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/* $OpenBSD: servconf.c,v 1.250 2014/07/03 22:40:43 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 <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <ctype.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 <errno.h>
#ifdef HAVE_UTIL_H
#include <util.h>
#endif
#include "openbsd-compat/sys-queue.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"
#include "canohost.h"
#include "packet.h"
#include "hostfile.h"
#include "auth.h"
static void add_listen_addr(ServerOptions *, char *, int);
static void add_one_listen_addr(ServerOptions *, char *, int);
/* 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->num_host_cert_files = 0;
options->host_key_agent = NULL;
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->permit_tty = -1;
options->permit_user_rc = -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->rekey_limit = -1;
options->rekey_interval = -1;
options->allow_tcp_forwarding = -1;
options->allow_agent_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->kex_algorithms = 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->max_sessions = -1;
options->banner = NULL;
options->use_dns = -1;
options->client_alive_interval = -1;
options->client_alive_count_max = -1;
options->num_authkeys_files = 0;
options->num_accept_env = 0;
options->permit_tun = -1;
options->num_permitted_opens = -1;
options->adm_forced_command = NULL;
options->chroot_directory = NULL;
options->authorized_keys_command = NULL;
options->authorized_keys_command_user = NULL;
options->revoked_keys_file = NULL;
options->trusted_user_ca_keys = NULL;
options->authorized_principals_file = NULL;
options->ip_qos_interactive = -1;
options->ip_qos_bulk = -1;
options->version_addendum = 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_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;
#ifdef OPENSSL_HAS_ECC
options->host_key_files[options->num_host_key_files++] =
_PATH_HOST_ECDSA_KEY_FILE;
#endif
options->host_key_files[options->num_host_key_files++] =
_PATH_HOST_ED25519_KEY_FILE;
}
}
/* No certificates by default */
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 = 1024;
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->permit_tty == -1)
options->permit_tty = 1;
if (options->permit_user_rc == -1)
options->permit_user_rc = 1;
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->rekey_limit == -1)
options->rekey_limit = 0;
if (options->rekey_interval == -1)
options->rekey_interval = 0;
if (options->allow_tcp_forwarding == -1)
options->allow_tcp_forwarding = FORWARD_ALLOW;
if (options->allow_agent_forwarding == -1)
options->allow_agent_forwarding = 1;
if (options->gateway_ports == -1)
options->gateway_ports = 0;
if (options->max_startups == -1)
options->max_startups = 100;
if (options->max_startups_rate == -1)
options->max_startups_rate = 30; /* 30% */
if (options->max_startups_begin == -1)
options->max_startups_begin = 10;
if (options->max_authtries == -1)
options->max_authtries = DEFAULT_AUTH_FAIL_MAX;
if (options->max_sessions == -1)
options->max_sessions = DEFAULT_SESSIONS_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->num_authkeys_files == 0) {
options->authorized_keys_files[options->num_authkeys_files++] =
xstrdup(_PATH_SSH_USER_PERMITTED_KEYS);
options->authorized_keys_files[options->num_authkeys_files++] =
xstrdup(_PATH_SSH_USER_PERMITTED_KEYS2);
}
if (options->permit_tun == -1)
options->permit_tun = SSH_TUNMODE_NO;
if (options->ip_qos_interactive == -1)
options->ip_qos_interactive = IPTOS_LOWDELAY;
if (options->ip_qos_bulk == -1)
options->ip_qos_bulk = IPTOS_THROUGHPUT;
if (options->version_addendum == NULL)
options->version_addendum = xstrdup("");
/* Turn privilege separation on by default */
if (use_privsep == -1)
use_privsep = PRIVSEP_NOSANDBOX;
#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,
sPermitTTY, sStrictModes, sEmptyPasswd, sTCPKeepAlive,
sPermitUserEnvironment, sUseLogin, sAllowTcpForwarding, sCompression,
sRekeyLimit, sAllowUsers, sDenyUsers, sAllowGroups, sDenyGroups,
sIgnoreUserKnownHosts, sCiphers, sMacs, sProtocol, sPidFile,
sGatewayPorts, sPubkeyAuthentication, sXAuthLocation, sSubsystem,
sMaxStartups, sMaxAuthTries, sMaxSessions,
sBanner, sUseDNS, sHostbasedAuthentication,
sHostbasedUsesNameFromPacketOnly, sClientAliveInterval,
sClientAliveCountMax, sAuthorizedKeysFile,
sGssAuthentication, sGssCleanupCreds, sAcceptEnv, sPermitTunnel,
sMatch, sPermitOpen, sForceCommand, sChrootDirectory,
sUsePrivilegeSeparation, sAllowAgentForwarding,
sHostCertificate,
sRevokedKeys, sTrustedUserCAKeys, sAuthorizedPrincipalsFile,
sKexAlgorithms, sIPQoS, sVersionAddendum,
sAuthorizedKeysCommand, sAuthorizedKeysCommandUser,
sAuthenticationMethods, sHostKeyAgent, sPermitUserRC,
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 */
{ "hostkeyagent", sHostKeyAgent, SSHCFG_GLOBAL },
{ "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_ALL },
{ "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_ALL },
{ "permituserenvironment", sPermitUserEnvironment, SSHCFG_GLOBAL },
{ "uselogin", sUseLogin, SSHCFG_GLOBAL },
{ "compression", sCompression, SSHCFG_GLOBAL },
{ "rekeylimit", sRekeyLimit, SSHCFG_ALL },
{ "tcpkeepalive", sTCPKeepAlive, SSHCFG_GLOBAL },
{ "keepalive", sTCPKeepAlive, SSHCFG_GLOBAL }, /* obsolete alias */
{ "allowtcpforwarding", sAllowTcpForwarding, SSHCFG_ALL },
{ "allowagentforwarding", sAllowAgentForwarding, SSHCFG_ALL },
{ "allowusers", sAllowUsers, SSHCFG_ALL },
{ "denyusers", sDenyUsers, SSHCFG_ALL },
{ "allowgroups", sAllowGroups, SSHCFG_ALL },
{ "denygroups", sDenyGroups, SSHCFG_ALL },
{ "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_ALL },
{ "maxsessions", sMaxSessions, SSHCFG_ALL },
{ "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_ALL },
{ "authorizedkeysfile2", sDeprecated, SSHCFG_ALL },
{ "useprivilegeseparation", sUsePrivilegeSeparation, SSHCFG_GLOBAL},
{ "acceptenv", sAcceptEnv, SSHCFG_ALL },
{ "permittunnel", sPermitTunnel, SSHCFG_ALL },
{ "permittty", sPermitTTY, SSHCFG_ALL },
{ "permituserrc", sPermitUserRC, SSHCFG_ALL },
{ "match", sMatch, SSHCFG_ALL },
{ "permitopen", sPermitOpen, SSHCFG_ALL },
{ "forcecommand", sForceCommand, SSHCFG_ALL },
{ "chrootdirectory", sChrootDirectory, SSHCFG_ALL },
{ "hostcertificate", sHostCertificate, SSHCFG_GLOBAL },
{ "revokedkeys", sRevokedKeys, SSHCFG_ALL },
{ "trustedusercakeys", sTrustedUserCAKeys, SSHCFG_ALL },
{ "authorizedprincipalsfile", sAuthorizedPrincipalsFile, SSHCFG_ALL },
{ "kexalgorithms", sKexAlgorithms, SSHCFG_GLOBAL },
{ "ipqos", sIPQoS, SSHCFG_ALL },
{ "authorizedkeyscommand", sAuthorizedKeysCommand, SSHCFG_ALL },
{ "authorizedkeyscommanduser", sAuthorizedKeysCommandUser, SSHCFG_ALL },
{ "versionaddendum", sVersionAddendum, SSHCFG_GLOBAL },
{ "authenticationmethods", sAuthenticationMethods, SSHCFG_ALL },
{ NULL, sBadOption, 0 }
};
static struct {
int val;
char *text;
} tunmode_desc[] = {
{ SSH_TUNMODE_NO, "no" },
{ SSH_TUNMODE_POINTOPOINT, "point-to-point" },
{ SSH_TUNMODE_ETHERNET, "ethernet" },
{ SSH_TUNMODE_YES, "yes" },
{ -1, NULL }
};
/*
* 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;
}
char *
derelativise_path(const char *path)
{
char *expanded, *ret, cwd[MAXPATHLEN];
expanded = tilde_expand_filename(path, getuid());
if (*expanded == '/')
return expanded;
if (getcwd(cwd, sizeof(cwd)) == NULL)
fatal("%s: getcwd: %s", __func__, strerror(errno));
xasprintf(&ret, "%s/%s", cwd, expanded);
free(expanded);
return ret;
}
static void
add_listen_addr(ServerOptions *options, char *addr, int 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, int 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, "%d", 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;
}
struct connection_info *
get_connection_info(int populate, int use_dns)
{
static struct connection_info ci;
if (!populate)
return &ci;
ci.host = get_canonical_hostname(use_dns);
ci.address = get_remote_ipaddr();
ci.laddress = get_local_ipaddr(packet_get_connection_in());
ci.lport = get_local_port();
return &ci;
}
/*
* 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;
struct passwd *pw;
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_pattern_list(grps) != 1) {
debug("user %.100s does not match group list %.100s at line %d",
user, grps, line);
} else {
debug("user %.100s matched group list %.100s at line %d", user,
grps, line);
result = 1;
}
out:
ga_free();
return result;
}
/*
* All of the attributes on a single Match line are ANDed together, so we need
* to check every attribute and set the result to zero if any attribute does
* not match.
*/
static int
match_cfg_line(char **condition, int line, struct connection_info *ci)
{
int result = 1, attributes = 0, port;
char *arg, *attrib, *cp = *condition;
size_t len;
if (ci == NULL)
debug3("checking syntax for 'Match %s'", cp);
else
debug3("checking match for '%s' user %s host %s addr %s "
"laddr %s lport %d", cp, ci->user ? ci->user : "(null)",
ci->host ? ci->host : "(null)",
ci->address ? ci->address : "(null)",
ci->laddress ? ci->laddress : "(null)", ci->lport);
while ((attrib = strdelim(&cp)) && *attrib != '\0') {
attributes++;
if (strcasecmp(attrib, "all") == 0) {
if (attributes != 1 ||
((arg = strdelim(&cp)) != NULL && *arg != '\0')) {
error("'all' cannot be combined with other "
"Match attributes");
return -1;
}
*condition = cp;
return 1;
}
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 (ci == NULL || ci->user == NULL) {
result = 0;
continue;
}
if (match_pattern_list(ci->user, arg, len, 0) != 1)
result = 0;
else
debug("user %.100s matched 'User %.100s' at "
"line %d", ci->user, arg, line);
} else if (strcasecmp(attrib, "group") == 0) {
if (ci == NULL || ci->user == NULL) {
result = 0;
continue;
}
switch (match_cfg_line_group(arg, line, ci->user)) {
case -1:
return -1;
case 0:
result = 0;
}
} else if (strcasecmp(attrib, "host") == 0) {
if (ci == NULL || ci->host == NULL) {
result = 0;
continue;
}
if (match_hostname(ci->host, arg, len) != 1)
result = 0;
else
debug("connection from %.100s matched 'Host "
"%.100s' at line %d", ci->host, arg, line);
} else if (strcasecmp(attrib, "address") == 0) {
if (ci == NULL || ci->address == NULL) {
result = 0;
continue;
}
switch (addr_match_list(ci->address, arg)) {
case 1:
debug("connection from %.100s matched 'Address "
"%.100s' at line %d", ci->address, arg, line);
break;
case 0:
case -1:
result = 0;
break;
case -2:
return -1;
}
} else if (strcasecmp(attrib, "localaddress") == 0){
if (ci == NULL || ci->laddress == NULL) {
result = 0;
continue;
}
switch (addr_match_list(ci->laddress, arg)) {
case 1:
debug("connection from %.100s matched "
"'LocalAddress %.100s' at line %d",
ci->laddress, arg, line);
break;
case 0:
case -1:
result = 0;
break;
case -2:
return -1;
}
} else if (strcasecmp(attrib, "localport") == 0) {
if ((port = a2port(arg)) == -1) {
error("Invalid LocalPort '%s' on Match line",
arg);
return -1;
}
if (ci == NULL || ci->lport == 0) {
result = 0;
continue;
}
/* TODO support port lists */
if (port == ci->lport)
debug("connection from %.100s matched "
"'LocalPort %d' at line %d",
ci->laddress, port, line);
else
result = 0;
} else {
error("Unsupported Match attribute %s", attrib);
return -1;
}
}
if (attributes == 0) {
error("One or more attributes required for Match");
return -1;
}
if (ci != NULL)
debug3("match %sfound", result ? "" : "not ");
*condition = cp;
return result;
}
#define WHITESPACE " \t\r\n"
/* Multistate option parsing */
struct multistate {
char *key;
int value;
};
static const struct multistate multistate_addressfamily[] = {
{ "inet", AF_INET },
{ "inet6", AF_INET6 },
{ "any", AF_UNSPEC },
{ NULL, -1 }
};
static const struct multistate multistate_permitrootlogin[] = {
{ "without-password", PERMIT_NO_PASSWD },
{ "forced-commands-only", PERMIT_FORCED_ONLY },
{ "yes", PERMIT_YES },
{ "no", PERMIT_NO },
{ NULL, -1 }
};
static const struct multistate multistate_compression[] = {
{ "delayed", COMP_DELAYED },
{ "yes", COMP_ZLIB },
{ "no", COMP_NONE },
{ NULL, -1 }
};
static const struct multistate multistate_gatewayports[] = {
{ "clientspecified", 2 },
{ "yes", 1 },
{ "no", 0 },
{ NULL, -1 }
};
static const struct multistate multistate_privsep[] = {
{ "yes", PRIVSEP_NOSANDBOX },
{ "sandbox", PRIVSEP_ON },
{ "nosandbox", PRIVSEP_NOSANDBOX },
{ "no", PRIVSEP_OFF },
{ NULL, -1 }
};
static const struct multistate multistate_tcpfwd[] = {
{ "yes", FORWARD_ALLOW },
{ "all", FORWARD_ALLOW },
{ "no", FORWARD_DENY },
{ "remote", FORWARD_REMOTE },
{ "local", FORWARD_LOCAL },
{ NULL, -1 }
};
int
process_server_config_line(ServerOptions *options, char *line,
const char *filename, int linenum, int *activep,
struct connection_info *connectinfo)
{
char *cp, **charptr, *arg, *p;
int cmdline = 0, *intptr, value, value2, n, port;
SyslogFacility *log_facility_ptr;
LogLevel *log_level_ptr;
ServerOpCodes opcode;
u_int i, flags = 0;
size_t len;
long long val64;
const struct multistate *multistate_ptr;
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 (connectinfo == 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:
intptr = &options->address_family;
multistate_ptr = multistate_addressfamily;
if (options->listen_addrs != NULL)
fatal("%s line %d: address family must be specified "
"before ListenAddress.", filename, linenum);
parse_multistate:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing argument.",
filename, linenum);
value = -1;
for (i = 0; multistate_ptr[i].key != NULL; i++) {
if (strcasecmp(arg, multistate_ptr[i].key) == 0) {
value = multistate_ptr[i].value;
break;
}
}
if (value == -1)
fatal("%s line %d: unsupported option \"%s\".",
filename, linenum, arg);
if (*activep && *intptr == -1)
*intptr = value;
break;
case 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 = derelativise_path(arg);
/* increase optional counter */
if (intptr != NULL)
*intptr = *intptr + 1;
}
break;
case sHostKeyAgent:
charptr = &options->host_key_agent;
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing socket name.",
filename, linenum);
if (*activep && *charptr == NULL)
*charptr = !strcmp(arg, SSH_AUTHSOCKET_ENV_NAME) ?
xstrdup(arg) : derelativise_path(arg);
break;
case sHostCertificate:
intptr = &options->num_host_cert_files;
if (*intptr >= MAX_HOSTKEYS)
fatal("%s line %d: too many host certificates "
"specified (max %d).", filename, linenum,
MAX_HOSTCERTS);
charptr = &options->host_cert_files[*intptr];
goto parse_filename;
break;
case sPidFile:
charptr = &options->pid_file;
goto parse_filename;
case sPermitRootLogin:
intptr = &options->permit_root_login;
multistate_ptr = multistate_permitrootlogin;
goto parse_multistate;
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 sPermitTTY:
intptr = &options->permit_tty;
goto parse_flag;
case sPermitUserRC:
intptr = &options->permit_user_rc;
goto parse_flag;
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;
multistate_ptr = multistate_compression;
goto parse_multistate;
case sRekeyLimit:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename,
linenum);
if (strcmp(arg, "default") == 0) {
val64 = 0;
} else {
if (scan_scaled(arg, &val64) == -1)
fatal("%.200s line %d: Bad number '%s': %s",
filename, linenum, arg, strerror(errno));
/* check for too-large or too-small limits */
if (val64 > UINT_MAX)
fatal("%.200s line %d: RekeyLimit too large",
filename, linenum);
if (val64 != 0 && val64 < 16)
fatal("%.200s line %d: RekeyLimit too small",
filename, linenum);
}
if (*activep && options->rekey_limit == -1)
options->rekey_limit = (u_int32_t)val64;
if (cp != NULL) { /* optional rekey interval present */
if (strcmp(cp, "none") == 0) {
(void)strdelim(&cp); /* discard */
break;
}
intptr = &options->rekey_interval;
goto parse_time;
}
break;
case sGatewayPorts:
intptr = &options->gateway_ports;
multistate_ptr = multistate_gatewayports;
goto parse_multistate;
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;
multistate_ptr = multistate_tcpfwd;
goto parse_multistate;
case sAllowAgentForwarding:
intptr = &options->allow_agent_forwarding;
goto parse_flag;
case sUsePrivilegeSeparation:
intptr = &use_privsep;
multistate_ptr = multistate_privsep;
goto parse_multistate;
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);
if (!*activep)
continue;
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);
if (!*activep)
continue;
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);
if (!*activep)
continue;
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);
if (!*activep)
continue;
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 sKexAlgorithms:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing argument.",
filename, linenum);
if (!kex_names_valid(arg))
fatal("%s line %d: Bad SSH2 KexAlgorithms '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (options->kex_algorithms == NULL)
options->kex_algorithms = 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 sMaxSessions:
intptr = &options->max_sessions;
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:
if (*activep && options->num_authkeys_files == 0) {
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (options->num_authkeys_files >=
MAX_AUTHKEYS_FILES)
fatal("%s line %d: "
"too many authorized keys files.",
filename, linenum);
options->authorized_keys_files[
options->num_authkeys_files++] =
tilde_expand_filename(arg, getuid());
}
}
return 0;
case sAuthorizedPrincipalsFile:
charptr = &options->authorized_principals_file;
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 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)
continue;
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 = -1;
for (i = 0; tunmode_desc[i].val != -1; i++)
if (strcmp(tunmode_desc[i].text, arg) == 0) {
value = tunmode_desc[i].val;
break;
}
if (value == -1)
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, connectinfo);
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 (strcmp(arg, "none") == 0) {
if (*activep && n == -1) {
options->num_permitted_opens = 1;
channel_disable_adm_local_opens();
}
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 = permitopen_port(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 sTrustedUserCAKeys:
charptr = &options->trusted_user_ca_keys;
goto parse_filename;
case sRevokedKeys:
charptr = &options->revoked_keys_file;
goto parse_filename;
case sIPQoS:
arg = strdelim(&cp);
if ((value = parse_ipqos(arg)) == -1)
fatal("%s line %d: Bad IPQoS value: %s",
filename, linenum, arg);
arg = strdelim(&cp);
if (arg == NULL)
value2 = value;
else if ((value2 = parse_ipqos(arg)) == -1)
fatal("%s line %d: Bad IPQoS value: %s",
filename, linenum, arg);
if (*activep) {
options->ip_qos_interactive = value;
options->ip_qos_bulk = value2;
}
break;
case sVersionAddendum:
if (cp == NULL)
fatal("%.200s line %d: Missing argument.", filename,
linenum);
len = strspn(cp, WHITESPACE);
if (*activep && options->version_addendum == NULL) {
if (strcasecmp(cp + len, "none") == 0)
options->version_addendum = xstrdup("");
else if (strchr(cp + len, '\r') != NULL)
fatal("%.200s line %d: Invalid argument",
filename, linenum);
else
options->version_addendum = xstrdup(cp + len);
}
return 0;
case sAuthorizedKeysCommand:
len = strspn(cp, WHITESPACE);
if (*activep && options->authorized_keys_command == NULL) {
if (cp[len] != '/' && strcasecmp(cp + len, "none") != 0)
fatal("%.200s line %d: AuthorizedKeysCommand "
"must be an absolute path",
filename, linenum);
options->authorized_keys_command = xstrdup(cp + len);
}
return 0;
case sAuthorizedKeysCommandUser:
charptr = &options->authorized_keys_command_user;
arg = strdelim(&cp);
if (*activep && *charptr == NULL)
*charptr = xstrdup(arg);
break;
case sAuthenticationMethods:
if (*activep && options->num_auth_methods == 0) {
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (options->num_auth_methods >=
MAX_AUTH_METHODS)
fatal("%s line %d: "
"too many authentication methods.",
filename, linenum);
if (auth2_methods_valid(arg, 0) != 0)
fatal("%s line %d: invalid "
"authentication method list.",
filename, linenum);
options->auth_methods[
options->num_auth_methods++] = xstrdup(arg);
}
}
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[4096], *cp;
FILE *f;
int lineno = 0;
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)) {
lineno++;
if (strlen(line) == sizeof(line) - 1)
fatal("%s line %d too long", filename, lineno);
/*
* 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,
struct connection_info *connectinfo)
{
ServerOptions mo;
initialize_server_options(&mo);
parse_server_config(&mo, "reprocess config", &cfg, connectinfo);
copy_set_server_options(options, &mo, 0);
}
int parse_server_match_testspec(struct connection_info *ci, char *spec)
{
char *p;
while ((p = strsep(&spec, ",")) && *p != '\0') {
if (strncmp(p, "addr=", 5) == 0) {
ci->address = xstrdup(p + 5);
} else if (strncmp(p, "host=", 5) == 0) {
ci->host = xstrdup(p + 5);
} else if (strncmp(p, "user=", 5) == 0) {
ci->user = xstrdup(p + 5);
} else if (strncmp(p, "laddr=", 6) == 0) {
ci->laddress = xstrdup(p + 6);
} else if (strncmp(p, "lport=", 6) == 0) {
ci->lport = a2port(p + 6);
if (ci->lport == -1) {
fprintf(stderr, "Invalid port '%s' in test mode"
" specification %s\n", p+6, p);
return -1;
}
} else {
fprintf(stderr, "Invalid test mode specification %s\n",
p);
return -1;
}
}
return 0;
}
/*
* returns 1 for a complete spec, 0 for partial spec and -1 for an
* empty spec.
*/
int server_match_spec_complete(struct connection_info *ci)
{
if (ci->user && ci->host && ci->address)
return 1; /* complete */
if (!ci->user && !ci->host && !ci->address)
return -1; /* empty */
return 0; /* partial */
}
/*
* Copy any supported values that are set.
*
* If the preauth flag is set, we do not bother copying 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)
{
#define M_CP_INTOPT(n) do {\
if (src->n != -1) \
dst->n = src->n; \
} while (0)
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(hostbased_uses_name_from_packet_only);
M_CP_INTOPT(kbd_interactive_authentication);
M_CP_INTOPT(permit_root_login);
M_CP_INTOPT(permit_empty_passwd);
M_CP_INTOPT(allow_tcp_forwarding);
M_CP_INTOPT(allow_agent_forwarding);
M_CP_INTOPT(permit_tun);
M_CP_INTOPT(gateway_ports);
M_CP_INTOPT(x11_display_offset);
M_CP_INTOPT(x11_forwarding);
M_CP_INTOPT(x11_use_localhost);
M_CP_INTOPT(permit_tty);
M_CP_INTOPT(permit_user_rc);
M_CP_INTOPT(max_sessions);
M_CP_INTOPT(max_authtries);
M_CP_INTOPT(ip_qos_interactive);
M_CP_INTOPT(ip_qos_bulk);
M_CP_INTOPT(rekey_limit);
M_CP_INTOPT(rekey_interval);
/* M_CP_STROPT and M_CP_STRARRAYOPT should not appear before here */
#define M_CP_STROPT(n) do {\
if (src->n != NULL && dst->n != src->n) { \
free(dst->n); \
dst->n = src->n; \
} \
} while(0)
#define M_CP_STRARRAYOPT(n, num_n) do {\
if (src->num_n != 0) { \
for (dst->num_n = 0; dst->num_n < src->num_n; dst->num_n++) \
dst->n[dst->num_n] = xstrdup(src->n[dst->num_n]); \
} \
} while(0)
/* See comment in servconf.h */
COPY_MATCH_STRING_OPTS();
/*
* The only things that should be below this point are string options
* which are only used after authentication.
*/
if (preauth)
return;
M_CP_STROPT(adm_forced_command);
M_CP_STROPT(chroot_directory);
}
#undef M_CP_INTOPT
#undef M_CP_STROPT
#undef M_CP_STRARRAYOPT
void
parse_server_config(ServerOptions *options, const char *filename, Buffer *conf,
struct connection_info *connectinfo)
{
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 = connectinfo ? 0 : 1;
linenum = 1;
while ((cp = strsep(&cbuf, "\n")) != NULL) {
if (process_server_config_line(options, cp, filename,
linenum++, &active, connectinfo) != 0)
bad_options++;
}
free(obuf);
if (bad_options > 0)
fatal("%s: terminating, %d bad configuration options",
filename, bad_options);
}
static const char *
fmt_multistate_int(int val, const struct multistate *m)
{
u_int i;
for (i = 0; m[i].key != NULL; i++) {
if (m[i].value == val)
return m[i].key;
}
return "UNKNOWN";
}
static const char *
fmt_intarg(ServerOpCodes code, int val)
{
if (val == -1)
return "unset";
switch (code) {
case sAddressFamily:
return fmt_multistate_int(val, multistate_addressfamily);
case sPermitRootLogin:
return fmt_multistate_int(val, multistate_permitrootlogin);
case sGatewayPorts:
return fmt_multistate_int(val, multistate_gatewayports);
case sCompression:
return fmt_multistate_int(val, multistate_compression);
case sUsePrivilegeSeparation:
return fmt_multistate_int(val, multistate_privsep);
case sAllowTcpForwarding:
return fmt_multistate_int(val, multistate_tcpfwd);
case sProtocol:
switch (val) {
case SSH_PROTO_1:
return "1";
case SSH_PROTO_2:
return "2";
case (SSH_PROTO_1|SSH_PROTO_2):
return "2,1";
default:
return "UNKNOWN";
}
default:
switch (val) {
case 0:
return "no";
case 1:
return "yes";
default:
return "UNKNOWN";
}
}
}
static const char *
lookup_opcode_name(ServerOpCodes code)
{
u_int i;
for (i = 0; keywords[i].name != NULL; i++)
if (keywords[i].opcode == code)
return(keywords[i].name);
return "UNKNOWN";
}
static void
dump_cfg_int(ServerOpCodes code, int val)
{
printf("%s %d\n", lookup_opcode_name(code), val);
}
static void
dump_cfg_fmtint(ServerOpCodes code, int val)
{
printf("%s %s\n", lookup_opcode_name(code), fmt_intarg(code, val));
}
static void
dump_cfg_string(ServerOpCodes code, const char *val)
{
if (val == NULL)
return;
printf("%s %s\n", lookup_opcode_name(code), val);
}
static void
dump_cfg_strarray(ServerOpCodes code, u_int count, char **vals)
{
u_int i;
for (i = 0; i < count; i++)
printf("%s %s\n", lookup_opcode_name(code), vals[i]);
}
static void
dump_cfg_strarray_oneline(ServerOpCodes code, u_int count, char **vals)
{
u_int i;
printf("%s", lookup_opcode_name(code));
for (i = 0; i < count; i++)
printf(" %s", vals[i]);
printf("\n");
}
void
dump_config(ServerOptions *o)
{
u_int i;
int ret;
struct addrinfo *ai;
char addr[NI_MAXHOST], port[NI_MAXSERV], *s = NULL;
/* these are usually at the top of the config */
for (i = 0; i < o->num_ports; i++)
printf("port %d\n", o->ports[i]);
dump_cfg_fmtint(sProtocol, o->protocol);
dump_cfg_fmtint(sAddressFamily, o->address_family);
/* ListenAddress must be after Port */
for (ai = o->listen_addrs; ai; ai = ai->ai_next) {
if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen, addr,
sizeof(addr), port, sizeof(port),
NI_NUMERICHOST|NI_NUMERICSERV)) != 0) {
error("getnameinfo failed: %.100s",
(ret != EAI_SYSTEM) ? gai_strerror(ret) :
strerror(errno));
} else {
if (ai->ai_family == AF_INET6)
printf("listenaddress [%s]:%s\n", addr, port);
else
printf("listenaddress %s:%s\n", addr, port);
}
}
/* integer arguments */
#ifdef USE_PAM
dump_cfg_int(sUsePAM, o->use_pam);
#endif
dump_cfg_int(sServerKeyBits, o->server_key_bits);
dump_cfg_int(sLoginGraceTime, o->login_grace_time);
dump_cfg_int(sKeyRegenerationTime, o->key_regeneration_time);
dump_cfg_int(sX11DisplayOffset, o->x11_display_offset);
dump_cfg_int(sMaxAuthTries, o->max_authtries);
dump_cfg_int(sMaxSessions, o->max_sessions);
dump_cfg_int(sClientAliveInterval, o->client_alive_interval);
dump_cfg_int(sClientAliveCountMax, o->client_alive_count_max);
/* formatted integer arguments */
dump_cfg_fmtint(sPermitRootLogin, o->permit_root_login);
dump_cfg_fmtint(sIgnoreRhosts, o->ignore_rhosts);
dump_cfg_fmtint(sIgnoreUserKnownHosts, o->ignore_user_known_hosts);
dump_cfg_fmtint(sRhostsRSAAuthentication, o->rhosts_rsa_authentication);
dump_cfg_fmtint(sHostbasedAuthentication, o->hostbased_authentication);
dump_cfg_fmtint(sHostbasedUsesNameFromPacketOnly,
o->hostbased_uses_name_from_packet_only);
dump_cfg_fmtint(sRSAAuthentication, o->rsa_authentication);
dump_cfg_fmtint(sPubkeyAuthentication, o->pubkey_authentication);
#ifdef KRB5
dump_cfg_fmtint(sKerberosAuthentication, o->kerberos_authentication);
dump_cfg_fmtint(sKerberosOrLocalPasswd, o->kerberos_or_local_passwd);
dump_cfg_fmtint(sKerberosTicketCleanup, o->kerberos_ticket_cleanup);
# ifdef USE_AFS
dump_cfg_fmtint(sKerberosGetAFSToken, o->kerberos_get_afs_token);
# endif
#endif
#ifdef GSSAPI
dump_cfg_fmtint(sGssAuthentication, o->gss_authentication);
dump_cfg_fmtint(sGssCleanupCreds, o->gss_cleanup_creds);
#endif
dump_cfg_fmtint(sPasswordAuthentication, o->password_authentication);
dump_cfg_fmtint(sKbdInteractiveAuthentication,
o->kbd_interactive_authentication);
dump_cfg_fmtint(sChallengeResponseAuthentication,
o->challenge_response_authentication);
dump_cfg_fmtint(sPrintMotd, o->print_motd);
dump_cfg_fmtint(sPrintLastLog, o->print_lastlog);
dump_cfg_fmtint(sX11Forwarding, o->x11_forwarding);
dump_cfg_fmtint(sX11UseLocalhost, o->x11_use_localhost);
dump_cfg_fmtint(sPermitTTY, o->permit_tty);
dump_cfg_fmtint(sPermitUserRC, o->permit_user_rc);
dump_cfg_fmtint(sStrictModes, o->strict_modes);
dump_cfg_fmtint(sTCPKeepAlive, o->tcp_keep_alive);
dump_cfg_fmtint(sEmptyPasswd, o->permit_empty_passwd);
dump_cfg_fmtint(sPermitUserEnvironment, o->permit_user_env);
dump_cfg_fmtint(sUseLogin, o->use_login);
dump_cfg_fmtint(sCompression, o->compression);
dump_cfg_fmtint(sGatewayPorts, o->gateway_ports);
dump_cfg_fmtint(sUseDNS, o->use_dns);
dump_cfg_fmtint(sAllowTcpForwarding, o->allow_tcp_forwarding);
dump_cfg_fmtint(sUsePrivilegeSeparation, use_privsep);
/* string arguments */
dump_cfg_string(sPidFile, o->pid_file);
dump_cfg_string(sXAuthLocation, o->xauth_location);
dump_cfg_string(sCiphers, o->ciphers ? o->ciphers :
cipher_alg_list(',', 0));
dump_cfg_string(sMacs, o->macs ? o->macs : mac_alg_list(','));
dump_cfg_string(sBanner, o->banner);
dump_cfg_string(sForceCommand, o->adm_forced_command);
dump_cfg_string(sChrootDirectory, o->chroot_directory);
dump_cfg_string(sTrustedUserCAKeys, o->trusted_user_ca_keys);
dump_cfg_string(sRevokedKeys, o->revoked_keys_file);
dump_cfg_string(sAuthorizedPrincipalsFile,
o->authorized_principals_file);
dump_cfg_string(sVersionAddendum, o->version_addendum);
dump_cfg_string(sAuthorizedKeysCommand, o->authorized_keys_command);
dump_cfg_string(sAuthorizedKeysCommandUser, o->authorized_keys_command_user);
dump_cfg_string(sHostKeyAgent, o->host_key_agent);
dump_cfg_string(sKexAlgorithms, o->kex_algorithms ? o->kex_algorithms :
kex_alg_list(','));
/* string arguments requiring a lookup */
dump_cfg_string(sLogLevel, log_level_name(o->log_level));
dump_cfg_string(sLogFacility, log_facility_name(o->log_facility));
/* string array arguments */
dump_cfg_strarray_oneline(sAuthorizedKeysFile, o->num_authkeys_files,
o->authorized_keys_files);
dump_cfg_strarray(sHostKeyFile, o->num_host_key_files,
o->host_key_files);
dump_cfg_strarray(sHostKeyFile, o->num_host_cert_files,
o->host_cert_files);
dump_cfg_strarray(sAllowUsers, o->num_allow_users, o->allow_users);
dump_cfg_strarray(sDenyUsers, o->num_deny_users, o->deny_users);
dump_cfg_strarray(sAllowGroups, o->num_allow_groups, o->allow_groups);
dump_cfg_strarray(sDenyGroups, o->num_deny_groups, o->deny_groups);
dump_cfg_strarray(sAcceptEnv, o->num_accept_env, o->accept_env);
dump_cfg_strarray_oneline(sAuthenticationMethods,
o->num_auth_methods, o->auth_methods);
/* other arguments */
for (i = 0; i < o->num_subsystems; i++)
printf("subsystem %s %s\n", o->subsystem_name[i],
o->subsystem_args[i]);
printf("maxstartups %d:%d:%d\n", o->max_startups_begin,
o->max_startups_rate, o->max_startups);
for (i = 0; tunmode_desc[i].val != -1; i++)
if (tunmode_desc[i].val == o->permit_tun) {
s = tunmode_desc[i].text;
break;
}
dump_cfg_string(sPermitTunnel, s);
printf("ipqos %s ", iptos2str(o->ip_qos_interactive));
printf("%s\n", iptos2str(o->ip_qos_bulk));
printf("rekeylimit %lld %d\n", (long long)o->rekey_limit,
o->rekey_interval);
channel_print_adm_permitted_opens();
}