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openssh-portable/servconf.c

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/* $OpenBSD: servconf.c,v 1.177 2008/02/10 10:54:28 djm Exp $ */
/*
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
*
* 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/socket.h>
#include <netdb.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
#include <stdarg.h>
#include "xmalloc.h"
#include "ssh.h"
#include "log.h"
#include "buffer.h"
#include "servconf.h"
#include "compat.h"
#include "pathnames.h"
#include "misc.h"
#include "cipher.h"
#include "key.h"
#include "kex.h"
#include "mac.h"
#include "match.h"
#include "channels.h"
#include "groupaccess.h"
static void add_listen_addr(ServerOptions *, char *, u_short);
static void add_one_listen_addr(ServerOptions *, char *, u_short);
/* Use of privilege separation or not */
extern int use_privsep;
extern Buffer cfg;
/* Initializes the server options to their default values. */
void
initialize_server_options(ServerOptions *options)
{
memset(options, 0, sizeof(*options));
/* Portable-specific options */
options->use_pam = -1;
/* Standard Options */
options->num_ports = 0;
options->ports_from_cmdline = 0;
options->listen_addrs = NULL;
options->address_family = -1;
options->num_host_key_files = 0;
options->pid_file = NULL;
options->server_key_bits = -1;
options->login_grace_time = -1;
options->key_regeneration_time = -1;
options->permit_root_login = PERMIT_NOT_SET;
options->ignore_rhosts = -1;
options->ignore_user_known_hosts = -1;
options->print_motd = -1;
options->print_lastlog = -1;
options->x11_forwarding = -1;
options->x11_display_offset = -1;
options->x11_use_localhost = -1;
options->xauth_location = NULL;
options->strict_modes = -1;
options->tcp_keep_alive = -1;
options->log_facility = SYSLOG_FACILITY_NOT_SET;
options->log_level = SYSLOG_LEVEL_NOT_SET;
options->rhosts_rsa_authentication = -1;
options->hostbased_authentication = -1;
options->hostbased_uses_name_from_packet_only = -1;
options->rsa_authentication = -1;
options->pubkey_authentication = -1;
options->kerberos_authentication = -1;
options->kerberos_or_local_passwd = -1;
options->kerberos_ticket_cleanup = -1;
options->kerberos_get_afs_token = -1;
options->gss_authentication=-1;
options->gss_cleanup_creds = -1;
options->password_authentication = -1;
options->kbd_interactive_authentication = -1;
options->challenge_response_authentication = -1;
options->permit_empty_passwd = -1;
options->permit_user_env = -1;
options->use_login = -1;
options->compression = -1;
options->allow_tcp_forwarding = -1;
options->num_allow_users = 0;
options->num_deny_users = 0;
options->num_allow_groups = 0;
options->num_deny_groups = 0;
options->ciphers = NULL;
options->macs = NULL;
options->protocol = SSH_PROTO_UNKNOWN;
options->gateway_ports = -1;
options->num_subsystems = 0;
options->max_startups_begin = -1;
options->max_startups_rate = -1;
options->max_startups = -1;
options->max_authtries = -1;
options->banner = NULL;
options->use_dns = -1;
options->client_alive_interval = -1;
options->client_alive_count_max = -1;
options->authorized_keys_file = NULL;
options->authorized_keys_file2 = NULL;
options->num_accept_env = 0;
options->permit_tun = -1;
options->num_permitted_opens = -1;
options->adm_forced_command = NULL;
options->chroot_directory = NULL;
}
void
fill_default_server_options(ServerOptions *options)
{
/* Portable-specific options */
if (options->use_pam == -1)
options->use_pam = 0;
/* Standard Options */
if (options->protocol == SSH_PROTO_UNKNOWN)
options->protocol = SSH_PROTO_1|SSH_PROTO_2;
if (options->num_host_key_files == 0) {
/* fill default hostkeys for protocols */
if (options->protocol & SSH_PROTO_1)
options->host_key_files[options->num_host_key_files++] =
_PATH_HOST_KEY_FILE;
if (options->protocol & SSH_PROTO_2) {
options->host_key_files[options->num_host_key_files++] =
_PATH_HOST_RSA_KEY_FILE;
options->host_key_files[options->num_host_key_files++] =
_PATH_HOST_DSA_KEY_FILE;
}
}
if (options->num_ports == 0)
options->ports[options->num_ports++] = SSH_DEFAULT_PORT;
if (options->listen_addrs == NULL)
add_listen_addr(options, NULL, 0);
if (options->pid_file == NULL)
options->pid_file = _PATH_SSH_DAEMON_PID_FILE;
if (options->server_key_bits == -1)
options->server_key_bits = 768;
if (options->login_grace_time == -1)
options->login_grace_time = 120;
if (options->key_regeneration_time == -1)
options->key_regeneration_time = 3600;
if (options->permit_root_login == PERMIT_NOT_SET)
options->permit_root_login = PERMIT_YES;
if (options->ignore_rhosts == -1)
options->ignore_rhosts = 1;
if (options->ignore_user_known_hosts == -1)
options->ignore_user_known_hosts = 0;
if (options->print_motd == -1)
options->print_motd = 1;
if (options->print_lastlog == -1)
options->print_lastlog = 1;
if (options->x11_forwarding == -1)
options->x11_forwarding = 0;
if (options->x11_display_offset == -1)
options->x11_display_offset = 10;
if (options->x11_use_localhost == -1)
options->x11_use_localhost = 1;
if (options->xauth_location == NULL)
options->xauth_location = _PATH_XAUTH;
if (options->strict_modes == -1)
options->strict_modes = 1;
if (options->tcp_keep_alive == -1)
options->tcp_keep_alive = 1;
if (options->log_facility == SYSLOG_FACILITY_NOT_SET)
options->log_facility = SYSLOG_FACILITY_AUTH;
if (options->log_level == SYSLOG_LEVEL_NOT_SET)
options->log_level = SYSLOG_LEVEL_INFO;
if (options->rhosts_rsa_authentication == -1)
options->rhosts_rsa_authentication = 0;
if (options->hostbased_authentication == -1)
options->hostbased_authentication = 0;
if (options->hostbased_uses_name_from_packet_only == -1)
options->hostbased_uses_name_from_packet_only = 0;
if (options->rsa_authentication == -1)
options->rsa_authentication = 1;
if (options->pubkey_authentication == -1)
options->pubkey_authentication = 1;
if (options->kerberos_authentication == -1)
options->kerberos_authentication = 0;
if (options->kerberos_or_local_passwd == -1)
options->kerberos_or_local_passwd = 1;
if (options->kerberos_ticket_cleanup == -1)
options->kerberos_ticket_cleanup = 1;
if (options->kerberos_get_afs_token == -1)
options->kerberos_get_afs_token = 0;
if (options->gss_authentication == -1)
options->gss_authentication = 0;
if (options->gss_cleanup_creds == -1)
options->gss_cleanup_creds = 1;
if (options->password_authentication == -1)
options->password_authentication = 1;
if (options->kbd_interactive_authentication == -1)
options->kbd_interactive_authentication = 0;
if (options->challenge_response_authentication == -1)
options->challenge_response_authentication = 1;
if (options->permit_empty_passwd == -1)
options->permit_empty_passwd = 0;
if (options->permit_user_env == -1)
options->permit_user_env = 0;
if (options->use_login == -1)
options->use_login = 0;
if (options->compression == -1)
options->compression = COMP_DELAYED;
if (options->allow_tcp_forwarding == -1)
options->allow_tcp_forwarding = 1;
if (options->gateway_ports == -1)
options->gateway_ports = 0;
if (options->max_startups == -1)
options->max_startups = 10;
if (options->max_startups_rate == -1)
options->max_startups_rate = 100; /* 100% */
if (options->max_startups_begin == -1)
options->max_startups_begin = options->max_startups;
if (options->max_authtries == -1)
options->max_authtries = DEFAULT_AUTH_FAIL_MAX;
if (options->use_dns == -1)
options->use_dns = 1;
if (options->client_alive_interval == -1)
options->client_alive_interval = 0;
if (options->client_alive_count_max == -1)
options->client_alive_count_max = 3;
if (options->authorized_keys_file2 == NULL) {
/* authorized_keys_file2 falls back to authorized_keys_file */
if (options->authorized_keys_file != NULL)
options->authorized_keys_file2 = options->authorized_keys_file;
else
options->authorized_keys_file2 = _PATH_SSH_USER_PERMITTED_KEYS2;
}
if (options->authorized_keys_file == NULL)
options->authorized_keys_file = _PATH_SSH_USER_PERMITTED_KEYS;
if (options->permit_tun == -1)
options->permit_tun = SSH_TUNMODE_NO;
/* Turn privilege separation on by default */
if (use_privsep == -1)
use_privsep = 1;
#ifndef HAVE_MMAP
if (use_privsep && options->compression == 1) {
error("This platform does not support both privilege "
"separation and compression");
error("Compression disabled");
options->compression = 0;
}
#endif
}
/* Keyword tokens. */
typedef enum {
sBadOption, /* == unknown option */
/* Portable-specific options */
sUsePAM,
/* Standard Options */
sPort, sHostKeyFile, sServerKeyBits, sLoginGraceTime, sKeyRegenerationTime,
sPermitRootLogin, sLogFacility, sLogLevel,
sRhostsRSAAuthentication, sRSAAuthentication,
sKerberosAuthentication, sKerberosOrLocalPasswd, sKerberosTicketCleanup,
sKerberosGetAFSToken,
sKerberosTgtPassing, sChallengeResponseAuthentication,
sPasswordAuthentication, sKbdInteractiveAuthentication,
sListenAddress, sAddressFamily,
sPrintMotd, sPrintLastLog, sIgnoreRhosts,
sX11Forwarding, sX11DisplayOffset, sX11UseLocalhost,
sStrictModes, sEmptyPasswd, sTCPKeepAlive,
sPermitUserEnvironment, sUseLogin, sAllowTcpForwarding, sCompression,
sAllowUsers, sDenyUsers, sAllowGroups, sDenyGroups,
sIgnoreUserKnownHosts, sCiphers, sMacs, sProtocol, sPidFile,
sGatewayPorts, sPubkeyAuthentication, sXAuthLocation, sSubsystem,
sMaxStartups, sMaxAuthTries,
sBanner, sUseDNS, sHostbasedAuthentication,
sHostbasedUsesNameFromPacketOnly, sClientAliveInterval,
sClientAliveCountMax, sAuthorizedKeysFile, sAuthorizedKeysFile2,
sGssAuthentication, sGssCleanupCreds, sAcceptEnv, sPermitTunnel,
sMatch, sPermitOpen, sForceCommand, sChrootDirectory,
sUsePrivilegeSeparation,
sDeprecated, sUnsupported
} ServerOpCodes;
#define SSHCFG_GLOBAL 0x01 /* allowed in main section of sshd_config */
#define SSHCFG_MATCH 0x02 /* allowed inside a Match section */
#define SSHCFG_ALL (SSHCFG_GLOBAL|SSHCFG_MATCH)
/* Textual representation of the tokens. */
static struct {
const char *name;
ServerOpCodes opcode;
u_int flags;
} keywords[] = {
/* Portable-specific options */
#ifdef USE_PAM
{ "usepam", sUsePAM, SSHCFG_GLOBAL },
#else
{ "usepam", sUnsupported, SSHCFG_GLOBAL },
#endif
{ "pamauthenticationviakbdint", sDeprecated, SSHCFG_GLOBAL },
/* Standard Options */
{ "port", sPort, SSHCFG_GLOBAL },
{ "hostkey", sHostKeyFile, SSHCFG_GLOBAL },
{ "hostdsakey", sHostKeyFile, SSHCFG_GLOBAL }, /* alias */
{ "pidfile", sPidFile, SSHCFG_GLOBAL },
{ "serverkeybits", sServerKeyBits, SSHCFG_GLOBAL },
{ "logingracetime", sLoginGraceTime, SSHCFG_GLOBAL },
{ "keyregenerationinterval", sKeyRegenerationTime, SSHCFG_GLOBAL },
{ "permitrootlogin", sPermitRootLogin, SSHCFG_ALL },
{ "syslogfacility", sLogFacility, SSHCFG_GLOBAL },
{ "loglevel", sLogLevel, SSHCFG_GLOBAL },
{ "rhostsauthentication", sDeprecated, SSHCFG_GLOBAL },
{ "rhostsrsaauthentication", sRhostsRSAAuthentication, SSHCFG_ALL },
{ "hostbasedauthentication", sHostbasedAuthentication, SSHCFG_ALL },
{ "hostbasedusesnamefrompacketonly", sHostbasedUsesNameFromPacketOnly, SSHCFG_GLOBAL },
{ "rsaauthentication", sRSAAuthentication, SSHCFG_ALL },
{ "pubkeyauthentication", sPubkeyAuthentication, SSHCFG_ALL },
{ "dsaauthentication", sPubkeyAuthentication, SSHCFG_GLOBAL }, /* alias */
#ifdef KRB5
{ "kerberosauthentication", sKerberosAuthentication, SSHCFG_ALL },
{ "kerberosorlocalpasswd", sKerberosOrLocalPasswd, SSHCFG_GLOBAL },
{ "kerberosticketcleanup", sKerberosTicketCleanup, SSHCFG_GLOBAL },
#ifdef USE_AFS
{ "kerberosgetafstoken", sKerberosGetAFSToken, SSHCFG_GLOBAL },
#else
{ "kerberosgetafstoken", sUnsupported, SSHCFG_GLOBAL },
#endif
#else
{ "kerberosauthentication", sUnsupported, SSHCFG_ALL },
{ "kerberosorlocalpasswd", sUnsupported, SSHCFG_GLOBAL },
{ "kerberosticketcleanup", sUnsupported, SSHCFG_GLOBAL },
{ "kerberosgetafstoken", sUnsupported, SSHCFG_GLOBAL },
#endif
{ "kerberostgtpassing", sUnsupported, SSHCFG_GLOBAL },
{ "afstokenpassing", sUnsupported, SSHCFG_GLOBAL },
#ifdef GSSAPI
{ "gssapiauthentication", sGssAuthentication, SSHCFG_ALL },
{ "gssapicleanupcredentials", sGssCleanupCreds, SSHCFG_GLOBAL },
#else
{ "gssapiauthentication", sUnsupported, SSHCFG_ALL },
{ "gssapicleanupcredentials", sUnsupported, SSHCFG_GLOBAL },
#endif
{ "passwordauthentication", sPasswordAuthentication, SSHCFG_ALL },
{ "kbdinteractiveauthentication", sKbdInteractiveAuthentication, SSHCFG_ALL },
{ "challengeresponseauthentication", sChallengeResponseAuthentication, SSHCFG_GLOBAL },
{ "skeyauthentication", sChallengeResponseAuthentication, SSHCFG_GLOBAL }, /* alias */
{ "checkmail", sDeprecated, SSHCFG_GLOBAL },
{ "listenaddress", sListenAddress, SSHCFG_GLOBAL },
{ "addressfamily", sAddressFamily, SSHCFG_GLOBAL },
{ "printmotd", sPrintMotd, SSHCFG_GLOBAL },
{ "printlastlog", sPrintLastLog, SSHCFG_GLOBAL },
{ "ignorerhosts", sIgnoreRhosts, SSHCFG_GLOBAL },
{ "ignoreuserknownhosts", sIgnoreUserKnownHosts, SSHCFG_GLOBAL },
{ "x11forwarding", sX11Forwarding, SSHCFG_ALL },
{ "x11displayoffset", sX11DisplayOffset, SSHCFG_ALL },
{ "x11uselocalhost", sX11UseLocalhost, SSHCFG_ALL },
{ "xauthlocation", sXAuthLocation, SSHCFG_GLOBAL },
{ "strictmodes", sStrictModes, SSHCFG_GLOBAL },
{ "permitemptypasswords", sEmptyPasswd, SSHCFG_GLOBAL },
{ "permituserenvironment", sPermitUserEnvironment, SSHCFG_GLOBAL },
{ "uselogin", sUseLogin, SSHCFG_GLOBAL },
{ "compression", sCompression, SSHCFG_GLOBAL },
{ "tcpkeepalive", sTCPKeepAlive, SSHCFG_GLOBAL },
{ "keepalive", sTCPKeepAlive, SSHCFG_GLOBAL }, /* obsolete alias */
{ "allowtcpforwarding", sAllowTcpForwarding, SSHCFG_ALL },
{ "allowusers", sAllowUsers, SSHCFG_GLOBAL },
{ "denyusers", sDenyUsers, SSHCFG_GLOBAL },
{ "allowgroups", sAllowGroups, SSHCFG_GLOBAL },
{ "denygroups", sDenyGroups, SSHCFG_GLOBAL },
{ "ciphers", sCiphers, SSHCFG_GLOBAL },
{ "macs", sMacs, SSHCFG_GLOBAL },
{ "protocol", sProtocol, SSHCFG_GLOBAL },
{ "gatewayports", sGatewayPorts, SSHCFG_ALL },
{ "subsystem", sSubsystem, SSHCFG_GLOBAL },
{ "maxstartups", sMaxStartups, SSHCFG_GLOBAL },
{ "maxauthtries", sMaxAuthTries, SSHCFG_GLOBAL },
{ "banner", sBanner, SSHCFG_ALL },
{ "usedns", sUseDNS, SSHCFG_GLOBAL },
{ "verifyreversemapping", sDeprecated, SSHCFG_GLOBAL },
{ "reversemappingcheck", sDeprecated, SSHCFG_GLOBAL },
{ "clientaliveinterval", sClientAliveInterval, SSHCFG_GLOBAL },
{ "clientalivecountmax", sClientAliveCountMax, SSHCFG_GLOBAL },
{ "authorizedkeysfile", sAuthorizedKeysFile, SSHCFG_GLOBAL },
{ "authorizedkeysfile2", sAuthorizedKeysFile2, SSHCFG_GLOBAL },
{ "useprivilegeseparation", sUsePrivilegeSeparation, SSHCFG_GLOBAL },
{ "acceptenv", sAcceptEnv, SSHCFG_GLOBAL },
{ "permittunnel", sPermitTunnel, SSHCFG_GLOBAL },
{ "match", sMatch, SSHCFG_ALL },
{ "permitopen", sPermitOpen, SSHCFG_ALL },
{ "forcecommand", sForceCommand, SSHCFG_ALL },
{ "chrootdirectory", sChrootDirectory, SSHCFG_ALL },
{ NULL, sBadOption, 0 }
};
/*
* Returns the number of the token pointed to by cp or sBadOption.
*/
static ServerOpCodes
parse_token(const char *cp, const char *filename,
int linenum, u_int *flags)
{
u_int i;
for (i = 0; keywords[i].name; i++)
if (strcasecmp(cp, keywords[i].name) == 0) {
*flags = keywords[i].flags;
return keywords[i].opcode;
}
error("%s: line %d: Bad configuration option: %s",
filename, linenum, cp);
return sBadOption;
}
static void
add_listen_addr(ServerOptions *options, char *addr, u_short port)
{
u_int i;
if (options->num_ports == 0)
options->ports[options->num_ports++] = SSH_DEFAULT_PORT;
if (options->address_family == -1)
options->address_family = AF_UNSPEC;
if (port == 0)
for (i = 0; i < options->num_ports; i++)
add_one_listen_addr(options, addr, options->ports[i]);
else
add_one_listen_addr(options, addr, port);
}
static void
add_one_listen_addr(ServerOptions *options, char *addr, u_short port)
{
struct addrinfo hints, *ai, *aitop;
char strport[NI_MAXSERV];
int gaierr;
memset(&hints, 0, sizeof(hints));
hints.ai_family = options->address_family;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = (addr == NULL) ? AI_PASSIVE : 0;
snprintf(strport, sizeof strport, "%u", port);
if ((gaierr = getaddrinfo(addr, strport, &hints, &aitop)) != 0)
fatal("bad addr or host: %s (%s)",
addr ? addr : "<NULL>",
ssh_gai_strerror(gaierr));
for (ai = aitop; ai->ai_next; ai = ai->ai_next)
;
ai->ai_next = options->listen_addrs;
options->listen_addrs = aitop;
}
/*
* The strategy for the Match blocks is that the config file is parsed twice.
*
* The first time is at startup. activep is initialized to 1 and the
* directives in the global context are processed and acted on. Hitting a
* Match directive unsets activep and the directives inside the block are
* checked for syntax only.
*
* The second time is after a connection has been established but before
* authentication. activep is initialized to 2 and global config directives
* are ignored since they have already been processed. If the criteria in a
* Match block is met, activep is set and the subsequent directives
* processed and actioned until EOF or another Match block unsets it. Any
* options set are copied into the main server config.
*
* Potential additions/improvements:
* - Add Match support for pre-kex directives, eg Protocol, Ciphers.
*
* - Add a Tag directive (idea from David Leonard) ala pf, eg:
* Match Address 192.168.0.*
* Tag trusted
* Match Group wheel
* Tag trusted
* Match Tag trusted
* AllowTcpForwarding yes
* GatewayPorts clientspecified
* [...]
*
* - Add a PermittedChannelRequests directive
* Match Group shell
* PermittedChannelRequests session,forwarded-tcpip
*/
static int
match_cfg_line_group(const char *grps, int line, const char *user)
{
int result = 0;
u_int ngrps = 0;
char *arg, *p, *cp, *grplist[MAX_MATCH_GROUPS];
struct passwd *pw;
/*
* Even if we do not have a user yet, we still need to check for
* valid syntax.
*/
arg = cp = xstrdup(grps);
while ((p = strsep(&cp, ",")) != NULL && *p != '\0') {
if (ngrps >= MAX_MATCH_GROUPS) {
error("line %d: too many groups in Match Group", line);
result = -1;
goto out;
}
grplist[ngrps++] = p;
}
if (user == NULL)
goto out;
if ((pw = getpwnam(user)) == NULL) {
debug("Can't match group at line %d because user %.100s does "
"not exist", line, user);
} else if (ga_init(pw->pw_name, pw->pw_gid) == 0) {
debug("Can't Match group because user %.100s not in any group "
"at line %d", user, line);
} else if (ga_match(grplist, ngrps) != 1) {
debug("user %.100s does not match group %.100s at line %d",
user, arg, line);
} else {
debug("user %.100s matched group %.100s at line %d", user,
arg, line);
result = 1;
}
out:
ga_free();
xfree(arg);
return result;
}
static int
match_cfg_line(char **condition, int line, const char *user, const char *host,
const char *address)
{
int result = 1;
char *arg, *attrib, *cp = *condition;
size_t len;
if (user == NULL)
debug3("checking syntax for 'Match %s'", cp);
else
debug3("checking match for '%s' user %s host %s addr %s", cp,
user ? user : "(null)", host ? host : "(null)",
address ? address : "(null)");
while ((attrib = strdelim(&cp)) && *attrib != '\0') {
if ((arg = strdelim(&cp)) == NULL || *arg == '\0') {
error("Missing Match criteria for %s", attrib);
return -1;
}
len = strlen(arg);
if (strcasecmp(attrib, "user") == 0) {
if (!user) {
result = 0;
continue;
}
if (match_pattern_list(user, arg, len, 0) != 1)
result = 0;
else
debug("user %.100s matched 'User %.100s' at "
"line %d", user, arg, line);
} else if (strcasecmp(attrib, "group") == 0) {
switch (match_cfg_line_group(arg, line, user)) {
case -1:
return -1;
case 0:
result = 0;
}
} else if (strcasecmp(attrib, "host") == 0) {
if (!host) {
result = 0;
continue;
}
if (match_hostname(host, arg, len) != 1)
result = 0;
else
debug("connection from %.100s matched 'Host "
"%.100s' at line %d", host, arg, line);
} else if (strcasecmp(attrib, "address") == 0) {
if (!address) {
result = 0;
continue;
}
if (match_hostname(address, arg, len) != 1)
result = 0;
else
debug("connection from %.100s matched 'Address "
"%.100s' at line %d", address, arg, line);
} else {
error("Unsupported Match attribute %s", attrib);
return -1;
}
}
if (user != NULL)
debug3("match %sfound", result ? "" : "not ");
*condition = cp;
return result;
}
#define WHITESPACE " \t\r\n"
int
process_server_config_line(ServerOptions *options, char *line,
const char *filename, int linenum, int *activep, const char *user,
const char *host, const char *address)
{
char *cp, **charptr, *arg, *p;
int cmdline = 0, *intptr, value, n;
SyslogFacility *log_facility_ptr;
LogLevel *log_level_ptr;
ServerOpCodes opcode;
u_short port;
u_int i, flags = 0;
size_t len;
cp = line;
if ((arg = strdelim(&cp)) == NULL)
return 0;
/* Ignore leading whitespace */
if (*arg == '\0')
arg = strdelim(&cp);
if (!arg || !*arg || *arg == '#')
return 0;
intptr = NULL;
charptr = NULL;
opcode = parse_token(arg, filename, linenum, &flags);
if (activep == NULL) { /* We are processing a command line directive */
cmdline = 1;
activep = &cmdline;
}
if (*activep && opcode != sMatch)
debug3("%s:%d setting %s %s", filename, linenum, arg, cp);
if (*activep == 0 && !(flags & SSHCFG_MATCH)) {
if (user == NULL) {
fatal("%s line %d: Directive '%s' is not allowed "
"within a Match block", filename, linenum, arg);
} else { /* this is a directive we have already processed */
while (arg)
arg = strdelim(&cp);
return 0;
}
}
switch (opcode) {
/* Portable-specific options */
case sUsePAM:
intptr = &options->use_pam;
goto parse_flag;
/* Standard Options */
case sBadOption:
return -1;
case sPort:
/* ignore ports from configfile if cmdline specifies ports */
if (options->ports_from_cmdline)
return 0;
if (options->listen_addrs != NULL)
fatal("%s line %d: ports must be specified before "
"ListenAddress.", filename, linenum);
if (options->num_ports >= MAX_PORTS)
fatal("%s line %d: too many ports.",
filename, linenum);
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing port number.",
filename, linenum);
options->ports[options->num_ports++] = a2port(arg);
if (options->ports[options->num_ports-1] == 0)
fatal("%s line %d: Badly formatted port number.",
filename, linenum);
break;
case sServerKeyBits:
intptr = &options->server_key_bits;
parse_int:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing integer value.",
filename, linenum);
value = atoi(arg);
if (*activep && *intptr == -1)
*intptr = value;
break;
case sLoginGraceTime:
intptr = &options->login_grace_time;
parse_time:
arg = strdelim(&cp);
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 (*intptr == -1)
*intptr = value;
break;
case sKeyRegenerationTime:
intptr = &options->key_regeneration_time;
goto parse_time;
case sListenAddress:
arg = strdelim(&cp);
if (arg == NULL || *arg == '\0')
fatal("%s line %d: missing address",
filename, linenum);
/* check for bare IPv6 address: no "[]" and 2 or more ":" */
if (strchr(arg, '[') == NULL && (p = strchr(arg, ':')) != NULL
&& strchr(p+1, ':') != NULL) {
add_listen_addr(options, arg, 0);
break;
}
p = hpdelim(&arg);
if (p == NULL)
fatal("%s line %d: bad address:port usage",
filename, linenum);
p = cleanhostname(p);
if (arg == NULL)
port = 0;
else if ((port = a2port(arg)) == 0)
fatal("%s line %d: bad port number", filename, linenum);
add_listen_addr(options, p, port);
break;
case sAddressFamily:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing address family.",
filename, linenum);
intptr = &options->address_family;
if (options->listen_addrs != NULL)
fatal("%s line %d: address family must be specified before "
"ListenAddress.", filename, linenum);
if (strcasecmp(arg, "inet") == 0)
value = AF_INET;
else if (strcasecmp(arg, "inet6") == 0)
value = AF_INET6;
else if (strcasecmp(arg, "any") == 0)
value = AF_UNSPEC;
else
fatal("%s line %d: unsupported address family \"%s\".",
filename, linenum, arg);
if (*intptr == -1)
*intptr = value;
break;
case sHostKeyFile:
intptr = &options->num_host_key_files;
if (*intptr >= MAX_HOSTKEYS)
fatal("%s line %d: too many host keys specified (max %d).",
filename, linenum, MAX_HOSTKEYS);
charptr = &options->host_key_files[*intptr];
parse_filename:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing file name.",
filename, linenum);
if (*activep && *charptr == NULL) {
*charptr = tilde_expand_filename(arg, getuid());
/* increase optional counter */
if (intptr != NULL)
*intptr = *intptr + 1;
}
break;
case sPidFile:
charptr = &options->pid_file;
goto parse_filename;
case sPermitRootLogin:
intptr = &options->permit_root_login;
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing yes/"
"without-password/forced-commands-only/no "
"argument.", filename, linenum);
value = 0; /* silence compiler */
if (strcmp(arg, "without-password") == 0)
value = PERMIT_NO_PASSWD;
else if (strcmp(arg, "forced-commands-only") == 0)
value = PERMIT_FORCED_ONLY;
else if (strcmp(arg, "yes") == 0)
value = PERMIT_YES;
else if (strcmp(arg, "no") == 0)
value = PERMIT_NO;
else
fatal("%s line %d: Bad yes/"
"without-password/forced-commands-only/no "
"argument: %s", filename, linenum, arg);
if (*activep && *intptr == -1)
*intptr = value;
break;
case sIgnoreRhosts:
intptr = &options->ignore_rhosts;
parse_flag:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing yes/no argument.",
filename, linenum);
value = 0; /* silence compiler */
if (strcmp(arg, "yes") == 0)
value = 1;
else if (strcmp(arg, "no") == 0)
value = 0;
else
fatal("%s line %d: Bad yes/no argument: %s",
filename, linenum, arg);
if (*activep && *intptr == -1)
*intptr = value;
break;
case sIgnoreUserKnownHosts:
intptr = &options->ignore_user_known_hosts;
goto parse_flag;
case sRhostsRSAAuthentication:
intptr = &options->rhosts_rsa_authentication;
goto parse_flag;
case sHostbasedAuthentication:
intptr = &options->hostbased_authentication;
goto parse_flag;
case sHostbasedUsesNameFromPacketOnly:
intptr = &options->hostbased_uses_name_from_packet_only;
goto parse_flag;
case sRSAAuthentication:
intptr = &options->rsa_authentication;
goto parse_flag;
case sPubkeyAuthentication:
intptr = &options->pubkey_authentication;
goto parse_flag;
case sKerberosAuthentication:
intptr = &options->kerberos_authentication;
goto parse_flag;
case sKerberosOrLocalPasswd:
intptr = &options->kerberos_or_local_passwd;
goto parse_flag;
case sKerberosTicketCleanup:
intptr = &options->kerberos_ticket_cleanup;
goto parse_flag;
case sKerberosGetAFSToken:
intptr = &options->kerberos_get_afs_token;
goto parse_flag;
case sGssAuthentication:
intptr = &options->gss_authentication;
goto parse_flag;
case sGssCleanupCreds:
intptr = &options->gss_cleanup_creds;
goto parse_flag;
case sPasswordAuthentication:
intptr = &options->password_authentication;
goto parse_flag;
case sKbdInteractiveAuthentication:
intptr = &options->kbd_interactive_authentication;
goto parse_flag;
case sChallengeResponseAuthentication:
intptr = &options->challenge_response_authentication;
goto parse_flag;
case sPrintMotd:
intptr = &options->print_motd;
goto parse_flag;
case sPrintLastLog:
intptr = &options->print_lastlog;
goto parse_flag;
case sX11Forwarding:
intptr = &options->x11_forwarding;
goto parse_flag;
case sX11DisplayOffset:
intptr = &options->x11_display_offset;
goto parse_int;
case sX11UseLocalhost:
intptr = &options->x11_use_localhost;
goto parse_flag;
case sXAuthLocation:
charptr = &options->xauth_location;
goto parse_filename;
case sStrictModes:
intptr = &options->strict_modes;
goto parse_flag;
case sTCPKeepAlive:
intptr = &options->tcp_keep_alive;
goto parse_flag;
case sEmptyPasswd:
intptr = &options->permit_empty_passwd;
goto parse_flag;
case sPermitUserEnvironment:
intptr = &options->permit_user_env;
goto parse_flag;
case sUseLogin:
intptr = &options->use_login;
goto parse_flag;
case sCompression:
intptr = &options->compression;
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing yes/no/delayed "
"argument.", filename, linenum);
value = 0; /* silence compiler */
if (strcmp(arg, "delayed") == 0)
value = COMP_DELAYED;
else if (strcmp(arg, "yes") == 0)
value = COMP_ZLIB;
else if (strcmp(arg, "no") == 0)
value = COMP_NONE;
else
fatal("%s line %d: Bad yes/no/delayed "
"argument: %s", filename, linenum, arg);
if (*intptr == -1)
*intptr = value;
break;
case sGatewayPorts:
intptr = &options->gateway_ports;
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing yes/no/clientspecified "
"argument.", filename, linenum);
value = 0; /* silence compiler */
if (strcmp(arg, "clientspecified") == 0)
value = 2;
else if (strcmp(arg, "yes") == 0)
value = 1;
else if (strcmp(arg, "no") == 0)
value = 0;
else
fatal("%s line %d: Bad yes/no/clientspecified "
"argument: %s", filename, linenum, arg);
if (*activep && *intptr == -1)
*intptr = value;
break;
case sUseDNS:
intptr = &options->use_dns;
goto parse_flag;
case sLogFacility:
log_facility_ptr = &options->log_facility;
arg = strdelim(&cp);
value = log_facility_number(arg);
if (value == SYSLOG_FACILITY_NOT_SET)
fatal("%.200s line %d: unsupported log facility '%s'",
filename, linenum, arg ? arg : "<NONE>");
if (*log_facility_ptr == -1)
*log_facility_ptr = (SyslogFacility) value;
break;
case sLogLevel:
log_level_ptr = &options->log_level;
arg = strdelim(&cp);
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 (*log_level_ptr == -1)
*log_level_ptr = (LogLevel) value;
break;
case sAllowTcpForwarding:
intptr = &options->allow_tcp_forwarding;
goto parse_flag;
case sUsePrivilegeSeparation:
intptr = &use_privsep;
goto parse_flag;
case sAllowUsers:
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (options->num_allow_users >= MAX_ALLOW_USERS)
fatal("%s line %d: too many allow users.",
filename, linenum);
options->allow_users[options->num_allow_users++] =
xstrdup(arg);
}
break;
case sDenyUsers:
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (options->num_deny_users >= MAX_DENY_USERS)
fatal("%s line %d: too many deny users.",
filename, linenum);
options->deny_users[options->num_deny_users++] =
xstrdup(arg);
}
break;
case sAllowGroups:
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (options->num_allow_groups >= MAX_ALLOW_GROUPS)
fatal("%s line %d: too many allow groups.",
filename, linenum);
options->allow_groups[options->num_allow_groups++] =
xstrdup(arg);
}
break;
case sDenyGroups:
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (options->num_deny_groups >= MAX_DENY_GROUPS)
fatal("%s line %d: too many deny groups.",
filename, linenum);
options->deny_groups[options->num_deny_groups++] = xstrdup(arg);
}
break;
case sCiphers:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing argument.", filename, linenum);
if (!ciphers_valid(arg))
fatal("%s line %d: Bad SSH2 cipher spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (options->ciphers == NULL)
options->ciphers = xstrdup(arg);
break;
case sMacs:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing argument.", filename, linenum);
if (!mac_valid(arg))
fatal("%s line %d: Bad SSH2 mac spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (options->macs == NULL)
options->macs = xstrdup(arg);
break;
case sProtocol:
intptr = &options->protocol;
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing argument.", filename, linenum);
value = proto_spec(arg);
if (value == SSH_PROTO_UNKNOWN)
fatal("%s line %d: Bad protocol spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*intptr == SSH_PROTO_UNKNOWN)
*intptr = value;
break;
case sSubsystem:
if (options->num_subsystems >= MAX_SUBSYSTEMS) {
fatal("%s line %d: too many subsystems defined.",
filename, linenum);
}
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing subsystem name.",
filename, linenum);
if (!*activep) {
arg = strdelim(&cp);
break;
}
for (i = 0; i < options->num_subsystems; i++)
if (strcmp(arg, options->subsystem_name[i]) == 0)
fatal("%s line %d: Subsystem '%s' already defined.",
filename, linenum, arg);
options->subsystem_name[options->num_subsystems] = xstrdup(arg);
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing subsystem command.",
filename, linenum);
options->subsystem_command[options->num_subsystems] = xstrdup(arg);
/* Collect arguments (separate to executable) */
p = xstrdup(arg);
len = strlen(p) + 1;
while ((arg = strdelim(&cp)) != NULL && *arg != '\0') {
len += 1 + strlen(arg);
p = xrealloc(p, 1, len);
strlcat(p, " ", len);
strlcat(p, arg, len);
}
options->subsystem_args[options->num_subsystems] = p;
options->num_subsystems++;
break;
case sMaxStartups:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing MaxStartups spec.",
filename, linenum);
if ((n = sscanf(arg, "%d:%d:%d",
&options->max_startups_begin,
&options->max_startups_rate,
&options->max_startups)) == 3) {
if (options->max_startups_begin >
options->max_startups ||
options->max_startups_rate > 100 ||
options->max_startups_rate < 1)
fatal("%s line %d: Illegal MaxStartups spec.",
filename, linenum);
} else if (n != 1)
fatal("%s line %d: Illegal MaxStartups spec.",
filename, linenum);
else
options->max_startups = options->max_startups_begin;
break;
case sMaxAuthTries:
intptr = &options->max_authtries;
goto parse_int;
case sBanner:
charptr = &options->banner;
goto parse_filename;
/*
* These options can contain %X options expanded at
* connect time, so that you can specify paths like:
*
* AuthorizedKeysFile /etc/ssh_keys/%u
*/
case sAuthorizedKeysFile:
case sAuthorizedKeysFile2:
charptr = (opcode == sAuthorizedKeysFile) ?
&options->authorized_keys_file :
&options->authorized_keys_file2;
goto parse_filename;
case sClientAliveInterval:
intptr = &options->client_alive_interval;
goto parse_time;
case sClientAliveCountMax:
intptr = &options->client_alive_count_max;
goto parse_int;
case sAcceptEnv:
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (strchr(arg, '=') != NULL)
fatal("%s line %d: Invalid environment name.",
filename, linenum);
if (options->num_accept_env >= MAX_ACCEPT_ENV)
fatal("%s line %d: too many allow env.",
filename, linenum);
if (!*activep)
break;
options->accept_env[options->num_accept_env++] =
xstrdup(arg);
}
break;
case sPermitTunnel:
intptr = &options->permit_tun;
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing yes/point-to-point/"
"ethernet/no argument.", filename, linenum);
value = 0; /* silence compiler */
if (strcasecmp(arg, "ethernet") == 0)
value = SSH_TUNMODE_ETHERNET;
else if (strcasecmp(arg, "point-to-point") == 0)
value = SSH_TUNMODE_POINTOPOINT;
else if (strcasecmp(arg, "yes") == 0)
value = SSH_TUNMODE_YES;
else if (strcasecmp(arg, "no") == 0)
value = SSH_TUNMODE_NO;
else
fatal("%s line %d: Bad yes/point-to-point/ethernet/"
"no argument: %s", filename, linenum, arg);
if (*intptr == -1)
*intptr = value;
break;
case sMatch:
if (cmdline)
fatal("Match directive not supported as a command-line "
"option");
value = match_cfg_line(&cp, linenum, user, host, address);
if (value < 0)
fatal("%s line %d: Bad Match condition", filename,
linenum);
*activep = value;
break;
case sPermitOpen:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing PermitOpen specification",
filename, linenum);
n = options->num_permitted_opens; /* modified later */
if (strcmp(arg, "any") == 0) {
if (*activep && n == -1) {
channel_clear_adm_permitted_opens();
options->num_permitted_opens = 0;
}
break;
}
if (*activep && n == -1)
channel_clear_adm_permitted_opens();
for (; arg != NULL && *arg != '\0'; arg = strdelim(&cp)) {
p = hpdelim(&arg);
if (p == NULL)
fatal("%s line %d: missing host in PermitOpen",
filename, linenum);
p = cleanhostname(p);
if (arg == NULL || (port = a2port(arg)) == 0)
fatal("%s line %d: bad port number in "
"PermitOpen", filename, linenum);
if (*activep && n == -1)
options->num_permitted_opens =
channel_add_adm_permitted_opens(p, port);
}
break;
case sForceCommand:
if (cp == NULL)
fatal("%.200s line %d: Missing argument.", filename,
linenum);
len = strspn(cp, WHITESPACE);
if (*activep && options->adm_forced_command == NULL)
options->adm_forced_command = xstrdup(cp + len);
return 0;
case sChrootDirectory:
charptr = &options->chroot_directory;
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing file name.",
filename, linenum);
if (*activep && *charptr == NULL)
*charptr = xstrdup(arg);
break;
case sDeprecated:
logit("%s line %d: Deprecated option %s",
filename, linenum, arg);
while (arg)
arg = strdelim(&cp);
break;
case sUnsupported:
logit("%s line %d: Unsupported option %s",
filename, linenum, arg);
while (arg)
arg = strdelim(&cp);
break;
default:
fatal("%s line %d: Missing handler for opcode %s (%d)",
filename, linenum, arg, opcode);
}
if ((arg = strdelim(&cp)) != NULL && *arg != '\0')
fatal("%s line %d: garbage at end of line; \"%.200s\".",
filename, linenum, arg);
return 0;
}
/* Reads the server configuration file. */
void
load_server_config(const char *filename, Buffer *conf)
{
char line[1024], *cp;
FILE *f;
debug2("%s: filename %s", __func__, filename);
if ((f = fopen(filename, "r")) == NULL) {
perror(filename);
exit(1);
}
buffer_clear(conf);
while (fgets(line, sizeof(line), f)) {
/*
* Trim out comments and strip whitespace
* NB - preserve newlines, they are needed to reproduce
* line numbers later for error messages
*/
if ((cp = strchr(line, '#')) != NULL)
memcpy(cp, "\n", 2);
cp = line + strspn(line, " \t\r");
buffer_append(conf, cp, strlen(cp));
}
buffer_append(conf, "\0", 1);
fclose(f);
debug2("%s: done config len = %d", __func__, buffer_len(conf));
}
void
parse_server_match_config(ServerOptions *options, const char *user,
const char *host, const char *address)
{
ServerOptions mo;
initialize_server_options(&mo);
parse_server_config(&mo, "reprocess config", &cfg, user, host, address);
copy_set_server_options(options, &mo, 0);
}
/* Helper macros */
#define M_CP_INTOPT(n) do {\
if (src->n != -1) \
dst->n = src->n; \
} while (0)
#define M_CP_STROPT(n) do {\
if (src->n != NULL) { \
if (dst->n != NULL) \
xfree(dst->n); \
dst->n = src->n; \
} \
} while(0)
/*
* Copy any supported values that are set.
*
* If the preauth flag is set, we do not bother copying the the string or
* array values that are not used pre-authentication, because any that we
* do use must be explictly sent in mm_getpwnamallow().
*/
void
copy_set_server_options(ServerOptions *dst, ServerOptions *src, int preauth)
{
M_CP_INTOPT(password_authentication);
M_CP_INTOPT(gss_authentication);
M_CP_INTOPT(rsa_authentication);
M_CP_INTOPT(pubkey_authentication);
M_CP_INTOPT(kerberos_authentication);
M_CP_INTOPT(hostbased_authentication);
M_CP_INTOPT(kbd_interactive_authentication);
M_CP_INTOPT(permit_root_login);
M_CP_INTOPT(allow_tcp_forwarding);
M_CP_INTOPT(gateway_ports);
M_CP_INTOPT(x11_display_offset);
M_CP_INTOPT(x11_forwarding);
M_CP_INTOPT(x11_use_localhost);
M_CP_STROPT(banner);
if (preauth)
return;
M_CP_STROPT(adm_forced_command);
M_CP_STROPT(chroot_directory);
}
#undef M_CP_INTOPT
#undef M_CP_STROPT
void
parse_server_config(ServerOptions *options, const char *filename, Buffer *conf,
const char *user, const char *host, const char *address)
{
int active, linenum, bad_options = 0;
char *cp, *obuf, *cbuf;
debug2("%s: config %s len %d", __func__, filename, buffer_len(conf));
obuf = cbuf = xstrdup(buffer_ptr(conf));
active = user ? 0 : 1;
linenum = 1;
while ((cp = strsep(&cbuf, "\n")) != NULL) {
if (process_server_config_line(options, cp, filename,
linenum++, &active, user, host, address) != 0)
bad_options++;
}
xfree(obuf);
if (bad_options > 0)
fatal("%s: terminating, %d bad configuration options",
filename, bad_options);
}
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