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openssh-portable/readconf.c

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/* $OpenBSD: readconf.c,v 1.220 2014/07/15 15:54:14 millert Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* Functions for reading the configuration files.
*
* 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".
*/
#include "includes.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <arpa/inet.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 <stdio.h>
#include <string.h>
#include <unistd.h>
#ifdef HAVE_UTIL_H
#include <util.h>
#endif
#include "xmalloc.h"
#include "ssh.h"
#include "compat.h"
#include "cipher.h"
#include "pathnames.h"
#include "log.h"
#include "key.h"
#include "misc.h"
#include "readconf.h"
#include "match.h"
#include "buffer.h"
#include "kex.h"
#include "mac.h"
#include "uidswap.h"
/* Format of the configuration file:
# Configuration data is parsed as follows:
# 1. command line options
# 2. user-specific file
# 3. system-wide file
# Any configuration value is only changed the first time it is set.
# Thus, host-specific definitions should be at the beginning of the
# configuration file, and defaults at the end.
# Host-specific declarations. These may override anything above. A single
# host may match multiple declarations; these are processed in the order
# that they are given in.
Host *.ngs.fi ngs.fi
User foo
Host fake.com
HostName another.host.name.real.org
User blaah
Port 34289
ForwardX11 no
ForwardAgent no
Host books.com
RemoteForward 9999 shadows.cs.hut.fi:9999
Cipher 3des
Host fascist.blob.com
Port 23123
User tylonen
PasswordAuthentication no
Host puukko.hut.fi
User t35124p
ProxyCommand ssh-proxy %h %p
Host *.fr
PublicKeyAuthentication no
Host *.su
Cipher none
PasswordAuthentication no
Host vpn.fake.com
Tunnel yes
TunnelDevice 3
# Defaults for various options
Host *
ForwardAgent no
ForwardX11 no
PasswordAuthentication yes
RSAAuthentication yes
RhostsRSAAuthentication yes
StrictHostKeyChecking yes
TcpKeepAlive no
IdentityFile ~/.ssh/identity
Port 22
EscapeChar ~
*/
/* Keyword tokens. */
typedef enum {
oBadOption,
oHost, oMatch,
oForwardAgent, oForwardX11, oForwardX11Trusted, oForwardX11Timeout,
oGatewayPorts, oExitOnForwardFailure,
oPasswordAuthentication, oRSAAuthentication,
oChallengeResponseAuthentication, oXAuthLocation,
oIdentityFile, oHostName, oPort, oCipher, oRemoteForward, oLocalForward,
oUser, oEscapeChar, oRhostsRSAAuthentication, oProxyCommand,
oGlobalKnownHostsFile, oUserKnownHostsFile, oConnectionAttempts,
oBatchMode, oCheckHostIP, oStrictHostKeyChecking, oCompression,
oCompressionLevel, oTCPKeepAlive, oNumberOfPasswordPrompts,
oUsePrivilegedPort, oLogLevel, oCiphers, oProtocol, oMacs,
oGlobalKnownHostsFile2, oUserKnownHostsFile2, oPubkeyAuthentication,
oKbdInteractiveAuthentication, oKbdInteractiveDevices, oHostKeyAlias,
oDynamicForward, oPreferredAuthentications, oHostbasedAuthentication,
oHostKeyAlgorithms, oBindAddress, oPKCS11Provider,
oClearAllForwardings, oNoHostAuthenticationForLocalhost,
oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout,
oAddressFamily, oGssAuthentication, oGssDelegateCreds,
oServerAliveInterval, oServerAliveCountMax, oIdentitiesOnly,
oSendEnv, oControlPath, oControlMaster, oControlPersist,
oHashKnownHosts,
oTunnel, oTunnelDevice, oLocalCommand, oPermitLocalCommand,
oVisualHostKey, oUseRoaming,
oKexAlgorithms, oIPQoS, oRequestTTY, oIgnoreUnknown, oProxyUseFdpass,
oCanonicalDomains, oCanonicalizeHostname, oCanonicalizeMaxDots,
oCanonicalizeFallbackLocal, oCanonicalizePermittedCNAMEs,
oStreamLocalBindMask, oStreamLocalBindUnlink,
oIgnoredUnknownOption, oDeprecated, oUnsupported
} OpCodes;
/* Textual representations of the tokens. */
static struct {
const char *name;
OpCodes opcode;
} keywords[] = {
{ "forwardagent", oForwardAgent },
{ "forwardx11", oForwardX11 },
{ "forwardx11trusted", oForwardX11Trusted },
{ "forwardx11timeout", oForwardX11Timeout },
{ "exitonforwardfailure", oExitOnForwardFailure },
{ "xauthlocation", oXAuthLocation },
{ "gatewayports", oGatewayPorts },
{ "useprivilegedport", oUsePrivilegedPort },
{ "rhostsauthentication", oDeprecated },
{ "passwordauthentication", oPasswordAuthentication },
{ "kbdinteractiveauthentication", oKbdInteractiveAuthentication },
{ "kbdinteractivedevices", oKbdInteractiveDevices },
{ "rsaauthentication", oRSAAuthentication },
{ "pubkeyauthentication", oPubkeyAuthentication },
{ "dsaauthentication", oPubkeyAuthentication }, /* alias */
{ "rhostsrsaauthentication", oRhostsRSAAuthentication },
{ "hostbasedauthentication", oHostbasedAuthentication },
{ "challengeresponseauthentication", oChallengeResponseAuthentication },
{ "skeyauthentication", oChallengeResponseAuthentication }, /* alias */
{ "tisauthentication", oChallengeResponseAuthentication }, /* alias */
{ "kerberosauthentication", oUnsupported },
{ "kerberostgtpassing", oUnsupported },
{ "afstokenpassing", oUnsupported },
#if defined(GSSAPI)
{ "gssapiauthentication", oGssAuthentication },
{ "gssapidelegatecredentials", oGssDelegateCreds },
#else
{ "gssapiauthentication", oUnsupported },
{ "gssapidelegatecredentials", oUnsupported },
#endif
{ "fallbacktorsh", oDeprecated },
{ "usersh", oDeprecated },
{ "identityfile", oIdentityFile },
{ "identityfile2", oIdentityFile }, /* obsolete */
{ "identitiesonly", oIdentitiesOnly },
{ "hostname", oHostName },
{ "hostkeyalias", oHostKeyAlias },
{ "proxycommand", oProxyCommand },
{ "port", oPort },
{ "cipher", oCipher },
{ "ciphers", oCiphers },
{ "macs", oMacs },
{ "protocol", oProtocol },
{ "remoteforward", oRemoteForward },
{ "localforward", oLocalForward },
{ "user", oUser },
{ "host", oHost },
{ "match", oMatch },
{ "escapechar", oEscapeChar },
{ "globalknownhostsfile", oGlobalKnownHostsFile },
{ "globalknownhostsfile2", oDeprecated },
{ "userknownhostsfile", oUserKnownHostsFile },
{ "userknownhostsfile2", oDeprecated },
{ "connectionattempts", oConnectionAttempts },
{ "batchmode", oBatchMode },
{ "checkhostip", oCheckHostIP },
{ "stricthostkeychecking", oStrictHostKeyChecking },
{ "compression", oCompression },
{ "compressionlevel", oCompressionLevel },
{ "tcpkeepalive", oTCPKeepAlive },
{ "keepalive", oTCPKeepAlive }, /* obsolete */
{ "numberofpasswordprompts", oNumberOfPasswordPrompts },
{ "loglevel", oLogLevel },
{ "dynamicforward", oDynamicForward },
{ "preferredauthentications", oPreferredAuthentications },
{ "hostkeyalgorithms", oHostKeyAlgorithms },
{ "bindaddress", oBindAddress },
#ifdef ENABLE_PKCS11
{ "smartcarddevice", oPKCS11Provider },
{ "pkcs11provider", oPKCS11Provider },
#else
{ "smartcarddevice", oUnsupported },
{ "pkcs11provider", oUnsupported },
#endif
{ "clearallforwardings", oClearAllForwardings },
{ "enablesshkeysign", oEnableSSHKeysign },
{ "verifyhostkeydns", oVerifyHostKeyDNS },
{ "nohostauthenticationforlocalhost", oNoHostAuthenticationForLocalhost },
{ "rekeylimit", oRekeyLimit },
{ "connecttimeout", oConnectTimeout },
{ "addressfamily", oAddressFamily },
{ "serveraliveinterval", oServerAliveInterval },
{ "serveralivecountmax", oServerAliveCountMax },
{ "sendenv", oSendEnv },
{ "controlpath", oControlPath },
{ "controlmaster", oControlMaster },
{ "controlpersist", oControlPersist },
{ "hashknownhosts", oHashKnownHosts },
{ "tunnel", oTunnel },
{ "tunneldevice", oTunnelDevice },
{ "localcommand", oLocalCommand },
{ "permitlocalcommand", oPermitLocalCommand },
{ "visualhostkey", oVisualHostKey },
{ "useroaming", oUseRoaming },
{ "kexalgorithms", oKexAlgorithms },
{ "ipqos", oIPQoS },
{ "requesttty", oRequestTTY },
{ "proxyusefdpass", oProxyUseFdpass },
{ "canonicaldomains", oCanonicalDomains },
{ "canonicalizefallbacklocal", oCanonicalizeFallbackLocal },
{ "canonicalizehostname", oCanonicalizeHostname },
{ "canonicalizemaxdots", oCanonicalizeMaxDots },
{ "canonicalizepermittedcnames", oCanonicalizePermittedCNAMEs },
{ "streamlocalbindmask", oStreamLocalBindMask },
{ "streamlocalbindunlink", oStreamLocalBindUnlink },
{ "ignoreunknown", oIgnoreUnknown },
{ NULL, oBadOption }
};
/*
* Adds a local TCP/IP port forward to options. Never returns if there is an
* error.
*/
void
add_local_forward(Options *options, const struct Forward *newfwd)
{
struct Forward *fwd;
#ifndef NO_IPPORT_RESERVED_CONCEPT
extern uid_t original_real_uid;
if (newfwd->listen_port < IPPORT_RESERVED && original_real_uid != 0 &&
newfwd->listen_path == NULL)
fatal("Privileged ports can only be forwarded by root.");
#endif
options->local_forwards = xrealloc(options->local_forwards,
options->num_local_forwards + 1,
sizeof(*options->local_forwards));
fwd = &options->local_forwards[options->num_local_forwards++];
fwd->listen_host = newfwd->listen_host;
fwd->listen_port = newfwd->listen_port;
fwd->listen_path = newfwd->listen_path;
fwd->connect_host = newfwd->connect_host;
fwd->connect_port = newfwd->connect_port;
fwd->connect_path = newfwd->connect_path;
}
/*
* Adds a remote TCP/IP port forward to options. Never returns if there is
* an error.
*/
void
add_remote_forward(Options *options, const struct Forward *newfwd)
{
struct Forward *fwd;
options->remote_forwards = xrealloc(options->remote_forwards,
options->num_remote_forwards + 1,
sizeof(*options->remote_forwards));
fwd = &options->remote_forwards[options->num_remote_forwards++];
fwd->listen_host = newfwd->listen_host;
fwd->listen_port = newfwd->listen_port;
fwd->listen_path = newfwd->listen_path;
fwd->connect_host = newfwd->connect_host;
fwd->connect_port = newfwd->connect_port;
fwd->connect_path = newfwd->connect_path;
fwd->handle = newfwd->handle;
fwd->allocated_port = 0;
}
static void
clear_forwardings(Options *options)
{
int i;
for (i = 0; i < options->num_local_forwards; i++) {
free(options->local_forwards[i].listen_host);
free(options->local_forwards[i].listen_path);
free(options->local_forwards[i].connect_host);
free(options->local_forwards[i].connect_path);
}
if (options->num_local_forwards > 0) {
free(options->local_forwards);
options->local_forwards = NULL;
}
options->num_local_forwards = 0;
for (i = 0; i < options->num_remote_forwards; i++) {
free(options->remote_forwards[i].listen_host);
free(options->remote_forwards[i].listen_path);
free(options->remote_forwards[i].connect_host);
free(options->remote_forwards[i].connect_path);
}
if (options->num_remote_forwards > 0) {
free(options->remote_forwards);
options->remote_forwards = NULL;
}
options->num_remote_forwards = 0;
options->tun_open = SSH_TUNMODE_NO;
}
void
add_identity_file(Options *options, const char *dir, const char *filename,
int userprovided)
{
char *path;
int i;
if (options->num_identity_files >= SSH_MAX_IDENTITY_FILES)
fatal("Too many identity files specified (max %d)",
SSH_MAX_IDENTITY_FILES);
if (dir == NULL) /* no dir, filename is absolute */
path = xstrdup(filename);
else
(void)xasprintf(&path, "%.100s%.100s", dir, filename);
/* Avoid registering duplicates */
for (i = 0; i < options->num_identity_files; i++) {
if (options->identity_file_userprovided[i] == userprovided &&
strcmp(options->identity_files[i], path) == 0) {
debug2("%s: ignoring duplicate key %s", __func__, path);
free(path);
return;
}
}
options->identity_file_userprovided[options->num_identity_files] =
userprovided;
options->identity_files[options->num_identity_files++] = path;
}
int
default_ssh_port(void)
{
static int port;
struct servent *sp;
if (port == 0) {
sp = getservbyname(SSH_SERVICE_NAME, "tcp");
port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
}
return port;
}
/*
* Execute a command in a shell.
* Return its exit status or -1 on abnormal exit.
*/
static int
execute_in_shell(const char *cmd)
{
char *shell, *command_string;
pid_t pid;
int devnull, status;
extern uid_t original_real_uid;
if ((shell = getenv("SHELL")) == NULL)
shell = _PATH_BSHELL;
/*
* Use "exec" to avoid "sh -c" processes on some platforms
* (e.g. Solaris)
*/
xasprintf(&command_string, "exec %s", cmd);
/* Need this to redirect subprocess stdin/out */
if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1)
fatal("open(/dev/null): %s", strerror(errno));
debug("Executing command: '%.500s'", cmd);
/* Fork and execute the command. */
if ((pid = fork()) == 0) {
char *argv[4];
/* Child. Permanently give up superuser privileges. */
permanently_drop_suid(original_real_uid);
/* Redirect child stdin and stdout. Leave stderr */
if (dup2(devnull, STDIN_FILENO) == -1)
fatal("dup2: %s", strerror(errno));
if (dup2(devnull, STDOUT_FILENO) == -1)
fatal("dup2: %s", strerror(errno));
if (devnull > STDERR_FILENO)
close(devnull);
closefrom(STDERR_FILENO + 1);
argv[0] = shell;
argv[1] = "-c";
argv[2] = command_string;
argv[3] = NULL;
execv(argv[0], argv);
error("Unable to execute '%.100s': %s", cmd, strerror(errno));
/* Die with signal to make this error apparent to parent. */
signal(SIGTERM, SIG_DFL);
kill(getpid(), SIGTERM);
_exit(1);
}
/* Parent. */
if (pid < 0)
fatal("%s: fork: %.100s", __func__, strerror(errno));
close(devnull);
free(command_string);
while (waitpid(pid, &status, 0) == -1) {
if (errno != EINTR && errno != EAGAIN)
fatal("%s: waitpid: %s", __func__, strerror(errno));
}
if (!WIFEXITED(status)) {
error("command '%.100s' exited abnormally", cmd);
return -1;
}
debug3("command returned status %d", WEXITSTATUS(status));
return WEXITSTATUS(status);
}
/*
* Parse and execute a Match directive.
*/
static int
match_cfg_line(Options *options, char **condition, struct passwd *pw,
const char *host_arg, const char *filename, int linenum)
{
char *arg, *attrib, *cmd, *cp = *condition, *host;
const char *ruser;
int r, port, result = 1, attributes = 0;
size_t len;
char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV];
/*
* Configuration is likely to be incomplete at this point so we
* must be prepared to use default values.
*/
port = options->port <= 0 ? default_ssh_port() : options->port;
ruser = options->user == NULL ? pw->pw_name : options->user;
if (options->hostname != NULL) {
/* NB. Please keep in sync with ssh.c:main() */
host = percent_expand(options->hostname,
"h", host_arg, (char *)NULL);
} else
host = xstrdup(host_arg);
debug3("checking match for '%s' host %s", cp, host);
while ((attrib = strdelim(&cp)) && *attrib != '\0') {
attributes++;
if (strcasecmp(attrib, "all") == 0) {
if (attributes != 1 ||
((arg = strdelim(&cp)) != NULL && *arg != '\0')) {
error("'all' cannot be combined with other "
"Match attributes");
result = -1;
goto out;
}
*condition = cp;
result = 1;
goto out;
}
if ((arg = strdelim(&cp)) == NULL || *arg == '\0') {
error("Missing Match criteria for %s", attrib);
result = -1;
goto out;
}
len = strlen(arg);
if (strcasecmp(attrib, "host") == 0) {
if (match_hostname(host, arg, len) != 1)
result = 0;
else
debug("%.200s line %d: matched 'Host %.100s' ",
filename, linenum, host);
} else if (strcasecmp(attrib, "originalhost") == 0) {
if (match_hostname(host_arg, arg, len) != 1)
result = 0;
else
debug("%.200s line %d: matched "
"'OriginalHost %.100s' ",
filename, linenum, host_arg);
} else if (strcasecmp(attrib, "user") == 0) {
if (match_pattern_list(ruser, arg, len, 0) != 1)
result = 0;
else
debug("%.200s line %d: matched 'User %.100s' ",
filename, linenum, ruser);
} else if (strcasecmp(attrib, "localuser") == 0) {
if (match_pattern_list(pw->pw_name, arg, len, 0) != 1)
result = 0;
else
debug("%.200s line %d: matched "
"'LocalUser %.100s' ",
filename, linenum, pw->pw_name);
} else if (strcasecmp(attrib, "exec") == 0) {
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", port);
cmd = percent_expand(arg,
"L", shorthost,
"d", pw->pw_dir,
"h", host,
"l", thishost,
"n", host_arg,
"p", portstr,
"r", ruser,
"u", pw->pw_name,
(char *)NULL);
if (result != 1) {
/* skip execution if prior predicate failed */
debug("%.200s line %d: skipped exec \"%.100s\"",
filename, linenum, cmd);
} else {
r = execute_in_shell(cmd);
if (r == -1) {
fatal("%.200s line %d: match exec "
"'%.100s' error", filename,
linenum, cmd);
} else if (r == 0) {
debug("%.200s line %d: matched "
"'exec \"%.100s\"'", filename,
linenum, cmd);
} else {
debug("%.200s line %d: no match "
"'exec \"%.100s\"'", filename,
linenum, cmd);
result = 0;
}
}
free(cmd);
} else {
error("Unsupported Match attribute %s", attrib);
result = -1;
goto out;
}
}
if (attributes == 0) {
error("One or more attributes required for Match");
result = -1;
goto out;
}
debug3("match %sfound", result ? "" : "not ");
*condition = cp;
out:
free(host);
return result;
}
/* Check and prepare a domain name: removes trailing '.' and lowercases */
static void
valid_domain(char *name, const char *filename, int linenum)
{
size_t i, l = strlen(name);
u_char c, last = '\0';
if (l == 0)
fatal("%s line %d: empty hostname suffix", filename, linenum);
if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0]))
fatal("%s line %d: hostname suffix \"%.100s\" "
"starts with invalid character", filename, linenum, name);
for (i = 0; i < l; i++) {
c = tolower((u_char)name[i]);
name[i] = (char)c;
if (last == '.' && c == '.')
fatal("%s line %d: hostname suffix \"%.100s\" contains "
"consecutive separators", filename, linenum, name);
if (c != '.' && c != '-' && !isalnum(c) &&
c != '_') /* technically invalid, but common */
fatal("%s line %d: hostname suffix \"%.100s\" contains "
"invalid characters", filename, linenum, name);
last = c;
}
if (name[l - 1] == '.')
name[l - 1] = '\0';
}
/*
* Returns the number of the token pointed to by cp or oBadOption.
*/
static OpCodes
parse_token(const char *cp, const char *filename, int linenum,
const char *ignored_unknown)
{
int i;
for (i = 0; keywords[i].name; i++)
if (strcmp(cp, keywords[i].name) == 0)
return keywords[i].opcode;
if (ignored_unknown != NULL && match_pattern_list(cp, ignored_unknown,
strlen(ignored_unknown), 1) == 1)
return oIgnoredUnknownOption;
error("%s: line %d: Bad configuration option: %s",
filename, linenum, cp);
return oBadOption;
}
/* Multistate option parsing */
struct multistate {
char *key;
int value;
};
static const struct multistate multistate_flag[] = {
{ "true", 1 },
{ "false", 0 },
{ "yes", 1 },
{ "no", 0 },
{ NULL, -1 }
};
static const struct multistate multistate_yesnoask[] = {
{ "true", 1 },
{ "false", 0 },
{ "yes", 1 },
{ "no", 0 },
{ "ask", 2 },
{ NULL, -1 }
};
static const struct multistate multistate_addressfamily[] = {
{ "inet", AF_INET },
{ "inet6", AF_INET6 },
{ "any", AF_UNSPEC },
{ NULL, -1 }
};
static const struct multistate multistate_controlmaster[] = {
{ "true", SSHCTL_MASTER_YES },
{ "yes", SSHCTL_MASTER_YES },
{ "false", SSHCTL_MASTER_NO },
{ "no", SSHCTL_MASTER_NO },
{ "auto", SSHCTL_MASTER_AUTO },
{ "ask", SSHCTL_MASTER_ASK },
{ "autoask", SSHCTL_MASTER_AUTO_ASK },
{ NULL, -1 }
};
static const struct multistate multistate_tunnel[] = {
{ "ethernet", SSH_TUNMODE_ETHERNET },
{ "point-to-point", SSH_TUNMODE_POINTOPOINT },
{ "true", SSH_TUNMODE_DEFAULT },
{ "yes", SSH_TUNMODE_DEFAULT },
{ "false", SSH_TUNMODE_NO },
{ "no", SSH_TUNMODE_NO },
{ NULL, -1 }
};
static const struct multistate multistate_requesttty[] = {
{ "true", REQUEST_TTY_YES },
{ "yes", REQUEST_TTY_YES },
{ "false", REQUEST_TTY_NO },
{ "no", REQUEST_TTY_NO },
{ "force", REQUEST_TTY_FORCE },
{ "auto", REQUEST_TTY_AUTO },
{ NULL, -1 }
};
static const struct multistate multistate_canonicalizehostname[] = {
{ "true", SSH_CANONICALISE_YES },
{ "false", SSH_CANONICALISE_NO },
{ "yes", SSH_CANONICALISE_YES },
{ "no", SSH_CANONICALISE_NO },
{ "always", SSH_CANONICALISE_ALWAYS },
{ NULL, -1 }
};
/*
* Processes a single option line as used in the configuration files. This
* only sets those values that have not already been set.
*/
#define WHITESPACE " \t\r\n"
int
process_config_line(Options *options, struct passwd *pw, const char *host,
char *line, const char *filename, int linenum, int *activep, int userconfig)
{
char *s, **charptr, *endofnumber, *keyword, *arg, *arg2;
char **cpptr, fwdarg[256];
u_int i, *uintptr, max_entries = 0;
int negated, opcode, *intptr, value, value2, cmdline = 0;
LogLevel *log_level_ptr;
long long val64;
size_t len;
struct Forward fwd;
const struct multistate *multistate_ptr;
struct allowed_cname *cname;
if (activep == NULL) { /* We are processing a command line directive */
cmdline = 1;
activep = &cmdline;
}
/* Strip trailing whitespace */
for (len = strlen(line) - 1; len > 0; len--) {
if (strchr(WHITESPACE, line[len]) == NULL)
break;
line[len] = '\0';
}
s = line;
/* Get the keyword. (Each line is supposed to begin with a keyword). */
if ((keyword = strdelim(&s)) == NULL)
return 0;
/* Ignore leading whitespace. */
if (*keyword == '\0')
keyword = strdelim(&s);
if (keyword == NULL || !*keyword || *keyword == '\n' || *keyword == '#')
return 0;
/* Match lowercase keyword */
lowercase(keyword);
opcode = parse_token(keyword, filename, linenum,
options->ignored_unknown);
switch (opcode) {
case oBadOption:
/* don't panic, but count bad options */
return -1;
/* NOTREACHED */
case oIgnoredUnknownOption:
debug("%s line %d: Ignored unknown option \"%s\"",
filename, linenum, keyword);
return 0;
case oConnectTimeout:
intptr = &options->connection_timeout;
parse_time:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%s line %d: missing time value.",
filename, linenum);
if ((value = convtime(arg)) == -1)
fatal("%s line %d: invalid time value.",
filename, linenum);
if (*activep && *intptr == -1)
*intptr = value;
break;
case oForwardAgent:
intptr = &options->forward_agent;
parse_flag:
multistate_ptr = multistate_flag;
parse_multistate:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%s line %d: missing argument.",
filename, linenum);
value = -1;
for (i = 0; multistate_ptr[i].key != NULL; i++) {
if (strcasecmp(arg, multistate_ptr[i].key) == 0) {
value = multistate_ptr[i].value;
break;
}
}
if (value == -1)
fatal("%s line %d: unsupported option \"%s\".",
filename, linenum, arg);
if (*activep && *intptr == -1)
*intptr = value;
break;
case oForwardX11:
intptr = &options->forward_x11;
goto parse_flag;
case oForwardX11Trusted:
intptr = &options->forward_x11_trusted;
goto parse_flag;
case oForwardX11Timeout:
intptr = &options->forward_x11_timeout;
goto parse_time;
case oGatewayPorts:
intptr = &options->fwd_opts.gateway_ports;
goto parse_flag;
case oExitOnForwardFailure:
intptr = &options->exit_on_forward_failure;
goto parse_flag;
case oUsePrivilegedPort:
intptr = &options->use_privileged_port;
goto parse_flag;
case oPasswordAuthentication:
intptr = &options->password_authentication;
goto parse_flag;
case oKbdInteractiveAuthentication:
intptr = &options->kbd_interactive_authentication;
goto parse_flag;
case oKbdInteractiveDevices:
charptr = &options->kbd_interactive_devices;
goto parse_string;
case oPubkeyAuthentication:
intptr = &options->pubkey_authentication;
goto parse_flag;
case oRSAAuthentication:
intptr = &options->rsa_authentication;
goto parse_flag;
case oRhostsRSAAuthentication:
intptr = &options->rhosts_rsa_authentication;
goto parse_flag;
case oHostbasedAuthentication:
intptr = &options->hostbased_authentication;
goto parse_flag;
case oChallengeResponseAuthentication:
intptr = &options->challenge_response_authentication;
goto parse_flag;
case oGssAuthentication:
intptr = &options->gss_authentication;
goto parse_flag;
case oGssDelegateCreds:
intptr = &options->gss_deleg_creds;
goto parse_flag;
case oBatchMode:
intptr = &options->batch_mode;
goto parse_flag;
case oCheckHostIP:
intptr = &options->check_host_ip;
goto parse_flag;
case oVerifyHostKeyDNS:
intptr = &options->verify_host_key_dns;
multistate_ptr = multistate_yesnoask;
goto parse_multistate;
case oStrictHostKeyChecking:
intptr = &options->strict_host_key_checking;
multistate_ptr = multistate_yesnoask;
goto parse_multistate;
case oCompression:
intptr = &options->compression;
goto parse_flag;
case oTCPKeepAlive:
intptr = &options->tcp_keep_alive;
goto parse_flag;
case oNoHostAuthenticationForLocalhost:
intptr = &options->no_host_authentication_for_localhost;
goto parse_flag;
case oNumberOfPasswordPrompts:
intptr = &options->number_of_password_prompts;
goto parse_int;
case oCompressionLevel:
intptr = &options->compression_level;
goto parse_int;
case oRekeyLimit:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename,
linenum);
if (strcmp(arg, "default") == 0) {
val64 = 0;
} else {
if (scan_scaled(arg, &val64) == -1)
fatal("%.200s line %d: Bad number '%s': %s",
filename, linenum, arg, strerror(errno));
/* check for too-large or too-small limits */
if (val64 > UINT_MAX)
fatal("%.200s line %d: RekeyLimit too large",
filename, linenum);
if (val64 != 0 && val64 < 16)
fatal("%.200s line %d: RekeyLimit too small",
filename, linenum);
}
if (*activep && options->rekey_limit == -1)
options->rekey_limit = (u_int32_t)val64;
if (s != NULL) { /* optional rekey interval present */
if (strcmp(s, "none") == 0) {
(void)strdelim(&s); /* discard */
break;
}
intptr = &options->rekey_interval;
goto parse_time;
}
break;
case oIdentityFile:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (*activep) {
intptr = &options->num_identity_files;
if (*intptr >= SSH_MAX_IDENTITY_FILES)
fatal("%.200s line %d: Too many identity files specified (max %d).",
filename, linenum, SSH_MAX_IDENTITY_FILES);
add_identity_file(options, NULL, arg, userconfig);
}
break;
case oXAuthLocation:
charptr=&options->xauth_location;
goto parse_string;
case oUser:
charptr = &options->user;
parse_string:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.",
filename, linenum);
if (*activep && *charptr == NULL)
*charptr = xstrdup(arg);
break;
case oGlobalKnownHostsFile:
cpptr = (char **)&options->system_hostfiles;
uintptr = &options->num_system_hostfiles;
max_entries = SSH_MAX_HOSTS_FILES;
parse_char_array:
if (*activep && *uintptr == 0) {
while ((arg = strdelim(&s)) != NULL && *arg != '\0') {
if ((*uintptr) >= max_entries)
fatal("%s line %d: "
"too many authorized keys files.",
filename, linenum);
cpptr[(*uintptr)++] = xstrdup(arg);
}
}
return 0;
case oUserKnownHostsFile:
cpptr = (char **)&options->user_hostfiles;
uintptr = &options->num_user_hostfiles;
max_entries = SSH_MAX_HOSTS_FILES;
goto parse_char_array;
case oHostName:
charptr = &options->hostname;
goto parse_string;
case oHostKeyAlias:
charptr = &options->host_key_alias;
goto parse_string;
case oPreferredAuthentications:
charptr = &options->preferred_authentications;
goto parse_string;
case oBindAddress:
charptr = &options->bind_address;
goto parse_string;
case oPKCS11Provider:
charptr = &options->pkcs11_provider;
goto parse_string;
case oProxyCommand:
charptr = &options->proxy_command;
parse_command:
if (s == NULL)
fatal("%.200s line %d: Missing argument.", filename, linenum);
len = strspn(s, WHITESPACE "=");
if (*activep && *charptr == NULL)
*charptr = xstrdup(s + len);
return 0;
case oPort:
intptr = &options->port;
parse_int:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (arg[0] < '0' || arg[0] > '9')
fatal("%.200s line %d: Bad number.", filename, linenum);
/* Octal, decimal, or hex format? */
value = strtol(arg, &endofnumber, 0);
if (arg == endofnumber)
fatal("%.200s line %d: Bad number.", filename, linenum);
if (*activep && *intptr == -1)
*intptr = value;
break;
case oConnectionAttempts:
intptr = &options->connection_attempts;
goto parse_int;
case oCipher:
intptr = &options->cipher;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
value = cipher_number(arg);
if (value == -1)
fatal("%.200s line %d: Bad cipher '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && *intptr == -1)
*intptr = value;
break;
case oCiphers:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (!ciphers_valid(arg))
fatal("%.200s line %d: Bad SSH2 cipher spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && options->ciphers == NULL)
options->ciphers = xstrdup(arg);
break;
case oMacs:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (!mac_valid(arg))
fatal("%.200s line %d: Bad SSH2 Mac spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && options->macs == NULL)
options->macs = xstrdup(arg);
break;
case oKexAlgorithms:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.",
filename, linenum);
if (!kex_names_valid(arg))
fatal("%.200s line %d: Bad SSH2 KexAlgorithms '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && options->kex_algorithms == NULL)
options->kex_algorithms = xstrdup(arg);
break;
case oHostKeyAlgorithms:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (!key_names_valid2(arg))
fatal("%.200s line %d: Bad protocol 2 host key algorithms '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && options->hostkeyalgorithms == NULL)
options->hostkeyalgorithms = xstrdup(arg);
break;
case oProtocol:
intptr = &options->protocol;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
value = proto_spec(arg);
if (value == SSH_PROTO_UNKNOWN)
fatal("%.200s line %d: Bad protocol spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && *intptr == SSH_PROTO_UNKNOWN)
*intptr = value;
break;
case oLogLevel:
log_level_ptr = &options->log_level;
arg = strdelim(&s);
value = log_level_number(arg);
if (value == SYSLOG_LEVEL_NOT_SET)
fatal("%.200s line %d: unsupported log level '%s'",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && *log_level_ptr == SYSLOG_LEVEL_NOT_SET)
*log_level_ptr = (LogLevel) value;
break;
case oLocalForward:
case oRemoteForward:
case oDynamicForward:
arg = strdelim(&s);
if (arg == NULL || *arg == '\0')
fatal("%.200s line %d: Missing port argument.",
filename, linenum);
if (opcode == oLocalForward ||
opcode == oRemoteForward) {
arg2 = strdelim(&s);
if (arg2 == NULL || *arg2 == '\0')
fatal("%.200s line %d: Missing target argument.",
filename, linenum);
/* construct a string for parse_forward */
snprintf(fwdarg, sizeof(fwdarg), "%s:%s", arg, arg2);
} else if (opcode == oDynamicForward) {
strlcpy(fwdarg, arg, sizeof(fwdarg));
}
if (parse_forward(&fwd, fwdarg,
opcode == oDynamicForward ? 1 : 0,
opcode == oRemoteForward ? 1 : 0) == 0)
fatal("%.200s line %d: Bad forwarding specification.",
filename, linenum);
if (*activep) {
if (opcode == oLocalForward ||
opcode == oDynamicForward)
add_local_forward(options, &fwd);
else if (opcode == oRemoteForward)
add_remote_forward(options, &fwd);
}
break;
case oClearAllForwardings:
intptr = &options->clear_forwardings;
goto parse_flag;
case oHost:
if (cmdline)
fatal("Host directive not supported as a command-line "
"option");
*activep = 0;
arg2 = NULL;
while ((arg = strdelim(&s)) != NULL && *arg != '\0') {
negated = *arg == '!';
if (negated)
arg++;
if (match_pattern(host, arg)) {
if (negated) {
debug("%.200s line %d: Skipping Host "
"block because of negated match "
"for %.100s", filename, linenum,
arg);
*activep = 0;
break;
}
if (!*activep)
arg2 = arg; /* logged below */
*activep = 1;
}
}
if (*activep)
debug("%.200s line %d: Applying options for %.100s",
filename, linenum, arg2);
/* Avoid garbage check below, as strdelim is done. */
return 0;
case oMatch:
if (cmdline)
fatal("Host directive not supported as a command-line "
"option");
value = match_cfg_line(options, &s, pw, host,
filename, linenum);
if (value < 0)
fatal("%.200s line %d: Bad Match condition", filename,
linenum);
*activep = value;
break;
case oEscapeChar:
intptr = &options->escape_char;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (arg[0] == '^' && arg[2] == 0 &&
(u_char) arg[1] >= 64 && (u_char) arg[1] < 128)
value = (u_char) arg[1] & 31;
else if (strlen(arg) == 1)
value = (u_char) arg[0];
else if (strcmp(arg, "none") == 0)
value = SSH_ESCAPECHAR_NONE;
else {
fatal("%.200s line %d: Bad escape character.",
filename, linenum);
/* NOTREACHED */
value = 0; /* Avoid compiler warning. */
}
if (*activep && *intptr == -1)
*intptr = value;
break;
case oAddressFamily:
intptr = &options->address_family;
multistate_ptr = multistate_addressfamily;
goto parse_multistate;
case oEnableSSHKeysign:
intptr = &options->enable_ssh_keysign;
goto parse_flag;
case oIdentitiesOnly:
intptr = &options->identities_only;
goto parse_flag;
case oServerAliveInterval:
intptr = &options->server_alive_interval;
goto parse_time;
case oServerAliveCountMax:
intptr = &options->server_alive_count_max;
goto parse_int;
case oSendEnv:
while ((arg = strdelim(&s)) != NULL && *arg != '\0') {
if (strchr(arg, '=') != NULL)
fatal("%s line %d: Invalid environment name.",
filename, linenum);
if (!*activep)
continue;
if (options->num_send_env >= MAX_SEND_ENV)
fatal("%s line %d: too many send env.",
filename, linenum);
options->send_env[options->num_send_env++] =
xstrdup(arg);
}
break;
case oControlPath:
charptr = &options->control_path;
goto parse_string;
case oControlMaster:
intptr = &options->control_master;
multistate_ptr = multistate_controlmaster;
goto parse_multistate;
case oControlPersist:
/* no/false/yes/true, or a time spec */
intptr = &options->control_persist;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing ControlPersist"
" argument.", filename, linenum);
value = 0;
value2 = 0; /* timeout */
if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0)
value = 0;
else if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0)
value = 1;
else if ((value2 = convtime(arg)) >= 0)
value = 1;
else
fatal("%.200s line %d: Bad ControlPersist argument.",
filename, linenum);
if (*activep && *intptr == -1) {
*intptr = value;
options->control_persist_timeout = value2;
}
break;
case oHashKnownHosts:
intptr = &options->hash_known_hosts;
goto parse_flag;
case oTunnel:
intptr = &options->tun_open;
multistate_ptr = multistate_tunnel;
goto parse_multistate;
case oTunnelDevice:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
value = a2tun(arg, &value2);
if (value == SSH_TUNID_ERR)
fatal("%.200s line %d: Bad tun device.", filename, linenum);
if (*activep) {
options->tun_local = value;
options->tun_remote = value2;
}
break;
case oLocalCommand:
charptr = &options->local_command;
goto parse_command;
case oPermitLocalCommand:
intptr = &options->permit_local_command;
goto parse_flag;
case oVisualHostKey:
intptr = &options->visual_host_key;
goto parse_flag;
case oIPQoS:
arg = strdelim(&s);
if ((value = parse_ipqos(arg)) == -1)
fatal("%s line %d: Bad IPQoS value: %s",
filename, linenum, arg);
arg = strdelim(&s);
if (arg == NULL)
value2 = value;
else if ((value2 = parse_ipqos(arg)) == -1)
fatal("%s line %d: Bad IPQoS value: %s",
filename, linenum, arg);
if (*activep) {
options->ip_qos_interactive = value;
options->ip_qos_bulk = value2;
}
break;
case oUseRoaming:
intptr = &options->use_roaming;
goto parse_flag;
case oRequestTTY:
intptr = &options->request_tty;
multistate_ptr = multistate_requesttty;
goto parse_multistate;
case oIgnoreUnknown:
charptr = &options->ignored_unknown;
goto parse_string;
case oProxyUseFdpass:
intptr = &options->proxy_use_fdpass;
goto parse_flag;
case oCanonicalDomains:
value = options->num_canonical_domains != 0;
while ((arg = strdelim(&s)) != NULL && *arg != '\0') {
valid_domain(arg, filename, linenum);
if (!*activep || value)
continue;
if (options->num_canonical_domains >= MAX_CANON_DOMAINS)
fatal("%s line %d: too many hostname suffixes.",
filename, linenum);
options->canonical_domains[
options->num_canonical_domains++] = xstrdup(arg);
}
break;
case oCanonicalizePermittedCNAMEs:
value = options->num_permitted_cnames != 0;
while ((arg = strdelim(&s)) != NULL && *arg != '\0') {
/* Either '*' for everything or 'list:list' */
if (strcmp(arg, "*") == 0)
arg2 = arg;
else {
lowercase(arg);
if ((arg2 = strchr(arg, ':')) == NULL ||
arg2[1] == '\0') {
fatal("%s line %d: "
"Invalid permitted CNAME \"%s\"",
filename, linenum, arg);
}
*arg2 = '\0';
arg2++;
}
if (!*activep || value)
continue;
if (options->num_permitted_cnames >= MAX_CANON_DOMAINS)
fatal("%s line %d: too many permitted CNAMEs.",
filename, linenum);
cname = options->permitted_cnames +
options->num_permitted_cnames++;
cname->source_list = xstrdup(arg);
cname->target_list = xstrdup(arg2);
}
break;
case oCanonicalizeHostname:
intptr = &options->canonicalize_hostname;
multistate_ptr = multistate_canonicalizehostname;
goto parse_multistate;
case oCanonicalizeMaxDots:
intptr = &options->canonicalize_max_dots;
goto parse_int;
case oCanonicalizeFallbackLocal:
intptr = &options->canonicalize_fallback_local;
goto parse_flag;
case oStreamLocalBindMask:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing StreamLocalBindMask argument.", filename, linenum);
/* Parse mode in octal format */
value = strtol(arg, &endofnumber, 8);
if (arg == endofnumber || value < 0 || value > 0777)
fatal("%.200s line %d: Bad mask.", filename, linenum);
options->fwd_opts.streamlocal_bind_mask = (mode_t)value;
break;
case oStreamLocalBindUnlink:
intptr = &options->fwd_opts.streamlocal_bind_unlink;
goto parse_flag;
case oDeprecated:
debug("%s line %d: Deprecated option \"%s\"",
filename, linenum, keyword);
return 0;
case oUnsupported:
error("%s line %d: Unsupported option \"%s\"",
filename, linenum, keyword);
return 0;
default:
fatal("process_config_line: Unimplemented opcode %d", opcode);
}
/* Check that there is no garbage at end of line. */
if ((arg = strdelim(&s)) != NULL && *arg != '\0') {
fatal("%.200s line %d: garbage at end of line; \"%.200s\".",
filename, linenum, arg);
}
return 0;
}
/*
* Reads the config file and modifies the options accordingly. Options
* should already be initialized before this call. This never returns if
* there is an error. If the file does not exist, this returns 0.
*/
int
read_config_file(const char *filename, struct passwd *pw, const char *host,
Options *options, int flags)
{
FILE *f;
char line[1024];
int active, linenum;
int bad_options = 0;
if ((f = fopen(filename, "r")) == NULL)
return 0;
if (flags & SSHCONF_CHECKPERM) {
struct stat sb;
if (fstat(fileno(f), &sb) == -1)
fatal("fstat %s: %s", filename, strerror(errno));
if (((sb.st_uid != 0 && sb.st_uid != getuid()) ||
(sb.st_mode & 022) != 0))
fatal("Bad owner or permissions on %s", filename);
}
debug("Reading configuration data %.200s", filename);
/*
* Mark that we are now processing the options. This flag is turned
* on/off by Host specifications.
*/
active = 1;
linenum = 0;
while (fgets(line, sizeof(line), f)) {
/* Update line number counter. */
linenum++;
if (process_config_line(options, pw, host, line, filename,
linenum, &active, flags & SSHCONF_USERCONF) != 0)
bad_options++;
}
fclose(f);
if (bad_options > 0)
fatal("%s: terminating, %d bad configuration options",
filename, bad_options);
return 1;
}
/* Returns 1 if a string option is unset or set to "none" or 0 otherwise. */
int
option_clear_or_none(const char *o)
{
return o == NULL || strcasecmp(o, "none") == 0;
}
/*
* Initializes options to special values that indicate that they have not yet
* been set. Read_config_file will only set options with this value. Options
* are processed in the following order: command line, user config file,
* system config file. Last, fill_default_options is called.
*/
void
initialize_options(Options * options)
{
memset(options, 'X', sizeof(*options));
options->forward_agent = -1;
options->forward_x11 = -1;
options->forward_x11_trusted = -1;
options->forward_x11_timeout = -1;
options->exit_on_forward_failure = -1;
options->xauth_location = NULL;
options->fwd_opts.gateway_ports = -1;
options->fwd_opts.streamlocal_bind_mask = (mode_t)-1;
options->fwd_opts.streamlocal_bind_unlink = -1;
options->use_privileged_port = -1;
options->rsa_authentication = -1;
options->pubkey_authentication = -1;
options->challenge_response_authentication = -1;
options->gss_authentication = -1;
options->gss_deleg_creds = -1;
options->password_authentication = -1;
options->kbd_interactive_authentication = -1;
options->kbd_interactive_devices = NULL;
options->rhosts_rsa_authentication = -1;
options->hostbased_authentication = -1;
options->batch_mode = -1;
options->check_host_ip = -1;
options->strict_host_key_checking = -1;
options->compression = -1;
options->tcp_keep_alive = -1;
options->compression_level = -1;
options->port = -1;
options->address_family = -1;
options->connection_attempts = -1;
options->connection_timeout = -1;
options->number_of_password_prompts = -1;
options->cipher = -1;
options->ciphers = NULL;
options->macs = NULL;
options->kex_algorithms = NULL;
options->hostkeyalgorithms = NULL;
options->protocol = SSH_PROTO_UNKNOWN;
options->num_identity_files = 0;
options->hostname = NULL;
options->host_key_alias = NULL;
options->proxy_command = NULL;
options->user = NULL;
options->escape_char = -1;
options->num_system_hostfiles = 0;
options->num_user_hostfiles = 0;
options->local_forwards = NULL;
options->num_local_forwards = 0;
options->remote_forwards = NULL;
options->num_remote_forwards = 0;
options->clear_forwardings = -1;
options->log_level = SYSLOG_LEVEL_NOT_SET;
options->preferred_authentications = NULL;
options->bind_address = NULL;
options->pkcs11_provider = NULL;
options->enable_ssh_keysign = - 1;
options->no_host_authentication_for_localhost = - 1;
options->identities_only = - 1;
options->rekey_limit = - 1;
options->rekey_interval = -1;
options->verify_host_key_dns = -1;
options->server_alive_interval = -1;
options->server_alive_count_max = -1;
options->num_send_env = 0;
options->control_path = NULL;
options->control_master = -1;
options->control_persist = -1;
options->control_persist_timeout = 0;
options->hash_known_hosts = -1;
options->tun_open = -1;
options->tun_local = -1;
options->tun_remote = -1;
options->local_command = NULL;
options->permit_local_command = -1;
options->use_roaming = -1;
options->visual_host_key = -1;
options->ip_qos_interactive = -1;
options->ip_qos_bulk = -1;
options->request_tty = -1;
options->proxy_use_fdpass = -1;
options->ignored_unknown = NULL;
options->num_canonical_domains = 0;
options->num_permitted_cnames = 0;
options->canonicalize_max_dots = -1;
options->canonicalize_fallback_local = -1;
options->canonicalize_hostname = -1;
}
/*
* A petite version of fill_default_options() that just fills the options
* needed for hostname canonicalization to proceed.
*/
void
fill_default_options_for_canonicalization(Options *options)
{
if (options->canonicalize_max_dots == -1)
options->canonicalize_max_dots = 1;
if (options->canonicalize_fallback_local == -1)
options->canonicalize_fallback_local = 1;
if (options->canonicalize_hostname == -1)
options->canonicalize_hostname = SSH_CANONICALISE_NO;
}
/*
* Called after processing other sources of option data, this fills those
* options for which no value has been specified with their default values.
*/
void
fill_default_options(Options * options)
{
if (options->forward_agent == -1)
options->forward_agent = 0;
if (options->forward_x11 == -1)
options->forward_x11 = 0;
if (options->forward_x11_trusted == -1)
options->forward_x11_trusted = 0;
if (options->forward_x11_timeout == -1)
options->forward_x11_timeout = 1200;
if (options->exit_on_forward_failure == -1)
options->exit_on_forward_failure = 0;
if (options->xauth_location == NULL)
options->xauth_location = _PATH_XAUTH;
if (options->fwd_opts.gateway_ports == -1)
options->fwd_opts.gateway_ports = 0;
if (options->fwd_opts.streamlocal_bind_mask == (mode_t)-1)
options->fwd_opts.streamlocal_bind_mask = 0177;
if (options->fwd_opts.streamlocal_bind_unlink == -1)
options->fwd_opts.streamlocal_bind_unlink = 0;
if (options->use_privileged_port == -1)
options->use_privileged_port = 0;
if (options->rsa_authentication == -1)
options->rsa_authentication = 1;
if (options->pubkey_authentication == -1)
options->pubkey_authentication = 1;
if (options->challenge_response_authentication == -1)
options->challenge_response_authentication = 1;
if (options->gss_authentication == -1)
options->gss_authentication = 0;
if (options->gss_deleg_creds == -1)
options->gss_deleg_creds = 0;
if (options->password_authentication == -1)
options->password_authentication = 1;
if (options->kbd_interactive_authentication == -1)
options->kbd_interactive_authentication = 1;
if (options->rhosts_rsa_authentication == -1)
options->rhosts_rsa_authentication = 0;
if (options->hostbased_authentication == -1)
options->hostbased_authentication = 0;
if (options->batch_mode == -1)
options->batch_mode = 0;
if (options->check_host_ip == -1)
options->check_host_ip = 1;
if (options->strict_host_key_checking == -1)
options->strict_host_key_checking = 2; /* 2 is default */
if (options->compression == -1)
options->compression = 0;
if (options->tcp_keep_alive == -1)
options->tcp_keep_alive = 1;
if (options->compression_level == -1)
options->compression_level = 6;
if (options->port == -1)
options->port = 0; /* Filled in ssh_connect. */
if (options->address_family == -1)
options->address_family = AF_UNSPEC;
if (options->connection_attempts == -1)
options->connection_attempts = 1;
if (options->number_of_password_prompts == -1)
options->number_of_password_prompts = 3;
/* Selected in ssh_login(). */
if (options->cipher == -1)
options->cipher = SSH_CIPHER_NOT_SET;
/* options->ciphers, default set in myproposals.h */
/* options->macs, default set in myproposals.h */
/* options->kex_algorithms, default set in myproposals.h */
/* options->hostkeyalgorithms, default set in myproposals.h */
if (options->protocol == SSH_PROTO_UNKNOWN)
options->protocol = SSH_PROTO_2;
if (options->num_identity_files == 0) {
if (options->protocol & SSH_PROTO_1) {
add_identity_file(options, "~/",
_PATH_SSH_CLIENT_IDENTITY, 0);
}
if (options->protocol & SSH_PROTO_2) {
add_identity_file(options, "~/",
_PATH_SSH_CLIENT_ID_RSA, 0);
add_identity_file(options, "~/",
_PATH_SSH_CLIENT_ID_DSA, 0);
#ifdef OPENSSL_HAS_ECC
add_identity_file(options, "~/",
_PATH_SSH_CLIENT_ID_ECDSA, 0);
#endif
add_identity_file(options, "~/",
_PATH_SSH_CLIENT_ID_ED25519, 0);
}
}
if (options->escape_char == -1)
options->escape_char = '~';
if (options->num_system_hostfiles == 0) {
options->system_hostfiles[options->num_system_hostfiles++] =
xstrdup(_PATH_SSH_SYSTEM_HOSTFILE);
options->system_hostfiles[options->num_system_hostfiles++] =
xstrdup(_PATH_SSH_SYSTEM_HOSTFILE2);
}
if (options->num_user_hostfiles == 0) {
options->user_hostfiles[options->num_user_hostfiles++] =
xstrdup(_PATH_SSH_USER_HOSTFILE);
options->user_hostfiles[options->num_user_hostfiles++] =
xstrdup(_PATH_SSH_USER_HOSTFILE2);
}
if (options->log_level == SYSLOG_LEVEL_NOT_SET)
options->log_level = SYSLOG_LEVEL_INFO;
if (options->clear_forwardings == 1)
clear_forwardings(options);
if (options->no_host_authentication_for_localhost == - 1)
options->no_host_authentication_for_localhost = 0;
if (options->identities_only == -1)
options->identities_only = 0;
if (options->enable_ssh_keysign == -1)
options->enable_ssh_keysign = 0;
if (options->rekey_limit == -1)
options->rekey_limit = 0;
if (options->rekey_interval == -1)
options->rekey_interval = 0;
if (options->verify_host_key_dns == -1)
options->verify_host_key_dns = 0;
if (options->server_alive_interval == -1)
options->server_alive_interval = 0;
if (options->server_alive_count_max == -1)
options->server_alive_count_max = 3;
if (options->control_master == -1)
options->control_master = 0;
if (options->control_persist == -1) {
options->control_persist = 0;
options->control_persist_timeout = 0;
}
if (options->hash_known_hosts == -1)
options->hash_known_hosts = 0;
if (options->tun_open == -1)
options->tun_open = SSH_TUNMODE_NO;
if (options->tun_local == -1)
options->tun_local = SSH_TUNID_ANY;
if (options->tun_remote == -1)
options->tun_remote = SSH_TUNID_ANY;
if (options->permit_local_command == -1)
options->permit_local_command = 0;
if (options->use_roaming == -1)
options->use_roaming = 1;
if (options->visual_host_key == -1)
options->visual_host_key = 0;
if (options->ip_qos_interactive == -1)
options->ip_qos_interactive = IPTOS_LOWDELAY;
if (options->ip_qos_bulk == -1)
options->ip_qos_bulk = IPTOS_THROUGHPUT;
if (options->request_tty == -1)
options->request_tty = REQUEST_TTY_AUTO;
if (options->proxy_use_fdpass == -1)
options->proxy_use_fdpass = 0;
if (options->canonicalize_max_dots == -1)
options->canonicalize_max_dots = 1;
if (options->canonicalize_fallback_local == -1)
options->canonicalize_fallback_local = 1;
if (options->canonicalize_hostname == -1)
options->canonicalize_hostname = SSH_CANONICALISE_NO;
#define CLEAR_ON_NONE(v) \
do { \
if (option_clear_or_none(v)) { \
free(v); \
v = NULL; \
} \
} while(0)
CLEAR_ON_NONE(options->local_command);
CLEAR_ON_NONE(options->proxy_command);
CLEAR_ON_NONE(options->control_path);
/* options->user will be set in the main program if appropriate */
/* options->hostname will be set in the main program if appropriate */
/* options->host_key_alias should not be set by default */
/* options->preferred_authentications will be set in ssh */
}
struct fwdarg {
char *arg;
int ispath;
};
/*
* parse_fwd_field
* parses the next field in a port forwarding specification.
* sets fwd to the parsed field and advances p past the colon
* or sets it to NULL at end of string.
* returns 0 on success, else non-zero.
*/
static int
parse_fwd_field(char **p, struct fwdarg *fwd)
{
char *ep, *cp = *p;
int ispath = 0;
if (*cp == '\0') {
*p = NULL;
return -1; /* end of string */
}
/*
* A field escaped with square brackets is used literally.
* XXX - allow ']' to be escaped via backslash?
*/
if (*cp == '[') {
/* find matching ']' */
for (ep = cp + 1; *ep != ']' && *ep != '\0'; ep++) {
if (*ep == '/')
ispath = 1;
}
/* no matching ']' or not at end of field. */
if (ep[0] != ']' || (ep[1] != ':' && ep[1] != '\0'))
return -1;
/* NUL terminate the field and advance p past the colon */
*ep++ = '\0';
if (*ep != '\0')
*ep++ = '\0';
fwd->arg = cp + 1;
fwd->ispath = ispath;
*p = ep;
return 0;
}
for (cp = *p; *cp != '\0'; cp++) {
switch (*cp) {
case '\\':
memmove(cp, cp + 1, strlen(cp + 1) + 1);
cp++;
break;
case '/':
ispath = 1;
break;
case ':':
*cp++ = '\0';
goto done;
}
}
done:
fwd->arg = *p;
fwd->ispath = ispath;
*p = cp;
return 0;
}
/*
* parse_forward
* parses a string containing a port forwarding specification of the form:
* dynamicfwd == 0
* [listenhost:]listenport|listenpath:connecthost:connectport|connectpath
* listenpath:connectpath
* dynamicfwd == 1
* [listenhost:]listenport
* returns number of arguments parsed or zero on error
*/
int
parse_forward(struct Forward *fwd, const char *fwdspec, int dynamicfwd, int remotefwd)
{
struct fwdarg fwdargs[4];
char *p, *cp;
int i;
memset(fwd, 0, sizeof(*fwd));
memset(fwdargs, 0, sizeof(fwdargs));
cp = p = xstrdup(fwdspec);
/* skip leading spaces */
while (isspace((u_char)*cp))
cp++;
for (i = 0; i < 4; ++i) {
if (parse_fwd_field(&cp, &fwdargs[i]) != 0)
break;
}
/* Check for trailing garbage */
if (cp != NULL && *cp != '\0') {
i = 0; /* failure */
}
switch (i) {
case 1:
if (fwdargs[0].ispath) {
fwd->listen_path = xstrdup(fwdargs[0].arg);
fwd->listen_port = PORT_STREAMLOCAL;
} else {
fwd->listen_host = NULL;
fwd->listen_port = a2port(fwdargs[0].arg);
}
fwd->connect_host = xstrdup("socks");
break;
case 2:
if (fwdargs[0].ispath && fwdargs[1].ispath) {
fwd->listen_path = xstrdup(fwdargs[0].arg);
fwd->listen_port = PORT_STREAMLOCAL;
fwd->connect_path = xstrdup(fwdargs[1].arg);
fwd->connect_port = PORT_STREAMLOCAL;
} else if (fwdargs[1].ispath) {
fwd->listen_host = NULL;
fwd->listen_port = a2port(fwdargs[0].arg);
fwd->connect_path = xstrdup(fwdargs[1].arg);
fwd->connect_port = PORT_STREAMLOCAL;
} else {
fwd->listen_host = xstrdup(fwdargs[0].arg);
fwd->listen_port = a2port(fwdargs[1].arg);
fwd->connect_host = xstrdup("socks");
}
break;
case 3:
if (fwdargs[0].ispath) {
fwd->listen_path = xstrdup(fwdargs[0].arg);
fwd->listen_port = PORT_STREAMLOCAL;
fwd->connect_host = xstrdup(fwdargs[1].arg);
fwd->connect_port = a2port(fwdargs[2].arg);
} else if (fwdargs[2].ispath) {
fwd->listen_host = xstrdup(fwdargs[0].arg);
fwd->listen_port = a2port(fwdargs[1].arg);
fwd->connect_path = xstrdup(fwdargs[2].arg);
fwd->connect_port = PORT_STREAMLOCAL;
} else {
fwd->listen_host = NULL;
fwd->listen_port = a2port(fwdargs[0].arg);
fwd->connect_host = xstrdup(fwdargs[1].arg);
fwd->connect_port = a2port(fwdargs[2].arg);
}
break;
case 4:
fwd->listen_host = xstrdup(fwdargs[0].arg);
fwd->listen_port = a2port(fwdargs[1].arg);
fwd->connect_host = xstrdup(fwdargs[2].arg);
fwd->connect_port = a2port(fwdargs[3].arg);
break;
default:
i = 0; /* failure */
}
free(p);
if (dynamicfwd) {
if (!(i == 1 || i == 2))
goto fail_free;
} else {
if (!(i == 3 || i == 4)) {
if (fwd->connect_path == NULL &&
fwd->listen_path == NULL)
goto fail_free;
}
if (fwd->connect_port <= 0 && fwd->connect_path == NULL)
goto fail_free;
}
if ((fwd->listen_port < 0 && fwd->listen_path == NULL) ||
(!remotefwd && fwd->listen_port == 0))
goto fail_free;
if (fwd->connect_host != NULL &&
strlen(fwd->connect_host) >= NI_MAXHOST)
goto fail_free;
/* XXX - if connecting to a remote socket, max sun len may not match this host */
if (fwd->connect_path != NULL &&
strlen(fwd->connect_path) >= PATH_MAX_SUN)
goto fail_free;
if (fwd->listen_host != NULL &&
strlen(fwd->listen_host) >= NI_MAXHOST)
goto fail_free;
if (fwd->listen_path != NULL &&
strlen(fwd->listen_path) >= PATH_MAX_SUN)
goto fail_free;
return (i);
fail_free:
free(fwd->connect_host);
fwd->connect_host = NULL;
free(fwd->connect_path);
fwd->connect_path = NULL;
free(fwd->listen_host);
fwd->listen_host = NULL;
free(fwd->listen_path);
fwd->listen_path = NULL;
return (0);
}
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