1 /* $OpenBSD: clientloop.c,v 1.378 2022/01/22 00:49:34 djm Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * The main loop for the interactive session (client side). 7 * 8 * As far as I am concerned, the code I have written for this software 9 * can be used freely for any purpose. Any derived versions of this 10 * software must be clearly marked as such, and if the derived work is 11 * incompatible with the protocol description in the RFC file, it must be 12 * called by a name other than "ssh" or "Secure Shell". 13 * 14 * 15 * Copyright (c) 1999 Theo de Raadt. All rights reserved. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions 19 * are met: 20 * 1. Redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer. 22 * 2. Redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 * 37 * 38 * SSH2 support added by Markus Friedl. 39 * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved. 40 * 41 * Redistribution and use in source and binary forms, with or without 42 * modification, are permitted provided that the following conditions 43 * are met: 44 * 1. Redistributions of source code must retain the above copyright 45 * notice, this list of conditions and the following disclaimer. 46 * 2. Redistributions in binary form must reproduce the above copyright 47 * notice, this list of conditions and the following disclaimer in the 48 * documentation and/or other materials provided with the distribution. 49 * 50 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 51 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 52 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 53 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 54 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 55 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 56 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 57 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 58 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 59 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 60 */ 61 62 #include "includes.h" 63 64 #include <sys/types.h> 65 #include <sys/ioctl.h> 66 #ifdef HAVE_SYS_STAT_H 67 # include <sys/stat.h> 68 #endif 69 #ifdef HAVE_SYS_TIME_H 70 # include <sys/time.h> 71 #endif 72 #include <sys/socket.h> 73 74 #include <ctype.h> 75 #include <errno.h> 76 #ifdef HAVE_PATHS_H 77 #include <paths.h> 78 #endif 79 #ifdef HAVE_POLL_H 80 #include <poll.h> 81 #endif 82 #include <signal.h> 83 #include <stdio.h> 84 #include <stdlib.h> 85 #include <string.h> 86 #include <stdarg.h> 87 #include <termios.h> 88 #include <pwd.h> 89 #include <unistd.h> 90 #include <limits.h> 91 92 #include "openbsd-compat/sys-queue.h" 93 #include "xmalloc.h" 94 #include "ssh.h" 95 #include "ssh2.h" 96 #include "packet.h" 97 #include "sshbuf.h" 98 #include "compat.h" 99 #include "channels.h" 100 #include "dispatch.h" 101 #include "sshkey.h" 102 #include "cipher.h" 103 #include "kex.h" 104 #include "myproposal.h" 105 #include "log.h" 106 #include "misc.h" 107 #include "readconf.h" 108 #include "clientloop.h" 109 #include "sshconnect.h" 110 #include "authfd.h" 111 #include "atomicio.h" 112 #include "sshpty.h" 113 #include "match.h" 114 #include "msg.h" 115 #include "ssherr.h" 116 #include "hostfile.h" 117 118 /* Permitted RSA signature algorithms for UpdateHostkeys proofs */ 119 #define HOSTKEY_PROOF_RSA_ALGS "rsa-sha2-512,rsa-sha2-256" 120 121 /* import options */ 122 extern Options options; 123 124 /* Control socket */ 125 extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */ 126 127 /* 128 * Name of the host we are connecting to. This is the name given on the 129 * command line, or the Hostname specified for the user-supplied name in a 130 * configuration file. 131 */ 132 extern char *host; 133 134 /* 135 * If this field is not NULL, the ForwardAgent socket is this path and different 136 * instead of SSH_AUTH_SOCK. 137 */ 138 extern char *forward_agent_sock_path; 139 140 /* 141 * Flag to indicate that we have received a window change signal which has 142 * not yet been processed. This will cause a message indicating the new 143 * window size to be sent to the server a little later. This is volatile 144 * because this is updated in a signal handler. 145 */ 146 static volatile sig_atomic_t received_window_change_signal = 0; 147 static volatile sig_atomic_t received_signal = 0; 148 149 /* Time when backgrounded control master using ControlPersist should exit */ 150 static time_t control_persist_exit_time = 0; 151 152 /* Common data for the client loop code. */ 153 volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */ 154 static int last_was_cr; /* Last character was a newline. */ 155 static int exit_status; /* Used to store the command exit status. */ 156 static struct sshbuf *stderr_buffer; /* Used for final exit message. */ 157 static int connection_in; /* Connection to server (input). */ 158 static int connection_out; /* Connection to server (output). */ 159 static int need_rekeying; /* Set to non-zero if rekeying is requested. */ 160 static int session_closed; /* In SSH2: login session closed. */ 161 static u_int x11_refuse_time; /* If >0, refuse x11 opens after this time. */ 162 static time_t server_alive_time; /* Time to do server_alive_check */ 163 164 static void client_init_dispatch(struct ssh *ssh); 165 int session_ident = -1; 166 167 /* Track escape per proto2 channel */ 168 struct escape_filter_ctx { 169 int escape_pending; 170 int escape_char; 171 }; 172 173 /* Context for channel confirmation replies */ 174 struct channel_reply_ctx { 175 const char *request_type; 176 int id; 177 enum confirm_action action; 178 }; 179 180 /* Global request success/failure callbacks */ 181 /* XXX move to struct ssh? */ 182 struct global_confirm { 183 TAILQ_ENTRY(global_confirm) entry; 184 global_confirm_cb *cb; 185 void *ctx; 186 int ref_count; 187 }; 188 TAILQ_HEAD(global_confirms, global_confirm); 189 static struct global_confirms global_confirms = 190 TAILQ_HEAD_INITIALIZER(global_confirms); 191 192 void ssh_process_session2_setup(int, int, int, struct sshbuf *); 193 static void quit_message(const char *fmt, ...) 194 __attribute__((__format__ (printf, 1, 2))); 195 196 static void 197 quit_message(const char *fmt, ...) 198 { 199 char *msg; 200 va_list args; 201 int r; 202 203 va_start(args, fmt); 204 xvasprintf(&msg, fmt, args); 205 va_end(args); 206 207 if ((r = sshbuf_putf(stderr_buffer, "%s\r\n", msg)) != 0) 208 fatal_fr(r, "sshbuf_putf"); 209 quit_pending = 1; 210 } 211 212 /* 213 * Signal handler for the window change signal (SIGWINCH). This just sets a 214 * flag indicating that the window has changed. 215 */ 216 /*ARGSUSED */ 217 static void 218 window_change_handler(int sig) 219 { 220 received_window_change_signal = 1; 221 } 222 223 /* 224 * Signal handler for signals that cause the program to terminate. These 225 * signals must be trapped to restore terminal modes. 226 */ 227 /*ARGSUSED */ 228 static void 229 signal_handler(int sig) 230 { 231 received_signal = sig; 232 quit_pending = 1; 233 } 234 235 /* 236 * Sets control_persist_exit_time to the absolute time when the 237 * backgrounded control master should exit due to expiry of the 238 * ControlPersist timeout. Sets it to 0 if we are not a backgrounded 239 * control master process, or if there is no ControlPersist timeout. 240 */ 241 static void 242 set_control_persist_exit_time(struct ssh *ssh) 243 { 244 if (muxserver_sock == -1 || !options.control_persist 245 || options.control_persist_timeout == 0) { 246 /* not using a ControlPersist timeout */ 247 control_persist_exit_time = 0; 248 } else if (channel_still_open(ssh)) { 249 /* some client connections are still open */ 250 if (control_persist_exit_time > 0) 251 debug2_f("cancel scheduled exit"); 252 control_persist_exit_time = 0; 253 } else if (control_persist_exit_time <= 0) { 254 /* a client connection has recently closed */ 255 control_persist_exit_time = monotime() + 256 (time_t)options.control_persist_timeout; 257 debug2_f("schedule exit in %d seconds", 258 options.control_persist_timeout); 259 } 260 /* else we are already counting down to the timeout */ 261 } 262 263 #define SSH_X11_VALID_DISPLAY_CHARS ":/.-_" 264 static int 265 client_x11_display_valid(const char *display) 266 { 267 size_t i, dlen; 268 269 if (display == NULL) 270 return 0; 271 272 dlen = strlen(display); 273 for (i = 0; i < dlen; i++) { 274 if (!isalnum((u_char)display[i]) && 275 strchr(SSH_X11_VALID_DISPLAY_CHARS, display[i]) == NULL) { 276 debug("Invalid character '%c' in DISPLAY", display[i]); 277 return 0; 278 } 279 } 280 return 1; 281 } 282 283 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1" 284 #define X11_TIMEOUT_SLACK 60 285 int 286 client_x11_get_proto(struct ssh *ssh, const char *display, 287 const char *xauth_path, u_int trusted, u_int timeout, 288 char **_proto, char **_data) 289 { 290 char *cmd, line[512], xdisplay[512]; 291 char xauthfile[PATH_MAX], xauthdir[PATH_MAX]; 292 static char proto[512], data[512]; 293 FILE *f; 294 int got_data = 0, generated = 0, do_unlink = 0, r; 295 struct stat st; 296 u_int now, x11_timeout_real; 297 298 *_proto = proto; 299 *_data = data; 300 proto[0] = data[0] = xauthfile[0] = xauthdir[0] = '\0'; 301 302 if (!client_x11_display_valid(display)) { 303 if (display != NULL) 304 logit("DISPLAY \"%s\" invalid; disabling X11 forwarding", 305 display); 306 return -1; 307 } 308 if (xauth_path != NULL && stat(xauth_path, &st) == -1) { 309 debug("No xauth program."); 310 xauth_path = NULL; 311 } 312 313 if (xauth_path != NULL) { 314 /* 315 * Handle FamilyLocal case where $DISPLAY does 316 * not match an authorization entry. For this we 317 * just try "xauth list unix:displaynum.screennum". 318 * XXX: "localhost" match to determine FamilyLocal 319 * is not perfect. 320 */ 321 if (strncmp(display, "localhost:", 10) == 0) { 322 if ((r = snprintf(xdisplay, sizeof(xdisplay), "unix:%s", 323 display + 10)) < 0 || 324 (size_t)r >= sizeof(xdisplay)) { 325 error_f("display name too long"); 326 return -1; 327 } 328 display = xdisplay; 329 } 330 if (trusted == 0) { 331 /* 332 * Generate an untrusted X11 auth cookie. 333 * 334 * The authentication cookie should briefly outlive 335 * ssh's willingness to forward X11 connections to 336 * avoid nasty fail-open behaviour in the X server. 337 */ 338 mktemp_proto(xauthdir, sizeof(xauthdir)); 339 if (mkdtemp(xauthdir) == NULL) { 340 error_f("mkdtemp: %s", strerror(errno)); 341 return -1; 342 } 343 do_unlink = 1; 344 if ((r = snprintf(xauthfile, sizeof(xauthfile), 345 "%s/xauthfile", xauthdir)) < 0 || 346 (size_t)r >= sizeof(xauthfile)) { 347 error_f("xauthfile path too long"); 348 rmdir(xauthdir); 349 return -1; 350 } 351 352 if (timeout == 0) { 353 /* auth doesn't time out */ 354 xasprintf(&cmd, "%s -f %s generate %s %s " 355 "untrusted 2>%s", 356 xauth_path, xauthfile, display, 357 SSH_X11_PROTO, _PATH_DEVNULL); 358 } else { 359 /* Add some slack to requested expiry */ 360 if (timeout < UINT_MAX - X11_TIMEOUT_SLACK) 361 x11_timeout_real = timeout + 362 X11_TIMEOUT_SLACK; 363 else { 364 /* Don't overflow on long timeouts */ 365 x11_timeout_real = UINT_MAX; 366 } 367 xasprintf(&cmd, "%s -f %s generate %s %s " 368 "untrusted timeout %u 2>%s", 369 xauth_path, xauthfile, display, 370 SSH_X11_PROTO, x11_timeout_real, 371 _PATH_DEVNULL); 372 } 373 debug2_f("xauth command: %s", cmd); 374 375 if (timeout != 0 && x11_refuse_time == 0) { 376 now = monotime() + 1; 377 if (UINT_MAX - timeout < now) 378 x11_refuse_time = UINT_MAX; 379 else 380 x11_refuse_time = now + timeout; 381 channel_set_x11_refuse_time(ssh, 382 x11_refuse_time); 383 } 384 if (system(cmd) == 0) 385 generated = 1; 386 free(cmd); 387 } 388 389 /* 390 * When in untrusted mode, we read the cookie only if it was 391 * successfully generated as an untrusted one in the step 392 * above. 393 */ 394 if (trusted || generated) { 395 xasprintf(&cmd, 396 "%s %s%s list %s 2>" _PATH_DEVNULL, 397 xauth_path, 398 generated ? "-f " : "" , 399 generated ? xauthfile : "", 400 display); 401 debug2("x11_get_proto: %s", cmd); 402 f = popen(cmd, "r"); 403 if (f && fgets(line, sizeof(line), f) && 404 sscanf(line, "%*s %511s %511s", proto, data) == 2) 405 got_data = 1; 406 if (f) 407 pclose(f); 408 free(cmd); 409 } 410 } 411 412 if (do_unlink) { 413 unlink(xauthfile); 414 rmdir(xauthdir); 415 } 416 417 /* Don't fall back to fake X11 data for untrusted forwarding */ 418 if (!trusted && !got_data) { 419 error("Warning: untrusted X11 forwarding setup failed: " 420 "xauth key data not generated"); 421 return -1; 422 } 423 424 /* 425 * If we didn't get authentication data, just make up some 426 * data. The forwarding code will check the validity of the 427 * response anyway, and substitute this data. The X11 428 * server, however, will ignore this fake data and use 429 * whatever authentication mechanisms it was using otherwise 430 * for the local connection. 431 */ 432 if (!got_data) { 433 u_int8_t rnd[16]; 434 u_int i; 435 436 logit("Warning: No xauth data; " 437 "using fake authentication data for X11 forwarding."); 438 strlcpy(proto, SSH_X11_PROTO, sizeof proto); 439 arc4random_buf(rnd, sizeof(rnd)); 440 for (i = 0; i < sizeof(rnd); i++) { 441 snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", 442 rnd[i]); 443 } 444 } 445 446 return 0; 447 } 448 449 /* 450 * Checks if the client window has changed, and sends a packet about it to 451 * the server if so. The actual change is detected elsewhere (by a software 452 * interrupt on Unix); this just checks the flag and sends a message if 453 * appropriate. 454 */ 455 456 static void 457 client_check_window_change(struct ssh *ssh) 458 { 459 if (!received_window_change_signal) 460 return; 461 received_window_change_signal = 0; 462 debug2_f("changed"); 463 channel_send_window_changes(ssh); 464 } 465 466 static int 467 client_global_request_reply(int type, u_int32_t seq, struct ssh *ssh) 468 { 469 struct global_confirm *gc; 470 471 if ((gc = TAILQ_FIRST(&global_confirms)) == NULL) 472 return 0; 473 if (gc->cb != NULL) 474 gc->cb(ssh, type, seq, gc->ctx); 475 if (--gc->ref_count <= 0) { 476 TAILQ_REMOVE(&global_confirms, gc, entry); 477 freezero(gc, sizeof(*gc)); 478 } 479 480 ssh_packet_set_alive_timeouts(ssh, 0); 481 return 0; 482 } 483 484 static void 485 schedule_server_alive_check(void) 486 { 487 if (options.server_alive_interval > 0) 488 server_alive_time = monotime() + options.server_alive_interval; 489 } 490 491 static void 492 server_alive_check(struct ssh *ssh) 493 { 494 int r; 495 496 if (ssh_packet_inc_alive_timeouts(ssh) > options.server_alive_count_max) { 497 logit("Timeout, server %s not responding.", host); 498 cleanup_exit(255); 499 } 500 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || 501 (r = sshpkt_put_cstring(ssh, "keepalive@openssh.com")) != 0 || 502 (r = sshpkt_put_u8(ssh, 1)) != 0 || /* boolean: want reply */ 503 (r = sshpkt_send(ssh)) != 0) 504 fatal_fr(r, "send packet"); 505 /* Insert an empty placeholder to maintain ordering */ 506 client_register_global_confirm(NULL, NULL); 507 schedule_server_alive_check(); 508 } 509 510 /* 511 * Waits until the client can do something (some data becomes available on 512 * one of the file descriptors). 513 */ 514 static void 515 client_wait_until_can_do_something(struct ssh *ssh, struct pollfd **pfdp, 516 u_int *npfd_allocp, u_int *npfd_activep, int rekeying, 517 int *conn_in_readyp, int *conn_out_readyp) 518 { 519 int timeout_secs, pollwait; 520 time_t minwait_secs = 0, now = monotime(); 521 int ret; 522 u_int p; 523 524 *conn_in_readyp = *conn_out_readyp = 0; 525 526 /* Prepare channel poll. First two pollfd entries are reserved */ 527 channel_prepare_poll(ssh, pfdp, npfd_allocp, npfd_activep, 2, 528 &minwait_secs); 529 if (*npfd_activep < 2) 530 fatal_f("bad npfd %u", *npfd_activep); /* shouldn't happen */ 531 532 /* channel_prepare_poll could have closed the last channel */ 533 if (session_closed && !channel_still_open(ssh) && 534 !ssh_packet_have_data_to_write(ssh)) { 535 /* clear events since we did not call poll() */ 536 for (p = 0; p < *npfd_activep; p++) 537 (*pfdp)[p].revents = 0; 538 return; 539 } 540 541 /* Monitor server connection on reserved pollfd entries */ 542 (*pfdp)[0].fd = connection_in; 543 (*pfdp)[0].events = POLLIN; 544 (*pfdp)[1].fd = connection_out; 545 (*pfdp)[1].events = ssh_packet_have_data_to_write(ssh) ? POLLOUT : 0; 546 547 /* 548 * Wait for something to happen. This will suspend the process until 549 * some polled descriptor can be read, written, or has some other 550 * event pending, or a timeout expires. 551 */ 552 553 timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */ 554 if (options.server_alive_interval > 0) 555 timeout_secs = MAXIMUM(server_alive_time - now, 0); 556 if (options.rekey_interval > 0 && !rekeying) 557 timeout_secs = MINIMUM(timeout_secs, 558 ssh_packet_get_rekey_timeout(ssh)); 559 set_control_persist_exit_time(ssh); 560 if (control_persist_exit_time > 0) { 561 timeout_secs = MINIMUM(timeout_secs, 562 control_persist_exit_time - now); 563 if (timeout_secs < 0) 564 timeout_secs = 0; 565 } 566 if (minwait_secs != 0) 567 timeout_secs = MINIMUM(timeout_secs, (int)minwait_secs); 568 if (timeout_secs == INT_MAX) 569 pollwait = -1; 570 else if (timeout_secs >= INT_MAX / 1000) 571 pollwait = INT_MAX; 572 else 573 pollwait = timeout_secs * 1000; 574 575 ret = poll(*pfdp, *npfd_activep, pollwait); 576 577 if (ret == -1) { 578 /* 579 * We have to clear the events because we return. 580 * We have to return, because the mainloop checks for the flags 581 * set by the signal handlers. 582 */ 583 for (p = 0; p < *npfd_activep; p++) 584 (*pfdp)[p].revents = 0; 585 if (errno == EINTR) 586 return; 587 /* Note: we might still have data in the buffers. */ 588 quit_message("poll: %s", strerror(errno)); 589 return; 590 } 591 592 *conn_in_readyp = (*pfdp)[0].revents != 0; 593 *conn_out_readyp = (*pfdp)[1].revents != 0; 594 595 if (options.server_alive_interval > 0 && !*conn_in_readyp && 596 monotime() >= server_alive_time) { 597 /* 598 * ServerAlive check is needed. We can't rely on the poll 599 * timing out since traffic on the client side such as port 600 * forwards can keep waking it up. 601 */ 602 server_alive_check(ssh); 603 } 604 } 605 606 static void 607 client_suspend_self(struct sshbuf *bin, struct sshbuf *bout, struct sshbuf *berr) 608 { 609 /* Flush stdout and stderr buffers. */ 610 if (sshbuf_len(bout) > 0) 611 atomicio(vwrite, fileno(stdout), sshbuf_mutable_ptr(bout), 612 sshbuf_len(bout)); 613 if (sshbuf_len(berr) > 0) 614 atomicio(vwrite, fileno(stderr), sshbuf_mutable_ptr(berr), 615 sshbuf_len(berr)); 616 617 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 618 619 sshbuf_reset(bin); 620 sshbuf_reset(bout); 621 sshbuf_reset(berr); 622 623 /* Send the suspend signal to the program itself. */ 624 kill(getpid(), SIGTSTP); 625 626 /* Reset window sizes in case they have changed */ 627 received_window_change_signal = 1; 628 629 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 630 } 631 632 static void 633 client_process_net_input(struct ssh *ssh) 634 { 635 int r; 636 637 /* 638 * Read input from the server, and add any such data to the buffer of 639 * the packet subsystem. 640 */ 641 schedule_server_alive_check(); 642 if ((r = ssh_packet_process_read(ssh, connection_in)) == 0) 643 return; /* success */ 644 if (r == SSH_ERR_SYSTEM_ERROR) { 645 if (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK) 646 return; 647 if (errno == EPIPE) { 648 quit_message("Connection to %s closed by remote host.", 649 host); 650 return; 651 } 652 } 653 quit_message("Read from remote host %s: %s", host, ssh_err(r)); 654 } 655 656 static void 657 client_status_confirm(struct ssh *ssh, int type, Channel *c, void *ctx) 658 { 659 struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx; 660 char errmsg[256]; 661 int r, tochan; 662 663 /* 664 * If a TTY was explicitly requested, then a failure to allocate 665 * one is fatal. 666 */ 667 if (cr->action == CONFIRM_TTY && 668 (options.request_tty == REQUEST_TTY_FORCE || 669 options.request_tty == REQUEST_TTY_YES)) 670 cr->action = CONFIRM_CLOSE; 671 672 /* XXX suppress on mux _client_ quietmode */ 673 tochan = options.log_level >= SYSLOG_LEVEL_ERROR && 674 c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE; 675 676 if (type == SSH2_MSG_CHANNEL_SUCCESS) { 677 debug2("%s request accepted on channel %d", 678 cr->request_type, c->self); 679 } else if (type == SSH2_MSG_CHANNEL_FAILURE) { 680 if (tochan) { 681 snprintf(errmsg, sizeof(errmsg), 682 "%s request failed\r\n", cr->request_type); 683 } else { 684 snprintf(errmsg, sizeof(errmsg), 685 "%s request failed on channel %d", 686 cr->request_type, c->self); 687 } 688 /* If error occurred on primary session channel, then exit */ 689 if (cr->action == CONFIRM_CLOSE && c->self == session_ident) 690 fatal("%s", errmsg); 691 /* 692 * If error occurred on mux client, append to 693 * their stderr. 694 */ 695 if (tochan) { 696 debug3_f("channel %d: mux request: %s", c->self, 697 cr->request_type); 698 if ((r = sshbuf_put(c->extended, errmsg, 699 strlen(errmsg))) != 0) 700 fatal_fr(r, "sshbuf_put"); 701 } else 702 error("%s", errmsg); 703 if (cr->action == CONFIRM_TTY) { 704 /* 705 * If a TTY allocation error occurred, then arrange 706 * for the correct TTY to leave raw mode. 707 */ 708 if (c->self == session_ident) 709 leave_raw_mode(0); 710 else 711 mux_tty_alloc_failed(ssh, c); 712 } else if (cr->action == CONFIRM_CLOSE) { 713 chan_read_failed(ssh, c); 714 chan_write_failed(ssh, c); 715 } 716 } 717 free(cr); 718 } 719 720 static void 721 client_abandon_status_confirm(struct ssh *ssh, Channel *c, void *ctx) 722 { 723 free(ctx); 724 } 725 726 void 727 client_expect_confirm(struct ssh *ssh, int id, const char *request, 728 enum confirm_action action) 729 { 730 struct channel_reply_ctx *cr = xcalloc(1, sizeof(*cr)); 731 732 cr->request_type = request; 733 cr->action = action; 734 735 channel_register_status_confirm(ssh, id, client_status_confirm, 736 client_abandon_status_confirm, cr); 737 } 738 739 void 740 client_register_global_confirm(global_confirm_cb *cb, void *ctx) 741 { 742 struct global_confirm *gc, *last_gc; 743 744 /* Coalesce identical callbacks */ 745 last_gc = TAILQ_LAST(&global_confirms, global_confirms); 746 if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) { 747 if (++last_gc->ref_count >= INT_MAX) 748 fatal_f("last_gc->ref_count = %d", 749 last_gc->ref_count); 750 return; 751 } 752 753 gc = xcalloc(1, sizeof(*gc)); 754 gc->cb = cb; 755 gc->ctx = ctx; 756 gc->ref_count = 1; 757 TAILQ_INSERT_TAIL(&global_confirms, gc, entry); 758 } 759 760 static void 761 process_cmdline(struct ssh *ssh) 762 { 763 void (*handler)(int); 764 char *s, *cmd; 765 int ok, delete = 0, local = 0, remote = 0, dynamic = 0; 766 struct Forward fwd; 767 768 memset(&fwd, 0, sizeof(fwd)); 769 770 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 771 handler = ssh_signal(SIGINT, SIG_IGN); 772 cmd = s = read_passphrase("\r\nssh> ", RP_ECHO); 773 if (s == NULL) 774 goto out; 775 while (isspace((u_char)*s)) 776 s++; 777 if (*s == '-') 778 s++; /* Skip cmdline '-', if any */ 779 if (*s == '\0') 780 goto out; 781 782 if (*s == 'h' || *s == 'H' || *s == '?') { 783 logit("Commands:"); 784 logit(" -L[bind_address:]port:host:hostport " 785 "Request local forward"); 786 logit(" -R[bind_address:]port:host:hostport " 787 "Request remote forward"); 788 logit(" -D[bind_address:]port " 789 "Request dynamic forward"); 790 logit(" -KL[bind_address:]port " 791 "Cancel local forward"); 792 logit(" -KR[bind_address:]port " 793 "Cancel remote forward"); 794 logit(" -KD[bind_address:]port " 795 "Cancel dynamic forward"); 796 if (!options.permit_local_command) 797 goto out; 798 logit(" !args " 799 "Execute local command"); 800 goto out; 801 } 802 803 if (*s == '!' && options.permit_local_command) { 804 s++; 805 ssh_local_cmd(s); 806 goto out; 807 } 808 809 if (*s == 'K') { 810 delete = 1; 811 s++; 812 } 813 if (*s == 'L') 814 local = 1; 815 else if (*s == 'R') 816 remote = 1; 817 else if (*s == 'D') 818 dynamic = 1; 819 else { 820 logit("Invalid command."); 821 goto out; 822 } 823 824 while (isspace((u_char)*++s)) 825 ; 826 827 /* XXX update list of forwards in options */ 828 if (delete) { 829 /* We pass 1 for dynamicfwd to restrict to 1 or 2 fields. */ 830 if (!parse_forward(&fwd, s, 1, 0)) { 831 logit("Bad forwarding close specification."); 832 goto out; 833 } 834 if (remote) 835 ok = channel_request_rforward_cancel(ssh, &fwd) == 0; 836 else if (dynamic) 837 ok = channel_cancel_lport_listener(ssh, &fwd, 838 0, &options.fwd_opts) > 0; 839 else 840 ok = channel_cancel_lport_listener(ssh, &fwd, 841 CHANNEL_CANCEL_PORT_STATIC, 842 &options.fwd_opts) > 0; 843 if (!ok) { 844 logit("Unknown port forwarding."); 845 goto out; 846 } 847 logit("Canceled forwarding."); 848 } else { 849 if (!parse_forward(&fwd, s, dynamic, remote)) { 850 logit("Bad forwarding specification."); 851 goto out; 852 } 853 if (local || dynamic) { 854 if (!channel_setup_local_fwd_listener(ssh, &fwd, 855 &options.fwd_opts)) { 856 logit("Port forwarding failed."); 857 goto out; 858 } 859 } else { 860 if (channel_request_remote_forwarding(ssh, &fwd) < 0) { 861 logit("Port forwarding failed."); 862 goto out; 863 } 864 } 865 logit("Forwarding port."); 866 } 867 868 out: 869 ssh_signal(SIGINT, handler); 870 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 871 free(cmd); 872 free(fwd.listen_host); 873 free(fwd.listen_path); 874 free(fwd.connect_host); 875 free(fwd.connect_path); 876 } 877 878 /* reasons to suppress output of an escape command in help output */ 879 #define SUPPRESS_NEVER 0 /* never suppress, always show */ 880 #define SUPPRESS_MUXCLIENT 1 /* don't show in mux client sessions */ 881 #define SUPPRESS_MUXMASTER 2 /* don't show in mux master sessions */ 882 #define SUPPRESS_SYSLOG 4 /* don't show when logging to syslog */ 883 struct escape_help_text { 884 const char *cmd; 885 const char *text; 886 unsigned int flags; 887 }; 888 static struct escape_help_text esc_txt[] = { 889 {".", "terminate session", SUPPRESS_MUXMASTER}, 890 {".", "terminate connection (and any multiplexed sessions)", 891 SUPPRESS_MUXCLIENT}, 892 {"B", "send a BREAK to the remote system", SUPPRESS_NEVER}, 893 {"C", "open a command line", SUPPRESS_MUXCLIENT}, 894 {"R", "request rekey", SUPPRESS_NEVER}, 895 {"V/v", "decrease/increase verbosity (LogLevel)", SUPPRESS_MUXCLIENT}, 896 {"^Z", "suspend ssh", SUPPRESS_MUXCLIENT}, 897 {"#", "list forwarded connections", SUPPRESS_NEVER}, 898 {"&", "background ssh (when waiting for connections to terminate)", 899 SUPPRESS_MUXCLIENT}, 900 {"?", "this message", SUPPRESS_NEVER}, 901 }; 902 903 static void 904 print_escape_help(struct sshbuf *b, int escape_char, int mux_client, 905 int using_stderr) 906 { 907 unsigned int i, suppress_flags; 908 int r; 909 910 if ((r = sshbuf_putf(b, 911 "%c?\r\nSupported escape sequences:\r\n", escape_char)) != 0) 912 fatal_fr(r, "sshbuf_putf"); 913 914 suppress_flags = 915 (mux_client ? SUPPRESS_MUXCLIENT : 0) | 916 (mux_client ? 0 : SUPPRESS_MUXMASTER) | 917 (using_stderr ? 0 : SUPPRESS_SYSLOG); 918 919 for (i = 0; i < sizeof(esc_txt)/sizeof(esc_txt[0]); i++) { 920 if (esc_txt[i].flags & suppress_flags) 921 continue; 922 if ((r = sshbuf_putf(b, " %c%-3s - %s\r\n", 923 escape_char, esc_txt[i].cmd, esc_txt[i].text)) != 0) 924 fatal_fr(r, "sshbuf_putf"); 925 } 926 927 if ((r = sshbuf_putf(b, 928 " %c%c - send the escape character by typing it twice\r\n" 929 "(Note that escapes are only recognized immediately after " 930 "newline.)\r\n", escape_char, escape_char)) != 0) 931 fatal_fr(r, "sshbuf_putf"); 932 } 933 934 /* 935 * Process the characters one by one. 936 */ 937 static int 938 process_escapes(struct ssh *ssh, Channel *c, 939 struct sshbuf *bin, struct sshbuf *bout, struct sshbuf *berr, 940 char *buf, int len) 941 { 942 pid_t pid; 943 int r, bytes = 0; 944 u_int i; 945 u_char ch; 946 char *s; 947 struct escape_filter_ctx *efc = c->filter_ctx == NULL ? 948 NULL : (struct escape_filter_ctx *)c->filter_ctx; 949 950 if (c->filter_ctx == NULL) 951 return 0; 952 953 if (len <= 0) 954 return (0); 955 956 for (i = 0; i < (u_int)len; i++) { 957 /* Get one character at a time. */ 958 ch = buf[i]; 959 960 if (efc->escape_pending) { 961 /* We have previously seen an escape character. */ 962 /* Clear the flag now. */ 963 efc->escape_pending = 0; 964 965 /* Process the escaped character. */ 966 switch (ch) { 967 case '.': 968 /* Terminate the connection. */ 969 if ((r = sshbuf_putf(berr, "%c.\r\n", 970 efc->escape_char)) != 0) 971 fatal_fr(r, "sshbuf_putf"); 972 if (c && c->ctl_chan != -1) { 973 chan_read_failed(ssh, c); 974 chan_write_failed(ssh, c); 975 if (c->detach_user) { 976 c->detach_user(ssh, 977 c->self, NULL); 978 } 979 c->type = SSH_CHANNEL_ABANDONED; 980 sshbuf_reset(c->input); 981 chan_ibuf_empty(ssh, c); 982 return 0; 983 } else 984 quit_pending = 1; 985 return -1; 986 987 case 'Z' - 64: 988 /* XXX support this for mux clients */ 989 if (c && c->ctl_chan != -1) { 990 char b[16]; 991 noescape: 992 if (ch == 'Z' - 64) 993 snprintf(b, sizeof b, "^Z"); 994 else 995 snprintf(b, sizeof b, "%c", ch); 996 if ((r = sshbuf_putf(berr, 997 "%c%s escape not available to " 998 "multiplexed sessions\r\n", 999 efc->escape_char, b)) != 0) 1000 fatal_fr(r, "sshbuf_putf"); 1001 continue; 1002 } 1003 /* Suspend the program. Inform the user */ 1004 if ((r = sshbuf_putf(berr, 1005 "%c^Z [suspend ssh]\r\n", 1006 efc->escape_char)) != 0) 1007 fatal_fr(r, "sshbuf_putf"); 1008 1009 /* Restore terminal modes and suspend. */ 1010 client_suspend_self(bin, bout, berr); 1011 1012 /* We have been continued. */ 1013 continue; 1014 1015 case 'B': 1016 if ((r = sshbuf_putf(berr, 1017 "%cB\r\n", efc->escape_char)) != 0) 1018 fatal_fr(r, "sshbuf_putf"); 1019 channel_request_start(ssh, c->self, "break", 0); 1020 if ((r = sshpkt_put_u32(ssh, 1000)) != 0 || 1021 (r = sshpkt_send(ssh)) != 0) 1022 fatal_fr(r, "send packet"); 1023 continue; 1024 1025 case 'R': 1026 if (ssh->compat & SSH_BUG_NOREKEY) 1027 logit("Server does not " 1028 "support re-keying"); 1029 else 1030 need_rekeying = 1; 1031 continue; 1032 1033 case 'V': 1034 /* FALLTHROUGH */ 1035 case 'v': 1036 if (c && c->ctl_chan != -1) 1037 goto noescape; 1038 if (!log_is_on_stderr()) { 1039 if ((r = sshbuf_putf(berr, 1040 "%c%c [Logging to syslog]\r\n", 1041 efc->escape_char, ch)) != 0) 1042 fatal_fr(r, "sshbuf_putf"); 1043 continue; 1044 } 1045 if (ch == 'V' && options.log_level > 1046 SYSLOG_LEVEL_QUIET) 1047 log_change_level(--options.log_level); 1048 if (ch == 'v' && options.log_level < 1049 SYSLOG_LEVEL_DEBUG3) 1050 log_change_level(++options.log_level); 1051 if ((r = sshbuf_putf(berr, 1052 "%c%c [LogLevel %s]\r\n", 1053 efc->escape_char, ch, 1054 log_level_name(options.log_level))) != 0) 1055 fatal_fr(r, "sshbuf_putf"); 1056 continue; 1057 1058 case '&': 1059 if (c && c->ctl_chan != -1) 1060 goto noescape; 1061 /* 1062 * Detach the program (continue to serve 1063 * connections, but put in background and no 1064 * more new connections). 1065 */ 1066 /* Restore tty modes. */ 1067 leave_raw_mode( 1068 options.request_tty == REQUEST_TTY_FORCE); 1069 1070 /* Stop listening for new connections. */ 1071 channel_stop_listening(ssh); 1072 1073 if ((r = sshbuf_putf(berr, "%c& " 1074 "[backgrounded]\n", efc->escape_char)) != 0) 1075 fatal_fr(r, "sshbuf_putf"); 1076 1077 /* Fork into background. */ 1078 pid = fork(); 1079 if (pid == -1) { 1080 error("fork: %.100s", strerror(errno)); 1081 continue; 1082 } 1083 if (pid != 0) { /* This is the parent. */ 1084 /* The parent just exits. */ 1085 exit(0); 1086 } 1087 /* The child continues serving connections. */ 1088 /* fake EOF on stdin */ 1089 if ((r = sshbuf_put_u8(bin, 4)) != 0) 1090 fatal_fr(r, "sshbuf_put_u8"); 1091 return -1; 1092 case '?': 1093 print_escape_help(berr, efc->escape_char, 1094 (c && c->ctl_chan != -1), 1095 log_is_on_stderr()); 1096 continue; 1097 1098 case '#': 1099 if ((r = sshbuf_putf(berr, "%c#\r\n", 1100 efc->escape_char)) != 0) 1101 fatal_fr(r, "sshbuf_putf"); 1102 s = channel_open_message(ssh); 1103 if ((r = sshbuf_put(berr, s, strlen(s))) != 0) 1104 fatal_fr(r, "sshbuf_put"); 1105 free(s); 1106 continue; 1107 1108 case 'C': 1109 if (c && c->ctl_chan != -1) 1110 goto noescape; 1111 process_cmdline(ssh); 1112 continue; 1113 1114 default: 1115 if (ch != efc->escape_char) { 1116 if ((r = sshbuf_put_u8(bin, 1117 efc->escape_char)) != 0) 1118 fatal_fr(r, "sshbuf_put_u8"); 1119 bytes++; 1120 } 1121 /* Escaped characters fall through here */ 1122 break; 1123 } 1124 } else { 1125 /* 1126 * The previous character was not an escape char. 1127 * Check if this is an escape. 1128 */ 1129 if (last_was_cr && ch == efc->escape_char) { 1130 /* 1131 * It is. Set the flag and continue to 1132 * next character. 1133 */ 1134 efc->escape_pending = 1; 1135 continue; 1136 } 1137 } 1138 1139 /* 1140 * Normal character. Record whether it was a newline, 1141 * and append it to the buffer. 1142 */ 1143 last_was_cr = (ch == '\r' || ch == '\n'); 1144 if ((r = sshbuf_put_u8(bin, ch)) != 0) 1145 fatal_fr(r, "sshbuf_put_u8"); 1146 bytes++; 1147 } 1148 return bytes; 1149 } 1150 1151 /* 1152 * Get packets from the connection input buffer, and process them as long as 1153 * there are packets available. 1154 * 1155 * Any unknown packets received during the actual 1156 * session cause the session to terminate. This is 1157 * intended to make debugging easier since no 1158 * confirmations are sent. Any compatible protocol 1159 * extensions must be negotiated during the 1160 * preparatory phase. 1161 */ 1162 1163 static void 1164 client_process_buffered_input_packets(struct ssh *ssh) 1165 { 1166 ssh_dispatch_run_fatal(ssh, DISPATCH_NONBLOCK, &quit_pending); 1167 } 1168 1169 /* scan buf[] for '~' before sending data to the peer */ 1170 1171 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */ 1172 void * 1173 client_new_escape_filter_ctx(int escape_char) 1174 { 1175 struct escape_filter_ctx *ret; 1176 1177 ret = xcalloc(1, sizeof(*ret)); 1178 ret->escape_pending = 0; 1179 ret->escape_char = escape_char; 1180 return (void *)ret; 1181 } 1182 1183 /* Free the escape filter context on channel free */ 1184 void 1185 client_filter_cleanup(struct ssh *ssh, int cid, void *ctx) 1186 { 1187 free(ctx); 1188 } 1189 1190 int 1191 client_simple_escape_filter(struct ssh *ssh, Channel *c, char *buf, int len) 1192 { 1193 if (c->extended_usage != CHAN_EXTENDED_WRITE) 1194 return 0; 1195 1196 return process_escapes(ssh, c, c->input, c->output, c->extended, 1197 buf, len); 1198 } 1199 1200 static void 1201 client_channel_closed(struct ssh *ssh, int id, void *arg) 1202 { 1203 channel_cancel_cleanup(ssh, id); 1204 session_closed = 1; 1205 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1206 } 1207 1208 /* 1209 * Implements the interactive session with the server. This is called after 1210 * the user has been authenticated, and a command has been started on the 1211 * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character 1212 * used as an escape character for terminating or suspending the session. 1213 */ 1214 int 1215 client_loop(struct ssh *ssh, int have_pty, int escape_char_arg, 1216 int ssh2_chan_id) 1217 { 1218 struct pollfd *pfd = NULL; 1219 u_int npfd_alloc = 0, npfd_active = 0; 1220 double start_time, total_time; 1221 int r, len; 1222 u_int64_t ibytes, obytes; 1223 int conn_in_ready, conn_out_ready; 1224 1225 debug("Entering interactive session."); 1226 1227 if (options.control_master && 1228 !option_clear_or_none(options.control_path)) { 1229 debug("pledge: id"); 1230 if (pledge("stdio rpath wpath cpath unix inet dns recvfd sendfd proc exec id tty", 1231 NULL) == -1) 1232 fatal_f("pledge(): %s", strerror(errno)); 1233 1234 } else if (options.forward_x11 || options.permit_local_command) { 1235 debug("pledge: exec"); 1236 if (pledge("stdio rpath wpath cpath unix inet dns proc exec tty", 1237 NULL) == -1) 1238 fatal_f("pledge(): %s", strerror(errno)); 1239 1240 } else if (options.update_hostkeys) { 1241 debug("pledge: filesystem"); 1242 if (pledge("stdio rpath wpath cpath unix inet dns proc tty", 1243 NULL) == -1) 1244 fatal_f("pledge(): %s", strerror(errno)); 1245 1246 } else if (!option_clear_or_none(options.proxy_command) || 1247 options.fork_after_authentication) { 1248 debug("pledge: proc"); 1249 if (pledge("stdio cpath unix inet dns proc tty", NULL) == -1) 1250 fatal_f("pledge(): %s", strerror(errno)); 1251 1252 } else { 1253 debug("pledge: network"); 1254 if (pledge("stdio unix inet dns proc tty", NULL) == -1) 1255 fatal_f("pledge(): %s", strerror(errno)); 1256 } 1257 1258 start_time = monotime_double(); 1259 1260 /* Initialize variables. */ 1261 last_was_cr = 1; 1262 exit_status = -1; 1263 connection_in = ssh_packet_get_connection_in(ssh); 1264 connection_out = ssh_packet_get_connection_out(ssh); 1265 1266 quit_pending = 0; 1267 1268 /* Initialize buffer. */ 1269 if ((stderr_buffer = sshbuf_new()) == NULL) 1270 fatal_f("sshbuf_new failed"); 1271 1272 client_init_dispatch(ssh); 1273 1274 /* 1275 * Set signal handlers, (e.g. to restore non-blocking mode) 1276 * but don't overwrite SIG_IGN, matches behaviour from rsh(1) 1277 */ 1278 if (ssh_signal(SIGHUP, SIG_IGN) != SIG_IGN) 1279 ssh_signal(SIGHUP, signal_handler); 1280 if (ssh_signal(SIGINT, SIG_IGN) != SIG_IGN) 1281 ssh_signal(SIGINT, signal_handler); 1282 if (ssh_signal(SIGQUIT, SIG_IGN) != SIG_IGN) 1283 ssh_signal(SIGQUIT, signal_handler); 1284 if (ssh_signal(SIGTERM, SIG_IGN) != SIG_IGN) 1285 ssh_signal(SIGTERM, signal_handler); 1286 ssh_signal(SIGWINCH, window_change_handler); 1287 1288 if (have_pty) 1289 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1290 1291 session_ident = ssh2_chan_id; 1292 if (session_ident != -1) { 1293 if (escape_char_arg != SSH_ESCAPECHAR_NONE) { 1294 channel_register_filter(ssh, session_ident, 1295 client_simple_escape_filter, NULL, 1296 client_filter_cleanup, 1297 client_new_escape_filter_ctx( 1298 escape_char_arg)); 1299 } 1300 channel_register_cleanup(ssh, session_ident, 1301 client_channel_closed, 0); 1302 } 1303 1304 schedule_server_alive_check(); 1305 1306 /* Main loop of the client for the interactive session mode. */ 1307 while (!quit_pending) { 1308 1309 /* Process buffered packets sent by the server. */ 1310 client_process_buffered_input_packets(ssh); 1311 1312 if (session_closed && !channel_still_open(ssh)) 1313 break; 1314 1315 if (ssh_packet_is_rekeying(ssh)) { 1316 debug("rekeying in progress"); 1317 } else if (need_rekeying) { 1318 /* manual rekey request */ 1319 debug("need rekeying"); 1320 if ((r = kex_start_rekex(ssh)) != 0) 1321 fatal_fr(r, "kex_start_rekex"); 1322 need_rekeying = 0; 1323 } else { 1324 /* 1325 * Make packets from buffered channel data, and 1326 * enqueue them for sending to the server. 1327 */ 1328 if (ssh_packet_not_very_much_data_to_write(ssh)) 1329 channel_output_poll(ssh); 1330 1331 /* 1332 * Check if the window size has changed, and buffer a 1333 * message about it to the server if so. 1334 */ 1335 client_check_window_change(ssh); 1336 1337 if (quit_pending) 1338 break; 1339 } 1340 /* 1341 * Wait until we have something to do (something becomes 1342 * available on one of the descriptors). 1343 */ 1344 client_wait_until_can_do_something(ssh, &pfd, &npfd_alloc, 1345 &npfd_active, ssh_packet_is_rekeying(ssh), 1346 &conn_in_ready, &conn_out_ready); 1347 1348 if (quit_pending) 1349 break; 1350 1351 /* Do channel operations unless rekeying in progress. */ 1352 if (!ssh_packet_is_rekeying(ssh)) 1353 channel_after_poll(ssh, pfd, npfd_active); 1354 1355 /* Buffer input from the connection. */ 1356 if (conn_in_ready) 1357 client_process_net_input(ssh); 1358 1359 if (quit_pending) 1360 break; 1361 1362 /* A timeout may have triggered rekeying */ 1363 if ((r = ssh_packet_check_rekey(ssh)) != 0) 1364 fatal_fr(r, "cannot start rekeying"); 1365 1366 /* 1367 * Send as much buffered packet data as possible to the 1368 * sender. 1369 */ 1370 if (conn_out_ready) { 1371 if ((r = ssh_packet_write_poll(ssh)) != 0) { 1372 sshpkt_fatal(ssh, r, 1373 "%s: ssh_packet_write_poll", __func__); 1374 } 1375 } 1376 1377 /* 1378 * If we are a backgrounded control master, and the 1379 * timeout has expired without any active client 1380 * connections, then quit. 1381 */ 1382 if (control_persist_exit_time > 0) { 1383 if (monotime() >= control_persist_exit_time) { 1384 debug("ControlPersist timeout expired"); 1385 break; 1386 } 1387 } 1388 } 1389 free(pfd); 1390 1391 /* Terminate the session. */ 1392 1393 /* Stop watching for window change. */ 1394 ssh_signal(SIGWINCH, SIG_DFL); 1395 1396 if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 || 1397 (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_BY_APPLICATION)) != 0 || 1398 (r = sshpkt_put_cstring(ssh, "disconnected by user")) != 0 || 1399 (r = sshpkt_put_cstring(ssh, "")) != 0 || /* language tag */ 1400 (r = sshpkt_send(ssh)) != 0 || 1401 (r = ssh_packet_write_wait(ssh)) != 0) 1402 fatal_fr(r, "send disconnect"); 1403 1404 channel_free_all(ssh); 1405 1406 if (have_pty) 1407 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1408 1409 /* 1410 * If there was no shell or command requested, there will be no remote 1411 * exit status to be returned. In that case, clear error code if the 1412 * connection was deliberately terminated at this end. 1413 */ 1414 if (options.session_type == SESSION_TYPE_NONE && 1415 received_signal == SIGTERM) { 1416 received_signal = 0; 1417 exit_status = 0; 1418 } 1419 1420 if (received_signal) { 1421 verbose("Killed by signal %d.", (int) received_signal); 1422 cleanup_exit(255); 1423 } 1424 1425 /* 1426 * In interactive mode (with pseudo tty) display a message indicating 1427 * that the connection has been closed. 1428 */ 1429 if (have_pty && options.log_level >= SYSLOG_LEVEL_INFO) 1430 quit_message("Connection to %s closed.", host); 1431 1432 /* Output any buffered data for stderr. */ 1433 if (sshbuf_len(stderr_buffer) > 0) { 1434 len = atomicio(vwrite, fileno(stderr), 1435 (u_char *)sshbuf_ptr(stderr_buffer), 1436 sshbuf_len(stderr_buffer)); 1437 if (len < 0 || (u_int)len != sshbuf_len(stderr_buffer)) 1438 error("Write failed flushing stderr buffer."); 1439 else if ((r = sshbuf_consume(stderr_buffer, len)) != 0) 1440 fatal_fr(r, "sshbuf_consume"); 1441 } 1442 1443 /* Clear and free any buffers. */ 1444 sshbuf_free(stderr_buffer); 1445 1446 /* Report bytes transferred, and transfer rates. */ 1447 total_time = monotime_double() - start_time; 1448 ssh_packet_get_bytes(ssh, &ibytes, &obytes); 1449 verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds", 1450 (unsigned long long)obytes, (unsigned long long)ibytes, total_time); 1451 if (total_time > 0) 1452 verbose("Bytes per second: sent %.1f, received %.1f", 1453 obytes / total_time, ibytes / total_time); 1454 /* Return the exit status of the program. */ 1455 debug("Exit status %d", exit_status); 1456 return exit_status; 1457 } 1458 1459 /*********/ 1460 1461 static Channel * 1462 client_request_forwarded_tcpip(struct ssh *ssh, const char *request_type, 1463 int rchan, u_int rwindow, u_int rmaxpack) 1464 { 1465 Channel *c = NULL; 1466 struct sshbuf *b = NULL; 1467 char *listen_address, *originator_address; 1468 u_int listen_port, originator_port; 1469 int r; 1470 1471 /* Get rest of the packet */ 1472 if ((r = sshpkt_get_cstring(ssh, &listen_address, NULL)) != 0 || 1473 (r = sshpkt_get_u32(ssh, &listen_port)) != 0 || 1474 (r = sshpkt_get_cstring(ssh, &originator_address, NULL)) != 0 || 1475 (r = sshpkt_get_u32(ssh, &originator_port)) != 0 || 1476 (r = sshpkt_get_end(ssh)) != 0) 1477 fatal_fr(r, "parse packet"); 1478 1479 debug_f("listen %s port %d, originator %s port %d", 1480 listen_address, listen_port, originator_address, originator_port); 1481 1482 if (listen_port > 0xffff) 1483 error_f("invalid listen port"); 1484 else if (originator_port > 0xffff) 1485 error_f("invalid originator port"); 1486 else { 1487 c = channel_connect_by_listen_address(ssh, 1488 listen_address, listen_port, "forwarded-tcpip", 1489 originator_address); 1490 } 1491 1492 if (c != NULL && c->type == SSH_CHANNEL_MUX_CLIENT) { 1493 if ((b = sshbuf_new()) == NULL) { 1494 error_f("alloc reply"); 1495 goto out; 1496 } 1497 /* reconstruct and send to muxclient */ 1498 if ((r = sshbuf_put_u8(b, 0)) != 0 || /* padlen */ 1499 (r = sshbuf_put_u8(b, SSH2_MSG_CHANNEL_OPEN)) != 0 || 1500 (r = sshbuf_put_cstring(b, request_type)) != 0 || 1501 (r = sshbuf_put_u32(b, rchan)) != 0 || 1502 (r = sshbuf_put_u32(b, rwindow)) != 0 || 1503 (r = sshbuf_put_u32(b, rmaxpack)) != 0 || 1504 (r = sshbuf_put_cstring(b, listen_address)) != 0 || 1505 (r = sshbuf_put_u32(b, listen_port)) != 0 || 1506 (r = sshbuf_put_cstring(b, originator_address)) != 0 || 1507 (r = sshbuf_put_u32(b, originator_port)) != 0 || 1508 (r = sshbuf_put_stringb(c->output, b)) != 0) { 1509 error_fr(r, "compose for muxclient"); 1510 goto out; 1511 } 1512 } 1513 1514 out: 1515 sshbuf_free(b); 1516 free(originator_address); 1517 free(listen_address); 1518 return c; 1519 } 1520 1521 static Channel * 1522 client_request_forwarded_streamlocal(struct ssh *ssh, 1523 const char *request_type, int rchan) 1524 { 1525 Channel *c = NULL; 1526 char *listen_path; 1527 int r; 1528 1529 /* Get the remote path. */ 1530 if ((r = sshpkt_get_cstring(ssh, &listen_path, NULL)) != 0 || 1531 (r = sshpkt_get_string(ssh, NULL, NULL)) != 0 || /* reserved */ 1532 (r = sshpkt_get_end(ssh)) != 0) 1533 fatal_fr(r, "parse packet"); 1534 1535 debug_f("request: %s", listen_path); 1536 1537 c = channel_connect_by_listen_path(ssh, listen_path, 1538 "forwarded-streamlocal@openssh.com", "forwarded-streamlocal"); 1539 free(listen_path); 1540 return c; 1541 } 1542 1543 static Channel * 1544 client_request_x11(struct ssh *ssh, const char *request_type, int rchan) 1545 { 1546 Channel *c = NULL; 1547 char *originator; 1548 u_int originator_port; 1549 int r, sock; 1550 1551 if (!options.forward_x11) { 1552 error("Warning: ssh server tried X11 forwarding."); 1553 error("Warning: this is probably a break-in attempt by a " 1554 "malicious server."); 1555 return NULL; 1556 } 1557 if (x11_refuse_time != 0 && (u_int)monotime() >= x11_refuse_time) { 1558 verbose("Rejected X11 connection after ForwardX11Timeout " 1559 "expired"); 1560 return NULL; 1561 } 1562 if ((r = sshpkt_get_cstring(ssh, &originator, NULL)) != 0 || 1563 (r = sshpkt_get_u32(ssh, &originator_port)) != 0 || 1564 (r = sshpkt_get_end(ssh)) != 0) 1565 fatal_fr(r, "parse packet"); 1566 /* XXX check permission */ 1567 /* XXX range check originator port? */ 1568 debug("client_request_x11: request from %s %u", originator, 1569 originator_port); 1570 free(originator); 1571 sock = x11_connect_display(ssh); 1572 if (sock < 0) 1573 return NULL; 1574 c = channel_new(ssh, "x11", 1575 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 1576 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1); 1577 c->force_drain = 1; 1578 return c; 1579 } 1580 1581 static Channel * 1582 client_request_agent(struct ssh *ssh, const char *request_type, int rchan) 1583 { 1584 Channel *c = NULL; 1585 int r, sock; 1586 1587 if (!options.forward_agent) { 1588 error("Warning: ssh server tried agent forwarding."); 1589 error("Warning: this is probably a break-in attempt by a " 1590 "malicious server."); 1591 return NULL; 1592 } 1593 if (forward_agent_sock_path == NULL) { 1594 r = ssh_get_authentication_socket(&sock); 1595 } else { 1596 r = ssh_get_authentication_socket_path(forward_agent_sock_path, &sock); 1597 } 1598 if (r != 0) { 1599 if (r != SSH_ERR_AGENT_NOT_PRESENT) 1600 debug_fr(r, "ssh_get_authentication_socket"); 1601 return NULL; 1602 } 1603 if ((r = ssh_agent_bind_hostkey(sock, ssh->kex->initial_hostkey, 1604 ssh->kex->session_id, ssh->kex->initial_sig, 1)) == 0) 1605 debug_f("bound agent to hostkey"); 1606 else 1607 debug2_fr(r, "ssh_agent_bind_hostkey"); 1608 1609 c = channel_new(ssh, "authentication agent connection", 1610 SSH_CHANNEL_OPEN, sock, sock, -1, 1611 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, 1612 "authentication agent connection", 1); 1613 c->force_drain = 1; 1614 return c; 1615 } 1616 1617 char * 1618 client_request_tun_fwd(struct ssh *ssh, int tun_mode, 1619 int local_tun, int remote_tun, channel_open_fn *cb, void *cbctx) 1620 { 1621 Channel *c; 1622 int r, fd; 1623 char *ifname = NULL; 1624 1625 if (tun_mode == SSH_TUNMODE_NO) 1626 return 0; 1627 1628 debug("Requesting tun unit %d in mode %d", local_tun, tun_mode); 1629 1630 /* Open local tunnel device */ 1631 if ((fd = tun_open(local_tun, tun_mode, &ifname)) == -1) { 1632 error("Tunnel device open failed."); 1633 return NULL; 1634 } 1635 debug("Tunnel forwarding using interface %s", ifname); 1636 1637 c = channel_new(ssh, "tun", SSH_CHANNEL_OPENING, fd, fd, -1, 1638 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); 1639 c->datagram = 1; 1640 1641 #if defined(SSH_TUN_FILTER) 1642 if (options.tun_open == SSH_TUNMODE_POINTOPOINT) 1643 channel_register_filter(ssh, c->self, sys_tun_infilter, 1644 sys_tun_outfilter, NULL, NULL); 1645 #endif 1646 1647 if (cb != NULL) 1648 channel_register_open_confirm(ssh, c->self, cb, cbctx); 1649 1650 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN)) != 0 || 1651 (r = sshpkt_put_cstring(ssh, "tun@openssh.com")) != 0 || 1652 (r = sshpkt_put_u32(ssh, c->self)) != 0 || 1653 (r = sshpkt_put_u32(ssh, c->local_window_max)) != 0 || 1654 (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 || 1655 (r = sshpkt_put_u32(ssh, tun_mode)) != 0 || 1656 (r = sshpkt_put_u32(ssh, remote_tun)) != 0 || 1657 (r = sshpkt_send(ssh)) != 0) 1658 sshpkt_fatal(ssh, r, "%s: send reply", __func__); 1659 1660 return ifname; 1661 } 1662 1663 /* XXXX move to generic input handler */ 1664 static int 1665 client_input_channel_open(int type, u_int32_t seq, struct ssh *ssh) 1666 { 1667 Channel *c = NULL; 1668 char *ctype = NULL; 1669 int r; 1670 u_int rchan; 1671 size_t len; 1672 u_int rmaxpack, rwindow; 1673 1674 if ((r = sshpkt_get_cstring(ssh, &ctype, &len)) != 0 || 1675 (r = sshpkt_get_u32(ssh, &rchan)) != 0 || 1676 (r = sshpkt_get_u32(ssh, &rwindow)) != 0 || 1677 (r = sshpkt_get_u32(ssh, &rmaxpack)) != 0) 1678 goto out; 1679 1680 debug("client_input_channel_open: ctype %s rchan %d win %d max %d", 1681 ctype, rchan, rwindow, rmaxpack); 1682 1683 if (strcmp(ctype, "forwarded-tcpip") == 0) { 1684 c = client_request_forwarded_tcpip(ssh, ctype, rchan, rwindow, 1685 rmaxpack); 1686 } else if (strcmp(ctype, "forwarded-streamlocal@openssh.com") == 0) { 1687 c = client_request_forwarded_streamlocal(ssh, ctype, rchan); 1688 } else if (strcmp(ctype, "x11") == 0) { 1689 c = client_request_x11(ssh, ctype, rchan); 1690 } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) { 1691 c = client_request_agent(ssh, ctype, rchan); 1692 } 1693 if (c != NULL && c->type == SSH_CHANNEL_MUX_CLIENT) { 1694 debug3("proxied to downstream: %s", ctype); 1695 } else if (c != NULL) { 1696 debug("confirm %s", ctype); 1697 c->remote_id = rchan; 1698 c->have_remote_id = 1; 1699 c->remote_window = rwindow; 1700 c->remote_maxpacket = rmaxpack; 1701 if (c->type != SSH_CHANNEL_CONNECTING) { 1702 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 || 1703 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 || 1704 (r = sshpkt_put_u32(ssh, c->self)) != 0 || 1705 (r = sshpkt_put_u32(ssh, c->local_window)) != 0 || 1706 (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 || 1707 (r = sshpkt_send(ssh)) != 0) 1708 sshpkt_fatal(ssh, r, "%s: send reply", __func__); 1709 } 1710 } else { 1711 debug("failure %s", ctype); 1712 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE)) != 0 || 1713 (r = sshpkt_put_u32(ssh, rchan)) != 0 || 1714 (r = sshpkt_put_u32(ssh, SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED)) != 0 || 1715 (r = sshpkt_put_cstring(ssh, "open failed")) != 0 || 1716 (r = sshpkt_put_cstring(ssh, "")) != 0 || 1717 (r = sshpkt_send(ssh)) != 0) 1718 sshpkt_fatal(ssh, r, "%s: send failure", __func__); 1719 } 1720 r = 0; 1721 out: 1722 free(ctype); 1723 return r; 1724 } 1725 1726 static int 1727 client_input_channel_req(int type, u_int32_t seq, struct ssh *ssh) 1728 { 1729 Channel *c = NULL; 1730 char *rtype = NULL; 1731 u_char reply; 1732 u_int id, exitval; 1733 int r, success = 0; 1734 1735 if ((r = sshpkt_get_u32(ssh, &id)) != 0) 1736 return r; 1737 if (id <= INT_MAX) 1738 c = channel_lookup(ssh, id); 1739 if (channel_proxy_upstream(c, type, seq, ssh)) 1740 return 0; 1741 if ((r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 || 1742 (r = sshpkt_get_u8(ssh, &reply)) != 0) 1743 goto out; 1744 1745 debug("client_input_channel_req: channel %u rtype %s reply %d", 1746 id, rtype, reply); 1747 1748 if (c == NULL) { 1749 error("client_input_channel_req: channel %d: " 1750 "unknown channel", id); 1751 } else if (strcmp(rtype, "eow@openssh.com") == 0) { 1752 if ((r = sshpkt_get_end(ssh)) != 0) 1753 goto out; 1754 chan_rcvd_eow(ssh, c); 1755 } else if (strcmp(rtype, "exit-status") == 0) { 1756 if ((r = sshpkt_get_u32(ssh, &exitval)) != 0) 1757 goto out; 1758 if (c->ctl_chan != -1) { 1759 mux_exit_message(ssh, c, exitval); 1760 success = 1; 1761 } else if ((int)id == session_ident) { 1762 /* Record exit value of local session */ 1763 success = 1; 1764 exit_status = exitval; 1765 } else { 1766 /* Probably for a mux channel that has already closed */ 1767 debug_f("no sink for exit-status on channel %d", 1768 id); 1769 } 1770 if ((r = sshpkt_get_end(ssh)) != 0) 1771 goto out; 1772 } 1773 if (reply && c != NULL && !(c->flags & CHAN_CLOSE_SENT)) { 1774 if (!c->have_remote_id) 1775 fatal_f("channel %d: no remote_id", c->self); 1776 if ((r = sshpkt_start(ssh, success ? 1777 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE)) != 0 || 1778 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 || 1779 (r = sshpkt_send(ssh)) != 0) 1780 sshpkt_fatal(ssh, r, "%s: send failure", __func__); 1781 } 1782 r = 0; 1783 out: 1784 free(rtype); 1785 return r; 1786 } 1787 1788 struct hostkeys_update_ctx { 1789 /* The hostname and (optionally) IP address string for the server */ 1790 char *host_str, *ip_str; 1791 1792 /* 1793 * Keys received from the server and a flag for each indicating 1794 * whether they already exist in known_hosts. 1795 * keys_match is filled in by hostkeys_find() and later (for new 1796 * keys) by client_global_hostkeys_private_confirm(). 1797 */ 1798 struct sshkey **keys; 1799 u_int *keys_match; /* mask of HKF_MATCH_* from hostfile.h */ 1800 int *keys_verified; /* flag for new keys verified by server */ 1801 size_t nkeys, nnew, nincomplete; /* total, new keys, incomplete match */ 1802 1803 /* 1804 * Keys that are in known_hosts, but were not present in the update 1805 * from the server (i.e. scheduled to be deleted). 1806 * Filled in by hostkeys_find(). 1807 */ 1808 struct sshkey **old_keys; 1809 size_t nold; 1810 1811 /* Various special cases. */ 1812 int complex_hostspec; /* wildcard or manual pattern-list host name */ 1813 int ca_available; /* saw CA key for this host */ 1814 int old_key_seen; /* saw old key with other name/addr */ 1815 int other_name_seen; /* saw key with other name/addr */ 1816 }; 1817 1818 static void 1819 hostkeys_update_ctx_free(struct hostkeys_update_ctx *ctx) 1820 { 1821 size_t i; 1822 1823 if (ctx == NULL) 1824 return; 1825 for (i = 0; i < ctx->nkeys; i++) 1826 sshkey_free(ctx->keys[i]); 1827 free(ctx->keys); 1828 free(ctx->keys_match); 1829 free(ctx->keys_verified); 1830 for (i = 0; i < ctx->nold; i++) 1831 sshkey_free(ctx->old_keys[i]); 1832 free(ctx->old_keys); 1833 free(ctx->host_str); 1834 free(ctx->ip_str); 1835 free(ctx); 1836 } 1837 1838 /* 1839 * Returns non-zero if a known_hosts hostname list is not of a form that 1840 * can be handled by UpdateHostkeys. These include wildcard hostnames and 1841 * hostnames lists that do not follow the form host[,ip]. 1842 */ 1843 static int 1844 hostspec_is_complex(const char *hosts) 1845 { 1846 char *cp; 1847 1848 /* wildcard */ 1849 if (strchr(hosts, '*') != NULL || strchr(hosts, '?') != NULL) 1850 return 1; 1851 /* single host/ip = ok */ 1852 if ((cp = strchr(hosts, ',')) == NULL) 1853 return 0; 1854 /* more than two entries on the line */ 1855 if (strchr(cp + 1, ',') != NULL) 1856 return 1; 1857 /* XXX maybe parse cp+1 and ensure it is an IP? */ 1858 return 0; 1859 } 1860 1861 /* callback to search for ctx->keys in known_hosts */ 1862 static int 1863 hostkeys_find(struct hostkey_foreach_line *l, void *_ctx) 1864 { 1865 struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx; 1866 size_t i; 1867 struct sshkey **tmp; 1868 1869 if (l->key == NULL) 1870 return 0; 1871 if (l->status != HKF_STATUS_MATCHED) { 1872 /* Record if one of the keys appears on a non-matching line */ 1873 for (i = 0; i < ctx->nkeys; i++) { 1874 if (sshkey_equal(l->key, ctx->keys[i])) { 1875 ctx->other_name_seen = 1; 1876 debug3_f("found %s key under different " 1877 "name/addr at %s:%ld", 1878 sshkey_ssh_name(ctx->keys[i]), 1879 l->path, l->linenum); 1880 return 0; 1881 } 1882 } 1883 return 0; 1884 } 1885 /* Don't proceed if revocation or CA markers are present */ 1886 /* XXX relax this */ 1887 if (l->marker != MRK_NONE) { 1888 debug3_f("hostkeys file %s:%ld has CA/revocation marker", 1889 l->path, l->linenum); 1890 ctx->complex_hostspec = 1; 1891 return 0; 1892 } 1893 1894 /* If CheckHostIP is enabled, then check for mismatched hostname/addr */ 1895 if (ctx->ip_str != NULL && strchr(l->hosts, ',') != NULL) { 1896 if ((l->match & HKF_MATCH_HOST) == 0) { 1897 /* Record if address matched a different hostname. */ 1898 ctx->other_name_seen = 1; 1899 debug3_f("found address %s against different hostname " 1900 "at %s:%ld", ctx->ip_str, l->path, l->linenum); 1901 return 0; 1902 } else if ((l->match & HKF_MATCH_IP) == 0) { 1903 /* Record if hostname matched a different address. */ 1904 ctx->other_name_seen = 1; 1905 debug3_f("found hostname %s against different address " 1906 "at %s:%ld", ctx->host_str, l->path, l->linenum); 1907 } 1908 } 1909 1910 /* 1911 * UpdateHostkeys is skipped for wildcard host names and hostnames 1912 * that contain more than two entries (ssh never writes these). 1913 */ 1914 if (hostspec_is_complex(l->hosts)) { 1915 debug3_f("hostkeys file %s:%ld complex host specification", 1916 l->path, l->linenum); 1917 ctx->complex_hostspec = 1; 1918 return 0; 1919 } 1920 1921 /* Mark off keys we've already seen for this host */ 1922 for (i = 0; i < ctx->nkeys; i++) { 1923 if (!sshkey_equal(l->key, ctx->keys[i])) 1924 continue; 1925 debug3_f("found %s key at %s:%ld", 1926 sshkey_ssh_name(ctx->keys[i]), l->path, l->linenum); 1927 ctx->keys_match[i] |= l->match; 1928 return 0; 1929 } 1930 /* This line contained a key that not offered by the server */ 1931 debug3_f("deprecated %s key at %s:%ld", sshkey_ssh_name(l->key), 1932 l->path, l->linenum); 1933 if ((tmp = recallocarray(ctx->old_keys, ctx->nold, ctx->nold + 1, 1934 sizeof(*ctx->old_keys))) == NULL) 1935 fatal_f("recallocarray failed nold = %zu", ctx->nold); 1936 ctx->old_keys = tmp; 1937 ctx->old_keys[ctx->nold++] = l->key; 1938 l->key = NULL; 1939 1940 return 0; 1941 } 1942 1943 /* callback to search for ctx->old_keys in known_hosts under other names */ 1944 static int 1945 hostkeys_check_old(struct hostkey_foreach_line *l, void *_ctx) 1946 { 1947 struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx; 1948 size_t i; 1949 int hashed; 1950 1951 /* only care about lines that *don't* match the active host spec */ 1952 if (l->status == HKF_STATUS_MATCHED || l->key == NULL) 1953 return 0; 1954 1955 hashed = l->match & (HKF_MATCH_HOST_HASHED|HKF_MATCH_IP_HASHED); 1956 for (i = 0; i < ctx->nold; i++) { 1957 if (!sshkey_equal(l->key, ctx->old_keys[i])) 1958 continue; 1959 debug3_f("found deprecated %s key at %s:%ld as %s", 1960 sshkey_ssh_name(ctx->old_keys[i]), l->path, l->linenum, 1961 hashed ? "[HASHED]" : l->hosts); 1962 ctx->old_key_seen = 1; 1963 break; 1964 } 1965 return 0; 1966 } 1967 1968 /* 1969 * Check known_hosts files for deprecated keys under other names. Returns 0 1970 * on success or -1 on failure. Updates ctx->old_key_seen if deprecated keys 1971 * exist under names other than the active hostname/IP. 1972 */ 1973 static int 1974 check_old_keys_othernames(struct hostkeys_update_ctx *ctx) 1975 { 1976 size_t i; 1977 int r; 1978 1979 debug2_f("checking for %zu deprecated keys", ctx->nold); 1980 for (i = 0; i < options.num_user_hostfiles; i++) { 1981 debug3_f("searching %s for %s / %s", 1982 options.user_hostfiles[i], ctx->host_str, 1983 ctx->ip_str ? ctx->ip_str : "(none)"); 1984 if ((r = hostkeys_foreach(options.user_hostfiles[i], 1985 hostkeys_check_old, ctx, ctx->host_str, ctx->ip_str, 1986 HKF_WANT_PARSE_KEY, 0)) != 0) { 1987 if (r == SSH_ERR_SYSTEM_ERROR && errno == ENOENT) { 1988 debug_f("hostkeys file %s does not exist", 1989 options.user_hostfiles[i]); 1990 continue; 1991 } 1992 error_fr(r, "hostkeys_foreach failed for %s", 1993 options.user_hostfiles[i]); 1994 return -1; 1995 } 1996 } 1997 return 0; 1998 } 1999 2000 static void 2001 hostkey_change_preamble(LogLevel loglevel) 2002 { 2003 do_log2(loglevel, "The server has updated its host keys."); 2004 do_log2(loglevel, "These changes were verified by the server's " 2005 "existing trusted key."); 2006 } 2007 2008 static void 2009 update_known_hosts(struct hostkeys_update_ctx *ctx) 2010 { 2011 int r, was_raw = 0, first = 1; 2012 int asking = options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK; 2013 LogLevel loglevel = asking ? SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_VERBOSE; 2014 char *fp, *response; 2015 size_t i; 2016 struct stat sb; 2017 2018 for (i = 0; i < ctx->nkeys; i++) { 2019 if (!ctx->keys_verified[i]) 2020 continue; 2021 if ((fp = sshkey_fingerprint(ctx->keys[i], 2022 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) 2023 fatal_f("sshkey_fingerprint failed"); 2024 if (first && asking) 2025 hostkey_change_preamble(loglevel); 2026 do_log2(loglevel, "Learned new hostkey: %s %s", 2027 sshkey_type(ctx->keys[i]), fp); 2028 first = 0; 2029 free(fp); 2030 } 2031 for (i = 0; i < ctx->nold; i++) { 2032 if ((fp = sshkey_fingerprint(ctx->old_keys[i], 2033 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) 2034 fatal_f("sshkey_fingerprint failed"); 2035 if (first && asking) 2036 hostkey_change_preamble(loglevel); 2037 do_log2(loglevel, "Deprecating obsolete hostkey: %s %s", 2038 sshkey_type(ctx->old_keys[i]), fp); 2039 first = 0; 2040 free(fp); 2041 } 2042 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { 2043 if (get_saved_tio() != NULL) { 2044 leave_raw_mode(1); 2045 was_raw = 1; 2046 } 2047 response = NULL; 2048 for (i = 0; !quit_pending && i < 3; i++) { 2049 free(response); 2050 response = read_passphrase("Accept updated hostkeys? " 2051 "(yes/no): ", RP_ECHO); 2052 if (strcasecmp(response, "yes") == 0) 2053 break; 2054 else if (quit_pending || response == NULL || 2055 strcasecmp(response, "no") == 0) { 2056 options.update_hostkeys = 0; 2057 break; 2058 } else { 2059 do_log2(loglevel, "Please enter " 2060 "\"yes\" or \"no\""); 2061 } 2062 } 2063 if (quit_pending || i >= 3 || response == NULL) 2064 options.update_hostkeys = 0; 2065 free(response); 2066 if (was_raw) 2067 enter_raw_mode(1); 2068 } 2069 if (options.update_hostkeys == 0) 2070 return; 2071 /* 2072 * Now that all the keys are verified, we can go ahead and replace 2073 * them in known_hosts (assuming SSH_UPDATE_HOSTKEYS_ASK didn't 2074 * cancel the operation). 2075 */ 2076 for (i = 0; i < options.num_user_hostfiles; i++) { 2077 /* 2078 * NB. keys are only added to hostfiles[0], for the rest we 2079 * just delete the hostname entries. 2080 */ 2081 if (stat(options.user_hostfiles[i], &sb) != 0) { 2082 if (errno == ENOENT) { 2083 debug_f("known hosts file %s does not " 2084 "exist", options.user_hostfiles[i]); 2085 } else { 2086 error_f("known hosts file %s " 2087 "inaccessible: %s", 2088 options.user_hostfiles[i], strerror(errno)); 2089 } 2090 continue; 2091 } 2092 if ((r = hostfile_replace_entries(options.user_hostfiles[i], 2093 ctx->host_str, ctx->ip_str, 2094 i == 0 ? ctx->keys : NULL, i == 0 ? ctx->nkeys : 0, 2095 options.hash_known_hosts, 0, 2096 options.fingerprint_hash)) != 0) { 2097 error_fr(r, "hostfile_replace_entries failed for %s", 2098 options.user_hostfiles[i]); 2099 } 2100 } 2101 } 2102 2103 static void 2104 client_global_hostkeys_private_confirm(struct ssh *ssh, int type, 2105 u_int32_t seq, void *_ctx) 2106 { 2107 struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx; 2108 size_t i, ndone; 2109 struct sshbuf *signdata; 2110 int r, plaintype; 2111 const u_char *sig; 2112 const char *rsa_kexalg = NULL; 2113 char *alg = NULL; 2114 size_t siglen; 2115 2116 if (ctx->nnew == 0) 2117 fatal_f("ctx->nnew == 0"); /* sanity */ 2118 if (type != SSH2_MSG_REQUEST_SUCCESS) { 2119 error("Server failed to confirm ownership of " 2120 "private host keys"); 2121 hostkeys_update_ctx_free(ctx); 2122 return; 2123 } 2124 if (sshkey_type_plain(sshkey_type_from_name( 2125 ssh->kex->hostkey_alg)) == KEY_RSA) 2126 rsa_kexalg = ssh->kex->hostkey_alg; 2127 if ((signdata = sshbuf_new()) == NULL) 2128 fatal_f("sshbuf_new failed"); 2129 /* 2130 * Expect a signature for each of the ctx->nnew private keys we 2131 * haven't seen before. They will be in the same order as the 2132 * ctx->keys where the corresponding ctx->keys_match[i] == 0. 2133 */ 2134 for (ndone = i = 0; i < ctx->nkeys; i++) { 2135 if (ctx->keys_match[i]) 2136 continue; 2137 plaintype = sshkey_type_plain(ctx->keys[i]->type); 2138 /* Prepare data to be signed: session ID, unique string, key */ 2139 sshbuf_reset(signdata); 2140 if ( (r = sshbuf_put_cstring(signdata, 2141 "hostkeys-prove-00@openssh.com")) != 0 || 2142 (r = sshbuf_put_stringb(signdata, 2143 ssh->kex->session_id)) != 0 || 2144 (r = sshkey_puts(ctx->keys[i], signdata)) != 0) 2145 fatal_fr(r, "compose signdata"); 2146 /* Extract and verify signature */ 2147 if ((r = sshpkt_get_string_direct(ssh, &sig, &siglen)) != 0) { 2148 error_fr(r, "parse sig"); 2149 goto out; 2150 } 2151 if ((r = sshkey_get_sigtype(sig, siglen, &alg)) != 0) { 2152 error_fr(r, "server gave unintelligible signature " 2153 "for %s key %zu", sshkey_type(ctx->keys[i]), i); 2154 goto out; 2155 } 2156 /* 2157 * Special case for RSA keys: if a RSA hostkey was negotiated, 2158 * then use its signature type for verification of RSA hostkey 2159 * proofs. Otherwise, accept only RSA-SHA256/512 signatures. 2160 */ 2161 if (plaintype == KEY_RSA && rsa_kexalg == NULL && 2162 match_pattern_list(alg, HOSTKEY_PROOF_RSA_ALGS, 0) != 1) { 2163 debug_f("server used untrusted RSA signature algorithm " 2164 "%s for key %zu, disregarding", alg, i); 2165 free(alg); 2166 /* zap the key from the list */ 2167 sshkey_free(ctx->keys[i]); 2168 ctx->keys[i] = NULL; 2169 ndone++; 2170 continue; 2171 } 2172 debug3_f("verify %s key %zu using sigalg %s", 2173 sshkey_type(ctx->keys[i]), i, alg); 2174 free(alg); 2175 if ((r = sshkey_verify(ctx->keys[i], sig, siglen, 2176 sshbuf_ptr(signdata), sshbuf_len(signdata), 2177 plaintype == KEY_RSA ? rsa_kexalg : NULL, 0, NULL)) != 0) { 2178 error_fr(r, "server gave bad signature for %s key %zu", 2179 sshkey_type(ctx->keys[i]), i); 2180 goto out; 2181 } 2182 /* Key is good. Mark it as 'seen' */ 2183 ctx->keys_verified[i] = 1; 2184 ndone++; 2185 } 2186 /* Shouldn't happen */ 2187 if (ndone != ctx->nnew) 2188 fatal_f("ndone != ctx->nnew (%zu / %zu)", ndone, ctx->nnew); 2189 if ((r = sshpkt_get_end(ssh)) != 0) { 2190 error_f("protocol error"); 2191 goto out; 2192 } 2193 2194 /* Make the edits to known_hosts */ 2195 update_known_hosts(ctx); 2196 out: 2197 hostkeys_update_ctx_free(ctx); 2198 } 2199 2200 /* 2201 * Returns non-zero if the key is accepted by HostkeyAlgorithms. 2202 * Made slightly less trivial by the multiple RSA signature algorithm names. 2203 */ 2204 static int 2205 key_accepted_by_hostkeyalgs(const struct sshkey *key) 2206 { 2207 const char *ktype = sshkey_ssh_name(key); 2208 const char *hostkeyalgs = options.hostkeyalgorithms; 2209 2210 if (key == NULL || key->type == KEY_UNSPEC) 2211 return 0; 2212 if (key->type == KEY_RSA && 2213 (match_pattern_list("rsa-sha2-256", hostkeyalgs, 0) == 1 || 2214 match_pattern_list("rsa-sha2-512", hostkeyalgs, 0) == 1)) 2215 return 1; 2216 return match_pattern_list(ktype, hostkeyalgs, 0) == 1; 2217 } 2218 2219 /* 2220 * Handle hostkeys-00@openssh.com global request to inform the client of all 2221 * the server's hostkeys. The keys are checked against the user's 2222 * HostkeyAlgorithms preference before they are accepted. 2223 */ 2224 static int 2225 client_input_hostkeys(struct ssh *ssh) 2226 { 2227 const u_char *blob = NULL; 2228 size_t i, len = 0; 2229 struct sshbuf *buf = NULL; 2230 struct sshkey *key = NULL, **tmp; 2231 int r; 2232 char *fp; 2233 static int hostkeys_seen = 0; /* XXX use struct ssh */ 2234 extern struct sockaddr_storage hostaddr; /* XXX from ssh.c */ 2235 struct hostkeys_update_ctx *ctx = NULL; 2236 u_int want; 2237 2238 if (hostkeys_seen) 2239 fatal_f("server already sent hostkeys"); 2240 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK && 2241 options.batch_mode) 2242 return 1; /* won't ask in batchmode, so don't even try */ 2243 if (!options.update_hostkeys || options.num_user_hostfiles <= 0) 2244 return 1; 2245 2246 ctx = xcalloc(1, sizeof(*ctx)); 2247 while (ssh_packet_remaining(ssh) > 0) { 2248 sshkey_free(key); 2249 key = NULL; 2250 if ((r = sshpkt_get_string_direct(ssh, &blob, &len)) != 0) { 2251 error_fr(r, "parse key"); 2252 goto out; 2253 } 2254 if ((r = sshkey_from_blob(blob, len, &key)) != 0) { 2255 do_log2_fr(r, r == SSH_ERR_KEY_TYPE_UNKNOWN ? 2256 SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_ERROR, 2257 "convert key"); 2258 continue; 2259 } 2260 fp = sshkey_fingerprint(key, options.fingerprint_hash, 2261 SSH_FP_DEFAULT); 2262 debug3_f("received %s key %s", sshkey_type(key), fp); 2263 free(fp); 2264 2265 if (!key_accepted_by_hostkeyalgs(key)) { 2266 debug3_f("%s key not permitted by " 2267 "HostkeyAlgorithms", sshkey_ssh_name(key)); 2268 continue; 2269 } 2270 /* Skip certs */ 2271 if (sshkey_is_cert(key)) { 2272 debug3_f("%s key is a certificate; skipping", 2273 sshkey_ssh_name(key)); 2274 continue; 2275 } 2276 /* Ensure keys are unique */ 2277 for (i = 0; i < ctx->nkeys; i++) { 2278 if (sshkey_equal(key, ctx->keys[i])) { 2279 error_f("received duplicated %s host key", 2280 sshkey_ssh_name(key)); 2281 goto out; 2282 } 2283 } 2284 /* Key is good, record it */ 2285 if ((tmp = recallocarray(ctx->keys, ctx->nkeys, ctx->nkeys + 1, 2286 sizeof(*ctx->keys))) == NULL) 2287 fatal_f("recallocarray failed nkeys = %zu", 2288 ctx->nkeys); 2289 ctx->keys = tmp; 2290 ctx->keys[ctx->nkeys++] = key; 2291 key = NULL; 2292 } 2293 2294 if (ctx->nkeys == 0) { 2295 debug_f("server sent no hostkeys"); 2296 goto out; 2297 } 2298 2299 if ((ctx->keys_match = calloc(ctx->nkeys, 2300 sizeof(*ctx->keys_match))) == NULL || 2301 (ctx->keys_verified = calloc(ctx->nkeys, 2302 sizeof(*ctx->keys_verified))) == NULL) 2303 fatal_f("calloc failed"); 2304 2305 get_hostfile_hostname_ipaddr(host, 2306 options.check_host_ip ? (struct sockaddr *)&hostaddr : NULL, 2307 options.port, &ctx->host_str, 2308 options.check_host_ip ? &ctx->ip_str : NULL); 2309 2310 /* Find which keys we already know about. */ 2311 for (i = 0; i < options.num_user_hostfiles; i++) { 2312 debug_f("searching %s for %s / %s", 2313 options.user_hostfiles[i], ctx->host_str, 2314 ctx->ip_str ? ctx->ip_str : "(none)"); 2315 if ((r = hostkeys_foreach(options.user_hostfiles[i], 2316 hostkeys_find, ctx, ctx->host_str, ctx->ip_str, 2317 HKF_WANT_PARSE_KEY, 0)) != 0) { 2318 if (r == SSH_ERR_SYSTEM_ERROR && errno == ENOENT) { 2319 debug_f("hostkeys file %s does not exist", 2320 options.user_hostfiles[i]); 2321 continue; 2322 } 2323 error_fr(r, "hostkeys_foreach failed for %s", 2324 options.user_hostfiles[i]); 2325 goto out; 2326 } 2327 } 2328 2329 /* Figure out if we have any new keys to add */ 2330 ctx->nnew = ctx->nincomplete = 0; 2331 want = HKF_MATCH_HOST | ( options.check_host_ip ? HKF_MATCH_IP : 0); 2332 for (i = 0; i < ctx->nkeys; i++) { 2333 if (ctx->keys_match[i] == 0) 2334 ctx->nnew++; 2335 if ((ctx->keys_match[i] & want) != want) 2336 ctx->nincomplete++; 2337 } 2338 2339 debug3_f("%zu server keys: %zu new, %zu retained, " 2340 "%zu incomplete match. %zu to remove", ctx->nkeys, ctx->nnew, 2341 ctx->nkeys - ctx->nnew - ctx->nincomplete, 2342 ctx->nincomplete, ctx->nold); 2343 2344 if (ctx->nnew == 0 && ctx->nold == 0) { 2345 debug_f("no new or deprecated keys from server"); 2346 goto out; 2347 } 2348 2349 /* Various reasons why we cannot proceed with the update */ 2350 if (ctx->complex_hostspec) { 2351 debug_f("CA/revocation marker, manual host list or wildcard " 2352 "host pattern found, skipping UserKnownHostsFile update"); 2353 goto out; 2354 } 2355 if (ctx->other_name_seen) { 2356 debug_f("host key found matching a different name/address, " 2357 "skipping UserKnownHostsFile update"); 2358 goto out; 2359 } 2360 /* 2361 * If removing keys, check whether they appear under different 2362 * names/addresses and refuse to proceed if they do. This avoids 2363 * cases such as hosts with multiple names becoming inconsistent 2364 * with regards to CheckHostIP entries. 2365 * XXX UpdateHostkeys=force to override this (and other) checks? 2366 */ 2367 if (ctx->nold != 0) { 2368 if (check_old_keys_othernames(ctx) != 0) 2369 goto out; /* error already logged */ 2370 if (ctx->old_key_seen) { 2371 debug_f("key(s) for %s%s%s exist under other names; " 2372 "skipping UserKnownHostsFile update", 2373 ctx->host_str, ctx->ip_str == NULL ? "" : ",", 2374 ctx->ip_str == NULL ? "" : ctx->ip_str); 2375 goto out; 2376 } 2377 } 2378 2379 if (ctx->nnew == 0) { 2380 /* 2381 * We have some keys to remove or fix matching for. 2382 * We can proceed to do this without requiring a fresh proof 2383 * from the server. 2384 */ 2385 update_known_hosts(ctx); 2386 goto out; 2387 } 2388 /* 2389 * We have received previously-unseen keys from the server. 2390 * Ask the server to confirm ownership of the private halves. 2391 */ 2392 debug3_f("asking server to prove ownership for %zu keys", ctx->nnew); 2393 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || 2394 (r = sshpkt_put_cstring(ssh, 2395 "hostkeys-prove-00@openssh.com")) != 0 || 2396 (r = sshpkt_put_u8(ssh, 1)) != 0) /* bool: want reply */ 2397 fatal_fr(r, "prepare hostkeys-prove"); 2398 if ((buf = sshbuf_new()) == NULL) 2399 fatal_f("sshbuf_new"); 2400 for (i = 0; i < ctx->nkeys; i++) { 2401 if (ctx->keys_match[i]) 2402 continue; 2403 sshbuf_reset(buf); 2404 if ((r = sshkey_putb(ctx->keys[i], buf)) != 0 || 2405 (r = sshpkt_put_stringb(ssh, buf)) != 0) 2406 fatal_fr(r, "assemble hostkeys-prove"); 2407 } 2408 if ((r = sshpkt_send(ssh)) != 0) 2409 fatal_fr(r, "send hostkeys-prove"); 2410 client_register_global_confirm( 2411 client_global_hostkeys_private_confirm, ctx); 2412 ctx = NULL; /* will be freed in callback */ 2413 2414 /* Success */ 2415 out: 2416 hostkeys_update_ctx_free(ctx); 2417 sshkey_free(key); 2418 sshbuf_free(buf); 2419 /* 2420 * NB. Return success for all cases. The server doesn't need to know 2421 * what the client does with its hosts file. 2422 */ 2423 return 1; 2424 } 2425 2426 static int 2427 client_input_global_request(int type, u_int32_t seq, struct ssh *ssh) 2428 { 2429 char *rtype; 2430 u_char want_reply; 2431 int r, success = 0; 2432 2433 if ((r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 || 2434 (r = sshpkt_get_u8(ssh, &want_reply)) != 0) 2435 goto out; 2436 debug("client_input_global_request: rtype %s want_reply %d", 2437 rtype, want_reply); 2438 if (strcmp(rtype, "hostkeys-00@openssh.com") == 0) 2439 success = client_input_hostkeys(ssh); 2440 if (want_reply) { 2441 if ((r = sshpkt_start(ssh, success ? SSH2_MSG_REQUEST_SUCCESS : 2442 SSH2_MSG_REQUEST_FAILURE)) != 0 || 2443 (r = sshpkt_send(ssh)) != 0 || 2444 (r = ssh_packet_write_wait(ssh)) != 0) 2445 goto out; 2446 } 2447 r = 0; 2448 out: 2449 free(rtype); 2450 return r; 2451 } 2452 2453 static void 2454 client_send_env(struct ssh *ssh, int id, const char *name, const char *val) 2455 { 2456 int r; 2457 2458 debug("channel %d: setting env %s = \"%s\"", id, name, val); 2459 channel_request_start(ssh, id, "env", 0); 2460 if ((r = sshpkt_put_cstring(ssh, name)) != 0 || 2461 (r = sshpkt_put_cstring(ssh, val)) != 0 || 2462 (r = sshpkt_send(ssh)) != 0) 2463 fatal_fr(r, "send setenv"); 2464 } 2465 2466 void 2467 client_session2_setup(struct ssh *ssh, int id, int want_tty, int want_subsystem, 2468 const char *term, struct termios *tiop, int in_fd, struct sshbuf *cmd, 2469 char **env) 2470 { 2471 int i, j, matched, len, r; 2472 char *name, *val; 2473 Channel *c = NULL; 2474 2475 debug2_f("id %d", id); 2476 2477 if ((c = channel_lookup(ssh, id)) == NULL) 2478 fatal_f("channel %d: unknown channel", id); 2479 2480 ssh_packet_set_interactive(ssh, want_tty, 2481 options.ip_qos_interactive, options.ip_qos_bulk); 2482 2483 if (want_tty) { 2484 struct winsize ws; 2485 2486 /* Store window size in the packet. */ 2487 if (ioctl(in_fd, TIOCGWINSZ, &ws) == -1) 2488 memset(&ws, 0, sizeof(ws)); 2489 2490 channel_request_start(ssh, id, "pty-req", 1); 2491 client_expect_confirm(ssh, id, "PTY allocation", CONFIRM_TTY); 2492 if ((r = sshpkt_put_cstring(ssh, term != NULL ? term : "")) 2493 != 0 || 2494 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_col)) != 0 || 2495 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_row)) != 0 || 2496 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_xpixel)) != 0 || 2497 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_ypixel)) != 0) 2498 fatal_fr(r, "build pty-req"); 2499 if (tiop == NULL) 2500 tiop = get_saved_tio(); 2501 ssh_tty_make_modes(ssh, -1, tiop); 2502 if ((r = sshpkt_send(ssh)) != 0) 2503 fatal_fr(r, "send pty-req"); 2504 /* XXX wait for reply */ 2505 c->client_tty = 1; 2506 } 2507 2508 /* Transfer any environment variables from client to server */ 2509 if (options.num_send_env != 0 && env != NULL) { 2510 debug("Sending environment."); 2511 for (i = 0; env[i] != NULL; i++) { 2512 /* Split */ 2513 name = xstrdup(env[i]); 2514 if ((val = strchr(name, '=')) == NULL) { 2515 free(name); 2516 continue; 2517 } 2518 *val++ = '\0'; 2519 2520 matched = 0; 2521 for (j = 0; j < options.num_send_env; j++) { 2522 if (match_pattern(name, options.send_env[j])) { 2523 matched = 1; 2524 break; 2525 } 2526 } 2527 if (!matched) { 2528 debug3("Ignored env %s", name); 2529 free(name); 2530 continue; 2531 } 2532 client_send_env(ssh, id, name, val); 2533 free(name); 2534 } 2535 } 2536 for (i = 0; i < options.num_setenv; i++) { 2537 /* Split */ 2538 name = xstrdup(options.setenv[i]); 2539 if ((val = strchr(name, '=')) == NULL) { 2540 free(name); 2541 continue; 2542 } 2543 *val++ = '\0'; 2544 client_send_env(ssh, id, name, val); 2545 free(name); 2546 } 2547 2548 len = sshbuf_len(cmd); 2549 if (len > 0) { 2550 if (len > 900) 2551 len = 900; 2552 if (want_subsystem) { 2553 debug("Sending subsystem: %.*s", 2554 len, (const u_char*)sshbuf_ptr(cmd)); 2555 channel_request_start(ssh, id, "subsystem", 1); 2556 client_expect_confirm(ssh, id, "subsystem", 2557 CONFIRM_CLOSE); 2558 } else { 2559 debug("Sending command: %.*s", 2560 len, (const u_char*)sshbuf_ptr(cmd)); 2561 channel_request_start(ssh, id, "exec", 1); 2562 client_expect_confirm(ssh, id, "exec", CONFIRM_CLOSE); 2563 } 2564 if ((r = sshpkt_put_stringb(ssh, cmd)) != 0 || 2565 (r = sshpkt_send(ssh)) != 0) 2566 fatal_fr(r, "send command"); 2567 } else { 2568 channel_request_start(ssh, id, "shell", 1); 2569 client_expect_confirm(ssh, id, "shell", CONFIRM_CLOSE); 2570 if ((r = sshpkt_send(ssh)) != 0) 2571 fatal_fr(r, "send shell"); 2572 } 2573 } 2574 2575 static void 2576 client_init_dispatch(struct ssh *ssh) 2577 { 2578 ssh_dispatch_init(ssh, &dispatch_protocol_error); 2579 2580 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); 2581 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_DATA, &channel_input_data); 2582 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); 2583 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); 2584 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open); 2585 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 2586 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 2587 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req); 2588 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); 2589 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm); 2590 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm); 2591 ssh_dispatch_set(ssh, SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request); 2592 2593 /* rekeying */ 2594 ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, &kex_input_kexinit); 2595 2596 /* global request reply messages */ 2597 ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply); 2598 ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply); 2599 } 2600 2601 void 2602 client_stop_mux(void) 2603 { 2604 if (options.control_path != NULL && muxserver_sock != -1) 2605 unlink(options.control_path); 2606 /* 2607 * If we are in persist mode, or don't have a shell, signal that we 2608 * should close when all active channels are closed. 2609 */ 2610 if (options.control_persist || options.session_type == SESSION_TYPE_NONE) { 2611 session_closed = 1; 2612 setproctitle("[stopped mux]"); 2613 } 2614 } 2615 2616 /* client specific fatal cleanup */ 2617 void 2618 cleanup_exit(int i) 2619 { 2620 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 2621 if (options.control_path != NULL && muxserver_sock != -1) 2622 unlink(options.control_path); 2623 ssh_kill_proxy_command(); 2624 _exit(i); 2625 } 2626