1 /* $OpenBSD: clientloop.c,v 1.361 2021/05/03 00:16:45 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 63 #include <sys/types.h> 64 #include <sys/ioctl.h> 65 #include <sys/stat.h> 66 #include <sys/socket.h> 67 #include <sys/time.h> 68 #include <sys/queue.h> 69 70 #include <ctype.h> 71 #include <errno.h> 72 #include <paths.h> 73 #include <signal.h> 74 #include <stdio.h> 75 #include <stdlib.h> 76 #include <string.h> 77 #include <stdarg.h> 78 #include <termios.h> 79 #include <pwd.h> 80 #include <unistd.h> 81 #include <limits.h> 82 83 #include "xmalloc.h" 84 #include "ssh.h" 85 #include "ssh2.h" 86 #include "packet.h" 87 #include "sshbuf.h" 88 #include "compat.h" 89 #include "channels.h" 90 #include "dispatch.h" 91 #include "sshkey.h" 92 #include "cipher.h" 93 #include "kex.h" 94 #include "myproposal.h" 95 #include "log.h" 96 #include "misc.h" 97 #include "readconf.h" 98 #include "clientloop.h" 99 #include "sshconnect.h" 100 #include "authfd.h" 101 #include "atomicio.h" 102 #include "sshpty.h" 103 #include "match.h" 104 #include "msg.h" 105 #include "ssherr.h" 106 #include "hostfile.h" 107 108 /* import options */ 109 extern Options options; 110 111 /* Flag indicating that stdin should be redirected from /dev/null. */ 112 extern int stdin_null_flag; 113 114 /* Flag indicating that no shell has been requested */ 115 extern int no_shell_flag; 116 117 /* Flag indicating that ssh should daemonise after authentication is complete */ 118 extern int fork_after_authentication_flag; 119 120 /* Control socket */ 121 extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */ 122 123 /* 124 * Name of the host we are connecting to. This is the name given on the 125 * command line, or the Hostname specified for the user-supplied name in a 126 * configuration file. 127 */ 128 extern char *host; 129 130 /* 131 * If this field is not NULL, the ForwardAgent socket is this path and different 132 * instead of SSH_AUTH_SOCK. 133 */ 134 extern char *forward_agent_sock_path; 135 136 /* 137 * Flag to indicate that we have received a window change signal which has 138 * not yet been processed. This will cause a message indicating the new 139 * window size to be sent to the server a little later. This is volatile 140 * because this is updated in a signal handler. 141 */ 142 static volatile sig_atomic_t received_window_change_signal = 0; 143 static volatile sig_atomic_t received_signal = 0; 144 145 /* Time when backgrounded control master using ControlPersist should exit */ 146 static time_t control_persist_exit_time = 0; 147 148 /* Common data for the client loop code. */ 149 volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */ 150 static int last_was_cr; /* Last character was a newline. */ 151 static int exit_status; /* Used to store the command exit status. */ 152 static struct sshbuf *stderr_buffer; /* Used for final exit message. */ 153 static int connection_in; /* Connection to server (input). */ 154 static int connection_out; /* Connection to server (output). */ 155 static int need_rekeying; /* Set to non-zero if rekeying is requested. */ 156 static int session_closed; /* In SSH2: login session closed. */ 157 static u_int x11_refuse_time; /* If >0, refuse x11 opens after this time. */ 158 static time_t server_alive_time; /* Time to do server_alive_check */ 159 160 static void client_init_dispatch(struct ssh *ssh); 161 int session_ident = -1; 162 163 /* Track escape per proto2 channel */ 164 struct escape_filter_ctx { 165 int escape_pending; 166 int escape_char; 167 }; 168 169 /* Context for channel confirmation replies */ 170 struct channel_reply_ctx { 171 const char *request_type; 172 int id; 173 enum confirm_action action; 174 }; 175 176 /* Global request success/failure callbacks */ 177 /* XXX move to struct ssh? */ 178 struct global_confirm { 179 TAILQ_ENTRY(global_confirm) entry; 180 global_confirm_cb *cb; 181 void *ctx; 182 int ref_count; 183 }; 184 TAILQ_HEAD(global_confirms, global_confirm); 185 static struct global_confirms global_confirms = 186 TAILQ_HEAD_INITIALIZER(global_confirms); 187 188 void ssh_process_session2_setup(int, int, int, struct sshbuf *); 189 190 /* 191 * Signal handler for the window change signal (SIGWINCH). This just sets a 192 * flag indicating that the window has changed. 193 */ 194 /*ARGSUSED */ 195 static void 196 window_change_handler(int sig) 197 { 198 received_window_change_signal = 1; 199 } 200 201 /* 202 * Signal handler for signals that cause the program to terminate. These 203 * signals must be trapped to restore terminal modes. 204 */ 205 /*ARGSUSED */ 206 static void 207 signal_handler(int sig) 208 { 209 received_signal = sig; 210 quit_pending = 1; 211 } 212 213 /* 214 * Sets control_persist_exit_time to the absolute time when the 215 * backgrounded control master should exit due to expiry of the 216 * ControlPersist timeout. Sets it to 0 if we are not a backgrounded 217 * control master process, or if there is no ControlPersist timeout. 218 */ 219 static void 220 set_control_persist_exit_time(struct ssh *ssh) 221 { 222 if (muxserver_sock == -1 || !options.control_persist 223 || options.control_persist_timeout == 0) { 224 /* not using a ControlPersist timeout */ 225 control_persist_exit_time = 0; 226 } else if (channel_still_open(ssh)) { 227 /* some client connections are still open */ 228 if (control_persist_exit_time > 0) 229 debug2_f("cancel scheduled exit"); 230 control_persist_exit_time = 0; 231 } else if (control_persist_exit_time <= 0) { 232 /* a client connection has recently closed */ 233 control_persist_exit_time = monotime() + 234 (time_t)options.control_persist_timeout; 235 debug2_f("schedule exit in %d seconds", 236 options.control_persist_timeout); 237 } 238 /* else we are already counting down to the timeout */ 239 } 240 241 #define SSH_X11_VALID_DISPLAY_CHARS ":/.-_" 242 static int 243 client_x11_display_valid(const char *display) 244 { 245 size_t i, dlen; 246 247 if (display == NULL) 248 return 0; 249 250 dlen = strlen(display); 251 for (i = 0; i < dlen; i++) { 252 if (!isalnum((u_char)display[i]) && 253 strchr(SSH_X11_VALID_DISPLAY_CHARS, display[i]) == NULL) { 254 debug("Invalid character '%c' in DISPLAY", display[i]); 255 return 0; 256 } 257 } 258 return 1; 259 } 260 261 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1" 262 #define X11_TIMEOUT_SLACK 60 263 int 264 client_x11_get_proto(struct ssh *ssh, const char *display, 265 const char *xauth_path, u_int trusted, u_int timeout, 266 char **_proto, char **_data) 267 { 268 char *cmd, line[512], xdisplay[512]; 269 char xauthfile[PATH_MAX], xauthdir[PATH_MAX]; 270 static char proto[512], data[512]; 271 FILE *f; 272 int got_data = 0, generated = 0, do_unlink = 0, r; 273 struct stat st; 274 u_int now, x11_timeout_real; 275 276 *_proto = proto; 277 *_data = data; 278 proto[0] = data[0] = xauthfile[0] = xauthdir[0] = '\0'; 279 280 if (!client_x11_display_valid(display)) { 281 if (display != NULL) 282 logit("DISPLAY \"%s\" invalid; disabling X11 forwarding", 283 display); 284 return -1; 285 } 286 if (xauth_path != NULL && stat(xauth_path, &st) == -1) { 287 debug("No xauth program."); 288 xauth_path = NULL; 289 } 290 291 if (xauth_path != NULL) { 292 /* 293 * Handle FamilyLocal case where $DISPLAY does 294 * not match an authorization entry. For this we 295 * just try "xauth list unix:displaynum.screennum". 296 * XXX: "localhost" match to determine FamilyLocal 297 * is not perfect. 298 */ 299 if (strncmp(display, "localhost:", 10) == 0) { 300 if ((r = snprintf(xdisplay, sizeof(xdisplay), "unix:%s", 301 display + 10)) < 0 || 302 (size_t)r >= sizeof(xdisplay)) { 303 error_f("display name too long"); 304 return -1; 305 } 306 display = xdisplay; 307 } 308 if (trusted == 0) { 309 /* 310 * Generate an untrusted X11 auth cookie. 311 * 312 * The authentication cookie should briefly outlive 313 * ssh's willingness to forward X11 connections to 314 * avoid nasty fail-open behaviour in the X server. 315 */ 316 mktemp_proto(xauthdir, sizeof(xauthdir)); 317 if (mkdtemp(xauthdir) == NULL) { 318 error_f("mkdtemp: %s", strerror(errno)); 319 return -1; 320 } 321 do_unlink = 1; 322 if ((r = snprintf(xauthfile, sizeof(xauthfile), 323 "%s/xauthfile", xauthdir)) < 0 || 324 (size_t)r >= sizeof(xauthfile)) { 325 error_f("xauthfile path too long"); 326 rmdir(xauthdir); 327 return -1; 328 } 329 330 if (timeout == 0) { 331 /* auth doesn't time out */ 332 xasprintf(&cmd, "%s -f %s generate %s %s " 333 "untrusted 2>%s", 334 xauth_path, xauthfile, display, 335 SSH_X11_PROTO, _PATH_DEVNULL); 336 } else { 337 /* Add some slack to requested expiry */ 338 if (timeout < UINT_MAX - X11_TIMEOUT_SLACK) 339 x11_timeout_real = timeout + 340 X11_TIMEOUT_SLACK; 341 else { 342 /* Don't overflow on long timeouts */ 343 x11_timeout_real = UINT_MAX; 344 } 345 xasprintf(&cmd, "%s -f %s generate %s %s " 346 "untrusted timeout %u 2>%s", 347 xauth_path, xauthfile, display, 348 SSH_X11_PROTO, x11_timeout_real, 349 _PATH_DEVNULL); 350 } 351 debug2_f("xauth command: %s", cmd); 352 353 if (timeout != 0 && x11_refuse_time == 0) { 354 now = monotime() + 1; 355 if (UINT_MAX - timeout < now) 356 x11_refuse_time = UINT_MAX; 357 else 358 x11_refuse_time = now + timeout; 359 channel_set_x11_refuse_time(ssh, 360 x11_refuse_time); 361 } 362 if (system(cmd) == 0) 363 generated = 1; 364 free(cmd); 365 } 366 367 /* 368 * When in untrusted mode, we read the cookie only if it was 369 * successfully generated as an untrusted one in the step 370 * above. 371 */ 372 if (trusted || generated) { 373 xasprintf(&cmd, 374 "%s %s%s list %s 2>" _PATH_DEVNULL, 375 xauth_path, 376 generated ? "-f " : "" , 377 generated ? xauthfile : "", 378 display); 379 debug2("x11_get_proto: %s", cmd); 380 f = popen(cmd, "r"); 381 if (f && fgets(line, sizeof(line), f) && 382 sscanf(line, "%*s %511s %511s", proto, data) == 2) 383 got_data = 1; 384 if (f) 385 pclose(f); 386 free(cmd); 387 } 388 } 389 390 if (do_unlink) { 391 unlink(xauthfile); 392 rmdir(xauthdir); 393 } 394 395 /* Don't fall back to fake X11 data for untrusted forwarding */ 396 if (!trusted && !got_data) { 397 error("Warning: untrusted X11 forwarding setup failed: " 398 "xauth key data not generated"); 399 return -1; 400 } 401 402 /* 403 * If we didn't get authentication data, just make up some 404 * data. The forwarding code will check the validity of the 405 * response anyway, and substitute this data. The X11 406 * server, however, will ignore this fake data and use 407 * whatever authentication mechanisms it was using otherwise 408 * for the local connection. 409 */ 410 if (!got_data) { 411 u_int8_t rnd[16]; 412 u_int i; 413 414 logit("Warning: No xauth data; " 415 "using fake authentication data for X11 forwarding."); 416 strlcpy(proto, SSH_X11_PROTO, sizeof proto); 417 arc4random_buf(rnd, sizeof(rnd)); 418 for (i = 0; i < sizeof(rnd); i++) { 419 snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", 420 rnd[i]); 421 } 422 } 423 424 return 0; 425 } 426 427 /* 428 * Checks if the client window has changed, and sends a packet about it to 429 * the server if so. The actual change is detected elsewhere (by a software 430 * interrupt on Unix); this just checks the flag and sends a message if 431 * appropriate. 432 */ 433 434 static void 435 client_check_window_change(struct ssh *ssh) 436 { 437 if (!received_window_change_signal) 438 return; 439 received_window_change_signal = 0; 440 debug2_f("changed"); 441 channel_send_window_changes(ssh); 442 } 443 444 static int 445 client_global_request_reply(int type, u_int32_t seq, struct ssh *ssh) 446 { 447 struct global_confirm *gc; 448 449 if ((gc = TAILQ_FIRST(&global_confirms)) == NULL) 450 return 0; 451 if (gc->cb != NULL) 452 gc->cb(ssh, type, seq, gc->ctx); 453 if (--gc->ref_count <= 0) { 454 TAILQ_REMOVE(&global_confirms, gc, entry); 455 freezero(gc, sizeof(*gc)); 456 } 457 458 ssh_packet_set_alive_timeouts(ssh, 0); 459 return 0; 460 } 461 462 static void 463 schedule_server_alive_check(void) 464 { 465 if (options.server_alive_interval > 0) 466 server_alive_time = monotime() + options.server_alive_interval; 467 } 468 469 static void 470 server_alive_check(struct ssh *ssh) 471 { 472 int r; 473 474 if (ssh_packet_inc_alive_timeouts(ssh) > options.server_alive_count_max) { 475 logit("Timeout, server %s not responding.", host); 476 cleanup_exit(255); 477 } 478 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || 479 (r = sshpkt_put_cstring(ssh, "keepalive@openssh.com")) != 0 || 480 (r = sshpkt_put_u8(ssh, 1)) != 0 || /* boolean: want reply */ 481 (r = sshpkt_send(ssh)) != 0) 482 fatal_fr(r, "send packet"); 483 /* Insert an empty placeholder to maintain ordering */ 484 client_register_global_confirm(NULL, NULL); 485 schedule_server_alive_check(); 486 } 487 488 /* 489 * Waits until the client can do something (some data becomes available on 490 * one of the file descriptors). 491 */ 492 static void 493 client_wait_until_can_do_something(struct ssh *ssh, 494 fd_set **readsetp, fd_set **writesetp, 495 int *maxfdp, u_int *nallocp, int rekeying) 496 { 497 struct timeval tv, *tvp; 498 int timeout_secs; 499 time_t minwait_secs = 0, now = monotime(); 500 int r, ret; 501 502 /* Add any selections by the channel mechanism. */ 503 channel_prepare_select(ssh, readsetp, writesetp, maxfdp, 504 nallocp, &minwait_secs); 505 506 /* channel_prepare_select could have closed the last channel */ 507 if (session_closed && !channel_still_open(ssh) && 508 !ssh_packet_have_data_to_write(ssh)) { 509 /* clear mask since we did not call select() */ 510 memset(*readsetp, 0, *nallocp); 511 memset(*writesetp, 0, *nallocp); 512 return; 513 } 514 515 FD_SET(connection_in, *readsetp); 516 517 /* Select server connection if have data to write to the server. */ 518 if (ssh_packet_have_data_to_write(ssh)) 519 FD_SET(connection_out, *writesetp); 520 521 /* 522 * Wait for something to happen. This will suspend the process until 523 * some selected descriptor can be read, written, or has some other 524 * event pending, or a timeout expires. 525 */ 526 527 timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */ 528 if (options.server_alive_interval > 0) 529 timeout_secs = MAXIMUM(server_alive_time - now, 0); 530 if (options.rekey_interval > 0 && !rekeying) 531 timeout_secs = MINIMUM(timeout_secs, 532 ssh_packet_get_rekey_timeout(ssh)); 533 set_control_persist_exit_time(ssh); 534 if (control_persist_exit_time > 0) { 535 timeout_secs = MINIMUM(timeout_secs, 536 control_persist_exit_time - now); 537 if (timeout_secs < 0) 538 timeout_secs = 0; 539 } 540 if (minwait_secs != 0) 541 timeout_secs = MINIMUM(timeout_secs, (int)minwait_secs); 542 if (timeout_secs == INT_MAX) 543 tvp = NULL; 544 else { 545 tv.tv_sec = timeout_secs; 546 tv.tv_usec = 0; 547 tvp = &tv; 548 } 549 550 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); 551 if (ret == -1) { 552 /* 553 * We have to clear the select masks, because we return. 554 * We have to return, because the mainloop checks for the flags 555 * set by the signal handlers. 556 */ 557 memset(*readsetp, 0, *nallocp); 558 memset(*writesetp, 0, *nallocp); 559 if (errno == EINTR) 560 return; 561 /* Note: we might still have data in the buffers. */ 562 if ((r = sshbuf_putf(stderr_buffer, 563 "select: %s\r\n", strerror(errno))) != 0) 564 fatal_fr(r, "sshbuf_putf"); 565 quit_pending = 1; 566 } else if (options.server_alive_interval > 0 && !FD_ISSET(connection_in, 567 *readsetp) && monotime() >= server_alive_time) 568 /* 569 * ServerAlive check is needed. We can't rely on the select 570 * timing out since traffic on the client side such as port 571 * forwards can keep waking it up. 572 */ 573 server_alive_check(ssh); 574 } 575 576 static void 577 client_suspend_self(struct sshbuf *bin, struct sshbuf *bout, struct sshbuf *berr) 578 { 579 /* Flush stdout and stderr buffers. */ 580 if (sshbuf_len(bout) > 0) 581 atomicio(vwrite, fileno(stdout), sshbuf_mutable_ptr(bout), 582 sshbuf_len(bout)); 583 if (sshbuf_len(berr) > 0) 584 atomicio(vwrite, fileno(stderr), sshbuf_mutable_ptr(berr), 585 sshbuf_len(berr)); 586 587 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 588 589 sshbuf_reset(bin); 590 sshbuf_reset(bout); 591 sshbuf_reset(berr); 592 593 /* Send the suspend signal to the program itself. */ 594 kill(getpid(), SIGTSTP); 595 596 /* Reset window sizes in case they have changed */ 597 received_window_change_signal = 1; 598 599 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 600 } 601 602 static void 603 client_process_net_input(struct ssh *ssh, fd_set *readset) 604 { 605 char buf[8192]; 606 int r, len; 607 608 /* 609 * Read input from the server, and add any such data to the buffer of 610 * the packet subsystem. 611 */ 612 if (FD_ISSET(connection_in, readset)) { 613 schedule_server_alive_check(); 614 /* Read as much as possible. */ 615 len = read(connection_in, buf, sizeof(buf)); 616 if (len == 0) { 617 /* 618 * Received EOF. The remote host has closed the 619 * connection. 620 */ 621 if ((r = sshbuf_putf(stderr_buffer, 622 "Connection to %.300s closed by remote host.\r\n", 623 host)) != 0) 624 fatal_fr(r, "sshbuf_putf"); 625 quit_pending = 1; 626 return; 627 } 628 /* 629 * There is a kernel bug on Solaris that causes select to 630 * sometimes wake up even though there is no data available. 631 */ 632 if (len == -1 && (errno == EAGAIN || errno == EINTR)) 633 len = 0; 634 635 if (len == -1) { 636 /* 637 * An error has encountered. Perhaps there is a 638 * network problem. 639 */ 640 if ((r = sshbuf_putf(stderr_buffer, 641 "Read from remote host %.300s: %.100s\r\n", 642 host, strerror(errno))) != 0) 643 fatal_fr(r, "sshbuf_putf"); 644 quit_pending = 1; 645 return; 646 } 647 ssh_packet_process_incoming(ssh, buf, len); 648 } 649 } 650 651 static void 652 client_status_confirm(struct ssh *ssh, int type, Channel *c, void *ctx) 653 { 654 struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx; 655 char errmsg[256]; 656 int r, tochan; 657 658 /* 659 * If a TTY was explicitly requested, then a failure to allocate 660 * one is fatal. 661 */ 662 if (cr->action == CONFIRM_TTY && 663 (options.request_tty == REQUEST_TTY_FORCE || 664 options.request_tty == REQUEST_TTY_YES)) 665 cr->action = CONFIRM_CLOSE; 666 667 /* XXX suppress on mux _client_ quietmode */ 668 tochan = options.log_level >= SYSLOG_LEVEL_ERROR && 669 c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE; 670 671 if (type == SSH2_MSG_CHANNEL_SUCCESS) { 672 debug2("%s request accepted on channel %d", 673 cr->request_type, c->self); 674 } else if (type == SSH2_MSG_CHANNEL_FAILURE) { 675 if (tochan) { 676 snprintf(errmsg, sizeof(errmsg), 677 "%s request failed\r\n", cr->request_type); 678 } else { 679 snprintf(errmsg, sizeof(errmsg), 680 "%s request failed on channel %d", 681 cr->request_type, c->self); 682 } 683 /* If error occurred on primary session channel, then exit */ 684 if (cr->action == CONFIRM_CLOSE && c->self == session_ident) 685 fatal("%s", errmsg); 686 /* 687 * If error occurred on mux client, append to 688 * their stderr. 689 */ 690 if (tochan) { 691 debug3_f("channel %d: mux request: %s", c->self, 692 cr->request_type); 693 if ((r = sshbuf_put(c->extended, errmsg, 694 strlen(errmsg))) != 0) 695 fatal_fr(r, "sshbuf_put"); 696 } else 697 error("%s", errmsg); 698 if (cr->action == CONFIRM_TTY) { 699 /* 700 * If a TTY allocation error occurred, then arrange 701 * for the correct TTY to leave raw mode. 702 */ 703 if (c->self == session_ident) 704 leave_raw_mode(0); 705 else 706 mux_tty_alloc_failed(ssh, c); 707 } else if (cr->action == CONFIRM_CLOSE) { 708 chan_read_failed(ssh, c); 709 chan_write_failed(ssh, c); 710 } 711 } 712 free(cr); 713 } 714 715 static void 716 client_abandon_status_confirm(struct ssh *ssh, Channel *c, void *ctx) 717 { 718 free(ctx); 719 } 720 721 void 722 client_expect_confirm(struct ssh *ssh, int id, const char *request, 723 enum confirm_action action) 724 { 725 struct channel_reply_ctx *cr = xcalloc(1, sizeof(*cr)); 726 727 cr->request_type = request; 728 cr->action = action; 729 730 channel_register_status_confirm(ssh, id, client_status_confirm, 731 client_abandon_status_confirm, cr); 732 } 733 734 void 735 client_register_global_confirm(global_confirm_cb *cb, void *ctx) 736 { 737 struct global_confirm *gc, *last_gc; 738 739 /* Coalesce identical callbacks */ 740 last_gc = TAILQ_LAST(&global_confirms, global_confirms); 741 if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) { 742 if (++last_gc->ref_count >= INT_MAX) 743 fatal_f("last_gc->ref_count = %d", 744 last_gc->ref_count); 745 return; 746 } 747 748 gc = xcalloc(1, sizeof(*gc)); 749 gc->cb = cb; 750 gc->ctx = ctx; 751 gc->ref_count = 1; 752 TAILQ_INSERT_TAIL(&global_confirms, gc, entry); 753 } 754 755 static void 756 process_cmdline(struct ssh *ssh) 757 { 758 void (*handler)(int); 759 char *s, *cmd; 760 int ok, delete = 0, local = 0, remote = 0, dynamic = 0; 761 struct Forward fwd; 762 763 memset(&fwd, 0, sizeof(fwd)); 764 765 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 766 handler = ssh_signal(SIGINT, SIG_IGN); 767 cmd = s = read_passphrase("\r\nssh> ", RP_ECHO); 768 if (s == NULL) 769 goto out; 770 while (isspace((u_char)*s)) 771 s++; 772 if (*s == '-') 773 s++; /* Skip cmdline '-', if any */ 774 if (*s == '\0') 775 goto out; 776 777 if (*s == 'h' || *s == 'H' || *s == '?') { 778 logit("Commands:"); 779 logit(" -L[bind_address:]port:host:hostport " 780 "Request local forward"); 781 logit(" -R[bind_address:]port:host:hostport " 782 "Request remote forward"); 783 logit(" -D[bind_address:]port " 784 "Request dynamic forward"); 785 logit(" -KL[bind_address:]port " 786 "Cancel local forward"); 787 logit(" -KR[bind_address:]port " 788 "Cancel remote forward"); 789 logit(" -KD[bind_address:]port " 790 "Cancel dynamic forward"); 791 if (!options.permit_local_command) 792 goto out; 793 logit(" !args " 794 "Execute local command"); 795 goto out; 796 } 797 798 if (*s == '!' && options.permit_local_command) { 799 s++; 800 ssh_local_cmd(s); 801 goto out; 802 } 803 804 if (*s == 'K') { 805 delete = 1; 806 s++; 807 } 808 if (*s == 'L') 809 local = 1; 810 else if (*s == 'R') 811 remote = 1; 812 else if (*s == 'D') 813 dynamic = 1; 814 else { 815 logit("Invalid command."); 816 goto out; 817 } 818 819 while (isspace((u_char)*++s)) 820 ; 821 822 /* XXX update list of forwards in options */ 823 if (delete) { 824 /* We pass 1 for dynamicfwd to restrict to 1 or 2 fields. */ 825 if (!parse_forward(&fwd, s, 1, 0)) { 826 logit("Bad forwarding close specification."); 827 goto out; 828 } 829 if (remote) 830 ok = channel_request_rforward_cancel(ssh, &fwd) == 0; 831 else if (dynamic) 832 ok = channel_cancel_lport_listener(ssh, &fwd, 833 0, &options.fwd_opts) > 0; 834 else 835 ok = channel_cancel_lport_listener(ssh, &fwd, 836 CHANNEL_CANCEL_PORT_STATIC, 837 &options.fwd_opts) > 0; 838 if (!ok) { 839 logit("Unknown port forwarding."); 840 goto out; 841 } 842 logit("Canceled forwarding."); 843 } else { 844 if (!parse_forward(&fwd, s, dynamic, remote)) { 845 logit("Bad forwarding specification."); 846 goto out; 847 } 848 if (local || dynamic) { 849 if (!channel_setup_local_fwd_listener(ssh, &fwd, 850 &options.fwd_opts)) { 851 logit("Port forwarding failed."); 852 goto out; 853 } 854 } else { 855 if (channel_request_remote_forwarding(ssh, &fwd) < 0) { 856 logit("Port forwarding failed."); 857 goto out; 858 } 859 } 860 logit("Forwarding port."); 861 } 862 863 out: 864 ssh_signal(SIGINT, handler); 865 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 866 free(cmd); 867 free(fwd.listen_host); 868 free(fwd.listen_path); 869 free(fwd.connect_host); 870 free(fwd.connect_path); 871 } 872 873 /* reasons to suppress output of an escape command in help output */ 874 #define SUPPRESS_NEVER 0 /* never suppress, always show */ 875 #define SUPPRESS_MUXCLIENT 1 /* don't show in mux client sessions */ 876 #define SUPPRESS_MUXMASTER 2 /* don't show in mux master sessions */ 877 #define SUPPRESS_SYSLOG 4 /* don't show when logging to syslog */ 878 struct escape_help_text { 879 const char *cmd; 880 const char *text; 881 unsigned int flags; 882 }; 883 static struct escape_help_text esc_txt[] = { 884 {".", "terminate session", SUPPRESS_MUXMASTER}, 885 {".", "terminate connection (and any multiplexed sessions)", 886 SUPPRESS_MUXCLIENT}, 887 {"B", "send a BREAK to the remote system", SUPPRESS_NEVER}, 888 {"C", "open a command line", SUPPRESS_MUXCLIENT}, 889 {"R", "request rekey", SUPPRESS_NEVER}, 890 {"V/v", "decrease/increase verbosity (LogLevel)", SUPPRESS_MUXCLIENT}, 891 {"^Z", "suspend ssh", SUPPRESS_MUXCLIENT}, 892 {"#", "list forwarded connections", SUPPRESS_NEVER}, 893 {"&", "background ssh (when waiting for connections to terminate)", 894 SUPPRESS_MUXCLIENT}, 895 {"?", "this message", SUPPRESS_NEVER}, 896 }; 897 898 static void 899 print_escape_help(struct sshbuf *b, int escape_char, int mux_client, 900 int using_stderr) 901 { 902 unsigned int i, suppress_flags; 903 int r; 904 905 if ((r = sshbuf_putf(b, 906 "%c?\r\nSupported escape sequences:\r\n", escape_char)) != 0) 907 fatal_fr(r, "sshbuf_putf"); 908 909 suppress_flags = 910 (mux_client ? SUPPRESS_MUXCLIENT : 0) | 911 (mux_client ? 0 : SUPPRESS_MUXMASTER) | 912 (using_stderr ? 0 : SUPPRESS_SYSLOG); 913 914 for (i = 0; i < sizeof(esc_txt)/sizeof(esc_txt[0]); i++) { 915 if (esc_txt[i].flags & suppress_flags) 916 continue; 917 if ((r = sshbuf_putf(b, " %c%-3s - %s\r\n", 918 escape_char, esc_txt[i].cmd, esc_txt[i].text)) != 0) 919 fatal_fr(r, "sshbuf_putf"); 920 } 921 922 if ((r = sshbuf_putf(b, 923 " %c%c - send the escape character by typing it twice\r\n" 924 "(Note that escapes are only recognized immediately after " 925 "newline.)\r\n", escape_char, escape_char)) != 0) 926 fatal_fr(r, "sshbuf_putf"); 927 } 928 929 /* 930 * Process the characters one by one. 931 */ 932 static int 933 process_escapes(struct ssh *ssh, Channel *c, 934 struct sshbuf *bin, struct sshbuf *bout, struct sshbuf *berr, 935 char *buf, int len) 936 { 937 pid_t pid; 938 int r, bytes = 0; 939 u_int i; 940 u_char ch; 941 char *s; 942 struct escape_filter_ctx *efc = c->filter_ctx == NULL ? 943 NULL : (struct escape_filter_ctx *)c->filter_ctx; 944 945 if (c->filter_ctx == NULL) 946 return 0; 947 948 if (len <= 0) 949 return (0); 950 951 for (i = 0; i < (u_int)len; i++) { 952 /* Get one character at a time. */ 953 ch = buf[i]; 954 955 if (efc->escape_pending) { 956 /* We have previously seen an escape character. */ 957 /* Clear the flag now. */ 958 efc->escape_pending = 0; 959 960 /* Process the escaped character. */ 961 switch (ch) { 962 case '.': 963 /* Terminate the connection. */ 964 if ((r = sshbuf_putf(berr, "%c.\r\n", 965 efc->escape_char)) != 0) 966 fatal_fr(r, "sshbuf_putf"); 967 if (c && c->ctl_chan != -1) { 968 chan_read_failed(ssh, c); 969 chan_write_failed(ssh, c); 970 if (c->detach_user) { 971 c->detach_user(ssh, 972 c->self, NULL); 973 } 974 c->type = SSH_CHANNEL_ABANDONED; 975 sshbuf_reset(c->input); 976 chan_ibuf_empty(ssh, c); 977 return 0; 978 } else 979 quit_pending = 1; 980 return -1; 981 982 case 'Z' - 64: 983 /* XXX support this for mux clients */ 984 if (c && c->ctl_chan != -1) { 985 char b[16]; 986 noescape: 987 if (ch == 'Z' - 64) 988 snprintf(b, sizeof b, "^Z"); 989 else 990 snprintf(b, sizeof b, "%c", ch); 991 if ((r = sshbuf_putf(berr, 992 "%c%s escape not available to " 993 "multiplexed sessions\r\n", 994 efc->escape_char, b)) != 0) 995 fatal_fr(r, "sshbuf_putf"); 996 continue; 997 } 998 /* Suspend the program. Inform the user */ 999 if ((r = sshbuf_putf(berr, 1000 "%c^Z [suspend ssh]\r\n", 1001 efc->escape_char)) != 0) 1002 fatal_fr(r, "sshbuf_putf"); 1003 1004 /* Restore terminal modes and suspend. */ 1005 client_suspend_self(bin, bout, berr); 1006 1007 /* We have been continued. */ 1008 continue; 1009 1010 case 'B': 1011 if ((r = sshbuf_putf(berr, 1012 "%cB\r\n", efc->escape_char)) != 0) 1013 fatal_fr(r, "sshbuf_putf"); 1014 channel_request_start(ssh, c->self, "break", 0); 1015 if ((r = sshpkt_put_u32(ssh, 1000)) != 0 || 1016 (r = sshpkt_send(ssh)) != 0) 1017 fatal_fr(r, "send packet"); 1018 continue; 1019 1020 case 'R': 1021 if (ssh->compat & SSH_BUG_NOREKEY) 1022 logit("Server does not " 1023 "support re-keying"); 1024 else 1025 need_rekeying = 1; 1026 continue; 1027 1028 case 'V': 1029 /* FALLTHROUGH */ 1030 case 'v': 1031 if (c && c->ctl_chan != -1) 1032 goto noescape; 1033 if (!log_is_on_stderr()) { 1034 if ((r = sshbuf_putf(berr, 1035 "%c%c [Logging to syslog]\r\n", 1036 efc->escape_char, ch)) != 0) 1037 fatal_fr(r, "sshbuf_putf"); 1038 continue; 1039 } 1040 if (ch == 'V' && options.log_level > 1041 SYSLOG_LEVEL_QUIET) 1042 log_change_level(--options.log_level); 1043 if (ch == 'v' && options.log_level < 1044 SYSLOG_LEVEL_DEBUG3) 1045 log_change_level(++options.log_level); 1046 if ((r = sshbuf_putf(berr, 1047 "%c%c [LogLevel %s]\r\n", 1048 efc->escape_char, ch, 1049 log_level_name(options.log_level))) != 0) 1050 fatal_fr(r, "sshbuf_putf"); 1051 continue; 1052 1053 case '&': 1054 if (c && c->ctl_chan != -1) 1055 goto noescape; 1056 /* 1057 * Detach the program (continue to serve 1058 * connections, but put in background and no 1059 * more new connections). 1060 */ 1061 /* Restore tty modes. */ 1062 leave_raw_mode( 1063 options.request_tty == REQUEST_TTY_FORCE); 1064 1065 /* Stop listening for new connections. */ 1066 channel_stop_listening(ssh); 1067 1068 if ((r = sshbuf_putf(berr, "%c& " 1069 "[backgrounded]\n", efc->escape_char)) != 0) 1070 fatal_fr(r, "sshbuf_putf"); 1071 1072 /* Fork into background. */ 1073 pid = fork(); 1074 if (pid == -1) { 1075 error("fork: %.100s", strerror(errno)); 1076 continue; 1077 } 1078 if (pid != 0) { /* This is the parent. */ 1079 /* The parent just exits. */ 1080 exit(0); 1081 } 1082 /* The child continues serving connections. */ 1083 /* fake EOF on stdin */ 1084 if ((r = sshbuf_put_u8(bin, 4)) != 0) 1085 fatal_fr(r, "sshbuf_put_u8"); 1086 return -1; 1087 case '?': 1088 print_escape_help(berr, efc->escape_char, 1089 (c && c->ctl_chan != -1), 1090 log_is_on_stderr()); 1091 continue; 1092 1093 case '#': 1094 if ((r = sshbuf_putf(berr, "%c#\r\n", 1095 efc->escape_char)) != 0) 1096 fatal_fr(r, "sshbuf_putf"); 1097 s = channel_open_message(ssh); 1098 if ((r = sshbuf_put(berr, s, strlen(s))) != 0) 1099 fatal_fr(r, "sshbuf_put"); 1100 free(s); 1101 continue; 1102 1103 case 'C': 1104 if (c && c->ctl_chan != -1) 1105 goto noescape; 1106 process_cmdline(ssh); 1107 continue; 1108 1109 default: 1110 if (ch != efc->escape_char) { 1111 if ((r = sshbuf_put_u8(bin, 1112 efc->escape_char)) != 0) 1113 fatal_fr(r, "sshbuf_put_u8"); 1114 bytes++; 1115 } 1116 /* Escaped characters fall through here */ 1117 break; 1118 } 1119 } else { 1120 /* 1121 * The previous character was not an escape char. 1122 * Check if this is an escape. 1123 */ 1124 if (last_was_cr && ch == efc->escape_char) { 1125 /* 1126 * It is. Set the flag and continue to 1127 * next character. 1128 */ 1129 efc->escape_pending = 1; 1130 continue; 1131 } 1132 } 1133 1134 /* 1135 * Normal character. Record whether it was a newline, 1136 * and append it to the buffer. 1137 */ 1138 last_was_cr = (ch == '\r' || ch == '\n'); 1139 if ((r = sshbuf_put_u8(bin, ch)) != 0) 1140 fatal_fr(r, "sshbuf_put_u8"); 1141 bytes++; 1142 } 1143 return bytes; 1144 } 1145 1146 /* 1147 * Get packets from the connection input buffer, and process them as long as 1148 * there are packets available. 1149 * 1150 * Any unknown packets received during the actual 1151 * session cause the session to terminate. This is 1152 * intended to make debugging easier since no 1153 * confirmations are sent. Any compatible protocol 1154 * extensions must be negotiated during the 1155 * preparatory phase. 1156 */ 1157 1158 static void 1159 client_process_buffered_input_packets(struct ssh *ssh) 1160 { 1161 ssh_dispatch_run_fatal(ssh, DISPATCH_NONBLOCK, &quit_pending); 1162 } 1163 1164 /* scan buf[] for '~' before sending data to the peer */ 1165 1166 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */ 1167 void * 1168 client_new_escape_filter_ctx(int escape_char) 1169 { 1170 struct escape_filter_ctx *ret; 1171 1172 ret = xcalloc(1, sizeof(*ret)); 1173 ret->escape_pending = 0; 1174 ret->escape_char = escape_char; 1175 return (void *)ret; 1176 } 1177 1178 /* Free the escape filter context on channel free */ 1179 void 1180 client_filter_cleanup(struct ssh *ssh, int cid, void *ctx) 1181 { 1182 free(ctx); 1183 } 1184 1185 int 1186 client_simple_escape_filter(struct ssh *ssh, Channel *c, char *buf, int len) 1187 { 1188 if (c->extended_usage != CHAN_EXTENDED_WRITE) 1189 return 0; 1190 1191 return process_escapes(ssh, c, c->input, c->output, c->extended, 1192 buf, len); 1193 } 1194 1195 static void 1196 client_channel_closed(struct ssh *ssh, int id, void *arg) 1197 { 1198 channel_cancel_cleanup(ssh, id); 1199 session_closed = 1; 1200 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1201 } 1202 1203 /* 1204 * Implements the interactive session with the server. This is called after 1205 * the user has been authenticated, and a command has been started on the 1206 * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character 1207 * used as an escape character for terminating or suspending the session. 1208 */ 1209 int 1210 client_loop(struct ssh *ssh, int have_pty, int escape_char_arg, 1211 int ssh2_chan_id) 1212 { 1213 fd_set *readset = NULL, *writeset = NULL; 1214 double start_time, total_time; 1215 int r, max_fd = 0, max_fd2 = 0, len; 1216 u_int64_t ibytes, obytes; 1217 u_int nalloc = 0; 1218 1219 debug("Entering interactive session."); 1220 1221 if (options.control_master && 1222 !option_clear_or_none(options.control_path)) { 1223 debug("pledge: id"); 1224 if (pledge("stdio rpath wpath cpath unix inet dns recvfd sendfd proc exec id tty", 1225 NULL) == -1) 1226 fatal_f("pledge(): %s", strerror(errno)); 1227 1228 } else if (options.forward_x11 || options.permit_local_command) { 1229 debug("pledge: exec"); 1230 if (pledge("stdio rpath wpath cpath unix inet dns proc exec tty", 1231 NULL) == -1) 1232 fatal_f("pledge(): %s", strerror(errno)); 1233 1234 } else if (options.update_hostkeys) { 1235 debug("pledge: filesystem full"); 1236 if (pledge("stdio rpath wpath cpath unix inet dns proc tty", 1237 NULL) == -1) 1238 fatal_f("pledge(): %s", strerror(errno)); 1239 1240 } else if (!option_clear_or_none(options.proxy_command) || 1241 fork_after_authentication_flag) { 1242 debug("pledge: proc"); 1243 if (pledge("stdio cpath unix inet dns proc tty", NULL) == -1) 1244 fatal_f("pledge(): %s", strerror(errno)); 1245 1246 } else { 1247 debug("pledge: network"); 1248 if (pledge("stdio unix inet dns proc tty", NULL) == -1) 1249 fatal_f("pledge(): %s", strerror(errno)); 1250 } 1251 1252 start_time = monotime_double(); 1253 1254 /* Initialize variables. */ 1255 last_was_cr = 1; 1256 exit_status = -1; 1257 connection_in = ssh_packet_get_connection_in(ssh); 1258 connection_out = ssh_packet_get_connection_out(ssh); 1259 max_fd = MAXIMUM(connection_in, connection_out); 1260 1261 quit_pending = 0; 1262 1263 /* Initialize buffer. */ 1264 if ((stderr_buffer = sshbuf_new()) == NULL) 1265 fatal_f("sshbuf_new failed"); 1266 1267 client_init_dispatch(ssh); 1268 1269 /* 1270 * Set signal handlers, (e.g. to restore non-blocking mode) 1271 * but don't overwrite SIG_IGN, matches behaviour from rsh(1) 1272 */ 1273 if (ssh_signal(SIGHUP, SIG_IGN) != SIG_IGN) 1274 ssh_signal(SIGHUP, signal_handler); 1275 if (ssh_signal(SIGINT, SIG_IGN) != SIG_IGN) 1276 ssh_signal(SIGINT, signal_handler); 1277 if (ssh_signal(SIGQUIT, SIG_IGN) != SIG_IGN) 1278 ssh_signal(SIGQUIT, signal_handler); 1279 if (ssh_signal(SIGTERM, SIG_IGN) != SIG_IGN) 1280 ssh_signal(SIGTERM, signal_handler); 1281 ssh_signal(SIGWINCH, window_change_handler); 1282 1283 if (have_pty) 1284 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1285 1286 session_ident = ssh2_chan_id; 1287 if (session_ident != -1) { 1288 if (escape_char_arg != SSH_ESCAPECHAR_NONE) { 1289 channel_register_filter(ssh, session_ident, 1290 client_simple_escape_filter, NULL, 1291 client_filter_cleanup, 1292 client_new_escape_filter_ctx( 1293 escape_char_arg)); 1294 } 1295 channel_register_cleanup(ssh, session_ident, 1296 client_channel_closed, 0); 1297 } 1298 1299 schedule_server_alive_check(); 1300 1301 /* Main loop of the client for the interactive session mode. */ 1302 while (!quit_pending) { 1303 1304 /* Process buffered packets sent by the server. */ 1305 client_process_buffered_input_packets(ssh); 1306 1307 if (session_closed && !channel_still_open(ssh)) 1308 break; 1309 1310 if (ssh_packet_is_rekeying(ssh)) { 1311 debug("rekeying in progress"); 1312 } else if (need_rekeying) { 1313 /* manual rekey request */ 1314 debug("need rekeying"); 1315 if ((r = kex_start_rekex(ssh)) != 0) 1316 fatal_fr(r, "kex_start_rekex"); 1317 need_rekeying = 0; 1318 } else { 1319 /* 1320 * Make packets from buffered channel data, and 1321 * enqueue them for sending to the server. 1322 */ 1323 if (ssh_packet_not_very_much_data_to_write(ssh)) 1324 channel_output_poll(ssh); 1325 1326 /* 1327 * Check if the window size has changed, and buffer a 1328 * message about it to the server if so. 1329 */ 1330 client_check_window_change(ssh); 1331 1332 if (quit_pending) 1333 break; 1334 } 1335 /* 1336 * Wait until we have something to do (something becomes 1337 * available on one of the descriptors). 1338 */ 1339 max_fd2 = max_fd; 1340 client_wait_until_can_do_something(ssh, &readset, &writeset, 1341 &max_fd2, &nalloc, ssh_packet_is_rekeying(ssh)); 1342 1343 if (quit_pending) 1344 break; 1345 1346 /* Do channel operations unless rekeying in progress. */ 1347 if (!ssh_packet_is_rekeying(ssh)) 1348 channel_after_select(ssh, readset, writeset); 1349 1350 /* Buffer input from the connection. */ 1351 client_process_net_input(ssh, readset); 1352 1353 if (quit_pending) 1354 break; 1355 1356 /* 1357 * Send as much buffered packet data as possible to the 1358 * sender. 1359 */ 1360 if (FD_ISSET(connection_out, writeset)) { 1361 if ((r = ssh_packet_write_poll(ssh)) != 0) { 1362 sshpkt_fatal(ssh, r, 1363 "%s: ssh_packet_write_poll", __func__); 1364 } 1365 } 1366 1367 /* 1368 * If we are a backgrounded control master, and the 1369 * timeout has expired without any active client 1370 * connections, then quit. 1371 */ 1372 if (control_persist_exit_time > 0) { 1373 if (monotime() >= control_persist_exit_time) { 1374 debug("ControlPersist timeout expired"); 1375 break; 1376 } 1377 } 1378 } 1379 free(readset); 1380 free(writeset); 1381 1382 /* Terminate the session. */ 1383 1384 /* Stop watching for window change. */ 1385 ssh_signal(SIGWINCH, SIG_DFL); 1386 1387 if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 || 1388 (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_BY_APPLICATION)) != 0 || 1389 (r = sshpkt_put_cstring(ssh, "disconnected by user")) != 0 || 1390 (r = sshpkt_put_cstring(ssh, "")) != 0 || /* language tag */ 1391 (r = sshpkt_send(ssh)) != 0 || 1392 (r = ssh_packet_write_wait(ssh)) != 0) 1393 fatal_fr(r, "send disconnect"); 1394 1395 channel_free_all(ssh); 1396 1397 if (have_pty) 1398 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1399 1400 /* restore blocking io */ 1401 if (!isatty(fileno(stdin))) 1402 unset_nonblock(fileno(stdin)); 1403 if (!isatty(fileno(stdout))) 1404 unset_nonblock(fileno(stdout)); 1405 if (!isatty(fileno(stderr))) 1406 unset_nonblock(fileno(stderr)); 1407 1408 /* 1409 * If there was no shell or command requested, there will be no remote 1410 * exit status to be returned. In that case, clear error code if the 1411 * connection was deliberately terminated at this end. 1412 */ 1413 if (no_shell_flag && received_signal == SIGTERM) { 1414 received_signal = 0; 1415 exit_status = 0; 1416 } 1417 1418 if (received_signal) { 1419 verbose("Killed by signal %d.", (int) received_signal); 1420 cleanup_exit(255); 1421 } 1422 1423 /* 1424 * In interactive mode (with pseudo tty) display a message indicating 1425 * that the connection has been closed. 1426 */ 1427 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) { 1428 if ((r = sshbuf_putf(stderr_buffer, 1429 "Connection to %.64s closed.\r\n", host)) != 0) 1430 fatal_fr(r, "sshbuf_putf"); 1431 } 1432 1433 /* Output any buffered data for stderr. */ 1434 if (sshbuf_len(stderr_buffer) > 0) { 1435 len = atomicio(vwrite, fileno(stderr), 1436 (u_char *)sshbuf_ptr(stderr_buffer), 1437 sshbuf_len(stderr_buffer)); 1438 if (len < 0 || (u_int)len != sshbuf_len(stderr_buffer)) 1439 error("Write failed flushing stderr buffer."); 1440 else if ((r = sshbuf_consume(stderr_buffer, len)) != 0) 1441 fatal_fr(r, "sshbuf_consume"); 1442 } 1443 1444 /* Clear and free any buffers. */ 1445 sshbuf_free(stderr_buffer); 1446 1447 /* Report bytes transferred, and transfer rates. */ 1448 total_time = monotime_double() - start_time; 1449 ssh_packet_get_bytes(ssh, &ibytes, &obytes); 1450 verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds", 1451 (unsigned long long)obytes, (unsigned long long)ibytes, total_time); 1452 if (total_time > 0) 1453 verbose("Bytes per second: sent %.1f, received %.1f", 1454 obytes / total_time, ibytes / total_time); 1455 /* Return the exit status of the program. */ 1456 debug("Exit status %d", exit_status); 1457 return exit_status; 1458 } 1459 1460 /*********/ 1461 1462 static Channel * 1463 client_request_forwarded_tcpip(struct ssh *ssh, const char *request_type, 1464 int rchan, u_int rwindow, u_int rmaxpack) 1465 { 1466 Channel *c = NULL; 1467 struct sshbuf *b = NULL; 1468 char *listen_address, *originator_address; 1469 u_int listen_port, originator_port; 1470 int r; 1471 1472 /* Get rest of the packet */ 1473 if ((r = sshpkt_get_cstring(ssh, &listen_address, NULL)) != 0 || 1474 (r = sshpkt_get_u32(ssh, &listen_port)) != 0 || 1475 (r = sshpkt_get_cstring(ssh, &originator_address, NULL)) != 0 || 1476 (r = sshpkt_get_u32(ssh, &originator_port)) != 0 || 1477 (r = sshpkt_get_end(ssh)) != 0) 1478 fatal_fr(r, "parse packet"); 1479 1480 debug_f("listen %s port %d, originator %s port %d", 1481 listen_address, listen_port, originator_address, originator_port); 1482 1483 if (listen_port > 0xffff) 1484 error_f("invalid listen port"); 1485 else if (originator_port > 0xffff) 1486 error_f("invalid originator port"); 1487 else { 1488 c = channel_connect_by_listen_address(ssh, 1489 listen_address, listen_port, "forwarded-tcpip", 1490 originator_address); 1491 } 1492 1493 if (c != NULL && c->type == SSH_CHANNEL_MUX_CLIENT) { 1494 if ((b = sshbuf_new()) == NULL) { 1495 error_f("alloc reply"); 1496 goto out; 1497 } 1498 /* reconstruct and send to muxclient */ 1499 if ((r = sshbuf_put_u8(b, 0)) != 0 || /* padlen */ 1500 (r = sshbuf_put_u8(b, SSH2_MSG_CHANNEL_OPEN)) != 0 || 1501 (r = sshbuf_put_cstring(b, request_type)) != 0 || 1502 (r = sshbuf_put_u32(b, rchan)) != 0 || 1503 (r = sshbuf_put_u32(b, rwindow)) != 0 || 1504 (r = sshbuf_put_u32(b, rmaxpack)) != 0 || 1505 (r = sshbuf_put_cstring(b, listen_address)) != 0 || 1506 (r = sshbuf_put_u32(b, listen_port)) != 0 || 1507 (r = sshbuf_put_cstring(b, originator_address)) != 0 || 1508 (r = sshbuf_put_u32(b, originator_port)) != 0 || 1509 (r = sshbuf_put_stringb(c->output, b)) != 0) { 1510 error_fr(r, "compose for muxclient"); 1511 goto out; 1512 } 1513 } 1514 1515 out: 1516 sshbuf_free(b); 1517 free(originator_address); 1518 free(listen_address); 1519 return c; 1520 } 1521 1522 static Channel * 1523 client_request_forwarded_streamlocal(struct ssh *ssh, 1524 const char *request_type, int rchan) 1525 { 1526 Channel *c = NULL; 1527 char *listen_path; 1528 int r; 1529 1530 /* Get the remote path. */ 1531 if ((r = sshpkt_get_cstring(ssh, &listen_path, NULL)) != 0 || 1532 (r = sshpkt_get_string(ssh, NULL, NULL)) != 0 || /* reserved */ 1533 (r = sshpkt_get_end(ssh)) != 0) 1534 fatal_fr(r, "parse packet"); 1535 1536 debug_f("request: %s", listen_path); 1537 1538 c = channel_connect_by_listen_path(ssh, listen_path, 1539 "forwarded-streamlocal@openssh.com", "forwarded-streamlocal"); 1540 free(listen_path); 1541 return c; 1542 } 1543 1544 static Channel * 1545 client_request_x11(struct ssh *ssh, const char *request_type, int rchan) 1546 { 1547 Channel *c = NULL; 1548 char *originator; 1549 u_int originator_port; 1550 int r, sock; 1551 1552 if (!options.forward_x11) { 1553 error("Warning: ssh server tried X11 forwarding."); 1554 error("Warning: this is probably a break-in attempt by a " 1555 "malicious server."); 1556 return NULL; 1557 } 1558 if (x11_refuse_time != 0 && (u_int)monotime() >= x11_refuse_time) { 1559 verbose("Rejected X11 connection after ForwardX11Timeout " 1560 "expired"); 1561 return NULL; 1562 } 1563 if ((r = sshpkt_get_cstring(ssh, &originator, NULL)) != 0 || 1564 (r = sshpkt_get_u32(ssh, &originator_port)) != 0 || 1565 (r = sshpkt_get_end(ssh)) != 0) 1566 fatal_fr(r, "parse packet"); 1567 /* XXX check permission */ 1568 /* XXX range check originator port? */ 1569 debug("client_request_x11: request from %s %u", originator, 1570 originator_port); 1571 free(originator); 1572 sock = x11_connect_display(ssh); 1573 if (sock < 0) 1574 return NULL; 1575 c = channel_new(ssh, "x11", 1576 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 1577 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1); 1578 c->force_drain = 1; 1579 return c; 1580 } 1581 1582 static Channel * 1583 client_request_agent(struct ssh *ssh, const char *request_type, int rchan) 1584 { 1585 Channel *c = NULL; 1586 int r, sock; 1587 1588 if (!options.forward_agent) { 1589 error("Warning: ssh server tried agent forwarding."); 1590 error("Warning: this is probably a break-in attempt by a " 1591 "malicious server."); 1592 return NULL; 1593 } 1594 if (forward_agent_sock_path == NULL) { 1595 r = ssh_get_authentication_socket(&sock); 1596 } else { 1597 r = ssh_get_authentication_socket_path(forward_agent_sock_path, &sock); 1598 } 1599 if (r != 0) { 1600 if (r != SSH_ERR_AGENT_NOT_PRESENT) 1601 debug_fr(r, "ssh_get_authentication_socket"); 1602 return NULL; 1603 } 1604 c = channel_new(ssh, "authentication agent connection", 1605 SSH_CHANNEL_OPEN, sock, sock, -1, 1606 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, 1607 "authentication agent connection", 1); 1608 c->force_drain = 1; 1609 return c; 1610 } 1611 1612 char * 1613 client_request_tun_fwd(struct ssh *ssh, int tun_mode, 1614 int local_tun, int remote_tun, channel_open_fn *cb, void *cbctx) 1615 { 1616 Channel *c; 1617 int r, fd; 1618 char *ifname = NULL; 1619 1620 if (tun_mode == SSH_TUNMODE_NO) 1621 return 0; 1622 1623 debug("Requesting tun unit %d in mode %d", local_tun, tun_mode); 1624 1625 /* Open local tunnel device */ 1626 if ((fd = tun_open(local_tun, tun_mode, &ifname)) == -1) { 1627 error("Tunnel device open failed."); 1628 return NULL; 1629 } 1630 debug("Tunnel forwarding using interface %s", ifname); 1631 1632 c = channel_new(ssh, "tun", SSH_CHANNEL_OPENING, fd, fd, -1, 1633 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); 1634 c->datagram = 1; 1635 1636 if (cb != NULL) 1637 channel_register_open_confirm(ssh, c->self, cb, cbctx); 1638 1639 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN)) != 0 || 1640 (r = sshpkt_put_cstring(ssh, "tun@openssh.com")) != 0 || 1641 (r = sshpkt_put_u32(ssh, c->self)) != 0 || 1642 (r = sshpkt_put_u32(ssh, c->local_window_max)) != 0 || 1643 (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 || 1644 (r = sshpkt_put_u32(ssh, tun_mode)) != 0 || 1645 (r = sshpkt_put_u32(ssh, remote_tun)) != 0 || 1646 (r = sshpkt_send(ssh)) != 0) 1647 sshpkt_fatal(ssh, r, "%s: send reply", __func__); 1648 1649 return ifname; 1650 } 1651 1652 /* XXXX move to generic input handler */ 1653 static int 1654 client_input_channel_open(int type, u_int32_t seq, struct ssh *ssh) 1655 { 1656 Channel *c = NULL; 1657 char *ctype = NULL; 1658 int r; 1659 u_int rchan; 1660 size_t len; 1661 u_int rmaxpack, rwindow; 1662 1663 if ((r = sshpkt_get_cstring(ssh, &ctype, &len)) != 0 || 1664 (r = sshpkt_get_u32(ssh, &rchan)) != 0 || 1665 (r = sshpkt_get_u32(ssh, &rwindow)) != 0 || 1666 (r = sshpkt_get_u32(ssh, &rmaxpack)) != 0) 1667 goto out; 1668 1669 debug("client_input_channel_open: ctype %s rchan %d win %d max %d", 1670 ctype, rchan, rwindow, rmaxpack); 1671 1672 if (strcmp(ctype, "forwarded-tcpip") == 0) { 1673 c = client_request_forwarded_tcpip(ssh, ctype, rchan, rwindow, 1674 rmaxpack); 1675 } else if (strcmp(ctype, "forwarded-streamlocal@openssh.com") == 0) { 1676 c = client_request_forwarded_streamlocal(ssh, ctype, rchan); 1677 } else if (strcmp(ctype, "x11") == 0) { 1678 c = client_request_x11(ssh, ctype, rchan); 1679 } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) { 1680 c = client_request_agent(ssh, ctype, rchan); 1681 } 1682 if (c != NULL && c->type == SSH_CHANNEL_MUX_CLIENT) { 1683 debug3("proxied to downstream: %s", ctype); 1684 } else if (c != NULL) { 1685 debug("confirm %s", ctype); 1686 c->remote_id = rchan; 1687 c->have_remote_id = 1; 1688 c->remote_window = rwindow; 1689 c->remote_maxpacket = rmaxpack; 1690 if (c->type != SSH_CHANNEL_CONNECTING) { 1691 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 || 1692 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 || 1693 (r = sshpkt_put_u32(ssh, c->self)) != 0 || 1694 (r = sshpkt_put_u32(ssh, c->local_window)) != 0 || 1695 (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 || 1696 (r = sshpkt_send(ssh)) != 0) 1697 sshpkt_fatal(ssh, r, "%s: send reply", __func__); 1698 } 1699 } else { 1700 debug("failure %s", ctype); 1701 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE)) != 0 || 1702 (r = sshpkt_put_u32(ssh, rchan)) != 0 || 1703 (r = sshpkt_put_u32(ssh, SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED)) != 0 || 1704 (r = sshpkt_put_cstring(ssh, "open failed")) != 0 || 1705 (r = sshpkt_put_cstring(ssh, "")) != 0 || 1706 (r = sshpkt_send(ssh)) != 0) 1707 sshpkt_fatal(ssh, r, "%s: send failure", __func__); 1708 } 1709 r = 0; 1710 out: 1711 free(ctype); 1712 return r; 1713 } 1714 1715 static int 1716 client_input_channel_req(int type, u_int32_t seq, struct ssh *ssh) 1717 { 1718 Channel *c = NULL; 1719 char *rtype = NULL; 1720 u_char reply; 1721 u_int id, exitval; 1722 int r, success = 0; 1723 1724 if ((r = sshpkt_get_u32(ssh, &id)) != 0) 1725 return r; 1726 if (id <= INT_MAX) 1727 c = channel_lookup(ssh, id); 1728 if (channel_proxy_upstream(c, type, seq, ssh)) 1729 return 0; 1730 if ((r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 || 1731 (r = sshpkt_get_u8(ssh, &reply)) != 0) 1732 goto out; 1733 1734 debug("client_input_channel_req: channel %u rtype %s reply %d", 1735 id, rtype, reply); 1736 1737 if (c == NULL) { 1738 error("client_input_channel_req: channel %d: " 1739 "unknown channel", id); 1740 } else if (strcmp(rtype, "eow@openssh.com") == 0) { 1741 if ((r = sshpkt_get_end(ssh)) != 0) 1742 goto out; 1743 chan_rcvd_eow(ssh, c); 1744 } else if (strcmp(rtype, "exit-status") == 0) { 1745 if ((r = sshpkt_get_u32(ssh, &exitval)) != 0) 1746 goto out; 1747 if (c->ctl_chan != -1) { 1748 mux_exit_message(ssh, c, exitval); 1749 success = 1; 1750 } else if ((int)id == session_ident) { 1751 /* Record exit value of local session */ 1752 success = 1; 1753 exit_status = exitval; 1754 } else { 1755 /* Probably for a mux channel that has already closed */ 1756 debug_f("no sink for exit-status on channel %d", 1757 id); 1758 } 1759 if ((r = sshpkt_get_end(ssh)) != 0) 1760 goto out; 1761 } 1762 if (reply && c != NULL && !(c->flags & CHAN_CLOSE_SENT)) { 1763 if (!c->have_remote_id) 1764 fatal_f("channel %d: no remote_id", c->self); 1765 if ((r = sshpkt_start(ssh, success ? 1766 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE)) != 0 || 1767 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 || 1768 (r = sshpkt_send(ssh)) != 0) 1769 sshpkt_fatal(ssh, r, "%s: send failure", __func__); 1770 } 1771 r = 0; 1772 out: 1773 free(rtype); 1774 return r; 1775 } 1776 1777 struct hostkeys_update_ctx { 1778 /* The hostname and (optionally) IP address string for the server */ 1779 char *host_str, *ip_str; 1780 1781 /* 1782 * Keys received from the server and a flag for each indicating 1783 * whether they already exist in known_hosts. 1784 * keys_match is filled in by hostkeys_find() and later (for new 1785 * keys) by client_global_hostkeys_private_confirm(). 1786 */ 1787 struct sshkey **keys; 1788 u_int *keys_match; /* mask of HKF_MATCH_* from hostfile.h */ 1789 int *keys_verified; /* flag for new keys verified by server */ 1790 size_t nkeys, nnew, nincomplete; /* total, new keys, incomplete match */ 1791 1792 /* 1793 * Keys that are in known_hosts, but were not present in the update 1794 * from the server (i.e. scheduled to be deleted). 1795 * Filled in by hostkeys_find(). 1796 */ 1797 struct sshkey **old_keys; 1798 size_t nold; 1799 1800 /* Various special cases. */ 1801 int complex_hostspec; /* wildcard or manual pattern-list host name */ 1802 int ca_available; /* saw CA key for this host */ 1803 int old_key_seen; /* saw old key with other name/addr */ 1804 int other_name_seen; /* saw key with other name/addr */ 1805 }; 1806 1807 static void 1808 hostkeys_update_ctx_free(struct hostkeys_update_ctx *ctx) 1809 { 1810 size_t i; 1811 1812 if (ctx == NULL) 1813 return; 1814 for (i = 0; i < ctx->nkeys; i++) 1815 sshkey_free(ctx->keys[i]); 1816 free(ctx->keys); 1817 free(ctx->keys_match); 1818 free(ctx->keys_verified); 1819 for (i = 0; i < ctx->nold; i++) 1820 sshkey_free(ctx->old_keys[i]); 1821 free(ctx->old_keys); 1822 free(ctx->host_str); 1823 free(ctx->ip_str); 1824 free(ctx); 1825 } 1826 1827 /* 1828 * Returns non-zero if a known_hosts hostname list is not of a form that 1829 * can be handled by UpdateHostkeys. These include wildcard hostnames and 1830 * hostnames lists that do not follow the form host[,ip]. 1831 */ 1832 static int 1833 hostspec_is_complex(const char *hosts) 1834 { 1835 char *cp; 1836 1837 /* wildcard */ 1838 if (strchr(hosts, '*') != NULL || strchr(hosts, '?') != NULL) 1839 return 1; 1840 /* single host/ip = ok */ 1841 if ((cp = strchr(hosts, ',')) == NULL) 1842 return 0; 1843 /* more than two entries on the line */ 1844 if (strchr(cp + 1, ',') != NULL) 1845 return 1; 1846 /* XXX maybe parse cp+1 and ensure it is an IP? */ 1847 return 0; 1848 } 1849 1850 /* callback to search for ctx->keys in known_hosts */ 1851 static int 1852 hostkeys_find(struct hostkey_foreach_line *l, void *_ctx) 1853 { 1854 struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx; 1855 size_t i; 1856 struct sshkey **tmp; 1857 1858 if (l->key == NULL) 1859 return 0; 1860 if (l->status != HKF_STATUS_MATCHED) { 1861 /* Record if one of the keys appears on a non-matching line */ 1862 for (i = 0; i < ctx->nkeys; i++) { 1863 if (sshkey_equal(l->key, ctx->keys[i])) { 1864 ctx->other_name_seen = 1; 1865 debug3_f("found %s key under different " 1866 "name/addr at %s:%ld", 1867 sshkey_ssh_name(ctx->keys[i]), 1868 l->path, l->linenum); 1869 return 0; 1870 } 1871 } 1872 return 0; 1873 } 1874 /* Don't proceed if revocation or CA markers are present */ 1875 /* XXX relax this */ 1876 if (l->marker != MRK_NONE) { 1877 debug3_f("hostkeys file %s:%ld has CA/revocation marker", 1878 l->path, l->linenum); 1879 ctx->complex_hostspec = 1; 1880 return 0; 1881 } 1882 1883 /* If CheckHostIP is enabled, then check for mismatched hostname/addr */ 1884 if (ctx->ip_str != NULL && strchr(l->hosts, ',') != NULL) { 1885 if ((l->match & HKF_MATCH_HOST) == 0) { 1886 /* Record if address matched a different hostname. */ 1887 ctx->other_name_seen = 1; 1888 debug3_f("found address %s against different hostname " 1889 "at %s:%ld", ctx->ip_str, l->path, l->linenum); 1890 return 0; 1891 } else if ((l->match & HKF_MATCH_IP) == 0) { 1892 /* Record if hostname matched a different address. */ 1893 ctx->other_name_seen = 1; 1894 debug3_f("found hostname %s against different address " 1895 "at %s:%ld", ctx->host_str, l->path, l->linenum); 1896 } 1897 } 1898 1899 /* 1900 * UpdateHostkeys is skipped for wildcard host names and hostnames 1901 * that contain more than two entries (ssh never writes these). 1902 */ 1903 if (hostspec_is_complex(l->hosts)) { 1904 debug3_f("hostkeys file %s:%ld complex host specification", 1905 l->path, l->linenum); 1906 ctx->complex_hostspec = 1; 1907 return 0; 1908 } 1909 1910 /* Mark off keys we've already seen for this host */ 1911 for (i = 0; i < ctx->nkeys; i++) { 1912 if (!sshkey_equal(l->key, ctx->keys[i])) 1913 continue; 1914 debug3_f("found %s key at %s:%ld", 1915 sshkey_ssh_name(ctx->keys[i]), l->path, l->linenum); 1916 ctx->keys_match[i] |= l->match; 1917 return 0; 1918 } 1919 /* This line contained a key that not offered by the server */ 1920 debug3_f("deprecated %s key at %s:%ld", sshkey_ssh_name(l->key), 1921 l->path, l->linenum); 1922 if ((tmp = recallocarray(ctx->old_keys, ctx->nold, ctx->nold + 1, 1923 sizeof(*ctx->old_keys))) == NULL) 1924 fatal_f("recallocarray failed nold = %zu", ctx->nold); 1925 ctx->old_keys = tmp; 1926 ctx->old_keys[ctx->nold++] = l->key; 1927 l->key = NULL; 1928 1929 return 0; 1930 } 1931 1932 /* callback to search for ctx->old_keys in known_hosts under other names */ 1933 static int 1934 hostkeys_check_old(struct hostkey_foreach_line *l, void *_ctx) 1935 { 1936 struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx; 1937 size_t i; 1938 int hashed; 1939 1940 /* only care about lines that *don't* match the active host spec */ 1941 if (l->status == HKF_STATUS_MATCHED || l->key == NULL) 1942 return 0; 1943 1944 hashed = l->match & (HKF_MATCH_HOST_HASHED|HKF_MATCH_IP_HASHED); 1945 for (i = 0; i < ctx->nold; i++) { 1946 if (!sshkey_equal(l->key, ctx->old_keys[i])) 1947 continue; 1948 debug3_f("found deprecated %s key at %s:%ld as %s", 1949 sshkey_ssh_name(ctx->keys[i]), l->path, l->linenum, 1950 hashed ? "[HASHED]" : l->hosts); 1951 ctx->old_key_seen = 1; 1952 break; 1953 } 1954 return 0; 1955 } 1956 1957 /* 1958 * Check known_hosts files for deprecated keys under other names. Returns 0 1959 * on success or -1 on failure. Updates ctx->old_key_seen if deprecated keys 1960 * exist under names other than the active hostname/IP. 1961 */ 1962 static int 1963 check_old_keys_othernames(struct hostkeys_update_ctx *ctx) 1964 { 1965 size_t i; 1966 int r; 1967 1968 debug2_f("checking for %zu deprecated keys", ctx->nold); 1969 for (i = 0; i < options.num_user_hostfiles; i++) { 1970 debug3_f("searching %s for %s / %s", 1971 options.user_hostfiles[i], ctx->host_str, 1972 ctx->ip_str ? ctx->ip_str : "(none)"); 1973 if ((r = hostkeys_foreach(options.user_hostfiles[i], 1974 hostkeys_check_old, ctx, ctx->host_str, ctx->ip_str, 1975 HKF_WANT_PARSE_KEY, 0)) != 0) { 1976 if (r == SSH_ERR_SYSTEM_ERROR && errno == ENOENT) { 1977 debug_f("hostkeys file %s does not exist", 1978 options.user_hostfiles[i]); 1979 continue; 1980 } 1981 error_fr(r, "hostkeys_foreach failed for %s", 1982 options.user_hostfiles[i]); 1983 return -1; 1984 } 1985 } 1986 return 0; 1987 } 1988 1989 static void 1990 hostkey_change_preamble(LogLevel loglevel) 1991 { 1992 do_log2(loglevel, "The server has updated its host keys."); 1993 do_log2(loglevel, "These changes were verified by the server's " 1994 "existing trusted key."); 1995 } 1996 1997 static void 1998 update_known_hosts(struct hostkeys_update_ctx *ctx) 1999 { 2000 int r, was_raw = 0, first = 1; 2001 int asking = options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK; 2002 LogLevel loglevel = asking ? SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_VERBOSE; 2003 char *fp, *response; 2004 size_t i; 2005 struct stat sb; 2006 2007 for (i = 0; i < ctx->nkeys; i++) { 2008 if (!ctx->keys_verified[i]) 2009 continue; 2010 if ((fp = sshkey_fingerprint(ctx->keys[i], 2011 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) 2012 fatal_f("sshkey_fingerprint failed"); 2013 if (first && asking) 2014 hostkey_change_preamble(loglevel); 2015 do_log2(loglevel, "Learned new hostkey: %s %s", 2016 sshkey_type(ctx->keys[i]), fp); 2017 first = 0; 2018 free(fp); 2019 } 2020 for (i = 0; i < ctx->nold; i++) { 2021 if ((fp = sshkey_fingerprint(ctx->old_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, "Deprecating obsolete hostkey: %s %s", 2027 sshkey_type(ctx->old_keys[i]), fp); 2028 first = 0; 2029 free(fp); 2030 } 2031 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { 2032 if (get_saved_tio() != NULL) { 2033 leave_raw_mode(1); 2034 was_raw = 1; 2035 } 2036 response = NULL; 2037 for (i = 0; !quit_pending && i < 3; i++) { 2038 free(response); 2039 response = read_passphrase("Accept updated hostkeys? " 2040 "(yes/no): ", RP_ECHO); 2041 if (strcasecmp(response, "yes") == 0) 2042 break; 2043 else if (quit_pending || response == NULL || 2044 strcasecmp(response, "no") == 0) { 2045 options.update_hostkeys = 0; 2046 break; 2047 } else { 2048 do_log2(loglevel, "Please enter " 2049 "\"yes\" or \"no\""); 2050 } 2051 } 2052 if (quit_pending || i >= 3 || response == NULL) 2053 options.update_hostkeys = 0; 2054 free(response); 2055 if (was_raw) 2056 enter_raw_mode(1); 2057 } 2058 if (options.update_hostkeys == 0) 2059 return; 2060 /* 2061 * Now that all the keys are verified, we can go ahead and replace 2062 * them in known_hosts (assuming SSH_UPDATE_HOSTKEYS_ASK didn't 2063 * cancel the operation). 2064 */ 2065 for (i = 0; i < options.num_user_hostfiles; i++) { 2066 /* 2067 * NB. keys are only added to hostfiles[0], for the rest we 2068 * just delete the hostname entries. 2069 */ 2070 if (stat(options.user_hostfiles[i], &sb) != 0) { 2071 if (errno == ENOENT) { 2072 debug_f("known hosts file %s does not " 2073 "exist", options.user_hostfiles[i]); 2074 } else { 2075 error_f("known hosts file %s " 2076 "inaccessible: %s", 2077 options.user_hostfiles[i], strerror(errno)); 2078 } 2079 continue; 2080 } 2081 if ((r = hostfile_replace_entries(options.user_hostfiles[i], 2082 ctx->host_str, ctx->ip_str, 2083 i == 0 ? ctx->keys : NULL, i == 0 ? ctx->nkeys : 0, 2084 options.hash_known_hosts, 0, 2085 options.fingerprint_hash)) != 0) { 2086 error_fr(r, "hostfile_replace_entries failed for %s", 2087 options.user_hostfiles[i]); 2088 } 2089 } 2090 } 2091 2092 static void 2093 client_global_hostkeys_private_confirm(struct ssh *ssh, int type, 2094 u_int32_t seq, void *_ctx) 2095 { 2096 struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx; 2097 size_t i, ndone; 2098 struct sshbuf *signdata; 2099 int r, kexsigtype, use_kexsigtype; 2100 const u_char *sig; 2101 size_t siglen; 2102 2103 if (ctx->nnew == 0) 2104 fatal_f("ctx->nnew == 0"); /* sanity */ 2105 if (type != SSH2_MSG_REQUEST_SUCCESS) { 2106 error("Server failed to confirm ownership of " 2107 "private host keys"); 2108 hostkeys_update_ctx_free(ctx); 2109 return; 2110 } 2111 kexsigtype = sshkey_type_plain( 2112 sshkey_type_from_name(ssh->kex->hostkey_alg)); 2113 2114 if ((signdata = sshbuf_new()) == NULL) 2115 fatal_f("sshbuf_new failed"); 2116 /* 2117 * Expect a signature for each of the ctx->nnew private keys we 2118 * haven't seen before. They will be in the same order as the 2119 * ctx->keys where the corresponding ctx->keys_match[i] == 0. 2120 */ 2121 for (ndone = i = 0; i < ctx->nkeys; i++) { 2122 if (ctx->keys_match[i]) 2123 continue; 2124 /* Prepare data to be signed: session ID, unique string, key */ 2125 sshbuf_reset(signdata); 2126 if ( (r = sshbuf_put_cstring(signdata, 2127 "hostkeys-prove-00@openssh.com")) != 0 || 2128 (r = sshbuf_put_stringb(signdata, 2129 ssh->kex->session_id)) != 0 || 2130 (r = sshkey_puts(ctx->keys[i], signdata)) != 0) 2131 fatal_fr(r, "compose signdata"); 2132 /* Extract and verify signature */ 2133 if ((r = sshpkt_get_string_direct(ssh, &sig, &siglen)) != 0) { 2134 error_fr(r, "parse sig"); 2135 goto out; 2136 } 2137 /* 2138 * For RSA keys, prefer to use the signature type negotiated 2139 * during KEX to the default (SHA1). 2140 */ 2141 use_kexsigtype = kexsigtype == KEY_RSA && 2142 sshkey_type_plain(ctx->keys[i]->type) == KEY_RSA; 2143 debug3_f("verify %s key %zu using %s sigalg", 2144 sshkey_type(ctx->keys[i]), i, 2145 use_kexsigtype ? ssh->kex->hostkey_alg : NULL); 2146 if ((r = sshkey_verify(ctx->keys[i], sig, siglen, 2147 sshbuf_ptr(signdata), sshbuf_len(signdata), 2148 use_kexsigtype ? ssh->kex->hostkey_alg : NULL, 0, 2149 NULL)) != 0) { 2150 error_fr(r, "server gave bad signature for %s key %zu", 2151 sshkey_type(ctx->keys[i]), i); 2152 goto out; 2153 } 2154 /* Key is good. Mark it as 'seen' */ 2155 ctx->keys_verified[i] = 1; 2156 ndone++; 2157 } 2158 /* Shouldn't happen */ 2159 if (ndone != ctx->nnew) 2160 fatal_f("ndone != ctx->nnew (%zu / %zu)", ndone, ctx->nnew); 2161 if ((r = sshpkt_get_end(ssh)) != 0) { 2162 error_f("protocol error"); 2163 goto out; 2164 } 2165 2166 /* Make the edits to known_hosts */ 2167 update_known_hosts(ctx); 2168 out: 2169 hostkeys_update_ctx_free(ctx); 2170 } 2171 2172 /* 2173 * Returns non-zero if the key is accepted by HostkeyAlgorithms. 2174 * Made slightly less trivial by the multiple RSA signature algorithm names. 2175 */ 2176 static int 2177 key_accepted_by_hostkeyalgs(const struct sshkey *key) 2178 { 2179 const char *ktype = sshkey_ssh_name(key); 2180 const char *hostkeyalgs = options.hostkeyalgorithms; 2181 2182 if (key == NULL || key->type == KEY_UNSPEC) 2183 return 0; 2184 if (key->type == KEY_RSA && 2185 (match_pattern_list("rsa-sha2-256", hostkeyalgs, 0) == 1 || 2186 match_pattern_list("rsa-sha2-512", hostkeyalgs, 0) == 1)) 2187 return 1; 2188 return match_pattern_list(ktype, hostkeyalgs, 0) == 1; 2189 } 2190 2191 /* 2192 * Handle hostkeys-00@openssh.com global request to inform the client of all 2193 * the server's hostkeys. The keys are checked against the user's 2194 * HostkeyAlgorithms preference before they are accepted. 2195 */ 2196 static int 2197 client_input_hostkeys(struct ssh *ssh) 2198 { 2199 const u_char *blob = NULL; 2200 size_t i, len = 0; 2201 struct sshbuf *buf = NULL; 2202 struct sshkey *key = NULL, **tmp; 2203 int r; 2204 char *fp; 2205 static int hostkeys_seen = 0; /* XXX use struct ssh */ 2206 extern struct sockaddr_storage hostaddr; /* XXX from ssh.c */ 2207 struct hostkeys_update_ctx *ctx = NULL; 2208 u_int want; 2209 2210 if (hostkeys_seen) 2211 fatal_f("server already sent hostkeys"); 2212 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK && 2213 options.batch_mode) 2214 return 1; /* won't ask in batchmode, so don't even try */ 2215 if (!options.update_hostkeys || options.num_user_hostfiles <= 0) 2216 return 1; 2217 2218 ctx = xcalloc(1, sizeof(*ctx)); 2219 while (ssh_packet_remaining(ssh) > 0) { 2220 sshkey_free(key); 2221 key = NULL; 2222 if ((r = sshpkt_get_string_direct(ssh, &blob, &len)) != 0) { 2223 error_fr(r, "parse key"); 2224 goto out; 2225 } 2226 if ((r = sshkey_from_blob(blob, len, &key)) != 0) { 2227 do_log2_fr(r, r == SSH_ERR_KEY_TYPE_UNKNOWN ? 2228 SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_ERROR, 2229 "convert key"); 2230 continue; 2231 } 2232 fp = sshkey_fingerprint(key, options.fingerprint_hash, 2233 SSH_FP_DEFAULT); 2234 debug3_f("received %s key %s", sshkey_type(key), fp); 2235 free(fp); 2236 2237 if (!key_accepted_by_hostkeyalgs(key)) { 2238 debug3_f("%s key not permitted by " 2239 "HostkeyAlgorithms", sshkey_ssh_name(key)); 2240 continue; 2241 } 2242 /* Skip certs */ 2243 if (sshkey_is_cert(key)) { 2244 debug3_f("%s key is a certificate; skipping", 2245 sshkey_ssh_name(key)); 2246 continue; 2247 } 2248 /* Ensure keys are unique */ 2249 for (i = 0; i < ctx->nkeys; i++) { 2250 if (sshkey_equal(key, ctx->keys[i])) { 2251 error_f("received duplicated %s host key", 2252 sshkey_ssh_name(key)); 2253 goto out; 2254 } 2255 } 2256 /* Key is good, record it */ 2257 if ((tmp = recallocarray(ctx->keys, ctx->nkeys, ctx->nkeys + 1, 2258 sizeof(*ctx->keys))) == NULL) 2259 fatal_f("recallocarray failed nkeys = %zu", 2260 ctx->nkeys); 2261 ctx->keys = tmp; 2262 ctx->keys[ctx->nkeys++] = key; 2263 key = NULL; 2264 } 2265 2266 if (ctx->nkeys == 0) { 2267 debug_f("server sent no hostkeys"); 2268 goto out; 2269 } 2270 2271 if ((ctx->keys_match = calloc(ctx->nkeys, 2272 sizeof(*ctx->keys_match))) == NULL || 2273 (ctx->keys_verified = calloc(ctx->nkeys, 2274 sizeof(*ctx->keys_verified))) == NULL) 2275 fatal_f("calloc failed"); 2276 2277 get_hostfile_hostname_ipaddr(host, 2278 options.check_host_ip ? (struct sockaddr *)&hostaddr : NULL, 2279 options.port, &ctx->host_str, 2280 options.check_host_ip ? &ctx->ip_str : NULL); 2281 2282 /* Find which keys we already know about. */ 2283 for (i = 0; i < options.num_user_hostfiles; i++) { 2284 debug_f("searching %s for %s / %s", 2285 options.user_hostfiles[i], ctx->host_str, 2286 ctx->ip_str ? ctx->ip_str : "(none)"); 2287 if ((r = hostkeys_foreach(options.user_hostfiles[i], 2288 hostkeys_find, ctx, ctx->host_str, ctx->ip_str, 2289 HKF_WANT_PARSE_KEY, 0)) != 0) { 2290 if (r == SSH_ERR_SYSTEM_ERROR && errno == ENOENT) { 2291 debug_f("hostkeys file %s does not exist", 2292 options.user_hostfiles[i]); 2293 continue; 2294 } 2295 error_fr(r, "hostkeys_foreach failed for %s", 2296 options.user_hostfiles[i]); 2297 goto out; 2298 } 2299 } 2300 2301 /* Figure out if we have any new keys to add */ 2302 ctx->nnew = ctx->nincomplete = 0; 2303 want = HKF_MATCH_HOST | ( options.check_host_ip ? HKF_MATCH_IP : 0); 2304 for (i = 0; i < ctx->nkeys; i++) { 2305 if (ctx->keys_match[i] == 0) 2306 ctx->nnew++; 2307 if ((ctx->keys_match[i] & want) != want) 2308 ctx->nincomplete++; 2309 } 2310 2311 debug3_f("%zu server keys: %zu new, %zu retained, " 2312 "%zu incomplete match. %zu to remove", ctx->nkeys, ctx->nnew, 2313 ctx->nkeys - ctx->nnew - ctx->nincomplete, 2314 ctx->nincomplete, ctx->nold); 2315 2316 if (ctx->nnew == 0 && ctx->nold == 0) { 2317 debug_f("no new or deprecated keys from server"); 2318 goto out; 2319 } 2320 2321 /* Various reasons why we cannot proceed with the update */ 2322 if (ctx->complex_hostspec) { 2323 debug_f("CA/revocation marker, manual host list or wildcard " 2324 "host pattern found, skipping UserKnownHostsFile update"); 2325 goto out; 2326 } 2327 if (ctx->other_name_seen) { 2328 debug_f("host key found matching a different name/address, " 2329 "skipping UserKnownHostsFile update"); 2330 goto out; 2331 } 2332 /* 2333 * If removing keys, check whether they appear under different 2334 * names/addresses and refuse to proceed if they do. This avoids 2335 * cases such as hosts with multiple names becoming inconsistent 2336 * with regards to CheckHostIP entries. 2337 * XXX UpdateHostkeys=force to override this (and other) checks? 2338 */ 2339 if (ctx->nold != 0) { 2340 if (check_old_keys_othernames(ctx) != 0) 2341 goto out; /* error already logged */ 2342 if (ctx->old_key_seen) { 2343 debug_f("key(s) for %s%s%s exist under other names; " 2344 "skipping UserKnownHostsFile update", 2345 ctx->host_str, ctx->ip_str == NULL ? "" : ",", 2346 ctx->ip_str == NULL ? "" : ctx->ip_str); 2347 goto out; 2348 } 2349 } 2350 2351 if (ctx->nnew == 0) { 2352 /* 2353 * We have some keys to remove or fix matching for. 2354 * We can proceed to do this without requiring a fresh proof 2355 * from the server. 2356 */ 2357 update_known_hosts(ctx); 2358 goto out; 2359 } 2360 /* 2361 * We have received previously-unseen keys from the server. 2362 * Ask the server to confirm ownership of the private halves. 2363 */ 2364 debug3_f("asking server to prove ownership for %zu keys", ctx->nnew); 2365 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || 2366 (r = sshpkt_put_cstring(ssh, 2367 "hostkeys-prove-00@openssh.com")) != 0 || 2368 (r = sshpkt_put_u8(ssh, 1)) != 0) /* bool: want reply */ 2369 fatal_fr(r, "prepare hostkeys-prove"); 2370 if ((buf = sshbuf_new()) == NULL) 2371 fatal_f("sshbuf_new"); 2372 for (i = 0; i < ctx->nkeys; i++) { 2373 if (ctx->keys_match[i]) 2374 continue; 2375 sshbuf_reset(buf); 2376 if ((r = sshkey_putb(ctx->keys[i], buf)) != 0 || 2377 (r = sshpkt_put_stringb(ssh, buf)) != 0) 2378 fatal_fr(r, "assemble hostkeys-prove"); 2379 } 2380 if ((r = sshpkt_send(ssh)) != 0) 2381 fatal_fr(r, "send hostkeys-prove"); 2382 client_register_global_confirm( 2383 client_global_hostkeys_private_confirm, ctx); 2384 ctx = NULL; /* will be freed in callback */ 2385 2386 /* Success */ 2387 out: 2388 hostkeys_update_ctx_free(ctx); 2389 sshkey_free(key); 2390 sshbuf_free(buf); 2391 /* 2392 * NB. Return success for all cases. The server doesn't need to know 2393 * what the client does with its hosts file. 2394 */ 2395 return 1; 2396 } 2397 2398 static int 2399 client_input_global_request(int type, u_int32_t seq, struct ssh *ssh) 2400 { 2401 char *rtype; 2402 u_char want_reply; 2403 int r, success = 0; 2404 2405 if ((r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 || 2406 (r = sshpkt_get_u8(ssh, &want_reply)) != 0) 2407 goto out; 2408 debug("client_input_global_request: rtype %s want_reply %d", 2409 rtype, want_reply); 2410 if (strcmp(rtype, "hostkeys-00@openssh.com") == 0) 2411 success = client_input_hostkeys(ssh); 2412 if (want_reply) { 2413 if ((r = sshpkt_start(ssh, success ? SSH2_MSG_REQUEST_SUCCESS : 2414 SSH2_MSG_REQUEST_FAILURE)) != 0 || 2415 (r = sshpkt_send(ssh)) != 0 || 2416 (r = ssh_packet_write_wait(ssh)) != 0) 2417 goto out; 2418 } 2419 r = 0; 2420 out: 2421 free(rtype); 2422 return r; 2423 } 2424 2425 static void 2426 client_send_env(struct ssh *ssh, int id, const char *name, const char *val) 2427 { 2428 int r; 2429 2430 debug("channel %d: setting env %s = \"%s\"", id, name, val); 2431 channel_request_start(ssh, id, "env", 0); 2432 if ((r = sshpkt_put_cstring(ssh, name)) != 0 || 2433 (r = sshpkt_put_cstring(ssh, val)) != 0 || 2434 (r = sshpkt_send(ssh)) != 0) 2435 fatal_fr(r, "send setenv"); 2436 } 2437 2438 void 2439 client_session2_setup(struct ssh *ssh, int id, int want_tty, int want_subsystem, 2440 const char *term, struct termios *tiop, int in_fd, struct sshbuf *cmd, 2441 char **env) 2442 { 2443 int i, j, matched, len, r; 2444 char *name, *val; 2445 Channel *c = NULL; 2446 2447 debug2_f("id %d", id); 2448 2449 if ((c = channel_lookup(ssh, id)) == NULL) 2450 fatal_f("channel %d: unknown channel", id); 2451 2452 ssh_packet_set_interactive(ssh, want_tty, 2453 options.ip_qos_interactive, options.ip_qos_bulk); 2454 2455 if (want_tty) { 2456 struct winsize ws; 2457 2458 /* Store window size in the packet. */ 2459 if (ioctl(in_fd, TIOCGWINSZ, &ws) == -1) 2460 memset(&ws, 0, sizeof(ws)); 2461 2462 channel_request_start(ssh, id, "pty-req", 1); 2463 client_expect_confirm(ssh, id, "PTY allocation", CONFIRM_TTY); 2464 if ((r = sshpkt_put_cstring(ssh, term != NULL ? term : "")) 2465 != 0 || 2466 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_col)) != 0 || 2467 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_row)) != 0 || 2468 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_xpixel)) != 0 || 2469 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_ypixel)) != 0) 2470 fatal_fr(r, "build pty-req"); 2471 if (tiop == NULL) 2472 tiop = get_saved_tio(); 2473 ssh_tty_make_modes(ssh, -1, tiop); 2474 if ((r = sshpkt_send(ssh)) != 0) 2475 fatal_fr(r, "send pty-req"); 2476 /* XXX wait for reply */ 2477 c->client_tty = 1; 2478 } 2479 2480 /* Transfer any environment variables from client to server */ 2481 if (options.num_send_env != 0 && env != NULL) { 2482 debug("Sending environment."); 2483 for (i = 0; env[i] != NULL; i++) { 2484 /* Split */ 2485 name = xstrdup(env[i]); 2486 if ((val = strchr(name, '=')) == NULL) { 2487 free(name); 2488 continue; 2489 } 2490 *val++ = '\0'; 2491 2492 matched = 0; 2493 for (j = 0; j < options.num_send_env; j++) { 2494 if (match_pattern(name, options.send_env[j])) { 2495 matched = 1; 2496 break; 2497 } 2498 } 2499 if (!matched) { 2500 debug3("Ignored env %s", name); 2501 free(name); 2502 continue; 2503 } 2504 client_send_env(ssh, id, name, val); 2505 free(name); 2506 } 2507 } 2508 for (i = 0; i < options.num_setenv; i++) { 2509 /* Split */ 2510 name = xstrdup(options.setenv[i]); 2511 if ((val = strchr(name, '=')) == NULL) { 2512 free(name); 2513 continue; 2514 } 2515 *val++ = '\0'; 2516 client_send_env(ssh, id, name, val); 2517 free(name); 2518 } 2519 2520 len = sshbuf_len(cmd); 2521 if (len > 0) { 2522 if (len > 900) 2523 len = 900; 2524 if (want_subsystem) { 2525 debug("Sending subsystem: %.*s", 2526 len, (const u_char*)sshbuf_ptr(cmd)); 2527 channel_request_start(ssh, id, "subsystem", 1); 2528 client_expect_confirm(ssh, id, "subsystem", 2529 CONFIRM_CLOSE); 2530 } else { 2531 debug("Sending command: %.*s", 2532 len, (const u_char*)sshbuf_ptr(cmd)); 2533 channel_request_start(ssh, id, "exec", 1); 2534 client_expect_confirm(ssh, id, "exec", CONFIRM_CLOSE); 2535 } 2536 if ((r = sshpkt_put_stringb(ssh, cmd)) != 0 || 2537 (r = sshpkt_send(ssh)) != 0) 2538 fatal_fr(r, "send command"); 2539 } else { 2540 channel_request_start(ssh, id, "shell", 1); 2541 client_expect_confirm(ssh, id, "shell", CONFIRM_CLOSE); 2542 if ((r = sshpkt_send(ssh)) != 0) 2543 fatal_fr(r, "send shell"); 2544 } 2545 } 2546 2547 static void 2548 client_init_dispatch(struct ssh *ssh) 2549 { 2550 ssh_dispatch_init(ssh, &dispatch_protocol_error); 2551 2552 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); 2553 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_DATA, &channel_input_data); 2554 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); 2555 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); 2556 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open); 2557 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 2558 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 2559 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req); 2560 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); 2561 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm); 2562 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm); 2563 ssh_dispatch_set(ssh, SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request); 2564 2565 /* rekeying */ 2566 ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, &kex_input_kexinit); 2567 2568 /* global request reply messages */ 2569 ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply); 2570 ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply); 2571 } 2572 2573 void 2574 client_stop_mux(void) 2575 { 2576 if (options.control_path != NULL && muxserver_sock != -1) 2577 unlink(options.control_path); 2578 /* 2579 * If we are in persist mode, or don't have a shell, signal that we 2580 * should close when all active channels are closed. 2581 */ 2582 if (options.control_persist || no_shell_flag) { 2583 session_closed = 1; 2584 setproctitle("[stopped mux]"); 2585 } 2586 } 2587 2588 /* client specific fatal cleanup */ 2589 void 2590 cleanup_exit(int i) 2591 { 2592 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 2593 if (options.control_path != NULL && muxserver_sock != -1) 2594 unlink(options.control_path); 2595 ssh_kill_proxy_command(); 2596 _exit(i); 2597 } 2598