xref: /onnv-gate/usr/src/cmd/ssh/sshd/servconf.c (revision 5562:0f12179b71ab)

/*
 * 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".
 */
/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include "includes.h"
RCSID("$OpenBSD: servconf.c,v 1.115 2002/09/04 18:52:42 stevesk Exp $");

#pragma ident	"%Z%%M%	%I%	%E% SMI"

#ifdef HAVE_DEFOPEN
#include <deflt.h>
#endif /* HAVE_DEFOPEN */

#if defined(KRB4)
#include <krb.h>
#endif
#if defined(KRB5)
#ifdef HEIMDAL
#include <krb.h>
#else
/* Bodge - but then, so is using the kerberos IV KEYFILE to get a Kerberos V
 * keytab */
#define KEYFILE "/etc/krb5.keytab"
#endif
#endif
#ifdef AFS
#include <kafs.h>
#endif

#include "ssh.h"
#include "log.h"
#include "servconf.h"
#include "xmalloc.h"
#include "compat.h"
#include "pathnames.h"
#include "tildexpand.h"
#include "misc.h"
#include "cipher.h"
#include "kex.h"
#include "mac.h"
#include "auth.h"

static void add_listen_addr(ServerOptions *, char *, u_short);
static void add_one_listen_addr(ServerOptions *, char *, u_short);

/* AF_UNSPEC or AF_INET or AF_INET6 */
extern int IPv4or6;

/* Initializes the server options to their default values. */

void
initialize_server_options(ServerOptions *options)
{
	(void) memset(options, 0, sizeof(*options));

	/* Portable-specific options */
	options->pam_authentication_via_kbd_int = -1;

	/* Standard Options */
	options->num_ports = 0;
	options->ports_from_cmdline = 0;
	options->listen_addrs = NULL;
	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->keepalives = -1;
	options->log_facility = SYSLOG_FACILITY_NOT_SET;
	options->log_level = SYSLOG_LEVEL_NOT_SET;
	options->rhosts_authentication = -1;
	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;
#ifdef GSSAPI
	options->gss_authentication = -1;
	options->gss_keyex = -1;
	options->gss_store_creds = -1;
	options->gss_use_session_ccache = -1;
	options->gss_cleanup_creds = -1;
#endif
#if defined(KRB4) || defined(KRB5)
	options->kerberos_authentication = -1;
	options->kerberos_or_local_passwd = -1;
	options->kerberos_ticket_cleanup = -1;
#endif
#if defined(AFS) || defined(KRB5)
	options->kerberos_tgt_passing = -1;
#endif
#ifdef AFS
	options->afs_token_passing = -1;
#endif
	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->banner = NULL;
	options->verify_reverse_mapping = -1;
	options->client_alive_interval = -1;
	options->client_alive_count_max = -1;
	options->authorized_keys_file = NULL;
	options->authorized_keys_file2 = NULL;

	options->max_auth_tries = -1;
	options->max_auth_tries_log = -1;

	options->max_init_auth_tries = -1;
	options->max_init_auth_tries_log = -1;

	options->lookup_client_hostnames = -1;
}

#ifdef HAVE_DEFOPEN
/*
 * Reads /etc/default/login and defaults several ServerOptions:
 *
 * PermitRootLogin
 * PermitEmptyPasswords
 * LoginGraceTime
 *
 * CONSOLE=*      -> PermitRootLogin=without-password
 * #CONSOLE=*     -> PermitRootLogin=yes
 *
 * PASSREQ=YES    -> PermitEmptyPasswords=no
 * PASSREQ=NO     -> PermitEmptyPasswords=yes
 * #PASSREQ=*     -> PermitEmptyPasswords=no
 *
 * TIMEOUT=<secs> -> LoginGraceTime=<secs>
 * #TIMEOUT=<secs> -> LoginGraceTime=300
 */
static
void
deflt_fill_default_server_options(ServerOptions *options)
{
	int	flags;
	char	*ptr;

	if (defopen(_PATH_DEFAULT_LOGIN))
		return;

	/* Ignore case */
	flags = defcntl(DC_GETFLAGS, 0);
	TURNOFF(flags, DC_CASE);
	(void) defcntl(DC_SETFLAGS, flags);

	if (options->permit_root_login == PERMIT_NOT_SET &&
	    (ptr = defread("CONSOLE=")) != NULL)
		options->permit_root_login = PERMIT_NO_PASSWD;

	if (options->permit_empty_passwd == -1 &&
	    (ptr = defread("PASSREQ=")) != NULL) {
		if (strcasecmp("YES", ptr) == 0)
			options->permit_empty_passwd = 0;
		else if (strcasecmp("NO", ptr) == 0)
			options->permit_empty_passwd = 1;
	}

	if (options->max_init_auth_tries == -1 &&
	    (ptr = defread("RETRIES=")) != NULL) {
		options->max_init_auth_tries = atoi(ptr);
	}

	if (options->max_init_auth_tries_log == -1 &&
	    (ptr = defread("SYSLOG_FAILED_LOGINS=")) != NULL) {
		options->max_init_auth_tries_log = atoi(ptr);
	}

	if (options->login_grace_time == -1) {
		if ((ptr = defread("TIMEOUT=")) != NULL)
			options->login_grace_time = (unsigned)atoi(ptr);
		else
			options->login_grace_time = 300;
	}

	(void) defopen((char *)NULL);
}
#endif /* HAVE_DEFOPEN */

void
fill_default_server_options(ServerOptions *options)
{

#ifdef HAVE_DEFOPEN
	deflt_fill_default_server_options(options);
#endif /* HAVE_DEFOPEN */

	/* Portable-specific options */
	if (options->pam_authentication_via_kbd_int == -1)
		options->pam_authentication_via_kbd_int = 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;
#ifndef GSSAPI
		/* With GSS keyex we can run v2 w/ no host keys */
		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;
		}
#endif /* GSSAPI */
	}
	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 = 1;
	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->keepalives == -1)
		options->keepalives = 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_authentication == -1)
		options->rhosts_authentication = 0;
	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;
#ifdef GSSAPI
	if (options->gss_authentication == -1)
		options->gss_authentication = 1;
	if (options->gss_keyex == -1)
		options->gss_keyex = 1;
	if (options->gss_store_creds == -1)
		options->gss_store_creds = 1;
	if (options->gss_use_session_ccache == -1)
		options->gss_use_session_ccache = 1;
	if (options->gss_cleanup_creds == -1)
		options->gss_cleanup_creds = 1;
#endif
#if defined(KRB4) || defined(KRB5)
	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;
#endif
#if defined(AFS) || defined(KRB5)
	if (options->kerberos_tgt_passing == -1)
		options->kerberos_tgt_passing = 0;
#endif
#ifdef AFS
	if (options->afs_token_passing == -1)
		options->afs_token_passing = 0;
#endif
	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 = 1;
	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->verify_reverse_mapping == -1)
		options->verify_reverse_mapping = 0;
	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->max_auth_tries == -1)
		options->max_auth_tries = AUTH_FAIL_MAX;
	if (options->max_auth_tries_log == -1)
		options->max_auth_tries_log = options->max_auth_tries / 2;

	if (options->max_init_auth_tries == -1)
		options->max_init_auth_tries = AUTH_FAIL_MAX;
	if (options->max_init_auth_tries_log == -1)
		options->max_init_auth_tries_log = options->max_init_auth_tries / 2;

	if (options->lookup_client_hostnames == -1)
		options->lookup_client_hostnames = 1;
}

/* Keyword tokens. */
typedef enum {
	sBadOption,		/* == unknown option */
	/* Portable-specific options */
	sPAMAuthenticationViaKbdInt,
	/* Standard Options */
	sPort, sHostKeyFile, sServerKeyBits, sLoginGraceTime, sKeyRegenerationTime,
	sPermitRootLogin, sLogFacility, sLogLevel,
	sRhostsAuthentication, sRhostsRSAAuthentication, sRSAAuthentication,
#ifdef GSSAPI
	sGssAuthentication, sGssKeyEx, sGssStoreDelegCreds,
	sGssUseSessionCredCache, sGssCleanupCreds,
#endif /* GSSAPI */
#if defined(KRB4) || defined(KRB5)
	sKerberosAuthentication, sKerberosOrLocalPasswd, sKerberosTicketCleanup,
#endif
#if defined(AFS) || defined(KRB5)
	sKerberosTgtPassing,
#endif
#ifdef AFS
	sAFSTokenPassing,
#endif
	sChallengeResponseAuthentication,
	sPasswordAuthentication, sKbdInteractiveAuthentication, sListenAddress,
	sPrintMotd, sPrintLastLog, sIgnoreRhosts,
	sX11Forwarding, sX11DisplayOffset, sX11UseLocalhost,
	sStrictModes, sEmptyPasswd, sKeepAlives,
	sPermitUserEnvironment, sUseLogin, sAllowTcpForwarding, sCompression,
	sAllowUsers, sDenyUsers, sAllowGroups, sDenyGroups,
	sIgnoreUserKnownHosts, sCiphers, sMacs, sProtocol, sPidFile,
	sGatewayPorts, sPubkeyAuthentication, sXAuthLocation, sSubsystem, sMaxStartups,
	sBanner, sVerifyReverseMapping, sHostbasedAuthentication,
	sHostbasedUsesNameFromPacketOnly, sClientAliveInterval,
	sClientAliveCountMax, sAuthorizedKeysFile, sAuthorizedKeysFile2,
	sMaxAuthTries, sMaxAuthTriesLog, sUsePrivilegeSeparation,
	sLookupClientHostnames,
	sDeprecated
} ServerOpCodes;

/* Textual representation of the tokens. */
static struct {
	const char *name;
	ServerOpCodes opcode;
} keywords[] = {
	/* Portable-specific options */
	{ "PAMAuthenticationViaKbdInt", sPAMAuthenticationViaKbdInt },
	/* Standard Options */
	{ "port", sPort },
	{ "hostkey", sHostKeyFile },
	{ "hostdsakey", sHostKeyFile },					/* alias */
	{ "pidfile", sPidFile },
	{ "serverkeybits", sServerKeyBits },
	{ "logingracetime", sLoginGraceTime },
	{ "keyregenerationinterval", sKeyRegenerationTime },
	{ "permitrootlogin", sPermitRootLogin },
	{ "syslogfacility", sLogFacility },
	{ "loglevel", sLogLevel },
	{ "rhostsauthentication", sRhostsAuthentication },
	{ "rhostsrsaauthentication", sRhostsRSAAuthentication },
	{ "hostbasedauthentication", sHostbasedAuthentication },
	{ "hostbasedusesnamefrompacketonly", sHostbasedUsesNameFromPacketOnly },
	{ "rsaauthentication", sRSAAuthentication },
	{ "pubkeyauthentication", sPubkeyAuthentication },
	{ "dsaauthentication", sPubkeyAuthentication },			/* alias */
#ifdef GSSAPI
	{ "gssapiauthentication", sGssAuthentication },
	{ "gssapikeyexchange", sGssKeyEx },
	{ "gssapistoredelegatedcredentials", sGssStoreDelegCreds },
	{ "gssauthentication", sGssAuthentication },			/* alias */
	{ "gsskeyex", sGssKeyEx },					/* alias */
	{ "gssstoredelegcreds", sGssStoreDelegCreds },			/* alias */
#ifndef SUNW_GSSAPI
	{ "gssusesessionccache", sGssUseSessionCredCache },
	{ "gssusesessioncredcache", sGssUseSessionCredCache },
	{ "gsscleanupcreds", sGssCleanupCreds },
#endif /* SUNW_GSSAPI */
#endif
#if defined(KRB4) || defined(KRB5)
	{ "kerberosauthentication", sKerberosAuthentication },
	{ "kerberosorlocalpasswd", sKerberosOrLocalPasswd },
	{ "kerberosticketcleanup", sKerberosTicketCleanup },
#endif
#if defined(AFS) || defined(KRB5)
	{ "kerberostgtpassing", sKerberosTgtPassing },
#endif
#ifdef AFS
	{ "afstokenpassing", sAFSTokenPassing },
#endif
	{ "passwordauthentication", sPasswordAuthentication },
	{ "kbdinteractiveauthentication", sKbdInteractiveAuthentication },
	{ "challengeresponseauthentication", sChallengeResponseAuthentication },
	{ "skeyauthentication", sChallengeResponseAuthentication }, /* alias */
	{ "checkmail", sDeprecated },
	{ "listenaddress", sListenAddress },
	{ "printmotd", sPrintMotd },
	{ "printlastlog", sPrintLastLog },
	{ "ignorerhosts", sIgnoreRhosts },
	{ "ignoreuserknownhosts", sIgnoreUserKnownHosts },
	{ "x11forwarding", sX11Forwarding },
	{ "x11displayoffset", sX11DisplayOffset },
	{ "x11uselocalhost", sX11UseLocalhost },
	{ "xauthlocation", sXAuthLocation },
	{ "strictmodes", sStrictModes },
	{ "permitemptypasswords", sEmptyPasswd },
	{ "permituserenvironment", sPermitUserEnvironment },
	{ "uselogin", sUseLogin },
	{ "compression", sCompression },
	{ "keepalive", sKeepAlives },
	{ "allowtcpforwarding", sAllowTcpForwarding },
	{ "allowusers", sAllowUsers },
	{ "denyusers", sDenyUsers },
	{ "allowgroups", sAllowGroups },
	{ "denygroups", sDenyGroups },
	{ "ciphers", sCiphers },
	{ "macs", sMacs },
	{ "protocol", sProtocol },
	{ "gatewayports", sGatewayPorts },
	{ "subsystem", sSubsystem },
	{ "maxstartups", sMaxStartups },
	{ "banner", sBanner },
	{ "verifyreversemapping", sVerifyReverseMapping },
	{ "reversemappingcheck", sVerifyReverseMapping },
	{ "clientaliveinterval", sClientAliveInterval },
	{ "clientalivecountmax", sClientAliveCountMax },
	{ "authorizedkeysfile", sAuthorizedKeysFile },
	{ "authorizedkeysfile2", sAuthorizedKeysFile2 },
	{ "maxauthtries", sMaxAuthTries },
	{ "maxauthtrieslog", sMaxAuthTriesLog },
	{ "useprivilegeseparation", sUsePrivilegeSeparation},
	{ "lookupclienthostnames", sLookupClientHostnames},
	{ NULL, sBadOption }
};

/*
 * 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 i;

	for (i = 0; keywords[i].name; i++)
		if (strcasecmp(cp, keywords[i].name) == 0)
			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)
{
	int i;

	if (options->num_ports == 0)
		options->ports[options->num_ports++] = SSH_DEFAULT_PORT;
	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;

	(void) memset(&hints, 0, sizeof(hints));
	hints.ai_family = IPv4or6;
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_flags = (addr == NULL) ? AI_PASSIVE : 0;
	(void) snprintf(strport, sizeof strport, "%u", port);
	if ((gaierr = getaddrinfo(addr, strport, &hints, &aitop)) != 0)
		fatal("bad addr or host: %s (%s)",
		    addr ? addr : "<NULL>",
		    gai_strerror(gaierr));
	for (ai = aitop; ai->ai_next; ai = ai->ai_next)
		;
	ai->ai_next = options->listen_addrs;
	options->listen_addrs = aitop;
}

int
process_server_config_line(ServerOptions *options, char *line,
    const char *filename, int linenum)
{
	char *cp, **charptr, *arg, *p;
	int *intptr, value, i, n;
	ServerOpCodes opcode;

	cp = line;
	arg = strdelim(&cp);
	/* 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);
	switch (opcode) {
	/* Portable-specific options */
	case sPAMAuthenticationViaKbdInt:
		intptr = &options->pam_authentication_via_kbd_int;
		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 (*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 || *arg == '\0' || strncmp(arg, "[]", 2) == 0)
			fatal("%s line %d: missing inet addr.",
			    filename, linenum);
		if (*arg == '[') {
			if ((p = strchr(arg, ']')) == NULL)
				fatal("%s line %d: bad ipv6 inet addr usage.",
				    filename, linenum);
			arg++;
			(void) memmove(p, p+1, strlen(p+1)+1);
		} else if (((p = strchr(arg, ':')) == NULL) ||
			    (strchr(p+1, ':') != NULL)) {
			add_listen_addr(options, arg, 0);
			break;
		}
		if (*p == ':') {
			u_short port;

			p++;
			if (*p == '\0')
				fatal("%s line %d: bad inet addr:port usage.",
				    filename, linenum);
			else {
				*(p-1) = '\0';
				if ((port = a2port(p)) == 0)
					fatal("%s line %d: bad port number.",
					    filename, linenum);
				add_listen_addr(options, arg, port);
			}
		} else if (*p == '\0')
			add_listen_addr(options, arg, 0);
		else
			fatal("%s line %d: bad inet addr usage.",
			    filename, linenum);
		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 (*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 (*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 (*intptr == -1)
			*intptr = value;
		break;

	case sIgnoreUserKnownHosts:
		intptr = &options->ignore_user_known_hosts;
		goto parse_flag;

	case sRhostsAuthentication:
		intptr = &options->rhosts_authentication;
		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;
#ifdef GSSAPI
	case sGssAuthentication:
		intptr = &options->gss_authentication;
		goto parse_flag;
	case sGssKeyEx:
		intptr = &options->gss_keyex;
		goto parse_flag;
	case sGssStoreDelegCreds:
		intptr = &options->gss_keyex;
		goto parse_flag;
#ifndef SUNW_GSSAPI
	case sGssUseSessionCredCache:
		intptr = &options->gss_use_session_ccache;
		goto parse_flag;
	case sGssCleanupCreds:
		intptr = &options->gss_cleanup_creds;
		goto parse_flag;
#endif /* SUNW_GSSAPI */
#endif /* GSSAPI */
#if defined(KRB4) || defined(KRB5)
	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;
#endif
#if defined(AFS) || defined(KRB5)
	case sKerberosTgtPassing:
		intptr = &options->kerberos_tgt_passing;
		goto parse_flag;
#endif
#ifdef AFS
	case sAFSTokenPassing:
		intptr = &options->afs_token_passing;
		goto parse_flag;
#endif

	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 sKeepAlives:
		intptr = &options->keepalives;
		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;
		goto parse_flag;

	case sGatewayPorts:
		arg = strdelim(&cp);
		if (get_yes_no_flag(&options->gateway_ports, arg, filename,
		    linenum, 1) == 1)
			break;

		if (strcmp(arg, "clientspecified") == 0)
			options->gateway_ports = 2;
		else
			fatal("%.200s line %d: Bad yes/no/clientspecified "
			    "argument.", filename, linenum);
		break;

	case sVerifyReverseMapping:
		intptr = &options->verify_reverse_mapping;
		goto parse_flag;

	case sLogFacility:
		intptr = (int *) &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 (*intptr == -1)
			*intptr = (SyslogFacility) value;
		break;

	case sLogLevel:
		intptr = (int *) &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 (*intptr == -1)
			*intptr = (LogLevel) value;
		break;

	case sAllowTcpForwarding:
		intptr = &options->allow_tcp_forwarding;
		goto parse_flag;

	case sUsePrivilegeSeparation:
		log("%s line %d: ignoring UsePrivilegeSeparation option value."
		    " This option is always on.", filename, linenum);
		while (arg)
		    arg = strdelim(&cp);
		break;

	case sAllowUsers:
		while (((arg = strdelim(&cp)) != NULL) && *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)) != NULL) && *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)) != NULL) && *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)) != NULL) && *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);
		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);
		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 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 sMaxAuthTries:
		intptr = &options->max_auth_tries;
		goto parse_int;

	case sMaxAuthTriesLog:
		intptr = &options->max_auth_tries_log;
		goto parse_int;

	case sLookupClientHostnames:
		intptr = &options->lookup_client_hostnames;
		goto parse_flag;

	case sDeprecated:
		log("%s line %d: Deprecated 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
read_server_config(ServerOptions *options, const char *filename)
{
	int linenum, bad_options = 0;
	char line[1024];
	FILE *f;

	f = fopen(filename, "r");
	if (!f) {
		perror(filename);
		exit(1);
	}
	linenum = 0;
	while (fgets(line, sizeof(line), f)) {
		/* Update line number counter. */
		linenum++;
		if (process_server_config_line(options, line, filename, linenum) != 0)
			bad_options++;
	}
	(void) fclose(f);
	if (bad_options > 0)
		fatal("%s: terminating, %d bad configuration options",
		    filename, bad_options);
}