1 /* $OpenBSD: clientloop.c,v 1.378 2022/01/22 00:49:34 djm Exp $ */
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * The main loop for the interactive session (client side).
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".
15 * Copyright (c) 1999 Theo de Raadt. All rights reserved.
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
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.
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.
38 * SSH2 support added by Markus Friedl.
39 * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved.
41 * Redistribution and use in source and binary forms, with or without
42 * modification, are permitted provided that the following conditions
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.
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.
64 #include <sys/types.h>
65 #include <sys/ioctl.h>
66 #ifdef HAVE_SYS_STAT_H
67 # include <sys/stat.h>
69 #ifdef HAVE_SYS_TIME_H
70 # include <sys/time.h>
72 #include <sys/socket.h>
92 #include "openbsd-compat/sys-queue.h"
100 #include "dispatch.h"
104 #include "myproposal.h"
107 #include "readconf.h"
108 #include "clientloop.h"
109 #include "sshconnect.h"
111 #include "atomicio.h"
116 #include "hostfile.h"
118 /* Permitted RSA signature algorithms for UpdateHostkeys proofs */
119 #define HOSTKEY_PROOF_RSA_ALGS "rsa-sha2-512,rsa-sha2-256"
122 extern Options options;
125 extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */
128 * Name of the host we are connecting to. This is the name given on the
129 * command line, or the Hostname specified for the user-supplied name in a
130 * configuration file.
135 * If this field is not NULL, the ForwardAgent socket is this path and different
136 * instead of SSH_AUTH_SOCK.
138 extern char *forward_agent_sock_path;
141 * Flag to indicate that we have received a window change signal which has
142 * not yet been processed. This will cause a message indicating the new
143 * window size to be sent to the server a little later. This is volatile
144 * because this is updated in a signal handler.
146 static volatile sig_atomic_t received_window_change_signal = 0;
147 static volatile sig_atomic_t received_signal = 0;
149 /* Time when backgrounded control master using ControlPersist should exit */
150 static time_t control_persist_exit_time = 0;
152 /* Common data for the client loop code. */
153 volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */
154 static int last_was_cr; /* Last character was a newline. */
155 static int exit_status; /* Used to store the command exit status. */
156 static struct sshbuf *stderr_buffer; /* Used for final exit message. */
157 static int connection_in; /* Connection to server (input). */
158 static int connection_out; /* Connection to server (output). */
159 static int need_rekeying; /* Set to non-zero if rekeying is requested. */
160 static int session_closed; /* In SSH2: login session closed. */
161 static u_int x11_refuse_time; /* If >0, refuse x11 opens after this time. */
162 static time_t server_alive_time; /* Time to do server_alive_check */
164 static void client_init_dispatch(struct ssh *ssh);
165 int session_ident = -1;
167 /* Track escape per proto2 channel */
168 struct escape_filter_ctx {
173 /* Context for channel confirmation replies */
174 struct channel_reply_ctx {
175 const char *request_type;
177 enum confirm_action action;
180 /* Global request success/failure callbacks */
181 /* XXX move to struct ssh? */
182 struct global_confirm {
183 TAILQ_ENTRY(global_confirm) entry;
184 global_confirm_cb *cb;
188 TAILQ_HEAD(global_confirms, global_confirm);
189 static struct global_confirms global_confirms =
190 TAILQ_HEAD_INITIALIZER(global_confirms);
192 void ssh_process_session2_setup(int, int, int, struct sshbuf *);
193 static void quit_message(const char *fmt, ...)
194 __attribute__((__format__ (printf, 1, 2)));
197 quit_message(const char *fmt, ...)
204 xvasprintf(&msg, fmt, args);
207 if ((r = sshbuf_putf(stderr_buffer, "%s\r\n", msg)) != 0)
208 fatal_fr(r, "sshbuf_putf");
213 * Signal handler for the window change signal (SIGWINCH). This just sets a
214 * flag indicating that the window has changed.
218 window_change_handler(int sig)
220 received_window_change_signal = 1;
224 * Signal handler for signals that cause the program to terminate. These
225 * signals must be trapped to restore terminal modes.
229 signal_handler(int sig)
231 received_signal = sig;
236 * Sets control_persist_exit_time to the absolute time when the
237 * backgrounded control master should exit due to expiry of the
238 * ControlPersist timeout. Sets it to 0 if we are not a backgrounded
239 * control master process, or if there is no ControlPersist timeout.
242 set_control_persist_exit_time(struct ssh *ssh)
244 if (muxserver_sock == -1 || !options.control_persist
245 || options.control_persist_timeout == 0) {
246 /* not using a ControlPersist timeout */
247 control_persist_exit_time = 0;
248 } else if (channel_still_open(ssh)) {
249 /* some client connections are still open */
250 if (control_persist_exit_time > 0)
251 debug2_f("cancel scheduled exit");
252 control_persist_exit_time = 0;
253 } else if (control_persist_exit_time <= 0) {
254 /* a client connection has recently closed */
255 control_persist_exit_time = monotime() +
256 (time_t)options.control_persist_timeout;
257 debug2_f("schedule exit in %d seconds",
258 options.control_persist_timeout);
260 /* else we are already counting down to the timeout */
263 #define SSH_X11_VALID_DISPLAY_CHARS ":/.-_"
265 client_x11_display_valid(const char *display)
272 dlen = strlen(display);
273 for (i = 0; i < dlen; i++) {
274 if (!isalnum((u_char)display[i]) &&
275 strchr(SSH_X11_VALID_DISPLAY_CHARS, display[i]) == NULL) {
276 debug("Invalid character '%c' in DISPLAY", display[i]);
283 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
284 #define X11_TIMEOUT_SLACK 60
286 client_x11_get_proto(struct ssh *ssh, const char *display,
287 const char *xauth_path, u_int trusted, u_int timeout,
288 char **_proto, char **_data)
290 char *cmd, line[512], xdisplay[512];
291 char xauthfile[PATH_MAX], xauthdir[PATH_MAX];
292 static char proto[512], data[512];
294 int got_data = 0, generated = 0, do_unlink = 0, r;
296 u_int now, x11_timeout_real;
300 proto[0] = data[0] = xauthfile[0] = xauthdir[0] = '\0';
302 if (!client_x11_display_valid(display)) {
304 logit("DISPLAY \"%s\" invalid; disabling X11 forwarding",
308 if (xauth_path != NULL && stat(xauth_path, &st) == -1) {
309 debug("No xauth program.");
313 if (xauth_path != NULL) {
315 * Handle FamilyLocal case where $DISPLAY does
316 * not match an authorization entry. For this we
317 * just try "xauth list unix:displaynum.screennum".
318 * XXX: "localhost" match to determine FamilyLocal
321 if (strncmp(display, "localhost:", 10) == 0) {
322 if ((r = snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
323 display + 10)) < 0 ||
324 (size_t)r >= sizeof(xdisplay)) {
325 error_f("display name too long");
332 * Generate an untrusted X11 auth cookie.
334 * The authentication cookie should briefly outlive
335 * ssh's willingness to forward X11 connections to
336 * avoid nasty fail-open behaviour in the X server.
338 mktemp_proto(xauthdir, sizeof(xauthdir));
339 if (mkdtemp(xauthdir) == NULL) {
340 error_f("mkdtemp: %s", strerror(errno));
344 if ((r = snprintf(xauthfile, sizeof(xauthfile),
345 "%s/xauthfile", xauthdir)) < 0 ||
346 (size_t)r >= sizeof(xauthfile)) {
347 error_f("xauthfile path too long");
353 /* auth doesn't time out */
354 xasprintf(&cmd, "%s -f %s generate %s %s "
356 xauth_path, xauthfile, display,
357 SSH_X11_PROTO, _PATH_DEVNULL);
359 /* Add some slack to requested expiry */
360 if (timeout < UINT_MAX - X11_TIMEOUT_SLACK)
361 x11_timeout_real = timeout +
364 /* Don't overflow on long timeouts */
365 x11_timeout_real = UINT_MAX;
367 xasprintf(&cmd, "%s -f %s generate %s %s "
368 "untrusted timeout %u 2>%s",
369 xauth_path, xauthfile, display,
370 SSH_X11_PROTO, x11_timeout_real,
373 debug2_f("xauth command: %s", cmd);
375 if (timeout != 0 && x11_refuse_time == 0) {
376 now = monotime() + 1;
377 if (UINT_MAX - timeout < now)
378 x11_refuse_time = UINT_MAX;
380 x11_refuse_time = now + timeout;
381 channel_set_x11_refuse_time(ssh,
384 if (system(cmd) == 0)
390 * When in untrusted mode, we read the cookie only if it was
391 * successfully generated as an untrusted one in the step
394 if (trusted || generated) {
396 "%s %s%s list %s 2>" _PATH_DEVNULL,
398 generated ? "-f " : "" ,
399 generated ? xauthfile : "",
401 debug2("x11_get_proto: %s", cmd);
403 if (f && fgets(line, sizeof(line), f) &&
404 sscanf(line, "%*s %511s %511s", proto, data) == 2)
417 /* Don't fall back to fake X11 data for untrusted forwarding */
418 if (!trusted && !got_data) {
419 error("Warning: untrusted X11 forwarding setup failed: "
420 "xauth key data not generated");
425 * If we didn't get authentication data, just make up some
426 * data. The forwarding code will check the validity of the
427 * response anyway, and substitute this data. The X11
428 * server, however, will ignore this fake data and use
429 * whatever authentication mechanisms it was using otherwise
430 * for the local connection.
436 logit("Warning: No xauth data; "
437 "using fake authentication data for X11 forwarding.");
438 strlcpy(proto, SSH_X11_PROTO, sizeof proto);
439 arc4random_buf(rnd, sizeof(rnd));
440 for (i = 0; i < sizeof(rnd); i++) {
441 snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
450 * Checks if the client window has changed, and sends a packet about it to
451 * the server if so. The actual change is detected elsewhere (by a software
452 * interrupt on Unix); this just checks the flag and sends a message if
457 client_check_window_change(struct ssh *ssh)
459 if (!received_window_change_signal)
461 received_window_change_signal = 0;
463 channel_send_window_changes(ssh);
467 client_global_request_reply(int type, u_int32_t seq, struct ssh *ssh)
469 struct global_confirm *gc;
471 if ((gc = TAILQ_FIRST(&global_confirms)) == NULL)
474 gc->cb(ssh, type, seq, gc->ctx);
475 if (--gc->ref_count <= 0) {
476 TAILQ_REMOVE(&global_confirms, gc, entry);
477 freezero(gc, sizeof(*gc));
480 ssh_packet_set_alive_timeouts(ssh, 0);
485 schedule_server_alive_check(void)
487 if (options.server_alive_interval > 0)
488 server_alive_time = monotime() + options.server_alive_interval;
492 server_alive_check(struct ssh *ssh)
496 if (ssh_packet_inc_alive_timeouts(ssh) > options.server_alive_count_max) {
497 logit("Timeout, server %s not responding.", host);
500 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
501 (r = sshpkt_put_cstring(ssh, "keepalive@openssh.com")) != 0 ||
502 (r = sshpkt_put_u8(ssh, 1)) != 0 || /* boolean: want reply */
503 (r = sshpkt_send(ssh)) != 0)
504 fatal_fr(r, "send packet");
505 /* Insert an empty placeholder to maintain ordering */
506 client_register_global_confirm(NULL, NULL);
507 schedule_server_alive_check();
511 * Waits until the client can do something (some data becomes available on
512 * one of the file descriptors).
515 client_wait_until_can_do_something(struct ssh *ssh, struct pollfd **pfdp,
516 u_int *npfd_allocp, u_int *npfd_activep, int rekeying,
517 int *conn_in_readyp, int *conn_out_readyp)
519 int timeout_secs, pollwait;
520 time_t minwait_secs = 0, now = monotime();
524 *conn_in_readyp = *conn_out_readyp = 0;
526 /* Prepare channel poll. First two pollfd entries are reserved */
527 channel_prepare_poll(ssh, pfdp, npfd_allocp, npfd_activep, 2,
529 if (*npfd_activep < 2)
530 fatal_f("bad npfd %u", *npfd_activep); /* shouldn't happen */
532 /* channel_prepare_poll could have closed the last channel */
533 if (session_closed && !channel_still_open(ssh) &&
534 !ssh_packet_have_data_to_write(ssh)) {
535 /* clear events since we did not call poll() */
536 for (p = 0; p < *npfd_activep; p++)
537 (*pfdp)[p].revents = 0;
541 /* Monitor server connection on reserved pollfd entries */
542 (*pfdp)[0].fd = connection_in;
543 (*pfdp)[0].events = POLLIN;
544 (*pfdp)[1].fd = connection_out;
545 (*pfdp)[1].events = ssh_packet_have_data_to_write(ssh) ? POLLOUT : 0;
548 * Wait for something to happen. This will suspend the process until
549 * some polled descriptor can be read, written, or has some other
550 * event pending, or a timeout expires.
553 timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */
554 if (options.server_alive_interval > 0)
555 timeout_secs = MAXIMUM(server_alive_time - now, 0);
556 if (options.rekey_interval > 0 && !rekeying)
557 timeout_secs = MINIMUM(timeout_secs,
558 ssh_packet_get_rekey_timeout(ssh));
559 set_control_persist_exit_time(ssh);
560 if (control_persist_exit_time > 0) {
561 timeout_secs = MINIMUM(timeout_secs,
562 control_persist_exit_time - now);
563 if (timeout_secs < 0)
566 if (minwait_secs != 0)
567 timeout_secs = MINIMUM(timeout_secs, (int)minwait_secs);
568 if (timeout_secs == INT_MAX)
570 else if (timeout_secs >= INT_MAX / 1000)
573 pollwait = timeout_secs * 1000;
575 ret = poll(*pfdp, *npfd_activep, pollwait);
579 * We have to clear the events because we return.
580 * We have to return, because the mainloop checks for the flags
581 * set by the signal handlers.
583 for (p = 0; p < *npfd_activep; p++)
584 (*pfdp)[p].revents = 0;
587 /* Note: we might still have data in the buffers. */
588 quit_message("poll: %s", strerror(errno));
592 *conn_in_readyp = (*pfdp)[0].revents != 0;
593 *conn_out_readyp = (*pfdp)[1].revents != 0;
595 if (options.server_alive_interval > 0 && !*conn_in_readyp &&
596 monotime() >= server_alive_time) {
598 * ServerAlive check is needed. We can't rely on the poll
599 * timing out since traffic on the client side such as port
600 * forwards can keep waking it up.
602 server_alive_check(ssh);
607 client_suspend_self(struct sshbuf *bin, struct sshbuf *bout, struct sshbuf *berr)
609 /* Flush stdout and stderr buffers. */
610 if (sshbuf_len(bout) > 0)
611 atomicio(vwrite, fileno(stdout), sshbuf_mutable_ptr(bout),
613 if (sshbuf_len(berr) > 0)
614 atomicio(vwrite, fileno(stderr), sshbuf_mutable_ptr(berr),
617 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
623 /* Send the suspend signal to the program itself. */
624 kill(getpid(), SIGTSTP);
626 /* Reset window sizes in case they have changed */
627 received_window_change_signal = 1;
629 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
633 client_process_net_input(struct ssh *ssh)
638 * Read input from the server, and add any such data to the buffer of
639 * the packet subsystem.
641 schedule_server_alive_check();
642 if ((r = ssh_packet_process_read(ssh, connection_in)) == 0)
643 return; /* success */
644 if (r == SSH_ERR_SYSTEM_ERROR) {
645 if (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)
647 if (errno == EPIPE) {
648 quit_message("Connection to %s closed by remote host.",
653 quit_message("Read from remote host %s: %s", host, ssh_err(r));
657 client_status_confirm(struct ssh *ssh, int type, Channel *c, void *ctx)
659 struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx;
664 * If a TTY was explicitly requested, then a failure to allocate
667 if (cr->action == CONFIRM_TTY &&
668 (options.request_tty == REQUEST_TTY_FORCE ||
669 options.request_tty == REQUEST_TTY_YES))
670 cr->action = CONFIRM_CLOSE;
672 /* XXX suppress on mux _client_ quietmode */
673 tochan = options.log_level >= SYSLOG_LEVEL_ERROR &&
674 c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE;
676 if (type == SSH2_MSG_CHANNEL_SUCCESS) {
677 debug2("%s request accepted on channel %d",
678 cr->request_type, c->self);
679 } else if (type == SSH2_MSG_CHANNEL_FAILURE) {
681 snprintf(errmsg, sizeof(errmsg),
682 "%s request failed\r\n", cr->request_type);
684 snprintf(errmsg, sizeof(errmsg),
685 "%s request failed on channel %d",
686 cr->request_type, c->self);
688 /* If error occurred on primary session channel, then exit */
689 if (cr->action == CONFIRM_CLOSE && c->self == session_ident)
692 * If error occurred on mux client, append to
696 debug3_f("channel %d: mux request: %s", c->self,
698 if ((r = sshbuf_put(c->extended, errmsg,
699 strlen(errmsg))) != 0)
700 fatal_fr(r, "sshbuf_put");
703 if (cr->action == CONFIRM_TTY) {
705 * If a TTY allocation error occurred, then arrange
706 * for the correct TTY to leave raw mode.
708 if (c->self == session_ident)
711 mux_tty_alloc_failed(ssh, c);
712 } else if (cr->action == CONFIRM_CLOSE) {
713 chan_read_failed(ssh, c);
714 chan_write_failed(ssh, c);
721 client_abandon_status_confirm(struct ssh *ssh, Channel *c, void *ctx)
727 client_expect_confirm(struct ssh *ssh, int id, const char *request,
728 enum confirm_action action)
730 struct channel_reply_ctx *cr = xcalloc(1, sizeof(*cr));
732 cr->request_type = request;
735 channel_register_status_confirm(ssh, id, client_status_confirm,
736 client_abandon_status_confirm, cr);
740 client_register_global_confirm(global_confirm_cb *cb, void *ctx)
742 struct global_confirm *gc, *last_gc;
744 /* Coalesce identical callbacks */
745 last_gc = TAILQ_LAST(&global_confirms, global_confirms);
746 if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) {
747 if (++last_gc->ref_count >= INT_MAX)
748 fatal_f("last_gc->ref_count = %d",
753 gc = xcalloc(1, sizeof(*gc));
757 TAILQ_INSERT_TAIL(&global_confirms, gc, entry);
761 process_cmdline(struct ssh *ssh)
763 void (*handler)(int);
765 int ok, delete = 0, local = 0, remote = 0, dynamic = 0;
768 memset(&fwd, 0, sizeof(fwd));
770 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
771 handler = ssh_signal(SIGINT, SIG_IGN);
772 cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
775 while (isspace((u_char)*s))
778 s++; /* Skip cmdline '-', if any */
782 if (*s == 'h' || *s == 'H' || *s == '?') {
784 logit(" -L[bind_address:]port:host:hostport "
785 "Request local forward");
786 logit(" -R[bind_address:]port:host:hostport "
787 "Request remote forward");
788 logit(" -D[bind_address:]port "
789 "Request dynamic forward");
790 logit(" -KL[bind_address:]port "
791 "Cancel local forward");
792 logit(" -KR[bind_address:]port "
793 "Cancel remote forward");
794 logit(" -KD[bind_address:]port "
795 "Cancel dynamic forward");
796 if (!options.permit_local_command)
799 "Execute local command");
803 if (*s == '!' && options.permit_local_command) {
820 logit("Invalid command.");
824 while (isspace((u_char)*++s))
827 /* XXX update list of forwards in options */
829 /* We pass 1 for dynamicfwd to restrict to 1 or 2 fields. */
830 if (!parse_forward(&fwd, s, 1, 0)) {
831 logit("Bad forwarding close specification.");
835 ok = channel_request_rforward_cancel(ssh, &fwd) == 0;
837 ok = channel_cancel_lport_listener(ssh, &fwd,
838 0, &options.fwd_opts) > 0;
840 ok = channel_cancel_lport_listener(ssh, &fwd,
841 CHANNEL_CANCEL_PORT_STATIC,
842 &options.fwd_opts) > 0;
844 logit("Unknown port forwarding.");
847 logit("Canceled forwarding.");
849 if (!parse_forward(&fwd, s, dynamic, remote)) {
850 logit("Bad forwarding specification.");
853 if (local || dynamic) {
854 if (!channel_setup_local_fwd_listener(ssh, &fwd,
855 &options.fwd_opts)) {
856 logit("Port forwarding failed.");
860 if (channel_request_remote_forwarding(ssh, &fwd) < 0) {
861 logit("Port forwarding failed.");
865 logit("Forwarding port.");
869 ssh_signal(SIGINT, handler);
870 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
872 free(fwd.listen_host);
873 free(fwd.listen_path);
874 free(fwd.connect_host);
875 free(fwd.connect_path);
878 /* reasons to suppress output of an escape command in help output */
879 #define SUPPRESS_NEVER 0 /* never suppress, always show */
880 #define SUPPRESS_MUXCLIENT 1 /* don't show in mux client sessions */
881 #define SUPPRESS_MUXMASTER 2 /* don't show in mux master sessions */
882 #define SUPPRESS_SYSLOG 4 /* don't show when logging to syslog */
883 struct escape_help_text {
888 static struct escape_help_text esc_txt[] = {
889 {".", "terminate session", SUPPRESS_MUXMASTER},
890 {".", "terminate connection (and any multiplexed sessions)",
892 {"B", "send a BREAK to the remote system", SUPPRESS_NEVER},
893 {"C", "open a command line", SUPPRESS_MUXCLIENT},
894 {"R", "request rekey", SUPPRESS_NEVER},
895 {"V/v", "decrease/increase verbosity (LogLevel)", SUPPRESS_MUXCLIENT},
896 {"^Z", "suspend ssh", SUPPRESS_MUXCLIENT},
897 {"#", "list forwarded connections", SUPPRESS_NEVER},
898 {"&", "background ssh (when waiting for connections to terminate)",
900 {"?", "this message", SUPPRESS_NEVER},
904 print_escape_help(struct sshbuf *b, int escape_char, int mux_client,
907 unsigned int i, suppress_flags;
910 if ((r = sshbuf_putf(b,
911 "%c?\r\nSupported escape sequences:\r\n", escape_char)) != 0)
912 fatal_fr(r, "sshbuf_putf");
915 (mux_client ? SUPPRESS_MUXCLIENT : 0) |
916 (mux_client ? 0 : SUPPRESS_MUXMASTER) |
917 (using_stderr ? 0 : SUPPRESS_SYSLOG);
919 for (i = 0; i < sizeof(esc_txt)/sizeof(esc_txt[0]); i++) {
920 if (esc_txt[i].flags & suppress_flags)
922 if ((r = sshbuf_putf(b, " %c%-3s - %s\r\n",
923 escape_char, esc_txt[i].cmd, esc_txt[i].text)) != 0)
924 fatal_fr(r, "sshbuf_putf");
927 if ((r = sshbuf_putf(b,
928 " %c%c - send the escape character by typing it twice\r\n"
929 "(Note that escapes are only recognized immediately after "
930 "newline.)\r\n", escape_char, escape_char)) != 0)
931 fatal_fr(r, "sshbuf_putf");
935 * Process the characters one by one.
938 process_escapes(struct ssh *ssh, Channel *c,
939 struct sshbuf *bin, struct sshbuf *bout, struct sshbuf *berr,
947 struct escape_filter_ctx *efc = c->filter_ctx == NULL ?
948 NULL : (struct escape_filter_ctx *)c->filter_ctx;
950 if (c->filter_ctx == NULL)
956 for (i = 0; i < (u_int)len; i++) {
957 /* Get one character at a time. */
960 if (efc->escape_pending) {
961 /* We have previously seen an escape character. */
962 /* Clear the flag now. */
963 efc->escape_pending = 0;
965 /* Process the escaped character. */
968 /* Terminate the connection. */
969 if ((r = sshbuf_putf(berr, "%c.\r\n",
970 efc->escape_char)) != 0)
971 fatal_fr(r, "sshbuf_putf");
972 if (c && c->ctl_chan != -1) {
973 chan_read_failed(ssh, c);
974 chan_write_failed(ssh, c);
975 if (c->detach_user) {
979 c->type = SSH_CHANNEL_ABANDONED;
980 sshbuf_reset(c->input);
981 chan_ibuf_empty(ssh, c);
988 /* XXX support this for mux clients */
989 if (c && c->ctl_chan != -1) {
993 snprintf(b, sizeof b, "^Z");
995 snprintf(b, sizeof b, "%c", ch);
996 if ((r = sshbuf_putf(berr,
997 "%c%s escape not available to "
998 "multiplexed sessions\r\n",
999 efc->escape_char, b)) != 0)
1000 fatal_fr(r, "sshbuf_putf");
1003 /* Suspend the program. Inform the user */
1004 if ((r = sshbuf_putf(berr,
1005 "%c^Z [suspend ssh]\r\n",
1006 efc->escape_char)) != 0)
1007 fatal_fr(r, "sshbuf_putf");
1009 /* Restore terminal modes and suspend. */
1010 client_suspend_self(bin, bout, berr);
1012 /* We have been continued. */
1016 if ((r = sshbuf_putf(berr,
1017 "%cB\r\n", efc->escape_char)) != 0)
1018 fatal_fr(r, "sshbuf_putf");
1019 channel_request_start(ssh, c->self, "break", 0);
1020 if ((r = sshpkt_put_u32(ssh, 1000)) != 0 ||
1021 (r = sshpkt_send(ssh)) != 0)
1022 fatal_fr(r, "send packet");
1026 if (ssh->compat & SSH_BUG_NOREKEY)
1027 logit("Server does not "
1028 "support re-keying");
1036 if (c && c->ctl_chan != -1)
1038 if (!log_is_on_stderr()) {
1039 if ((r = sshbuf_putf(berr,
1040 "%c%c [Logging to syslog]\r\n",
1041 efc->escape_char, ch)) != 0)
1042 fatal_fr(r, "sshbuf_putf");
1045 if (ch == 'V' && options.log_level >
1047 log_change_level(--options.log_level);
1048 if (ch == 'v' && options.log_level <
1049 SYSLOG_LEVEL_DEBUG3)
1050 log_change_level(++options.log_level);
1051 if ((r = sshbuf_putf(berr,
1052 "%c%c [LogLevel %s]\r\n",
1053 efc->escape_char, ch,
1054 log_level_name(options.log_level))) != 0)
1055 fatal_fr(r, "sshbuf_putf");
1059 if (c && c->ctl_chan != -1)
1062 * Detach the program (continue to serve
1063 * connections, but put in background and no
1064 * more new connections).
1066 /* Restore tty modes. */
1068 options.request_tty == REQUEST_TTY_FORCE);
1070 /* Stop listening for new connections. */
1071 channel_stop_listening(ssh);
1073 if ((r = sshbuf_putf(berr, "%c& "
1074 "[backgrounded]\n", efc->escape_char)) != 0)
1075 fatal_fr(r, "sshbuf_putf");
1077 /* Fork into background. */
1080 error("fork: %.100s", strerror(errno));
1083 if (pid != 0) { /* This is the parent. */
1084 /* The parent just exits. */
1087 /* The child continues serving connections. */
1088 /* fake EOF on stdin */
1089 if ((r = sshbuf_put_u8(bin, 4)) != 0)
1090 fatal_fr(r, "sshbuf_put_u8");
1093 print_escape_help(berr, efc->escape_char,
1094 (c && c->ctl_chan != -1),
1095 log_is_on_stderr());
1099 if ((r = sshbuf_putf(berr, "%c#\r\n",
1100 efc->escape_char)) != 0)
1101 fatal_fr(r, "sshbuf_putf");
1102 s = channel_open_message(ssh);
1103 if ((r = sshbuf_put(berr, s, strlen(s))) != 0)
1104 fatal_fr(r, "sshbuf_put");
1109 if (c && c->ctl_chan != -1)
1111 process_cmdline(ssh);
1115 if (ch != efc->escape_char) {
1116 if ((r = sshbuf_put_u8(bin,
1117 efc->escape_char)) != 0)
1118 fatal_fr(r, "sshbuf_put_u8");
1121 /* Escaped characters fall through here */
1126 * The previous character was not an escape char.
1127 * Check if this is an escape.
1129 if (last_was_cr && ch == efc->escape_char) {
1131 * It is. Set the flag and continue to
1134 efc->escape_pending = 1;
1140 * Normal character. Record whether it was a newline,
1141 * and append it to the buffer.
1143 last_was_cr = (ch == '\r' || ch == '\n');
1144 if ((r = sshbuf_put_u8(bin, ch)) != 0)
1145 fatal_fr(r, "sshbuf_put_u8");
1152 * Get packets from the connection input buffer, and process them as long as
1153 * there are packets available.
1155 * Any unknown packets received during the actual
1156 * session cause the session to terminate. This is
1157 * intended to make debugging easier since no
1158 * confirmations are sent. Any compatible protocol
1159 * extensions must be negotiated during the
1160 * preparatory phase.
1164 client_process_buffered_input_packets(struct ssh *ssh)
1166 ssh_dispatch_run_fatal(ssh, DISPATCH_NONBLOCK, &quit_pending);
1169 /* scan buf[] for '~' before sending data to the peer */
1171 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */
1173 client_new_escape_filter_ctx(int escape_char)
1175 struct escape_filter_ctx *ret;
1177 ret = xcalloc(1, sizeof(*ret));
1178 ret->escape_pending = 0;
1179 ret->escape_char = escape_char;
1183 /* Free the escape filter context on channel free */
1185 client_filter_cleanup(struct ssh *ssh, int cid, void *ctx)
1191 client_simple_escape_filter(struct ssh *ssh, Channel *c, char *buf, int len)
1193 if (c->extended_usage != CHAN_EXTENDED_WRITE)
1196 return process_escapes(ssh, c, c->input, c->output, c->extended,
1201 client_channel_closed(struct ssh *ssh, int id, void *arg)
1203 channel_cancel_cleanup(ssh, id);
1205 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1209 * Implements the interactive session with the server. This is called after
1210 * the user has been authenticated, and a command has been started on the
1211 * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1212 * used as an escape character for terminating or suspending the session.
1215 client_loop(struct ssh *ssh, int have_pty, int escape_char_arg,
1218 struct pollfd *pfd = NULL;
1219 u_int npfd_alloc = 0, npfd_active = 0;
1220 double start_time, total_time;
1222 u_int64_t ibytes, obytes;
1223 int conn_in_ready, conn_out_ready;
1225 debug("Entering interactive session.");
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",
1232 fatal_f("pledge(): %s", strerror(errno));
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",
1238 fatal_f("pledge(): %s", strerror(errno));
1240 } else if (options.update_hostkeys) {
1241 debug("pledge: filesystem");
1242 if (pledge("stdio rpath wpath cpath unix inet dns proc tty",
1244 fatal_f("pledge(): %s", strerror(errno));
1246 } else if (!option_clear_or_none(options.proxy_command) ||
1247 options.fork_after_authentication) {
1248 debug("pledge: proc");
1249 if (pledge("stdio cpath unix inet dns proc tty", NULL) == -1)
1250 fatal_f("pledge(): %s", strerror(errno));
1253 debug("pledge: network");
1254 if (pledge("stdio unix inet dns proc tty", NULL) == -1)
1255 fatal_f("pledge(): %s", strerror(errno));
1258 start_time = monotime_double();
1260 /* Initialize variables. */
1263 connection_in = ssh_packet_get_connection_in(ssh);
1264 connection_out = ssh_packet_get_connection_out(ssh);
1268 /* Initialize buffer. */
1269 if ((stderr_buffer = sshbuf_new()) == NULL)
1270 fatal_f("sshbuf_new failed");
1272 client_init_dispatch(ssh);
1275 * Set signal handlers, (e.g. to restore non-blocking mode)
1276 * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1278 if (ssh_signal(SIGHUP, SIG_IGN) != SIG_IGN)
1279 ssh_signal(SIGHUP, signal_handler);
1280 if (ssh_signal(SIGINT, SIG_IGN) != SIG_IGN)
1281 ssh_signal(SIGINT, signal_handler);
1282 if (ssh_signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1283 ssh_signal(SIGQUIT, signal_handler);
1284 if (ssh_signal(SIGTERM, SIG_IGN) != SIG_IGN)
1285 ssh_signal(SIGTERM, signal_handler);
1286 ssh_signal(SIGWINCH, window_change_handler);
1289 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1291 session_ident = ssh2_chan_id;
1292 if (session_ident != -1) {
1293 if (escape_char_arg != SSH_ESCAPECHAR_NONE) {
1294 channel_register_filter(ssh, session_ident,
1295 client_simple_escape_filter, NULL,
1296 client_filter_cleanup,
1297 client_new_escape_filter_ctx(
1300 channel_register_cleanup(ssh, session_ident,
1301 client_channel_closed, 0);
1304 schedule_server_alive_check();
1306 /* Main loop of the client for the interactive session mode. */
1307 while (!quit_pending) {
1309 /* Process buffered packets sent by the server. */
1310 client_process_buffered_input_packets(ssh);
1312 if (session_closed && !channel_still_open(ssh))
1315 if (ssh_packet_is_rekeying(ssh)) {
1316 debug("rekeying in progress");
1317 } else if (need_rekeying) {
1318 /* manual rekey request */
1319 debug("need rekeying");
1320 if ((r = kex_start_rekex(ssh)) != 0)
1321 fatal_fr(r, "kex_start_rekex");
1325 * Make packets from buffered channel data, and
1326 * enqueue them for sending to the server.
1328 if (ssh_packet_not_very_much_data_to_write(ssh))
1329 channel_output_poll(ssh);
1332 * Check if the window size has changed, and buffer a
1333 * message about it to the server if so.
1335 client_check_window_change(ssh);
1341 * Wait until we have something to do (something becomes
1342 * available on one of the descriptors).
1344 client_wait_until_can_do_something(ssh, &pfd, &npfd_alloc,
1345 &npfd_active, ssh_packet_is_rekeying(ssh),
1346 &conn_in_ready, &conn_out_ready);
1351 /* Do channel operations unless rekeying in progress. */
1352 if (!ssh_packet_is_rekeying(ssh))
1353 channel_after_poll(ssh, pfd, npfd_active);
1355 /* Buffer input from the connection. */
1357 client_process_net_input(ssh);
1362 /* A timeout may have triggered rekeying */
1363 if ((r = ssh_packet_check_rekey(ssh)) != 0)
1364 fatal_fr(r, "cannot start rekeying");
1367 * Send as much buffered packet data as possible to the
1370 if (conn_out_ready) {
1371 if ((r = ssh_packet_write_poll(ssh)) != 0) {
1372 sshpkt_fatal(ssh, r,
1373 "%s: ssh_packet_write_poll", __func__);
1378 * If we are a backgrounded control master, and the
1379 * timeout has expired without any active client
1380 * connections, then quit.
1382 if (control_persist_exit_time > 0) {
1383 if (monotime() >= control_persist_exit_time) {
1384 debug("ControlPersist timeout expired");
1391 /* Terminate the session. */
1393 /* Stop watching for window change. */
1394 ssh_signal(SIGWINCH, SIG_DFL);
1396 if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
1397 (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_BY_APPLICATION)) != 0 ||
1398 (r = sshpkt_put_cstring(ssh, "disconnected by user")) != 0 ||
1399 (r = sshpkt_put_cstring(ssh, "")) != 0 || /* language tag */
1400 (r = sshpkt_send(ssh)) != 0 ||
1401 (r = ssh_packet_write_wait(ssh)) != 0)
1402 fatal_fr(r, "send disconnect");
1404 channel_free_all(ssh);
1407 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1410 * If there was no shell or command requested, there will be no remote
1411 * exit status to be returned. In that case, clear error code if the
1412 * connection was deliberately terminated at this end.
1414 if (options.session_type == SESSION_TYPE_NONE &&
1415 received_signal == SIGTERM) {
1416 received_signal = 0;
1420 if (received_signal) {
1421 verbose("Killed by signal %d.", (int) received_signal);
1426 * In interactive mode (with pseudo tty) display a message indicating
1427 * that the connection has been closed.
1429 if (have_pty && options.log_level >= SYSLOG_LEVEL_INFO)
1430 quit_message("Connection to %s closed.", host);
1432 /* Output any buffered data for stderr. */
1433 if (sshbuf_len(stderr_buffer) > 0) {
1434 len = atomicio(vwrite, fileno(stderr),
1435 (u_char *)sshbuf_ptr(stderr_buffer),
1436 sshbuf_len(stderr_buffer));
1437 if (len < 0 || (u_int)len != sshbuf_len(stderr_buffer))
1438 error("Write failed flushing stderr buffer.");
1439 else if ((r = sshbuf_consume(stderr_buffer, len)) != 0)
1440 fatal_fr(r, "sshbuf_consume");
1443 /* Clear and free any buffers. */
1444 sshbuf_free(stderr_buffer);
1446 /* Report bytes transferred, and transfer rates. */
1447 total_time = monotime_double() - start_time;
1448 ssh_packet_get_bytes(ssh, &ibytes, &obytes);
1449 verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds",
1450 (unsigned long long)obytes, (unsigned long long)ibytes, total_time);
1452 verbose("Bytes per second: sent %.1f, received %.1f",
1453 obytes / total_time, ibytes / total_time);
1454 /* Return the exit status of the program. */
1455 debug("Exit status %d", exit_status);
1462 client_request_forwarded_tcpip(struct ssh *ssh, const char *request_type,
1463 int rchan, u_int rwindow, u_int rmaxpack)
1466 struct sshbuf *b = NULL;
1467 char *listen_address, *originator_address;
1468 u_int listen_port, originator_port;
1471 /* Get rest of the packet */
1472 if ((r = sshpkt_get_cstring(ssh, &listen_address, NULL)) != 0 ||
1473 (r = sshpkt_get_u32(ssh, &listen_port)) != 0 ||
1474 (r = sshpkt_get_cstring(ssh, &originator_address, NULL)) != 0 ||
1475 (r = sshpkt_get_u32(ssh, &originator_port)) != 0 ||
1476 (r = sshpkt_get_end(ssh)) != 0)
1477 fatal_fr(r, "parse packet");
1479 debug_f("listen %s port %d, originator %s port %d",
1480 listen_address, listen_port, originator_address, originator_port);
1482 if (listen_port > 0xffff)
1483 error_f("invalid listen port");
1484 else if (originator_port > 0xffff)
1485 error_f("invalid originator port");
1487 c = channel_connect_by_listen_address(ssh,
1488 listen_address, listen_port, "forwarded-tcpip",
1489 originator_address);
1492 if (c != NULL && c->type == SSH_CHANNEL_MUX_CLIENT) {
1493 if ((b = sshbuf_new()) == NULL) {
1494 error_f("alloc reply");
1497 /* reconstruct and send to muxclient */
1498 if ((r = sshbuf_put_u8(b, 0)) != 0 || /* padlen */
1499 (r = sshbuf_put_u8(b, SSH2_MSG_CHANNEL_OPEN)) != 0 ||
1500 (r = sshbuf_put_cstring(b, request_type)) != 0 ||
1501 (r = sshbuf_put_u32(b, rchan)) != 0 ||
1502 (r = sshbuf_put_u32(b, rwindow)) != 0 ||
1503 (r = sshbuf_put_u32(b, rmaxpack)) != 0 ||
1504 (r = sshbuf_put_cstring(b, listen_address)) != 0 ||
1505 (r = sshbuf_put_u32(b, listen_port)) != 0 ||
1506 (r = sshbuf_put_cstring(b, originator_address)) != 0 ||
1507 (r = sshbuf_put_u32(b, originator_port)) != 0 ||
1508 (r = sshbuf_put_stringb(c->output, b)) != 0) {
1509 error_fr(r, "compose for muxclient");
1516 free(originator_address);
1517 free(listen_address);
1522 client_request_forwarded_streamlocal(struct ssh *ssh,
1523 const char *request_type, int rchan)
1529 /* Get the remote path. */
1530 if ((r = sshpkt_get_cstring(ssh, &listen_path, NULL)) != 0 ||
1531 (r = sshpkt_get_string(ssh, NULL, NULL)) != 0 || /* reserved */
1532 (r = sshpkt_get_end(ssh)) != 0)
1533 fatal_fr(r, "parse packet");
1535 debug_f("request: %s", listen_path);
1537 c = channel_connect_by_listen_path(ssh, listen_path,
1538 "forwarded-streamlocal@openssh.com", "forwarded-streamlocal");
1544 client_request_x11(struct ssh *ssh, const char *request_type, int rchan)
1548 u_int originator_port;
1551 if (!options.forward_x11) {
1552 error("Warning: ssh server tried X11 forwarding.");
1553 error("Warning: this is probably a break-in attempt by a "
1554 "malicious server.");
1557 if (x11_refuse_time != 0 && (u_int)monotime() >= x11_refuse_time) {
1558 verbose("Rejected X11 connection after ForwardX11Timeout "
1562 if ((r = sshpkt_get_cstring(ssh, &originator, NULL)) != 0 ||
1563 (r = sshpkt_get_u32(ssh, &originator_port)) != 0 ||
1564 (r = sshpkt_get_end(ssh)) != 0)
1565 fatal_fr(r, "parse packet");
1566 /* XXX check permission */
1567 /* XXX range check originator port? */
1568 debug("client_request_x11: request from %s %u", originator,
1571 sock = x11_connect_display(ssh);
1574 c = channel_new(ssh, "x11",
1575 SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1576 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1582 client_request_agent(struct ssh *ssh, const char *request_type, int rchan)
1587 if (!options.forward_agent) {
1588 error("Warning: ssh server tried agent forwarding.");
1589 error("Warning: this is probably a break-in attempt by a "
1590 "malicious server.");
1593 if (forward_agent_sock_path == NULL) {
1594 r = ssh_get_authentication_socket(&sock);
1596 r = ssh_get_authentication_socket_path(forward_agent_sock_path, &sock);
1599 if (r != SSH_ERR_AGENT_NOT_PRESENT)
1600 debug_fr(r, "ssh_get_authentication_socket");
1603 if ((r = ssh_agent_bind_hostkey(sock, ssh->kex->initial_hostkey,
1604 ssh->kex->session_id, ssh->kex->initial_sig, 1)) == 0)
1605 debug_f("bound agent to hostkey");
1607 debug2_fr(r, "ssh_agent_bind_hostkey");
1609 c = channel_new(ssh, "authentication agent connection",
1610 SSH_CHANNEL_OPEN, sock, sock, -1,
1611 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0,
1612 "authentication agent connection", 1);
1618 client_request_tun_fwd(struct ssh *ssh, int tun_mode,
1619 int local_tun, int remote_tun, channel_open_fn *cb, void *cbctx)
1623 char *ifname = NULL;
1625 if (tun_mode == SSH_TUNMODE_NO)
1628 debug("Requesting tun unit %d in mode %d", local_tun, tun_mode);
1630 /* Open local tunnel device */
1631 if ((fd = tun_open(local_tun, tun_mode, &ifname)) == -1) {
1632 error("Tunnel device open failed.");
1635 debug("Tunnel forwarding using interface %s", ifname);
1637 c = channel_new(ssh, "tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1638 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
1641 #if defined(SSH_TUN_FILTER)
1642 if (options.tun_open == SSH_TUNMODE_POINTOPOINT)
1643 channel_register_filter(ssh, c->self, sys_tun_infilter,
1644 sys_tun_outfilter, NULL, NULL);
1648 channel_register_open_confirm(ssh, c->self, cb, cbctx);
1650 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN)) != 0 ||
1651 (r = sshpkt_put_cstring(ssh, "tun@openssh.com")) != 0 ||
1652 (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
1653 (r = sshpkt_put_u32(ssh, c->local_window_max)) != 0 ||
1654 (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 ||
1655 (r = sshpkt_put_u32(ssh, tun_mode)) != 0 ||
1656 (r = sshpkt_put_u32(ssh, remote_tun)) != 0 ||
1657 (r = sshpkt_send(ssh)) != 0)
1658 sshpkt_fatal(ssh, r, "%s: send reply", __func__);
1663 /* XXXX move to generic input handler */
1665 client_input_channel_open(int type, u_int32_t seq, struct ssh *ssh)
1672 u_int rmaxpack, rwindow;
1674 if ((r = sshpkt_get_cstring(ssh, &ctype, &len)) != 0 ||
1675 (r = sshpkt_get_u32(ssh, &rchan)) != 0 ||
1676 (r = sshpkt_get_u32(ssh, &rwindow)) != 0 ||
1677 (r = sshpkt_get_u32(ssh, &rmaxpack)) != 0)
1680 debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1681 ctype, rchan, rwindow, rmaxpack);
1683 if (strcmp(ctype, "forwarded-tcpip") == 0) {
1684 c = client_request_forwarded_tcpip(ssh, ctype, rchan, rwindow,
1686 } else if (strcmp(ctype, "forwarded-streamlocal@openssh.com") == 0) {
1687 c = client_request_forwarded_streamlocal(ssh, ctype, rchan);
1688 } else if (strcmp(ctype, "x11") == 0) {
1689 c = client_request_x11(ssh, ctype, rchan);
1690 } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1691 c = client_request_agent(ssh, ctype, rchan);
1693 if (c != NULL && c->type == SSH_CHANNEL_MUX_CLIENT) {
1694 debug3("proxied to downstream: %s", ctype);
1695 } else if (c != NULL) {
1696 debug("confirm %s", ctype);
1697 c->remote_id = rchan;
1698 c->have_remote_id = 1;
1699 c->remote_window = rwindow;
1700 c->remote_maxpacket = rmaxpack;
1701 if (c->type != SSH_CHANNEL_CONNECTING) {
1702 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 ||
1703 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
1704 (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
1705 (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
1706 (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 ||
1707 (r = sshpkt_send(ssh)) != 0)
1708 sshpkt_fatal(ssh, r, "%s: send reply", __func__);
1711 debug("failure %s", ctype);
1712 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE)) != 0 ||
1713 (r = sshpkt_put_u32(ssh, rchan)) != 0 ||
1714 (r = sshpkt_put_u32(ssh, SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED)) != 0 ||
1715 (r = sshpkt_put_cstring(ssh, "open failed")) != 0 ||
1716 (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1717 (r = sshpkt_send(ssh)) != 0)
1718 sshpkt_fatal(ssh, r, "%s: send failure", __func__);
1727 client_input_channel_req(int type, u_int32_t seq, struct ssh *ssh)
1735 if ((r = sshpkt_get_u32(ssh, &id)) != 0)
1738 c = channel_lookup(ssh, id);
1739 if (channel_proxy_upstream(c, type, seq, ssh))
1741 if ((r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 ||
1742 (r = sshpkt_get_u8(ssh, &reply)) != 0)
1745 debug("client_input_channel_req: channel %u rtype %s reply %d",
1749 error("client_input_channel_req: channel %d: "
1750 "unknown channel", id);
1751 } else if (strcmp(rtype, "eow@openssh.com") == 0) {
1752 if ((r = sshpkt_get_end(ssh)) != 0)
1754 chan_rcvd_eow(ssh, c);
1755 } else if (strcmp(rtype, "exit-status") == 0) {
1756 if ((r = sshpkt_get_u32(ssh, &exitval)) != 0)
1758 if (c->ctl_chan != -1) {
1759 mux_exit_message(ssh, c, exitval);
1761 } else if ((int)id == session_ident) {
1762 /* Record exit value of local session */
1764 exit_status = exitval;
1766 /* Probably for a mux channel that has already closed */
1767 debug_f("no sink for exit-status on channel %d",
1770 if ((r = sshpkt_get_end(ssh)) != 0)
1773 if (reply && c != NULL && !(c->flags & CHAN_CLOSE_SENT)) {
1774 if (!c->have_remote_id)
1775 fatal_f("channel %d: no remote_id", c->self);
1776 if ((r = sshpkt_start(ssh, success ?
1777 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE)) != 0 ||
1778 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
1779 (r = sshpkt_send(ssh)) != 0)
1780 sshpkt_fatal(ssh, r, "%s: send failure", __func__);
1788 struct hostkeys_update_ctx {
1789 /* The hostname and (optionally) IP address string for the server */
1790 char *host_str, *ip_str;
1793 * Keys received from the server and a flag for each indicating
1794 * whether they already exist in known_hosts.
1795 * keys_match is filled in by hostkeys_find() and later (for new
1796 * keys) by client_global_hostkeys_private_confirm().
1798 struct sshkey **keys;
1799 u_int *keys_match; /* mask of HKF_MATCH_* from hostfile.h */
1800 int *keys_verified; /* flag for new keys verified by server */
1801 size_t nkeys, nnew, nincomplete; /* total, new keys, incomplete match */
1804 * Keys that are in known_hosts, but were not present in the update
1805 * from the server (i.e. scheduled to be deleted).
1806 * Filled in by hostkeys_find().
1808 struct sshkey **old_keys;
1811 /* Various special cases. */
1812 int complex_hostspec; /* wildcard or manual pattern-list host name */
1813 int ca_available; /* saw CA key for this host */
1814 int old_key_seen; /* saw old key with other name/addr */
1815 int other_name_seen; /* saw key with other name/addr */
1819 hostkeys_update_ctx_free(struct hostkeys_update_ctx *ctx)
1825 for (i = 0; i < ctx->nkeys; i++)
1826 sshkey_free(ctx->keys[i]);
1828 free(ctx->keys_match);
1829 free(ctx->keys_verified);
1830 for (i = 0; i < ctx->nold; i++)
1831 sshkey_free(ctx->old_keys[i]);
1832 free(ctx->old_keys);
1833 free(ctx->host_str);
1839 * Returns non-zero if a known_hosts hostname list is not of a form that
1840 * can be handled by UpdateHostkeys. These include wildcard hostnames and
1841 * hostnames lists that do not follow the form host[,ip].
1844 hostspec_is_complex(const char *hosts)
1849 if (strchr(hosts, '*') != NULL || strchr(hosts, '?') != NULL)
1851 /* single host/ip = ok */
1852 if ((cp = strchr(hosts, ',')) == NULL)
1854 /* more than two entries on the line */
1855 if (strchr(cp + 1, ',') != NULL)
1857 /* XXX maybe parse cp+1 and ensure it is an IP? */
1861 /* callback to search for ctx->keys in known_hosts */
1863 hostkeys_find(struct hostkey_foreach_line *l, void *_ctx)
1865 struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx;
1867 struct sshkey **tmp;
1871 if (l->status != HKF_STATUS_MATCHED) {
1872 /* Record if one of the keys appears on a non-matching line */
1873 for (i = 0; i < ctx->nkeys; i++) {
1874 if (sshkey_equal(l->key, ctx->keys[i])) {
1875 ctx->other_name_seen = 1;
1876 debug3_f("found %s key under different "
1877 "name/addr at %s:%ld",
1878 sshkey_ssh_name(ctx->keys[i]),
1879 l->path, l->linenum);
1885 /* Don't proceed if revocation or CA markers are present */
1886 /* XXX relax this */
1887 if (l->marker != MRK_NONE) {
1888 debug3_f("hostkeys file %s:%ld has CA/revocation marker",
1889 l->path, l->linenum);
1890 ctx->complex_hostspec = 1;
1894 /* If CheckHostIP is enabled, then check for mismatched hostname/addr */
1895 if (ctx->ip_str != NULL && strchr(l->hosts, ',') != NULL) {
1896 if ((l->match & HKF_MATCH_HOST) == 0) {
1897 /* Record if address matched a different hostname. */
1898 ctx->other_name_seen = 1;
1899 debug3_f("found address %s against different hostname "
1900 "at %s:%ld", ctx->ip_str, l->path, l->linenum);
1902 } else if ((l->match & HKF_MATCH_IP) == 0) {
1903 /* Record if hostname matched a different address. */
1904 ctx->other_name_seen = 1;
1905 debug3_f("found hostname %s against different address "
1906 "at %s:%ld", ctx->host_str, l->path, l->linenum);
1911 * UpdateHostkeys is skipped for wildcard host names and hostnames
1912 * that contain more than two entries (ssh never writes these).
1914 if (hostspec_is_complex(l->hosts)) {
1915 debug3_f("hostkeys file %s:%ld complex host specification",
1916 l->path, l->linenum);
1917 ctx->complex_hostspec = 1;
1921 /* Mark off keys we've already seen for this host */
1922 for (i = 0; i < ctx->nkeys; i++) {
1923 if (!sshkey_equal(l->key, ctx->keys[i]))
1925 debug3_f("found %s key at %s:%ld",
1926 sshkey_ssh_name(ctx->keys[i]), l->path, l->linenum);
1927 ctx->keys_match[i] |= l->match;
1930 /* This line contained a key that not offered by the server */
1931 debug3_f("deprecated %s key at %s:%ld", sshkey_ssh_name(l->key),
1932 l->path, l->linenum);
1933 if ((tmp = recallocarray(ctx->old_keys, ctx->nold, ctx->nold + 1,
1934 sizeof(*ctx->old_keys))) == NULL)
1935 fatal_f("recallocarray failed nold = %zu", ctx->nold);
1936 ctx->old_keys = tmp;
1937 ctx->old_keys[ctx->nold++] = l->key;
1943 /* callback to search for ctx->old_keys in known_hosts under other names */
1945 hostkeys_check_old(struct hostkey_foreach_line *l, void *_ctx)
1947 struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx;
1951 /* only care about lines that *don't* match the active host spec */
1952 if (l->status == HKF_STATUS_MATCHED || l->key == NULL)
1955 hashed = l->match & (HKF_MATCH_HOST_HASHED|HKF_MATCH_IP_HASHED);
1956 for (i = 0; i < ctx->nold; i++) {
1957 if (!sshkey_equal(l->key, ctx->old_keys[i]))
1959 debug3_f("found deprecated %s key at %s:%ld as %s",
1960 sshkey_ssh_name(ctx->old_keys[i]), l->path, l->linenum,
1961 hashed ? "[HASHED]" : l->hosts);
1962 ctx->old_key_seen = 1;
1969 * Check known_hosts files for deprecated keys under other names. Returns 0
1970 * on success or -1 on failure. Updates ctx->old_key_seen if deprecated keys
1971 * exist under names other than the active hostname/IP.
1974 check_old_keys_othernames(struct hostkeys_update_ctx *ctx)
1979 debug2_f("checking for %zu deprecated keys", ctx->nold);
1980 for (i = 0; i < options.num_user_hostfiles; i++) {
1981 debug3_f("searching %s for %s / %s",
1982 options.user_hostfiles[i], ctx->host_str,
1983 ctx->ip_str ? ctx->ip_str : "(none)");
1984 if ((r = hostkeys_foreach(options.user_hostfiles[i],
1985 hostkeys_check_old, ctx, ctx->host_str, ctx->ip_str,
1986 HKF_WANT_PARSE_KEY, 0)) != 0) {
1987 if (r == SSH_ERR_SYSTEM_ERROR && errno == ENOENT) {
1988 debug_f("hostkeys file %s does not exist",
1989 options.user_hostfiles[i]);
1992 error_fr(r, "hostkeys_foreach failed for %s",
1993 options.user_hostfiles[i]);
2001 hostkey_change_preamble(LogLevel loglevel)
2003 do_log2(loglevel, "The server has updated its host keys.");
2004 do_log2(loglevel, "These changes were verified by the server's "
2005 "existing trusted key.");
2009 update_known_hosts(struct hostkeys_update_ctx *ctx)
2011 int r, was_raw = 0, first = 1;
2012 int asking = options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK;
2013 LogLevel loglevel = asking ? SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_VERBOSE;
2014 char *fp, *response;
2018 for (i = 0; i < ctx->nkeys; i++) {
2019 if (!ctx->keys_verified[i])
2021 if ((fp = sshkey_fingerprint(ctx->keys[i],
2022 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
2023 fatal_f("sshkey_fingerprint failed");
2024 if (first && asking)
2025 hostkey_change_preamble(loglevel);
2026 do_log2(loglevel, "Learned new hostkey: %s %s",
2027 sshkey_type(ctx->keys[i]), fp);
2031 for (i = 0; i < ctx->nold; i++) {
2032 if ((fp = sshkey_fingerprint(ctx->old_keys[i],
2033 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
2034 fatal_f("sshkey_fingerprint failed");
2035 if (first && asking)
2036 hostkey_change_preamble(loglevel);
2037 do_log2(loglevel, "Deprecating obsolete hostkey: %s %s",
2038 sshkey_type(ctx->old_keys[i]), fp);
2042 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) {
2043 if (get_saved_tio() != NULL) {
2048 for (i = 0; !quit_pending && i < 3; i++) {
2050 response = read_passphrase("Accept updated hostkeys? "
2051 "(yes/no): ", RP_ECHO);
2052 if (strcasecmp(response, "yes") == 0)
2054 else if (quit_pending || response == NULL ||
2055 strcasecmp(response, "no") == 0) {
2056 options.update_hostkeys = 0;
2059 do_log2(loglevel, "Please enter "
2060 "\"yes\" or \"no\"");
2063 if (quit_pending || i >= 3 || response == NULL)
2064 options.update_hostkeys = 0;
2069 if (options.update_hostkeys == 0)
2072 * Now that all the keys are verified, we can go ahead and replace
2073 * them in known_hosts (assuming SSH_UPDATE_HOSTKEYS_ASK didn't
2074 * cancel the operation).
2076 for (i = 0; i < options.num_user_hostfiles; i++) {
2078 * NB. keys are only added to hostfiles[0], for the rest we
2079 * just delete the hostname entries.
2081 if (stat(options.user_hostfiles[i], &sb) != 0) {
2082 if (errno == ENOENT) {
2083 debug_f("known hosts file %s does not "
2084 "exist", options.user_hostfiles[i]);
2086 error_f("known hosts file %s "
2088 options.user_hostfiles[i], strerror(errno));
2092 if ((r = hostfile_replace_entries(options.user_hostfiles[i],
2093 ctx->host_str, ctx->ip_str,
2094 i == 0 ? ctx->keys : NULL, i == 0 ? ctx->nkeys : 0,
2095 options.hash_known_hosts, 0,
2096 options.fingerprint_hash)) != 0) {
2097 error_fr(r, "hostfile_replace_entries failed for %s",
2098 options.user_hostfiles[i]);
2104 client_global_hostkeys_private_confirm(struct ssh *ssh, int type,
2105 u_int32_t seq, void *_ctx)
2107 struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx;
2109 struct sshbuf *signdata;
2112 const char *rsa_kexalg = NULL;
2117 fatal_f("ctx->nnew == 0"); /* sanity */
2118 if (type != SSH2_MSG_REQUEST_SUCCESS) {
2119 error("Server failed to confirm ownership of "
2120 "private host keys");
2121 hostkeys_update_ctx_free(ctx);
2124 if (sshkey_type_plain(sshkey_type_from_name(
2125 ssh->kex->hostkey_alg)) == KEY_RSA)
2126 rsa_kexalg = ssh->kex->hostkey_alg;
2127 if ((signdata = sshbuf_new()) == NULL)
2128 fatal_f("sshbuf_new failed");
2130 * Expect a signature for each of the ctx->nnew private keys we
2131 * haven't seen before. They will be in the same order as the
2132 * ctx->keys where the corresponding ctx->keys_match[i] == 0.
2134 for (ndone = i = 0; i < ctx->nkeys; i++) {
2135 if (ctx->keys_match[i])
2137 plaintype = sshkey_type_plain(ctx->keys[i]->type);
2138 /* Prepare data to be signed: session ID, unique string, key */
2139 sshbuf_reset(signdata);
2140 if ( (r = sshbuf_put_cstring(signdata,
2141 "hostkeys-prove-00@openssh.com")) != 0 ||
2142 (r = sshbuf_put_stringb(signdata,
2143 ssh->kex->session_id)) != 0 ||
2144 (r = sshkey_puts(ctx->keys[i], signdata)) != 0)
2145 fatal_fr(r, "compose signdata");
2146 /* Extract and verify signature */
2147 if ((r = sshpkt_get_string_direct(ssh, &sig, &siglen)) != 0) {
2148 error_fr(r, "parse sig");
2151 if ((r = sshkey_get_sigtype(sig, siglen, &alg)) != 0) {
2152 error_fr(r, "server gave unintelligible signature "
2153 "for %s key %zu", sshkey_type(ctx->keys[i]), i);
2157 * Special case for RSA keys: if a RSA hostkey was negotiated,
2158 * then use its signature type for verification of RSA hostkey
2159 * proofs. Otherwise, accept only RSA-SHA256/512 signatures.
2161 if (plaintype == KEY_RSA && rsa_kexalg == NULL &&
2162 match_pattern_list(alg, HOSTKEY_PROOF_RSA_ALGS, 0) != 1) {
2163 debug_f("server used untrusted RSA signature algorithm "
2164 "%s for key %zu, disregarding", alg, i);
2166 /* zap the key from the list */
2167 sshkey_free(ctx->keys[i]);
2168 ctx->keys[i] = NULL;
2172 debug3_f("verify %s key %zu using sigalg %s",
2173 sshkey_type(ctx->keys[i]), i, alg);
2175 if ((r = sshkey_verify(ctx->keys[i], sig, siglen,
2176 sshbuf_ptr(signdata), sshbuf_len(signdata),
2177 plaintype == KEY_RSA ? rsa_kexalg : NULL, 0, NULL)) != 0) {
2178 error_fr(r, "server gave bad signature for %s key %zu",
2179 sshkey_type(ctx->keys[i]), i);
2182 /* Key is good. Mark it as 'seen' */
2183 ctx->keys_verified[i] = 1;
2186 /* Shouldn't happen */
2187 if (ndone != ctx->nnew)
2188 fatal_f("ndone != ctx->nnew (%zu / %zu)", ndone, ctx->nnew);
2189 if ((r = sshpkt_get_end(ssh)) != 0) {
2190 error_f("protocol error");
2194 /* Make the edits to known_hosts */
2195 update_known_hosts(ctx);
2197 hostkeys_update_ctx_free(ctx);
2201 * Returns non-zero if the key is accepted by HostkeyAlgorithms.
2202 * Made slightly less trivial by the multiple RSA signature algorithm names.
2205 key_accepted_by_hostkeyalgs(const struct sshkey *key)
2207 const char *ktype = sshkey_ssh_name(key);
2208 const char *hostkeyalgs = options.hostkeyalgorithms;
2210 if (key == NULL || key->type == KEY_UNSPEC)
2212 if (key->type == KEY_RSA &&
2213 (match_pattern_list("rsa-sha2-256", hostkeyalgs, 0) == 1 ||
2214 match_pattern_list("rsa-sha2-512", hostkeyalgs, 0) == 1))
2216 return match_pattern_list(ktype, hostkeyalgs, 0) == 1;
2220 * Handle hostkeys-00@openssh.com global request to inform the client of all
2221 * the server's hostkeys. The keys are checked against the user's
2222 * HostkeyAlgorithms preference before they are accepted.
2225 client_input_hostkeys(struct ssh *ssh)
2227 const u_char *blob = NULL;
2229 struct sshbuf *buf = NULL;
2230 struct sshkey *key = NULL, **tmp;
2233 static int hostkeys_seen = 0; /* XXX use struct ssh */
2234 extern struct sockaddr_storage hostaddr; /* XXX from ssh.c */
2235 struct hostkeys_update_ctx *ctx = NULL;
2239 fatal_f("server already sent hostkeys");
2240 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK &&
2242 return 1; /* won't ask in batchmode, so don't even try */
2243 if (!options.update_hostkeys || options.num_user_hostfiles <= 0)
2246 ctx = xcalloc(1, sizeof(*ctx));
2247 while (ssh_packet_remaining(ssh) > 0) {
2250 if ((r = sshpkt_get_string_direct(ssh, &blob, &len)) != 0) {
2251 error_fr(r, "parse key");
2254 if ((r = sshkey_from_blob(blob, len, &key)) != 0) {
2255 do_log2_fr(r, r == SSH_ERR_KEY_TYPE_UNKNOWN ?
2256 SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_ERROR,
2260 fp = sshkey_fingerprint(key, options.fingerprint_hash,
2262 debug3_f("received %s key %s", sshkey_type(key), fp);
2265 if (!key_accepted_by_hostkeyalgs(key)) {
2266 debug3_f("%s key not permitted by "
2267 "HostkeyAlgorithms", sshkey_ssh_name(key));
2271 if (sshkey_is_cert(key)) {
2272 debug3_f("%s key is a certificate; skipping",
2273 sshkey_ssh_name(key));
2276 /* Ensure keys are unique */
2277 for (i = 0; i < ctx->nkeys; i++) {
2278 if (sshkey_equal(key, ctx->keys[i])) {
2279 error_f("received duplicated %s host key",
2280 sshkey_ssh_name(key));
2284 /* Key is good, record it */
2285 if ((tmp = recallocarray(ctx->keys, ctx->nkeys, ctx->nkeys + 1,
2286 sizeof(*ctx->keys))) == NULL)
2287 fatal_f("recallocarray failed nkeys = %zu",
2290 ctx->keys[ctx->nkeys++] = key;
2294 if (ctx->nkeys == 0) {
2295 debug_f("server sent no hostkeys");
2299 if ((ctx->keys_match = calloc(ctx->nkeys,
2300 sizeof(*ctx->keys_match))) == NULL ||
2301 (ctx->keys_verified = calloc(ctx->nkeys,
2302 sizeof(*ctx->keys_verified))) == NULL)
2303 fatal_f("calloc failed");
2305 get_hostfile_hostname_ipaddr(host,
2306 options.check_host_ip ? (struct sockaddr *)&hostaddr : NULL,
2307 options.port, &ctx->host_str,
2308 options.check_host_ip ? &ctx->ip_str : NULL);
2310 /* Find which keys we already know about. */
2311 for (i = 0; i < options.num_user_hostfiles; i++) {
2312 debug_f("searching %s for %s / %s",
2313 options.user_hostfiles[i], ctx->host_str,
2314 ctx->ip_str ? ctx->ip_str : "(none)");
2315 if ((r = hostkeys_foreach(options.user_hostfiles[i],
2316 hostkeys_find, ctx, ctx->host_str, ctx->ip_str,
2317 HKF_WANT_PARSE_KEY, 0)) != 0) {
2318 if (r == SSH_ERR_SYSTEM_ERROR && errno == ENOENT) {
2319 debug_f("hostkeys file %s does not exist",
2320 options.user_hostfiles[i]);
2323 error_fr(r, "hostkeys_foreach failed for %s",
2324 options.user_hostfiles[i]);
2329 /* Figure out if we have any new keys to add */
2330 ctx->nnew = ctx->nincomplete = 0;
2331 want = HKF_MATCH_HOST | ( options.check_host_ip ? HKF_MATCH_IP : 0);
2332 for (i = 0; i < ctx->nkeys; i++) {
2333 if (ctx->keys_match[i] == 0)
2335 if ((ctx->keys_match[i] & want) != want)
2339 debug3_f("%zu server keys: %zu new, %zu retained, "
2340 "%zu incomplete match. %zu to remove", ctx->nkeys, ctx->nnew,
2341 ctx->nkeys - ctx->nnew - ctx->nincomplete,
2342 ctx->nincomplete, ctx->nold);
2344 if (ctx->nnew == 0 && ctx->nold == 0) {
2345 debug_f("no new or deprecated keys from server");
2349 /* Various reasons why we cannot proceed with the update */
2350 if (ctx->complex_hostspec) {
2351 debug_f("CA/revocation marker, manual host list or wildcard "
2352 "host pattern found, skipping UserKnownHostsFile update");
2355 if (ctx->other_name_seen) {
2356 debug_f("host key found matching a different name/address, "
2357 "skipping UserKnownHostsFile update");
2361 * If removing keys, check whether they appear under different
2362 * names/addresses and refuse to proceed if they do. This avoids
2363 * cases such as hosts with multiple names becoming inconsistent
2364 * with regards to CheckHostIP entries.
2365 * XXX UpdateHostkeys=force to override this (and other) checks?
2367 if (ctx->nold != 0) {
2368 if (check_old_keys_othernames(ctx) != 0)
2369 goto out; /* error already logged */
2370 if (ctx->old_key_seen) {
2371 debug_f("key(s) for %s%s%s exist under other names; "
2372 "skipping UserKnownHostsFile update",
2373 ctx->host_str, ctx->ip_str == NULL ? "" : ",",
2374 ctx->ip_str == NULL ? "" : ctx->ip_str);
2379 if (ctx->nnew == 0) {
2381 * We have some keys to remove or fix matching for.
2382 * We can proceed to do this without requiring a fresh proof
2385 update_known_hosts(ctx);
2389 * We have received previously-unseen keys from the server.
2390 * Ask the server to confirm ownership of the private halves.
2392 debug3_f("asking server to prove ownership for %zu keys", ctx->nnew);
2393 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
2394 (r = sshpkt_put_cstring(ssh,
2395 "hostkeys-prove-00@openssh.com")) != 0 ||
2396 (r = sshpkt_put_u8(ssh, 1)) != 0) /* bool: want reply */
2397 fatal_fr(r, "prepare hostkeys-prove");
2398 if ((buf = sshbuf_new()) == NULL)
2399 fatal_f("sshbuf_new");
2400 for (i = 0; i < ctx->nkeys; i++) {
2401 if (ctx->keys_match[i])
2404 if ((r = sshkey_putb(ctx->keys[i], buf)) != 0 ||
2405 (r = sshpkt_put_stringb(ssh, buf)) != 0)
2406 fatal_fr(r, "assemble hostkeys-prove");
2408 if ((r = sshpkt_send(ssh)) != 0)
2409 fatal_fr(r, "send hostkeys-prove");
2410 client_register_global_confirm(
2411 client_global_hostkeys_private_confirm, ctx);
2412 ctx = NULL; /* will be freed in callback */
2416 hostkeys_update_ctx_free(ctx);
2420 * NB. Return success for all cases. The server doesn't need to know
2421 * what the client does with its hosts file.
2427 client_input_global_request(int type, u_int32_t seq, struct ssh *ssh)
2433 if ((r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 ||
2434 (r = sshpkt_get_u8(ssh, &want_reply)) != 0)
2436 debug("client_input_global_request: rtype %s want_reply %d",
2438 if (strcmp(rtype, "hostkeys-00@openssh.com") == 0)
2439 success = client_input_hostkeys(ssh);
2441 if ((r = sshpkt_start(ssh, success ? SSH2_MSG_REQUEST_SUCCESS :
2442 SSH2_MSG_REQUEST_FAILURE)) != 0 ||
2443 (r = sshpkt_send(ssh)) != 0 ||
2444 (r = ssh_packet_write_wait(ssh)) != 0)
2454 client_send_env(struct ssh *ssh, int id, const char *name, const char *val)
2458 debug("channel %d: setting env %s = \"%s\"", id, name, val);
2459 channel_request_start(ssh, id, "env", 0);
2460 if ((r = sshpkt_put_cstring(ssh, name)) != 0 ||
2461 (r = sshpkt_put_cstring(ssh, val)) != 0 ||
2462 (r = sshpkt_send(ssh)) != 0)
2463 fatal_fr(r, "send setenv");
2467 client_session2_setup(struct ssh *ssh, int id, int want_tty, int want_subsystem,
2468 const char *term, struct termios *tiop, int in_fd, struct sshbuf *cmd,
2471 int i, j, matched, len, r;
2475 debug2_f("id %d", id);
2477 if ((c = channel_lookup(ssh, id)) == NULL)
2478 fatal_f("channel %d: unknown channel", id);
2480 ssh_packet_set_interactive(ssh, want_tty,
2481 options.ip_qos_interactive, options.ip_qos_bulk);
2486 /* Store window size in the packet. */
2487 if (ioctl(in_fd, TIOCGWINSZ, &ws) == -1)
2488 memset(&ws, 0, sizeof(ws));
2490 channel_request_start(ssh, id, "pty-req", 1);
2491 client_expect_confirm(ssh, id, "PTY allocation", CONFIRM_TTY);
2492 if ((r = sshpkt_put_cstring(ssh, term != NULL ? term : ""))
2494 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_col)) != 0 ||
2495 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_row)) != 0 ||
2496 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_xpixel)) != 0 ||
2497 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_ypixel)) != 0)
2498 fatal_fr(r, "build pty-req");
2500 tiop = get_saved_tio();
2501 ssh_tty_make_modes(ssh, -1, tiop);
2502 if ((r = sshpkt_send(ssh)) != 0)
2503 fatal_fr(r, "send pty-req");
2504 /* XXX wait for reply */
2508 /* Transfer any environment variables from client to server */
2509 if (options.num_send_env != 0 && env != NULL) {
2510 debug("Sending environment.");
2511 for (i = 0; env[i] != NULL; i++) {
2513 name = xstrdup(env[i]);
2514 if ((val = strchr(name, '=')) == NULL) {
2521 for (j = 0; j < options.num_send_env; j++) {
2522 if (match_pattern(name, options.send_env[j])) {
2528 debug3("Ignored env %s", name);
2532 client_send_env(ssh, id, name, val);
2536 for (i = 0; i < options.num_setenv; i++) {
2538 name = xstrdup(options.setenv[i]);
2539 if ((val = strchr(name, '=')) == NULL) {
2544 client_send_env(ssh, id, name, val);
2548 len = sshbuf_len(cmd);
2552 if (want_subsystem) {
2553 debug("Sending subsystem: %.*s",
2554 len, (const u_char*)sshbuf_ptr(cmd));
2555 channel_request_start(ssh, id, "subsystem", 1);
2556 client_expect_confirm(ssh, id, "subsystem",
2559 debug("Sending command: %.*s",
2560 len, (const u_char*)sshbuf_ptr(cmd));
2561 channel_request_start(ssh, id, "exec", 1);
2562 client_expect_confirm(ssh, id, "exec", CONFIRM_CLOSE);
2564 if ((r = sshpkt_put_stringb(ssh, cmd)) != 0 ||
2565 (r = sshpkt_send(ssh)) != 0)
2566 fatal_fr(r, "send command");
2568 channel_request_start(ssh, id, "shell", 1);
2569 client_expect_confirm(ssh, id, "shell", CONFIRM_CLOSE);
2570 if ((r = sshpkt_send(ssh)) != 0)
2571 fatal_fr(r, "send shell");
2576 client_init_dispatch(struct ssh *ssh)
2578 ssh_dispatch_init(ssh, &dispatch_protocol_error);
2580 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
2581 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_DATA, &channel_input_data);
2582 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
2583 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
2584 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
2585 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2586 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2587 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
2588 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
2589 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm);
2590 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm);
2591 ssh_dispatch_set(ssh, SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
2594 ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, &kex_input_kexinit);
2596 /* global request reply messages */
2597 ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
2598 ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
2602 client_stop_mux(void)
2604 if (options.control_path != NULL && muxserver_sock != -1)
2605 unlink(options.control_path);
2607 * If we are in persist mode, or don't have a shell, signal that we
2608 * should close when all active channels are closed.
2610 if (options.control_persist || options.session_type == SESSION_TYPE_NONE) {
2612 setproctitle("[stopped mux]");
2616 /* client specific fatal cleanup */
2620 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
2621 if (options.control_path != NULL && muxserver_sock != -1)
2622 unlink(options.control_path);
2623 ssh_kill_proxy_command();