Annotation of src/usr.bin/ssh/clientloop.c, Revision 1.343
1.343 ! djm 1: /* $OpenBSD: clientloop.c,v 1.342 2020/02/26 13:40:09 jsg Exp $ */
1.1 deraadt 2: /*
1.12 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.33 deraadt 6: * The main loop for the interactive session (client side).
1.20 markus 7: *
1.33 deraadt 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.
1.20 markus 36: *
37: *
1.33 deraadt 38: * SSH2 support added by Markus Friedl.
1.78 markus 39: * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved.
1.20 markus 40: *
1.33 deraadt 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.
1.12 deraadt 60: */
1.1 deraadt 61:
1.152 stevesk 62:
1.175 deraadt 63: #include <sys/types.h>
1.152 stevesk 64: #include <sys/ioctl.h>
1.154 stevesk 65: #include <sys/stat.h>
1.166 stevesk 66: #include <sys/socket.h>
1.171 stevesk 67: #include <sys/time.h>
1.189 djm 68: #include <sys/queue.h>
1.150 stevesk 69:
1.155 stevesk 70: #include <ctype.h>
1.168 stevesk 71: #include <errno.h>
1.151 stevesk 72: #include <paths.h>
1.153 stevesk 73: #include <signal.h>
1.174 stevesk 74: #include <stdio.h>
1.173 stevesk 75: #include <stdlib.h>
1.170 stevesk 76: #include <string.h>
1.328 deraadt 77: #include <stdarg.h>
1.150 stevesk 78: #include <termios.h>
1.175 deraadt 79: #include <pwd.h>
1.169 stevesk 80: #include <unistd.h>
1.266 deraadt 81: #include <limits.h>
1.1 deraadt 82:
1.175 deraadt 83: #include "xmalloc.h"
1.45 markus 84: #include "ssh.h"
85: #include "ssh2.h"
1.1 deraadt 86: #include "packet.h"
1.315 markus 87: #include "sshbuf.h"
1.15 markus 88: #include "compat.h"
1.74 markus 89: #include "channels.h"
1.15 markus 90: #include "dispatch.h"
1.317 markus 91: #include "sshkey.h"
1.175 deraadt 92: #include "cipher.h"
1.54 markus 93: #include "kex.h"
1.275 markus 94: #include "myproposal.h"
1.45 markus 95: #include "log.h"
1.261 millert 96: #include "misc.h"
1.45 markus 97: #include "readconf.h"
98: #include "clientloop.h"
1.147 djm 99: #include "sshconnect.h"
1.40 markus 100: #include "authfd.h"
1.45 markus 101: #include "atomicio.h"
1.118 deraadt 102: #include "sshpty.h"
1.123 djm 103: #include "match.h"
104: #include "msg.h"
1.262 djm 105: #include "ssherr.h"
1.267 djm 106: #include "hostfile.h"
1.319 djm 107:
1.39 markus 108: /* import options */
109: extern Options options;
110:
1.1 deraadt 111: /* Flag indicating that stdin should be redirected from /dev/null. */
112: extern int stdin_null_flag;
113:
1.116 dtucker 114: /* Flag indicating that no shell has been requested */
115: extern int no_shell_flag;
116:
1.286 djm 117: /* Flag indicating that ssh should daemonise after authentication is complete */
118: extern int fork_after_authentication_flag;
119:
1.123 djm 120: /* Control socket */
1.217 djm 121: extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */
1.123 djm 122:
1.13 markus 123: /*
124: * Name of the host we are connecting to. This is the name given on the
1.324 jmc 125: * command line, or the Hostname specified for the user-supplied name in a
1.13 markus 126: * configuration file.
127: */
1.1 deraadt 128: extern char *host;
129:
1.13 markus 130: /*
1.330 djm 131: * If this field is not NULL, the ForwardAgent socket is this path and different
132: * instead of SSH_AUTH_SOCK.
133: */
134: extern char *forward_agent_sock_path;
135:
136: /*
1.13 markus 137: * Flag to indicate that we have received a window change signal which has
138: * not yet been processed. This will cause a message indicating the new
139: * window size to be sent to the server a little later. This is volatile
140: * because this is updated in a signal handler.
141: */
1.88 markus 142: static volatile sig_atomic_t received_window_change_signal = 0;
143: static volatile sig_atomic_t received_signal = 0;
1.1 deraadt 144:
1.145 djm 145: /* Flag indicating whether the user's terminal is in non-blocking mode. */
1.1 deraadt 146: static int in_non_blocking_mode = 0;
147:
1.222 djm 148: /* Time when backgrounded control master using ControlPersist should exit */
149: static time_t control_persist_exit_time = 0;
150:
1.1 deraadt 151: /* Common data for the client loop code. */
1.217 djm 152: volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */
1.11 markus 153: static int last_was_cr; /* Last character was a newline. */
1.197 djm 154: static int exit_status; /* Used to store the command exit status. */
1.315 markus 155: static struct sshbuf *stderr_buffer; /* Used for final exit message. */
1.11 markus 156: static int connection_in; /* Connection to server (input). */
157: static int connection_out; /* Connection to server (output). */
1.56 markus 158: static int need_rekeying; /* Set to non-zero if rekeying is requested. */
1.221 djm 159: static int session_closed; /* In SSH2: login session closed. */
1.274 djm 160: static u_int x11_refuse_time; /* If >0, refuse x11 opens after this time. */
1.1 deraadt 161:
1.321 djm 162: static void client_init_dispatch(struct ssh *ssh);
1.16 markus 163: int session_ident = -1;
164:
1.195 djm 165: /* Track escape per proto2 channel */
166: struct escape_filter_ctx {
167: int escape_pending;
168: int escape_char;
169: };
170:
171: /* Context for channel confirmation replies */
1.190 djm 172: struct channel_reply_ctx {
173: const char *request_type;
1.234 djm 174: int id;
175: enum confirm_action action;
1.190 djm 176: };
177:
1.196 djm 178: /* Global request success/failure callbacks */
1.303 djm 179: /* XXX move to struct ssh? */
1.196 djm 180: struct global_confirm {
181: TAILQ_ENTRY(global_confirm) entry;
182: global_confirm_cb *cb;
183: void *ctx;
184: int ref_count;
185: };
186: TAILQ_HEAD(global_confirms, global_confirm);
187: static struct global_confirms global_confirms =
188: TAILQ_HEAD_INITIALIZER(global_confirms);
189:
1.315 markus 190: void ssh_process_session2_setup(int, int, int, struct sshbuf *);
1.123 djm 191:
1.1 deraadt 192: /* Restores stdin to blocking mode. */
193:
1.77 itojun 194: static void
1.49 itojun 195: leave_non_blocking(void)
1.1 deraadt 196: {
1.11 markus 197: if (in_non_blocking_mode) {
1.125 djm 198: unset_nonblock(fileno(stdin));
1.11 markus 199: in_non_blocking_mode = 0;
200: }
1.1 deraadt 201: }
202:
1.13 markus 203: /*
204: * Signal handler for the window change signal (SIGWINCH). This just sets a
205: * flag indicating that the window has changed.
206: */
1.157 deraadt 207: /*ARGSUSED */
1.77 itojun 208: static void
1.11 markus 209: window_change_handler(int sig)
1.1 deraadt 210: {
1.11 markus 211: received_window_change_signal = 1;
1.1 deraadt 212: }
213:
1.13 markus 214: /*
215: * Signal handler for signals that cause the program to terminate. These
216: * signals must be trapped to restore terminal modes.
217: */
1.157 deraadt 218: /*ARGSUSED */
1.77 itojun 219: static void
1.11 markus 220: signal_handler(int sig)
1.1 deraadt 221: {
1.75 markus 222: received_signal = sig;
223: quit_pending = 1;
1.1 deraadt 224: }
225:
1.13 markus 226: /*
1.222 djm 227: * Sets control_persist_exit_time to the absolute time when the
228: * backgrounded control master should exit due to expiry of the
229: * ControlPersist timeout. Sets it to 0 if we are not a backgrounded
230: * control master process, or if there is no ControlPersist timeout.
231: */
232: static void
1.303 djm 233: set_control_persist_exit_time(struct ssh *ssh)
1.222 djm 234: {
235: if (muxserver_sock == -1 || !options.control_persist
1.232 djm 236: || options.control_persist_timeout == 0) {
1.222 djm 237: /* not using a ControlPersist timeout */
238: control_persist_exit_time = 0;
1.303 djm 239: } else if (channel_still_open(ssh)) {
1.222 djm 240: /* some client connections are still open */
241: if (control_persist_exit_time > 0)
242: debug2("%s: cancel scheduled exit", __func__);
243: control_persist_exit_time = 0;
244: } else if (control_persist_exit_time <= 0) {
245: /* a client connection has recently closed */
1.251 dtucker 246: control_persist_exit_time = monotime() +
1.222 djm 247: (time_t)options.control_persist_timeout;
248: debug2("%s: schedule exit in %d seconds", __func__,
249: options.control_persist_timeout);
250: }
251: /* else we are already counting down to the timeout */
252: }
253:
1.238 dtucker 254: #define SSH_X11_VALID_DISPLAY_CHARS ":/.-_"
255: static int
256: client_x11_display_valid(const char *display)
257: {
258: size_t i, dlen;
259:
1.279 djm 260: if (display == NULL)
261: return 0;
262:
1.238 dtucker 263: dlen = strlen(display);
264: for (i = 0; i < dlen; i++) {
1.256 deraadt 265: if (!isalnum((u_char)display[i]) &&
1.238 dtucker 266: strchr(SSH_X11_VALID_DISPLAY_CHARS, display[i]) == NULL) {
267: debug("Invalid character '%c' in DISPLAY", display[i]);
268: return 0;
269: }
270: }
271: return 1;
272: }
273:
1.274 djm 274: #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
275: #define X11_TIMEOUT_SLACK 60
1.279 djm 276: int
1.303 djm 277: client_x11_get_proto(struct ssh *ssh, const char *display,
278: const char *xauth_path, u_int trusted, u_int timeout,
279: char **_proto, char **_data)
1.138 djm 280: {
1.318 djm 281: char *cmd, line[512], xdisplay[512];
1.279 djm 282: char xauthfile[PATH_MAX], xauthdir[PATH_MAX];
1.138 djm 283: static char proto[512], data[512];
284: FILE *f;
1.288 tedu 285: int got_data = 0, generated = 0, do_unlink = 0, r;
1.138 djm 286: struct stat st;
1.274 djm 287: u_int now, x11_timeout_real;
1.138 djm 288:
289: *_proto = proto;
290: *_data = data;
1.279 djm 291: proto[0] = data[0] = xauthfile[0] = xauthdir[0] = '\0';
1.138 djm 292:
1.279 djm 293: if (!client_x11_display_valid(display)) {
1.283 millert 294: if (display != NULL)
295: logit("DISPLAY \"%s\" invalid; disabling X11 forwarding",
296: display);
1.279 djm 297: return -1;
298: }
299: if (xauth_path != NULL && stat(xauth_path, &st) == -1) {
1.138 djm 300: debug("No xauth program.");
1.279 djm 301: xauth_path = NULL;
302: }
303:
304: if (xauth_path != NULL) {
1.138 djm 305: /*
306: * Handle FamilyLocal case where $DISPLAY does
307: * not match an authorization entry. For this we
308: * just try "xauth list unix:displaynum.screennum".
309: * XXX: "localhost" match to determine FamilyLocal
310: * is not perfect.
311: */
312: if (strncmp(display, "localhost:", 10) == 0) {
1.279 djm 313: if ((r = snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
314: display + 10)) < 0 ||
315: (size_t)r >= sizeof(xdisplay)) {
316: error("%s: display name too long", __func__);
317: return -1;
318: }
1.138 djm 319: display = xdisplay;
320: }
321: if (trusted == 0) {
1.274 djm 322: /*
1.279 djm 323: * Generate an untrusted X11 auth cookie.
324: *
1.274 djm 325: * The authentication cookie should briefly outlive
326: * ssh's willingness to forward X11 connections to
327: * avoid nasty fail-open behaviour in the X server.
328: */
1.279 djm 329: mktemp_proto(xauthdir, sizeof(xauthdir));
330: if (mkdtemp(xauthdir) == NULL) {
331: error("%s: mkdtemp: %s",
332: __func__, strerror(errno));
333: return -1;
334: }
335: do_unlink = 1;
336: if ((r = snprintf(xauthfile, sizeof(xauthfile),
337: "%s/xauthfile", xauthdir)) < 0 ||
338: (size_t)r >= sizeof(xauthfile)) {
339: error("%s: xauthfile path too long", __func__);
340: rmdir(xauthdir);
341: return -1;
342: }
343:
1.318 djm 344: if (timeout == 0) {
345: /* auth doesn't time out */
346: xasprintf(&cmd, "%s -f %s generate %s %s "
347: "untrusted 2>%s",
348: xauth_path, xauthfile, display,
349: SSH_X11_PROTO, _PATH_DEVNULL);
350: } else {
351: /* Add some slack to requested expiry */
352: if (timeout < UINT_MAX - X11_TIMEOUT_SLACK)
353: x11_timeout_real = timeout +
354: X11_TIMEOUT_SLACK;
355: else {
356: /* Don't overflow on long timeouts */
357: x11_timeout_real = UINT_MAX;
358: }
359: xasprintf(&cmd, "%s -f %s generate %s %s "
360: "untrusted timeout %u 2>%s",
361: xauth_path, xauthfile, display,
362: SSH_X11_PROTO, x11_timeout_real,
363: _PATH_DEVNULL);
364: }
1.322 djm 365: debug2("%s: xauth command: %s", __func__, cmd);
1.318 djm 366:
367: if (timeout != 0 && x11_refuse_time == 0) {
1.279 djm 368: now = monotime() + 1;
369: if (UINT_MAX - timeout < now)
370: x11_refuse_time = UINT_MAX;
371: else
372: x11_refuse_time = now + timeout;
1.303 djm 373: channel_set_x11_refuse_time(ssh,
374: x11_refuse_time);
1.138 djm 375: }
1.279 djm 376: if (system(cmd) == 0)
377: generated = 1;
1.318 djm 378: free(cmd);
1.138 djm 379: }
1.181 markus 380:
381: /*
382: * When in untrusted mode, we read the cookie only if it was
383: * successfully generated as an untrusted one in the step
384: * above.
385: */
386: if (trusted || generated) {
1.318 djm 387: xasprintf(&cmd,
1.181 markus 388: "%s %s%s list %s 2>" _PATH_DEVNULL,
389: xauth_path,
390: generated ? "-f " : "" ,
391: generated ? xauthfile : "",
392: display);
393: debug2("x11_get_proto: %s", cmd);
394: f = popen(cmd, "r");
395: if (f && fgets(line, sizeof(line), f) &&
396: sscanf(line, "%*s %511s %511s", proto, data) == 2)
397: got_data = 1;
398: if (f)
399: pclose(f);
1.318 djm 400: free(cmd);
1.279 djm 401: }
1.138 djm 402: }
403:
404: if (do_unlink) {
405: unlink(xauthfile);
406: rmdir(xauthdir);
407: }
408:
1.279 djm 409: /* Don't fall back to fake X11 data for untrusted forwarding */
410: if (!trusted && !got_data) {
411: error("Warning: untrusted X11 forwarding setup failed: "
412: "xauth key data not generated");
413: return -1;
414: }
415:
1.138 djm 416: /*
417: * If we didn't get authentication data, just make up some
418: * data. The forwarding code will check the validity of the
419: * response anyway, and substitute this data. The X11
420: * server, however, will ignore this fake data and use
421: * whatever authentication mechanisms it was using otherwise
422: * for the local connection.
423: */
424: if (!got_data) {
1.288 tedu 425: u_int8_t rnd[16];
426: u_int i;
1.138 djm 427:
428: logit("Warning: No xauth data; "
429: "using fake authentication data for X11 forwarding.");
430: strlcpy(proto, SSH_X11_PROTO, sizeof proto);
1.288 tedu 431: arc4random_buf(rnd, sizeof(rnd));
432: for (i = 0; i < sizeof(rnd); i++) {
1.138 djm 433: snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
1.288 tedu 434: rnd[i]);
1.138 djm 435: }
436: }
1.279 djm 437:
438: return 0;
1.1 deraadt 439: }
440:
1.13 markus 441: /*
442: * Checks if the client window has changed, and sends a packet about it to
443: * the server if so. The actual change is detected elsewhere (by a software
444: * interrupt on Unix); this just checks the flag and sends a message if
445: * appropriate.
446: */
1.1 deraadt 447:
1.77 itojun 448: static void
1.303 djm 449: client_check_window_change(struct ssh *ssh)
1.1 deraadt 450: {
1.292 djm 451: if (!received_window_change_signal)
1.16 markus 452: return;
453: received_window_change_signal = 0;
1.292 djm 454: debug2("%s: changed", __func__);
1.303 djm 455: channel_send_window_changes(ssh);
1.1 deraadt 456: }
457:
1.264 markus 458: static int
1.297 markus 459: client_global_request_reply(int type, u_int32_t seq, struct ssh *ssh)
1.117 markus 460: {
1.196 djm 461: struct global_confirm *gc;
462:
463: if ((gc = TAILQ_FIRST(&global_confirms)) == NULL)
1.264 markus 464: return 0;
1.196 djm 465: if (gc->cb != NULL)
1.303 djm 466: gc->cb(ssh, type, seq, gc->ctx);
1.196 djm 467: if (--gc->ref_count <= 0) {
468: TAILQ_REMOVE(&global_confirms, gc, entry);
1.342 jsg 469: freezero(gc, sizeof(*gc));
1.196 djm 470: }
471:
1.320 djm 472: ssh_packet_set_alive_timeouts(ssh, 0);
1.264 markus 473: return 0;
1.117 markus 474: }
475:
476: static void
1.320 djm 477: server_alive_check(struct ssh *ssh)
1.117 markus 478: {
1.320 djm 479: int r;
480:
481: if (ssh_packet_inc_alive_timeouts(ssh) > options.server_alive_count_max) {
1.228 djm 482: logit("Timeout, server %s not responding.", host);
1.176 markus 483: cleanup_exit(255);
484: }
1.320 djm 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)
1.322 djm 489: fatal("%s: send packet: %s", __func__, ssh_err(r));
1.196 djm 490: /* Insert an empty placeholder to maintain ordering */
491: client_register_global_confirm(NULL, NULL);
1.117 markus 492: }
493:
1.13 markus 494: /*
495: * Waits until the client can do something (some data becomes available on
496: * one of the file descriptors).
497: */
1.77 itojun 498: static void
1.303 djm 499: client_wait_until_can_do_something(struct ssh *ssh,
500: fd_set **readsetp, fd_set **writesetp,
1.130 avsm 501: int *maxfdp, u_int *nallocp, int rekeying)
1.11 markus 502: {
1.117 markus 503: struct timeval tv, *tvp;
1.222 djm 504: int timeout_secs;
1.251 dtucker 505: time_t minwait_secs = 0, server_alive_time = 0, now = monotime();
1.315 markus 506: int r, ret;
1.117 markus 507:
1.46 markus 508: /* Add any selections by the channel mechanism. */
1.321 djm 509: channel_prepare_select(ssh, readsetp, writesetp, maxfdp,
1.302 djm 510: nallocp, &minwait_secs);
1.11 markus 511:
1.292 djm 512: /* channel_prepare_select could have closed the last channel */
1.303 djm 513: if (session_closed && !channel_still_open(ssh) &&
1.320 djm 514: !ssh_packet_have_data_to_write(ssh)) {
1.292 djm 515: /* clear mask since we did not call select() */
516: memset(*readsetp, 0, *nallocp);
517: memset(*writesetp, 0, *nallocp);
518: return;
1.16 markus 519: }
1.11 markus 520:
1.294 djm 521: FD_SET(connection_in, *readsetp);
522:
1.11 markus 523: /* Select server connection if have data to write to the server. */
1.320 djm 524: if (ssh_packet_have_data_to_write(ssh))
1.46 markus 525: FD_SET(connection_out, *writesetp);
1.11 markus 526:
1.13 markus 527: /*
528: * Wait for something to happen. This will suspend the process until
529: * some selected descriptor can be read, written, or has some other
1.222 djm 530: * event pending, or a timeout expires.
1.13 markus 531: */
1.11 markus 532:
1.222 djm 533: timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */
1.292 djm 534: if (options.server_alive_interval > 0) {
1.222 djm 535: timeout_secs = options.server_alive_interval;
1.249 dtucker 536: server_alive_time = now + options.server_alive_interval;
537: }
1.292 djm 538: if (options.rekey_interval > 0 && !rekeying)
1.320 djm 539: timeout_secs = MINIMUM(timeout_secs,
540: ssh_packet_get_rekey_timeout(ssh));
1.303 djm 541: set_control_persist_exit_time(ssh);
1.222 djm 542: if (control_persist_exit_time > 0) {
1.287 deraadt 543: timeout_secs = MINIMUM(timeout_secs,
1.249 dtucker 544: control_persist_exit_time - now);
1.222 djm 545: if (timeout_secs < 0)
546: timeout_secs = 0;
547: }
1.239 djm 548: if (minwait_secs != 0)
1.287 deraadt 549: timeout_secs = MINIMUM(timeout_secs, (int)minwait_secs);
1.222 djm 550: if (timeout_secs == INT_MAX)
1.117 markus 551: tvp = NULL;
1.129 deraadt 552: else {
1.222 djm 553: tv.tv_sec = timeout_secs;
1.117 markus 554: tv.tv_usec = 0;
555: tvp = &tv;
556: }
1.222 djm 557:
1.117 markus 558: ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
1.326 deraadt 559: if (ret == -1) {
1.51 markus 560: /*
561: * We have to clear the select masks, because we return.
562: * We have to return, because the mainloop checks for the flags
563: * set by the signal handlers.
564: */
1.87 markus 565: memset(*readsetp, 0, *nallocp);
566: memset(*writesetp, 0, *nallocp);
1.50 deraadt 567:
1.11 markus 568: if (errno == EINTR)
569: return;
570: /* Note: we might still have data in the buffers. */
1.315 markus 571: if ((r = sshbuf_putf(stderr_buffer,
572: "select: %s\r\n", strerror(errno))) != 0)
573: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.11 markus 574: quit_pending = 1;
1.249 dtucker 575: } else if (ret == 0) {
576: /*
577: * Timeout. Could have been either keepalive or rekeying.
578: * Keepalive we check here, rekeying is checked in clientloop.
579: */
1.251 dtucker 580: if (server_alive_time != 0 && server_alive_time <= monotime())
1.320 djm 581: server_alive_check(ssh);
1.249 dtucker 582: }
583:
1.11 markus 584: }
585:
1.77 itojun 586: static void
1.315 markus 587: client_suspend_self(struct sshbuf *bin, struct sshbuf *bout, struct sshbuf *berr)
1.1 deraadt 588: {
1.11 markus 589: /* Flush stdout and stderr buffers. */
1.315 markus 590: if (sshbuf_len(bout) > 0)
591: atomicio(vwrite, fileno(stdout), sshbuf_mutable_ptr(bout),
592: sshbuf_len(bout));
593: if (sshbuf_len(berr) > 0)
594: atomicio(vwrite, fileno(stderr), sshbuf_mutable_ptr(berr),
595: sshbuf_len(berr));
1.11 markus 596:
1.233 djm 597: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.11 markus 598:
1.305 djm 599: sshbuf_reset(bin);
600: sshbuf_reset(bout);
601: sshbuf_reset(berr);
1.11 markus 602:
603: /* Send the suspend signal to the program itself. */
604: kill(getpid(), SIGTSTP);
605:
1.132 djm 606: /* Reset window sizes in case they have changed */
607: received_window_change_signal = 1;
1.11 markus 608:
1.233 djm 609: enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.11 markus 610: }
611:
1.77 itojun 612: static void
1.320 djm 613: client_process_net_input(struct ssh *ssh, fd_set *readset)
1.11 markus 614: {
1.17 markus 615: char buf[8192];
1.315 markus 616: int r, len;
1.11 markus 617:
1.13 markus 618: /*
619: * Read input from the server, and add any such data to the buffer of
620: * the packet subsystem.
621: */
1.11 markus 622: if (FD_ISSET(connection_in, readset)) {
623: /* Read as much as possible. */
1.280 markus 624: len = read(connection_in, buf, sizeof(buf));
625: if (len == 0) {
1.197 djm 626: /*
627: * Received EOF. The remote host has closed the
628: * connection.
629: */
1.315 markus 630: if ((r = sshbuf_putf(stderr_buffer,
1.197 djm 631: "Connection to %.300s closed by remote host.\r\n",
1.315 markus 632: host)) != 0)
633: fatal("%s: buffer error: %s",
634: __func__, ssh_err(r));
1.1 deraadt 635: quit_pending = 1;
636: return;
1.11 markus 637: }
1.13 markus 638: /*
639: * There is a kernel bug on Solaris that causes select to
640: * sometimes wake up even though there is no data available.
641: */
1.326 deraadt 642: if (len == -1 && (errno == EAGAIN || errno == EINTR))
1.11 markus 643: len = 0;
644:
1.326 deraadt 645: if (len == -1) {
1.197 djm 646: /*
647: * An error has encountered. Perhaps there is a
648: * network problem.
649: */
1.315 markus 650: if ((r = sshbuf_putf(stderr_buffer,
1.197 djm 651: "Read from remote host %.300s: %.100s\r\n",
1.315 markus 652: host, strerror(errno))) != 0)
653: fatal("%s: buffer error: %s",
654: __func__, ssh_err(r));
1.11 markus 655: quit_pending = 1;
656: return;
657: }
1.320 djm 658: ssh_packet_process_incoming(ssh, buf, len);
1.11 markus 659: }
1.17 markus 660: }
1.16 markus 661:
1.97 jakob 662: static void
1.303 djm 663: client_status_confirm(struct ssh *ssh, int type, Channel *c, void *ctx)
1.123 djm 664: {
1.190 djm 665: struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx;
666: char errmsg[256];
1.315 markus 667: int r, tochan;
1.190 djm 668:
1.234 djm 669: /*
670: * If a TTY was explicitly requested, then a failure to allocate
671: * one is fatal.
672: */
673: if (cr->action == CONFIRM_TTY &&
674: (options.request_tty == REQUEST_TTY_FORCE ||
675: options.request_tty == REQUEST_TTY_YES))
676: cr->action = CONFIRM_CLOSE;
677:
1.312 djm 678: /* XXX suppress on mux _client_ quietmode */
1.190 djm 679: tochan = options.log_level >= SYSLOG_LEVEL_ERROR &&
1.217 djm 680: c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE;
1.190 djm 681:
682: if (type == SSH2_MSG_CHANNEL_SUCCESS) {
683: debug2("%s request accepted on channel %d",
684: cr->request_type, c->self);
685: } else if (type == SSH2_MSG_CHANNEL_FAILURE) {
686: if (tochan) {
687: snprintf(errmsg, sizeof(errmsg),
688: "%s request failed\r\n", cr->request_type);
689: } else {
690: snprintf(errmsg, sizeof(errmsg),
691: "%s request failed on channel %d",
692: cr->request_type, c->self);
693: }
694: /* If error occurred on primary session channel, then exit */
1.234 djm 695: if (cr->action == CONFIRM_CLOSE && c->self == session_ident)
1.190 djm 696: fatal("%s", errmsg);
1.234 djm 697: /*
698: * If error occurred on mux client, append to
699: * their stderr.
700: */
701: if (tochan) {
1.315 markus 702: if ((r = sshbuf_put(c->extended, errmsg,
703: strlen(errmsg))) != 0)
704: fatal("%s: buffer error %s", __func__,
705: ssh_err(r));
1.234 djm 706: } else
1.190 djm 707: error("%s", errmsg);
1.234 djm 708: if (cr->action == CONFIRM_TTY) {
709: /*
710: * If a TTY allocation error occurred, then arrange
711: * for the correct TTY to leave raw mode.
712: */
713: if (c->self == session_ident)
714: leave_raw_mode(0);
715: else
1.303 djm 716: mux_tty_alloc_failed(ssh, c);
1.234 djm 717: } else if (cr->action == CONFIRM_CLOSE) {
1.303 djm 718: chan_read_failed(ssh, c);
719: chan_write_failed(ssh, c);
1.190 djm 720: }
721: }
1.250 djm 722: free(cr);
1.190 djm 723: }
724:
725: static void
1.303 djm 726: client_abandon_status_confirm(struct ssh *ssh, Channel *c, void *ctx)
1.190 djm 727: {
1.250 djm 728: free(ctx);
1.190 djm 729: }
1.129 deraadt 730:
1.236 djm 731: void
1.303 djm 732: client_expect_confirm(struct ssh *ssh, int id, const char *request,
1.234 djm 733: enum confirm_action action)
1.190 djm 734: {
1.255 djm 735: struct channel_reply_ctx *cr = xcalloc(1, sizeof(*cr));
1.123 djm 736:
1.190 djm 737: cr->request_type = request;
1.234 djm 738: cr->action = action;
1.123 djm 739:
1.303 djm 740: channel_register_status_confirm(ssh, id, client_status_confirm,
1.190 djm 741: client_abandon_status_confirm, cr);
1.196 djm 742: }
743:
744: void
745: client_register_global_confirm(global_confirm_cb *cb, void *ctx)
746: {
1.201 djm 747: struct global_confirm *gc, *last_gc;
1.196 djm 748:
749: /* Coalesce identical callbacks */
1.201 djm 750: last_gc = TAILQ_LAST(&global_confirms, global_confirms);
751: if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) {
752: if (++last_gc->ref_count >= INT_MAX)
753: fatal("%s: last_gc->ref_count = %d",
754: __func__, last_gc->ref_count);
1.196 djm 755: return;
756: }
757:
1.255 djm 758: gc = xcalloc(1, sizeof(*gc));
1.196 djm 759: gc->cb = cb;
760: gc->ctx = ctx;
761: gc->ref_count = 1;
762: TAILQ_INSERT_TAIL(&global_confirms, gc, entry);
1.123 djm 763: }
764:
765: static void
1.303 djm 766: process_cmdline(struct ssh *ssh)
1.97 jakob 767: {
768: void (*handler)(int);
1.261 millert 769: char *s, *cmd;
770: int ok, delete = 0, local = 0, remote = 0, dynamic = 0;
771: struct Forward fwd;
1.97 jakob 772:
1.257 tedu 773: memset(&fwd, 0, sizeof(fwd));
1.183 djm 774:
1.233 djm 775: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.332 dtucker 776: handler = ssh_signal(SIGINT, SIG_IGN);
1.99 markus 777: cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
1.97 jakob 778: if (s == NULL)
779: goto out;
1.256 deraadt 780: while (isspace((u_char)*s))
1.97 jakob 781: s++;
1.121 djm 782: if (*s == '-')
783: s++; /* Skip cmdline '-', if any */
1.120 dtucker 784: if (*s == '\0')
1.97 jakob 785: goto out;
1.121 djm 786:
1.122 djm 787: if (*s == 'h' || *s == 'H' || *s == '?') {
1.121 djm 788: logit("Commands:");
1.164 djm 789: logit(" -L[bind_address:]port:host:hostport "
790: "Request local forward");
791: logit(" -R[bind_address:]port:host:hostport "
792: "Request remote forward");
1.204 stevesk 793: logit(" -D[bind_address:]port "
794: "Request dynamic forward");
1.237 markus 795: logit(" -KL[bind_address:]port "
796: "Cancel local forward");
1.165 stevesk 797: logit(" -KR[bind_address:]port "
1.164 djm 798: "Cancel remote forward");
1.237 markus 799: logit(" -KD[bind_address:]port "
800: "Cancel dynamic forward");
1.146 reyk 801: if (!options.permit_local_command)
802: goto out;
1.164 djm 803: logit(" !args "
804: "Execute local command");
1.146 reyk 805: goto out;
806: }
807:
808: if (*s == '!' && options.permit_local_command) {
809: s++;
810: ssh_local_cmd(s);
1.121 djm 811: goto out;
812: }
813:
814: if (*s == 'K') {
815: delete = 1;
816: s++;
817: }
1.204 stevesk 818: if (*s == 'L')
819: local = 1;
820: else if (*s == 'R')
821: remote = 1;
822: else if (*s == 'D')
823: dynamic = 1;
824: else {
1.109 itojun 825: logit("Invalid command.");
1.97 jakob 826: goto out;
827: }
1.204 stevesk 828:
1.256 deraadt 829: while (isspace((u_char)*++s))
1.179 tedu 830: ;
1.97 jakob 831:
1.217 djm 832: /* XXX update list of forwards in options */
1.121 djm 833: if (delete) {
1.261 millert 834: /* We pass 1 for dynamicfwd to restrict to 1 or 2 fields. */
835: if (!parse_forward(&fwd, s, 1, 0)) {
836: logit("Bad forwarding close specification.");
1.121 djm 837: goto out;
838: }
1.237 markus 839: if (remote)
1.303 djm 840: ok = channel_request_rforward_cancel(ssh, &fwd) == 0;
1.237 markus 841: else if (dynamic)
1.303 djm 842: ok = channel_cancel_lport_listener(ssh, &fwd,
1.261 millert 843: 0, &options.fwd_opts) > 0;
1.237 markus 844: else
1.303 djm 845: ok = channel_cancel_lport_listener(ssh, &fwd,
1.261 millert 846: CHANNEL_CANCEL_PORT_STATIC,
847: &options.fwd_opts) > 0;
1.237 markus 848: if (!ok) {
1.290 dtucker 849: logit("Unknown port forwarding.");
1.237 markus 850: goto out;
851: }
852: logit("Canceled forwarding.");
1.121 djm 853: } else {
1.209 djm 854: if (!parse_forward(&fwd, s, dynamic, remote)) {
1.121 djm 855: logit("Bad forwarding specification.");
856: goto out;
857: }
1.204 stevesk 858: if (local || dynamic) {
1.303 djm 859: if (!channel_setup_local_fwd_listener(ssh, &fwd,
1.261 millert 860: &options.fwd_opts)) {
1.121 djm 861: logit("Port forwarding failed.");
862: goto out;
863: }
1.135 djm 864: } else {
1.303 djm 865: if (channel_request_remote_forwarding(ssh, &fwd) < 0) {
1.167 markus 866: logit("Port forwarding failed.");
867: goto out;
868: }
1.135 djm 869: }
1.121 djm 870: logit("Forwarding port.");
871: }
872:
1.97 jakob 873: out:
1.332 dtucker 874: ssh_signal(SIGINT, handler);
1.233 djm 875: enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.250 djm 876: free(cmd);
877: free(fwd.listen_host);
1.261 millert 878: free(fwd.listen_path);
1.250 djm 879: free(fwd.connect_host);
1.261 millert 880: free(fwd.connect_path);
1.97 jakob 881: }
882:
1.244 dtucker 883: /* reasons to suppress output of an escape command in help output */
884: #define SUPPRESS_NEVER 0 /* never suppress, always show */
1.292 djm 885: #define SUPPRESS_MUXCLIENT 1 /* don't show in mux client sessions */
886: #define SUPPRESS_MUXMASTER 2 /* don't show in mux master sessions */
887: #define SUPPRESS_SYSLOG 4 /* don't show when logging to syslog */
1.244 dtucker 888: struct escape_help_text {
889: const char *cmd;
890: const char *text;
891: unsigned int flags;
892: };
893: static struct escape_help_text esc_txt[] = {
894: {".", "terminate session", SUPPRESS_MUXMASTER},
895: {".", "terminate connection (and any multiplexed sessions)",
896: SUPPRESS_MUXCLIENT},
1.292 djm 897: {"B", "send a BREAK to the remote system", SUPPRESS_NEVER},
1.244 dtucker 898: {"C", "open a command line", SUPPRESS_MUXCLIENT},
1.292 djm 899: {"R", "request rekey", SUPPRESS_NEVER},
1.246 dtucker 900: {"V/v", "decrease/increase verbosity (LogLevel)", SUPPRESS_MUXCLIENT},
1.244 dtucker 901: {"^Z", "suspend ssh", SUPPRESS_MUXCLIENT},
902: {"#", "list forwarded connections", SUPPRESS_NEVER},
903: {"&", "background ssh (when waiting for connections to terminate)",
904: SUPPRESS_MUXCLIENT},
905: {"?", "this message", SUPPRESS_NEVER},
906: };
907:
908: static void
1.315 markus 909: print_escape_help(struct sshbuf *b, int escape_char, int mux_client,
910: int using_stderr)
1.244 dtucker 911: {
912: unsigned int i, suppress_flags;
1.315 markus 913: int r;
1.244 dtucker 914:
1.315 markus 915: if ((r = sshbuf_putf(b,
916: "%c?\r\nSupported escape sequences:\r\n", escape_char)) != 0)
917: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.244 dtucker 918:
1.292 djm 919: suppress_flags =
1.244 dtucker 920: (mux_client ? SUPPRESS_MUXCLIENT : 0) |
921: (mux_client ? 0 : SUPPRESS_MUXMASTER) |
922: (using_stderr ? 0 : SUPPRESS_SYSLOG);
923:
924: for (i = 0; i < sizeof(esc_txt)/sizeof(esc_txt[0]); i++) {
925: if (esc_txt[i].flags & suppress_flags)
926: continue;
1.315 markus 927: if ((r = sshbuf_putf(b, " %c%-3s - %s\r\n",
928: escape_char, esc_txt[i].cmd, esc_txt[i].text)) != 0)
929: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.244 dtucker 930: }
931:
1.315 markus 932: if ((r = sshbuf_putf(b,
1.246 dtucker 933: " %c%c - send the escape character by typing it twice\r\n"
1.244 dtucker 934: "(Note that escapes are only recognized immediately after "
1.315 markus 935: "newline.)\r\n", escape_char, escape_char)) != 0)
936: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.244 dtucker 937: }
938:
1.314 djm 939: /*
1.296 naddy 940: * Process the characters one by one.
1.195 djm 941: */
1.77 itojun 942: static int
1.303 djm 943: process_escapes(struct ssh *ssh, Channel *c,
1.315 markus 944: struct sshbuf *bin, struct sshbuf *bout, struct sshbuf *berr,
1.195 djm 945: char *buf, int len)
1.31 markus 946: {
947: pid_t pid;
1.315 markus 948: int r, bytes = 0;
1.42 markus 949: u_int i;
950: u_char ch;
1.31 markus 951: char *s;
1.294 djm 952: struct escape_filter_ctx *efc = c->filter_ctx == NULL ?
953: NULL : (struct escape_filter_ctx *)c->filter_ctx;
1.31 markus 954:
1.294 djm 955: if (c->filter_ctx == NULL)
956: return 0;
1.314 djm 957:
1.139 djm 958: if (len <= 0)
959: return (0);
960:
961: for (i = 0; i < (u_int)len; i++) {
1.31 markus 962: /* Get one character at a time. */
963: ch = buf[i];
964:
1.294 djm 965: if (efc->escape_pending) {
1.31 markus 966: /* We have previously seen an escape character. */
967: /* Clear the flag now. */
1.294 djm 968: efc->escape_pending = 0;
1.31 markus 969:
970: /* Process the escaped character. */
971: switch (ch) {
972: case '.':
973: /* Terminate the connection. */
1.315 markus 974: if ((r = sshbuf_putf(berr, "%c.\r\n",
975: efc->escape_char)) != 0)
976: fatal("%s: buffer error: %s",
977: __func__, ssh_err(r));
1.217 djm 978: if (c && c->ctl_chan != -1) {
1.303 djm 979: chan_read_failed(ssh, c);
980: chan_write_failed(ssh, c);
981: if (c->detach_user) {
982: c->detach_user(ssh,
983: c->self, NULL);
984: }
1.253 dtucker 985: c->type = SSH_CHANNEL_ABANDONED;
1.315 markus 986: sshbuf_reset(c->input);
1.303 djm 987: chan_ibuf_empty(ssh, c);
1.195 djm 988: return 0;
989: } else
990: quit_pending = 1;
1.31 markus 991: return -1;
992:
993: case 'Z' - 64:
1.195 djm 994: /* XXX support this for mux clients */
1.217 djm 995: if (c && c->ctl_chan != -1) {
1.245 dtucker 996: char b[16];
1.195 djm 997: noescape:
1.245 dtucker 998: if (ch == 'Z' - 64)
999: snprintf(b, sizeof b, "^Z");
1000: else
1001: snprintf(b, sizeof b, "%c", ch);
1.315 markus 1002: if ((r = sshbuf_putf(berr,
1.245 dtucker 1003: "%c%s escape not available to "
1.195 djm 1004: "multiplexed sessions\r\n",
1.315 markus 1005: efc->escape_char, b)) != 0)
1006: fatal("%s: buffer error: %s",
1007: __func__, ssh_err(r));
1.195 djm 1008: continue;
1009: }
1.197 djm 1010: /* Suspend the program. Inform the user */
1.315 markus 1011: if ((r = sshbuf_putf(berr,
1012: "%c^Z [suspend ssh]\r\n",
1013: efc->escape_char)) != 0)
1014: fatal("%s: buffer error: %s",
1015: __func__, ssh_err(r));
1.31 markus 1016:
1017: /* Restore terminal modes and suspend. */
1018: client_suspend_self(bin, bout, berr);
1019:
1020: /* We have been continued. */
1021: continue;
1022:
1.111 markus 1023: case 'B':
1.315 markus 1024: if ((r = sshbuf_putf(berr,
1025: "%cB\r\n", efc->escape_char)) != 0)
1026: fatal("%s: buffer error: %s",
1027: __func__, ssh_err(r));
1.303 djm 1028: channel_request_start(ssh, c->self, "break", 0);
1.315 markus 1029: if ((r = sshpkt_put_u32(ssh, 1000)) != 0 ||
1030: (r = sshpkt_send(ssh)) != 0)
1.322 djm 1031: fatal("%s: send packet: %s", __func__,
1.315 markus 1032: ssh_err(r));
1.111 markus 1033: continue;
1034:
1.54 markus 1035: case 'R':
1.292 djm 1036: if (datafellows & SSH_BUG_NOREKEY)
1037: logit("Server does not "
1038: "support re-keying");
1039: else
1040: need_rekeying = 1;
1.54 markus 1041: continue;
1042:
1.242 dtucker 1043: case 'V':
1044: /* FALLTHROUGH */
1045: case 'v':
1046: if (c && c->ctl_chan != -1)
1047: goto noescape;
1048: if (!log_is_on_stderr()) {
1.315 markus 1049: if ((r = sshbuf_putf(berr,
1.242 dtucker 1050: "%c%c [Logging to syslog]\r\n",
1.315 markus 1051: efc->escape_char, ch)) != 0)
1052: fatal("%s: buffer error: %s",
1053: __func__, ssh_err(r));
1.242 dtucker 1054: continue;
1055: }
1056: if (ch == 'V' && options.log_level >
1057: SYSLOG_LEVEL_QUIET)
1058: log_change_level(--options.log_level);
1059: if (ch == 'v' && options.log_level <
1060: SYSLOG_LEVEL_DEBUG3)
1061: log_change_level(++options.log_level);
1.315 markus 1062: if ((r = sshbuf_putf(berr,
1.294 djm 1063: "%c%c [LogLevel %s]\r\n",
1064: efc->escape_char, ch,
1.315 markus 1065: log_level_name(options.log_level))) != 0)
1066: fatal("%s: buffer error: %s",
1067: __func__, ssh_err(r));
1.242 dtucker 1068: continue;
1069:
1.31 markus 1070: case '&':
1.217 djm 1071: if (c && c->ctl_chan != -1)
1.195 djm 1072: goto noescape;
1.31 markus 1073: /*
1.197 djm 1074: * Detach the program (continue to serve
1075: * connections, but put in background and no
1076: * more new connections).
1.31 markus 1077: */
1078: /* Restore tty modes. */
1.233 djm 1079: leave_raw_mode(
1080: options.request_tty == REQUEST_TTY_FORCE);
1.31 markus 1081:
1082: /* Stop listening for new connections. */
1.303 djm 1083: channel_stop_listening(ssh);
1.31 markus 1084:
1.315 markus 1085: if ((r = sshbuf_putf(berr,
1086: "%c& [backgrounded]\n", efc->escape_char))
1087: != 0)
1088: fatal("%s: buffer error: %s",
1089: __func__, ssh_err(r));
1.31 markus 1090:
1091: /* Fork into background. */
1092: pid = fork();
1.326 deraadt 1093: if (pid == -1) {
1.31 markus 1094: error("fork: %.100s", strerror(errno));
1095: continue;
1096: }
1097: if (pid != 0) { /* This is the parent. */
1098: /* The parent just exits. */
1099: exit(0);
1100: }
1101: /* The child continues serving connections. */
1.292 djm 1102: /* fake EOF on stdin */
1.315 markus 1103: if ((r = sshbuf_put_u8(bin, 4)) != 0)
1104: fatal("%s: buffer error: %s",
1105: __func__, ssh_err(r));
1.292 djm 1106: return -1;
1.31 markus 1107: case '?':
1.294 djm 1108: print_escape_help(berr, efc->escape_char,
1.244 dtucker 1109: (c && c->ctl_chan != -1),
1110: log_is_on_stderr());
1.31 markus 1111: continue;
1112:
1113: case '#':
1.315 markus 1114: if ((r = sshbuf_putf(berr, "%c#\r\n",
1115: efc->escape_char)) != 0)
1116: fatal("%s: buffer error: %s",
1117: __func__, ssh_err(r));
1.303 djm 1118: s = channel_open_message(ssh);
1.315 markus 1119: if ((r = sshbuf_put(berr, s, strlen(s))) != 0)
1120: fatal("%s: buffer error: %s",
1121: __func__, ssh_err(r));
1.250 djm 1122: free(s);
1.97 jakob 1123: continue;
1124:
1125: case 'C':
1.217 djm 1126: if (c && c->ctl_chan != -1)
1.206 djm 1127: goto noescape;
1.303 djm 1128: process_cmdline(ssh);
1.31 markus 1129: continue;
1130:
1131: default:
1.294 djm 1132: if (ch != efc->escape_char) {
1.315 markus 1133: if ((r = sshbuf_put_u8(bin,
1134: efc->escape_char)) != 0)
1135: fatal("%s: buffer error: %s",
1136: __func__, ssh_err(r));
1.31 markus 1137: bytes++;
1138: }
1139: /* Escaped characters fall through here */
1140: break;
1141: }
1142: } else {
1143: /*
1.197 djm 1144: * The previous character was not an escape char.
1145: * Check if this is an escape.
1.31 markus 1146: */
1.294 djm 1147: if (last_was_cr && ch == efc->escape_char) {
1.197 djm 1148: /*
1149: * It is. Set the flag and continue to
1150: * next character.
1151: */
1.294 djm 1152: efc->escape_pending = 1;
1.31 markus 1153: continue;
1154: }
1155: }
1156:
1157: /*
1158: * Normal character. Record whether it was a newline,
1159: * and append it to the buffer.
1160: */
1161: last_was_cr = (ch == '\r' || ch == '\n');
1.315 markus 1162: if ((r = sshbuf_put_u8(bin, ch)) != 0)
1163: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.31 markus 1164: bytes++;
1165: }
1166: return bytes;
1167: }
1168:
1.13 markus 1169: /*
1.15 markus 1170: * Get packets from the connection input buffer, and process them as long as
1171: * there are packets available.
1172: *
1173: * Any unknown packets received during the actual
1174: * session cause the session to terminate. This is
1175: * intended to make debugging easier since no
1176: * confirmations are sent. Any compatible protocol
1177: * extensions must be negotiated during the
1178: * preparatory phase.
1179: */
1180:
1.77 itojun 1181: static void
1.321 djm 1182: client_process_buffered_input_packets(struct ssh *ssh)
1.15 markus 1183: {
1.321 djm 1184: ssh_dispatch_run_fatal(ssh, DISPATCH_NONBLOCK, &quit_pending);
1.15 markus 1185: }
1186:
1.31 markus 1187: /* scan buf[] for '~' before sending data to the peer */
1.30 markus 1188:
1.195 djm 1189: /* Helper: allocate a new escape_filter_ctx and fill in its escape char */
1190: void *
1191: client_new_escape_filter_ctx(int escape_char)
1192: {
1193: struct escape_filter_ctx *ret;
1194:
1.255 djm 1195: ret = xcalloc(1, sizeof(*ret));
1.195 djm 1196: ret->escape_pending = 0;
1197: ret->escape_char = escape_char;
1198: return (void *)ret;
1199: }
1200:
1.198 djm 1201: /* Free the escape filter context on channel free */
1202: void
1.303 djm 1203: client_filter_cleanup(struct ssh *ssh, int cid, void *ctx)
1.198 djm 1204: {
1.250 djm 1205: free(ctx);
1.198 djm 1206: }
1207:
1.195 djm 1208: int
1.303 djm 1209: client_simple_escape_filter(struct ssh *ssh, Channel *c, char *buf, int len)
1.30 markus 1210: {
1.190 djm 1211: if (c->extended_usage != CHAN_EXTENDED_WRITE)
1212: return 0;
1213:
1.303 djm 1214: return process_escapes(ssh, c, c->input, c->output, c->extended,
1.195 djm 1215: buf, len);
1.30 markus 1216: }
1217:
1.77 itojun 1218: static void
1.303 djm 1219: client_channel_closed(struct ssh *ssh, int id, void *arg)
1.60 markus 1220: {
1.303 djm 1221: channel_cancel_cleanup(ssh, id);
1.60 markus 1222: session_closed = 1;
1.233 djm 1223: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.60 markus 1224: }
1225:
1.15 markus 1226: /*
1.13 markus 1227: * Implements the interactive session with the server. This is called after
1228: * the user has been authenticated, and a command has been started on the
1.72 stevesk 1229: * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1230: * used as an escape character for terminating or suspending the session.
1.13 markus 1231: */
1.20 markus 1232: int
1.303 djm 1233: client_loop(struct ssh *ssh, int have_pty, int escape_char_arg,
1234: int ssh2_chan_id)
1.1 deraadt 1235: {
1.46 markus 1236: fd_set *readset = NULL, *writeset = NULL;
1.11 markus 1237: double start_time, total_time;
1.284 djm 1238: int r, max_fd = 0, max_fd2 = 0, len;
1.200 markus 1239: u_int64_t ibytes, obytes;
1.130 avsm 1240: u_int nalloc = 0;
1.11 markus 1241: char buf[100];
1242:
1243: debug("Entering interactive session.");
1.277 semarie 1244:
1.278 semarie 1245: if (options.control_master &&
1.286 djm 1246: !option_clear_or_none(options.control_path)) {
1.278 semarie 1247: debug("pledge: id");
1.327 mestre 1248: if (pledge("stdio rpath wpath cpath unix inet dns recvfd sendfd proc exec id tty",
1.278 semarie 1249: NULL) == -1)
1250: fatal("%s pledge(): %s", __func__, strerror(errno));
1251:
1252: } else if (options.forward_x11 || options.permit_local_command) {
1.277 semarie 1253: debug("pledge: exec");
1254: if (pledge("stdio rpath wpath cpath unix inet dns proc exec tty",
1255: NULL) == -1)
1256: fatal("%s pledge(): %s", __func__, strerror(errno));
1257:
1258: } else if (options.update_hostkeys) {
1259: debug("pledge: filesystem full");
1260: if (pledge("stdio rpath wpath cpath unix inet dns proc tty",
1261: NULL) == -1)
1262: fatal("%s pledge(): %s", __func__, strerror(errno));
1263:
1.286 djm 1264: } else if (!option_clear_or_none(options.proxy_command) ||
1265: fork_after_authentication_flag) {
1.277 semarie 1266: debug("pledge: proc");
1267: if (pledge("stdio cpath unix inet dns proc tty", NULL) == -1)
1268: fatal("%s pledge(): %s", __func__, strerror(errno));
1269:
1270: } else {
1271: debug("pledge: network");
1.300 mestre 1272: if (pledge("stdio unix inet dns proc tty", NULL) == -1)
1.277 semarie 1273: fatal("%s pledge(): %s", __func__, strerror(errno));
1274: }
1.11 markus 1275:
1.307 dtucker 1276: start_time = monotime_double();
1.11 markus 1277:
1278: /* Initialize variables. */
1279: last_was_cr = 1;
1280: exit_status = -1;
1.320 djm 1281: connection_in = ssh_packet_get_connection_in(ssh);
1282: connection_out = ssh_packet_get_connection_out(ssh);
1.287 deraadt 1283: max_fd = MAXIMUM(connection_in, connection_out);
1.46 markus 1284:
1.11 markus 1285: quit_pending = 0;
1286:
1.315 markus 1287: /* Initialize buffer. */
1288: if ((stderr_buffer = sshbuf_new()) == NULL)
1289: fatal("%s: sshbuf_new failed", __func__);
1.11 markus 1290:
1.321 djm 1291: client_init_dispatch(ssh);
1.15 markus 1292:
1.105 markus 1293: /*
1294: * Set signal handlers, (e.g. to restore non-blocking mode)
1295: * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1296: */
1.332 dtucker 1297: if (ssh_signal(SIGHUP, SIG_IGN) != SIG_IGN)
1298: ssh_signal(SIGHUP, signal_handler);
1299: if (ssh_signal(SIGINT, SIG_IGN) != SIG_IGN)
1300: ssh_signal(SIGINT, signal_handler);
1301: if (ssh_signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1302: ssh_signal(SIGQUIT, signal_handler);
1303: if (ssh_signal(SIGTERM, SIG_IGN) != SIG_IGN)
1304: ssh_signal(SIGTERM, signal_handler);
1305: ssh_signal(SIGWINCH, window_change_handler);
1.11 markus 1306:
1307: if (have_pty)
1.233 djm 1308: enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.11 markus 1309:
1.292 djm 1310: session_ident = ssh2_chan_id;
1311: if (session_ident != -1) {
1312: if (escape_char_arg != SSH_ESCAPECHAR_NONE) {
1.303 djm 1313: channel_register_filter(ssh, session_ident,
1.292 djm 1314: client_simple_escape_filter, NULL,
1315: client_filter_cleanup,
1316: client_new_escape_filter_ctx(
1317: escape_char_arg));
1.232 djm 1318: }
1.303 djm 1319: channel_register_cleanup(ssh, session_ident,
1.292 djm 1320: client_channel_closed, 0);
1.48 markus 1321: }
1.30 markus 1322:
1.11 markus 1323: /* Main loop of the client for the interactive session mode. */
1324: while (!quit_pending) {
1325:
1.13 markus 1326: /* Process buffered packets sent by the server. */
1.321 djm 1327: client_process_buffered_input_packets(ssh);
1.11 markus 1328:
1.303 djm 1329: if (session_closed && !channel_still_open(ssh))
1.60 markus 1330: break;
1331:
1.303 djm 1332: if (ssh_packet_is_rekeying(ssh)) {
1.56 markus 1333: debug("rekeying in progress");
1.284 djm 1334: } else if (need_rekeying) {
1335: /* manual rekey request */
1336: debug("need rekeying");
1.303 djm 1337: if ((r = kex_start_rekex(ssh)) != 0)
1.284 djm 1338: fatal("%s: kex_start_rekex: %s", __func__,
1339: ssh_err(r));
1340: need_rekeying = 0;
1.56 markus 1341: } else {
1342: /*
1343: * Make packets from buffered channel data, and
1344: * enqueue them for sending to the server.
1345: */
1.320 djm 1346: if (ssh_packet_not_very_much_data_to_write(ssh))
1.303 djm 1347: channel_output_poll(ssh);
1.11 markus 1348:
1.56 markus 1349: /*
1350: * Check if the window size has changed, and buffer a
1351: * message about it to the server if so.
1352: */
1.303 djm 1353: client_check_window_change(ssh);
1.11 markus 1354:
1.56 markus 1355: if (quit_pending)
1356: break;
1357: }
1.13 markus 1358: /*
1359: * Wait until we have something to do (something becomes
1360: * available on one of the descriptors).
1361: */
1.81 markus 1362: max_fd2 = max_fd;
1.303 djm 1363: client_wait_until_can_do_something(ssh, &readset, &writeset,
1364: &max_fd2, &nalloc, ssh_packet_is_rekeying(ssh));
1.11 markus 1365:
1366: if (quit_pending)
1367: break;
1368:
1.56 markus 1369: /* Do channel operations unless rekeying in progress. */
1.303 djm 1370: if (!ssh_packet_is_rekeying(ssh))
1371: channel_after_select(ssh, readset, writeset);
1.11 markus 1372:
1.17 markus 1373: /* Buffer input from the connection. */
1.320 djm 1374: client_process_net_input(ssh, readset);
1.17 markus 1375:
1376: if (quit_pending)
1377: break;
1.11 markus 1378:
1.197 djm 1379: /*
1380: * Send as much buffered packet data as possible to the
1381: * sender.
1382: */
1.338 djm 1383: if (FD_ISSET(connection_out, writeset)) {
1384: if ((r = ssh_packet_write_poll(ssh)) != 0) {
1385: sshpkt_fatal(ssh, r,
1386: "%s: ssh_packet_write_poll", __func__);
1387: }
1388: }
1.222 djm 1389:
1390: /*
1391: * If we are a backgrounded control master, and the
1392: * timeout has expired without any active client
1393: * connections, then quit.
1394: */
1395: if (control_persist_exit_time > 0) {
1.251 dtucker 1396: if (monotime() >= control_persist_exit_time) {
1.222 djm 1397: debug("ControlPersist timeout expired");
1398: break;
1399: }
1400: }
1.11 markus 1401: }
1.250 djm 1402: free(readset);
1403: free(writeset);
1.11 markus 1404:
1405: /* Terminate the session. */
1406:
1407: /* Stop watching for window change. */
1.332 dtucker 1408: ssh_signal(SIGWINCH, SIG_DFL);
1.211 andreas 1409:
1.320 djm 1410: if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
1411: (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_BY_APPLICATION)) != 0 ||
1412: (r = sshpkt_put_cstring(ssh, "disconnected by user")) != 0 ||
1413: (r = sshpkt_put_cstring(ssh, "")) != 0 || /* language tag */
1414: (r = sshpkt_send(ssh)) != 0 ||
1415: (r = ssh_packet_write_wait(ssh)) != 0)
1.322 djm 1416: fatal("%s: send disconnect: %s", __func__, ssh_err(r));
1.11 markus 1417:
1.303 djm 1418: channel_free_all(ssh);
1.11 markus 1419:
1.75 markus 1420: if (have_pty)
1.233 djm 1421: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.75 markus 1422:
1423: /* restore blocking io */
1424: if (!isatty(fileno(stdin)))
1425: unset_nonblock(fileno(stdin));
1426: if (!isatty(fileno(stdout)))
1427: unset_nonblock(fileno(stdout));
1428: if (!isatty(fileno(stderr)))
1429: unset_nonblock(fileno(stderr));
1.116 dtucker 1430:
1431: /*
1432: * If there was no shell or command requested, there will be no remote
1433: * exit status to be returned. In that case, clear error code if the
1434: * connection was deliberately terminated at this end.
1435: */
1436: if (no_shell_flag && received_signal == SIGTERM) {
1437: received_signal = 0;
1438: exit_status = 0;
1439: }
1.75 markus 1440:
1.301 dtucker 1441: if (received_signal) {
1442: verbose("Killed by signal %d.", (int) received_signal);
1443: cleanup_exit(0);
1444: }
1.75 markus 1445:
1.13 markus 1446: /*
1447: * In interactive mode (with pseudo tty) display a message indicating
1448: * that the connection has been closed.
1449: */
1.11 markus 1450: if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1.315 markus 1451: if ((r = sshbuf_putf(stderr_buffer,
1452: "Connection to %.64s closed.\r\n", host)) != 0)
1453: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.11 markus 1454: }
1.70 markus 1455:
1.11 markus 1456: /* Output any buffered data for stderr. */
1.315 markus 1457: if (sshbuf_len(stderr_buffer) > 0) {
1.230 djm 1458: len = atomicio(vwrite, fileno(stderr),
1.315 markus 1459: (u_char *)sshbuf_ptr(stderr_buffer),
1460: sshbuf_len(stderr_buffer));
1461: if (len < 0 || (u_int)len != sshbuf_len(stderr_buffer))
1.11 markus 1462: error("Write failed flushing stderr buffer.");
1.315 markus 1463: else if ((r = sshbuf_consume(stderr_buffer, len)) != 0)
1464: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1.11 markus 1465: }
1466:
1467: /* Clear and free any buffers. */
1.281 jsg 1468: explicit_bzero(buf, sizeof(buf));
1.315 markus 1469: sshbuf_free(stderr_buffer);
1.11 markus 1470:
1471: /* Report bytes transferred, and transfer rates. */
1.307 dtucker 1472: total_time = monotime_double() - start_time;
1.320 djm 1473: ssh_packet_get_bytes(ssh, &ibytes, &obytes);
1.200 markus 1474: verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds",
1.229 djm 1475: (unsigned long long)obytes, (unsigned long long)ibytes, total_time);
1.11 markus 1476: if (total_time > 0)
1.200 markus 1477: verbose("Bytes per second: sent %.1f, received %.1f",
1478: obytes / total_time, ibytes / total_time);
1.11 markus 1479: /* Return the exit status of the program. */
1480: debug("Exit status %d", exit_status);
1481: return exit_status;
1.15 markus 1482: }
1483:
1484: /*********/
1485:
1.77 itojun 1486: static Channel *
1.303 djm 1487: client_request_forwarded_tcpip(struct ssh *ssh, const char *request_type,
1488: int rchan, u_int rwindow, u_int rmaxpack)
1.40 markus 1489: {
1.103 deraadt 1490: Channel *c = NULL;
1.289 markus 1491: struct sshbuf *b = NULL;
1.40 markus 1492: char *listen_address, *originator_address;
1.320 djm 1493: u_int listen_port, originator_port;
1.289 markus 1494: int r;
1.40 markus 1495:
1496: /* Get rest of the packet */
1.320 djm 1497: if ((r = sshpkt_get_cstring(ssh, &listen_address, NULL)) != 0 ||
1498: (r = sshpkt_get_u32(ssh, &listen_port)) != 0 ||
1499: (r = sshpkt_get_cstring(ssh, &originator_address, NULL)) != 0 ||
1500: (r = sshpkt_get_u32(ssh, &originator_port)) != 0 ||
1501: (r = sshpkt_get_end(ssh)) != 0)
1.322 djm 1502: fatal("%s: parse packet: %s", __func__, ssh_err(r));
1.40 markus 1503:
1.261 millert 1504: debug("%s: listen %s port %d, originator %s port %d", __func__,
1505: listen_address, listen_port, originator_address, originator_port);
1.191 djm 1506:
1.320 djm 1507: if (listen_port > 0xffff)
1508: error("%s: invalid listen port", __func__);
1509: else if (originator_port > 0xffff)
1510: error("%s: invalid originator port", __func__);
1511: else {
1512: c = channel_connect_by_listen_address(ssh,
1513: listen_address, listen_port, "forwarded-tcpip",
1514: originator_address);
1515: }
1.40 markus 1516:
1.289 markus 1517: if (c != NULL && c->type == SSH_CHANNEL_MUX_CLIENT) {
1518: if ((b = sshbuf_new()) == NULL) {
1519: error("%s: alloc reply", __func__);
1520: goto out;
1521: }
1522: /* reconstruct and send to muxclient */
1523: if ((r = sshbuf_put_u8(b, 0)) != 0 || /* padlen */
1524: (r = sshbuf_put_u8(b, SSH2_MSG_CHANNEL_OPEN)) != 0 ||
1525: (r = sshbuf_put_cstring(b, request_type)) != 0 ||
1526: (r = sshbuf_put_u32(b, rchan)) != 0 ||
1527: (r = sshbuf_put_u32(b, rwindow)) != 0 ||
1528: (r = sshbuf_put_u32(b, rmaxpack)) != 0 ||
1529: (r = sshbuf_put_cstring(b, listen_address)) != 0 ||
1530: (r = sshbuf_put_u32(b, listen_port)) != 0 ||
1531: (r = sshbuf_put_cstring(b, originator_address)) != 0 ||
1532: (r = sshbuf_put_u32(b, originator_port)) != 0 ||
1.303 djm 1533: (r = sshbuf_put_stringb(c->output, b)) != 0) {
1.289 markus 1534: error("%s: compose for muxclient %s", __func__,
1535: ssh_err(r));
1536: goto out;
1537: }
1538: }
1539:
1540: out:
1541: sshbuf_free(b);
1.250 djm 1542: free(originator_address);
1543: free(listen_address);
1.40 markus 1544: return c;
1545: }
1546:
1.103 deraadt 1547: static Channel *
1.303 djm 1548: client_request_forwarded_streamlocal(struct ssh *ssh,
1549: const char *request_type, int rchan)
1.261 millert 1550: {
1551: Channel *c = NULL;
1552: char *listen_path;
1.320 djm 1553: int r;
1.261 millert 1554:
1555: /* Get the remote path. */
1.320 djm 1556: if ((r = sshpkt_get_cstring(ssh, &listen_path, NULL)) != 0 ||
1557: (r = sshpkt_get_string(ssh, NULL, NULL)) != 0 || /* reserved */
1558: (r = sshpkt_get_end(ssh)) != 0)
1.322 djm 1559: fatal("%s: parse packet: %s", __func__, ssh_err(r));
1.261 millert 1560:
1.322 djm 1561: debug("%s: request: %s", __func__, listen_path);
1.261 millert 1562:
1.303 djm 1563: c = channel_connect_by_listen_path(ssh, listen_path,
1.261 millert 1564: "forwarded-streamlocal@openssh.com", "forwarded-streamlocal");
1565: free(listen_path);
1566: return c;
1567: }
1568:
1569: static Channel *
1.303 djm 1570: client_request_x11(struct ssh *ssh, const char *request_type, int rchan)
1.40 markus 1571: {
1572: Channel *c = NULL;
1573: char *originator;
1.321 djm 1574: u_int originator_port;
1.320 djm 1575: int r, sock;
1.40 markus 1576:
1577: if (!options.forward_x11) {
1578: error("Warning: ssh server tried X11 forwarding.");
1.197 djm 1579: error("Warning: this is probably a break-in attempt by a "
1580: "malicious server.");
1.221 djm 1581: return NULL;
1582: }
1.274 djm 1583: if (x11_refuse_time != 0 && (u_int)monotime() >= x11_refuse_time) {
1.221 djm 1584: verbose("Rejected X11 connection after ForwardX11Timeout "
1585: "expired");
1.40 markus 1586: return NULL;
1587: }
1.320 djm 1588: if ((r = sshpkt_get_cstring(ssh, &originator, NULL)) != 0 ||
1.321 djm 1589: (r = sshpkt_get_u32(ssh, &originator_port)) != 0 ||
1.320 djm 1590: (r = sshpkt_get_end(ssh)) != 0)
1.322 djm 1591: fatal("%s: parse packet: %s", __func__, ssh_err(r));
1.40 markus 1592: /* XXX check permission */
1.321 djm 1593: /* XXX range check originator port? */
1594: debug("client_request_x11: request from %s %u", originator,
1.47 markus 1595: originator_port);
1.250 djm 1596: free(originator);
1.303 djm 1597: sock = x11_connect_display(ssh);
1.67 markus 1598: if (sock < 0)
1599: return NULL;
1.303 djm 1600: c = channel_new(ssh, "x11",
1.67 markus 1601: SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1.110 markus 1602: CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1.82 markus 1603: c->force_drain = 1;
1.40 markus 1604: return c;
1605: }
1606:
1.103 deraadt 1607: static Channel *
1.303 djm 1608: client_request_agent(struct ssh *ssh, const char *request_type, int rchan)
1.40 markus 1609: {
1610: Channel *c = NULL;
1.262 djm 1611: int r, sock;
1.40 markus 1612:
1613: if (!options.forward_agent) {
1614: error("Warning: ssh server tried agent forwarding.");
1.197 djm 1615: error("Warning: this is probably a break-in attempt by a "
1616: "malicious server.");
1.40 markus 1617: return NULL;
1618: }
1.330 djm 1619: if (forward_agent_sock_path == NULL) {
1620: r = ssh_get_authentication_socket(&sock);
1621: } else {
1622: r = ssh_get_authentication_socket_path(forward_agent_sock_path, &sock);
1623: }
1624: if (r != 0) {
1.262 djm 1625: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1626: debug("%s: ssh_get_authentication_socket: %s",
1627: __func__, ssh_err(r));
1.67 markus 1628: return NULL;
1.262 djm 1629: }
1.303 djm 1630: c = channel_new(ssh, "authentication agent connection",
1.67 markus 1631: SSH_CHANNEL_OPEN, sock, sock, -1,
1.185 dtucker 1632: CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0,
1.110 markus 1633: "authentication agent connection", 1);
1.82 markus 1634: c->force_drain = 1;
1.40 markus 1635: return c;
1.180 djm 1636: }
1637:
1.306 djm 1638: char *
1.303 djm 1639: client_request_tun_fwd(struct ssh *ssh, int tun_mode,
1.343 ! djm 1640: int local_tun, int remote_tun, channel_open_fn *cb, void *cbctx)
1.180 djm 1641: {
1642: Channel *c;
1.320 djm 1643: int r, fd;
1.306 djm 1644: char *ifname = NULL;
1.180 djm 1645:
1646: if (tun_mode == SSH_TUNMODE_NO)
1647: return 0;
1648:
1649: debug("Requesting tun unit %d in mode %d", local_tun, tun_mode);
1650:
1651: /* Open local tunnel device */
1.306 djm 1652: if ((fd = tun_open(local_tun, tun_mode, &ifname)) == -1) {
1.180 djm 1653: error("Tunnel device open failed.");
1.306 djm 1654: return NULL;
1.180 djm 1655: }
1.306 djm 1656: debug("Tunnel forwarding using interface %s", ifname);
1.180 djm 1657:
1.303 djm 1658: c = channel_new(ssh, "tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1.180 djm 1659: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
1660: c->datagram = 1;
1.343 ! djm 1661:
! 1662: if (cb != NULL)
! 1663: channel_register_open_confirm(ssh, c->self, cb, cbctx);
1.180 djm 1664:
1.320 djm 1665: if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN)) != 0 ||
1666: (r = sshpkt_put_cstring(ssh, "tun@openssh.com")) != 0 ||
1667: (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
1668: (r = sshpkt_put_u32(ssh, c->local_window_max)) != 0 ||
1669: (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 ||
1670: (r = sshpkt_put_u32(ssh, tun_mode)) != 0 ||
1671: (r = sshpkt_put_u32(ssh, remote_tun)) != 0 ||
1672: (r = sshpkt_send(ssh)) != 0)
1.321 djm 1673: sshpkt_fatal(ssh, r, "%s: send reply", __func__);
1.180 djm 1674:
1.306 djm 1675: return ifname;
1.40 markus 1676: }
1677:
1.22 markus 1678: /* XXXX move to generic input handler */
1.264 markus 1679: static int
1.297 markus 1680: client_input_channel_open(int type, u_int32_t seq, struct ssh *ssh)
1.22 markus 1681: {
1682: Channel *c = NULL;
1.320 djm 1683: char *ctype = NULL;
1684: int r;
1685: u_int rchan;
1686: size_t len;
1687: u_int rmaxpack, rwindow;
1688:
1689: if ((r = sshpkt_get_cstring(ssh, &ctype, &len)) != 0 ||
1690: (r = sshpkt_get_u32(ssh, &rchan)) != 0 ||
1691: (r = sshpkt_get_u32(ssh, &rwindow)) != 0 ||
1692: (r = sshpkt_get_u32(ssh, &rmaxpack)) != 0)
1693: goto out;
1.22 markus 1694:
1.24 markus 1695: debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1.22 markus 1696: ctype, rchan, rwindow, rmaxpack);
1697:
1.40 markus 1698: if (strcmp(ctype, "forwarded-tcpip") == 0) {
1.303 djm 1699: c = client_request_forwarded_tcpip(ssh, ctype, rchan, rwindow,
1.289 markus 1700: rmaxpack);
1.261 millert 1701: } else if (strcmp(ctype, "forwarded-streamlocal@openssh.com") == 0) {
1.303 djm 1702: c = client_request_forwarded_streamlocal(ssh, ctype, rchan);
1.40 markus 1703: } else if (strcmp(ctype, "x11") == 0) {
1.303 djm 1704: c = client_request_x11(ssh, ctype, rchan);
1.40 markus 1705: } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1.303 djm 1706: c = client_request_agent(ssh, ctype, rchan);
1.22 markus 1707: }
1.289 markus 1708: if (c != NULL && c->type == SSH_CHANNEL_MUX_CLIENT) {
1709: debug3("proxied to downstream: %s", ctype);
1710: } else if (c != NULL) {
1.22 markus 1711: debug("confirm %s", ctype);
1712: c->remote_id = rchan;
1.304 djm 1713: c->have_remote_id = 1;
1.22 markus 1714: c->remote_window = rwindow;
1715: c->remote_maxpacket = rmaxpack;
1.69 markus 1716: if (c->type != SSH_CHANNEL_CONNECTING) {
1.320 djm 1717: if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 ||
1718: (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
1719: (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
1720: (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
1721: (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 ||
1722: (r = sshpkt_send(ssh)) != 0)
1723: sshpkt_fatal(ssh, r, "%s: send reply", __func__);
1.69 markus 1724: }
1.22 markus 1725: } else {
1726: debug("failure %s", ctype);
1.320 djm 1727: if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE)) != 0 ||
1728: (r = sshpkt_put_u32(ssh, rchan)) != 0 ||
1729: (r = sshpkt_put_u32(ssh, SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED)) != 0 ||
1730: (r = sshpkt_put_cstring(ssh, "open failed")) != 0 ||
1731: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1732: (r = sshpkt_send(ssh)) != 0)
1733: sshpkt_fatal(ssh, r, "%s: send failure", __func__);
1.22 markus 1734: }
1.320 djm 1735: r = 0;
1736: out:
1.250 djm 1737: free(ctype);
1.320 djm 1738: return r;
1.22 markus 1739: }
1.267 djm 1740:
1.264 markus 1741: static int
1.297 markus 1742: client_input_channel_req(int type, u_int32_t seq, struct ssh *ssh)
1.48 markus 1743: {
1744: Channel *c = NULL;
1.320 djm 1745: char *rtype = NULL;
1746: u_char reply;
1747: u_int id, exitval;
1748: int r, success = 0;
1749:
1750: if ((r = sshpkt_get_u32(ssh, &id)) != 0)
1751: return r;
1752: if (id <= INT_MAX)
1753: c = channel_lookup(ssh, id);
1.297 markus 1754: if (channel_proxy_upstream(c, type, seq, ssh))
1.289 markus 1755: return 0;
1.320 djm 1756: if ((r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 ||
1757: (r = sshpkt_get_u8(ssh, &reply)) != 0)
1758: goto out;
1.48 markus 1759:
1.320 djm 1760: debug("client_input_channel_req: channel %u rtype %s reply %d",
1.48 markus 1761: id, rtype, reply);
1762:
1.320 djm 1763: if (c == NULL) {
1.197 djm 1764: error("client_input_channel_req: channel %d: "
1765: "unknown channel", id);
1.193 markus 1766: } else if (strcmp(rtype, "eow@openssh.com") == 0) {
1.320 djm 1767: if ((r = sshpkt_get_end(ssh)) != 0)
1768: goto out;
1.303 djm 1769: chan_rcvd_eow(ssh, c);
1.48 markus 1770: } else if (strcmp(rtype, "exit-status") == 0) {
1.320 djm 1771: if ((r = sshpkt_get_u32(ssh, &exitval)) != 0)
1772: goto out;
1.217 djm 1773: if (c->ctl_chan != -1) {
1.303 djm 1774: mux_exit_message(ssh, c, exitval);
1.215 djm 1775: success = 1;
1.320 djm 1776: } else if ((int)id == session_ident) {
1.215 djm 1777: /* Record exit value of local session */
1.123 djm 1778: success = 1;
1779: exit_status = exitval;
1.215 djm 1780: } else {
1.218 djm 1781: /* Probably for a mux channel that has already closed */
1782: debug("%s: no sink for exit-status on channel %d",
1783: __func__, id);
1.123 djm 1784: }
1.320 djm 1785: if ((r = sshpkt_get_end(ssh)) != 0)
1786: goto out;
1.48 markus 1787: }
1.259 djm 1788: if (reply && c != NULL && !(c->flags & CHAN_CLOSE_SENT)) {
1.304 djm 1789: if (!c->have_remote_id)
1790: fatal("%s: channel %d: no remote_id",
1791: __func__, c->self);
1.320 djm 1792: if ((r = sshpkt_start(ssh, success ?
1793: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE)) != 0 ||
1794: (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
1795: (r = sshpkt_send(ssh)) != 0)
1796: sshpkt_fatal(ssh, r, "%s: send failure", __func__);
1.48 markus 1797: }
1.320 djm 1798: r = 0;
1799: out:
1.250 djm 1800: free(rtype);
1.320 djm 1801: return r;
1.48 markus 1802: }
1.267 djm 1803:
1.269 djm 1804: struct hostkeys_update_ctx {
1805: /* The hostname and (optionally) IP address string for the server */
1806: char *host_str, *ip_str;
1807:
1808: /*
1809: * Keys received from the server and a flag for each indicating
1810: * whether they already exist in known_hosts.
1811: * keys_seen is filled in by hostkeys_find() and later (for new
1812: * keys) by client_global_hostkeys_private_confirm().
1813: */
1814: struct sshkey **keys;
1815: int *keys_seen;
1.314 djm 1816: size_t nkeys, nnew;
1.269 djm 1817:
1818: /*
1819: * Keys that are in known_hosts, but were not present in the update
1820: * from the server (i.e. scheduled to be deleted).
1821: * Filled in by hostkeys_find().
1822: */
1823: struct sshkey **old_keys;
1824: size_t nold;
1825: };
1826:
1827: static void
1828: hostkeys_update_ctx_free(struct hostkeys_update_ctx *ctx)
1829: {
1830: size_t i;
1831:
1832: if (ctx == NULL)
1833: return;
1834: for (i = 0; i < ctx->nkeys; i++)
1835: sshkey_free(ctx->keys[i]);
1836: free(ctx->keys);
1837: free(ctx->keys_seen);
1838: for (i = 0; i < ctx->nold; i++)
1839: sshkey_free(ctx->old_keys[i]);
1840: free(ctx->old_keys);
1841: free(ctx->host_str);
1842: free(ctx->ip_str);
1843: free(ctx);
1844: }
1845:
1846: static int
1847: hostkeys_find(struct hostkey_foreach_line *l, void *_ctx)
1848: {
1849: struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx;
1850: size_t i;
1851: struct sshkey **tmp;
1852:
1.293 djm 1853: if (l->status != HKF_STATUS_MATCHED || l->key == NULL)
1.269 djm 1854: return 0;
1855:
1856: /* Mark off keys we've already seen for this host */
1857: for (i = 0; i < ctx->nkeys; i++) {
1858: if (sshkey_equal(l->key, ctx->keys[i])) {
1859: debug3("%s: found %s key at %s:%ld", __func__,
1860: sshkey_ssh_name(ctx->keys[i]), l->path, l->linenum);
1861: ctx->keys_seen[i] = 1;
1862: return 0;
1863: }
1864: }
1865: /* This line contained a key that not offered by the server */
1866: debug3("%s: deprecated %s key at %s:%ld", __func__,
1867: sshkey_ssh_name(l->key), l->path, l->linenum);
1.299 deraadt 1868: if ((tmp = recallocarray(ctx->old_keys, ctx->nold, ctx->nold + 1,
1.269 djm 1869: sizeof(*ctx->old_keys))) == NULL)
1.299 deraadt 1870: fatal("%s: recallocarray failed nold = %zu",
1.269 djm 1871: __func__, ctx->nold);
1872: ctx->old_keys = tmp;
1873: ctx->old_keys[ctx->nold++] = l->key;
1874: l->key = NULL;
1875:
1876: return 0;
1877: }
1878:
1879: static void
1.337 djm 1880: hostkey_change_preamble(LogLevel loglevel)
1.269 djm 1881: {
1.336 djm 1882: do_log2(loglevel, "The server has updated its host keys.");
1883: do_log2(loglevel, "These changes were verified by the server's "
1884: "existing trusted key.");
1885: }
1886:
1887: static void
1888: update_known_hosts(struct hostkeys_update_ctx *ctx)
1889: {
1890: int r, was_raw = 0, first = 1;
1891: int asking = options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK;
1892: LogLevel loglevel = asking ? SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_VERBOSE;
1.269 djm 1893: char *fp, *response;
1894: size_t i;
1.333 djm 1895: struct stat sb;
1.269 djm 1896:
1897: for (i = 0; i < ctx->nkeys; i++) {
1898: if (ctx->keys_seen[i] != 2)
1899: continue;
1900: if ((fp = sshkey_fingerprint(ctx->keys[i],
1901: options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
1902: fatal("%s: sshkey_fingerprint failed", __func__);
1.336 djm 1903: if (first && asking)
1.337 djm 1904: hostkey_change_preamble(loglevel);
1.269 djm 1905: do_log2(loglevel, "Learned new hostkey: %s %s",
1906: sshkey_type(ctx->keys[i]), fp);
1.336 djm 1907: first = 0;
1.269 djm 1908: free(fp);
1909: }
1910: for (i = 0; i < ctx->nold; i++) {
1911: if ((fp = sshkey_fingerprint(ctx->old_keys[i],
1912: options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
1913: fatal("%s: sshkey_fingerprint failed", __func__);
1.336 djm 1914: if (first && asking)
1.337 djm 1915: hostkey_change_preamble(loglevel);
1.269 djm 1916: do_log2(loglevel, "Deprecating obsolete hostkey: %s %s",
1917: sshkey_type(ctx->old_keys[i]), fp);
1.336 djm 1918: first = 0;
1.269 djm 1919: free(fp);
1920: }
1921: if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) {
1.271 djm 1922: if (get_saved_tio() != NULL) {
1923: leave_raw_mode(1);
1924: was_raw = 1;
1925: }
1.269 djm 1926: response = NULL;
1927: for (i = 0; !quit_pending && i < 3; i++) {
1928: free(response);
1929: response = read_passphrase("Accept updated hostkeys? "
1930: "(yes/no): ", RP_ECHO);
1931: if (strcasecmp(response, "yes") == 0)
1932: break;
1933: else if (quit_pending || response == NULL ||
1934: strcasecmp(response, "no") == 0) {
1935: options.update_hostkeys = 0;
1936: break;
1937: } else {
1938: do_log2(loglevel, "Please enter "
1939: "\"yes\" or \"no\"");
1940: }
1941: }
1942: if (quit_pending || i >= 3 || response == NULL)
1943: options.update_hostkeys = 0;
1944: free(response);
1.271 djm 1945: if (was_raw)
1946: enter_raw_mode(1);
1.269 djm 1947: }
1.333 djm 1948: if (options.update_hostkeys == 0)
1949: return;
1.269 djm 1950: /*
1951: * Now that all the keys are verified, we can go ahead and replace
1952: * them in known_hosts (assuming SSH_UPDATE_HOSTKEYS_ASK didn't
1953: * cancel the operation).
1954: */
1.333 djm 1955: for (i = 0; i < options.num_user_hostfiles; i++) {
1956: /*
1957: * NB. keys are only added to hostfiles[0], for the rest we
1958: * just delete the hostname entries.
1959: */
1960: if (stat(options.user_hostfiles[i], &sb) != 0) {
1961: if (errno == ENOENT) {
1962: debug("%s: known hosts file %s does not exist",
1963: __func__, strerror(errno));
1964: } else {
1965: error("%s: known hosts file %s inaccessible",
1966: __func__, strerror(errno));
1967: }
1968: continue;
1969: }
1970: if ((r = hostfile_replace_entries(options.user_hostfiles[i],
1971: ctx->host_str, ctx->ip_str,
1972: i == 0 ? ctx->keys : NULL, i == 0 ? ctx->nkeys : 0,
1973: options.hash_known_hosts, 0,
1974: options.fingerprint_hash)) != 0) {
1975: error("%s: hostfile_replace_entries failed for %s: %s",
1976: __func__, options.user_hostfiles[i], ssh_err(r));
1977: }
1978: }
1.269 djm 1979: }
1980:
1981: static void
1.303 djm 1982: client_global_hostkeys_private_confirm(struct ssh *ssh, int type,
1983: u_int32_t seq, void *_ctx)
1.269 djm 1984: {
1985: struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx;
1986: size_t i, ndone;
1987: struct sshbuf *signdata;
1.309 djm 1988: int r, kexsigtype, use_kexsigtype;
1.269 djm 1989: const u_char *sig;
1990: size_t siglen;
1991:
1992: if (ctx->nnew == 0)
1993: fatal("%s: ctx->nnew == 0", __func__); /* sanity */
1994: if (type != SSH2_MSG_REQUEST_SUCCESS) {
1995: error("Server failed to confirm ownership of "
1996: "private host keys");
1997: hostkeys_update_ctx_free(ctx);
1998: return;
1999: }
1.309 djm 2000: kexsigtype = sshkey_type_plain(
2001: sshkey_type_from_name(ssh->kex->hostkey_alg));
2002:
1.269 djm 2003: if ((signdata = sshbuf_new()) == NULL)
2004: fatal("%s: sshbuf_new failed", __func__);
2005: /* Don't want to accidentally accept an unbound signature */
2006: if (ssh->kex->session_id_len == 0)
2007: fatal("%s: ssh->kex->session_id_len == 0", __func__);
2008: /*
2009: * Expect a signature for each of the ctx->nnew private keys we
2010: * haven't seen before. They will be in the same order as the
2011: * ctx->keys where the corresponding ctx->keys_seen[i] == 0.
2012: */
2013: for (ndone = i = 0; i < ctx->nkeys; i++) {
2014: if (ctx->keys_seen[i])
2015: continue;
2016: /* Prepare data to be signed: session ID, unique string, key */
2017: sshbuf_reset(signdata);
1.270 djm 2018: if ( (r = sshbuf_put_cstring(signdata,
2019: "hostkeys-prove-00@openssh.com")) != 0 ||
2020: (r = sshbuf_put_string(signdata, ssh->kex->session_id,
1.269 djm 2021: ssh->kex->session_id_len)) != 0 ||
2022: (r = sshkey_puts(ctx->keys[i], signdata)) != 0)
2023: fatal("%s: failed to prepare signature: %s",
2024: __func__, ssh_err(r));
2025: /* Extract and verify signature */
2026: if ((r = sshpkt_get_string_direct(ssh, &sig, &siglen)) != 0) {
2027: error("%s: couldn't parse message: %s",
2028: __func__, ssh_err(r));
2029: goto out;
2030: }
1.309 djm 2031: /*
2032: * For RSA keys, prefer to use the signature type negotiated
2033: * during KEX to the default (SHA1).
2034: */
2035: use_kexsigtype = kexsigtype == KEY_RSA &&
2036: sshkey_type_plain(ctx->keys[i]->type) == KEY_RSA;
1.269 djm 2037: if ((r = sshkey_verify(ctx->keys[i], sig, siglen,
1.308 djm 2038: sshbuf_ptr(signdata), sshbuf_len(signdata),
1.329 djm 2039: use_kexsigtype ? ssh->kex->hostkey_alg : NULL, 0,
2040: NULL)) != 0) {
1.269 djm 2041: error("%s: server gave bad signature for %s key %zu",
2042: __func__, sshkey_type(ctx->keys[i]), i);
2043: goto out;
2044: }
2045: /* Key is good. Mark it as 'seen' */
2046: ctx->keys_seen[i] = 2;
2047: ndone++;
2048: }
2049: if (ndone != ctx->nnew)
2050: fatal("%s: ndone != ctx->nnew (%zu / %zu)", __func__,
2051: ndone, ctx->nnew); /* Shouldn't happen */
1.320 djm 2052: if ((r = sshpkt_get_end(ssh)) != 0) {
2053: error("%s: protocol error", __func__);
2054: goto out;
2055: }
1.269 djm 2056:
2057: /* Make the edits to known_hosts */
2058: update_known_hosts(ctx);
2059: out:
2060: hostkeys_update_ctx_free(ctx);
2061: }
2062:
1.267 djm 2063: /*
1.291 djm 2064: * Returns non-zero if the key is accepted by HostkeyAlgorithms.
2065: * Made slightly less trivial by the multiple RSA signature algorithm names.
2066: */
2067: static int
2068: key_accepted_by_hostkeyalgs(const struct sshkey *key)
2069: {
2070: const char *ktype = sshkey_ssh_name(key);
1.331 dtucker 2071: const char *hostkeyalgs = options.hostkeyalgorithms;
1.291 djm 2072:
2073: if (key == NULL || key->type == KEY_UNSPEC)
2074: return 0;
2075: if (key->type == KEY_RSA &&
2076: (match_pattern_list("rsa-sha2-256", hostkeyalgs, 0) == 1 ||
2077: match_pattern_list("rsa-sha2-512", hostkeyalgs, 0) == 1))
2078: return 1;
2079: return match_pattern_list(ktype, hostkeyalgs, 0) == 1;
2080: }
2081:
2082: /*
1.270 djm 2083: * Handle hostkeys-00@openssh.com global request to inform the client of all
1.267 djm 2084: * the server's hostkeys. The keys are checked against the user's
2085: * HostkeyAlgorithms preference before they are accepted.
2086: */
2087: static int
1.321 djm 2088: client_input_hostkeys(struct ssh *ssh)
1.267 djm 2089: {
2090: const u_char *blob = NULL;
1.269 djm 2091: size_t i, len = 0;
1.267 djm 2092: struct sshbuf *buf = NULL;
1.269 djm 2093: struct sshkey *key = NULL, **tmp;
2094: int r;
2095: char *fp;
1.267 djm 2096: static int hostkeys_seen = 0; /* XXX use struct ssh */
1.268 djm 2097: extern struct sockaddr_storage hostaddr; /* XXX from ssh.c */
1.272 djm 2098: struct hostkeys_update_ctx *ctx = NULL;
1.267 djm 2099:
2100: if (hostkeys_seen)
2101: fatal("%s: server already sent hostkeys", __func__);
1.269 djm 2102: if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK &&
2103: options.batch_mode)
2104: return 1; /* won't ask in batchmode, so don't even try */
1.267 djm 2105: if (!options.update_hostkeys || options.num_user_hostfiles <= 0)
2106: return 1;
1.272 djm 2107:
2108: ctx = xcalloc(1, sizeof(*ctx));
1.269 djm 2109: while (ssh_packet_remaining(ssh) > 0) {
1.267 djm 2110: sshkey_free(key);
2111: key = NULL;
1.269 djm 2112: if ((r = sshpkt_get_string_direct(ssh, &blob, &len)) != 0) {
2113: error("%s: couldn't parse message: %s",
2114: __func__, ssh_err(r));
2115: goto out;
2116: }
1.270 djm 2117: if ((r = sshkey_from_blob(blob, len, &key)) != 0) {
1.335 djm 2118: do_log2(r == SSH_ERR_KEY_TYPE_UNKNOWN ?
2119: SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_ERROR,
2120: "%s: parse key: %s", __func__, ssh_err(r));
2121: continue;
1.270 djm 2122: }
1.267 djm 2123: fp = sshkey_fingerprint(key, options.fingerprint_hash,
2124: SSH_FP_DEFAULT);
2125: debug3("%s: received %s key %s", __func__,
2126: sshkey_type(key), fp);
2127: free(fp);
1.275 markus 2128:
1.291 djm 2129: if (!key_accepted_by_hostkeyalgs(key)) {
1.267 djm 2130: debug3("%s: %s key not permitted by HostkeyAlgorithms",
2131: __func__, sshkey_ssh_name(key));
2132: continue;
2133: }
1.269 djm 2134: /* Skip certs */
2135: if (sshkey_is_cert(key)) {
2136: debug3("%s: %s key is a certificate; skipping",
2137: __func__, sshkey_ssh_name(key));
2138: continue;
2139: }
2140: /* Ensure keys are unique */
2141: for (i = 0; i < ctx->nkeys; i++) {
2142: if (sshkey_equal(key, ctx->keys[i])) {
2143: error("%s: received duplicated %s host key",
2144: __func__, sshkey_ssh_name(key));
2145: goto out;
2146: }
2147: }
2148: /* Key is good, record it */
1.299 deraadt 2149: if ((tmp = recallocarray(ctx->keys, ctx->nkeys, ctx->nkeys + 1,
1.269 djm 2150: sizeof(*ctx->keys))) == NULL)
1.299 deraadt 2151: fatal("%s: recallocarray failed nkeys = %zu",
1.269 djm 2152: __func__, ctx->nkeys);
2153: ctx->keys = tmp;
2154: ctx->keys[ctx->nkeys++] = key;
1.267 djm 2155: key = NULL;
2156: }
2157:
1.269 djm 2158: if (ctx->nkeys == 0) {
1.270 djm 2159: debug("%s: server sent no hostkeys", __func__);
1.267 djm 2160: goto out;
2161: }
1.270 djm 2162:
1.269 djm 2163: if ((ctx->keys_seen = calloc(ctx->nkeys,
2164: sizeof(*ctx->keys_seen))) == NULL)
2165: fatal("%s: calloc failed", __func__);
1.267 djm 2166:
1.268 djm 2167: get_hostfile_hostname_ipaddr(host,
2168: options.check_host_ip ? (struct sockaddr *)&hostaddr : NULL,
1.269 djm 2169: options.port, &ctx->host_str,
2170: options.check_host_ip ? &ctx->ip_str : NULL);
1.268 djm 2171:
1.269 djm 2172: /* Find which keys we already know about. */
1.333 djm 2173: for (i = 0; i < options.num_user_hostfiles; i++) {
2174: debug("%s: searching %s for %s / %s", __func__,
1.339 dtucker 2175: options.user_hostfiles[i], ctx->host_str,
1.340 dtucker 2176: ctx->ip_str ? ctx->ip_str : "(none)");
1.333 djm 2177: if ((r = hostkeys_foreach(options.user_hostfiles[i],
2178: hostkeys_find, ctx, ctx->host_str, ctx->ip_str,
2179: HKF_WANT_PARSE_KEY|HKF_WANT_MATCH)) != 0) {
2180: if (r == SSH_ERR_SYSTEM_ERROR && errno == ENOENT) {
1.334 djm 2181: debug("%s: hostkeys file %s does not exist",
1.333 djm 2182: __func__, options.user_hostfiles[i]);
2183: continue;
2184: }
2185: error("%s: hostkeys_foreach failed for %s: %s",
2186: __func__, options.user_hostfiles[i], ssh_err(r));
2187: goto out;
2188: }
1.267 djm 2189: }
2190:
1.269 djm 2191: /* Figure out if we have any new keys to add */
2192: ctx->nnew = 0;
2193: for (i = 0; i < ctx->nkeys; i++) {
2194: if (!ctx->keys_seen[i])
2195: ctx->nnew++;
2196: }
2197:
2198: debug3("%s: %zu keys from server: %zu new, %zu retained. %zu to remove",
2199: __func__, ctx->nkeys, ctx->nnew, ctx->nkeys - ctx->nnew, ctx->nold);
2200:
2201: if (ctx->nnew == 0 && ctx->nold != 0) {
2202: /* We have some keys to remove. Just do it. */
2203: update_known_hosts(ctx);
2204: } else if (ctx->nnew != 0) {
2205: /*
2206: * We have received hitherto-unseen keys from the server.
2207: * Ask the server to confirm ownership of the private halves.
2208: */
2209: debug3("%s: asking server to prove ownership for %zu keys",
2210: __func__, ctx->nnew);
2211: if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
2212: (r = sshpkt_put_cstring(ssh,
1.270 djm 2213: "hostkeys-prove-00@openssh.com")) != 0 ||
1.269 djm 2214: (r = sshpkt_put_u8(ssh, 1)) != 0) /* bool: want reply */
2215: fatal("%s: cannot prepare packet: %s",
2216: __func__, ssh_err(r));
2217: if ((buf = sshbuf_new()) == NULL)
2218: fatal("%s: sshbuf_new", __func__);
2219: for (i = 0; i < ctx->nkeys; i++) {
2220: if (ctx->keys_seen[i])
2221: continue;
2222: sshbuf_reset(buf);
2223: if ((r = sshkey_putb(ctx->keys[i], buf)) != 0)
2224: fatal("%s: sshkey_putb: %s",
2225: __func__, ssh_err(r));
2226: if ((r = sshpkt_put_stringb(ssh, buf)) != 0)
2227: fatal("%s: sshpkt_put_string: %s",
2228: __func__, ssh_err(r));
2229: }
2230: if ((r = sshpkt_send(ssh)) != 0)
2231: fatal("%s: sshpkt_send: %s", __func__, ssh_err(r));
2232: client_register_global_confirm(
2233: client_global_hostkeys_private_confirm, ctx);
2234: ctx = NULL; /* will be freed in callback */
2235: }
2236:
1.267 djm 2237: /* Success */
2238: out:
1.269 djm 2239: hostkeys_update_ctx_free(ctx);
1.267 djm 2240: sshkey_free(key);
2241: sshbuf_free(buf);
1.269 djm 2242: /*
2243: * NB. Return success for all cases. The server doesn't need to know
2244: * what the client does with its hosts file.
2245: */
2246: return 1;
1.267 djm 2247: }
2248:
1.264 markus 2249: static int
1.297 markus 2250: client_input_global_request(int type, u_int32_t seq, struct ssh *ssh)
1.95 markus 2251: {
2252: char *rtype;
1.320 djm 2253: u_char want_reply;
2254: int r, success = 0;
1.95 markus 2255:
1.320 djm 2256: if ((r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 ||
2257: (r = sshpkt_get_u8(ssh, &want_reply)) != 0)
2258: goto out;
1.117 markus 2259: debug("client_input_global_request: rtype %s want_reply %d",
2260: rtype, want_reply);
1.270 djm 2261: if (strcmp(rtype, "hostkeys-00@openssh.com") == 0)
1.321 djm 2262: success = client_input_hostkeys(ssh);
1.95 markus 2263: if (want_reply) {
1.320 djm 2264: if ((r = sshpkt_start(ssh, success ? SSH2_MSG_REQUEST_SUCCESS :
2265: SSH2_MSG_REQUEST_FAILURE)) != 0 ||
2266: (r = sshpkt_send(ssh)) != 0 ||
2267: (r = ssh_packet_write_wait(ssh)) != 0)
2268: goto out;
1.95 markus 2269: }
1.320 djm 2270: r = 0;
2271: out:
1.250 djm 2272: free(rtype);
1.320 djm 2273: return r;
1.95 markus 2274: }
1.22 markus 2275:
1.123 djm 2276: void
1.303 djm 2277: client_session2_setup(struct ssh *ssh, int id, int want_tty, int want_subsystem,
1.315 markus 2278: const char *term, struct termios *tiop, int in_fd, struct sshbuf *cmd,
2279: char **env)
1.123 djm 2280: {
1.320 djm 2281: int i, j, matched, len, r;
1.313 djm 2282: char *name, *val;
1.132 djm 2283: Channel *c = NULL;
1.123 djm 2284:
2285: debug2("%s: id %d", __func__, id);
2286:
1.303 djm 2287: if ((c = channel_lookup(ssh, id)) == NULL)
2288: fatal("%s: channel %d: unknown channel", __func__, id);
1.224 djm 2289:
1.320 djm 2290: ssh_packet_set_interactive(ssh, want_tty,
1.224 djm 2291: options.ip_qos_interactive, options.ip_qos_bulk);
1.132 djm 2292:
1.123 djm 2293: if (want_tty) {
2294: struct winsize ws;
2295:
2296: /* Store window size in the packet. */
1.326 deraadt 2297: if (ioctl(in_fd, TIOCGWINSZ, &ws) == -1)
1.123 djm 2298: memset(&ws, 0, sizeof(ws));
2299:
1.303 djm 2300: channel_request_start(ssh, id, "pty-req", 1);
2301: client_expect_confirm(ssh, id, "PTY allocation", CONFIRM_TTY);
1.320 djm 2302: if ((r = sshpkt_put_cstring(ssh, term != NULL ? term : ""))
2303: != 0 ||
2304: (r = sshpkt_put_u32(ssh, (u_int)ws.ws_col)) != 0 ||
2305: (r = sshpkt_put_u32(ssh, (u_int)ws.ws_row)) != 0 ||
2306: (r = sshpkt_put_u32(ssh, (u_int)ws.ws_xpixel)) != 0 ||
2307: (r = sshpkt_put_u32(ssh, (u_int)ws.ws_ypixel)) != 0)
1.322 djm 2308: fatal("%s: build packet: %s", __func__, ssh_err(r));
1.194 djm 2309: if (tiop == NULL)
2310: tiop = get_saved_tio();
1.316 markus 2311: ssh_tty_make_modes(ssh, -1, tiop);
1.320 djm 2312: if ((r = sshpkt_send(ssh)) != 0)
1.322 djm 2313: fatal("%s: send packet: %s", __func__, ssh_err(r));
1.123 djm 2314: /* XXX wait for reply */
1.132 djm 2315: c->client_tty = 1;
1.123 djm 2316: }
2317:
2318: /* Transfer any environment variables from client to server */
1.126 djm 2319: if (options.num_send_env != 0 && env != NULL) {
1.123 djm 2320: debug("Sending environment.");
1.126 djm 2321: for (i = 0; env[i] != NULL; i++) {
1.123 djm 2322: /* Split */
1.126 djm 2323: name = xstrdup(env[i]);
1.123 djm 2324: if ((val = strchr(name, '=')) == NULL) {
1.250 djm 2325: free(name);
1.123 djm 2326: continue;
2327: }
2328: *val++ = '\0';
2329:
2330: matched = 0;
2331: for (j = 0; j < options.num_send_env; j++) {
2332: if (match_pattern(name, options.send_env[j])) {
2333: matched = 1;
2334: break;
2335: }
2336: }
2337: if (!matched) {
2338: debug3("Ignored env %s", name);
1.250 djm 2339: free(name);
1.123 djm 2340: continue;
2341: }
2342:
2343: debug("Sending env %s = %s", name, val);
1.303 djm 2344: channel_request_start(ssh, id, "env", 0);
1.320 djm 2345: if ((r = sshpkt_put_cstring(ssh, name)) != 0 ||
2346: (r = sshpkt_put_cstring(ssh, val)) != 0 ||
1.322 djm 2347: (r = sshpkt_send(ssh)) != 0) {
2348: fatal("%s: send packet: %s",
2349: __func__, ssh_err(r));
2350: }
1.250 djm 2351: free(name);
1.123 djm 2352: }
1.313 djm 2353: }
2354: for (i = 0; i < options.num_setenv; i++) {
2355: /* Split */
2356: name = xstrdup(options.setenv[i]);
2357: if ((val = strchr(name, '=')) == NULL) {
2358: free(name);
2359: continue;
2360: }
2361: *val++ = '\0';
2362:
2363: debug("Setting env %s = %s", name, val);
2364: channel_request_start(ssh, id, "env", 0);
1.320 djm 2365: if ((r = sshpkt_put_cstring(ssh, name)) != 0 ||
2366: (r = sshpkt_put_cstring(ssh, val)) != 0 ||
2367: (r = sshpkt_send(ssh)) != 0)
1.322 djm 2368: fatal("%s: send packet: %s", __func__, ssh_err(r));
1.313 djm 2369: free(name);
1.123 djm 2370: }
2371:
1.315 markus 2372: len = sshbuf_len(cmd);
1.123 djm 2373: if (len > 0) {
2374: if (len > 900)
2375: len = 900;
2376: if (want_subsystem) {
1.190 djm 2377: debug("Sending subsystem: %.*s",
1.315 markus 2378: len, (const u_char*)sshbuf_ptr(cmd));
1.303 djm 2379: channel_request_start(ssh, id, "subsystem", 1);
2380: client_expect_confirm(ssh, id, "subsystem",
2381: CONFIRM_CLOSE);
1.123 djm 2382: } else {
1.190 djm 2383: debug("Sending command: %.*s",
1.315 markus 2384: len, (const u_char*)sshbuf_ptr(cmd));
1.303 djm 2385: channel_request_start(ssh, id, "exec", 1);
2386: client_expect_confirm(ssh, id, "exec", CONFIRM_CLOSE);
1.123 djm 2387: }
1.320 djm 2388: if ((r = sshpkt_put_stringb(ssh, cmd)) != 0 ||
2389: (r = sshpkt_send(ssh)) != 0)
1.322 djm 2390: fatal("%s: send command: %s", __func__, ssh_err(r));
1.123 djm 2391: } else {
1.303 djm 2392: channel_request_start(ssh, id, "shell", 1);
2393: client_expect_confirm(ssh, id, "shell", CONFIRM_CLOSE);
1.322 djm 2394: if ((r = sshpkt_send(ssh)) != 0) {
2395: fatal("%s: send shell request: %s",
2396: __func__, ssh_err(r));
2397: }
1.123 djm 2398: }
2399: }
2400:
1.77 itojun 2401: static void
1.321 djm 2402: client_init_dispatch(struct ssh *ssh)
1.16 markus 2403: {
1.321 djm 2404: ssh_dispatch_init(ssh, &dispatch_protocol_error);
1.100 markus 2405:
1.321 djm 2406: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
2407: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_DATA, &channel_input_data);
2408: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
2409: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
2410: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
2411: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2412: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2413: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
2414: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
2415: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm);
2416: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm);
2417: ssh_dispatch_set(ssh, SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
1.55 markus 2418:
2419: /* rekeying */
1.321 djm 2420: ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, &kex_input_kexinit);
1.100 markus 2421:
2422: /* global request reply messages */
1.321 djm 2423: ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
2424: ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
1.232 djm 2425: }
2426:
2427: void
2428: client_stop_mux(void)
2429: {
2430: if (options.control_path != NULL && muxserver_sock != -1)
2431: unlink(options.control_path);
2432: /*
1.247 dtucker 2433: * If we are in persist mode, or don't have a shell, signal that we
2434: * should close when all active channels are closed.
1.232 djm 2435: */
1.247 dtucker 2436: if (options.control_persist || no_shell_flag) {
1.232 djm 2437: session_closed = 1;
1.235 djm 2438: setproctitle("[stopped mux]");
2439: }
1.113 markus 2440: }
2441:
2442: /* client specific fatal cleanup */
2443: void
1.114 markus 2444: cleanup_exit(int i)
1.113 markus 2445: {
1.233 djm 2446: leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1.113 markus 2447: leave_non_blocking();
1.192 djm 2448: if (options.control_path != NULL && muxserver_sock != -1)
1.123 djm 2449: unlink(options.control_path);
1.223 djm 2450: ssh_kill_proxy_command();
1.114 markus 2451: _exit(i);
1.1 deraadt 2452: }
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