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readconf.c
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/* $OpenBSD: readconf.c,v 1.398 2025/03/18 04:53:14 djm Exp $ */
/*
* Author: Tatu Ylonen <[email protected]>
* Copyright (c) 1995 Tatu Ylonen <[email protected]>, 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 <net/if.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>
#ifdef HAVE_IFADDRS_H
# include <ifaddrs.h>
#endif
#include <limits.h>
#include <netdb.h>
#ifdef HAVE_PATHS_H
# include <paths.h>
#endif
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>
#ifdef USE_SYSTEM_GLOB
# include <glob.h>
#else
# include "openbsd-compat/glob.h"
#endif
#ifdef HAVE_UTIL_H
#include <util.h>
#endif
#if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H) && !defined(BROKEN_STRNVIS)
# include <vis.h>
#endif
#include "xmalloc.h"
#include "ssh.h"
#include "ssherr.h"
#include "cipher.h"
#include "pathnames.h"
#include "log.h"
#include "sshkey.h"
#include "misc.h"
#include "readconf.h"
#include "match.h"
#include "kex.h"
#include "mac.h"
#include "uidswap.h"
#include "myproposal.h"
#include "digest.h"
#include "version.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
Ciphers 3des-cbc
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
Ciphers aes128-ctr
PasswordAuthentication no
Host vpn.fake.com
Tunnel yes
TunnelDevice 3
# Defaults for various options
Host *
ForwardAgent no
ForwardX11 no
PasswordAuthentication yes
StrictHostKeyChecking yes
TcpKeepAlive no
IdentityFile ~/.ssh/identity
Port 22
EscapeChar ~
*/
static int read_config_file_depth(const char *filename, struct passwd *pw,
const char *host, const char *original_host, const char *remote_command,
Options *options, int flags, int *activep, int *want_final_pass, int depth);
static int process_config_line_depth(Options *options, struct passwd *pw,
const char *host, const char *original_host, const char *remote_command,
char *line, const char *filename, int linenum, int *activep, int flags,
int *want_final_pass, int depth);
/* Keyword tokens. */
typedef enum {
oBadOption,
oHost, oMatch, oInclude, oTag,
oForwardAgent, oForwardX11, oForwardX11Trusted, oForwardX11Timeout,
oGatewayPorts, oExitOnForwardFailure,
oPasswordAuthentication,
oXAuthLocation,
oIdentityFile, oHostname, oPort, oRemoteForward, oLocalForward,
oPermitRemoteOpen,
oCertificateFile, oAddKeysToAgent, oIdentityAgent,
oUser, oEscapeChar, oProxyCommand,
oGlobalKnownHostsFile, oUserKnownHostsFile, oConnectionAttempts,
oBatchMode, oCheckHostIP, oStrictHostKeyChecking, oCompression,
oTCPKeepAlive, oNumberOfPasswordPrompts,
oLogFacility, oLogLevel, oLogVerbose, oCiphers, oMacs,
oPubkeyAuthentication,
oKbdInteractiveAuthentication, oKbdInteractiveDevices, oHostKeyAlias,
oDynamicForward, oPreferredAuthentications, oHostbasedAuthentication,
oHostKeyAlgorithms, oBindAddress, oBindInterface, oPKCS11Provider,
oClearAllForwardings, oNoHostAuthenticationForLocalhost,
oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout,
oAddressFamily, oGssAuthentication, oGssDelegateCreds,
oServerAliveInterval, oServerAliveCountMax, oIdentitiesOnly,
oSendEnv, oSetEnv, oControlPath, oControlMaster, oControlPersist,
oHashKnownHosts,
oTunnel, oTunnelDevice,
oLocalCommand, oPermitLocalCommand, oRemoteCommand,
oVisualHostKey,
oKexAlgorithms, oIPQoS, oRequestTTY, oSessionType, oStdinNull,
oForkAfterAuthentication, oIgnoreUnknown, oProxyUseFdpass,
oCanonicalDomains, oCanonicalizeHostname, oCanonicalizeMaxDots,
oCanonicalizeFallbackLocal, oCanonicalizePermittedCNAMEs,
oStreamLocalBindMask, oStreamLocalBindUnlink, oRevokedHostKeys,
oFingerprintHash, oUpdateHostkeys, oHostbasedAcceptedAlgorithms,
oPubkeyAcceptedAlgorithms, oCASignatureAlgorithms, oProxyJump,
oSecurityKeyProvider, oKnownHostsCommand, oRequiredRSASize,
oEnableEscapeCommandline, oObscureKeystrokeTiming, oChannelTimeout,
oVersionAddendum,
oIgnore, oIgnoredUnknownOption, oDeprecated, oUnsupported
} OpCodes;
/* Textual representations of the tokens. */
static struct {
const char *name;
OpCodes opcode;
} keywords[] = {
/* Deprecated options */
{ "protocol", oIgnore }, /* NB. silently ignored */
{ "cipher", oDeprecated },
{ "fallbacktorsh", oDeprecated },
{ "globalknownhostsfile2", oDeprecated },
{ "rhostsauthentication", oDeprecated },
{ "userknownhostsfile2", oDeprecated },
{ "useroaming", oDeprecated },
{ "usersh", oDeprecated },
{ "useprivilegedport", oDeprecated },
/* Unsupported options */
{ "afstokenpassing", oUnsupported },
{ "kerberosauthentication", oUnsupported },
{ "kerberostgtpassing", oUnsupported },
{ "rsaauthentication", oUnsupported },
{ "rhostsrsaauthentication", oUnsupported },
{ "compressionlevel", oUnsupported },
/* Sometimes-unsupported options */
#if defined(GSSAPI)
{ "gssapiauthentication", oGssAuthentication },
{ "gssapidelegatecredentials", oGssDelegateCreds },
# else
{ "gssapiauthentication", oUnsupported },
{ "gssapidelegatecredentials", oUnsupported },
#endif
#ifdef ENABLE_PKCS11
{ "pkcs11provider", oPKCS11Provider },
{ "smartcarddevice", oPKCS11Provider },
# else
{ "smartcarddevice", oUnsupported },
{ "pkcs11provider", oUnsupported },
#endif
{ "forwardagent", oForwardAgent },
{ "forwardx11", oForwardX11 },
{ "forwardx11trusted", oForwardX11Trusted },
{ "forwardx11timeout", oForwardX11Timeout },
{ "exitonforwardfailure", oExitOnForwardFailure },
{ "xauthlocation", oXAuthLocation },
{ "gatewayports", oGatewayPorts },
{ "passwordauthentication", oPasswordAuthentication },
{ "kbdinteractiveauthentication", oKbdInteractiveAuthentication },
{ "kbdinteractivedevices", oKbdInteractiveDevices },
{ "challengeresponseauthentication", oKbdInteractiveAuthentication }, /* alias */
{ "skeyauthentication", oKbdInteractiveAuthentication }, /* alias */
{ "tisauthentication", oKbdInteractiveAuthentication }, /* alias */
{ "pubkeyauthentication", oPubkeyAuthentication },
{ "dsaauthentication", oPubkeyAuthentication }, /* alias */
{ "hostbasedauthentication", oHostbasedAuthentication },
{ "identityfile", oIdentityFile },
{ "identityfile2", oIdentityFile }, /* obsolete */
{ "identitiesonly", oIdentitiesOnly },
{ "certificatefile", oCertificateFile },
{ "addkeystoagent", oAddKeysToAgent },
{ "identityagent", oIdentityAgent },
{ "hostname", oHostname },
{ "hostkeyalias", oHostKeyAlias },
{ "proxycommand", oProxyCommand },
{ "port", oPort },
{ "ciphers", oCiphers },
{ "macs", oMacs },
{ "remoteforward", oRemoteForward },
{ "localforward", oLocalForward },
{ "permitremoteopen", oPermitRemoteOpen },
{ "user", oUser },
{ "host", oHost },
{ "match", oMatch },
{ "tag", oTag },
{ "escapechar", oEscapeChar },
{ "globalknownhostsfile", oGlobalKnownHostsFile },
{ "userknownhostsfile", oUserKnownHostsFile },
{ "connectionattempts", oConnectionAttempts },
{ "batchmode", oBatchMode },
{ "checkhostip", oCheckHostIP },
{ "stricthostkeychecking", oStrictHostKeyChecking },
{ "compression", oCompression },
{ "tcpkeepalive", oTCPKeepAlive },
{ "keepalive", oTCPKeepAlive }, /* obsolete */
{ "numberofpasswordprompts", oNumberOfPasswordPrompts },
{ "syslogfacility", oLogFacility },
{ "loglevel", oLogLevel },
{ "logverbose", oLogVerbose },
{ "dynamicforward", oDynamicForward },
{ "preferredauthentications", oPreferredAuthentications },
{ "hostkeyalgorithms", oHostKeyAlgorithms },
{ "casignaturealgorithms", oCASignatureAlgorithms },
{ "bindaddress", oBindAddress },
{ "bindinterface", oBindInterface },
{ "clearallforwardings", oClearAllForwardings },
{ "enablesshkeysign", oEnableSSHKeysign },
{ "verifyhostkeydns", oVerifyHostKeyDNS },
{ "nohostauthenticationforlocalhost", oNoHostAuthenticationForLocalhost },
{ "rekeylimit", oRekeyLimit },
{ "connecttimeout", oConnectTimeout },
{ "addressfamily", oAddressFamily },
{ "serveraliveinterval", oServerAliveInterval },
{ "serveralivecountmax", oServerAliveCountMax },
{ "sendenv", oSendEnv },
{ "setenv", oSetEnv },
{ "controlpath", oControlPath },
{ "controlmaster", oControlMaster },
{ "controlpersist", oControlPersist },
{ "hashknownhosts", oHashKnownHosts },
{ "include", oInclude },
{ "tunnel", oTunnel },
{ "tunneldevice", oTunnelDevice },
{ "localcommand", oLocalCommand },
{ "permitlocalcommand", oPermitLocalCommand },
{ "remotecommand", oRemoteCommand },
{ "visualhostkey", oVisualHostKey },
{ "kexalgorithms", oKexAlgorithms },
{ "ipqos", oIPQoS },
{ "requesttty", oRequestTTY },
{ "sessiontype", oSessionType },
{ "stdinnull", oStdinNull },
{ "forkafterauthentication", oForkAfterAuthentication },
{ "proxyusefdpass", oProxyUseFdpass },
{ "canonicaldomains", oCanonicalDomains },
{ "canonicalizefallbacklocal", oCanonicalizeFallbackLocal },
{ "canonicalizehostname", oCanonicalizeHostname },
{ "canonicalizemaxdots", oCanonicalizeMaxDots },
{ "canonicalizepermittedcnames", oCanonicalizePermittedCNAMEs },
{ "streamlocalbindmask", oStreamLocalBindMask },
{ "streamlocalbindunlink", oStreamLocalBindUnlink },
{ "revokedhostkeys", oRevokedHostKeys },
{ "fingerprinthash", oFingerprintHash },
{ "updatehostkeys", oUpdateHostkeys },
{ "hostbasedacceptedalgorithms", oHostbasedAcceptedAlgorithms },
{ "hostbasedkeytypes", oHostbasedAcceptedAlgorithms }, /* obsolete */
{ "pubkeyacceptedalgorithms", oPubkeyAcceptedAlgorithms },
{ "pubkeyacceptedkeytypes", oPubkeyAcceptedAlgorithms }, /* obsolete */
{ "ignoreunknown", oIgnoreUnknown },
{ "proxyjump", oProxyJump },
{ "securitykeyprovider", oSecurityKeyProvider },
{ "knownhostscommand", oKnownHostsCommand },
{ "requiredrsasize", oRequiredRSASize },
{ "enableescapecommandline", oEnableEscapeCommandline },
{ "obscurekeystroketiming", oObscureKeystrokeTiming },
{ "channeltimeout", oChannelTimeout },
{ "versionaddendum", oVersionAddendum },
{ NULL, oBadOption }
};
static const char *lookup_opcode_name(OpCodes code);
const char *
kex_default_pk_alg(void)
{
static char *pkalgs;
if (pkalgs == NULL) {
char *all_key;
all_key = sshkey_alg_list(0, 0, 1, ',');
pkalgs = match_filter_allowlist(KEX_DEFAULT_PK_ALG, all_key);
free(all_key);
}
return pkalgs;
}
char *
ssh_connection_hash(const char *thishost, const char *host, const char *portstr,
const char *user, const char *jumphost)
{
struct ssh_digest_ctx *md;
u_char conn_hash[SSH_DIGEST_MAX_LENGTH];
if ((md = ssh_digest_start(SSH_DIGEST_SHA1)) == NULL ||
ssh_digest_update(md, thishost, strlen(thishost)) < 0 ||
ssh_digest_update(md, host, strlen(host)) < 0 ||
ssh_digest_update(md, portstr, strlen(portstr)) < 0 ||
ssh_digest_update(md, user, strlen(user)) < 0 ||
ssh_digest_update(md, jumphost, strlen(jumphost)) < 0 ||
ssh_digest_final(md, conn_hash, sizeof(conn_hash)) < 0)
fatal_f("mux digest failed");
ssh_digest_free(md);
return tohex(conn_hash, ssh_digest_bytes(SSH_DIGEST_SHA1));
}
/*
* 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;
int i;
/* Don't add duplicates */
for (i = 0; i < options->num_local_forwards; i++) {
if (forward_equals(newfwd, options->local_forwards + i))
return;
}
options->local_forwards = xreallocarray(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;
int i;
/* Don't add duplicates */
for (i = 0; i < options->num_remote_forwards; i++) {
if (forward_equals(newfwd, options->remote_forwards + i))
return;
}
options->remote_forwards = xreallocarray(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_certificate_file(Options *options, const char *path, int userprovided)
{
int i;
if (options->num_certificate_files >= SSH_MAX_CERTIFICATE_FILES)
fatal("Too many certificate files specified (max %d)",
SSH_MAX_CERTIFICATE_FILES);
/* Avoid registering duplicates */
for (i = 0; i < options->num_certificate_files; i++) {
if (options->certificate_file_userprovided[i] == userprovided &&
strcmp(options->certificate_files[i], path) == 0) {
debug2_f("ignoring duplicate key %s", path);
return;
}
}
options->certificate_file_userprovided[options->num_certificate_files] =
userprovided;
options->certificate_files[options->num_certificate_files++] =
xstrdup(path);
}
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 if (xasprintf(&path, "%s%s", dir, filename) >= PATH_MAX)
fatal("Identity file path %s too long", path);
/* 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_f("ignoring duplicate key %s", 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;
pid_t pid;
int status;
if ((shell = getenv("SHELL")) == NULL)
shell = _PATH_BSHELL;
if (access(shell, X_OK) == -1) {
fatal("Shell \"%s\" is not executable: %s",
shell, strerror(errno));
}
debug("Executing command: '%.500s'", cmd);
/* Fork and execute the command. */
if ((pid = fork()) == 0) {
char *argv[4];
if (stdfd_devnull(1, 1, 0) == -1)
fatal_f("stdfd_devnull failed");
closefrom(STDERR_FILENO + 1);
argv[0] = shell;
argv[1] = "-c";
argv[2] = xstrdup(cmd);
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. */
ssh_signal(SIGTERM, SIG_DFL);
kill(getpid(), SIGTERM);
_exit(1);
}
/* Parent. */
if (pid == -1)
fatal_f("fork: %.100s", strerror(errno));
while (waitpid(pid, &status, 0) == -1) {
if (errno != EINTR && errno != EAGAIN)
fatal_f("waitpid: %s", strerror(errno));
}
if (!WIFEXITED(status)) {
error("command '%.100s' exited abnormally", cmd);
return -1;
}
debug3("command returned status %d", WEXITSTATUS(status));
return WEXITSTATUS(status);
}
/*
* Check whether a local network interface address appears in CIDR pattern-
* list 'addrlist'. Returns 1 if matched or 0 otherwise.
*/
static int
check_match_ifaddrs(const char *addrlist)
{
#ifdef HAVE_IFADDRS_H
struct ifaddrs *ifa, *ifaddrs = NULL;
int r, found = 0;
char addr[NI_MAXHOST];
socklen_t salen;
if (getifaddrs(&ifaddrs) != 0) {
error("match localnetwork: getifaddrs failed: %s",
strerror(errno));
return 0;
}
for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
if (ifa->ifa_addr == NULL || ifa->ifa_name == NULL ||
(ifa->ifa_flags & IFF_UP) == 0)
continue;
switch (ifa->ifa_addr->sa_family) {
case AF_INET:
salen = sizeof(struct sockaddr_in);
break;
case AF_INET6:
salen = sizeof(struct sockaddr_in6);
break;
#ifdef AF_LINK
case AF_LINK:
/* ignore */
continue;
#endif /* AF_LINK */
default:
debug2_f("interface %s: unsupported address family %d",
ifa->ifa_name, ifa->ifa_addr->sa_family);
continue;
}
if ((r = getnameinfo(ifa->ifa_addr, salen, addr, sizeof(addr),
NULL, 0, NI_NUMERICHOST)) != 0) {
debug2_f("interface %s getnameinfo failed: %s",
ifa->ifa_name, gai_strerror(r));
continue;
}
debug3_f("interface %s addr %s", ifa->ifa_name, addr);
if (addr_match_cidr_list(addr, addrlist) == 1) {
debug3_f("matched interface %s: address %s in %s",
ifa->ifa_name, addr, addrlist);
found = 1;
break;
}
}
freeifaddrs(ifaddrs);
return found;
#else /* HAVE_IFADDRS_H */
error("match localnetwork: not supported on this platform");
return 0;
#endif /* HAVE_IFADDRS_H */
}
/*
* Expand a "match exec" command or an Include path, caller must free returned
* value.
*/
static char *
expand_match_exec_or_include_path(const char *path, Options *options,
struct passwd *pw, const char *host_arg, const char *original_host,
int final_pass, int is_include_path)
{
char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV];
char uidstr[32], *conn_hash_hex, *keyalias, *jmphost, *ruser;
char *host, *ret;
int port;
port = options->port <= 0 ? default_ssh_port() : options->port;
ruser = options->user == NULL ? pw->pw_name : options->user;
if (final_pass) {
host = xstrdup(options->hostname);
} else 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);
}
if (gethostname(thishost, sizeof(thishost)) == -1)
fatal("gethostname: %s", strerror(errno));
jmphost = option_clear_or_none(options->jump_host) ?
"" : options->jump_host;
strlcpy(shorthost, thishost, sizeof(shorthost));
shorthost[strcspn(thishost, ".")] = '\0';
snprintf(portstr, sizeof(portstr), "%d", port);
snprintf(uidstr, sizeof(uidstr), "%llu",
(unsigned long long)pw->pw_uid);
conn_hash_hex = ssh_connection_hash(thishost, host,
portstr, ruser, jmphost);
keyalias = options->host_key_alias ? options->host_key_alias : host;
ret = (is_include_path ? percent_dollar_expand : percent_expand)(path,
"C", conn_hash_hex,
"L", shorthost,
"d", pw->pw_dir,
"h", host,
"k", keyalias,
"l", thishost,
"n", original_host,
"p", portstr,
"r", ruser,
"u", pw->pw_name,
"i", uidstr,
"j", jmphost,
(char *)NULL);
free(host);
free(conn_hash_hex);
return ret;
}
/*
* Parse and execute a Match directive.
*/
static int
match_cfg_line(Options *options, const char *full_line, int *acp, char ***avp,
struct passwd *pw, const char *host_arg, const char *original_host,
const char *remote_command, int final_pass, int *want_final_pass,
const char *filename, int linenum)
{
char *arg, *oattrib = NULL, *attrib = NULL, *cmd, *host, *criteria;
const char *ruser;
int r, this_result, result = 1, attributes = 0, negate;
/*
* Configuration is likely to be incomplete at this point so we
* must be prepared to use default values.
*/
ruser = options->user == NULL ? pw->pw_name : options->user;
if (final_pass) {
host = xstrdup(options->hostname);
} else 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);
}
debug2("checking match for '%s' host %s originally %s",
full_line, host, original_host);
while ((attrib = argv_next(acp, avp)) != NULL) {
attrib = oattrib = xstrdup(attrib);
/* Terminate on comment */
if (*attrib == '#') {
argv_consume(acp);
break;
}
arg = criteria = NULL;
this_result = 1;
if ((negate = (attrib[0] == '!')))
attrib++;
/* Criterion "all" has no argument and must appear alone */
if (strcasecmp(attrib, "all") == 0) {
if (attributes > 1 ||
((arg = argv_next(acp, avp)) != NULL &&
*arg != '\0' && *arg != '#')) {
error("%.200s line %d: '%s' cannot be combined "
"with other Match attributes",
filename, linenum, oattrib);
result = -1;
goto out;
}
if (arg != NULL && *arg == '#')
argv_consume(acp); /* consume remaining args */
if (result)
result = negate ? 0 : 1;
goto out;
}
attributes++;
/* criteria "final" and "canonical" have no argument */
if (strcasecmp(attrib, "canonical") == 0 ||
strcasecmp(attrib, "final") == 0) {
/*
* If the config requests "Match final" then remember
* this so we can perform a second pass later.
*/
if (strcasecmp(attrib, "final") == 0 &&
want_final_pass != NULL)
*want_final_pass = 1;
r = !!final_pass; /* force bitmask member to boolean */
if (r == (negate ? 1 : 0))
this_result = result = 0;
debug3("%.200s line %d: %smatched '%s'",
filename, linenum,
this_result ? "" : "not ", oattrib);
continue;
}
/* Keep this list in sync with below */
if (strprefix(attrib, "host=", 1) != NULL ||
strprefix(attrib, "originalhost=", 1) != NULL ||
strprefix(attrib, "user=", 1) != NULL ||
strprefix(attrib, "localuser=", 1) != NULL ||
strprefix(attrib, "localnetwork=", 1) != NULL ||
strprefix(attrib, "version=", 1) != NULL ||
strprefix(attrib, "tagged=", 1) != NULL ||
strprefix(attrib, "command=", 1) != NULL ||
strprefix(attrib, "exec=", 1) != NULL) {
arg = strchr(attrib, '=');
*(arg++) = '\0';
} else if ((arg = argv_next(acp, avp)) == NULL) {
error("%.200s line %d: missing argument for Match '%s'",
filename, linenum, oattrib);
result = -1;
goto out;
}
/*
* All other criteria require an argument, though it may
* be the empty string for the "tagged" and "command"
* options.
*/
if (*arg == '\0' &&
strcasecmp(attrib, "tagged") != 0 &&
strcasecmp(attrib, "command") != 0)
arg = NULL;
if (arg == NULL || *arg == '#') {
error("Missing Match criteria for %s", attrib);
result = -1;
goto out;
}
if (strcasecmp(attrib, "host") == 0) {
criteria = xstrdup(host);
r = match_hostname(host, arg) == 1;
if (r == (negate ? 1 : 0))
this_result = result = 0;
} else if (strcasecmp(attrib, "originalhost") == 0) {
criteria = xstrdup(original_host);
r = match_hostname(original_host, arg) == 1;
if (r == (negate ? 1 : 0))
this_result = result = 0;
} else if (strcasecmp(attrib, "user") == 0) {
criteria = xstrdup(ruser);
r = match_pattern_list(ruser, arg, 0) == 1;
if (r == (negate ? 1 : 0))
this_result = result = 0;
} else if (strcasecmp(attrib, "localuser") == 0) {
criteria = xstrdup(pw->pw_name);
r = match_pattern_list(pw->pw_name, arg, 0) == 1;
if (r == (negate ? 1 : 0))
this_result = result = 0;
} else if (strcasecmp(attrib, "localnetwork") == 0) {
if (addr_match_cidr_list(NULL, arg) == -1) {
/* Error already printed */
result = -1;
goto out;
}
r = check_match_ifaddrs(arg) == 1;
if (r == (negate ? 1 : 0))
this_result = result = 0;
} else if (strcasecmp(attrib, "version") == 0) {
criteria = xstrdup(SSH_RELEASE);
r = match_pattern_list(SSH_RELEASE, arg, 0) == 1;
if (r == (negate ? 1 : 0))
this_result = result = 0;
} else if (strcasecmp(attrib, "tagged") == 0) {
criteria = xstrdup(options->tag == NULL ? "" :
options->tag);
/* Special case: empty criteria matches empty arg */
r = (*criteria == '\0') ? *arg == '\0' :
match_pattern_list(criteria, arg, 0) == 1;
if (r == (negate ? 1 : 0))
this_result = result = 0;
} else if (strcasecmp(attrib, "command") == 0) {
criteria = xstrdup(remote_command == NULL ?
"" : remote_command);
/* Special case: empty criteria matches empty arg */
r = (*criteria == '\0') ? *arg == '\0' :
match_pattern_list(criteria, arg, 0) == 1;
if (r == (negate ? 1 : 0))
this_result = result = 0;
} else if (strcasecmp(attrib, "sessiontype") == 0) {
if (options->session_type == SESSION_TYPE_SUBSYSTEM)
criteria = xstrdup("subsystem");
else if (options->session_type == SESSION_TYPE_NONE)
criteria = xstrdup("none");
else if (remote_command != NULL &&
*remote_command != '\0')
criteria = xstrdup("exec");
else
criteria = xstrdup("shell");
r = match_pattern_list(criteria, arg, 0) == 1;
if (r == (negate ? 1 : 0))
this_result = result = 0;
} else if (strcasecmp(attrib, "exec") == 0) {
if ((cmd = expand_match_exec_or_include_path(arg,
options, pw, host_arg, original_host,
final_pass, 0)) == NULL) {
fatal("%.200s line %d: failed to expand match "
"exec '%.100s'", filename, linenum, arg);
}
if (result != 1) {
/* skip execution if prior predicate failed */
debug3("%.200s line %d: skipped exec "
"\"%.100s\"", filename, linenum, cmd);
free(cmd);
continue;
}
r = execute_in_shell(cmd);
if (r == -1) {
fatal("%.200s line %d: match exec "
"'%.100s' error", filename,
linenum, cmd);
}
criteria = xstrdup(cmd);
free(cmd);
/* Force exit status to boolean */
r = r == 0;
if (r == (negate ? 1 : 0))
this_result = result = 0;
} else {
error("Unsupported Match attribute %s", attrib);
result = -1;
goto out;
}
debug3("%.200s line %d: %smatched '%s%s%.100s%s' ",
filename, linenum, this_result ? "": "not ", oattrib,
criteria == NULL ? "" : " \"",
criteria == NULL ? "" : criteria,
criteria == NULL ? "" : "\"");
free(criteria);
free(oattrib);
oattrib = attrib = NULL;
}
if (attributes == 0) {
error("One or more attributes required for Match");
result = -1;
goto out;
}
out:
if (result != -1)
debug2("match %sfound", result ? "" : "not ");
free(oattrib);
free(host);
return result;
}
/* Remove environment variable by pattern */
static void
rm_env(Options *options, const char *arg, const char *filename, int linenum)
{
u_int i, j, onum_send_env = options->num_send_env;
/* Remove an environment variable */
for (i = 0; i < options->num_send_env; ) {
if (!match_pattern(options->send_env[i], arg + 1)) {
i++;
continue;
}
debug3("%s line %d: removing environment %s",
filename, linenum, options->send_env[i]);
free(options->send_env[i]);
options->send_env[i] = NULL;
for (j = i; j < options->num_send_env - 1; j++) {
options->send_env[j] = options->send_env[j + 1];
options->send_env[j + 1] = NULL;
}
options->num_send_env--;
/* NB. don't increment i */
}
if (onum_send_env != options->num_send_env) {
options->send_env = xrecallocarray(options->send_env,
onum_send_env, options->num_send_env,
sizeof(*options->send_env));
}
}
/*
* 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, 1) == 1)
return oIgnoredUnknownOption;
error("%s: line %d: Bad configuration option: %s",
filename, linenum, cp);
return oBadOption;
}
static void
free_canon_cnames(struct allowed_cname *cnames, u_int n)
{
u_int i;
if (cnames == NULL || n == 0)
return;
for (i = 0; i < n; i++) {
free(cnames[i].source_list);
free(cnames[i].target_list);
}
free(cnames);
}
/* Multistate option parsing */
struct multistate {