1 /* $OpenBSD: clientloop.c,v 1.358 2021/01/27 10:05:28 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 #include <signal.h> 80 #include <stdio.h> 81 #include <stdlib.h> 82 #include <string.h> 83 #include <stdarg.h> 84 #include <termios.h> 85 #include <pwd.h> 86 #include <unistd.h> 87 #include <limits.h> 88 89 #include "openbsd-compat/sys-queue.h" 90 #include "xmalloc.h" 91 #include "ssh.h" 92 #include "ssh2.h" 93 #include "packet.h" 94 #include "sshbuf.h" 95 #include "compat.h" 96 #include "channels.h" 97 #include "dispatch.h" 98 #include "sshkey.h" 99 #include "cipher.h" 100 #include "kex.h" 101 #include "myproposal.h" 102 #include "log.h" 103 #include "misc.h" 104 #include "readconf.h" 105 #include "clientloop.h" 106 #include "sshconnect.h" 107 #include "authfd.h" 108 #include "atomicio.h" 109 #include "sshpty.h" 110 #include "match.h" 111 #include "msg.h" 112 #include "ssherr.h" 113 #include "hostfile.h" 114 115 /* import options */ 116 extern Options options; 117 118 /* Flag indicating that stdin should be redirected from /dev/null. */ 119 extern int stdin_null_flag; 120 121 /* Flag indicating that no shell has been requested */ 122 extern int no_shell_flag; 123 124 /* Flag indicating that ssh should daemonise after authentication is complete */ 125 extern int fork_after_authentication_flag; 126 127 /* Control socket */ 128 extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */ 129 130 /* 131 * Name of the host we are connecting to. This is the name given on the 132 * command line, or the Hostname specified for the user-supplied name in a 133 * configuration file. 134 */ 135 extern char *host; 136 137 /* 138 * If this field is not NULL, the ForwardAgent socket is this path and different 139 * instead of SSH_AUTH_SOCK. 140 */ 141 extern char *forward_agent_sock_path; 142 143 /* 144 * Flag to indicate that we have received a window change signal which has 145 * not yet been processed. This will cause a message indicating the new 146 * window size to be sent to the server a little later. This is volatile 147 * because this is updated in a signal handler. 148 */ 149 static volatile sig_atomic_t received_window_change_signal = 0; 150 static volatile sig_atomic_t received_signal = 0; 151 152 /* Time when backgrounded control master using ControlPersist should exit */ 153 static time_t control_persist_exit_time = 0; 154 155 /* Common data for the client loop code. */ 156 volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */ 157 static int last_was_cr; /* Last character was a newline. */ 158 static int exit_status; /* Used to store the command exit status. */ 159 static struct sshbuf *stderr_buffer; /* Used for final exit message. */ 160 static int connection_in; /* Connection to server (input). */ 161 static int connection_out; /* Connection to server (output). */ 162 static int need_rekeying; /* Set to non-zero if rekeying is requested. */ 163 static int session_closed; /* In SSH2: login session closed. */ 164 static u_int x11_refuse_time; /* If >0, refuse x11 opens after this time. */ 165 static time_t server_alive_time; /* Time to do server_alive_check */ 166 167 static void client_init_dispatch(struct ssh *ssh); 168 int session_ident = -1; 169 170 /* Track escape per proto2 channel */ 171 struct escape_filter_ctx { 172 int escape_pending; 173 int escape_char; 174 }; 175 176 /* Context for channel confirmation replies */ 177 struct channel_reply_ctx { 178 const char *request_type; 179 int id; 180 enum confirm_action action; 181 }; 182 183 /* Global request success/failure callbacks */ 184 /* XXX move to struct ssh? */ 185 struct global_confirm { 186 TAILQ_ENTRY(global_confirm) entry; 187 global_confirm_cb *cb; 188 void *ctx; 189 int ref_count; 190 }; 191 TAILQ_HEAD(global_confirms, global_confirm); 192 static struct global_confirms global_confirms = 193 TAILQ_HEAD_INITIALIZER(global_confirms); 194 195 void ssh_process_session2_setup(int, int, int, struct sshbuf *); 196 197 /* 198 * Signal handler for the window change signal (SIGWINCH). This just sets a 199 * flag indicating that the window has changed. 200 */ 201 /*ARGSUSED */ 202 static void 203 window_change_handler(int sig) 204 { 205 received_window_change_signal = 1; 206 } 207 208 /* 209 * Signal handler for signals that cause the program to terminate. These 210 * signals must be trapped to restore terminal modes. 211 */ 212 /*ARGSUSED */ 213 static void 214 signal_handler(int sig) 215 { 216 received_signal = sig; 217 quit_pending = 1; 218 } 219 220 /* 221 * Sets control_persist_exit_time to the absolute time when the 222 * backgrounded control master should exit due to expiry of the 223 * ControlPersist timeout. Sets it to 0 if we are not a backgrounded 224 * control master process, or if there is no ControlPersist timeout. 225 */ 226 static void 227 set_control_persist_exit_time(struct ssh *ssh) 228 { 229 if (muxserver_sock == -1 || !options.control_persist 230 || options.control_persist_timeout == 0) { 231 /* not using a ControlPersist timeout */ 232 control_persist_exit_time = 0; 233 } else if (channel_still_open(ssh)) { 234 /* some client connections are still open */ 235 if (control_persist_exit_time > 0) 236 debug2_f("cancel scheduled exit"); 237 control_persist_exit_time = 0; 238 } else if (control_persist_exit_time <= 0) { 239 /* a client connection has recently closed */ 240 control_persist_exit_time = monotime() + 241 (time_t)options.control_persist_timeout; 242 debug2_f("schedule exit in %d seconds", 243 options.control_persist_timeout); 244 } 245 /* else we are already counting down to the timeout */ 246 } 247 248 #define SSH_X11_VALID_DISPLAY_CHARS ":/.-_" 249 static int 250 client_x11_display_valid(const char *display) 251 { 252 size_t i, dlen; 253 254 if (display == NULL) 255 return 0; 256 257 dlen = strlen(display); 258 for (i = 0; i < dlen; i++) { 259 if (!isalnum((u_char)display[i]) && 260 strchr(SSH_X11_VALID_DISPLAY_CHARS, display[i]) == NULL) { 261 debug("Invalid character '%c' in DISPLAY", display[i]); 262 return 0; 263 } 264 } 265 return 1; 266 } 267 268 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1" 269 #define X11_TIMEOUT_SLACK 60 270 int 271 client_x11_get_proto(struct ssh *ssh, const char *display, 272 const char *xauth_path, u_int trusted, u_int timeout, 273 char **_proto, char **_data) 274 { 275 char *cmd, line[512], xdisplay[512]; 276 char xauthfile[PATH_MAX], xauthdir[PATH_MAX]; 277 static char proto[512], data[512]; 278 FILE *f; 279 int got_data = 0, generated = 0, do_unlink = 0, r; 280 struct stat st; 281 u_int now, x11_timeout_real; 282 283 *_proto = proto; 284 *_data = data; 285 proto[0] = data[0] = xauthfile[0] = xauthdir[0] = '\0'; 286 287 if (!client_x11_display_valid(display)) { 288 if (display != NULL) 289 logit("DISPLAY \"%s\" invalid; disabling X11 forwarding", 290 display); 291 return -1; 292 } 293 if (xauth_path != NULL && stat(xauth_path, &st) == -1) { 294 debug("No xauth program."); 295 xauth_path = NULL; 296 } 297 298 if (xauth_path != NULL) { 299 /* 300 * Handle FamilyLocal case where $DISPLAY does 301 * not match an authorization entry. For this we 302 * just try "xauth list unix:displaynum.screennum". 303 * XXX: "localhost" match to determine FamilyLocal 304 * is not perfect. 305 */ 306 if (strncmp(display, "localhost:", 10) == 0) { 307 if ((r = snprintf(xdisplay, sizeof(xdisplay), "unix:%s", 308 display + 10)) < 0 || 309 (size_t)r >= sizeof(xdisplay)) { 310 error_f("display name too long"); 311 return -1; 312 } 313 display = xdisplay; 314 } 315 if (trusted == 0) { 316 /* 317 * Generate an untrusted X11 auth cookie. 318 * 319 * The authentication cookie should briefly outlive 320 * ssh's willingness to forward X11 connections to 321 * avoid nasty fail-open behaviour in the X server. 322 */ 323 mktemp_proto(xauthdir, sizeof(xauthdir)); 324 if (mkdtemp(xauthdir) == NULL) { 325 error_f("mkdtemp: %s", strerror(errno)); 326 return -1; 327 } 328 do_unlink = 1; 329 if ((r = snprintf(xauthfile, sizeof(xauthfile), 330 "%s/xauthfile", xauthdir)) < 0 || 331 (size_t)r >= sizeof(xauthfile)) { 332 error_f("xauthfile path too long"); 333 rmdir(xauthdir); 334 return -1; 335 } 336 337 if (timeout == 0) { 338 /* auth doesn't time out */ 339 xasprintf(&cmd, "%s -f %s generate %s %s " 340 "untrusted 2>%s", 341 xauth_path, xauthfile, display, 342 SSH_X11_PROTO, _PATH_DEVNULL); 343 } else { 344 /* Add some slack to requested expiry */ 345 if (timeout < UINT_MAX - X11_TIMEOUT_SLACK) 346 x11_timeout_real = timeout + 347 X11_TIMEOUT_SLACK; 348 else { 349 /* Don't overflow on long timeouts */ 350 x11_timeout_real = UINT_MAX; 351 } 352 xasprintf(&cmd, "%s -f %s generate %s %s " 353 "untrusted timeout %u 2>%s", 354 xauth_path, xauthfile, display, 355 SSH_X11_PROTO, x11_timeout_real, 356 _PATH_DEVNULL); 357 } 358 debug2_f("xauth command: %s", cmd); 359 360 if (timeout != 0 && x11_refuse_time == 0) { 361 now = monotime() + 1; 362 if (UINT_MAX - timeout < now) 363 x11_refuse_time = UINT_MAX; 364 else 365 x11_refuse_time = now + timeout; 366 channel_set_x11_refuse_time(ssh, 367 x11_refuse_time); 368 } 369 if (system(cmd) == 0) 370 generated = 1; 371 free(cmd); 372 } 373 374 /* 375 * When in untrusted mode, we read the cookie only if it was 376 * successfully generated as an untrusted one in the step 377 * above. 378 */ 379 if (trusted || generated) { 380 xasprintf(&cmd, 381 "%s %s%s list %s 2>" _PATH_DEVNULL, 382 xauth_path, 383 generated ? "-f " : "" , 384 generated ? xauthfile : "", 385 display); 386 debug2("x11_get_proto: %s", cmd); 387 f = popen(cmd, "r"); 388 if (f && fgets(line, sizeof(line), f) && 389 sscanf(line, "%*s %511s %511s", proto, data) == 2) 390 got_data = 1; 391 if (f) 392 pclose(f); 393 free(cmd); 394 } 395 } 396 397 if (do_unlink) { 398 unlink(xauthfile); 399 rmdir(xauthdir); 400 } 401 402 /* Don't fall back to fake X11 data for untrusted forwarding */ 403 if (!trusted && !got_data) { 404 error("Warning: untrusted X11 forwarding setup failed: " 405 "xauth key data not generated"); 406 return -1; 407 } 408 409 /* 410 * If we didn't get authentication data, just make up some 411 * data. The forwarding code will check the validity of the 412 * response anyway, and substitute this data. The X11 413 * server, however, will ignore this fake data and use 414 * whatever authentication mechanisms it was using otherwise 415 * for the local connection. 416 */ 417 if (!got_data) { 418 u_int8_t rnd[16]; 419 u_int i; 420 421 logit("Warning: No xauth data; " 422 "using fake authentication data for X11 forwarding."); 423 strlcpy(proto, SSH_X11_PROTO, sizeof proto); 424 arc4random_buf(rnd, sizeof(rnd)); 425 for (i = 0; i < sizeof(rnd); i++) { 426 snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", 427 rnd[i]); 428 } 429 } 430 431 return 0; 432 } 433 434 /* 435 * Checks if the client window has changed, and sends a packet about it to 436 * the server if so. The actual change is detected elsewhere (by a software 437 * interrupt on Unix); this just checks the flag and sends a message if 438 * appropriate. 439 */ 440 441 static void 442 client_check_window_change(struct ssh *ssh) 443 { 444 if (!received_window_change_signal) 445 return; 446 received_window_change_signal = 0; 447 debug2_f("changed"); 448 channel_send_window_changes(ssh); 449 } 450 451 static int 452 client_global_request_reply(int type, u_int32_t seq, struct ssh *ssh) 453 { 454 struct global_confirm *gc; 455 456 if ((gc = TAILQ_FIRST(&global_confirms)) == NULL) 457 return 0; 458 if (gc->cb != NULL) 459 gc->cb(ssh, type, seq, gc->ctx); 460 if (--gc->ref_count <= 0) { 461 TAILQ_REMOVE(&global_confirms, gc, entry); 462 freezero(gc, sizeof(*gc)); 463 } 464 465 ssh_packet_set_alive_timeouts(ssh, 0); 466 return 0; 467 } 468 469 static void 470 schedule_server_alive_check(void) 471 { 472 if (options.server_alive_interval > 0) 473 server_alive_time = monotime() + options.server_alive_interval; 474 } 475 476 static void 477 server_alive_check(struct ssh *ssh) 478 { 479 int r; 480 481 if (ssh_packet_inc_alive_timeouts(ssh) > options.server_alive_count_max) { 482 logit("Timeout, server %s not responding.", host); 483 cleanup_exit(255); 484 } 485 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || 486 (r = sshpkt_put_cstring(ssh, "keepalive@openssh.com")) != 0 || 487 (r = sshpkt_put_u8(ssh, 1)) != 0 || /* boolean: want reply */ 488 (r = sshpkt_send(ssh)) != 0) 489 fatal_fr(r, "send packet"); 490 /* Insert an empty placeholder to maintain ordering */ 491 client_register_global_confirm(NULL, NULL); 492 schedule_server_alive_check(); 493 } 494 495 /* 496 * Waits until the client can do something (some data becomes available on 497 * one of the file descriptors). 498 */ 499 static void 500 client_wait_until_can_do_something(struct ssh *ssh, 501 fd_set **readsetp, fd_set **writesetp, 502 int *maxfdp, u_int *nallocp, int rekeying) 503 { 504 struct timeval tv, *tvp; 505 int timeout_secs; 506 time_t minwait_secs = 0, now = monotime(); 507 int r, ret; 508 509 /* Add any selections by the channel mechanism. */ 510 channel_prepare_select(ssh, readsetp, writesetp, maxfdp, 511 nallocp, &minwait_secs); 512 513 /* channel_prepare_select could have closed the last channel */ 514 if (session_closed && !channel_still_open(ssh) && 515 !ssh_packet_have_data_to_write(ssh)) { 516 /* clear mask since we did not call select() */ 517 memset(*readsetp, 0, *nallocp); 518 memset(*writesetp, 0, *nallocp); 519 return; 520 } 521 522 FD_SET(connection_in, *readsetp); 523 524 /* Select server connection if have data to write to the server. */ 525 if (ssh_packet_have_data_to_write(ssh)) 526 FD_SET(connection_out, *writesetp); 527 528 /* 529 * Wait for something to happen. This will suspend the process until 530 * some selected descriptor can be read, written, or has some other 531 * event pending, or a timeout expires. 532 */ 533 534 timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */ 535 if (options.server_alive_interval > 0) 536 timeout_secs = MAXIMUM(server_alive_time - now, 0); 537 if (options.rekey_interval > 0 && !rekeying) 538 timeout_secs = MINIMUM(timeout_secs, 539 ssh_packet_get_rekey_timeout(ssh)); 540 set_control_persist_exit_time(ssh); 541 if (control_persist_exit_time > 0) { 542 timeout_secs = MINIMUM(timeout_secs, 543 control_persist_exit_time - now); 544 if (timeout_secs < 0) 545 timeout_secs = 0; 546 } 547 if (minwait_secs != 0) 548 timeout_secs = MINIMUM(timeout_secs, (int)minwait_secs); 549 if (timeout_secs == INT_MAX) 550 tvp = NULL; 551 else { 552 tv.tv_sec = timeout_secs; 553 tv.tv_usec = 0; 554 tvp = &tv; 555 } 556 557 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); 558 if (ret == -1) { 559 /* 560 * We have to clear the select masks, because we return. 561 * We have to return, because the mainloop checks for the flags 562 * set by the signal handlers. 563 */ 564 memset(*readsetp, 0, *nallocp); 565 memset(*writesetp, 0, *nallocp); 566 if (errno == EINTR) 567 return; 568 /* Note: we might still have data in the buffers. */ 569 if ((r = sshbuf_putf(stderr_buffer, 570 "select: %s\r\n", strerror(errno))) != 0) 571 fatal_fr(r, "sshbuf_putf"); 572 quit_pending = 1; 573 } else if (options.server_alive_interval > 0 && !FD_ISSET(connection_in, 574 *readsetp) && monotime() >= server_alive_time) 575 /* 576 * ServerAlive check is needed. We can't rely on the select 577 * timing out since traffic on the client side such as port 578 * forwards can keep waking it up. 579 */ 580 server_alive_check(ssh); 581 } 582 583 static void 584 client_suspend_self(struct sshbuf *bin, struct sshbuf *bout, struct sshbuf *berr) 585 { 586 /* Flush stdout and stderr buffers. */ 587 if (sshbuf_len(bout) > 0) 588 atomicio(vwrite, fileno(stdout), sshbuf_mutable_ptr(bout), 589 sshbuf_len(bout)); 590 if (sshbuf_len(berr) > 0) 591 atomicio(vwrite, fileno(stderr), sshbuf_mutable_ptr(berr), 592 sshbuf_len(berr)); 593 594 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 595 596 sshbuf_reset(bin); 597 sshbuf_reset(bout); 598 sshbuf_reset(berr); 599 600 /* Send the suspend signal to the program itself. */ 601 kill(getpid(), SIGTSTP); 602 603 /* Reset window sizes in case they have changed */ 604 received_window_change_signal = 1; 605 606 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 607 } 608 609 static void 610 client_process_net_input(struct ssh *ssh, fd_set *readset) 611 { 612 char buf[SSH_IOBUFSZ]; 613 int r, len; 614 615 /* 616 * Read input from the server, and add any such data to the buffer of 617 * the packet subsystem. 618 */ 619 if (FD_ISSET(connection_in, readset)) { 620 schedule_server_alive_check(); 621 /* Read as much as possible. */ 622 len = read(connection_in, buf, sizeof(buf)); 623 if (len == 0) { 624 /* 625 * Received EOF. The remote host has closed the 626 * connection. 627 */ 628 if ((r = sshbuf_putf(stderr_buffer, 629 "Connection to %.300s closed by remote host.\r\n", 630 host)) != 0) 631 fatal_fr(r, "sshbuf_putf"); 632 quit_pending = 1; 633 return; 634 } 635 /* 636 * There is a kernel bug on Solaris that causes select to 637 * sometimes wake up even though there is no data available. 638 */ 639 if (len == -1 && 640 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)) 641 len = 0; 642 643 if (len == -1) { 644 /* 645 * An error has encountered. Perhaps there is a 646 * network problem. 647 */ 648 if ((r = sshbuf_putf(stderr_buffer, 649 "Read from remote host %.300s: %.100s\r\n", 650 host, strerror(errno))) != 0) 651 fatal_fr(r, "sshbuf_putf"); 652 quit_pending = 1; 653 return; 654 } 655 ssh_packet_process_incoming(ssh, buf, len); 656 } 657 } 658 659 static void 660 client_status_confirm(struct ssh *ssh, int type, Channel *c, void *ctx) 661 { 662 struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx; 663 char errmsg[256]; 664 int r, tochan; 665 666 /* 667 * If a TTY was explicitly requested, then a failure to allocate 668 * one is fatal. 669 */ 670 if (cr->action == CONFIRM_TTY && 671 (options.request_tty == REQUEST_TTY_FORCE || 672 options.request_tty == REQUEST_TTY_YES)) 673 cr->action = CONFIRM_CLOSE; 674 675 /* XXX suppress on mux _client_ quietmode */ 676 tochan = options.log_level >= SYSLOG_LEVEL_ERROR && 677 c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE; 678 679 if (type == SSH2_MSG_CHANNEL_SUCCESS) { 680 debug2("%s request accepted on channel %d", 681 cr->request_type, c->self); 682 } else if (type == SSH2_MSG_CHANNEL_FAILURE) { 683 if (tochan) { 684 snprintf(errmsg, sizeof(errmsg), 685 "%s request failed\r\n", cr->request_type); 686 } else { 687 snprintf(errmsg, sizeof(errmsg), 688 "%s request failed on channel %d", 689 cr->request_type, c->self); 690 } 691 /* If error occurred on primary session channel, then exit */ 692 if (cr->action == CONFIRM_CLOSE && c->self == session_ident) 693 fatal("%s", errmsg); 694 /* 695 * If error occurred on mux client, append to 696 * their stderr. 697 */ 698 if (tochan) { 699 if ((r = sshbuf_put(c->extended, errmsg, 700 strlen(errmsg))) != 0) 701 fatal_fr(r, "sshbuf_put"); 702 } else 703 error("%s", errmsg); 704 if (cr->action == CONFIRM_TTY) { 705 /* 706 * If a TTY allocation error occurred, then arrange 707 * for the correct TTY to leave raw mode. 708 */ 709 if (c->self == session_ident) 710 leave_raw_mode(0); 711 else 712 mux_tty_alloc_failed(ssh, c); 713 } else if (cr->action == CONFIRM_CLOSE) { 714 chan_read_failed(ssh, c); 715 chan_write_failed(ssh, c); 716 } 717 } 718 free(cr); 719 } 720 721 static void 722 client_abandon_status_confirm(struct ssh *ssh, Channel *c, void *ctx) 723 { 724 free(ctx); 725 } 726 727 void 728 client_expect_confirm(struct ssh *ssh, int id, const char *request, 729 enum confirm_action action) 730 { 731 struct channel_reply_ctx *cr = xcalloc(1, sizeof(*cr)); 732 733 cr->request_type = request; 734 cr->action = action; 735 736 channel_register_status_confirm(ssh, id, client_status_confirm, 737 client_abandon_status_confirm, cr); 738 } 739 740 void 741 client_register_global_confirm(global_confirm_cb *cb, void *ctx) 742 { 743 struct global_confirm *gc, *last_gc; 744 745 /* Coalesce identical callbacks */ 746 last_gc = TAILQ_LAST(&global_confirms, global_confirms); 747 if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) { 748 if (++last_gc->ref_count >= INT_MAX) 749 fatal_f("last_gc->ref_count = %d", 750 last_gc->ref_count); 751 return; 752 } 753 754 gc = xcalloc(1, sizeof(*gc)); 755 gc->cb = cb; 756 gc->ctx = ctx; 757 gc->ref_count = 1; 758 TAILQ_INSERT_TAIL(&global_confirms, gc, entry); 759 } 760 761 static void 762 process_cmdline(struct ssh *ssh) 763 { 764 void (*handler)(int); 765 char *s, *cmd; 766 int ok, delete = 0, local = 0, remote = 0, dynamic = 0; 767 struct Forward fwd; 768 769 memset(&fwd, 0, sizeof(fwd)); 770 771 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 772 handler = ssh_signal(SIGINT, SIG_IGN); 773 cmd = s = read_passphrase("\r\nssh> ", RP_ECHO); 774 if (s == NULL) 775 goto out; 776 while (isspace((u_char)*s)) 777 s++; 778 if (*s == '-') 779 s++; /* Skip cmdline '-', if any */ 780 if (*s == '\0') 781 goto out; 782 783 if (*s == 'h' || *s == 'H' || *s == '?') { 784 logit("Commands:"); 785 logit(" -L[bind_address:]port:host:hostport " 786 "Request local forward"); 787 logit(" -R[bind_address:]port:host:hostport " 788 "Request remote forward"); 789 logit(" -D[bind_address:]port " 790 "Request dynamic forward"); 791 logit(" -KL[bind_address:]port " 792 "Cancel local forward"); 793 logit(" -KR[bind_address:]port " 794 "Cancel remote forward"); 795 logit(" -KD[bind_address:]port " 796 "Cancel dynamic forward"); 797 if (!options.permit_local_command) 798 goto out; 799 logit(" !args " 800 "Execute local command"); 801 goto out; 802 } 803 804 if (*s == '!' && options.permit_local_command) { 805 s++; 806 ssh_local_cmd(s); 807 goto out; 808 } 809 810 if (*s == 'K') { 811 delete = 1; 812 s++; 813 } 814 if (*s == 'L') 815 local = 1; 816 else if (*s == 'R') 817 remote = 1; 818 else if (*s == 'D') 819 dynamic = 1; 820 else { 821 logit("Invalid command."); 822 goto out; 823 } 824 825 while (isspace((u_char)*++s)) 826 ; 827 828 /* XXX update list of forwards in options */ 829 if (delete) { 830 /* We pass 1 for dynamicfwd to restrict to 1 or 2 fields. */ 831 if (!parse_forward(&fwd, s, 1, 0)) { 832 logit("Bad forwarding close specification."); 833 goto out; 834 } 835 if (remote) 836 ok = channel_request_rforward_cancel(ssh, &fwd) == 0; 837 else if (dynamic) 838 ok = channel_cancel_lport_listener(ssh, &fwd, 839 0, &options.fwd_opts) > 0; 840 else 841 ok = channel_cancel_lport_listener(ssh, &fwd, 842 CHANNEL_CANCEL_PORT_STATIC, 843 &options.fwd_opts) > 0; 844 if (!ok) { 845 logit("Unknown port forwarding."); 846 goto out; 847 } 848 logit("Canceled forwarding."); 849 } else { 850 if (!parse_forward(&fwd, s, dynamic, remote)) { 851 logit("Bad forwarding specification."); 852 goto out; 853 } 854 if (local || dynamic) { 855 if (!channel_setup_local_fwd_listener(ssh, &fwd, 856 &options.fwd_opts)) { 857 logit("Port forwarding failed."); 858 goto out; 859 } 860 } else { 861 if (channel_request_remote_forwarding(ssh, &fwd) < 0) { 862 logit("Port forwarding failed."); 863 goto out; 864 } 865 } 866 logit("Forwarding port."); 867 } 868 869 out: 870 ssh_signal(SIGINT, handler); 871 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 872 free(cmd); 873 free(fwd.listen_host); 874 free(fwd.listen_path); 875 free(fwd.connect_host); 876 free(fwd.connect_path); 877 } 878 879 /* reasons to suppress output of an escape command in help output */ 880 #define SUPPRESS_NEVER 0 /* never suppress, always show */ 881 #define SUPPRESS_MUXCLIENT 1 /* don't show in mux client sessions */ 882 #define SUPPRESS_MUXMASTER 2 /* don't show in mux master sessions */ 883 #define SUPPRESS_SYSLOG 4 /* don't show when logging to syslog */ 884 struct escape_help_text { 885 const char *cmd; 886 const char *text; 887 unsigned int flags; 888 }; 889 static struct escape_help_text esc_txt[] = { 890 {".", "terminate session", SUPPRESS_MUXMASTER}, 891 {".", "terminate connection (and any multiplexed sessions)", 892 SUPPRESS_MUXCLIENT}, 893 {"B", "send a BREAK to the remote system", SUPPRESS_NEVER}, 894 {"C", "open a command line", SUPPRESS_MUXCLIENT}, 895 {"R", "request rekey", SUPPRESS_NEVER}, 896 {"V/v", "decrease/increase verbosity (LogLevel)", SUPPRESS_MUXCLIENT}, 897 {"^Z", "suspend ssh", SUPPRESS_MUXCLIENT}, 898 {"#", "list forwarded connections", SUPPRESS_NEVER}, 899 {"&", "background ssh (when waiting for connections to terminate)", 900 SUPPRESS_MUXCLIENT}, 901 {"?", "this message", SUPPRESS_NEVER}, 902 }; 903 904 static void 905 print_escape_help(struct sshbuf *b, int escape_char, int mux_client, 906 int using_stderr) 907 { 908 unsigned int i, suppress_flags; 909 int r; 910 911 if ((r = sshbuf_putf(b, 912 "%c?\r\nSupported escape sequences:\r\n", escape_char)) != 0) 913 fatal_fr(r, "sshbuf_putf"); 914 915 suppress_flags = 916 (mux_client ? SUPPRESS_MUXCLIENT : 0) | 917 (mux_client ? 0 : SUPPRESS_MUXMASTER) | 918 (using_stderr ? 0 : SUPPRESS_SYSLOG); 919 920 for (i = 0; i < sizeof(esc_txt)/sizeof(esc_txt[0]); i++) { 921 if (esc_txt[i].flags & suppress_flags) 922 continue; 923 if ((r = sshbuf_putf(b, " %c%-3s - %s\r\n", 924 escape_char, esc_txt[i].cmd, esc_txt[i].text)) != 0) 925 fatal_fr(r, "sshbuf_putf"); 926 } 927 928 if ((r = sshbuf_putf(b, 929 " %c%c - send the escape character by typing it twice\r\n" 930 "(Note that escapes are only recognized immediately after " 931 "newline.)\r\n", escape_char, escape_char)) != 0) 932 fatal_fr(r, "sshbuf_putf"); 933 } 934 935 /* 936 * Process the characters one by one. 937 */ 938 static int 939 process_escapes(struct ssh *ssh, Channel *c, 940 struct sshbuf *bin, struct sshbuf *bout, struct sshbuf *berr, 941 char *buf, int len) 942 { 943 pid_t pid; 944 int r, bytes = 0; 945 u_int i; 946 u_char ch; 947 char *s; 948 struct escape_filter_ctx *efc = c->filter_ctx == NULL ? 949 NULL : (struct escape_filter_ctx *)c->filter_ctx; 950 951 if (c->filter_ctx == NULL) 952 return 0; 953 954 if (len <= 0) 955 return (0); 956 957 for (i = 0; i < (u_int)len; i++) { 958 /* Get one character at a time. */ 959 ch = buf[i]; 960 961 if (efc->escape_pending) { 962 /* We have previously seen an escape character. */ 963 /* Clear the flag now. */ 964 efc->escape_pending = 0; 965 966 /* Process the escaped character. */ 967 switch (ch) { 968 case '.': 969 /* Terminate the connection. */ 970 if ((r = sshbuf_putf(berr, "%c.\r\n", 971 efc->escape_char)) != 0) 972 fatal_fr(r, "sshbuf_putf"); 973 if (c && c->ctl_chan != -1) { 974 chan_read_failed(ssh, c); 975 chan_write_failed(ssh, c); 976 if (c->detach_user) { 977 c->detach_user(ssh, 978 c->self, NULL); 979 } 980 c->type = SSH_CHANNEL_ABANDONED; 981 sshbuf_reset(c->input); 982 chan_ibuf_empty(ssh, c); 983 return 0; 984 } else 985 quit_pending = 1; 986 return -1; 987 988 case 'Z' - 64: 989 /* XXX support this for mux clients */ 990 if (c && c->ctl_chan != -1) { 991 char b[16]; 992 noescape: 993 if (ch == 'Z' - 64) 994 snprintf(b, sizeof b, "^Z"); 995 else 996 snprintf(b, sizeof b, "%c", ch); 997 if ((r = sshbuf_putf(berr, 998 "%c%s escape not available to " 999 "multiplexed sessions\r\n", 1000 efc->escape_char, b)) != 0) 1001 fatal_fr(r, "sshbuf_putf"); 1002 continue; 1003 } 1004 /* Suspend the program. Inform the user */ 1005 if ((r = sshbuf_putf(berr, 1006 "%c^Z [suspend ssh]\r\n", 1007 efc->escape_char)) != 0) 1008 fatal_fr(r, "sshbuf_putf"); 1009 1010 /* Restore terminal modes and suspend. */ 1011 client_suspend_self(bin, bout, berr); 1012 1013 /* We have been continued. */ 1014 continue; 1015 1016 case 'B': 1017 if ((r = sshbuf_putf(berr, 1018 "%cB\r\n", efc->escape_char)) != 0) 1019 fatal_fr(r, "sshbuf_putf"); 1020 channel_request_start(ssh, c->self, "break", 0); 1021 if ((r = sshpkt_put_u32(ssh, 1000)) != 0 || 1022 (r = sshpkt_send(ssh)) != 0) 1023 fatal_fr(r, "send packet"); 1024 continue; 1025 1026 case 'R': 1027 if (ssh->compat & SSH_BUG_NOREKEY) 1028 logit("Server does not " 1029 "support re-keying"); 1030 else 1031 need_rekeying = 1; 1032 continue; 1033 1034 case 'V': 1035 /* FALLTHROUGH */ 1036 case 'v': 1037 if (c && c->ctl_chan != -1) 1038 goto noescape; 1039 if (!log_is_on_stderr()) { 1040 if ((r = sshbuf_putf(berr, 1041 "%c%c [Logging to syslog]\r\n", 1042 efc->escape_char, ch)) != 0) 1043 fatal_fr(r, "sshbuf_putf"); 1044 continue; 1045 } 1046 if (ch == 'V' && options.log_level > 1047 SYSLOG_LEVEL_QUIET) 1048 log_change_level(--options.log_level); 1049 if (ch == 'v' && options.log_level < 1050 SYSLOG_LEVEL_DEBUG3) 1051 log_change_level(++options.log_level); 1052 if ((r = sshbuf_putf(berr, 1053 "%c%c [LogLevel %s]\r\n", 1054 efc->escape_char, ch, 1055 log_level_name(options.log_level))) != 0) 1056 fatal_fr(r, "sshbuf_putf"); 1057 continue; 1058 1059 case '&': 1060 if (c && c->ctl_chan != -1) 1061 goto noescape; 1062 /* 1063 * Detach the program (continue to serve 1064 * connections, but put in background and no 1065 * more new connections). 1066 */ 1067 /* Restore tty modes. */ 1068 leave_raw_mode( 1069 options.request_tty == REQUEST_TTY_FORCE); 1070 1071 /* Stop listening for new connections. */ 1072 channel_stop_listening(ssh); 1073 1074 if ((r = sshbuf_putf(berr, "%c& " 1075 "[backgrounded]\n", efc->escape_char)) != 0) 1076 fatal_fr(r, "sshbuf_putf"); 1077 1078 /* Fork into background. */ 1079 pid = fork(); 1080 if (pid == -1) { 1081 error("fork: %.100s", strerror(errno)); 1082 continue; 1083 } 1084 if (pid != 0) { /* This is the parent. */ 1085 /* The parent just exits. */ 1086 exit(0); 1087 } 1088 /* The child continues serving connections. */ 1089 /* fake EOF on stdin */ 1090 if ((r = sshbuf_put_u8(bin, 4)) != 0) 1091 fatal_fr(r, "sshbuf_put_u8"); 1092 return -1; 1093 case '?': 1094 print_escape_help(berr, efc->escape_char, 1095 (c && c->ctl_chan != -1), 1096 log_is_on_stderr()); 1097 continue; 1098 1099 case '#': 1100 if ((r = sshbuf_putf(berr, "%c#\r\n", 1101 efc->escape_char)) != 0) 1102 fatal_fr(r, "sshbuf_putf"); 1103 s = channel_open_message(ssh); 1104 if ((r = sshbuf_put(berr, s, strlen(s))) != 0) 1105 fatal_fr(r, "sshbuf_put"); 1106 free(s); 1107 continue; 1108 1109 case 'C': 1110 if (c && c->ctl_chan != -1) 1111 goto noescape; 1112 process_cmdline(ssh); 1113 continue; 1114 1115 default: 1116 if (ch != efc->escape_char) { 1117 if ((r = sshbuf_put_u8(bin, 1118 efc->escape_char)) != 0) 1119 fatal_fr(r, "sshbuf_put_u8"); 1120 bytes++; 1121 } 1122 /* Escaped characters fall through here */ 1123 break; 1124 } 1125 } else { 1126 /* 1127 * The previous character was not an escape char. 1128 * Check if this is an escape. 1129 */ 1130 if (last_was_cr && ch == efc->escape_char) { 1131 /* 1132 * It is. Set the flag and continue to 1133 * next character. 1134 */ 1135 efc->escape_pending = 1; 1136 continue; 1137 } 1138 } 1139 1140 /* 1141 * Normal character. Record whether it was a newline, 1142 * and append it to the buffer. 1143 */ 1144 last_was_cr = (ch == '\r' || ch == '\n'); 1145 if ((r = sshbuf_put_u8(bin, ch)) != 0) 1146 fatal_fr(r, "sshbuf_put_u8"); 1147 bytes++; 1148 } 1149 return bytes; 1150 } 1151 1152 /* 1153 * Get packets from the connection input buffer, and process them as long as 1154 * there are packets available. 1155 * 1156 * Any unknown packets received during the actual 1157 * session cause the session to terminate. This is 1158 * intended to make debugging easier since no 1159 * confirmations are sent. Any compatible protocol 1160 * extensions must be negotiated during the 1161 * preparatory phase. 1162 */ 1163 1164 static void 1165 client_process_buffered_input_packets(struct ssh *ssh) 1166 { 1167 ssh_dispatch_run_fatal(ssh, DISPATCH_NONBLOCK, &quit_pending); 1168 } 1169 1170 /* scan buf[] for '~' before sending data to the peer */ 1171 1172 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */ 1173 void * 1174 client_new_escape_filter_ctx(int escape_char) 1175 { 1176 struct escape_filter_ctx *ret; 1177 1178 ret = xcalloc(1, sizeof(*ret)); 1179 ret->escape_pending = 0; 1180 ret->escape_char = escape_char; 1181 return (void *)ret; 1182 } 1183 1184 /* Free the escape filter context on channel free */ 1185 void 1186 client_filter_cleanup(struct ssh *ssh, int cid, void *ctx) 1187 { 1188 free(ctx); 1189 } 1190 1191 int 1192 client_simple_escape_filter(struct ssh *ssh, Channel *c, char *buf, int len) 1193 { 1194 if (c->extended_usage != CHAN_EXTENDED_WRITE) 1195 return 0; 1196 1197 return process_escapes(ssh, c, c->input, c->output, c->extended, 1198 buf, len); 1199 } 1200 1201 static void 1202 client_channel_closed(struct ssh *ssh, int id, void *arg) 1203 { 1204 channel_cancel_cleanup(ssh, id); 1205 session_closed = 1; 1206 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1207 } 1208 1209 /* 1210 * Implements the interactive session with the server. This is called after 1211 * the user has been authenticated, and a command has been started on the 1212 * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character 1213 * used as an escape character for terminating or suspending the session. 1214 */ 1215 int 1216 client_loop(struct ssh *ssh, int have_pty, int escape_char_arg, 1217 int ssh2_chan_id) 1218 { 1219 fd_set *readset = NULL, *writeset = NULL; 1220 double start_time, total_time; 1221 int r, max_fd = 0, max_fd2 = 0, len; 1222 u_int64_t ibytes, obytes; 1223 u_int nalloc = 0; 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 full"); 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 fork_after_authentication_flag) { 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 max_fd = MAXIMUM(connection_in, connection_out); 1266 1267 quit_pending = 0; 1268 1269 /* Initialize buffer. */ 1270 if ((stderr_buffer = sshbuf_new()) == NULL) 1271 fatal_f("sshbuf_new failed"); 1272 1273 client_init_dispatch(ssh); 1274 1275 /* 1276 * Set signal handlers, (e.g. to restore non-blocking mode) 1277 * but don't overwrite SIG_IGN, matches behaviour from rsh(1) 1278 */ 1279 if (ssh_signal(SIGHUP, SIG_IGN) != SIG_IGN) 1280 ssh_signal(SIGHUP, signal_handler); 1281 if (ssh_signal(SIGINT, SIG_IGN) != SIG_IGN) 1282 ssh_signal(SIGINT, signal_handler); 1283 if (ssh_signal(SIGQUIT, SIG_IGN) != SIG_IGN) 1284 ssh_signal(SIGQUIT, signal_handler); 1285 if (ssh_signal(SIGTERM, SIG_IGN) != SIG_IGN) 1286 ssh_signal(SIGTERM, signal_handler); 1287 ssh_signal(SIGWINCH, window_change_handler); 1288 1289 if (have_pty) 1290 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1291 1292 session_ident = ssh2_chan_id; 1293 if (session_ident != -1) { 1294 if (escape_char_arg != SSH_ESCAPECHAR_NONE) { 1295 channel_register_filter(ssh, session_ident, 1296 client_simple_escape_filter, NULL, 1297 client_filter_cleanup, 1298 client_new_escape_filter_ctx( 1299 escape_char_arg)); 1300 } 1301 channel_register_cleanup(ssh, session_ident, 1302 client_channel_closed, 0); 1303 } 1304 1305 schedule_server_alive_check(); 1306 1307 /* Main loop of the client for the interactive session mode. */ 1308 while (!quit_pending) { 1309 1310 /* Process buffered packets sent by the server. */ 1311 client_process_buffered_input_packets(ssh); 1312 1313 if (session_closed && !channel_still_open(ssh)) 1314 break; 1315 1316 if (ssh_packet_is_rekeying(ssh)) { 1317 debug("rekeying in progress"); 1318 } else if (need_rekeying) { 1319 /* manual rekey request */ 1320 debug("need rekeying"); 1321 if ((r = kex_start_rekex(ssh)) != 0) 1322 fatal_fr(r, "kex_start_rekex"); 1323 need_rekeying = 0; 1324 } else { 1325 /* 1326 * Make packets from buffered channel data, and 1327 * enqueue them for sending to the server. 1328 */ 1329 if (ssh_packet_not_very_much_data_to_write(ssh)) 1330 channel_output_poll(ssh); 1331 1332 /* 1333 * Check if the window size has changed, and buffer a 1334 * message about it to the server if so. 1335 */ 1336 client_check_window_change(ssh); 1337 1338 if (quit_pending) 1339 break; 1340 } 1341 /* 1342 * Wait until we have something to do (something becomes 1343 * available on one of the descriptors). 1344 */ 1345 max_fd2 = max_fd; 1346 client_wait_until_can_do_something(ssh, &readset, &writeset, 1347 &max_fd2, &nalloc, ssh_packet_is_rekeying(ssh)); 1348 1349 if (quit_pending) 1350 break; 1351 1352 /* Do channel operations unless rekeying in progress. */ 1353 if (!ssh_packet_is_rekeying(ssh)) 1354 channel_after_select(ssh, readset, writeset); 1355 1356 /* Buffer input from the connection. */ 1357 client_process_net_input(ssh, readset); 1358 1359 if (quit_pending) 1360 break; 1361 1362 /* 1363 * Send as much buffered packet data as possible to the 1364 * sender. 1365 */ 1366 if (FD_ISSET(connection_out, writeset)) { 1367 if ((r = ssh_packet_write_poll(ssh)) != 0) { 1368 sshpkt_fatal(ssh, r, 1369 "%s: ssh_packet_write_poll", __func__); 1370 } 1371 } 1372 1373 /* 1374 * If we are a backgrounded control master, and the 1375 * timeout has expired without any active client 1376 * connections, then quit. 1377 */ 1378 if (control_persist_exit_time > 0) { 1379 if (monotime() >= control_persist_exit_time) { 1380 debug("ControlPersist timeout expired"); 1381 break; 1382 } 1383 } 1384 } 1385 free(readset); 1386 free(writeset); 1387 1388 /* Terminate the session. */ 1389 1390 /* Stop watching for window change. */ 1391 ssh_signal(SIGWINCH, SIG_DFL); 1392 1393 if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 || 1394 (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_BY_APPLICATION)) != 0 || 1395 (r = sshpkt_put_cstring(ssh, "disconnected by user")) != 0 || 1396 (r = sshpkt_put_cstring(ssh, "")) != 0 || /* language tag */ 1397 (r = sshpkt_send(ssh)) != 0 || 1398 (r = ssh_packet_write_wait(ssh)) != 0) 1399 fatal_fr(r, "send disconnect"); 1400 1401 channel_free_all(ssh); 1402 1403 if (have_pty) 1404 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 1405 1406 /* restore blocking io */ 1407 if (!isatty(fileno(stdin))) 1408 unset_nonblock(fileno(stdin)); 1409 if (!isatty(fileno(stdout))) 1410 unset_nonblock(fileno(stdout)); 1411 if (!isatty(fileno(stderr))) 1412 unset_nonblock(fileno(stderr)); 1413 1414 /* 1415 * If there was no shell or command requested, there will be no remote 1416 * exit status to be returned. In that case, clear error code if the 1417 * connection was deliberately terminated at this end. 1418 */ 1419 if (no_shell_flag && received_signal == SIGTERM) { 1420 received_signal = 0; 1421 exit_status = 0; 1422 } 1423 1424 if (received_signal) { 1425 verbose("Killed by signal %d.", (int) received_signal); 1426 cleanup_exit(0); 1427 } 1428 1429 /* 1430 * In interactive mode (with pseudo tty) display a message indicating 1431 * that the connection has been closed. 1432 */ 1433 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) { 1434 if ((r = sshbuf_putf(stderr_buffer, 1435 "Connection to %.64s closed.\r\n", host)) != 0) 1436 fatal_fr(r, "sshbuf_putf"); 1437 } 1438 1439 /* Output any buffered data for stderr. */ 1440 if (sshbuf_len(stderr_buffer) > 0) { 1441 len = atomicio(vwrite, fileno(stderr), 1442 (u_char *)sshbuf_ptr(stderr_buffer), 1443 sshbuf_len(stderr_buffer)); 1444 if (len < 0 || (u_int)len != sshbuf_len(stderr_buffer)) 1445 error("Write failed flushing stderr buffer."); 1446 else if ((r = sshbuf_consume(stderr_buffer, len)) != 0) 1447 fatal_fr(r, "sshbuf_consume"); 1448 } 1449 1450 /* Clear and free any buffers. */ 1451 sshbuf_free(stderr_buffer); 1452 1453 /* Report bytes transferred, and transfer rates. */ 1454 total_time = monotime_double() - start_time; 1455 ssh_packet_get_bytes(ssh, &ibytes, &obytes); 1456 verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds", 1457 (unsigned long long)obytes, (unsigned long long)ibytes, total_time); 1458 if (total_time > 0) 1459 verbose("Bytes per second: sent %.1f, received %.1f", 1460 obytes / total_time, ibytes / total_time); 1461 /* Return the exit status of the program. */ 1462 debug("Exit status %d", exit_status); 1463 return exit_status; 1464 } 1465 1466 /*********/ 1467 1468 static Channel * 1469 client_request_forwarded_tcpip(struct ssh *ssh, const char *request_type, 1470 int rchan, u_int rwindow, u_int rmaxpack) 1471 { 1472 Channel *c = NULL; 1473 struct sshbuf *b = NULL; 1474 char *listen_address, *originator_address; 1475 u_int listen_port, originator_port; 1476 int r; 1477 1478 /* Get rest of the packet */ 1479 if ((r = sshpkt_get_cstring(ssh, &listen_address, NULL)) != 0 || 1480 (r = sshpkt_get_u32(ssh, &listen_port)) != 0 || 1481 (r = sshpkt_get_cstring(ssh, &originator_address, NULL)) != 0 || 1482 (r = sshpkt_get_u32(ssh, &originator_port)) != 0 || 1483 (r = sshpkt_get_end(ssh)) != 0) 1484 fatal_fr(r, "parse packet"); 1485 1486 debug_f("listen %s port %d, originator %s port %d", 1487 listen_address, listen_port, originator_address, originator_port); 1488 1489 if (listen_port > 0xffff) 1490 error_f("invalid listen port"); 1491 else if (originator_port > 0xffff) 1492 error_f("invalid originator port"); 1493 else { 1494 c = channel_connect_by_listen_address(ssh, 1495 listen_address, listen_port, "forwarded-tcpip", 1496 originator_address); 1497 } 1498 1499 if (c != NULL && c->type == SSH_CHANNEL_MUX_CLIENT) { 1500 if ((b = sshbuf_new()) == NULL) { 1501 error_f("alloc reply"); 1502 goto out; 1503 } 1504 /* reconstruct and send to muxclient */ 1505 if ((r = sshbuf_put_u8(b, 0)) != 0 || /* padlen */ 1506 (r = sshbuf_put_u8(b, SSH2_MSG_CHANNEL_OPEN)) != 0 || 1507 (r = sshbuf_put_cstring(b, request_type)) != 0 || 1508 (r = sshbuf_put_u32(b, rchan)) != 0 || 1509 (r = sshbuf_put_u32(b, rwindow)) != 0 || 1510 (r = sshbuf_put_u32(b, rmaxpack)) != 0 || 1511 (r = sshbuf_put_cstring(b, listen_address)) != 0 || 1512 (r = sshbuf_put_u32(b, listen_port)) != 0 || 1513 (r = sshbuf_put_cstring(b, originator_address)) != 0 || 1514 (r = sshbuf_put_u32(b, originator_port)) != 0 || 1515 (r = sshbuf_put_stringb(c->output, b)) != 0) { 1516 error_fr(r, "compose for muxclient"); 1517 goto out; 1518 } 1519 } 1520 1521 out: 1522 sshbuf_free(b); 1523 free(originator_address); 1524 free(listen_address); 1525 return c; 1526 } 1527 1528 static Channel * 1529 client_request_forwarded_streamlocal(struct ssh *ssh, 1530 const char *request_type, int rchan) 1531 { 1532 Channel *c = NULL; 1533 char *listen_path; 1534 int r; 1535 1536 /* Get the remote path. */ 1537 if ((r = sshpkt_get_cstring(ssh, &listen_path, NULL)) != 0 || 1538 (r = sshpkt_get_string(ssh, NULL, NULL)) != 0 || /* reserved */ 1539 (r = sshpkt_get_end(ssh)) != 0) 1540 fatal_fr(r, "parse packet"); 1541 1542 debug_f("request: %s", listen_path); 1543 1544 c = channel_connect_by_listen_path(ssh, listen_path, 1545 "forwarded-streamlocal@openssh.com", "forwarded-streamlocal"); 1546 free(listen_path); 1547 return c; 1548 } 1549 1550 static Channel * 1551 client_request_x11(struct ssh *ssh, const char *request_type, int rchan) 1552 { 1553 Channel *c = NULL; 1554 char *originator; 1555 u_int originator_port; 1556 int r, sock; 1557 1558 if (!options.forward_x11) { 1559 error("Warning: ssh server tried X11 forwarding."); 1560 error("Warning: this is probably a break-in attempt by a " 1561 "malicious server."); 1562 return NULL; 1563 } 1564 if (x11_refuse_time != 0 && (u_int)monotime() >= x11_refuse_time) { 1565 verbose("Rejected X11 connection after ForwardX11Timeout " 1566 "expired"); 1567 return NULL; 1568 } 1569 if ((r = sshpkt_get_cstring(ssh, &originator, NULL)) != 0 || 1570 (r = sshpkt_get_u32(ssh, &originator_port)) != 0 || 1571 (r = sshpkt_get_end(ssh)) != 0) 1572 fatal_fr(r, "parse packet"); 1573 /* XXX check permission */ 1574 /* XXX range check originator port? */ 1575 debug("client_request_x11: request from %s %u", originator, 1576 originator_port); 1577 free(originator); 1578 sock = x11_connect_display(ssh); 1579 if (sock < 0) 1580 return NULL; 1581 c = channel_new(ssh, "x11", 1582 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 1583 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1); 1584 c->force_drain = 1; 1585 return c; 1586 } 1587 1588 static Channel * 1589 client_request_agent(struct ssh *ssh, const char *request_type, int rchan) 1590 { 1591 Channel *c = NULL; 1592 int r, sock; 1593 1594 if (!options.forward_agent) { 1595 error("Warning: ssh server tried agent forwarding."); 1596 error("Warning: this is probably a break-in attempt by a " 1597 "malicious server."); 1598 return NULL; 1599 } 1600 if (forward_agent_sock_path == NULL) { 1601 r = ssh_get_authentication_socket(&sock); 1602 } else { 1603 r = ssh_get_authentication_socket_path(forward_agent_sock_path, &sock); 1604 } 1605 if (r != 0) { 1606 if (r != SSH_ERR_AGENT_NOT_PRESENT) 1607 debug_fr(r, "ssh_get_authentication_socket"); 1608 return NULL; 1609 } 1610 c = channel_new(ssh, "authentication agent connection", 1611 SSH_CHANNEL_OPEN, sock, sock, -1, 1612 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, 1613 "authentication agent connection", 1); 1614 c->force_drain = 1; 1615 return c; 1616 } 1617 1618 char * 1619 client_request_tun_fwd(struct ssh *ssh, int tun_mode, 1620 int local_tun, int remote_tun, channel_open_fn *cb, void *cbctx) 1621 { 1622 Channel *c; 1623 int r, fd; 1624 char *ifname = NULL; 1625 1626 if (tun_mode == SSH_TUNMODE_NO) 1627 return 0; 1628 1629 debug("Requesting tun unit %d in mode %d", local_tun, tun_mode); 1630 1631 /* Open local tunnel device */ 1632 if ((fd = tun_open(local_tun, tun_mode, &ifname)) == -1) { 1633 error("Tunnel device open failed."); 1634 return NULL; 1635 } 1636 debug("Tunnel forwarding using interface %s", ifname); 1637 1638 c = channel_new(ssh, "tun", SSH_CHANNEL_OPENING, fd, fd, -1, 1639 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); 1640 c->datagram = 1; 1641 1642 #if defined(SSH_TUN_FILTER) 1643 if (options.tun_open == SSH_TUNMODE_POINTOPOINT) 1644 channel_register_filter(ssh, c->self, sys_tun_infilter, 1645 sys_tun_outfilter, NULL, NULL); 1646 #endif 1647 1648 if (cb != NULL) 1649 channel_register_open_confirm(ssh, c->self, cb, cbctx); 1650 1651 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN)) != 0 || 1652 (r = sshpkt_put_cstring(ssh, "tun@openssh.com")) != 0 || 1653 (r = sshpkt_put_u32(ssh, c->self)) != 0 || 1654 (r = sshpkt_put_u32(ssh, c->local_window_max)) != 0 || 1655 (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 || 1656 (r = sshpkt_put_u32(ssh, tun_mode)) != 0 || 1657 (r = sshpkt_put_u32(ssh, remote_tun)) != 0 || 1658 (r = sshpkt_send(ssh)) != 0) 1659 sshpkt_fatal(ssh, r, "%s: send reply", __func__); 1660 1661 return ifname; 1662 } 1663 1664 /* XXXX move to generic input handler */ 1665 static int 1666 client_input_channel_open(int type, u_int32_t seq, struct ssh *ssh) 1667 { 1668 Channel *c = NULL; 1669 char *ctype = NULL; 1670 int r; 1671 u_int rchan; 1672 size_t len; 1673 u_int rmaxpack, rwindow; 1674 1675 if ((r = sshpkt_get_cstring(ssh, &ctype, &len)) != 0 || 1676 (r = sshpkt_get_u32(ssh, &rchan)) != 0 || 1677 (r = sshpkt_get_u32(ssh, &rwindow)) != 0 || 1678 (r = sshpkt_get_u32(ssh, &rmaxpack)) != 0) 1679 goto out; 1680 1681 debug("client_input_channel_open: ctype %s rchan %d win %d max %d", 1682 ctype, rchan, rwindow, rmaxpack); 1683 1684 if (strcmp(ctype, "forwarded-tcpip") == 0) { 1685 c = client_request_forwarded_tcpip(ssh, ctype, rchan, rwindow, 1686 rmaxpack); 1687 } else if (strcmp(ctype, "forwarded-streamlocal@openssh.com") == 0) { 1688 c = client_request_forwarded_streamlocal(ssh, ctype, rchan); 1689 } else if (strcmp(ctype, "x11") == 0) { 1690 c = client_request_x11(ssh, ctype, rchan); 1691 } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) { 1692 c = client_request_agent(ssh, ctype, rchan); 1693 } 1694 if (c != NULL && c->type == SSH_CHANNEL_MUX_CLIENT) { 1695 debug3("proxied to downstream: %s", ctype); 1696 } else if (c != NULL) { 1697 debug("confirm %s", ctype); 1698 c->remote_id = rchan; 1699 c->have_remote_id = 1; 1700 c->remote_window = rwindow; 1701 c->remote_maxpacket = rmaxpack; 1702 if (c->type != SSH_CHANNEL_CONNECTING) { 1703 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 || 1704 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 || 1705 (r = sshpkt_put_u32(ssh, c->self)) != 0 || 1706 (r = sshpkt_put_u32(ssh, c->local_window)) != 0 || 1707 (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 || 1708 (r = sshpkt_send(ssh)) != 0) 1709 sshpkt_fatal(ssh, r, "%s: send reply", __func__); 1710 } 1711 } else { 1712 debug("failure %s", ctype); 1713 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE)) != 0 || 1714 (r = sshpkt_put_u32(ssh, rchan)) != 0 || 1715 (r = sshpkt_put_u32(ssh, SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED)) != 0 || 1716 (r = sshpkt_put_cstring(ssh, "open failed")) != 0 || 1717 (r = sshpkt_put_cstring(ssh, "")) != 0 || 1718 (r = sshpkt_send(ssh)) != 0) 1719 sshpkt_fatal(ssh, r, "%s: send failure", __func__); 1720 } 1721 r = 0; 1722 out: 1723 free(ctype); 1724 return r; 1725 } 1726 1727 static int 1728 client_input_channel_req(int type, u_int32_t seq, struct ssh *ssh) 1729 { 1730 Channel *c = NULL; 1731 char *rtype = NULL; 1732 u_char reply; 1733 u_int id, exitval; 1734 int r, success = 0; 1735 1736 if ((r = sshpkt_get_u32(ssh, &id)) != 0) 1737 return r; 1738 if (id <= INT_MAX) 1739 c = channel_lookup(ssh, id); 1740 if (channel_proxy_upstream(c, type, seq, ssh)) 1741 return 0; 1742 if ((r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 || 1743 (r = sshpkt_get_u8(ssh, &reply)) != 0) 1744 goto out; 1745 1746 debug("client_input_channel_req: channel %u rtype %s reply %d", 1747 id, rtype, reply); 1748 1749 if (c == NULL) { 1750 error("client_input_channel_req: channel %d: " 1751 "unknown channel", id); 1752 } else if (strcmp(rtype, "eow@openssh.com") == 0) { 1753 if ((r = sshpkt_get_end(ssh)) != 0) 1754 goto out; 1755 chan_rcvd_eow(ssh, c); 1756 } else if (strcmp(rtype, "exit-status") == 0) { 1757 if ((r = sshpkt_get_u32(ssh, &exitval)) != 0) 1758 goto out; 1759 if (c->ctl_chan != -1) { 1760 mux_exit_message(ssh, c, exitval); 1761 success = 1; 1762 } else if ((int)id == session_ident) { 1763 /* Record exit value of local session */ 1764 success = 1; 1765 exit_status = exitval; 1766 } else { 1767 /* Probably for a mux channel that has already closed */ 1768 debug_f("no sink for exit-status on channel %d", 1769 id); 1770 } 1771 if ((r = sshpkt_get_end(ssh)) != 0) 1772 goto out; 1773 } 1774 if (reply && c != NULL && !(c->flags & CHAN_CLOSE_SENT)) { 1775 if (!c->have_remote_id) 1776 fatal_f("channel %d: no remote_id", c->self); 1777 if ((r = sshpkt_start(ssh, success ? 1778 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE)) != 0 || 1779 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 || 1780 (r = sshpkt_send(ssh)) != 0) 1781 sshpkt_fatal(ssh, r, "%s: send failure", __func__); 1782 } 1783 r = 0; 1784 out: 1785 free(rtype); 1786 return r; 1787 } 1788 1789 struct hostkeys_update_ctx { 1790 /* The hostname and (optionally) IP address string for the server */ 1791 char *host_str, *ip_str; 1792 1793 /* 1794 * Keys received from the server and a flag for each indicating 1795 * whether they already exist in known_hosts. 1796 * keys_match is filled in by hostkeys_find() and later (for new 1797 * keys) by client_global_hostkeys_private_confirm(). 1798 */ 1799 struct sshkey **keys; 1800 u_int *keys_match; /* mask of HKF_MATCH_* from hostfile.h */ 1801 int *keys_verified; /* flag for new keys verified by server */ 1802 size_t nkeys, nnew, nincomplete; /* total, new keys, incomplete match */ 1803 1804 /* 1805 * Keys that are in known_hosts, but were not present in the update 1806 * from the server (i.e. scheduled to be deleted). 1807 * Filled in by hostkeys_find(). 1808 */ 1809 struct sshkey **old_keys; 1810 size_t nold; 1811 1812 /* Various special cases. */ 1813 int complex_hostspec; /* wildcard or manual pattern-list host name */ 1814 int ca_available; /* saw CA key for this host */ 1815 int old_key_seen; /* saw old key with other name/addr */ 1816 int other_name_seen; /* saw key with other name/addr */ 1817 }; 1818 1819 static void 1820 hostkeys_update_ctx_free(struct hostkeys_update_ctx *ctx) 1821 { 1822 size_t i; 1823 1824 if (ctx == NULL) 1825 return; 1826 for (i = 0; i < ctx->nkeys; i++) 1827 sshkey_free(ctx->keys[i]); 1828 free(ctx->keys); 1829 free(ctx->keys_match); 1830 free(ctx->keys_verified); 1831 for (i = 0; i < ctx->nold; i++) 1832 sshkey_free(ctx->old_keys[i]); 1833 free(ctx->old_keys); 1834 free(ctx->host_str); 1835 free(ctx->ip_str); 1836 free(ctx); 1837 } 1838 1839 /* 1840 * Returns non-zero if a known_hosts hostname list is not of a form that 1841 * can be handled by UpdateHostkeys. These include wildcard hostnames and 1842 * hostnames lists that do not follow the form host[,ip]. 1843 */ 1844 static int 1845 hostspec_is_complex(const char *hosts) 1846 { 1847 char *cp; 1848 1849 /* wildcard */ 1850 if (strchr(hosts, '*') != NULL || strchr(hosts, '?') != NULL) 1851 return 1; 1852 /* single host/ip = ok */ 1853 if ((cp = strchr(hosts, ',')) == NULL) 1854 return 0; 1855 /* more than two entries on the line */ 1856 if (strchr(cp + 1, ',') != NULL) 1857 return 1; 1858 /* XXX maybe parse cp+1 and ensure it is an IP? */ 1859 return 0; 1860 } 1861 1862 /* callback to search for ctx->keys in known_hosts */ 1863 static int 1864 hostkeys_find(struct hostkey_foreach_line *l, void *_ctx) 1865 { 1866 struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx; 1867 size_t i; 1868 struct sshkey **tmp; 1869 1870 if (l->key == NULL) 1871 return 0; 1872 if (l->status != HKF_STATUS_MATCHED) { 1873 /* Record if one of the keys appears on a non-matching line */ 1874 for (i = 0; i < ctx->nkeys; i++) { 1875 if (sshkey_equal(l->key, ctx->keys[i])) { 1876 ctx->other_name_seen = 1; 1877 debug3_f("found %s key under different " 1878 "name/addr at %s:%ld", 1879 sshkey_ssh_name(ctx->keys[i]), 1880 l->path, l->linenum); 1881 return 0; 1882 } 1883 } 1884 return 0; 1885 } 1886 /* Don't proceed if revocation or CA markers are present */ 1887 /* XXX relax this */ 1888 if (l->marker != MRK_NONE) { 1889 debug3_f("hostkeys file %s:%ld has CA/revocation marker", 1890 l->path, l->linenum); 1891 ctx->complex_hostspec = 1; 1892 return 0; 1893 } 1894 1895 /* If CheckHostIP is enabled, then check for mismatched hostname/addr */ 1896 if (ctx->ip_str != NULL && strchr(l->hosts, ',') != NULL) { 1897 if ((l->match & HKF_MATCH_HOST) == 0) { 1898 /* Record if address matched a different hostname. */ 1899 ctx->other_name_seen = 1; 1900 debug3_f("found address %s against different hostname " 1901 "at %s:%ld", ctx->ip_str, l->path, l->linenum); 1902 return 0; 1903 } else if ((l->match & HKF_MATCH_IP) == 0) { 1904 /* Record if hostname matched a different address. */ 1905 ctx->other_name_seen = 1; 1906 debug3_f("found hostname %s against different address " 1907 "at %s:%ld", ctx->host_str, l->path, l->linenum); 1908 } 1909 } 1910 1911 /* 1912 * UpdateHostkeys is skipped for wildcard host names and hostnames 1913 * that contain more than two entries (ssh never writes these). 1914 */ 1915 if (hostspec_is_complex(l->hosts)) { 1916 debug3_f("hostkeys file %s:%ld complex host specification", 1917 l->path, l->linenum); 1918 ctx->complex_hostspec = 1; 1919 return 0; 1920 } 1921 1922 /* Mark off keys we've already seen for this host */ 1923 for (i = 0; i < ctx->nkeys; i++) { 1924 if (!sshkey_equal(l->key, ctx->keys[i])) 1925 continue; 1926 debug3_f("found %s key at %s:%ld", 1927 sshkey_ssh_name(ctx->keys[i]), l->path, l->linenum); 1928 ctx->keys_match[i] |= l->match; 1929 return 0; 1930 } 1931 /* This line contained a key that not offered by the server */ 1932 debug3_f("deprecated %s key at %s:%ld", sshkey_ssh_name(l->key), 1933 l->path, l->linenum); 1934 if ((tmp = recallocarray(ctx->old_keys, ctx->nold, ctx->nold + 1, 1935 sizeof(*ctx->old_keys))) == NULL) 1936 fatal_f("recallocarray failed nold = %zu", ctx->nold); 1937 ctx->old_keys = tmp; 1938 ctx->old_keys[ctx->nold++] = l->key; 1939 l->key = NULL; 1940 1941 return 0; 1942 } 1943 1944 /* callback to search for ctx->old_keys in known_hosts under other names */ 1945 static int 1946 hostkeys_check_old(struct hostkey_foreach_line *l, void *_ctx) 1947 { 1948 struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx; 1949 size_t i; 1950 int hashed; 1951 1952 /* only care about lines that *don't* match the active host spec */ 1953 if (l->status == HKF_STATUS_MATCHED || l->key == NULL) 1954 return 0; 1955 1956 hashed = l->match & (HKF_MATCH_HOST_HASHED|HKF_MATCH_IP_HASHED); 1957 for (i = 0; i < ctx->nold; i++) { 1958 if (!sshkey_equal(l->key, ctx->old_keys[i])) 1959 continue; 1960 debug3_f("found deprecated %s key at %s:%ld as %s", 1961 sshkey_ssh_name(ctx->keys[i]), l->path, l->linenum, 1962 hashed ? "[HASHED]" : l->hosts); 1963 ctx->old_key_seen = 1; 1964 break; 1965 } 1966 return 0; 1967 } 1968 1969 /* 1970 * Check known_hosts files for deprecated keys under other names. Returns 0 1971 * on success or -1 on failure. Updates ctx->old_key_seen if deprecated keys 1972 * exist under names other than the active hostname/IP. 1973 */ 1974 static int 1975 check_old_keys_othernames(struct hostkeys_update_ctx *ctx) 1976 { 1977 size_t i; 1978 int r; 1979 1980 debug2_f("checking for %zu deprecated keys", ctx->nold); 1981 for (i = 0; i < options.num_user_hostfiles; i++) { 1982 debug3_f("searching %s for %s / %s", 1983 options.user_hostfiles[i], ctx->host_str, 1984 ctx->ip_str ? ctx->ip_str : "(none)"); 1985 if ((r = hostkeys_foreach(options.user_hostfiles[i], 1986 hostkeys_check_old, ctx, ctx->host_str, ctx->ip_str, 1987 HKF_WANT_PARSE_KEY, 0)) != 0) { 1988 if (r == SSH_ERR_SYSTEM_ERROR && errno == ENOENT) { 1989 debug_f("hostkeys file %s does not exist", 1990 options.user_hostfiles[i]); 1991 continue; 1992 } 1993 error_fr(r, "hostkeys_foreach failed for %s", 1994 options.user_hostfiles[i]); 1995 return -1; 1996 } 1997 } 1998 return 0; 1999 } 2000 2001 static void 2002 hostkey_change_preamble(LogLevel loglevel) 2003 { 2004 do_log2(loglevel, "The server has updated its host keys."); 2005 do_log2(loglevel, "These changes were verified by the server's " 2006 "existing trusted key."); 2007 } 2008 2009 static void 2010 update_known_hosts(struct hostkeys_update_ctx *ctx) 2011 { 2012 int r, was_raw = 0, first = 1; 2013 int asking = options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK; 2014 LogLevel loglevel = asking ? SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_VERBOSE; 2015 char *fp, *response; 2016 size_t i; 2017 struct stat sb; 2018 2019 for (i = 0; i < ctx->nkeys; i++) { 2020 if (!ctx->keys_verified[i]) 2021 continue; 2022 if ((fp = sshkey_fingerprint(ctx->keys[i], 2023 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) 2024 fatal_f("sshkey_fingerprint failed"); 2025 if (first && asking) 2026 hostkey_change_preamble(loglevel); 2027 do_log2(loglevel, "Learned new hostkey: %s %s", 2028 sshkey_type(ctx->keys[i]), fp); 2029 first = 0; 2030 free(fp); 2031 } 2032 for (i = 0; i < ctx->nold; i++) { 2033 if ((fp = sshkey_fingerprint(ctx->old_keys[i], 2034 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) 2035 fatal_f("sshkey_fingerprint failed"); 2036 if (first && asking) 2037 hostkey_change_preamble(loglevel); 2038 do_log2(loglevel, "Deprecating obsolete hostkey: %s %s", 2039 sshkey_type(ctx->old_keys[i]), fp); 2040 first = 0; 2041 free(fp); 2042 } 2043 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { 2044 if (get_saved_tio() != NULL) { 2045 leave_raw_mode(1); 2046 was_raw = 1; 2047 } 2048 response = NULL; 2049 for (i = 0; !quit_pending && i < 3; i++) { 2050 free(response); 2051 response = read_passphrase("Accept updated hostkeys? " 2052 "(yes/no): ", RP_ECHO); 2053 if (strcasecmp(response, "yes") == 0) 2054 break; 2055 else if (quit_pending || response == NULL || 2056 strcasecmp(response, "no") == 0) { 2057 options.update_hostkeys = 0; 2058 break; 2059 } else { 2060 do_log2(loglevel, "Please enter " 2061 "\"yes\" or \"no\""); 2062 } 2063 } 2064 if (quit_pending || i >= 3 || response == NULL) 2065 options.update_hostkeys = 0; 2066 free(response); 2067 if (was_raw) 2068 enter_raw_mode(1); 2069 } 2070 if (options.update_hostkeys == 0) 2071 return; 2072 /* 2073 * Now that all the keys are verified, we can go ahead and replace 2074 * them in known_hosts (assuming SSH_UPDATE_HOSTKEYS_ASK didn't 2075 * cancel the operation). 2076 */ 2077 for (i = 0; i < options.num_user_hostfiles; i++) { 2078 /* 2079 * NB. keys are only added to hostfiles[0], for the rest we 2080 * just delete the hostname entries. 2081 */ 2082 if (stat(options.user_hostfiles[i], &sb) != 0) { 2083 if (errno == ENOENT) { 2084 debug_f("known hosts file %s does not " 2085 "exist", options.user_hostfiles[i]); 2086 } else { 2087 error_f("known hosts file %s " 2088 "inaccessible: %s", 2089 options.user_hostfiles[i], strerror(errno)); 2090 } 2091 continue; 2092 } 2093 if ((r = hostfile_replace_entries(options.user_hostfiles[i], 2094 ctx->host_str, ctx->ip_str, 2095 i == 0 ? ctx->keys : NULL, i == 0 ? ctx->nkeys : 0, 2096 options.hash_known_hosts, 0, 2097 options.fingerprint_hash)) != 0) { 2098 error_fr(r, "hostfile_replace_entries failed for %s", 2099 options.user_hostfiles[i]); 2100 } 2101 } 2102 } 2103 2104 static void 2105 client_global_hostkeys_private_confirm(struct ssh *ssh, int type, 2106 u_int32_t seq, void *_ctx) 2107 { 2108 struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx; 2109 size_t i, ndone; 2110 struct sshbuf *signdata; 2111 int r, kexsigtype, use_kexsigtype; 2112 const u_char *sig; 2113 size_t siglen; 2114 2115 if (ctx->nnew == 0) 2116 fatal_f("ctx->nnew == 0"); /* sanity */ 2117 if (type != SSH2_MSG_REQUEST_SUCCESS) { 2118 error("Server failed to confirm ownership of " 2119 "private host keys"); 2120 hostkeys_update_ctx_free(ctx); 2121 return; 2122 } 2123 kexsigtype = sshkey_type_plain( 2124 sshkey_type_from_name(ssh->kex->hostkey_alg)); 2125 2126 if ((signdata = sshbuf_new()) == NULL) 2127 fatal_f("sshbuf_new failed"); 2128 /* 2129 * Expect a signature for each of the ctx->nnew private keys we 2130 * haven't seen before. They will be in the same order as the 2131 * ctx->keys where the corresponding ctx->keys_match[i] == 0. 2132 */ 2133 for (ndone = i = 0; i < ctx->nkeys; i++) { 2134 if (ctx->keys_match[i]) 2135 continue; 2136 /* Prepare data to be signed: session ID, unique string, key */ 2137 sshbuf_reset(signdata); 2138 if ( (r = sshbuf_put_cstring(signdata, 2139 "hostkeys-prove-00@openssh.com")) != 0 || 2140 (r = sshbuf_put_stringb(signdata, 2141 ssh->kex->session_id)) != 0 || 2142 (r = sshkey_puts(ctx->keys[i], signdata)) != 0) 2143 fatal_fr(r, "compose signdata"); 2144 /* Extract and verify signature */ 2145 if ((r = sshpkt_get_string_direct(ssh, &sig, &siglen)) != 0) { 2146 error_fr(r, "parse sig"); 2147 goto out; 2148 } 2149 /* 2150 * For RSA keys, prefer to use the signature type negotiated 2151 * during KEX to the default (SHA1). 2152 */ 2153 use_kexsigtype = kexsigtype == KEY_RSA && 2154 sshkey_type_plain(ctx->keys[i]->type) == KEY_RSA; 2155 if ((r = sshkey_verify(ctx->keys[i], sig, siglen, 2156 sshbuf_ptr(signdata), sshbuf_len(signdata), 2157 use_kexsigtype ? ssh->kex->hostkey_alg : NULL, 0, 2158 NULL)) != 0) { 2159 error_f("server gave bad signature for %s key %zu", 2160 sshkey_type(ctx->keys[i]), i); 2161 goto out; 2162 } 2163 /* Key is good. Mark it as 'seen' */ 2164 ctx->keys_verified[i] = 1; 2165 ndone++; 2166 } 2167 /* Shouldn't happen */ 2168 if (ndone != ctx->nnew) 2169 fatal_f("ndone != ctx->nnew (%zu / %zu)", ndone, ctx->nnew); 2170 if ((r = sshpkt_get_end(ssh)) != 0) { 2171 error_f("protocol error"); 2172 goto out; 2173 } 2174 2175 /* Make the edits to known_hosts */ 2176 update_known_hosts(ctx); 2177 out: 2178 hostkeys_update_ctx_free(ctx); 2179 } 2180 2181 /* 2182 * Returns non-zero if the key is accepted by HostkeyAlgorithms. 2183 * Made slightly less trivial by the multiple RSA signature algorithm names. 2184 */ 2185 static int 2186 key_accepted_by_hostkeyalgs(const struct sshkey *key) 2187 { 2188 const char *ktype = sshkey_ssh_name(key); 2189 const char *hostkeyalgs = options.hostkeyalgorithms; 2190 2191 if (key == NULL || key->type == KEY_UNSPEC) 2192 return 0; 2193 if (key->type == KEY_RSA && 2194 (match_pattern_list("rsa-sha2-256", hostkeyalgs, 0) == 1 || 2195 match_pattern_list("rsa-sha2-512", hostkeyalgs, 0) == 1)) 2196 return 1; 2197 return match_pattern_list(ktype, hostkeyalgs, 0) == 1; 2198 } 2199 2200 /* 2201 * Handle hostkeys-00@openssh.com global request to inform the client of all 2202 * the server's hostkeys. The keys are checked against the user's 2203 * HostkeyAlgorithms preference before they are accepted. 2204 */ 2205 static int 2206 client_input_hostkeys(struct ssh *ssh) 2207 { 2208 const u_char *blob = NULL; 2209 size_t i, len = 0; 2210 struct sshbuf *buf = NULL; 2211 struct sshkey *key = NULL, **tmp; 2212 int r; 2213 char *fp; 2214 static int hostkeys_seen = 0; /* XXX use struct ssh */ 2215 extern struct sockaddr_storage hostaddr; /* XXX from ssh.c */ 2216 struct hostkeys_update_ctx *ctx = NULL; 2217 u_int want; 2218 2219 if (hostkeys_seen) 2220 fatal_f("server already sent hostkeys"); 2221 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK && 2222 options.batch_mode) 2223 return 1; /* won't ask in batchmode, so don't even try */ 2224 if (!options.update_hostkeys || options.num_user_hostfiles <= 0) 2225 return 1; 2226 2227 ctx = xcalloc(1, sizeof(*ctx)); 2228 while (ssh_packet_remaining(ssh) > 0) { 2229 sshkey_free(key); 2230 key = NULL; 2231 if ((r = sshpkt_get_string_direct(ssh, &blob, &len)) != 0) { 2232 error_fr(r, "parse key"); 2233 goto out; 2234 } 2235 if ((r = sshkey_from_blob(blob, len, &key)) != 0) { 2236 do_log2_fr(r, r == SSH_ERR_KEY_TYPE_UNKNOWN ? 2237 SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_ERROR, 2238 "convert key"); 2239 continue; 2240 } 2241 fp = sshkey_fingerprint(key, options.fingerprint_hash, 2242 SSH_FP_DEFAULT); 2243 debug3_f("received %s key %s", sshkey_type(key), fp); 2244 free(fp); 2245 2246 if (!key_accepted_by_hostkeyalgs(key)) { 2247 debug3_f("%s key not permitted by " 2248 "HostkeyAlgorithms", sshkey_ssh_name(key)); 2249 continue; 2250 } 2251 /* Skip certs */ 2252 if (sshkey_is_cert(key)) { 2253 debug3_f("%s key is a certificate; skipping", 2254 sshkey_ssh_name(key)); 2255 continue; 2256 } 2257 /* Ensure keys are unique */ 2258 for (i = 0; i < ctx->nkeys; i++) { 2259 if (sshkey_equal(key, ctx->keys[i])) { 2260 error_f("received duplicated %s host key", 2261 sshkey_ssh_name(key)); 2262 goto out; 2263 } 2264 } 2265 /* Key is good, record it */ 2266 if ((tmp = recallocarray(ctx->keys, ctx->nkeys, ctx->nkeys + 1, 2267 sizeof(*ctx->keys))) == NULL) 2268 fatal_f("recallocarray failed nkeys = %zu", 2269 ctx->nkeys); 2270 ctx->keys = tmp; 2271 ctx->keys[ctx->nkeys++] = key; 2272 key = NULL; 2273 } 2274 2275 if (ctx->nkeys == 0) { 2276 debug_f("server sent no hostkeys"); 2277 goto out; 2278 } 2279 2280 if ((ctx->keys_match = calloc(ctx->nkeys, 2281 sizeof(*ctx->keys_match))) == NULL || 2282 (ctx->keys_verified = calloc(ctx->nkeys, 2283 sizeof(*ctx->keys_verified))) == NULL) 2284 fatal_f("calloc failed"); 2285 2286 get_hostfile_hostname_ipaddr(host, 2287 options.check_host_ip ? (struct sockaddr *)&hostaddr : NULL, 2288 options.port, &ctx->host_str, 2289 options.check_host_ip ? &ctx->ip_str : NULL); 2290 2291 /* Find which keys we already know about. */ 2292 for (i = 0; i < options.num_user_hostfiles; i++) { 2293 debug_f("searching %s for %s / %s", 2294 options.user_hostfiles[i], ctx->host_str, 2295 ctx->ip_str ? ctx->ip_str : "(none)"); 2296 if ((r = hostkeys_foreach(options.user_hostfiles[i], 2297 hostkeys_find, ctx, ctx->host_str, ctx->ip_str, 2298 HKF_WANT_PARSE_KEY, 0)) != 0) { 2299 if (r == SSH_ERR_SYSTEM_ERROR && errno == ENOENT) { 2300 debug_f("hostkeys file %s does not exist", 2301 options.user_hostfiles[i]); 2302 continue; 2303 } 2304 error_fr(r, "hostkeys_foreach failed for %s", 2305 options.user_hostfiles[i]); 2306 goto out; 2307 } 2308 } 2309 2310 /* Figure out if we have any new keys to add */ 2311 ctx->nnew = ctx->nincomplete = 0; 2312 want = HKF_MATCH_HOST | ( options.check_host_ip ? HKF_MATCH_IP : 0); 2313 for (i = 0; i < ctx->nkeys; i++) { 2314 if (ctx->keys_match[i] == 0) 2315 ctx->nnew++; 2316 if ((ctx->keys_match[i] & want) != want) 2317 ctx->nincomplete++; 2318 } 2319 2320 debug3_f("%zu server keys: %zu new, %zu retained, " 2321 "%zu incomplete match. %zu to remove", ctx->nkeys, ctx->nnew, 2322 ctx->nkeys - ctx->nnew - ctx->nincomplete, 2323 ctx->nincomplete, ctx->nold); 2324 2325 if (ctx->nnew == 0 && ctx->nold == 0) { 2326 debug_f("no new or deprecated keys from server"); 2327 goto out; 2328 } 2329 2330 /* Various reasons why we cannot proceed with the update */ 2331 if (ctx->complex_hostspec) { 2332 debug_f("CA/revocation marker, manual host list or wildcard " 2333 "host pattern found, skipping UserKnownHostsFile update"); 2334 goto out; 2335 } 2336 if (ctx->other_name_seen) { 2337 debug_f("host key found matching a different name/address, " 2338 "skipping UserKnownHostsFile update"); 2339 goto out; 2340 } 2341 /* 2342 * If removing keys, check whether they appear under different 2343 * names/addresses and refuse to proceed if they do. This avoids 2344 * cases such as hosts with multiple names becoming inconsistent 2345 * with regards to CheckHostIP entries. 2346 * XXX UpdateHostkeys=force to override this (and other) checks? 2347 */ 2348 if (ctx->nold != 0) { 2349 if (check_old_keys_othernames(ctx) != 0) 2350 goto out; /* error already logged */ 2351 if (ctx->old_key_seen) { 2352 debug_f("key(s) for %s%s%s exist under other names; " 2353 "skipping UserKnownHostsFile update", 2354 ctx->host_str, ctx->ip_str == NULL ? "" : ",", 2355 ctx->ip_str == NULL ? "" : ctx->ip_str); 2356 goto out; 2357 } 2358 } 2359 2360 if (ctx->nnew == 0) { 2361 /* 2362 * We have some keys to remove or fix matching for. 2363 * We can proceed to do this without requiring a fresh proof 2364 * from the server. 2365 */ 2366 update_known_hosts(ctx); 2367 goto out; 2368 } 2369 /* 2370 * We have received previously-unseen keys from the server. 2371 * Ask the server to confirm ownership of the private halves. 2372 */ 2373 debug3_f("asking server to prove ownership for %zu keys", ctx->nnew); 2374 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || 2375 (r = sshpkt_put_cstring(ssh, 2376 "hostkeys-prove-00@openssh.com")) != 0 || 2377 (r = sshpkt_put_u8(ssh, 1)) != 0) /* bool: want reply */ 2378 fatal_fr(r, "prepare hostkeys-prove"); 2379 if ((buf = sshbuf_new()) == NULL) 2380 fatal_f("sshbuf_new"); 2381 for (i = 0; i < ctx->nkeys; i++) { 2382 if (ctx->keys_match[i]) 2383 continue; 2384 sshbuf_reset(buf); 2385 if ((r = sshkey_putb(ctx->keys[i], buf)) != 0 || 2386 (r = sshpkt_put_stringb(ssh, buf)) != 0) 2387 fatal_fr(r, "assemble hostkeys-prove"); 2388 } 2389 if ((r = sshpkt_send(ssh)) != 0) 2390 fatal_fr(r, "send hostkeys-prove"); 2391 client_register_global_confirm( 2392 client_global_hostkeys_private_confirm, ctx); 2393 ctx = NULL; /* will be freed in callback */ 2394 2395 /* Success */ 2396 out: 2397 hostkeys_update_ctx_free(ctx); 2398 sshkey_free(key); 2399 sshbuf_free(buf); 2400 /* 2401 * NB. Return success for all cases. The server doesn't need to know 2402 * what the client does with its hosts file. 2403 */ 2404 return 1; 2405 } 2406 2407 static int 2408 client_input_global_request(int type, u_int32_t seq, struct ssh *ssh) 2409 { 2410 char *rtype; 2411 u_char want_reply; 2412 int r, success = 0; 2413 2414 if ((r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 || 2415 (r = sshpkt_get_u8(ssh, &want_reply)) != 0) 2416 goto out; 2417 debug("client_input_global_request: rtype %s want_reply %d", 2418 rtype, want_reply); 2419 if (strcmp(rtype, "hostkeys-00@openssh.com") == 0) 2420 success = client_input_hostkeys(ssh); 2421 if (want_reply) { 2422 if ((r = sshpkt_start(ssh, success ? SSH2_MSG_REQUEST_SUCCESS : 2423 SSH2_MSG_REQUEST_FAILURE)) != 0 || 2424 (r = sshpkt_send(ssh)) != 0 || 2425 (r = ssh_packet_write_wait(ssh)) != 0) 2426 goto out; 2427 } 2428 r = 0; 2429 out: 2430 free(rtype); 2431 return r; 2432 } 2433 2434 static void 2435 client_send_env(struct ssh *ssh, int id, const char *name, const char *val) 2436 { 2437 int r; 2438 2439 debug("channel %d: setting env %s = \"%s\"", id, name, val); 2440 channel_request_start(ssh, id, "env", 0); 2441 if ((r = sshpkt_put_cstring(ssh, name)) != 0 || 2442 (r = sshpkt_put_cstring(ssh, val)) != 0 || 2443 (r = sshpkt_send(ssh)) != 0) 2444 fatal_fr(r, "send setenv"); 2445 } 2446 2447 void 2448 client_session2_setup(struct ssh *ssh, int id, int want_tty, int want_subsystem, 2449 const char *term, struct termios *tiop, int in_fd, struct sshbuf *cmd, 2450 char **env) 2451 { 2452 int i, j, matched, len, r; 2453 char *name, *val; 2454 Channel *c = NULL; 2455 2456 debug2_f("id %d", id); 2457 2458 if ((c = channel_lookup(ssh, id)) == NULL) 2459 fatal_f("channel %d: unknown channel", id); 2460 2461 ssh_packet_set_interactive(ssh, want_tty, 2462 options.ip_qos_interactive, options.ip_qos_bulk); 2463 2464 if (want_tty) { 2465 struct winsize ws; 2466 2467 /* Store window size in the packet. */ 2468 if (ioctl(in_fd, TIOCGWINSZ, &ws) == -1) 2469 memset(&ws, 0, sizeof(ws)); 2470 2471 channel_request_start(ssh, id, "pty-req", 1); 2472 client_expect_confirm(ssh, id, "PTY allocation", CONFIRM_TTY); 2473 if ((r = sshpkt_put_cstring(ssh, term != NULL ? term : "")) 2474 != 0 || 2475 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_col)) != 0 || 2476 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_row)) != 0 || 2477 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_xpixel)) != 0 || 2478 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_ypixel)) != 0) 2479 fatal_fr(r, "build pty-req"); 2480 if (tiop == NULL) 2481 tiop = get_saved_tio(); 2482 ssh_tty_make_modes(ssh, -1, tiop); 2483 if ((r = sshpkt_send(ssh)) != 0) 2484 fatal_fr(r, "send pty-req"); 2485 /* XXX wait for reply */ 2486 c->client_tty = 1; 2487 } 2488 2489 /* Transfer any environment variables from client to server */ 2490 if (options.num_send_env != 0 && env != NULL) { 2491 debug("Sending environment."); 2492 for (i = 0; env[i] != NULL; i++) { 2493 /* Split */ 2494 name = xstrdup(env[i]); 2495 if ((val = strchr(name, '=')) == NULL) { 2496 free(name); 2497 continue; 2498 } 2499 *val++ = '\0'; 2500 2501 matched = 0; 2502 for (j = 0; j < options.num_send_env; j++) { 2503 if (match_pattern(name, options.send_env[j])) { 2504 matched = 1; 2505 break; 2506 } 2507 } 2508 if (!matched) { 2509 debug3("Ignored env %s", name); 2510 free(name); 2511 continue; 2512 } 2513 client_send_env(ssh, id, name, val); 2514 free(name); 2515 } 2516 } 2517 for (i = 0; i < options.num_setenv; i++) { 2518 /* Split */ 2519 name = xstrdup(options.setenv[i]); 2520 if ((val = strchr(name, '=')) == NULL) { 2521 free(name); 2522 continue; 2523 } 2524 *val++ = '\0'; 2525 client_send_env(ssh, id, name, val); 2526 free(name); 2527 } 2528 2529 len = sshbuf_len(cmd); 2530 if (len > 0) { 2531 if (len > 900) 2532 len = 900; 2533 if (want_subsystem) { 2534 debug("Sending subsystem: %.*s", 2535 len, (const u_char*)sshbuf_ptr(cmd)); 2536 channel_request_start(ssh, id, "subsystem", 1); 2537 client_expect_confirm(ssh, id, "subsystem", 2538 CONFIRM_CLOSE); 2539 } else { 2540 debug("Sending command: %.*s", 2541 len, (const u_char*)sshbuf_ptr(cmd)); 2542 channel_request_start(ssh, id, "exec", 1); 2543 client_expect_confirm(ssh, id, "exec", CONFIRM_CLOSE); 2544 } 2545 if ((r = sshpkt_put_stringb(ssh, cmd)) != 0 || 2546 (r = sshpkt_send(ssh)) != 0) 2547 fatal_fr(r, "send command"); 2548 } else { 2549 channel_request_start(ssh, id, "shell", 1); 2550 client_expect_confirm(ssh, id, "shell", CONFIRM_CLOSE); 2551 if ((r = sshpkt_send(ssh)) != 0) 2552 fatal_fr(r, "send shell"); 2553 } 2554 } 2555 2556 static void 2557 client_init_dispatch(struct ssh *ssh) 2558 { 2559 ssh_dispatch_init(ssh, &dispatch_protocol_error); 2560 2561 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); 2562 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_DATA, &channel_input_data); 2563 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); 2564 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); 2565 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open); 2566 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); 2567 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); 2568 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req); 2569 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); 2570 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm); 2571 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm); 2572 ssh_dispatch_set(ssh, SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request); 2573 2574 /* rekeying */ 2575 ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, &kex_input_kexinit); 2576 2577 /* global request reply messages */ 2578 ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply); 2579 ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply); 2580 } 2581 2582 void 2583 client_stop_mux(void) 2584 { 2585 if (options.control_path != NULL && muxserver_sock != -1) 2586 unlink(options.control_path); 2587 /* 2588 * If we are in persist mode, or don't have a shell, signal that we 2589 * should close when all active channels are closed. 2590 */ 2591 if (options.control_persist || no_shell_flag) { 2592 session_closed = 1; 2593 setproctitle("[stopped mux]"); 2594 } 2595 } 2596 2597 /* client specific fatal cleanup */ 2598 void 2599 cleanup_exit(int i) 2600 { 2601 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); 2602 if (options.control_path != NULL && muxserver_sock != -1) 2603 unlink(options.control_path); 2604 ssh_kill_proxy_command(); 2605 _exit(i); 2606 } 2607