U32(buf, mlen + 1); 141 buf[4] = (u_char) type; /* 1st byte of payload is mesg-type */ 142 if (atomicio(vwrite, sock, buf, sizeof(buf)) != sizeof(buf)) 143 fatal_f("write: %s", strerror(errno)); 144 if (atomicio(vwrite, sock, sshbuf_mutable_ptr(m), mlen) != mlen) 145 fatal_f("write: %s", strerror(errno)); 146 } 147 148 void 149 mm_request_receive(int sock, struct sshbuf *m) 150 { 151 u_char buf[4], *p = NULL; 152 u_int msg_len; 153 int r; 154 155 debug3_f("entering"); 156 157 if (atomicio(read, sock, buf, sizeof(buf)) != sizeof(buf)) { 158 if (errno == EPIPE) 159 cleanup_exit(254); 160 fatal_f("read: %s", strerror(errno)); 161 } 162 msg_len = PEEK_U32(buf); 163 if (msg_len > 256 * 1024) 164 fatal_f("read: bad msg_len %d", msg_len); 165 sshbuf_reset(m); 166 if ((r = sshbuf_reserve(m, msg_len, &p)) != 0) 167 fatal_fr(r, "reserve"); 168 if (atomicio(read, sock, p, msg_len) != msg_len) 169 fatal_f("read: %s", strerror(errno)); 170 } 171 172 void 173 mm_request_receive_expect(int sock, enum monitor_reqtype type, struct sshbuf *m) 174 { 175 u_char rtype; 176 int r; 177 178 debug3_f("entering, type %d", type); 179 180 mm_request_receive(sock, m); 181 if ((r = sshbuf_get_u8(m, &rtype)) != 0) 182 fatal_fr(r, "parse"); 183 if (rtype != type) 184 fatal_f("read: rtype %d != type %d", rtype, type); 185 } 186 187 #ifdef WITH_OPENSSL 188 DH * 189 mm_choose_dh(int min, int nbits, int max) 190 { 191 BIGNUM *p, *g; 192 int r; 193 u_char success = 0; 194 struct sshbuf *m; 195 196 if ((m = sshbuf_new()) == NULL) 197 fatal_f("sshbuf_new failed"); 198 if ((r = sshbuf_put_u32(m, min)) != 0 || 199 (r = sshbuf_put_u32(m, nbits)) != 0 || 200 (r = sshbuf_put_u32(m, max)) != 0) 201 fatal_fr(r, "assemble"); 202 203 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_MODULI, m); 204 205 debug3_f("waiting for MONITOR_ANS_MODULI"); 206 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_MODULI, m); 207 208 if ((r = sshbuf_get_u8(m, &success)) != 0) 209 fatal_fr(r, "parse success"); 210 if (success == 0) 211 fatal_f("MONITOR_ANS_MODULI failed"); 212 213 if ((r = sshbuf_get_bignum2(m, &p)) != 0 || 214 (r = sshbuf_get_bignum2(m, &g)) != 0) 215 fatal_fr(r, "parse group"); 216 217 debug3_f("remaining %zu", sshbuf_len(m)); 218 sshbuf_free(m); 219 220 return (dh_new_group(g, p)); 221 } 222 #endif 223 224 int 225 mm_sshkey_sign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp, 226 const u_char *data, size_t datalen, const char *hostkey_alg, 227 const char *sk_provider, const char *sk_pin, u_int compat) 228 { 229 struct kex *kex = *pmonitor->m_pkex; 230 struct sshbuf *m; 231 u_int ndx = kex->host_key_index(key, 0, ssh); 232 int r; 233 234 debug3_f("entering"); 235 if ((m = sshbuf_new()) == NULL) 236 fatal_f("sshbuf_new failed"); 237 if ((r = sshbuf_put_u32(m, ndx)) != 0 || 238 (r = sshbuf_put_string(m, data, datalen)) != 0 || 239 (r = sshbuf_put_cstring(m, hostkey_alg)) != 0 || 240 (r = sshbuf_put_u32(m, compat)) != 0) 241 fatal_fr(r, "assemble"); 242 243 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, m); 244 245 debug3_f("waiting for MONITOR_ANS_SIGN"); 246 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, m); 247 if ((r = sshbuf_get_string(m, sigp, lenp)) != 0) 248 fatal_fr(r, "parse"); 249 sshbuf_free(m); 250 251 return (0); 252 } 253 254 #define GETPW(b, id) \ 255 do { \ 256 if ((r = sshbuf_get_string_direct(b, &p, &len)) != 0) \ 257 fatal_fr(r, "parse pw %s", #id); \ 258 if (len != sizeof(pw->id)) \ 259 fatal_fr(r, "bad length for %s", #id); \ 260 memcpy(&pw->id, p, len); \ 261 } while (0) 262 263 struct passwd * 264 mm_getpwnamallow(struct ssh *ssh, const char *username) 265 { 266 struct sshbuf *m; 267 struct passwd *pw; 268 size_t len; 269 u_int i; 270 ServerOptions *newopts; 271 int r; 272 u_char ok; 273 const u_char *p; 274 275 debug3_f("entering"); 276 277 if ((m = sshbuf_new()) == NULL) 278 fatal_f("sshbuf_new failed"); 279 if ((r = sshbuf_put_cstring(m, username)) != 0) 280 fatal_fr(r, "assemble"); 281 282 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, m); 283 284 debug3_f("waiting for MONITOR_ANS_PWNAM"); 285 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, m); 286 287 if ((r = sshbuf_get_u8(m, &ok)) != 0) 288 fatal_fr(r, "parse success"); 289 if (ok == 0) { 290 pw = NULL; 291 goto out; 292 } 293 294 pw = xcalloc(sizeof(*pw), 1); 295 GETPW(m, pw_uid); 296 GETPW(m, pw_gid); 297 GETPW(m, pw_change); 298 GETPW(m, pw_expire); 299 if ((r = sshbuf_get_cstring(m, &pw->pw_name, NULL)) != 0 || 300 (r = sshbuf_get_cstring(m, &pw->pw_passwd, NULL)) != 0 || 301 (r = sshbuf_get_cstring(m, &pw->pw_gecos, NULL)) != 0 || 302 (r = sshbuf_get_cstring(m, &pw->pw_class, NULL)) != 0 || 303 (r = sshbuf_get_cstring(m, &pw->pw_dir, NULL)) != 0 || 304 (r = sshbuf_get_cstring(m, &pw->pw_shell, NULL)) != 0) 305 fatal_fr(r, "parse pw"); 306 307 out: 308 /* copy options block as a Match directive may have changed some */ 309 if ((r = sshbuf_get_string_direct(m, &p, &len)) != 0) 310 fatal_fr(r, "parse opts"); 311 if (len != sizeof(*newopts)) 312 fatal_f("option block size mismatch"); 313 newopts = xcalloc(sizeof(*newopts), 1); 314 memcpy(newopts, p, sizeof(*newopts)); 315 316 #define M_CP_STROPT(x) do { \ 317 if (newopts->x != NULL && \ 318 (r = sshbuf_get_cstring(m, &newopts->x, NULL)) != 0) \ 319 fatal_fr(r, "parse %s", #x); \ 320 } while (0) 321 #define M_CP_STRARRAYOPT(x, nx) do { \ 322 newopts->x = newopts->nx == 0 ? \ 323 NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \ 324 for (i = 0; i < newopts->nx; i++) { \ 325 if ((r = sshbuf_get_cstring(m, \ 326 &newopts->x[i], NULL)) != 0) \ 327 fatal_fr(r, "parse %s", #x); \ 328 } \ 329 } while (0) 330 /* See comment in servconf.h */ 331 COPY_MATCH_STRING_OPTS(); 332 #undef M_CP_STROPT 333 #undef M_CP_STRARRAYOPT 334 335 copy_set_server_options(&options, newopts, 1); 336 log_change_level(options.log_level); 337 log_verbose_reset(); 338 for (i = 0; i < options.num_log_verbose; i++) 339 log_verbose_add(options.log_verbose[i]); 340 process_permitopen(ssh, &options); 341 free(newopts); 342 343 sshbuf_free(m); 344 345 return (pw); 346 } 347 348 char * 349 mm_auth2_read_banner(void) 350 { 351 struct sshbuf *m; 352 char *banner; 353 int r; 354 355 debug3_f("entering"); 356 357 if ((m = sshbuf_new()) == NULL) 358 fatal_f("sshbuf_new failed"); 359 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, m); 360 sshbuf_reset(m); 361 362 mm_request_receive_expect(pmonitor->m_recvfd, 363 MONITOR_ANS_AUTH2_READ_BANNER, m); 364 if ((r = sshbuf_get_cstring(m, &banner, NULL)) != 0) 365 fatal_fr(r, "parse"); 366 sshbuf_free(m); 367 368 /* treat empty banner as missing banner */ 369 if (strlen(banner) == 0) { 370 free(banner); 371 banner = NULL; 372 } 373 return (banner); 374 } 375 376 /* Inform the privileged process about service and style */ 377 378 void 379 mm_inform_authserv(char *service, char *style) 380 { 381 struct sshbuf *m; 382 int r; 383 384 debug3_f("entering"); 385 386 if ((m = sshbuf_new()) == NULL) 387 fatal_f("sshbuf_new failed"); 388 if ((r = sshbuf_put_cstring(m, service)) != 0 || 389 (r = sshbuf_put_cstring(m, style ? style : "")) != 0) 390 fatal_fr(r, "assemble"); 391 392 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, m); 393 394 sshbuf_free(m); 395 } 396 397 /* Do the password authentication */ 398 int 399 mm_auth_password(struct ssh *ssh, const char *password) 400 { 401 struct sshbuf *m; 402 int r; 403 u_int authenticated = 0; 404 405 debug3_f("entering"); 406 407 if ((m = sshbuf_new()) == NULL) 408 fatal_f("sshbuf_new failed"); 409 if ((r = sshbuf_put_cstring(m, password)) != 0) 410 fatal_fr(r, "assemble"); 411 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, m); 412 413 debug3_f("waiting for MONITOR_ANS_AUTHPASSWORD"); 414 mm_request_receive_expect(pmonitor->m_recvfd, 415 MONITOR_ANS_AUTHPASSWORD, m); 416 417 if ((r = sshbuf_get_u32(m, &authenticated)) != 0) 418 fatal_fr(r, "parse"); 419 420 sshbuf_free(m); 421 422 debug3_f("user %sauthenticated", authenticated ? "" : "not "); 423 return (authenticated); 424 } 425 426 int 427 mm_user_key_allowed(struct ssh *ssh, struct passwd *pw, struct sshkey *key, 428 int pubkey_auth_attempt, struct sshauthopt **authoptp) 429 { 430 return (mm_key_allowed(MM_USERKEY, NULL, NULL, key, 431 pubkey_auth_attempt, authoptp)); 432 } 433 434 int 435 mm_hostbased_key_allowed(struct ssh *ssh, struct passwd *pw, 436 const char *user, const char *host, struct sshkey *key) 437 { 438 return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0, NULL)); 439 } 440 441 int 442 mm_key_allowed(enum mm_keytype type, const char *user, const char *host, 443 struct sshkey *key, int pubkey_auth_attempt, struct sshauthopt **authoptp) 444 { 445 struct sshbuf *m; 446 int r; 447 u_int allowed = 0; 448 struct sshauthopt *opts = NULL; 449 450 debug3_f("entering"); 451 452 if (authoptp != NULL) 453 *authoptp = NULL; 454 455 if ((m = sshbuf_new()) == NULL) 456 fatal_f("sshbuf_new failed"); 457 if ((r = sshbuf_put_u32(m, type)) != 0 || 458 (r = sshbuf_put_cstring(m, user ? user : "")) != 0 || 459 (r = sshbuf_put_cstring(m, host ? host : "")) != 0 || 460 (r = sshkey_puts(key, m)) != 0 || 461 (r = sshbuf_put_u32(m, pubkey_auth_attempt)) != 0) 462 fatal_fr(r, "assemble"); 463 464 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, m); 465 466 debug3_f("waiting for MONITOR_ANS_KEYALLOWED"); 467 mm_request_receive_expect(pmonitor->m_recvfd, 468 MONITOR_ANS_KEYALLOWED, m); 469 470 if ((r = sshbuf_get_u32(m, &allowed)) != 0) 471 fatal_fr(r, "parse"); 472 if (allowed && type == MM_USERKEY && 473 (r = sshauthopt_deserialise(m, &opts)) != 0) 474 fatal_fr(r, "sshauthopt_deserialise"); 475 sshbuf_free(m); 476 477 if (authoptp != NULL) { 478 *authoptp = opts; 479 opts = NULL; 480 } 481 sshauthopt_free(opts); 482 483 return allowed; 484 } 485 486 /* 487 * This key verify needs to send the key type along, because the 488 * privileged parent makes the decision if the key is allowed 489 * for authentication. 490 */ 491 492 int 493 mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen, 494 const u_char *data, size_t datalen, const char *sigalg, u_int compat, 495 struct sshkey_sig_details **sig_detailsp) 496 { 497 struct sshbuf *m; 498 u_int encoded_ret = 0; 499 int r; 500 u_char sig_details_present, flags; 501 u_int counter; 502 503 debug3_f("entering"); 504 505 if (sig_detailsp != NULL) 506 *sig_detailsp = NULL; 507 if ((m = sshbuf_new()) == NULL) 508 fatal_f("sshbuf_new failed"); 509 if ((r = sshkey_puts(key, m)) != 0 || 510 (r = sshbuf_put_string(m, sig, siglen)) != 0 || 511 (r = sshbuf_put_string(m, data, datalen)) != 0 || 512 (r = sshbuf_put_cstring(m, sigalg == NULL ? "" : sigalg)) != 0) 513 fatal_fr(r, "assemble"); 514 515 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, m); 516 517 debug3_f("waiting for MONITOR_ANS_KEYVERIFY"); 518 mm_request_receive_expect(pmonitor->m_recvfd, 519 MONITOR_ANS_KEYVERIFY, m); 520 521 if ((r = sshbuf_get_u32(m, &encoded_ret)) != 0 || 522 (r = sshbuf_get_u8(m, &sig_details_present)) != 0) 523 fatal_fr(r, "parse"); 524 if (sig_details_present && encoded_ret == 0) { 525 if ((r = sshbuf_get_u32(m, &counter)) != 0 || 526 (r = sshbuf_get_u8(m, &flags)) != 0) 527 fatal_fr(r, "parse sig_details"); 528 if (sig_detailsp != NULL) { 529 *sig_detailsp = xcalloc(1, sizeof(**sig_detailsp)); 530 (*sig_detailsp)->sk_counter = counter; 531 (*sig_detailsp)->sk_flags = flags; 532 } 533 } 534 535 sshbuf_free(m); 536 537 if (encoded_ret != 0) 538 return SSH_ERR_SIGNATURE_INVALID; 539 return 0; 540 } 541 542 void 543 mm_send_keystate(struct ssh *ssh, struct monitor *monitor) 544 { 545 struct sshbuf *m; 546 int r; 547 548 if ((m = sshbuf_new()) == NULL) 549 fatal_f("sshbuf_new failed"); 550 if ((r = ssh_packet_get_state(ssh, m)) != 0) 551 fatal_fr(r, "ssh_packet_get_state"); 552 mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m); 553 debug3_f("Finished sending state"); 554 sshbuf_free(m); 555 } 556 557 int 558 mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen) 559 { 560 struct sshbuf *m; 561 char *p, *msg; 562 u_int success = 0; 563 int tmp1 = -1, tmp2 = -1, r; 564 565 /* Kludge: ensure there are fds free to receive the pty/tty */ 566 if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 || 567 (tmp2 = dup(pmonitor->m_recvfd)) == -1) { 568 error_f("cannot allocate fds for pty"); 569 if (tmp1 > 0) 570 close(tmp1); 571 if (tmp2 > 0) 572 close(tmp2); 573 return 0; 574 } 575 close(tmp1); 576 close(tmp2); 577 578 if ((m = sshbuf_new()) == NULL) 579 fatal_f("sshbuf_new failed"); 580 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, m); 581 582 debug3_f("waiting for MONITOR_ANS_PTY"); 583 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, m); 584 585 if ((r = sshbuf_get_u32(m, &success)) != 0) 586 fatal_fr(r, "parse success"); 587 if (success == 0) { 588 debug3_f("pty alloc failed"); 589 sshbuf_free(m); 590 return (0); 591 } 592 if ((r = sshbuf_get_cstring(m, &p, NULL)) != 0 || 593 (r = sshbuf_get_cstring(m, &msg, NULL)) != 0) 594 fatal_fr(r, "parse"); 595 sshbuf_free(m); 596 597 strlcpy(namebuf, p, namebuflen); /* Possible truncation */ 598 free(p); 599 600 if ((r = sshbuf_put(loginmsg, msg, strlen(msg))) != 0) 601 fatal_fr(r, "put loginmsg"); 602 free(msg); 603 604 if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 || 605 (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1) 606 fatal_f("receive fds failed"); 607 608 /* Success */ 609 return (1); 610 } 611 612 void 613 mm_session_pty_cleanup2(Session *s) 614 { 615 struct sshbuf *m; 616 int r; 617 618 if (s->ttyfd == -1) 619 return; 620 if ((m = sshbuf_new()) == NULL) 621 fatal_f("sshbuf_new failed"); 622 if ((r = sshbuf_put_cstring(m, s->tty)) != 0) 623 fatal_fr(r, "assmble"); 624 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, m); 625 sshbuf_free(m); 626 627 /* closed dup'ed master */ 628 if (s->ptymaster != -1 && close(s->ptymaster) == -1) 629 error("close(s->ptymaster/%d): %s", 630 s->ptymaster, strerror(errno)); 631 632 /* unlink pty from session */ 633 s->ttyfd = -1; 634 } 635 636 #ifdef USE_PAM 637 void 638 mm_start_pam(struct ssh *ssh) 639 { 640 struct sshbuf *m; 641 642 debug3("%s entering", __func__); 643 if (!options.use_pam) 644 fatal("UsePAM=no, but ended up in %s anyway", __func__); 645 646 if ((m = sshbuf_new()) == NULL) 647 fatal("%s: sshbuf_new failed", __func__); 648 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_START, m); 649 650 sshbuf_free(m); 651 } 652 653 u_int 654 mm_do_pam_account(void) 655 { 656 struct sshbuf *m; 657 int r; 658 u_int ret; 659 size_t len; 660 char *msg; 661 662 debug3("%s entering", __func__); 663 if (!options.use_pam) 664 fatal("UsePAM=no, but ended up in %s anyway", __func__); 665 666 if ((m = sshbuf_new()) == NULL) 667 fatal("%s: sshbuf_new failed", __func__); 668 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_ACCOUNT, m); 669 670 mm_request_receive_expect(pmonitor->m_recvfd, 671 MONITOR_ANS_PAM_ACCOUNT, m); 672 if ((r = sshbuf_get_u32(m, &ret)) != 0 || 673 (r = sshbuf_get_cstring(m, &msg, &len)) != 0) 674 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 675 sshbuf_put_cstring(loginmsg, msg); 676 free(msg); 677 678 sshbuf_free(m); 679 680 debug3("%s returning %d", __func__, ret); 681 682 return (ret); 683 } 684 685 void * 686 mm_sshpam_init_ctx(Authctxt *authctxt) 687 { 688 struct sshbuf *m; 689 u_int success; 690 int r; 691 692 debug3("%s", __func__); 693 if ((m = sshbuf_new()) == NULL) 694 fatal("%s: sshbuf_new failed", __func__); 695 sshbuf_put_cstring(m, authctxt->user); 696 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, m); 697 debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__); 698 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_INIT_CTX, m); 699 if ((r = sshbuf_get_u32(m, &success)) != 0) 700 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 701 if (success == 0) { 702 debug3("%s: pam_init_ctx failed", __func__); 703 sshbuf_free(m); 704 return (NULL); 705 } 706 sshbuf_free(m); 707 return (authctxt); 708 } 709 710 int 711 mm_sshpam_query(void *ctx, char **name, char **info, 712 u_int *num, char ***prompts, u_int **echo_on) 713 { 714 struct sshbuf *m; 715 u_int i, ret; 716 int r; 717 718 debug3("%s", __func__); 719 if ((m = sshbuf_new()) == NULL) 720 fatal("%s: sshbuf_new failed", __func__); 721 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_QUERY, m); 722 debug3("%s: waiting for MONITOR_ANS_PAM_QUERY", __func__); 723 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_QUERY, m); 724 if ((r = sshbuf_get_u32(m, &ret)) != 0) 725 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 726 debug3("%s: pam_query returned %d", __func__, ret); 727 if ((r = sshbuf_get_cstring(m, name, NULL)) != 0 || 728 (r = sshbuf_get_cstring(m, info, NULL)) != 0 || 729 (r = sshbuf_get_u32(m, num)) != 0) 730 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 731 if (*num > PAM_MAX_NUM_MSG) 732 fatal("%s: received %u PAM messages, expected <= %u", 733 __func__, *num, PAM_MAX_NUM_MSG); 734 *prompts = xcalloc((*num + 1), sizeof(char *)); 735 *echo_on = xcalloc((*num + 1), sizeof(u_int)); 736 for (i = 0; i < *num; ++i) { 737 if ((r = sshbuf_get_cstring(m, &(*prompts)[i], NULL)) != 0 || 738 (r = sshbuf_get_u32(m, (echo_on)[i])) != 0) 739 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 740 } 741 sshbuf_free(m); 742 return (ret); 743 } 744 745 int 746 mm_sshpam_respond(void *ctx, u_int num, char **resp) 747 { 748 struct sshbuf *m; 749 int r; 750 u_int i; 751 u_int ret; 752 753 debug3("%s", __func__); 754 if ((m = sshbuf_new()) == NULL) 755 fatal("%s: sshbuf_new failed", __func__); 756 sshbuf_put_u32(m, num); 757 for (i = 0; i < num; ++i) 758 sshbuf_put_cstring(m, resp[i]); 759 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, m); 760 debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__); 761 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_RESPOND, m); 762 if ((r = sshbuf_get_u32(m, &ret)) != 0) 763 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 764 debug3("%s: pam_respond returned %d", __func__, ret); 765 sshbuf_free(m); 766 return (ret); 767 } 768 769 void 770 mm_sshpam_free_ctx(void *ctxtp) 771 { 772 struct sshbuf *m; 773 774 debug3("%s", __func__); 775 if ((m = sshbuf_new()) == NULL) 776 fatal("%s: sshbuf_new failed", __func__); 777 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_FREE_CTX, m); 778 debug3("%s: waiting for MONITOR_ANS_PAM_FREE_CTX", __func__); 779 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_FREE_CTX, m); 780 sshbuf_free(m); 781 } 782 #endif /* USE_PAM */ 783 784 /* Request process termination */ 785 786 void 787 mm_terminate(void) 788 { 789 struct sshbuf *m; 790 791 if ((m = sshbuf_new()) == NULL) 792 fatal_f("sshbuf_new failed"); 793 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, m); 794 sshbuf_free(m); 795 } 796 797 #if defined(BSD_AUTH) || defined(SKEY) 798 static void 799 mm_chall_setup(char **name, char **infotxt, u_int *numprompts, 800 char ***prompts, u_int **echo_on) 801 { 802 *name = xstrdup(""); 803 *infotxt = xstrdup(""); 804 *numprompts = 1; 805 *prompts = xcalloc(*numprompts, sizeof(char *)); 806 *echo_on = xcalloc(*numprompts, sizeof(u_int)); 807 (*echo_on)[0] = 0; 808 } 809 810 #ifdef BSD_AUTH 811 int 812 mm_bsdauth_query(void *ctx, char **name, char **infotxt, 813 u_int *numprompts, char ***prompts, u_int **echo_on) 814 { 815 struct sshbuf *m; 816 u_int success; 817 char *challenge; 818 int r; 819 820 debug3_f("entering"); 821 822 if ((m = sshbuf_new()) == NULL) 823 fatal_f("sshbuf_new failed"); 824 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, m); 825 826 mm_request_receive_expect(pmonitor->m_recvfd, 827 MONITOR_ANS_BSDAUTHQUERY, m); 828 if ((r = sshbuf_get_u32(m, &success)) != 0) 829 fatal_fr(r, "parse success"); 830 if (success == 0) { 831 debug3_f("no challenge"); 832 sshbuf_free(m); 833 return (-1); 834 } 835 836 /* Get the challenge, and format the response */ 837 if ((r = sshbuf_get_cstring(m, &challenge, NULL)) != 0) 838 fatal_fr(r, "parse challenge"); 839 sshbuf_free(m); 840 841 mm_chall_setup(name, infotxt, numprompts, prompts, echo_on); 842 (*prompts)[0] = challenge; 843 844 debug3_f("received challenge: %s", challenge); 845 846 return (0); 847 } 848 849 int 850 mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses) 851 { 852 struct sshbuf *m; 853 int r, authok; 854 855 debug3_f("entering"); 856 if (numresponses != 1) 857 return (-1); 858 859 if ((m = sshbuf_new()) == NULL) 860 fatal_f("sshbuf_new failed"); 861 if ((r = sshbuf_put_cstring(m, responses[0])) != 0) 862 fatal_fr(r, "assemble"); 863 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, m); 864 865 mm_request_receive_expect(pmonitor->m_recvfd, 866 MONITOR_ANS_BSDAUTHRESPOND, m); 867 868 if ((r = sshbuf_get_u32(m, &authok)) != 0) 869 fatal_fr(r, "parse"); 870 sshbuf_free(m); 871 872 return ((authok == 0) ? -1 : 0); 873 } 874 #endif 875 876 #ifdef SKEY 877 int 878 mm_skey_query(void *ctx, char **name, char **infotxt, 879 u_int *numprompts, char ***prompts, u_int **echo_on) 880 { 881 struct sshbuf m; 882 u_int success; 883 char *challenge; 884 885 debug3("%s: entering", __func__); 886 887 sshbuf_new(&m); 888 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYQUERY, &m); 889 890 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SKEYQUERY, 891 &m); 892 success = sshbuf_get_int(&m); 893 if (success == 0) { 894 debug3("%s: no challenge", __func__); 895 sshbuf_free(&m); 896 return (-1); 897 } 898 899 /* Get the challenge, and format the response */ 900 challenge = sshbuf_get_string(&m, NULL); 901 sshbuf_free(&m); 902 903 debug3("%s: received challenge: %s", __func__, challenge); 904 905 mm_chall_setup(name, infotxt, numprompts, prompts, echo_on); 906 907 xasprintf(*prompts, "%s%s", challenge, SKEY_PROMPT); 908 free(challenge); 909 910 return (0); 911 } 912 913 int 914 mm_skey_respond(void *ctx, u_int numresponses, char **responses) 915 { 916 struct sshbuf m; 917 int authok; 918 919 debug3("%s: entering", __func__); 920 if (numresponses != 1) 921 return (-1); 922 923 sshbuf_new(&m); 924 sshbuf_put_cstring(&m, responses[0]); 925 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYRESPOND, &m); 926 927 mm_request_receive_expect(pmonitor->m_recvfd, 928 MONITOR_ANS_SKEYRESPOND, &m); 929 930 authok = sshbuf_get_int(&m); 931 sshbuf_free(&m); 932 933 return ((authok == 0) ? -1 : 0); 934 } 935 #endif /* SKEY */ 936 #endif /* BSDAUTH || SKEY */ 937 938 #ifdef GSSAPI 939 OM_uint32 940 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid) 941 { 942 struct sshbuf *m; 943 OM_uint32 major; 944 int r; 945 946 /* Client doesn't get to see the context */ 947 *ctx = NULL; 948 949 if ((m = sshbuf_new()) == NULL) 950 fatal_f("sshbuf_new failed"); 951 if ((r = sshbuf_put_string(m, goid->elements, goid->length)) != 0) 952 fatal_fr(r, "assemble"); 953 954 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, m); 955 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, m); 956 957 if ((r = sshbuf_get_u32(m, &major)) != 0) 958 fatal_fr(r, "parse"); 959 960 sshbuf_free(m); 961 return (major); 962 } 963 964 OM_uint32 965 mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in, 966 gss_buffer_desc *out, OM_uint32 *flagsp) 967 { 968 struct sshbuf *m; 969 OM_uint32 major; 970 u_int flags; 971 int r; 972 973 if ((m = sshbuf_new()) == NULL) 974 fatal_f("sshbuf_new failed"); 975 if ((r = sshbuf_put_string(m, in->value, in->length)) != 0) 976 fatal_fr(r, "assemble"); 977 978 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, m); 979 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, m); 980 981 if ((r = sshbuf_get_u32(m, &major)) != 0 || 982 (r = ssh_gssapi_get_buffer_desc(m, out)) != 0) 983 fatal_fr(r, "parse"); 984 if (flagsp != NULL) { 985 if ((r = sshbuf_get_u32(m, &flags)) != 0) 986 fatal_fr(r, "parse flags"); 987 *flagsp = flags; 988 } 989 990 sshbuf_free(m); 991 992 return (major); 993 } 994 995 OM_uint32 996 mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic) 997 { 998 struct sshbuf *m; 999 OM_uint32 major; 1000 int r; 1001 1002 if ((m = sshbuf_new()) == NULL) 1003 fatal_f("sshbuf_new failed"); 1004 if ((r = sshbuf_put_string(m, gssbuf->value, gssbuf->length)) != 0 || 1005 (r = sshbuf_put_string(m, gssmic->value, gssmic->length)) != 0) 1006 fatal_fr(r, "assemble"); 1007 1008 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, m); 1009 mm_request_receive_expect(pmonitor->m_recvfd, 1010 MONITOR_ANS_GSSCHECKMIC, m); 1011 1012 if ((r = sshbuf_get_u32(m, &major)) != 0) 1013 fatal_fr(r, "parse"); 1014 sshbuf_free(m); 1015 return(major); 1016 } 1017 1018 int 1019 mm_ssh_gssapi_userok(char *user) 1020 { 1021 struct sshbuf *m; 1022 int r; 1023 u_int authenticated = 0; 1024 1025 if ((m = sshbuf_new()) == NULL) 1026 fatal_f("sshbuf_new failed"); 1027 1028 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, m); 1029 mm_request_receive_expect(pmonitor->m_recvfd, 1030 MONITOR_ANS_GSSUSEROK, m); 1031 1032 if ((r = sshbuf_get_u32(m, &authenticated)) != 0) 1033 fatal_fr(r, "parse"); 1034 1035 sshbuf_free(m); 1036 debug3_f("user %sauthenticated", authenticated ? "" : "not "); 1037 return (authenticated); 1038 } 1039 #endif /* GSSAPI */ 1040 1041 #ifdef KRB5 1042 int 1043 mm_auth_krb5(void *ctx, void *argp, char **userp, void *resp) 1044 { 1045 krb5_data *tkt, *reply; 1046 struct sshbuf *m; 1047 u_int success; 1048 int r; 1049 1050 debug3("%s entering", __func__); 1051 tkt = (krb5_data *) argp; 1052 reply = (krb5_data *) resp; 1053 1054 if ((m = sshbuf_new()) == NULL) 1055 fatal("%s: sshbuf_new failed", __func__); 1056 sshbuf_put_string(m, tkt->data, tkt->length); 1057 1058 mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KRB5, m); 1059 mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KRB5, m); 1060 1061 if ((r = sshbuf_get_u32(m, &success)) != 0) 1062 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1063 if (success) { 1064 size_t len; 1065 u_char *data; 1066 1067 if ((r = sshbuf_get_cstring(m, userp, NULL)) != 0 || 1068 (r = sshbuf_get_string(m, &data, &len)) != 0) 1069 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1070 reply->data = data; 1071 reply->length = len; 1072 } else { 1073 memset(reply, 0, sizeof(*reply)); 1074 *userp = NULL; 1075 } 1076 1077 sshbuf_free(m); 1078 return (success); 1079 } 1080 #endif 1081