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ssh.c
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/* $OpenBSD: ssh.c,v 1.608 2025/03/02 11:03:13 djm Exp $ */
/*
* Author: Tatu Ylonen <[email protected]>
* Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
* All rights reserved
* Ssh client program. This program can be used to log into a remote machine.
* The software supports strong authentication, encryption, and forwarding
* of X11, TCP/IP, and authentication connections.
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*
* Copyright (c) 1999 Niels Provos. All rights reserved.
* Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved.
*
* Modified to work with SSLeay by Niels Provos <[email protected]>
* in Canada (German citizen).
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "includes.h"
#include <sys/types.h>
#ifdef HAVE_SYS_STAT_H
# include <sys/stat.h>
#endif
#include <sys/resource.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <sys/utsname.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#ifdef HAVE_PATHS_H
#include <paths.h>
#endif
#include <pwd.h>
#include <signal.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>
#include <limits.h>
#include <locale.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#ifdef WITH_OPENSSL
#include <openssl/evp.h>
#include <openssl/err.h>
#endif
#include "openbsd-compat/openssl-compat.h"
#include "openbsd-compat/sys-queue.h"
#include "xmalloc.h"
#include "ssh.h"
#include "ssh2.h"
#include "canohost.h"
#include "compat.h"
#include "cipher.h"
#include "packet.h"
#include "sshbuf.h"
#include "channels.h"
#include "sshkey.h"
#include "authfd.h"
#include "authfile.h"
#include "pathnames.h"
#include "dispatch.h"
#include "clientloop.h"
#include "log.h"
#include "misc.h"
#include "readconf.h"
#include "sshconnect.h"
#include "kex.h"
#include "mac.h"
#include "sshpty.h"
#include "match.h"
#include "msg.h"
#include "version.h"
#include "ssherr.h"
#include "myproposal.h"
#include "utf8.h"
#ifdef ENABLE_PKCS11
#include "ssh-pkcs11.h"
#endif
extern char *__progname;
/* Saves a copy of argv for setproctitle emulation */
#ifndef HAVE_SETPROCTITLE
static char **saved_av;
#endif
/* Flag indicating whether debug mode is on. May be set on the command line. */
int debug_flag = 0;
/* Flag indicating whether a tty should be requested */
int tty_flag = 0;
/*
* Flag indicating that the current process should be backgrounded and
* a new mux-client launched in the foreground for ControlPersist.
*/
static int need_controlpersist_detach = 0;
/* Copies of flags for ControlPersist foreground mux-client */
static int ostdin_null_flag, osession_type, otty_flag, orequest_tty;
static int ofork_after_authentication;
/*
* General data structure for command line options and options configurable
* in configuration files. See readconf.h.
*/
Options options;
/* optional user configfile */
char *config = NULL;
/*
* Name of the host we are connecting to. This is the name given on the
* command line, or the Hostname specified for the user-supplied name in a
* configuration file.
*/
char *host;
/*
* A config can specify a path to forward, overriding SSH_AUTH_SOCK. If this is
* not NULL, forward the socket at this path instead.
*/
char *forward_agent_sock_path = NULL;
/* socket address the host resolves to */
struct sockaddr_storage hostaddr;
/* Private host keys. */
Sensitive sensitive_data;
/* command to be executed */
struct sshbuf *command;
/* # of replies received for global requests */
static int forward_confirms_pending = -1;
/* mux.c */
extern int muxserver_sock;
extern u_int muxclient_command;
/* Prints a help message to the user. This function never returns. */
static void
usage(void)
{
fprintf(stderr,
"usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface] [-b bind_address]\n"
" [-c cipher_spec] [-D [bind_address:]port] [-E log_file]\n"
" [-e escape_char] [-F configfile] [-I pkcs11] [-i identity_file]\n"
" [-J destination] [-L address] [-l login_name] [-m mac_spec]\n"
" [-O ctl_cmd] [-o option] [-P tag] [-p port] [-R address]\n"
" [-S ctl_path] [-W host:port] [-w local_tun[:remote_tun]]\n"
" destination [command [argument ...]]\n"
" ssh [-Q query_option]\n"
);
exit(255);
}
static int ssh_session2(struct ssh *, const struct ssh_conn_info *);
static void load_public_identity_files(const struct ssh_conn_info *);
static void main_sigchld_handler(int);
/* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */
static void
tilde_expand_paths(char **paths, u_int num_paths)
{
u_int i;
char *cp;
for (i = 0; i < num_paths; i++) {
cp = tilde_expand_filename(paths[i], getuid());
free(paths[i]);
paths[i] = cp;
}
}
/*
* Expands the set of percent_expand options used by the majority of keywords
* in the client that support percent expansion.
* Caller must free returned string.
*/
static char *
default_client_percent_expand(const char *str,
const struct ssh_conn_info *cinfo)
{
return percent_expand(str,
DEFAULT_CLIENT_PERCENT_EXPAND_ARGS(cinfo),
(char *)NULL);
}
/*
* Expands the set of percent_expand options used by the majority of keywords
* AND perform environment variable substitution.
* Caller must free returned string.
*/
static char *
default_client_percent_dollar_expand(const char *str,
const struct ssh_conn_info *cinfo)
{
char *ret;
ret = percent_dollar_expand(str,
DEFAULT_CLIENT_PERCENT_EXPAND_ARGS(cinfo),
(char *)NULL);
if (ret == NULL)
fatal("invalid environment variable expansion");
return ret;
}
/*
* Attempt to resolve a host name / port to a set of addresses and
* optionally return any CNAMEs encountered along the way.
* Returns NULL on failure.
* NB. this function must operate with a options having undefined members.
*/
static struct addrinfo *
resolve_host(const char *name, int port, int logerr, char *cname, size_t clen)
{
char strport[NI_MAXSERV];
const char *errstr = NULL;
struct addrinfo hints, *res;
int gaierr;
LogLevel loglevel = SYSLOG_LEVEL_DEBUG1;
if (port <= 0)
port = default_ssh_port();
if (cname != NULL)
*cname = '\0';
debug3_f("lookup %s:%d", name, port);
snprintf(strport, sizeof strport, "%d", port);
memset(&hints, 0, sizeof(hints));
hints.ai_family = options.address_family == -1 ?
AF_UNSPEC : options.address_family;
hints.ai_socktype = SOCK_STREAM;
if (cname != NULL)
hints.ai_flags = AI_CANONNAME;
if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) {
if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA))
loglevel = SYSLOG_LEVEL_ERROR;
do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s",
__progname, name, ssh_gai_strerror(gaierr));
return NULL;
}
if (cname != NULL && res->ai_canonname != NULL) {
if (!valid_domain(res->ai_canonname, 0, &errstr)) {
error("ignoring bad CNAME \"%s\" for host \"%s\": %s",
res->ai_canonname, name, errstr);
} else if (strlcpy(cname, res->ai_canonname, clen) >= clen) {
error_f("host \"%s\" cname \"%s\" too long (max %lu)",
name, res->ai_canonname, (u_long)clen);
if (clen > 0)
*cname = '\0';
}
}
return res;
}
/* Returns non-zero if name can only be an address and not a hostname */
static int
is_addr_fast(const char *name)
{
return (strchr(name, '%') != NULL || strchr(name, ':') != NULL ||
strspn(name, "0123456789.") == strlen(name));
}
/* Returns non-zero if name represents a valid, single address */
static int
is_addr(const char *name)
{
char strport[NI_MAXSERV];
struct addrinfo hints, *res;
if (is_addr_fast(name))
return 1;
snprintf(strport, sizeof strport, "%u", default_ssh_port());
memset(&hints, 0, sizeof(hints));
hints.ai_family = options.address_family == -1 ?
AF_UNSPEC : options.address_family;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV;
if (getaddrinfo(name, strport, &hints, &res) != 0)
return 0;
if (res == NULL || res->ai_next != NULL) {
freeaddrinfo(res);
return 0;
}
freeaddrinfo(res);
return 1;
}
/*
* Attempt to resolve a numeric host address / port to a single address.
* Returns a canonical address string.
* Returns NULL on failure.
* NB. this function must operate with a options having undefined members.
*/
static struct addrinfo *
resolve_addr(const char *name, int port, char *caddr, size_t clen)
{
char addr[NI_MAXHOST], strport[NI_MAXSERV];
struct addrinfo hints, *res;
int gaierr;
if (port <= 0)
port = default_ssh_port();
snprintf(strport, sizeof strport, "%u", port);
memset(&hints, 0, sizeof(hints));
hints.ai_family = options.address_family == -1 ?
AF_UNSPEC : options.address_family;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV;
if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) {
debug2_f("could not resolve name %.100s as address: %s",
name, ssh_gai_strerror(gaierr));
return NULL;
}
if (res == NULL) {
debug_f("getaddrinfo %.100s returned no addresses", name);
return NULL;
}
if (res->ai_next != NULL) {
debug_f("getaddrinfo %.100s returned multiple addresses", name);
goto fail;
}
if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen,
addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) {
debug_f("Could not format address for name %.100s: %s",
name, ssh_gai_strerror(gaierr));
goto fail;
}
if (strlcpy(caddr, addr, clen) >= clen) {
error_f("host \"%s\" addr \"%s\" too long (max %lu)",
name, addr, (u_long)clen);
if (clen > 0)
*caddr = '\0';
fail:
freeaddrinfo(res);
return NULL;
}
return res;
}
/*
* Check whether the cname is a permitted replacement for the hostname
* and perform the replacement if it is.
* NB. this function must operate with a options having undefined members.
*/
static int
check_follow_cname(int direct, char **namep, const char *cname)
{
int i;
struct allowed_cname *rule;
if (*cname == '\0' || !config_has_permitted_cnames(&options) ||
strcmp(*namep, cname) == 0)
return 0;
if (options.canonicalize_hostname == SSH_CANONICALISE_NO)
return 0;
/*
* Don't attempt to canonicalize names that will be interpreted by
* a proxy or jump host unless the user specifically requests so.
*/
if (!direct &&
options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS)
return 0;
debug3_f("check \"%s\" CNAME \"%s\"", *namep, cname);
for (i = 0; i < options.num_permitted_cnames; i++) {
rule = options.permitted_cnames + i;
if (match_pattern_list(*namep, rule->source_list, 1) != 1 ||
match_pattern_list(cname, rule->target_list, 1) != 1)
continue;
verbose("Canonicalized DNS aliased hostname "
"\"%s\" => \"%s\"", *namep, cname);
free(*namep);
*namep = xstrdup(cname);
return 1;
}
return 0;
}
/*
* Attempt to resolve the supplied hostname after applying the user's
* canonicalization rules. Returns the address list for the host or NULL
* if no name was found after canonicalization.
* NB. this function must operate with a options having undefined members.
*/
static struct addrinfo *
resolve_canonicalize(char **hostp, int port)
{
int i, direct, ndots;
char *cp, *fullhost, newname[NI_MAXHOST];
struct addrinfo *addrs;
/*
* Attempt to canonicalise addresses, regardless of
* whether hostname canonicalisation was requested
*/
if ((addrs = resolve_addr(*hostp, port,
newname, sizeof(newname))) != NULL) {
debug2_f("hostname %.100s is address", *hostp);
if (strcasecmp(*hostp, newname) != 0) {
debug2_f("canonicalised address \"%s\" => \"%s\"",
*hostp, newname);
free(*hostp);
*hostp = xstrdup(newname);
}
return addrs;
}
/*
* If this looks like an address but didn't parse as one, it might
* be an address with an invalid interface scope. Skip further
* attempts at canonicalisation.
*/
if (is_addr_fast(*hostp)) {
debug_f("hostname %.100s is an unrecognised address", *hostp);
return NULL;
}
if (options.canonicalize_hostname == SSH_CANONICALISE_NO)
return NULL;
/*
* Don't attempt to canonicalize names that will be interpreted by
* a proxy unless the user specifically requests so.
*/
direct = option_clear_or_none(options.proxy_command) &&
option_clear_or_none(options.jump_host);
if (!direct &&
options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS)
return NULL;
/* If domain name is anchored, then resolve it now */
if ((*hostp)[strlen(*hostp) - 1] == '.') {
debug3_f("name is fully qualified");
fullhost = xstrdup(*hostp);
if ((addrs = resolve_host(fullhost, port, 0,
newname, sizeof(newname))) != NULL)
goto found;
free(fullhost);
goto notfound;
}
/* Don't apply canonicalization to sufficiently-qualified hostnames */
ndots = 0;
for (cp = *hostp; *cp != '\0'; cp++) {
if (*cp == '.')
ndots++;
}
if (ndots > options.canonicalize_max_dots) {
debug3_f("not canonicalizing hostname \"%s\" (max dots %d)",
*hostp, options.canonicalize_max_dots);
return NULL;
}
/* Attempt each supplied suffix */
for (i = 0; i < options.num_canonical_domains; i++) {
if (strcasecmp(options.canonical_domains[i], "none") == 0)
break;
xasprintf(&fullhost, "%s.%s.", *hostp,
options.canonical_domains[i]);
debug3_f("attempting \"%s\" => \"%s\"", *hostp, fullhost);
if ((addrs = resolve_host(fullhost, port, 0,
newname, sizeof(newname))) == NULL) {
free(fullhost);
continue;
}
found:
/* Remove trailing '.' */
fullhost[strlen(fullhost) - 1] = '\0';
/* Follow CNAME if requested */
if (!check_follow_cname(direct, &fullhost, newname)) {
debug("Canonicalized hostname \"%s\" => \"%s\"",
*hostp, fullhost);
}
free(*hostp);
*hostp = fullhost;
return addrs;
}
notfound:
if (!options.canonicalize_fallback_local)
fatal("%s: Could not resolve host \"%s\"", __progname, *hostp);
debug2_f("host %s not found in any suffix", *hostp);
return NULL;
}
/*
* Check the result of hostkey loading, ignoring some errors and either
* discarding the key or fatal()ing for others.
*/
static void
check_load(int r, struct sshkey **k, const char *path, const char *message)
{
switch (r) {
case 0:
/* Check RSA keys size and discard if undersized */
if (k != NULL && *k != NULL &&
(r = sshkey_check_rsa_length(*k,
options.required_rsa_size)) != 0) {
error_r(r, "load %s \"%s\"", message, path);
free(*k);
*k = NULL;
}
break;
case SSH_ERR_INTERNAL_ERROR:
case SSH_ERR_ALLOC_FAIL:
fatal_r(r, "load %s \"%s\"", message, path);
case SSH_ERR_SYSTEM_ERROR:
/* Ignore missing files */
if (errno == ENOENT)
break;
/* FALLTHROUGH */
default:
error_r(r, "load %s \"%s\"", message, path);
break;
}
}
/*
* Read per-user configuration file. Ignore the system wide config
* file if the user specifies a config file on the command line.
*/
static void
process_config_files(const char *host_name, struct passwd *pw,
int final_pass, int *want_final_pass)
{
char *cmd, buf[PATH_MAX];
int r;
if ((cmd = sshbuf_dup_string(command)) == NULL)
fatal_f("sshbuf_dup_string failed");
if (config != NULL) {
if (strcasecmp(config, "none") != 0 &&
!read_config_file(config, pw, host, host_name, cmd,
&options,
SSHCONF_USERCONF | (final_pass ? SSHCONF_FINAL : 0),
want_final_pass))
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, pw, host, host_name, cmd,
&options, SSHCONF_CHECKPERM | SSHCONF_USERCONF |
(final_pass ? SSHCONF_FINAL : 0), want_final_pass);
/* Read systemwide configuration file after user config. */
(void)read_config_file(_PATH_HOST_CONFIG_FILE, pw,
host, host_name, cmd, &options,
final_pass ? SSHCONF_FINAL : 0, want_final_pass);
}
free(cmd);
}
/* Rewrite the port number in an addrinfo list of addresses */
static void
set_addrinfo_port(struct addrinfo *addrs, int port)
{
struct addrinfo *addr;
for (addr = addrs; addr != NULL; addr = addr->ai_next) {
switch (addr->ai_family) {
case AF_INET:
((struct sockaddr_in *)addr->ai_addr)->
sin_port = htons(port);
break;
case AF_INET6:
((struct sockaddr_in6 *)addr->ai_addr)->
sin6_port = htons(port);
break;
}
}
}
static void
ssh_conn_info_free(struct ssh_conn_info *cinfo)
{
if (cinfo == NULL)
return;
free(cinfo->conn_hash_hex);
free(cinfo->shorthost);
free(cinfo->uidstr);
free(cinfo->keyalias);
free(cinfo->thishost);
free(cinfo->host_arg);
free(cinfo->portstr);
free(cinfo->remhost);
free(cinfo->remuser);
free(cinfo->homedir);
free(cinfo->locuser);
free(cinfo->jmphost);
free(cinfo);
}
static int
valid_hostname(const char *s)
{
size_t i;
if (*s == '-')
return 0;
for (i = 0; s[i] != 0; i++) {
if (strchr("'`\"$\\;&<>|(){},", s[i]) != NULL ||
isspace((u_char)s[i]) || iscntrl((u_char)s[i]))
return 0;
}
return 1;
}
static int
valid_ruser(const char *s)
{
size_t i;
if (*s == '-')
return 0;
for (i = 0; s[i] != 0; i++) {
if (strchr("'`\";&<>|(){}", s[i]) != NULL)
return 0;
/* Disallow '-' after whitespace */
if (isspace((u_char)s[i]) && s[i + 1] == '-')
return 0;
/* Disallow \ in last position */
if (s[i] == '\\' && s[i + 1] == '\0')
return 0;
}
return 1;
}
/*
* Main program for the ssh client.
*/
int
main(int ac, char **av)
{
struct ssh *ssh = NULL;
int i, r, opt, exit_status, use_syslog, direct, timeout_ms;
int was_addr, config_test = 0, opt_terminated = 0, want_final_pass = 0;
char *p, *cp, *line, *argv0, *logfile, *args;
char cname[NI_MAXHOST], thishost[NI_MAXHOST];
struct stat st;
struct passwd *pw;
extern int optind, optreset;
extern char *optarg;
struct Forward fwd;
struct addrinfo *addrs = NULL;
size_t n, len;
u_int j;
struct utsname utsname;
struct ssh_conn_info *cinfo = NULL;
/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
sanitise_stdfd();
/*
* Discard other fds that are hanging around. These can cause problem
* with backgrounded ssh processes started by ControlPersist.
*/
closefrom(STDERR_FILENO + 1);
__progname = ssh_get_progname(av[0]);
#ifndef HAVE_SETPROCTITLE
/* Prepare for later setproctitle emulation */
/* Save argv so it isn't clobbered by setproctitle() emulation */
saved_av = xcalloc(ac + 1, sizeof(*saved_av));
for (i = 0; i < ac; i++)
saved_av[i] = xstrdup(av[i]);
saved_av[i] = NULL;
compat_init_setproctitle(ac, av);
av = saved_av;
#endif
seed_rng();
/* Get user data. */
pw = getpwuid(getuid());
if (!pw) {
logit("No user exists for uid %lu", (u_long)getuid());
exit(255);
}
/* Take a copy of the returned structure. */
pw = pwcopy(pw);
/*
* Set our umask to something reasonable, as some files are created
* with the default umask. This will make them world-readable but
* writable only by the owner, which is ok for all files for which we
* don't set the modes explicitly.
*/
umask(022 | umask(077));
msetlocale();
/*
* Initialize option structure to indicate that no values have been
* set.
*/
initialize_options(&options);
/*
* Prepare main ssh transport/connection structures
*/
if ((ssh = ssh_alloc_session_state()) == NULL)
fatal("Couldn't allocate session state");
channel_init_channels(ssh);
/* Parse command-line arguments. */
args = argv_assemble(ac, av); /* logged later */
host = NULL;
use_syslog = 0;
logfile = NULL;
argv0 = av[0];
again:
while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
"AB:CD:E:F:GI:J:KL:MNO:P:Q:R:S:TVw:W:XYy")) != -1) { /* HUZdhjruz */
switch (opt) {
case '1':
fatal("SSH protocol v.1 is no longer supported");
break;
case '2':
/* Ignored */
break;
case '4':
options.address_family = AF_INET;
break;
case '6':
options.address_family = AF_INET6;
break;
case 'n':
options.stdin_null = 1;
break;
case 'f':
options.fork_after_authentication = 1;
options.stdin_null = 1;
break;
case 'x':
options.forward_x11 = 0;
break;
case 'X':
options.forward_x11 = 1;
break;
case 'y':
use_syslog = 1;
break;
case 'E':
logfile = optarg;
break;
case 'G':
config_test = 1;
break;
case 'Y':
options.forward_x11 = 1;
options.forward_x11_trusted = 1;
break;
case 'g':
options.fwd_opts.gateway_ports = 1;
break;
case 'O':
if (options.stdio_forward_host != NULL)
fatal("Cannot specify multiplexing "
"command with -W");
else if (muxclient_command != 0)
fatal("Multiplexing command already specified");
if (strcmp(optarg, "check") == 0)
muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
else if (strcmp(optarg, "forward") == 0)
muxclient_command = SSHMUX_COMMAND_FORWARD;
else if (strcmp(optarg, "exit") == 0)
muxclient_command = SSHMUX_COMMAND_TERMINATE;
else if (strcmp(optarg, "stop") == 0)
muxclient_command = SSHMUX_COMMAND_STOP;
else if (strcmp(optarg, "cancel") == 0)
muxclient_command = SSHMUX_COMMAND_CANCEL_FWD;
else if (strcmp(optarg, "proxy") == 0)
muxclient_command = SSHMUX_COMMAND_PROXY;
else
fatal("Invalid multiplex command.");
break;
case 'P':
if (options.tag == NULL)
options.tag = xstrdup(optarg);
break;
case 'Q':
cp = NULL;
if (strcmp(optarg, "cipher") == 0 ||
strcasecmp(optarg, "Ciphers") == 0)
cp = cipher_alg_list('\n', 0);
else if (strcmp(optarg, "cipher-auth") == 0)
cp = cipher_alg_list('\n', 1);
else if (strcmp(optarg, "mac") == 0 ||
strcasecmp(optarg, "MACs") == 0)
cp = mac_alg_list('\n');
else if (strcmp(optarg, "kex") == 0 ||
strcasecmp(optarg, "KexAlgorithms") == 0)
cp = kex_alg_list('\n');
else if (strcmp(optarg, "key") == 0)
cp = sshkey_alg_list(0, 0, 0, '\n');
else if (strcmp(optarg, "key-cert") == 0)
cp = sshkey_alg_list(1, 0, 0, '\n');
else if (strcmp(optarg, "key-plain") == 0)
cp = sshkey_alg_list(0, 1, 0, '\n');
else if (strcmp(optarg, "key-ca-sign") == 0 ||
strcasecmp(optarg, "CASignatureAlgorithms") == 0)
cp = sshkey_alg_list(0, 1, 1, '\n');
else if (strcmp(optarg, "key-sig") == 0 ||
strcasecmp(optarg, "PubkeyAcceptedKeyTypes") == 0 || /* deprecated name */
strcasecmp(optarg, "PubkeyAcceptedAlgorithms") == 0 ||
strcasecmp(optarg, "HostKeyAlgorithms") == 0 ||
strcasecmp(optarg, "HostbasedKeyTypes") == 0 || /* deprecated name */
strcasecmp(optarg, "HostbasedAcceptedKeyTypes") == 0 || /* deprecated name */
strcasecmp(optarg, "HostbasedAcceptedAlgorithms") == 0)
cp = sshkey_alg_list(0, 0, 1, '\n');
else if (strcmp(optarg, "sig") == 0)
cp = sshkey_alg_list(0, 1, 1, '\n');
else if (strcmp(optarg, "protocol-version") == 0)
cp = xstrdup("2");
else if (strcmp(optarg, "compression") == 0) {
cp = xstrdup(compression_alg_list(0));
len = strlen(cp);
for (n = 0; n < len; n++)
if (cp[n] == ',')
cp[n] = '\n';
} else if (strcmp(optarg, "help") == 0) {
cp = xstrdup(
"cipher\ncipher-auth\ncompression\nkex\n"
"key\nkey-cert\nkey-plain\nkey-sig\nmac\n"
"protocol-version\nsig");
}
if (cp == NULL)
fatal("Unsupported query \"%s\"", optarg);
printf("%s\n", cp);
free(cp);
exit(0);
break;
case 'a':
options.forward_agent = 0;
break;
case 'A':
options.forward_agent = 1;
break;
case 'k':
options.gss_deleg_creds = 0;
break;
case 'K':
options.gss_authentication = 1;
options.gss_deleg_creds = 1;
break;
case 'i':
p = tilde_expand_filename(optarg, getuid());
if (stat(p, &st) == -1)
fprintf(stderr, "Warning: Identity file %s "
"not accessible: %s.\n", p,
strerror(errno));
else
add_identity_file(&options, NULL, p, 1);
free(p);
break;
case 'I':
#ifdef ENABLE_PKCS11
free(options.pkcs11_provider);
options.pkcs11_provider = xstrdup(optarg);
#else
fprintf(stderr, "no support for PKCS#11.\n");
#endif
break;
case 'J':
if (options.jump_host != NULL) {
fatal("Only a single -J option is permitted "
"(use commas to separate multiple "
"jump hops)");
}
if (options.proxy_command != NULL)
fatal("Cannot specify -J with ProxyCommand");
if (parse_jump(optarg, &options, 1) == -1)
fatal("Invalid -J argument");
options.proxy_command = xstrdup("none");
break;
case 't':
if (options.request_tty == REQUEST_TTY_YES)
options.request_tty = REQUEST_TTY_FORCE;
else
options.request_tty = REQUEST_TTY_YES;
break;
case 'v':
if (debug_flag == 0) {
debug_flag = 1;
options.log_level = SYSLOG_LEVEL_DEBUG1;
} else {
if (options.log_level < SYSLOG_LEVEL_DEBUG3) {
debug_flag++;
options.log_level++;
}
}
break;
case 'V':
fprintf(stderr, "%s, %s\n",
SSH_RELEASE, SSH_OPENSSL_VERSION);
exit(0);
break;
case 'w':
if (options.tun_open == -1)
options.tun_open = SSH_TUNMODE_DEFAULT;
options.tun_local = a2tun(optarg, &options.tun_remote);
if (options.tun_local == SSH_TUNID_ERR) {
fprintf(stderr,
"Bad tun device '%s'\n", optarg);
exit(255);
}
break;
case 'W':
if (options.stdio_forward_host != NULL)
fatal("stdio forward already specified");
if (muxclient_command != 0)
fatal("Cannot specify stdio forward with -O");
if (parse_forward(&fwd, optarg, 1, 0)) {
options.stdio_forward_host =
fwd.listen_port == PORT_STREAMLOCAL ?
fwd.listen_path : fwd.listen_host;
options.stdio_forward_port = fwd.listen_port;
free(fwd.connect_host);
} else {
fprintf(stderr,
"Bad stdio forwarding specification '%s'\n",
optarg);
exit(255);
}
options.request_tty = REQUEST_TTY_NO;
options.session_type = SESSION_TYPE_NONE;
break;
case 'q':
options.log_level = SYSLOG_LEVEL_QUIET;
break;
case 'e':
if (strlen(optarg) == 2 && optarg[0] == '^' &&
(u_char) optarg[1] >= 64 &&
(u_char) optarg[1] < 128)
options.escape_char = (u_char) optarg[1] & 31;
else if (strlen(optarg) == 1)
options.escape_char = (u_char) optarg[0];
else if (strcmp(optarg, "none") == 0)
options.escape_char = SSH_ESCAPECHAR_NONE;
else {
fprintf(stderr, "Bad escape character '%s'.\n",
optarg);
exit(255);
}
break;
case 'c':
if (!ciphers_valid(*optarg == '+' || *optarg == '^' ?
optarg + 1 : optarg)) {
fprintf(stderr, "Unknown cipher type '%s'\n",
optarg);
exit(255);
}
free(options.ciphers);
options.ciphers = xstrdup(optarg);
break;
case 'm':