add KEX_GSS_GRP14_SHA1 handling

[gssapi-openssh.git] / openssh / servconf.c

/* $OpenBSD: servconf.c,v 1.165 2006/08/14 12:40:25 dtucker 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;
#ifdef  SESSION_HOOKS
        options->session_hooks_allow = -1;
        options->session_hooks_startup_cmd = NULL;
        options->session_hooks_shutdown_cmd = NULL;
#endif
	options->kerberos_get_afs_token = -1;
	options->gss_authentication=-1;
	options->gss_keyex = -1;
	options->gss_cleanup_creds = -1;
	options->gss_strict_acceptor = -1;
	options->gsi_allow_limited_proxy = -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->none_enabled = -1;
        options->tcp_rcv_buf_poll = -1;
        options->hpn_disabled = -1;
        options->hpn_buffer_size = -1;
}

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 = 1;
	if (options->gss_keyex == -1)
		options->gss_keyex = 1;
	if (options->gss_cleanup_creds == -1)
		options->gss_cleanup_creds = 1;
	if (options->gss_strict_acceptor == -1)
		options->gss_strict_acceptor = 0;
	if (options->gsi_allow_limited_proxy == -1)
		options->gsi_allow_limited_proxy = 0;
	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;

	if (options->hpn_disabled == -1) 
		options->hpn_disabled = 0;

	if (options->hpn_buffer_size == -1)
	        options->hpn_buffer_size = 2*1024*1024;
	else {
		if (options->hpn_buffer_size == 0)
			options->hpn_buffer_size = 1;
		/* limit the maximum buffer to 7MB */
		if (options->hpn_buffer_size > 7168)
			options->hpn_buffer_size = 7168;
		options->hpn_buffer_size *=1024;
	}

	/* 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,
#ifdef SESSION_HOOKS
        sAllowSessionHooks, sSessionHookStartupCmd, sSessionHookShutdownCmd,
#endif
	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, sGssStrictAcceptor,
	sGssKeyEx, 
    sGssCredsPath,
	sGsiAllowLimitedProxy,
    sAcceptEnv, sPermitTunnel,
	sMatch, sPermitOpen, sForceCommand,
	sUsePrivilegeSeparation,
    sNoneEnabled, sTcpRcvBufPoll, 
	sHPNDisabled, sHPNBufferSize,
	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_GLOBAL },
	{ "syslogfacility", sLogFacility, SSHCFG_GLOBAL },
	{ "loglevel", sLogLevel, SSHCFG_GLOBAL },
	{ "rhostsauthentication", sDeprecated, SSHCFG_GLOBAL },
	{ "rhostsrsaauthentication", sRhostsRSAAuthentication, SSHCFG_GLOBAL },
	{ "hostbasedauthentication", sHostbasedAuthentication, SSHCFG_GLOBAL },
	{ "hostbasedusesnamefrompacketonly", sHostbasedUsesNameFromPacketOnly, SSHCFG_GLOBAL },
	{ "rsaauthentication", sRSAAuthentication, SSHCFG_GLOBAL },
	{ "pubkeyauthentication", sPubkeyAuthentication, SSHCFG_GLOBAL },
	{ "dsaauthentication", sPubkeyAuthentication, SSHCFG_GLOBAL },	/* alias */
#ifdef KRB5
	{ "kerberosauthentication", sKerberosAuthentication, SSHCFG_GLOBAL },
	{ "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_GLOBAL },
	{ "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_GLOBAL },
	{ "gssapicleanupcredentials", sGssCleanupCreds, SSHCFG_GLOBAL },
	{ "gssapicredentialspath", sGssCredsPath, SSHCFG_GLOBAL },
	{ "gssapistrictacceptorcheck", sGssStrictAcceptor, SSHCFG_GLOBAL },
	{ "gssapikeyexchange", sGssKeyEx, SSHCFG_GLOBAL },
#ifdef GSI
	{ "gsiallowlimitedproxy", sGsiAllowLimitedProxy, SSHCFG_GLOBAL },
#endif
#else
	{ "gssapiauthentication", sUnsupported, SSHCFG_GLOBAL },
	{ "gssapicleanupcredentials", sUnsupported, SSHCFG_GLOBAL },
	{ "gssapicredentialspath", sUnsupported, SSHCFG_GLOBAL },
	{ "gssapistrictacceptorcheck", sUnsupported, SSHCFG_GLOBAL },
	{ "gssapikeyexchange", sUnsupported, SSHCFG_GLOBAL },
#ifdef GSI
	{ "gsiallowlimitedproxy", sUnsupported, SSHCFG_GLOBAL },
#endif
#endif
#ifdef SESSION_HOOKS
    { "allowsessionhooks", sAllowSessionHooks, SSHCFG_GLOBAL },
    { "sessionhookstartupcmd", sSessionHookStartupCmd, SSHCFG_GLOBAL },
    { "sessionhookshutdowncmd", sSessionHookShutdownCmd, SSHCFG_GLOBAL },
#endif        
	{ "passwordauthentication", sPasswordAuthentication, SSHCFG_GLOBAL },
	{ "kbdinteractiveauthentication", sKbdInteractiveAuthentication, SSHCFG_GLOBAL },
	{ "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_GLOBAL },
	{ "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 },
    { "noneenabled", sNoneEnabled },
        { "hpndisabled", sHPNDisabled },
        { "hpnbuffersize", sHPNBufferSize },
        { "tcprcvbufpoll", sTcpRcvBufPoll },
	{ 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>",
		    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) {
			debug("address '%s' arg '%s'", address, arg);
			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;
	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 (*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 sNoneEnabled:
		intptr = &options->none_enabled;
		goto parse_flag;

	case sTcpRcvBufPoll:
		intptr = &options->tcp_rcv_buf_poll;
		goto parse_flag;

	case sHPNDisabled:
		intptr = &options->hpn_disabled;
		goto parse_flag;

	case sHPNBufferSize:
		intptr = &options->hpn_buffer_size;
		goto parse_int;

	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 sGssKeyEx:
		intptr = &options->gss_keyex;
		goto parse_flag;

	case sGssCleanupCreds:
		intptr = &options->gss_cleanup_creds;
		goto parse_flag;

	case sGssCredsPath:
		charptr = &options->gss_creds_path;
		goto parse_filename;

	case sGssStrictAcceptor:
		intptr = &options->gss_strict_acceptor;
		goto parse_flag;

	case sGsiAllowLimitedProxy:
		intptr = &options->gsi_allow_limited_proxy;
		goto parse_flag;

#ifdef SESSION_HOOKS
        case sAllowSessionHooks:
                intptr = &options->session_hooks_allow;
                goto parse_flag;
        case sSessionHookStartupCmd:
        case sSessionHookShutdownCmd:
                arg = strdelim(&cp);
                if (!arg || *arg == '\0')
                    fatal("%s line %d: empty session hook command",
                          filename, linenum);
                if (opcode==sSessionHookStartupCmd)
                    options->session_hooks_startup_cmd = strdup(arg);
                else
                    options->session_hooks_shutdown_cmd = strdup(arg);
                break;
#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 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 (*intptr == -1)
			*intptr = value;
		break;

	case sUseDNS:
		intptr = &options->use_dns;
		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:
		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);
		if (strcmp(arg, "any") == 0) {
			if (*activep) {
				channel_clear_adm_permitted_opens();
				options->num_permitted_opens = 0;
			}
			break;
		}
		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 && options->num_permitted_opens == -1) {
				channel_clear_adm_permitted_opens();
				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 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);
}

/* Copy any (supported) values that are set */
void
copy_set_server_options(ServerOptions *dst, ServerOptions *src)
{
	if (src->allow_tcp_forwarding != -1)
		dst->allow_tcp_forwarding = src->allow_tcp_forwarding;
	if (src->gateway_ports != -1)
		dst->gateway_ports = src->gateway_ports;
	if (src->adm_forced_command != NULL) {
		if (dst->adm_forced_command != NULL)
			xfree(dst->adm_forced_command);
		dst->adm_forced_command = src->adm_forced_command;
	}
	if (src->x11_display_offset != -1)
		dst->x11_display_offset = src->x11_display_offset;
	if (src->x11_forwarding != -1)
		dst->x11_forwarding = src->x11_forwarding;
	if (src->x11_use_localhost != -1)
		dst->x11_use_localhost = src->x11_use_localhost;
}

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);
}