1221 lines
35 KiB
C
1221 lines
35 KiB
C
/*
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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 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("$OpenBSD: ssh.c,v 1.186 2002/09/19 01:58:18 djm Exp $");
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RCSID("$FreeBSD$");
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#include <openssl/evp.h>
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#include <openssl/err.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 "compat.h"
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#include "cipher.h"
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#include "xmalloc.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 "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 "tildexpand.h"
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#include "dispatch.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 "sshtty.h"
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#ifdef SMARTCARD
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#include "scard.h"
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#endif
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#ifdef HAVE___PROGNAME
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extern char *__progname;
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#else
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char *__progname;
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#endif
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/* Flag indicating whether IPv4 or IPv6. This can be set on the command line.
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Default value is AF_UNSPEC means both IPv4 and IPv6. */
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#ifdef IPV4_DEFAULT
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int IPv4or6 = AF_INET;
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#else
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int IPv4or6 = AF_UNSPEC;
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#endif
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/* Flag indicating whether debug mode is on. This can 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 allocated */
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int tty_flag = 0;
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int no_tty_flag = 0;
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int force_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 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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/*
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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 client_global_request_id = 0;
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/* pid of proxycommand child process */
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pid_t proxy_command_pid = 0;
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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, "Usage: %s [options] host [command]\n", __progname);
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fprintf(stderr, "Options:\n");
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fprintf(stderr, " -l user Log in using this user name.\n");
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fprintf(stderr, " -n Redirect input from " _PATH_DEVNULL ".\n");
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fprintf(stderr, " -F config Config file (default: ~/%s).\n",
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_PATH_SSH_USER_CONFFILE);
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fprintf(stderr, " -A Enable authentication agent forwarding.\n");
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fprintf(stderr, " -a Disable authentication agent forwarding (default).\n");
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#ifdef AFS
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fprintf(stderr, " -k Disable Kerberos ticket and AFS token forwarding.\n");
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#endif /* AFS */
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fprintf(stderr, " -X Enable X11 connection forwarding.\n");
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fprintf(stderr, " -x Disable X11 connection forwarding (default).\n");
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fprintf(stderr, " -i file Identity for public key authentication "
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"(default: ~/.ssh/identity)\n");
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#ifdef SMARTCARD
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fprintf(stderr, " -I reader Set smartcard reader.\n");
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#endif
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fprintf(stderr, " -t Tty; allocate a tty even if command is given.\n");
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fprintf(stderr, " -T Do not allocate a tty.\n");
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fprintf(stderr, " -v Verbose; display verbose debugging messages.\n");
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fprintf(stderr, " Multiple -v increases verbosity.\n");
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fprintf(stderr, " -V Display version number only.\n");
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fprintf(stderr, " -q Quiet; don't display any warning messages.\n");
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fprintf(stderr, " -f Fork into background after authentication.\n");
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fprintf(stderr, " -e char Set escape character; ``none'' = disable (default: ~).\n");
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fprintf(stderr, " -c cipher Select encryption algorithm\n");
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fprintf(stderr, " -m macs Specify MAC algorithms for protocol version 2.\n");
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fprintf(stderr, " -p port Connect to this port. Server must be on the same port.\n");
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fprintf(stderr, " -L listen-port:host:port Forward local port to remote address\n");
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fprintf(stderr, " -R listen-port:host:port Forward remote port to local address\n");
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fprintf(stderr, " These cause %s to listen for connections on a port, and\n", __progname);
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fprintf(stderr, " forward them to the other side by connecting to host:port.\n");
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fprintf(stderr, " -D port Enable dynamic application-level port forwarding.\n");
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fprintf(stderr, " -C Enable compression.\n");
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fprintf(stderr, " -N Do not execute a shell or command.\n");
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fprintf(stderr, " -g Allow remote hosts to connect to forwarded ports.\n");
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fprintf(stderr, " -1 Force protocol version 1.\n");
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fprintf(stderr, " -2 Force protocol version 2.\n");
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fprintf(stderr, " -4 Use IPv4 only.\n");
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fprintf(stderr, " -6 Use IPv6 only.\n");
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fprintf(stderr, " -o 'option' Process the option as if it was read from a configuration file.\n");
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fprintf(stderr, " -s Invoke command (mandatory) as SSH2 subsystem.\n");
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fprintf(stderr, " -b addr Local IP address.\n");
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exit(1);
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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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/*
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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, opt, exit_status;
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u_short fwd_port, fwd_host_port;
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char sfwd_port[6], sfwd_host_port[6];
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char *p, *cp, buf[256];
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struct stat st;
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struct passwd *pw;
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int dummy;
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extern int optind, optreset;
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extern char *optarg;
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__progname = get_progname(av[0]);
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init_rng();
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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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log("unknown user %d", original_real_uid);
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exit(1);
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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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/* Initialize option structure to indicate that no values have been set. */
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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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again:
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while ((opt = getopt(ac, av,
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"1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:NPR:TVX")) != -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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IPv4or6 = AF_INET;
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break;
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case '6':
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IPv4or6 = 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 'g':
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options.gateway_ports = 1;
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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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#ifdef AFS
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case 'k':
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options.kerberos_tgt_passing = 0;
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options.afs_token_passing = 0;
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break;
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#endif
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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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"does not exist.\n", optarg);
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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 SMARTCARD
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options.smartcard_device = xstrdup(optarg);
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#else
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fprintf(stderr, "no support for smartcards.\n");
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#endif
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break;
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case 't':
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if (tty_flag)
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force_tty_flag = 1;
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tty_flag = 1;
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break;
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case 'v':
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if (0 == debug_flag) {
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debug_flag = 1;
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options.log_level = SYSLOG_LEVEL_DEBUG1;
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} else if (options.log_level < SYSLOG_LEVEL_DEBUG3) {
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options.log_level++;
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break;
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} else
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fatal("Too high debugging level.");
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/* fallthrough */
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case 'V':
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fprintf(stderr,
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"%s, SSH protocols %d.%d/%d.%d, OpenSSL 0x%8.8lx\n",
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SSH_VERSION,
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PROTOCOL_MAJOR_1, PROTOCOL_MINOR_1,
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PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2,
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SSLeay());
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if (opt == 'V')
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exit(0);
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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;
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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(1);
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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_ILLEGAL;
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} else {
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/* SSH1 only */
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options.cipher = cipher_number(optarg);
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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(1);
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}
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if (options.cipher == SSH_CIPHER_3DES)
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options.ciphers = "3des-cbc";
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else if (options.cipher == SSH_CIPHER_BLOWFISH)
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options.ciphers = "blowfish-cbc";
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else
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options.ciphers = (char *)-1;
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}
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break;
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case 'm':
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if (mac_valid(optarg))
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options.macs = xstrdup(optarg);
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else {
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fprintf(stderr, "Unknown mac type '%s'\n",
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optarg);
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exit(1);
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}
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break;
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case 'p':
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options.port = a2port(optarg);
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if (options.port == 0) {
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fprintf(stderr, "Bad port '%s'\n", optarg);
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exit(1);
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}
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break;
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case 'l':
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options.user = optarg;
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break;
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case 'L':
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case 'R':
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if (sscanf(optarg, "%5[0-9]:%255[^:]:%5[0-9]",
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sfwd_port, buf, sfwd_host_port) != 3 &&
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sscanf(optarg, "%5[0-9]/%255[^/]/%5[0-9]",
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sfwd_port, buf, sfwd_host_port) != 3) {
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fprintf(stderr,
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"Bad forwarding specification '%s'\n",
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optarg);
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usage();
|
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/* NOTREACHED */
|
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}
|
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if ((fwd_port = a2port(sfwd_port)) == 0 ||
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(fwd_host_port = a2port(sfwd_host_port)) == 0) {
|
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fprintf(stderr,
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"Bad forwarding port(s) '%s'\n", optarg);
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exit(1);
|
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}
|
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if (opt == 'L')
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add_local_forward(&options, fwd_port, buf,
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fwd_host_port);
|
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else if (opt == 'R')
|
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add_remote_forward(&options, fwd_port, buf,
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fwd_host_port);
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break;
|
|
|
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case 'D':
|
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fwd_port = a2port(optarg);
|
|
if (fwd_port == 0) {
|
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fprintf(stderr, "Bad dynamic port '%s'\n",
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optarg);
|
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exit(1);
|
|
}
|
|
add_local_forward(&options, fwd_port, "socks4", 0);
|
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break;
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|
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case 'C':
|
|
options.compression = 1;
|
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break;
|
|
case 'N':
|
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no_shell_flag = 1;
|
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no_tty_flag = 1;
|
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break;
|
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case 'T':
|
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no_tty_flag = 1;
|
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break;
|
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case 'o':
|
|
dummy = 1;
|
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if (process_config_line(&options, host ? host : "",
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|
optarg, "command-line", 0, &dummy) != 0)
|
|
exit(1);
|
|
break;
|
|
case 's':
|
|
subsystem_flag = 1;
|
|
break;
|
|
case 'b':
|
|
options.bind_address = optarg;
|
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break;
|
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case 'F':
|
|
config = optarg;
|
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break;
|
|
default:
|
|
usage();
|
|
}
|
|
}
|
|
|
|
ac -= optind;
|
|
av += optind;
|
|
|
|
if (ac > 0 && !host && **av != '-') {
|
|
if (strchr(*av, '@')) {
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|
p = xstrdup(*av);
|
|
cp = strchr(p, '@');
|
|
if (cp == NULL || cp == p)
|
|
usage();
|
|
options.user = p;
|
|
*cp = '\0';
|
|
host = ++cp;
|
|
} else
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host = *av;
|
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ac--, av++;
|
|
if (ac > 0) {
|
|
optind = 0;
|
|
optreset = 1;
|
|
goto again;
|
|
}
|
|
}
|
|
|
|
/* Check that we got a host name. */
|
|
if (!host)
|
|
usage();
|
|
|
|
SSLeay_add_all_algorithms();
|
|
ERR_load_crypto_strings();
|
|
channel_set_af(IPv4or6);
|
|
|
|
/* Initialize the command to execute on remote host. */
|
|
buffer_init(&command);
|
|
|
|
/*
|
|
* 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 = 1;
|
|
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 = 1;
|
|
|
|
/* Force no tty */
|
|
if (no_tty_flag)
|
|
tty_flag = 0;
|
|
/* Do not allocate a tty if stdin is not a tty. */
|
|
if (!isatty(fileno(stdin)) && !force_tty_flag) {
|
|
if (tty_flag)
|
|
log("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(av[0], options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
|
|
SYSLOG_FACILITY_USER, 1);
|
|
|
|
/*
|
|
* 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))
|
|
fatal("Can't open user config file %.100s: "
|
|
"%.100s", config, strerror(errno));
|
|
} else {
|
|
snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir,
|
|
_PATH_SSH_USER_CONFFILE);
|
|
(void)read_config_file(buf, host, &options);
|
|
|
|
/* Read systemwide configuration file after use config. */
|
|
(void)read_config_file(_PATH_HOST_CONFIG_FILE, host, &options);
|
|
}
|
|
|
|
/* Fill configuration defaults. */
|
|
fill_default_options(&options);
|
|
|
|
/* reinit */
|
|
log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 1);
|
|
|
|
seed_rng();
|
|
|
|
if (options.user == NULL)
|
|
options.user = xstrdup(pw->pw_name);
|
|
|
|
if (options.hostname != NULL)
|
|
host = options.hostname;
|
|
|
|
/* 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 = IPv4or6;
|
|
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);
|
|
}
|
|
}
|
|
|
|
/* Disable rhosts authentication if not running as root. */
|
|
#ifdef HAVE_CYGWIN
|
|
/* Ignore uid if running under Windows */
|
|
if (!options.use_privileged_port) {
|
|
#else
|
|
if (original_effective_uid != 0 || !options.use_privileged_port) {
|
|
#endif
|
|
debug("Rhosts Authentication disabled, "
|
|
"originating port will not be trusted.");
|
|
options.rhosts_authentication = 0;
|
|
}
|
|
/* Open a connection to the remote host. */
|
|
|
|
if (ssh_connect(host, &hostaddr, options.port, IPv4or6,
|
|
options.connection_attempts,
|
|
#ifdef HAVE_CYGWIN
|
|
options.use_privileged_port,
|
|
#else
|
|
original_effective_uid == 0 && options.use_privileged_port,
|
|
#endif
|
|
options.proxy_command) != 0)
|
|
exit(1);
|
|
|
|
/*
|
|
* 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 = 3;
|
|
sensitive_data.keys = xmalloc(sensitive_data.nkeys *
|
|
sizeof(Key));
|
|
|
|
PRIV_START;
|
|
sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
|
|
_PATH_HOST_KEY_FILE, "", NULL);
|
|
sensitive_data.keys[1] = key_load_private_type(KEY_DSA,
|
|
_PATH_HOST_DSA_KEY_FILE, "", NULL);
|
|
sensitive_data.keys[2] = key_load_private_type(KEY_RSA,
|
|
_PATH_HOST_RSA_KEY_FILE, "", NULL);
|
|
PRIV_END;
|
|
|
|
if (options.hostbased_authentication == 1 &&
|
|
sensitive_data.keys[0] == NULL &&
|
|
sensitive_data.keys[1] == NULL &&
|
|
sensitive_data.keys[2] == NULL) {
|
|
sensitive_data.keys[1] = key_load_public(
|
|
_PATH_HOST_DSA_KEY_FILE, NULL);
|
|
sensitive_data.keys[2] = 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.
|
|
*/
|
|
seteuid(original_real_uid);
|
|
setuid(original_real_uid);
|
|
|
|
/*
|
|
* Now that we are back to our own permissions, create ~/.ssh
|
|
* directory if it doesn\'t already exist.
|
|
*/
|
|
snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir, strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
|
|
if (stat(buf, &st) < 0)
|
|
if (mkdir(buf, 0700) < 0)
|
|
error("Could not create directory '%.200s'.", buf);
|
|
|
|
/* load options.identity_files */
|
|
load_public_identity_files();
|
|
|
|
/* Expand ~ in known host file names. */
|
|
/* XXX mem-leaks: */
|
|
options.system_hostfile =
|
|
tilde_expand_filename(options.system_hostfile, original_real_uid);
|
|
options.user_hostfile =
|
|
tilde_expand_filename(options.user_hostfile, original_real_uid);
|
|
options.system_hostfile2 =
|
|
tilde_expand_filename(options.system_hostfile2, original_real_uid);
|
|
options.user_hostfile2 =
|
|
tilde_expand_filename(options.user_hostfile2, original_real_uid);
|
|
|
|
signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
|
|
|
|
/* Log into the remote system. This never returns if the login fails. */
|
|
ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, pw);
|
|
|
|
/* 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();
|
|
|
|
/*
|
|
* Send SIGHUP to proxy command if used. We don't wait() in
|
|
* case it hangs and instead rely on init to reap the child
|
|
*/
|
|
if (proxy_command_pid > 1)
|
|
kill(proxy_command_pid, SIGHUP);
|
|
|
|
return exit_status;
|
|
}
|
|
|
|
static void
|
|
x11_get_proto(char **_proto, char **_data)
|
|
{
|
|
char line[512];
|
|
static char proto[512], data[512];
|
|
FILE *f;
|
|
int got_data = 0, i;
|
|
char *display;
|
|
struct stat st;
|
|
|
|
*_proto = proto;
|
|
*_data = data;
|
|
proto[0] = data[0] = '\0';
|
|
if (!options.xauth_location ||
|
|
(stat(options.xauth_location, &st) == -1)) {
|
|
debug("No xauth program.");
|
|
} else {
|
|
if ((display = getenv("DISPLAY")) == NULL) {
|
|
debug("x11_get_proto: DISPLAY not set");
|
|
return;
|
|
}
|
|
/* Try to get Xauthority information for the display. */
|
|
if (strncmp(display, "localhost:", 10) == 0)
|
|
/*
|
|
* Handle FamilyLocal case where $DISPLAY does
|
|
* not match an authorization entry. For this we
|
|
* just try "xauth list unix:displaynum.screennum".
|
|
* XXX: "localhost" match to determine FamilyLocal
|
|
* is not perfect.
|
|
*/
|
|
snprintf(line, sizeof line, "%s list unix:%s 2>"
|
|
_PATH_DEVNULL, options.xauth_location, display+10);
|
|
else
|
|
snprintf(line, sizeof line, "%s list %.200s 2>"
|
|
_PATH_DEVNULL, options.xauth_location, display);
|
|
debug2("x11_get_proto: %s", line);
|
|
f = popen(line, "r");
|
|
if (f && fgets(line, sizeof(line), f) &&
|
|
sscanf(line, "%*s %511s %511s", proto, data) == 2)
|
|
got_data = 1;
|
|
if (f)
|
|
pclose(f);
|
|
}
|
|
/*
|
|
* If we didn't get authentication data, just make up some
|
|
* data. The forwarding code will check the validity of the
|
|
* response anyway, and substitute this data. The X11
|
|
* server, however, will ignore this fake data and use
|
|
* whatever authentication mechanisms it was using otherwise
|
|
* for the local connection.
|
|
*/
|
|
if (!got_data) {
|
|
u_int32_t rand = 0;
|
|
|
|
log("Warning: No xauth data; using fake authentication data for X11 forwarding.");
|
|
strlcpy(proto, "MIT-MAGIC-COOKIE-1", sizeof proto);
|
|
for (i = 0; i < 16; i++) {
|
|
if (i % 4 == 0)
|
|
rand = arc4random();
|
|
snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", rand & 0xff);
|
|
rand >>= 8;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
ssh_init_forwarding(void)
|
|
{
|
|
int success = 0;
|
|
int i;
|
|
|
|
/* Initiate local TCP/IP port forwardings. */
|
|
for (i = 0; i < options.num_local_forwards; i++) {
|
|
debug("Connections to local port %d forwarded to remote address %.200s:%d",
|
|
options.local_forwards[i].port,
|
|
options.local_forwards[i].host,
|
|
options.local_forwards[i].host_port);
|
|
success += channel_setup_local_fwd_listener(
|
|
options.local_forwards[i].port,
|
|
options.local_forwards[i].host,
|
|
options.local_forwards[i].host_port,
|
|
options.gateway_ports);
|
|
}
|
|
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("Connections to remote port %d forwarded to local address %.200s:%d",
|
|
options.remote_forwards[i].port,
|
|
options.remote_forwards[i].host,
|
|
options.remote_forwards[i].host_port);
|
|
channel_request_remote_forwarding(
|
|
options.remote_forwards[i].port,
|
|
options.remote_forwards[i].host,
|
|
options.remote_forwards[i].host_port);
|
|
}
|
|
}
|
|
|
|
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;
|
|
|
|
/* 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)
|
|
log("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(ws.ws_row);
|
|
packet_put_int(ws.ws_col);
|
|
packet_put_int(ws.ws_xpixel);
|
|
packet_put_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)
|
|
log("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. */
|
|
if (options.forward_x11 && getenv("DISPLAY") != NULL) {
|
|
char *proto, *data;
|
|
/* Get reasonable local authentication information. */
|
|
x11_get_proto(&proto, &data);
|
|
/* Request forwarding with authentication spoofing. */
|
|
debug("Requesting X11 forwarding with authentication spoofing.");
|
|
x11_request_forwarding_with_spoofing(0, proto, data);
|
|
|
|
/* Read response from the server. */
|
|
type = packet_read();
|
|
if (type == SSH_SMSG_SUCCESS) {
|
|
interactive = 1;
|
|
} else if (type == SSH_SMSG_FAILURE) {
|
|
log("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);
|
|
|
|
/* 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)
|
|
log("Warning: Remote host denied authentication agent forwarding.");
|
|
}
|
|
|
|
/* Initiate port forwardings. */
|
|
ssh_init_forwarding();
|
|
|
|
/* If requested, let ssh continue in the background. */
|
|
if (fork_after_authentication_flag)
|
|
if (daemon(1, 1) < 0)
|
|
fatal("daemon() failed: %.200s", strerror(errno));
|
|
|
|
/*
|
|
* 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);
|
|
}
|
|
|
|
static void
|
|
client_subsystem_reply(int type, u_int32_t seq, void *ctxt)
|
|
{
|
|
int id, len;
|
|
|
|
id = packet_get_int();
|
|
len = buffer_len(&command);
|
|
if (len > 900)
|
|
len = 900;
|
|
packet_check_eom();
|
|
if (type == SSH2_MSG_CHANNEL_FAILURE)
|
|
fatal("Request for subsystem '%.*s' failed on channel %d",
|
|
len, (u_char *)buffer_ptr(&command), id);
|
|
}
|
|
|
|
void
|
|
client_global_request_reply(int type, u_int32_t seq, void *ctxt)
|
|
{
|
|
int i;
|
|
|
|
i = client_global_request_id++;
|
|
if (i >= options.num_remote_forwards) {
|
|
debug("client_global_request_reply: too many replies %d > %d",
|
|
i, options.num_remote_forwards);
|
|
return;
|
|
}
|
|
debug("remote forward %s for: listen %d, connect %s:%d",
|
|
type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
|
|
options.remote_forwards[i].port,
|
|
options.remote_forwards[i].host,
|
|
options.remote_forwards[i].host_port);
|
|
if (type == SSH2_MSG_REQUEST_FAILURE)
|
|
log("Warning: remote port forwarding failed for listen port %d",
|
|
options.remote_forwards[i].port);
|
|
}
|
|
|
|
/* request pty/x11/agent/tcpfwd/shell for channel */
|
|
static void
|
|
ssh_session2_setup(int id, void *arg)
|
|
{
|
|
int len;
|
|
int interactive = 0;
|
|
struct termios tio;
|
|
|
|
debug("ssh_session2_setup: id %d", id);
|
|
|
|
if (tty_flag) {
|
|
struct winsize ws;
|
|
char *cp;
|
|
cp = getenv("TERM");
|
|
if (!cp)
|
|
cp = "";
|
|
/* Store window size in the packet. */
|
|
if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
|
|
memset(&ws, 0, sizeof(ws));
|
|
|
|
channel_request_start(id, "pty-req", 0);
|
|
packet_put_cstring(cp);
|
|
packet_put_int(ws.ws_col);
|
|
packet_put_int(ws.ws_row);
|
|
packet_put_int(ws.ws_xpixel);
|
|
packet_put_int(ws.ws_ypixel);
|
|
tio = get_saved_tio();
|
|
tty_make_modes(/*ignored*/ 0, &tio);
|
|
packet_send();
|
|
interactive = 1;
|
|
/* XXX wait for reply */
|
|
}
|
|
if (options.forward_x11 &&
|
|
getenv("DISPLAY") != NULL) {
|
|
char *proto, *data;
|
|
/* Get reasonable local authentication information. */
|
|
x11_get_proto(&proto, &data);
|
|
/* Request forwarding with authentication spoofing. */
|
|
debug("Requesting X11 forwarding with authentication spoofing.");
|
|
x11_request_forwarding_with_spoofing(id, proto, data);
|
|
interactive = 1;
|
|
/* XXX wait for reply */
|
|
}
|
|
|
|
check_agent_present();
|
|
if (options.forward_agent) {
|
|
debug("Requesting authentication agent forwarding.");
|
|
channel_request_start(id, "auth-agent-req@openssh.com", 0);
|
|
packet_send();
|
|
}
|
|
|
|
len = buffer_len(&command);
|
|
if (len > 0) {
|
|
if (len > 900)
|
|
len = 900;
|
|
if (subsystem_flag) {
|
|
debug("Sending subsystem: %.*s", len, (u_char *)buffer_ptr(&command));
|
|
channel_request_start(id, "subsystem", /*want reply*/ 1);
|
|
/* register callback for reply */
|
|
/* XXX we assume that client_loop has already been called */
|
|
dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &client_subsystem_reply);
|
|
dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &client_subsystem_reply);
|
|
} else {
|
|
debug("Sending command: %.*s", len, (u_char *)buffer_ptr(&command));
|
|
channel_request_start(id, "exec", 0);
|
|
}
|
|
packet_put_string(buffer_ptr(&command), buffer_len(&command));
|
|
packet_send();
|
|
} else {
|
|
channel_request_start(id, "shell", 0);
|
|
packet_send();
|
|
}
|
|
|
|
packet_set_interactive(interactive);
|
|
}
|
|
|
|
/* 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);
|
|
|
|
window = CHAN_SES_WINDOW_DEFAULT;
|
|
packetmax = CHAN_SES_PACKET_DEFAULT;
|
|
if (tty_flag) {
|
|
window >>= 1;
|
|
packetmax >>= 1;
|
|
}
|
|
c = channel_new(
|
|
"session", SSH_CHANNEL_OPENING, in, out, err,
|
|
window, packetmax, CHAN_EXTENDED_WRITE,
|
|
xstrdup("client-session"), /*nonblock*/0);
|
|
|
|
debug3("ssh_session2_open: channel_new: %d", c->self);
|
|
|
|
channel_send_open(c->self);
|
|
if (!no_shell_flag)
|
|
channel_register_confirm(c->self, ssh_session2_setup);
|
|
|
|
return c->self;
|
|
}
|
|
|
|
static int
|
|
ssh_session2(void)
|
|
{
|
|
int id = -1;
|
|
|
|
/* XXX should be pre-session */
|
|
ssh_init_forwarding();
|
|
|
|
if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
|
|
id = ssh_session2_open();
|
|
|
|
/* If requested, let ssh continue in the background. */
|
|
if (fork_after_authentication_flag)
|
|
if (daemon(1, 1) < 0)
|
|
fatal("daemon() failed: %.200s", strerror(errno));
|
|
|
|
return client_loop(tty_flag, tty_flag ?
|
|
options.escape_char : SSH_ESCAPECHAR_NONE, id);
|
|
}
|
|
|
|
static void
|
|
load_public_identity_files(void)
|
|
{
|
|
char *filename;
|
|
int i = 0;
|
|
Key *public;
|
|
#ifdef SMARTCARD
|
|
Key **keys;
|
|
|
|
if (options.smartcard_device != NULL &&
|
|
options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
|
|
(keys = sc_get_keys(options.smartcard_device, NULL)) != NULL ) {
|
|
int count = 0;
|
|
for (i = 0; keys[i] != NULL; i++) {
|
|
count++;
|
|
memmove(&options.identity_files[1], &options.identity_files[0],
|
|
sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1));
|
|
memmove(&options.identity_keys[1], &options.identity_keys[0],
|
|
sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1));
|
|
options.num_identity_files++;
|
|
options.identity_keys[0] = keys[i];
|
|
options.identity_files[0] = xstrdup("smartcard key");;
|
|
}
|
|
if (options.num_identity_files > SSH_MAX_IDENTITY_FILES)
|
|
options.num_identity_files = SSH_MAX_IDENTITY_FILES;
|
|
i = count;
|
|
xfree(keys);
|
|
}
|
|
#endif /* SMARTCARD */
|
|
for (; i < options.num_identity_files; i++) {
|
|
filename = tilde_expand_filename(options.identity_files[i],
|
|
original_real_uid);
|
|
public = key_load_public(filename, NULL);
|
|
debug("identity file %s type %d", filename,
|
|
public ? public->type : -1);
|
|
xfree(options.identity_files[i]);
|
|
options.identity_files[i] = filename;
|
|
options.identity_keys[i] = public;
|
|
}
|
|
}
|