1657 lines
46 KiB
C
1657 lines
46 KiB
C
/* $OpenBSD: ssh.c,v 1.364 2011/08/02 23:15:03 djm Exp $ */
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/* $FreeBSD$ */
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/*
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* Author: Tatu Ylonen <ylo@cs.hut.fi>
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* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
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* All rights reserved
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* Ssh client program. This program can be used to log into a remote machine.
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* The software supports strong authentication, encryption, and forwarding
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* of X11, TCP/IP, and authentication connections.
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*
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* As far as I am concerned, the code I have written for this software
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* can be used freely for any purpose. Any derived versions of this
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* software must be clearly marked as such, and if the derived work is
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* incompatible with the protocol description in the RFC file, it must be
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* called by a name other than "ssh" or "Secure Shell".
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*
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* Copyright (c) 1999 Niels Provos. All rights reserved.
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* Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved.
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*
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* Modified to work with SSL by Niels Provos <provos@citi.umich.edu>
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* in Canada (German citizen).
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "includes.h"
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__RCSID("$FreeBSD$");
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#include <sys/types.h>
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#ifdef HAVE_SYS_STAT_H
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# include <sys/stat.h>
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#endif
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#include <sys/resource.h>
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#include <sys/ioctl.h>
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#include <sys/param.h>
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#include <sys/socket.h>
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#include <sys/wait.h>
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#include <ctype.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <netdb.h>
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#ifdef HAVE_PATHS_H
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#include <paths.h>
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#endif
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#include <pwd.h>
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#include <signal.h>
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#include <stdarg.h>
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#include <stddef.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <openssl/evp.h>
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#include <openssl/err.h>
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#include "openbsd-compat/openssl-compat.h"
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#include "openbsd-compat/sys-queue.h"
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#include "xmalloc.h"
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#include "ssh.h"
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#include "ssh1.h"
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#include "ssh2.h"
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#include "canohost.h"
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#include "compat.h"
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#include "cipher.h"
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#include "packet.h"
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#include "buffer.h"
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#include "channels.h"
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#include "key.h"
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#include "authfd.h"
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#include "authfile.h"
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#include "pathnames.h"
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#include "dispatch.h"
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#include "clientloop.h"
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#include "log.h"
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#include "readconf.h"
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#include "sshconnect.h"
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#include "misc.h"
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#include "kex.h"
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#include "mac.h"
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#include "sshpty.h"
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#include "match.h"
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#include "msg.h"
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#include "uidswap.h"
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#include "roaming.h"
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#include "version.h"
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#ifdef ENABLE_PKCS11
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#include "ssh-pkcs11.h"
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#endif
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extern char *__progname;
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/* Saves a copy of argv for setproctitle emulation */
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#ifndef HAVE_SETPROCTITLE
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static char **saved_av;
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#endif
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/* Flag indicating whether debug mode is on. May be set on the command line. */
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int debug_flag = 0;
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/* Flag indicating whether a tty should be requested */
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int tty_flag = 0;
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/* don't exec a shell */
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int no_shell_flag = 0;
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/*
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* Flag indicating that nothing should be read from stdin. This can be set
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* on the command line.
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*/
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int stdin_null_flag = 0;
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/*
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* Flag indicating that the current process should be backgrounded and
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* a new slave launched in the foreground for ControlPersist.
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*/
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int need_controlpersist_detach = 0;
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/* Copies of flags for ControlPersist foreground slave */
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int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty;
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/*
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* Flag indicating that ssh should fork after authentication. This is useful
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* so that the passphrase can be entered manually, and then ssh goes to the
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* background.
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*/
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int fork_after_authentication_flag = 0;
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/* forward stdio to remote host and port */
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char *stdio_forward_host = NULL;
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int stdio_forward_port = 0;
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/*
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* General data structure for command line options and options configurable
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* in configuration files. See readconf.h.
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*/
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Options options;
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/* optional user configfile */
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char *config = NULL;
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/*
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* Name of the host we are connecting to. This is the name given on the
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* command line, or the HostName specified for the user-supplied name in a
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* configuration file.
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*/
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char *host;
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/* socket address the host resolves to */
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struct sockaddr_storage hostaddr;
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/* Private host keys. */
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Sensitive sensitive_data;
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/* Original real UID. */
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uid_t original_real_uid;
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uid_t original_effective_uid;
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/* command to be executed */
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Buffer command;
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/* Should we execute a command or invoke a subsystem? */
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int subsystem_flag = 0;
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/* # of replies received for global requests */
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static int remote_forward_confirms_received = 0;
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/* mux.c */
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extern int muxserver_sock;
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extern u_int muxclient_command;
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/* Prints a help message to the user. This function never returns. */
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static void
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usage(void)
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{
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fprintf(stderr,
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"usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n"
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" [-D [bind_address:]port] [-e escape_char] [-F configfile]\n"
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" [-I pkcs11] [-i identity_file]\n"
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" [-L [bind_address:]port:host:hostport]\n"
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" [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
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" [-R [bind_address:]port:host:hostport] [-S ctl_path]\n"
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" [-W host:port] [-w local_tun[:remote_tun]]\n"
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" [user@]hostname [command]\n"
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);
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exit(255);
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}
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static int ssh_session(void);
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static int ssh_session2(void);
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static void load_public_identity_files(void);
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static void main_sigchld_handler(int);
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/* from muxclient.c */
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void muxclient(const char *);
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void muxserver_listen(void);
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/* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */
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static void
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tilde_expand_paths(char **paths, u_int num_paths)
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{
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u_int i;
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char *cp;
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for (i = 0; i < num_paths; i++) {
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cp = tilde_expand_filename(paths[i], original_real_uid);
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xfree(paths[i]);
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paths[i] = cp;
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}
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}
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/*
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* Main program for the ssh client.
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*/
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int
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main(int ac, char **av)
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{
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int i, r, opt, exit_status, use_syslog;
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char *p, *cp, *line, *argv0, buf[MAXPATHLEN], *host_arg;
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char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV];
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struct stat st;
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struct passwd *pw;
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int dummy, timeout_ms;
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extern int optind, optreset;
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extern char *optarg;
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struct servent *sp;
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Forward fwd;
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/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
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sanitise_stdfd();
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__progname = ssh_get_progname(av[0]);
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#ifndef HAVE_SETPROCTITLE
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/* Prepare for later setproctitle emulation */
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/* Save argv so it isn't clobbered by setproctitle() emulation */
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saved_av = xcalloc(ac + 1, sizeof(*saved_av));
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for (i = 0; i < ac; i++)
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saved_av[i] = xstrdup(av[i]);
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saved_av[i] = NULL;
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compat_init_setproctitle(ac, av);
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av = saved_av;
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#endif
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/*
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* Discard other fds that are hanging around. These can cause problem
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* with backgrounded ssh processes started by ControlPersist.
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*/
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closefrom(STDERR_FILENO + 1);
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/*
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* Save the original real uid. It will be needed later (uid-swapping
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* may clobber the real uid).
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*/
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original_real_uid = getuid();
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original_effective_uid = geteuid();
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/*
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* Use uid-swapping to give up root privileges for the duration of
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* option processing. We will re-instantiate the rights when we are
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* ready to create the privileged port, and will permanently drop
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* them when the port has been created (actually, when the connection
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* has been made, as we may need to create the port several times).
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*/
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PRIV_END;
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#ifdef HAVE_SETRLIMIT
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/* If we are installed setuid root be careful to not drop core. */
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if (original_real_uid != original_effective_uid) {
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struct rlimit rlim;
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rlim.rlim_cur = rlim.rlim_max = 0;
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if (setrlimit(RLIMIT_CORE, &rlim) < 0)
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fatal("setrlimit failed: %.100s", strerror(errno));
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}
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#endif
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/* Get user data. */
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pw = getpwuid(original_real_uid);
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if (!pw) {
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logit("You don't exist, go away!");
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exit(255);
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}
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/* Take a copy of the returned structure. */
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pw = pwcopy(pw);
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/*
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* Set our umask to something reasonable, as some files are created
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* with the default umask. This will make them world-readable but
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* writable only by the owner, which is ok for all files for which we
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* don't set the modes explicitly.
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*/
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umask(022);
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/*
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* Initialize option structure to indicate that no values have been
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* set.
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*/
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initialize_options(&options);
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/* Parse command-line arguments. */
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host = NULL;
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use_syslog = 0;
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argv0 = av[0];
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again:
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while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
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"ACD:F:I:KL:MNO:PR:S:TVw:W:XYy")) != -1) {
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switch (opt) {
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case '1':
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options.protocol = SSH_PROTO_1;
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break;
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case '2':
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options.protocol = SSH_PROTO_2;
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break;
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case '4':
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options.address_family = AF_INET;
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break;
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case '6':
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options.address_family = AF_INET6;
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break;
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case 'n':
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stdin_null_flag = 1;
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break;
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case 'f':
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fork_after_authentication_flag = 1;
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stdin_null_flag = 1;
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break;
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case 'x':
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options.forward_x11 = 0;
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break;
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case 'X':
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options.forward_x11 = 1;
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break;
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case 'y':
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use_syslog = 1;
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break;
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case 'Y':
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options.forward_x11 = 1;
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options.forward_x11_trusted = 1;
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break;
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case 'g':
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options.gateway_ports = 1;
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break;
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case 'O':
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if (stdio_forward_host != NULL)
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fatal("Cannot specify multiplexing "
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"command with -W");
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else if (muxclient_command != 0)
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fatal("Multiplexing command already specified");
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if (strcmp(optarg, "check") == 0)
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muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
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else if (strcmp(optarg, "forward") == 0)
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muxclient_command = SSHMUX_COMMAND_FORWARD;
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else if (strcmp(optarg, "exit") == 0)
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muxclient_command = SSHMUX_COMMAND_TERMINATE;
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else if (strcmp(optarg, "stop") == 0)
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muxclient_command = SSHMUX_COMMAND_STOP;
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else
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fatal("Invalid multiplex command.");
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break;
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case 'P': /* deprecated */
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options.use_privileged_port = 0;
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break;
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case 'a':
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options.forward_agent = 0;
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break;
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case 'A':
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options.forward_agent = 1;
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break;
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case 'k':
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options.gss_deleg_creds = 0;
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break;
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case 'K':
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options.gss_authentication = 1;
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options.gss_deleg_creds = 1;
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break;
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case 'i':
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if (stat(optarg, &st) < 0) {
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fprintf(stderr, "Warning: Identity file %s "
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"not accessible: %s.\n", optarg,
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strerror(errno));
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break;
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}
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if (options.num_identity_files >=
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SSH_MAX_IDENTITY_FILES)
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fatal("Too many identity files specified "
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"(max %d)", SSH_MAX_IDENTITY_FILES);
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options.identity_files[options.num_identity_files++] =
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xstrdup(optarg);
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break;
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case 'I':
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#ifdef ENABLE_PKCS11
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options.pkcs11_provider = xstrdup(optarg);
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#else
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fprintf(stderr, "no support for PKCS#11.\n");
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#endif
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break;
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case 't':
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if (options.request_tty == REQUEST_TTY_YES)
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options.request_tty = REQUEST_TTY_FORCE;
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else
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options.request_tty = REQUEST_TTY_YES;
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break;
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case 'v':
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if (debug_flag == 0) {
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debug_flag = 1;
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options.log_level = SYSLOG_LEVEL_DEBUG1;
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} else {
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if (options.log_level < SYSLOG_LEVEL_DEBUG3)
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options.log_level++;
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break;
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}
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/* FALLTHROUGH */
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case 'V':
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fprintf(stderr, "%s, %s\n",
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SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
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if (opt == 'V')
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exit(0);
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break;
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case 'w':
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if (options.tun_open == -1)
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options.tun_open = SSH_TUNMODE_DEFAULT;
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options.tun_local = a2tun(optarg, &options.tun_remote);
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if (options.tun_local == SSH_TUNID_ERR) {
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fprintf(stderr,
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"Bad tun device '%s'\n", optarg);
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exit(255);
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}
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break;
|
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case 'W':
|
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if (stdio_forward_host != NULL)
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fatal("stdio forward already specified");
|
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if (muxclient_command != 0)
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fatal("Cannot specify stdio forward with -O");
|
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if (parse_forward(&fwd, optarg, 1, 0)) {
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stdio_forward_host = fwd.listen_host;
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stdio_forward_port = fwd.listen_port;
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xfree(fwd.connect_host);
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} else {
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fprintf(stderr,
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"Bad stdio forwarding specification '%s'\n",
|
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optarg);
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exit(255);
|
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}
|
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options.request_tty = REQUEST_TTY_NO;
|
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no_shell_flag = 1;
|
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options.clear_forwardings = 1;
|
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options.exit_on_forward_failure = 1;
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break;
|
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case 'q':
|
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options.log_level = SYSLOG_LEVEL_QUIET;
|
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break;
|
|
case 'e':
|
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if (optarg[0] == '^' && optarg[2] == 0 &&
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(u_char) optarg[1] >= 64 &&
|
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(u_char) optarg[1] < 128)
|
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options.escape_char = (u_char) optarg[1] & 31;
|
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else if (strlen(optarg) == 1)
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options.escape_char = (u_char) optarg[0];
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else if (strcmp(optarg, "none") == 0)
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options.escape_char = SSH_ESCAPECHAR_NONE;
|
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else {
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fprintf(stderr, "Bad escape character '%s'.\n",
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optarg);
|
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exit(255);
|
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}
|
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break;
|
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case 'c':
|
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if (ciphers_valid(optarg)) {
|
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/* SSH2 only */
|
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options.ciphers = xstrdup(optarg);
|
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options.cipher = SSH_CIPHER_INVALID;
|
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} else {
|
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/* SSH1 only */
|
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options.cipher = cipher_number(optarg);
|
|
if (options.cipher == -1) {
|
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fprintf(stderr,
|
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"Unknown cipher type '%s'\n",
|
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optarg);
|
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exit(255);
|
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}
|
|
if (options.cipher == SSH_CIPHER_3DES)
|
|
options.ciphers = "3des-cbc";
|
|
else if (options.cipher == SSH_CIPHER_BLOWFISH)
|
|
options.ciphers = "blowfish-cbc";
|
|
else
|
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options.ciphers = (char *)-1;
|
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}
|
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break;
|
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case 'm':
|
|
if (mac_valid(optarg))
|
|
options.macs = xstrdup(optarg);
|
|
else {
|
|
fprintf(stderr, "Unknown mac type '%s'\n",
|
|
optarg);
|
|
exit(255);
|
|
}
|
|
break;
|
|
case 'M':
|
|
if (options.control_master == SSHCTL_MASTER_YES)
|
|
options.control_master = SSHCTL_MASTER_ASK;
|
|
else
|
|
options.control_master = SSHCTL_MASTER_YES;
|
|
break;
|
|
case 'p':
|
|
options.port = a2port(optarg);
|
|
if (options.port <= 0) {
|
|
fprintf(stderr, "Bad port '%s'\n", optarg);
|
|
exit(255);
|
|
}
|
|
break;
|
|
case 'l':
|
|
options.user = optarg;
|
|
break;
|
|
|
|
case 'L':
|
|
if (parse_forward(&fwd, optarg, 0, 0))
|
|
add_local_forward(&options, &fwd);
|
|
else {
|
|
fprintf(stderr,
|
|
"Bad local forwarding specification '%s'\n",
|
|
optarg);
|
|
exit(255);
|
|
}
|
|
break;
|
|
|
|
case 'R':
|
|
if (parse_forward(&fwd, optarg, 0, 1)) {
|
|
add_remote_forward(&options, &fwd);
|
|
} else {
|
|
fprintf(stderr,
|
|
"Bad remote forwarding specification "
|
|
"'%s'\n", optarg);
|
|
exit(255);
|
|
}
|
|
break;
|
|
|
|
case 'D':
|
|
if (parse_forward(&fwd, optarg, 1, 0)) {
|
|
add_local_forward(&options, &fwd);
|
|
} else {
|
|
fprintf(stderr,
|
|
"Bad dynamic forwarding specification "
|
|
"'%s'\n", optarg);
|
|
exit(255);
|
|
}
|
|
break;
|
|
|
|
case 'C':
|
|
options.compression = 1;
|
|
break;
|
|
case 'N':
|
|
no_shell_flag = 1;
|
|
options.request_tty = REQUEST_TTY_NO;
|
|
break;
|
|
case 'T':
|
|
options.request_tty = REQUEST_TTY_NO;
|
|
#ifdef NONE_CIPHER_ENABLED
|
|
/*
|
|
* Ensure that the user does not try to backdoor a
|
|
* NONE cipher switch on an interactive session by
|
|
* explicitly disabling it if the user asks for a
|
|
* session without a tty.
|
|
*/
|
|
options.none_switch = 0;
|
|
#endif
|
|
break;
|
|
case 'o':
|
|
dummy = 1;
|
|
line = xstrdup(optarg);
|
|
if (process_config_line(&options, host ? host : "",
|
|
line, "command-line", 0, &dummy) != 0)
|
|
exit(255);
|
|
xfree(line);
|
|
break;
|
|
case 's':
|
|
subsystem_flag = 1;
|
|
break;
|
|
case 'S':
|
|
if (options.control_path != NULL)
|
|
free(options.control_path);
|
|
options.control_path = xstrdup(optarg);
|
|
break;
|
|
case 'b':
|
|
options.bind_address = optarg;
|
|
break;
|
|
case 'F':
|
|
config = optarg;
|
|
break;
|
|
default:
|
|
usage();
|
|
}
|
|
}
|
|
|
|
ac -= optind;
|
|
av += optind;
|
|
|
|
if (ac > 0 && !host) {
|
|
if (strrchr(*av, '@')) {
|
|
p = xstrdup(*av);
|
|
cp = strrchr(p, '@');
|
|
if (cp == NULL || cp == p)
|
|
usage();
|
|
options.user = p;
|
|
*cp = '\0';
|
|
host = ++cp;
|
|
} else
|
|
host = *av;
|
|
if (ac > 1) {
|
|
optind = optreset = 1;
|
|
goto again;
|
|
}
|
|
ac--, av++;
|
|
}
|
|
|
|
/* Check that we got a host name. */
|
|
if (!host)
|
|
usage();
|
|
|
|
OpenSSL_add_all_algorithms();
|
|
ERR_load_crypto_strings();
|
|
|
|
/* Initialize the command to execute on remote host. */
|
|
buffer_init(&command);
|
|
|
|
if (options.request_tty == REQUEST_TTY_YES ||
|
|
options.request_tty == REQUEST_TTY_FORCE)
|
|
tty_flag = 1;
|
|
|
|
/*
|
|
* Save the command to execute on the remote host in a buffer. There
|
|
* is no limit on the length of the command, except by the maximum
|
|
* packet size. Also sets the tty flag if there is no command.
|
|
*/
|
|
if (!ac) {
|
|
/* No command specified - execute shell on a tty. */
|
|
tty_flag = options.request_tty != REQUEST_TTY_NO;
|
|
if (subsystem_flag) {
|
|
fprintf(stderr,
|
|
"You must specify a subsystem to invoke.\n");
|
|
usage();
|
|
}
|
|
} else {
|
|
/* A command has been specified. Store it into the buffer. */
|
|
for (i = 0; i < ac; i++) {
|
|
if (i)
|
|
buffer_append(&command, " ", 1);
|
|
buffer_append(&command, av[i], strlen(av[i]));
|
|
}
|
|
}
|
|
|
|
/* Cannot fork to background if no command. */
|
|
if (fork_after_authentication_flag && buffer_len(&command) == 0 &&
|
|
!no_shell_flag)
|
|
fatal("Cannot fork into background without a command "
|
|
"to execute.");
|
|
|
|
/* Allocate a tty by default if no command specified. */
|
|
if (buffer_len(&command) == 0)
|
|
tty_flag = options.request_tty != REQUEST_TTY_NO;
|
|
|
|
/* Force no tty */
|
|
if (options.request_tty == REQUEST_TTY_NO || muxclient_command != 0)
|
|
tty_flag = 0;
|
|
/* Do not allocate a tty if stdin is not a tty. */
|
|
if ((!isatty(fileno(stdin)) || stdin_null_flag) &&
|
|
options.request_tty != REQUEST_TTY_FORCE) {
|
|
if (tty_flag)
|
|
logit("Pseudo-terminal will not be allocated because "
|
|
"stdin is not a terminal.");
|
|
tty_flag = 0;
|
|
}
|
|
|
|
/*
|
|
* Initialize "log" output. Since we are the client all output
|
|
* actually goes to stderr.
|
|
*/
|
|
log_init(argv0,
|
|
options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
|
|
SYSLOG_FACILITY_USER, !use_syslog);
|
|
|
|
/*
|
|
* Read per-user configuration file. Ignore the system wide config
|
|
* file if the user specifies a config file on the command line.
|
|
*/
|
|
if (config != NULL) {
|
|
if (!read_config_file(config, host, &options, 0))
|
|
fatal("Can't open user config file %.100s: "
|
|
"%.100s", config, strerror(errno));
|
|
} else {
|
|
r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir,
|
|
_PATH_SSH_USER_CONFFILE);
|
|
if (r > 0 && (size_t)r < sizeof(buf))
|
|
(void)read_config_file(buf, host, &options, 1);
|
|
|
|
/* Read systemwide configuration file after user config. */
|
|
(void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
|
|
&options, 0);
|
|
}
|
|
|
|
/* Fill configuration defaults. */
|
|
fill_default_options(&options);
|
|
|
|
channel_set_af(options.address_family);
|
|
|
|
/* reinit */
|
|
log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog);
|
|
|
|
seed_rng();
|
|
|
|
if (options.user == NULL)
|
|
options.user = xstrdup(pw->pw_name);
|
|
|
|
/* Get default port if port has not been set. */
|
|
if (options.port == 0) {
|
|
sp = getservbyname(SSH_SERVICE_NAME, "tcp");
|
|
options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
|
|
}
|
|
|
|
/* preserve host name given on command line for %n expansion */
|
|
host_arg = host;
|
|
if (options.hostname != NULL) {
|
|
host = percent_expand(options.hostname,
|
|
"h", host, (char *)NULL);
|
|
}
|
|
|
|
if (gethostname(thishost, sizeof(thishost)) == -1)
|
|
fatal("gethostname: %s", strerror(errno));
|
|
strlcpy(shorthost, thishost, sizeof(shorthost));
|
|
shorthost[strcspn(thishost, ".")] = '\0';
|
|
snprintf(portstr, sizeof(portstr), "%d", options.port);
|
|
|
|
if (options.local_command != NULL) {
|
|
debug3("expanding LocalCommand: %s", options.local_command);
|
|
cp = options.local_command;
|
|
options.local_command = percent_expand(cp, "d", pw->pw_dir,
|
|
"h", host, "l", thishost, "n", host_arg, "r", options.user,
|
|
"p", portstr, "u", pw->pw_name, "L", shorthost,
|
|
(char *)NULL);
|
|
debug3("expanded LocalCommand: %s", options.local_command);
|
|
xfree(cp);
|
|
}
|
|
|
|
/* Find canonic host name. */
|
|
if (strchr(host, '.') == 0) {
|
|
struct addrinfo hints;
|
|
struct addrinfo *ai = NULL;
|
|
int errgai;
|
|
memset(&hints, 0, sizeof(hints));
|
|
hints.ai_family = options.address_family;
|
|
hints.ai_flags = AI_CANONNAME;
|
|
hints.ai_socktype = SOCK_STREAM;
|
|
errgai = getaddrinfo(host, NULL, &hints, &ai);
|
|
if (errgai == 0) {
|
|
if (ai->ai_canonname != NULL)
|
|
host = xstrdup(ai->ai_canonname);
|
|
freeaddrinfo(ai);
|
|
}
|
|
}
|
|
|
|
/* force lowercase for hostkey matching */
|
|
if (options.host_key_alias != NULL) {
|
|
for (p = options.host_key_alias; *p; p++)
|
|
if (isupper(*p))
|
|
*p = (char)tolower(*p);
|
|
}
|
|
|
|
if (options.proxy_command != NULL &&
|
|
strcmp(options.proxy_command, "none") == 0) {
|
|
xfree(options.proxy_command);
|
|
options.proxy_command = NULL;
|
|
}
|
|
if (options.control_path != NULL &&
|
|
strcmp(options.control_path, "none") == 0) {
|
|
xfree(options.control_path);
|
|
options.control_path = NULL;
|
|
}
|
|
|
|
if (options.control_path != NULL) {
|
|
cp = tilde_expand_filename(options.control_path,
|
|
original_real_uid);
|
|
xfree(options.control_path);
|
|
options.control_path = percent_expand(cp, "h", host,
|
|
"l", thishost, "n", host_arg, "r", options.user,
|
|
"p", portstr, "u", pw->pw_name, "L", shorthost,
|
|
(char *)NULL);
|
|
xfree(cp);
|
|
}
|
|
if (muxclient_command != 0 && options.control_path == NULL)
|
|
fatal("No ControlPath specified for \"-O\" command");
|
|
if (options.control_path != NULL)
|
|
muxclient(options.control_path);
|
|
|
|
timeout_ms = options.connection_timeout * 1000;
|
|
|
|
/* Open a connection to the remote host. */
|
|
if (ssh_connect(host, &hostaddr, options.port,
|
|
options.address_family, options.connection_attempts, &timeout_ms,
|
|
options.tcp_keep_alive,
|
|
#ifdef HAVE_CYGWIN
|
|
options.use_privileged_port,
|
|
#else
|
|
original_effective_uid == 0 && options.use_privileged_port,
|
|
#endif
|
|
options.proxy_command) != 0)
|
|
exit(255);
|
|
|
|
if (timeout_ms > 0)
|
|
debug3("timeout: %d ms remain after connect", timeout_ms);
|
|
|
|
/*
|
|
* If we successfully made the connection, load the host private key
|
|
* in case we will need it later for combined rsa-rhosts
|
|
* authentication. This must be done before releasing extra
|
|
* privileges, because the file is only readable by root.
|
|
* If we cannot access the private keys, load the public keys
|
|
* instead and try to execute the ssh-keysign helper instead.
|
|
*/
|
|
sensitive_data.nkeys = 0;
|
|
sensitive_data.keys = NULL;
|
|
sensitive_data.external_keysign = 0;
|
|
if (options.rhosts_rsa_authentication ||
|
|
options.hostbased_authentication) {
|
|
sensitive_data.nkeys = 7;
|
|
sensitive_data.keys = xcalloc(sensitive_data.nkeys,
|
|
sizeof(Key));
|
|
for (i = 0; i < sensitive_data.nkeys; i++)
|
|
sensitive_data.keys[i] = NULL;
|
|
|
|
PRIV_START;
|
|
sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
|
|
_PATH_HOST_KEY_FILE, "", NULL, NULL);
|
|
sensitive_data.keys[1] = key_load_private_cert(KEY_DSA,
|
|
_PATH_HOST_DSA_KEY_FILE, "", NULL);
|
|
#ifdef OPENSSL_HAS_ECC
|
|
sensitive_data.keys[2] = key_load_private_cert(KEY_ECDSA,
|
|
_PATH_HOST_ECDSA_KEY_FILE, "", NULL);
|
|
#endif
|
|
sensitive_data.keys[3] = key_load_private_cert(KEY_RSA,
|
|
_PATH_HOST_RSA_KEY_FILE, "", NULL);
|
|
sensitive_data.keys[4] = key_load_private_type(KEY_DSA,
|
|
_PATH_HOST_DSA_KEY_FILE, "", NULL, NULL);
|
|
#ifdef OPENSSL_HAS_ECC
|
|
sensitive_data.keys[5] = key_load_private_type(KEY_ECDSA,
|
|
_PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL);
|
|
#endif
|
|
sensitive_data.keys[6] = key_load_private_type(KEY_RSA,
|
|
_PATH_HOST_RSA_KEY_FILE, "", NULL, NULL);
|
|
PRIV_END;
|
|
|
|
if (options.hostbased_authentication == 1 &&
|
|
sensitive_data.keys[0] == NULL &&
|
|
sensitive_data.keys[4] == NULL &&
|
|
sensitive_data.keys[5] == NULL &&
|
|
sensitive_data.keys[6] == NULL) {
|
|
sensitive_data.keys[1] = key_load_cert(
|
|
_PATH_HOST_DSA_KEY_FILE);
|
|
#ifdef OPENSSL_HAS_ECC
|
|
sensitive_data.keys[2] = key_load_cert(
|
|
_PATH_HOST_ECDSA_KEY_FILE);
|
|
#endif
|
|
sensitive_data.keys[3] = key_load_cert(
|
|
_PATH_HOST_RSA_KEY_FILE);
|
|
sensitive_data.keys[4] = key_load_public(
|
|
_PATH_HOST_DSA_KEY_FILE, NULL);
|
|
#ifdef OPENSSL_HAS_ECC
|
|
sensitive_data.keys[5] = key_load_public(
|
|
_PATH_HOST_ECDSA_KEY_FILE, NULL);
|
|
#endif
|
|
sensitive_data.keys[6] = key_load_public(
|
|
_PATH_HOST_RSA_KEY_FILE, NULL);
|
|
sensitive_data.external_keysign = 1;
|
|
}
|
|
}
|
|
/*
|
|
* Get rid of any extra privileges that we may have. We will no
|
|
* longer need them. Also, extra privileges could make it very hard
|
|
* to read identity files and other non-world-readable files from the
|
|
* user's home directory if it happens to be on a NFS volume where
|
|
* root is mapped to nobody.
|
|
*/
|
|
if (original_effective_uid == 0) {
|
|
PRIV_START;
|
|
permanently_set_uid(pw);
|
|
}
|
|
|
|
/*
|
|
* Now that we are back to our own permissions, create ~/.ssh
|
|
* directory if it doesn't already exist.
|
|
*/
|
|
r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir,
|
|
strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
|
|
if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) {
|
|
#ifdef WITH_SELINUX
|
|
ssh_selinux_setfscreatecon(buf);
|
|
#endif
|
|
if (mkdir(buf, 0700) < 0)
|
|
error("Could not create directory '%.200s'.", buf);
|
|
#ifdef WITH_SELINUX
|
|
ssh_selinux_setfscreatecon(NULL);
|
|
#endif
|
|
}
|
|
/* load options.identity_files */
|
|
load_public_identity_files();
|
|
|
|
/* Expand ~ in known host file names. */
|
|
tilde_expand_paths(options.system_hostfiles,
|
|
options.num_system_hostfiles);
|
|
tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles);
|
|
|
|
signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
|
|
signal(SIGCHLD, main_sigchld_handler);
|
|
|
|
/* Log into the remote system. Never returns if the login fails. */
|
|
ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr,
|
|
options.port, pw, timeout_ms);
|
|
|
|
if (packet_connection_is_on_socket()) {
|
|
verbose("Authenticated to %s ([%s]:%d).", host,
|
|
get_remote_ipaddr(), get_remote_port());
|
|
} else {
|
|
verbose("Authenticated to %s (via proxy).", host);
|
|
}
|
|
|
|
/* We no longer need the private host keys. Clear them now. */
|
|
if (sensitive_data.nkeys != 0) {
|
|
for (i = 0; i < sensitive_data.nkeys; i++) {
|
|
if (sensitive_data.keys[i] != NULL) {
|
|
/* Destroys contents safely */
|
|
debug3("clear hostkey %d", i);
|
|
key_free(sensitive_data.keys[i]);
|
|
sensitive_data.keys[i] = NULL;
|
|
}
|
|
}
|
|
xfree(sensitive_data.keys);
|
|
}
|
|
for (i = 0; i < options.num_identity_files; i++) {
|
|
if (options.identity_files[i]) {
|
|
xfree(options.identity_files[i]);
|
|
options.identity_files[i] = NULL;
|
|
}
|
|
if (options.identity_keys[i]) {
|
|
key_free(options.identity_keys[i]);
|
|
options.identity_keys[i] = NULL;
|
|
}
|
|
}
|
|
|
|
exit_status = compat20 ? ssh_session2() : ssh_session();
|
|
packet_close();
|
|
|
|
if (options.control_path != NULL && muxserver_sock != -1)
|
|
unlink(options.control_path);
|
|
|
|
/* Kill ProxyCommand if it is running. */
|
|
ssh_kill_proxy_command();
|
|
|
|
return exit_status;
|
|
}
|
|
|
|
static void
|
|
control_persist_detach(void)
|
|
{
|
|
pid_t pid;
|
|
int devnull;
|
|
|
|
debug("%s: backgrounding master process", __func__);
|
|
|
|
/*
|
|
* master (current process) into the background, and make the
|
|
* foreground process a client of the backgrounded master.
|
|
*/
|
|
switch ((pid = fork())) {
|
|
case -1:
|
|
fatal("%s: fork: %s", __func__, strerror(errno));
|
|
case 0:
|
|
/* Child: master process continues mainloop */
|
|
break;
|
|
default:
|
|
/* Parent: set up mux slave to connect to backgrounded master */
|
|
debug2("%s: background process is %ld", __func__, (long)pid);
|
|
stdin_null_flag = ostdin_null_flag;
|
|
options.request_tty = orequest_tty;
|
|
tty_flag = otty_flag;
|
|
close(muxserver_sock);
|
|
muxserver_sock = -1;
|
|
options.control_master = SSHCTL_MASTER_NO;
|
|
muxclient(options.control_path);
|
|
/* muxclient() doesn't return on success. */
|
|
fatal("Failed to connect to new control master");
|
|
}
|
|
if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
|
|
error("%s: open(\"/dev/null\"): %s", __func__,
|
|
strerror(errno));
|
|
} else {
|
|
if (dup2(devnull, STDIN_FILENO) == -1 ||
|
|
dup2(devnull, STDOUT_FILENO) == -1)
|
|
error("%s: dup2: %s", __func__, strerror(errno));
|
|
if (devnull > STDERR_FILENO)
|
|
close(devnull);
|
|
}
|
|
setproctitle("%s [mux]", options.control_path);
|
|
}
|
|
|
|
/* Do fork() after authentication. Used by "ssh -f" */
|
|
static void
|
|
fork_postauth(void)
|
|
{
|
|
if (need_controlpersist_detach)
|
|
control_persist_detach();
|
|
debug("forking to background");
|
|
fork_after_authentication_flag = 0;
|
|
if (daemon(1, 1) < 0)
|
|
fatal("daemon() failed: %.200s", strerror(errno));
|
|
}
|
|
|
|
/* Callback for remote forward global requests */
|
|
static void
|
|
ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
|
|
{
|
|
Forward *rfwd = (Forward *)ctxt;
|
|
|
|
/* XXX verbose() on failure? */
|
|
debug("remote forward %s for: listen %d, connect %s:%d",
|
|
type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
|
|
rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
|
|
if (type == SSH2_MSG_REQUEST_SUCCESS && rfwd->listen_port == 0) {
|
|
rfwd->allocated_port = packet_get_int();
|
|
logit("Allocated port %u for remote forward to %s:%d",
|
|
rfwd->allocated_port,
|
|
rfwd->connect_host, rfwd->connect_port);
|
|
}
|
|
|
|
if (type == SSH2_MSG_REQUEST_FAILURE) {
|
|
if (options.exit_on_forward_failure)
|
|
fatal("Error: remote port forwarding failed for "
|
|
"listen port %d", rfwd->listen_port);
|
|
else
|
|
logit("Warning: remote port forwarding failed for "
|
|
"listen port %d", rfwd->listen_port);
|
|
}
|
|
if (++remote_forward_confirms_received == options.num_remote_forwards) {
|
|
debug("All remote forwarding requests processed");
|
|
if (fork_after_authentication_flag)
|
|
fork_postauth();
|
|
}
|
|
}
|
|
|
|
static void
|
|
client_cleanup_stdio_fwd(int id, void *arg)
|
|
{
|
|
debug("stdio forwarding: done");
|
|
cleanup_exit(0);
|
|
}
|
|
|
|
static int
|
|
client_setup_stdio_fwd(const char *host_to_connect, u_short port_to_connect)
|
|
{
|
|
Channel *c;
|
|
int in, out;
|
|
|
|
debug3("client_setup_stdio_fwd %s:%d", host_to_connect,
|
|
port_to_connect);
|
|
|
|
in = dup(STDIN_FILENO);
|
|
out = dup(STDOUT_FILENO);
|
|
if (in < 0 || out < 0)
|
|
fatal("channel_connect_stdio_fwd: dup() in/out failed");
|
|
|
|
if ((c = channel_connect_stdio_fwd(host_to_connect, port_to_connect,
|
|
in, out)) == NULL)
|
|
return 0;
|
|
channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0);
|
|
return 1;
|
|
}
|
|
|
|
static void
|
|
ssh_init_forwarding(void)
|
|
{
|
|
int success = 0;
|
|
int i;
|
|
|
|
if (stdio_forward_host != NULL) {
|
|
if (!compat20) {
|
|
fatal("stdio forwarding require Protocol 2");
|
|
}
|
|
if (!client_setup_stdio_fwd(stdio_forward_host,
|
|
stdio_forward_port))
|
|
fatal("Failed to connect in stdio forward mode.");
|
|
}
|
|
|
|
/* Initiate local TCP/IP port forwardings. */
|
|
for (i = 0; i < options.num_local_forwards; i++) {
|
|
debug("Local connections to %.200s:%d forwarded to remote "
|
|
"address %.200s:%d",
|
|
(options.local_forwards[i].listen_host == NULL) ?
|
|
(options.gateway_ports ? "*" : "LOCALHOST") :
|
|
options.local_forwards[i].listen_host,
|
|
options.local_forwards[i].listen_port,
|
|
options.local_forwards[i].connect_host,
|
|
options.local_forwards[i].connect_port);
|
|
success += channel_setup_local_fwd_listener(
|
|
options.local_forwards[i].listen_host,
|
|
options.local_forwards[i].listen_port,
|
|
options.local_forwards[i].connect_host,
|
|
options.local_forwards[i].connect_port,
|
|
options.gateway_ports);
|
|
}
|
|
if (i > 0 && success != i && options.exit_on_forward_failure)
|
|
fatal("Could not request local forwarding.");
|
|
if (i > 0 && success == 0)
|
|
error("Could not request local forwarding.");
|
|
|
|
/* Initiate remote TCP/IP port forwardings. */
|
|
for (i = 0; i < options.num_remote_forwards; i++) {
|
|
debug("Remote connections from %.200s:%d forwarded to "
|
|
"local address %.200s:%d",
|
|
(options.remote_forwards[i].listen_host == NULL) ?
|
|
"LOCALHOST" : options.remote_forwards[i].listen_host,
|
|
options.remote_forwards[i].listen_port,
|
|
options.remote_forwards[i].connect_host,
|
|
options.remote_forwards[i].connect_port);
|
|
if (channel_request_remote_forwarding(
|
|
options.remote_forwards[i].listen_host,
|
|
options.remote_forwards[i].listen_port,
|
|
options.remote_forwards[i].connect_host,
|
|
options.remote_forwards[i].connect_port) < 0) {
|
|
if (options.exit_on_forward_failure)
|
|
fatal("Could not request remote forwarding.");
|
|
else
|
|
logit("Warning: Could not request remote "
|
|
"forwarding.");
|
|
}
|
|
client_register_global_confirm(ssh_confirm_remote_forward,
|
|
&options.remote_forwards[i]);
|
|
}
|
|
|
|
/* Initiate tunnel forwarding. */
|
|
if (options.tun_open != SSH_TUNMODE_NO) {
|
|
if (client_request_tun_fwd(options.tun_open,
|
|
options.tun_local, options.tun_remote) == -1) {
|
|
if (options.exit_on_forward_failure)
|
|
fatal("Could not request tunnel forwarding.");
|
|
else
|
|
error("Could not request tunnel forwarding.");
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
check_agent_present(void)
|
|
{
|
|
if (options.forward_agent) {
|
|
/* Clear agent forwarding if we don't have an agent. */
|
|
if (!ssh_agent_present())
|
|
options.forward_agent = 0;
|
|
}
|
|
}
|
|
|
|
static int
|
|
ssh_session(void)
|
|
{
|
|
int type;
|
|
int interactive = 0;
|
|
int have_tty = 0;
|
|
struct winsize ws;
|
|
char *cp;
|
|
const char *display;
|
|
|
|
/* Enable compression if requested. */
|
|
if (options.compression) {
|
|
debug("Requesting compression at level %d.",
|
|
options.compression_level);
|
|
|
|
if (options.compression_level < 1 ||
|
|
options.compression_level > 9)
|
|
fatal("Compression level must be from 1 (fast) to "
|
|
"9 (slow, best).");
|
|
|
|
/* Send the request. */
|
|
packet_start(SSH_CMSG_REQUEST_COMPRESSION);
|
|
packet_put_int(options.compression_level);
|
|
packet_send();
|
|
packet_write_wait();
|
|
type = packet_read();
|
|
if (type == SSH_SMSG_SUCCESS)
|
|
packet_start_compression(options.compression_level);
|
|
else if (type == SSH_SMSG_FAILURE)
|
|
logit("Warning: Remote host refused compression.");
|
|
else
|
|
packet_disconnect("Protocol error waiting for "
|
|
"compression response.");
|
|
}
|
|
/* Allocate a pseudo tty if appropriate. */
|
|
if (tty_flag) {
|
|
debug("Requesting pty.");
|
|
|
|
/* Start the packet. */
|
|
packet_start(SSH_CMSG_REQUEST_PTY);
|
|
|
|
/* Store TERM in the packet. There is no limit on the
|
|
length of the string. */
|
|
cp = getenv("TERM");
|
|
if (!cp)
|
|
cp = "";
|
|
packet_put_cstring(cp);
|
|
|
|
/* Store window size in the packet. */
|
|
if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
|
|
memset(&ws, 0, sizeof(ws));
|
|
packet_put_int((u_int)ws.ws_row);
|
|
packet_put_int((u_int)ws.ws_col);
|
|
packet_put_int((u_int)ws.ws_xpixel);
|
|
packet_put_int((u_int)ws.ws_ypixel);
|
|
|
|
/* Store tty modes in the packet. */
|
|
tty_make_modes(fileno(stdin), NULL);
|
|
|
|
/* Send the packet, and wait for it to leave. */
|
|
packet_send();
|
|
packet_write_wait();
|
|
|
|
/* Read response from the server. */
|
|
type = packet_read();
|
|
if (type == SSH_SMSG_SUCCESS) {
|
|
interactive = 1;
|
|
have_tty = 1;
|
|
} else if (type == SSH_SMSG_FAILURE)
|
|
logit("Warning: Remote host failed or refused to "
|
|
"allocate a pseudo tty.");
|
|
else
|
|
packet_disconnect("Protocol error waiting for pty "
|
|
"request response.");
|
|
}
|
|
/* Request X11 forwarding if enabled and DISPLAY is set. */
|
|
display = getenv("DISPLAY");
|
|
if (options.forward_x11 && display != NULL) {
|
|
char *proto, *data;
|
|
/* Get reasonable local authentication information. */
|
|
client_x11_get_proto(display, options.xauth_location,
|
|
options.forward_x11_trusted,
|
|
options.forward_x11_timeout,
|
|
&proto, &data);
|
|
/* Request forwarding with authentication spoofing. */
|
|
debug("Requesting X11 forwarding with authentication "
|
|
"spoofing.");
|
|
x11_request_forwarding_with_spoofing(0, display, proto,
|
|
data, 0);
|
|
/* Read response from the server. */
|
|
type = packet_read();
|
|
if (type == SSH_SMSG_SUCCESS) {
|
|
interactive = 1;
|
|
} else if (type == SSH_SMSG_FAILURE) {
|
|
logit("Warning: Remote host denied X11 forwarding.");
|
|
} else {
|
|
packet_disconnect("Protocol error waiting for X11 "
|
|
"forwarding");
|
|
}
|
|
}
|
|
/* Tell the packet module whether this is an interactive session. */
|
|
packet_set_interactive(interactive,
|
|
options.ip_qos_interactive, options.ip_qos_bulk);
|
|
|
|
/* Request authentication agent forwarding if appropriate. */
|
|
check_agent_present();
|
|
|
|
if (options.forward_agent) {
|
|
debug("Requesting authentication agent forwarding.");
|
|
auth_request_forwarding();
|
|
|
|
/* Read response from the server. */
|
|
type = packet_read();
|
|
packet_check_eom();
|
|
if (type != SSH_SMSG_SUCCESS)
|
|
logit("Warning: Remote host denied authentication agent forwarding.");
|
|
}
|
|
|
|
/* Initiate port forwardings. */
|
|
ssh_init_forwarding();
|
|
|
|
/* Execute a local command */
|
|
if (options.local_command != NULL &&
|
|
options.permit_local_command)
|
|
ssh_local_cmd(options.local_command);
|
|
|
|
/*
|
|
* If requested and we are not interested in replies to remote
|
|
* forwarding requests, then let ssh continue in the background.
|
|
*/
|
|
if (fork_after_authentication_flag) {
|
|
if (options.exit_on_forward_failure &&
|
|
options.num_remote_forwards > 0) {
|
|
debug("deferring postauth fork until remote forward "
|
|
"confirmation received");
|
|
} else
|
|
fork_postauth();
|
|
}
|
|
|
|
/*
|
|
* If a command was specified on the command line, execute the
|
|
* command now. Otherwise request the server to start a shell.
|
|
*/
|
|
if (buffer_len(&command) > 0) {
|
|
int len = buffer_len(&command);
|
|
if (len > 900)
|
|
len = 900;
|
|
debug("Sending command: %.*s", len,
|
|
(u_char *)buffer_ptr(&command));
|
|
packet_start(SSH_CMSG_EXEC_CMD);
|
|
packet_put_string(buffer_ptr(&command), buffer_len(&command));
|
|
packet_send();
|
|
packet_write_wait();
|
|
} else {
|
|
debug("Requesting shell.");
|
|
packet_start(SSH_CMSG_EXEC_SHELL);
|
|
packet_send();
|
|
packet_write_wait();
|
|
}
|
|
|
|
/* Enter the interactive session. */
|
|
return client_loop(have_tty, tty_flag ?
|
|
options.escape_char : SSH_ESCAPECHAR_NONE, 0);
|
|
}
|
|
|
|
/* request pty/x11/agent/tcpfwd/shell for channel */
|
|
static void
|
|
ssh_session2_setup(int id, int success, void *arg)
|
|
{
|
|
extern char **environ;
|
|
const char *display;
|
|
int interactive = tty_flag;
|
|
|
|
if (!success)
|
|
return; /* No need for error message, channels code sens one */
|
|
|
|
display = getenv("DISPLAY");
|
|
if (options.forward_x11 && display != NULL) {
|
|
char *proto, *data;
|
|
/* Get reasonable local authentication information. */
|
|
client_x11_get_proto(display, options.xauth_location,
|
|
options.forward_x11_trusted,
|
|
options.forward_x11_timeout, &proto, &data);
|
|
/* Request forwarding with authentication spoofing. */
|
|
debug("Requesting X11 forwarding with authentication "
|
|
"spoofing.");
|
|
x11_request_forwarding_with_spoofing(id, display, proto,
|
|
data, 1);
|
|
client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN);
|
|
/* XXX exit_on_forward_failure */
|
|
interactive = 1;
|
|
}
|
|
|
|
check_agent_present();
|
|
if (options.forward_agent) {
|
|
debug("Requesting authentication agent forwarding.");
|
|
channel_request_start(id, "auth-agent-req@openssh.com", 0);
|
|
packet_send();
|
|
}
|
|
|
|
client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
|
|
NULL, fileno(stdin), &command, environ);
|
|
}
|
|
|
|
/* open new channel for a session */
|
|
static int
|
|
ssh_session2_open(void)
|
|
{
|
|
Channel *c;
|
|
int window, packetmax, in, out, err;
|
|
|
|
if (stdin_null_flag) {
|
|
in = open(_PATH_DEVNULL, O_RDONLY);
|
|
} else {
|
|
in = dup(STDIN_FILENO);
|
|
}
|
|
out = dup(STDOUT_FILENO);
|
|
err = dup(STDERR_FILENO);
|
|
|
|
if (in < 0 || out < 0 || err < 0)
|
|
fatal("dup() in/out/err failed");
|
|
|
|
/* enable nonblocking unless tty */
|
|
if (!isatty(in))
|
|
set_nonblock(in);
|
|
if (!isatty(out))
|
|
set_nonblock(out);
|
|
if (!isatty(err))
|
|
set_nonblock(err);
|
|
|
|
/*
|
|
* We need to check to see what to do about buffer sizes here.
|
|
* - In an HPN to non-HPN connection we want to limit the window size to
|
|
* something reasonable in case the far side has the large window bug.
|
|
* - In an HPN to HPN connection we want to use the max window size but
|
|
* allow the user to override it.
|
|
* - Lastly if HPN is disabled then use the ssh standard window size.
|
|
*
|
|
* We cannot just do a getsockopt() here and set the ssh window to that
|
|
* as in case of autotuning of socket buffers the window would get stuck
|
|
* at the initial buffer size, generally less than 96k. Therefore we
|
|
* need to set the maximum ssh window size to the maximum HPN buffer
|
|
* size unless the user has set TcpRcvBufPoll to no. In that case we
|
|
* can just set the window to the minimum of HPN buffer size and TCP
|
|
* receive buffer size.
|
|
*/
|
|
if (tty_flag)
|
|
options.hpn_buffer_size = CHAN_SES_WINDOW_DEFAULT;
|
|
else
|
|
options.hpn_buffer_size = CHAN_HPN_MIN_WINDOW_DEFAULT;
|
|
|
|
if (datafellows & SSH_BUG_LARGEWINDOW) {
|
|
debug("HPN to Non-HPN Connection");
|
|
} else if (options.tcp_rcv_buf_poll <= 0) {
|
|
sock_get_rcvbuf(&options.hpn_buffer_size, 0);
|
|
debug("HPNBufferSize set to TCP RWIN: %d",
|
|
options.hpn_buffer_size);
|
|
} else if (options.tcp_rcv_buf > 0) {
|
|
sock_get_rcvbuf(&options.hpn_buffer_size,
|
|
options.tcp_rcv_buf);
|
|
debug("HPNBufferSize set to user TCPRcvBuf: %d",
|
|
options.hpn_buffer_size);
|
|
}
|
|
debug("Final hpn_buffer_size = %d", options.hpn_buffer_size);
|
|
channel_set_hpn(options.hpn_disabled, options.hpn_buffer_size);
|
|
window = options.hpn_buffer_size;
|
|
|
|
packetmax = CHAN_SES_PACKET_DEFAULT;
|
|
if (tty_flag) {
|
|
window = CHAN_SES_WINDOW_DEFAULT;
|
|
window >>= 1;
|
|
packetmax >>= 1;
|
|
}
|
|
c = channel_new(
|
|
"session", SSH_CHANNEL_OPENING, in, out, err,
|
|
window, packetmax, CHAN_EXTENDED_WRITE,
|
|
"client-session", /*nonblock*/0);
|
|
if (!options.hpn_disabled && options.tcp_rcv_buf_poll > 0) {
|
|
c->dynamic_window = 1;
|
|
debug("Enabled Dynamic Window Scaling\n");
|
|
}
|
|
debug3("ssh_session2_open: channel_new: %d", c->self);
|
|
|
|
channel_send_open(c->self);
|
|
if (!no_shell_flag)
|
|
channel_register_open_confirm(c->self,
|
|
ssh_session2_setup, NULL);
|
|
|
|
return c->self;
|
|
}
|
|
|
|
static int
|
|
ssh_session2(void)
|
|
{
|
|
int id = -1;
|
|
|
|
/* XXX should be pre-session */
|
|
ssh_init_forwarding();
|
|
|
|
/* Start listening for multiplex clients */
|
|
muxserver_listen();
|
|
|
|
/*
|
|
* If we are in control persist mode, then prepare to background
|
|
* ourselves and have a foreground client attach as a control
|
|
* slave. NB. we must save copies of the flags that we override for
|
|
* the backgrounding, since we defer attachment of the slave until
|
|
* after the connection is fully established (in particular,
|
|
* async rfwd replies have been received for ExitOnForwardFailure).
|
|
*/
|
|
if (options.control_persist && muxserver_sock != -1) {
|
|
ostdin_null_flag = stdin_null_flag;
|
|
ono_shell_flag = no_shell_flag;
|
|
orequest_tty = options.request_tty;
|
|
otty_flag = tty_flag;
|
|
stdin_null_flag = 1;
|
|
no_shell_flag = 1;
|
|
tty_flag = 0;
|
|
if (!fork_after_authentication_flag)
|
|
need_controlpersist_detach = 1;
|
|
fork_after_authentication_flag = 1;
|
|
}
|
|
|
|
if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
|
|
id = ssh_session2_open();
|
|
|
|
/* If we don't expect to open a new session, then disallow it */
|
|
if (options.control_master == SSHCTL_MASTER_NO &&
|
|
(datafellows & SSH_NEW_OPENSSH)) {
|
|
debug("Requesting no-more-sessions@openssh.com");
|
|
packet_start(SSH2_MSG_GLOBAL_REQUEST);
|
|
packet_put_cstring("no-more-sessions@openssh.com");
|
|
packet_put_char(0);
|
|
packet_send();
|
|
}
|
|
|
|
/* Execute a local command */
|
|
if (options.local_command != NULL &&
|
|
options.permit_local_command)
|
|
ssh_local_cmd(options.local_command);
|
|
|
|
/*
|
|
* If requested and we are not interested in replies to remote
|
|
* forwarding requests, then let ssh continue in the background.
|
|
*/
|
|
if (fork_after_authentication_flag) {
|
|
if (options.exit_on_forward_failure &&
|
|
options.num_remote_forwards > 0) {
|
|
debug("deferring postauth fork until remote forward "
|
|
"confirmation received");
|
|
} else
|
|
fork_postauth();
|
|
}
|
|
|
|
if (options.use_roaming)
|
|
request_roaming();
|
|
|
|
return client_loop(tty_flag, tty_flag ?
|
|
options.escape_char : SSH_ESCAPECHAR_NONE, id);
|
|
}
|
|
|
|
static void
|
|
load_public_identity_files(void)
|
|
{
|
|
char *filename, *cp, thishost[NI_MAXHOST];
|
|
char *pwdir = NULL, *pwname = NULL;
|
|
int i = 0;
|
|
Key *public;
|
|
struct passwd *pw;
|
|
u_int n_ids;
|
|
char *identity_files[SSH_MAX_IDENTITY_FILES];
|
|
Key *identity_keys[SSH_MAX_IDENTITY_FILES];
|
|
#ifdef ENABLE_PKCS11
|
|
Key **keys;
|
|
int nkeys;
|
|
#endif /* PKCS11 */
|
|
|
|
n_ids = 0;
|
|
bzero(identity_files, sizeof(identity_files));
|
|
bzero(identity_keys, sizeof(identity_keys));
|
|
|
|
#ifdef ENABLE_PKCS11
|
|
if (options.pkcs11_provider != NULL &&
|
|
options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
|
|
(pkcs11_init(!options.batch_mode) == 0) &&
|
|
(nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL,
|
|
&keys)) > 0) {
|
|
for (i = 0; i < nkeys; i++) {
|
|
if (n_ids >= SSH_MAX_IDENTITY_FILES) {
|
|
key_free(keys[i]);
|
|
continue;
|
|
}
|
|
identity_keys[n_ids] = keys[i];
|
|
identity_files[n_ids] =
|
|
xstrdup(options.pkcs11_provider); /* XXX */
|
|
n_ids++;
|
|
}
|
|
xfree(keys);
|
|
}
|
|
#endif /* ENABLE_PKCS11 */
|
|
if ((pw = getpwuid(original_real_uid)) == NULL)
|
|
fatal("load_public_identity_files: getpwuid failed");
|
|
pwname = xstrdup(pw->pw_name);
|
|
pwdir = xstrdup(pw->pw_dir);
|
|
if (gethostname(thishost, sizeof(thishost)) == -1)
|
|
fatal("load_public_identity_files: gethostname: %s",
|
|
strerror(errno));
|
|
for (i = 0; i < options.num_identity_files; i++) {
|
|
if (n_ids >= SSH_MAX_IDENTITY_FILES) {
|
|
xfree(options.identity_files[i]);
|
|
continue;
|
|
}
|
|
cp = tilde_expand_filename(options.identity_files[i],
|
|
original_real_uid);
|
|
filename = percent_expand(cp, "d", pwdir,
|
|
"u", pwname, "l", thishost, "h", host,
|
|
"r", options.user, (char *)NULL);
|
|
xfree(cp);
|
|
public = key_load_public(filename, NULL);
|
|
debug("identity file %s type %d", filename,
|
|
public ? public->type : -1);
|
|
xfree(options.identity_files[i]);
|
|
identity_files[n_ids] = filename;
|
|
identity_keys[n_ids] = public;
|
|
|
|
if (++n_ids >= SSH_MAX_IDENTITY_FILES)
|
|
continue;
|
|
|
|
/* Try to add the certificate variant too */
|
|
xasprintf(&cp, "%s-cert", filename);
|
|
public = key_load_public(cp, NULL);
|
|
debug("identity file %s type %d", cp,
|
|
public ? public->type : -1);
|
|
if (public == NULL) {
|
|
xfree(cp);
|
|
continue;
|
|
}
|
|
if (!key_is_cert(public)) {
|
|
debug("%s: key %s type %s is not a certificate",
|
|
__func__, cp, key_type(public));
|
|
key_free(public);
|
|
xfree(cp);
|
|
continue;
|
|
}
|
|
identity_keys[n_ids] = public;
|
|
/* point to the original path, most likely the private key */
|
|
identity_files[n_ids] = xstrdup(filename);
|
|
n_ids++;
|
|
}
|
|
options.num_identity_files = n_ids;
|
|
memcpy(options.identity_files, identity_files, sizeof(identity_files));
|
|
memcpy(options.identity_keys, identity_keys, sizeof(identity_keys));
|
|
|
|
bzero(pwname, strlen(pwname));
|
|
xfree(pwname);
|
|
bzero(pwdir, strlen(pwdir));
|
|
xfree(pwdir);
|
|
}
|
|
|
|
static void
|
|
main_sigchld_handler(int sig)
|
|
{
|
|
int save_errno = errno;
|
|
pid_t pid;
|
|
int status;
|
|
|
|
while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
|
|
(pid < 0 && errno == EINTR))
|
|
;
|
|
|
|
signal(sig, main_sigchld_handler);
|
|
errno = save_errno;
|
|
}
|
|
|