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/*
*
* servconf.c
*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
*
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
*
* Created: Mon Aug 21 15:48:58 1995 ylo
*
*/
#include "includes.h"
RCSID("$Id: servconf.c,v 1.17 2000/05/30 03:44:53 damien Exp $");
#include "ssh.h"
#include "servconf.h"
#include "xmalloc.h"
#include "compat.h"
/* add listen address */
void add_listen_addr(ServerOptions *options, char *addr);
/* Initializes the server options to their default values. */
void
initialize_server_options(ServerOptions *options)
{
memset(options, 0, sizeof(*options));
options->num_ports = 0;
options->ports_from_cmdline = 0;
options->listen_addrs = NULL;
options->host_key_file = NULL;
options->host_dsa_key_file = NULL;
options->pid_file = NULL;
options->server_key_bits = -1;
options->login_grace_time = -1;
options->key_regeneration_time = -1;
options->permit_root_login = -1;
options->ignore_rhosts = -1;
options->ignore_user_known_hosts = -1;
options->print_motd = -1;
options->check_mail = -1;
options->x11_forwarding = -1;
options->x11_display_offset = -1;
options->strict_modes = -1;
options->keepalives = -1;
options->log_facility = (SyslogFacility) - 1;
options->log_level = (LogLevel) - 1;
options->rhosts_authentication = -1;
options->rhosts_rsa_authentication = -1;
options->rsa_authentication = -1;
options->dsa_authentication = -1;
#ifdef KRB4
options->kerberos_authentication = -1;
options->kerberos_or_local_passwd = -1;
options->kerberos_ticket_cleanup = -1;
#endif
#ifdef AFS
options->kerberos_tgt_passing = -1;
options->afs_token_passing = -1;
#endif
options->password_authentication = -1;
#ifdef SKEY
options->skey_authentication = -1;
#endif
options->permit_empty_passwd = -1;
options->use_login = -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->protocol = SSH_PROTO_UNKNOWN;
options->gateway_ports = -1;
}
void
fill_default_server_options(ServerOptions *options)
{
if (options->num_ports == 0)
options->ports[options->num_ports++] = SSH_DEFAULT_PORT;
if (options->listen_addrs == NULL)
add_listen_addr(options, NULL);
if (options->host_key_file == NULL)
options->host_key_file = HOST_KEY_FILE;
if (options->host_dsa_key_file == NULL)
options->host_dsa_key_file = HOST_DSA_KEY_FILE;
if (options->pid_file == NULL)
options->pid_file = 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 = 600;
if (options->key_regeneration_time == -1)
options->key_regeneration_time = 3600;
if (options->permit_root_login == -1)
options->permit_root_login = 1; /* 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->check_mail == -1)
options->check_mail = 0;
if (options->print_motd == -1)
options->print_motd = 1;
if (options->x11_forwarding == -1)
options->x11_forwarding = 0;
if (options->x11_display_offset == -1)
options->x11_display_offset = 10;
if (options->strict_modes == -1)
options->strict_modes = 1;
if (options->keepalives == -1)
options->keepalives = 1;
if (options->log_facility == (SyslogFacility) (-1))
options->log_facility = SYSLOG_FACILITY_AUTH;
if (options->log_level == (LogLevel) (-1))
options->log_level = SYSLOG_LEVEL_INFO;
if (options->rhosts_authentication == -1)
options->rhosts_authentication = 0;
if (options->rhosts_rsa_authentication == -1)
options->rhosts_rsa_authentication = 0;
if (options->rsa_authentication == -1)
options->rsa_authentication = 1;
if (options->dsa_authentication == -1)
options->dsa_authentication = 1;
#ifdef KRB4
if (options->kerberos_authentication == -1)
options->kerberos_authentication = (access(KEYFILE, R_OK) == 0);
if (options->kerberos_or_local_passwd == -1)
options->kerberos_or_local_passwd = 1;
if (options->kerberos_ticket_cleanup == -1)
options->kerberos_ticket_cleanup = 1;
#endif /* KRB4 */
#ifdef AFS
if (options->kerberos_tgt_passing == -1)
options->kerberos_tgt_passing = 0;
if (options->afs_token_passing == -1)
options->afs_token_passing = k_hasafs();
#endif /* AFS */
if (options->password_authentication == -1)
options->password_authentication = 1;
#ifdef SKEY
if (options->skey_authentication == -1)
options->skey_authentication = 1;
#endif
if (options->permit_empty_passwd == -1)
options->permit_empty_passwd = 0;
if (options->use_login == -1)
options->use_login = 0;
if (options->protocol == SSH_PROTO_UNKNOWN)
options->protocol = SSH_PROTO_1|SSH_PROTO_2;
if (options->gateway_ports == -1)
options->gateway_ports = 0;
}
#define WHITESPACE " \t\r\n"
/* Keyword tokens. */
typedef enum {
sBadOption, /* == unknown option */
sPort, sHostKeyFile, sServerKeyBits, sLoginGraceTime, sKeyRegenerationTime,
sPermitRootLogin, sLogFacility, sLogLevel,
sRhostsAuthentication, sRhostsRSAAuthentication, sRSAAuthentication,
#ifdef KRB4
sKerberosAuthentication, sKerberosOrLocalPasswd, sKerberosTicketCleanup,
#endif
#ifdef AFS
sKerberosTgtPassing, sAFSTokenPassing,
#endif
#ifdef SKEY
sSkeyAuthentication,
#endif
sPasswordAuthentication, sListenAddress,
sPrintMotd, sIgnoreRhosts, sX11Forwarding, sX11DisplayOffset,
sStrictModes, sEmptyPasswd, sRandomSeedFile, sKeepAlives, sCheckMail,
sUseLogin, sAllowUsers, sDenyUsers, sAllowGroups, sDenyGroups,
sIgnoreUserKnownHosts, sHostDSAKeyFile, sCiphers, sProtocol, sPidFile,
sGatewayPorts, sDSAAuthentication
} ServerOpCodes;
/* Textual representation of the tokens. */
static struct {
const char *name;
ServerOpCodes opcode;
} keywords[] = {
{ "port", sPort },
{ "hostkey", sHostKeyFile },
{ "hostdsakey", sHostDSAKeyFile },
{ "pidfile", sPidFile },
{ "serverkeybits", sServerKeyBits },
{ "logingracetime", sLoginGraceTime },
{ "keyregenerationinterval", sKeyRegenerationTime },
{ "permitrootlogin", sPermitRootLogin },
{ "syslogfacility", sLogFacility },
{ "loglevel", sLogLevel },
{ "rhostsauthentication", sRhostsAuthentication },
{ "rhostsrsaauthentication", sRhostsRSAAuthentication },
{ "rsaauthentication", sRSAAuthentication },
{ "dsaauthentication", sDSAAuthentication },
#ifdef KRB4
{ "kerberosauthentication", sKerberosAuthentication },
{ "kerberosorlocalpasswd", sKerberosOrLocalPasswd },
{ "kerberosticketcleanup", sKerberosTicketCleanup },
#endif
#ifdef AFS
{ "kerberostgtpassing", sKerberosTgtPassing },
{ "afstokenpassing", sAFSTokenPassing },
#endif
{ "passwordauthentication", sPasswordAuthentication },
#ifdef SKEY
{ "skeyauthentication", sSkeyAuthentication },
#endif
{ "checkmail", sCheckMail },
{ "listenaddress", sListenAddress },
{ "printmotd", sPrintMotd },
{ "ignorerhosts", sIgnoreRhosts },
{ "ignoreuserknownhosts", sIgnoreUserKnownHosts },
{ "x11forwarding", sX11Forwarding },
{ "x11displayoffset", sX11DisplayOffset },
{ "strictmodes", sStrictModes },
{ "permitemptypasswords", sEmptyPasswd },
{ "uselogin", sUseLogin },
{ "randomseed", sRandomSeedFile },
{ "keepalive", sKeepAlives },
{ "allowusers", sAllowUsers },
{ "denyusers", sDenyUsers },
{ "allowgroups", sAllowGroups },
{ "denygroups", sDenyGroups },
{ "ciphers", sCiphers },
{ "protocol", sProtocol },
{ "gatewayports", sGatewayPorts },
{ NULL, 0 }
};
/*
* Returns the number of the token pointed to by cp of length len. Never
* returns if the token is not known.
*/
static ServerOpCodes
parse_token(const char *cp, const char *filename,
int linenum)
{
unsigned int i;
for (i = 0; keywords[i].name; i++)
if (strcasecmp(cp, keywords[i].name) == 0)
return keywords[i].opcode;
fprintf(stderr, "%s: line %d: Bad configuration option: %s\n",
filename, linenum, cp);
return sBadOption;
}
/*
* add listen address
*/
void
add_listen_addr(ServerOptions *options, char *addr)
{
extern int IPv4or6;
struct addrinfo hints, *ai, *aitop;
char strport[NI_MAXSERV];
int gaierr;
int i;
if (options->num_ports == 0)
options->ports[options->num_ports++] = SSH_DEFAULT_PORT;
for (i = 0; i < options->num_ports; i++) {
memset(&hints, 0, sizeof(hints));
hints.ai_family = IPv4or6;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = (addr == NULL) ? AI_PASSIVE : 0;
snprintf(strport, sizeof strport, "%d", options->ports[i]);
if ((gaierr = getaddrinfo(addr, strport, &hints, &aitop)) != 0)
fatal("bad addr or host: %s (%s)\n",
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;
}
}
/* Reads the server configuration file. */
void
read_server_config(ServerOptions *options, const char *filename)
{
FILE *f;
char line[1024];
char *cp, **charptr;
int linenum, *intptr, value;
int bad_options = 0;
ServerOpCodes opcode;
f = fopen(filename, "r");
if (!f) {
perror(filename);
exit(1);
}
linenum = 0;
while (fgets(line, sizeof(line), f)) {
linenum++;
cp = line + strspn(line, WHITESPACE);
if (!*cp || *cp == '#')
continue;
cp = strtok(cp, WHITESPACE);
opcode = parse_token(cp, filename, linenum);
switch (opcode) {
case sBadOption:
bad_options++;
continue;
case sPort:
/* ignore ports from configfile if cmdline specifies ports */
if (options->ports_from_cmdline)
continue;
if (options->listen_addrs != NULL)
fatal("%s line %d: ports must be specified before "
"ListenAdress.\n", filename, linenum);
if (options->num_ports >= MAX_PORTS)
fatal("%s line %d: too many ports.\n",
filename, linenum);
cp = strtok(NULL, WHITESPACE);
if (!cp)
fatal("%s line %d: missing port number.\n",
filename, linenum);
options->ports[options->num_ports++] = atoi(cp);
break;
case sServerKeyBits:
intptr = &options->server_key_bits;
parse_int:
cp = strtok(NULL, WHITESPACE);
if (!cp) {
fprintf(stderr, "%s line %d: missing integer value.\n",
filename, linenum);
exit(1);
}
value = atoi(cp);
if (*intptr == -1)
*intptr = value;
break;
case sLoginGraceTime:
intptr = &options->login_grace_time;
goto parse_int;
case sKeyRegenerationTime:
intptr = &options->key_regeneration_time;
goto parse_int;
case sListenAddress:
cp = strtok(NULL, WHITESPACE);
if (!cp)
fatal("%s line %d: missing inet addr.\n",
filename, linenum);
add_listen_addr(options, cp);
break;
case sHostKeyFile:
case sHostDSAKeyFile:
charptr = (opcode == sHostKeyFile ) ?
&options->host_key_file : &options->host_dsa_key_file;
cp = strtok(NULL, WHITESPACE);
if (!cp) {
fprintf(stderr, "%s line %d: missing file name.\n",
filename, linenum);
exit(1);
}
if (*charptr == NULL)
*charptr = tilde_expand_filename(cp, getuid());
break;
case sPidFile:
charptr = &options->pid_file;
cp = strtok(NULL, WHITESPACE);
if (!cp) {
fprintf(stderr, "%s line %d: missing file name.\n",
filename, linenum);
exit(1);
}
if (*charptr == NULL)
*charptr = tilde_expand_filename(cp, getuid());
break;
case sRandomSeedFile:
fprintf(stderr, "%s line %d: \"randomseed\" option is obsolete.\n",
filename, linenum);
cp = strtok(NULL, WHITESPACE);
break;
case sPermitRootLogin:
intptr = &options->permit_root_login;
cp = strtok(NULL, WHITESPACE);
if (!cp) {
fprintf(stderr, "%s line %d: missing yes/without-password/no argument.\n",
filename, linenum);
exit(1);
}
if (strcmp(cp, "without-password") == 0)
value = 2;
else if (strcmp(cp, "yes") == 0)
value = 1;
else if (strcmp(cp, "no") == 0)
value = 0;
else {
fprintf(stderr, "%s line %d: Bad yes/without-password/no argument: %s\n",
filename, linenum, cp);
exit(1);
}
if (*intptr == -1)
*intptr = value;
break;
case sIgnoreRhosts:
intptr = &options->ignore_rhosts;
parse_flag:
cp = strtok(NULL, WHITESPACE);
if (!cp) {
fprintf(stderr, "%s line %d: missing yes/no argument.\n",
filename, linenum);
exit(1);
}
if (strcmp(cp, "yes") == 0)
value = 1;
else if (strcmp(cp, "no") == 0)
value = 0;
else {
fprintf(stderr, "%s line %d: Bad yes/no argument: %s\n",
filename, linenum, cp);
exit(1);
}
if (*intptr == -1)
*intptr = value;
break;
case sIgnoreUserKnownHosts:
intptr = &options->ignore_user_known_hosts;
goto parse_flag;
case sRhostsAuthentication:
intptr = &options->rhosts_authentication;
goto parse_flag;
case sRhostsRSAAuthentication:
intptr = &options->rhosts_rsa_authentication;
goto parse_flag;
case sRSAAuthentication:
intptr = &options->rsa_authentication;
goto parse_flag;
case sDSAAuthentication:
intptr = &options->dsa_authentication;
goto parse_flag;
#ifdef KRB4
case sKerberosAuthentication:
intptr = &options->kerberos_authentication;
goto parse_flag;
case sKerberosOrLocalPasswd:
intptr = &options->kerberos_or_local_passwd;
goto parse_flag;
case sKerberosTicketCleanup:
intptr = &options->kerberos_ticket_cleanup;
goto parse_flag;
#endif
#ifdef AFS
case sKerberosTgtPassing:
intptr = &options->kerberos_tgt_passing;
goto parse_flag;
case sAFSTokenPassing:
intptr = &options->afs_token_passing;
goto parse_flag;
#endif
case sPasswordAuthentication:
intptr = &options->password_authentication;
goto parse_flag;
case sCheckMail:
intptr = &options->check_mail;
goto parse_flag;
#ifdef SKEY
case sSkeyAuthentication:
intptr = &options->skey_authentication;
goto parse_flag;
#endif
case sPrintMotd:
intptr = &options->print_motd;
goto parse_flag;
case sX11Forwarding:
intptr = &options->x11_forwarding;
goto parse_flag;
case sX11DisplayOffset:
intptr = &options->x11_display_offset;
goto parse_int;
case sStrictModes:
intptr = &options->strict_modes;
goto parse_flag;
case sKeepAlives:
intptr = &options->keepalives;
goto parse_flag;
case sEmptyPasswd:
intptr = &options->permit_empty_passwd;
goto parse_flag;
case sUseLogin:
intptr = &options->use_login;
goto parse_flag;
case sGatewayPorts:
intptr = &options->gateway_ports;
goto parse_flag;
case sLogFacility:
intptr = (int *) &options->log_facility;
cp = strtok(NULL, WHITESPACE);
value = log_facility_number(cp);
if (value == (SyslogFacility) - 1)
fatal("%.200s line %d: unsupported log facility '%s'\n",
filename, linenum, cp ? cp : "<NONE>");
if (*intptr == -1)
*intptr = (SyslogFacility) value;
break;
case sLogLevel:
intptr = (int *) &options->log_level;
cp = strtok(NULL, WHITESPACE);
value = log_level_number(cp);
if (value == (LogLevel) - 1)
fatal("%.200s line %d: unsupported log level '%s'\n",
filename, linenum, cp ? cp : "<NONE>");
if (*intptr == -1)
*intptr = (LogLevel) value;
break;
case sAllowUsers:
while ((cp = strtok(NULL, WHITESPACE))) {
if (options->num_allow_users >= MAX_ALLOW_USERS)
fatal("%s line %d: too many allow users.\n",
filename, linenum);
options->allow_users[options->num_allow_users++] = xstrdup(cp);
}
break;
case sDenyUsers:
while ((cp = strtok(NULL, WHITESPACE))) {
if (options->num_deny_users >= MAX_DENY_USERS)
fatal( "%s line %d: too many deny users.\n",
filename, linenum);
options->deny_users[options->num_deny_users++] = xstrdup(cp);
}
break;
case sAllowGroups:
while ((cp = strtok(NULL, WHITESPACE))) {
if (options->num_allow_groups >= MAX_ALLOW_GROUPS)
fatal("%s line %d: too many allow groups.\n",
filename, linenum);
options->allow_groups[options->num_allow_groups++] = xstrdup(cp);
}
break;
case sDenyGroups:
while ((cp = strtok(NULL, WHITESPACE))) {
if (options->num_deny_groups >= MAX_DENY_GROUPS)
fatal("%s line %d: too many deny groups.\n",
filename, linenum);
options->deny_groups[options->num_deny_groups++] = xstrdup(cp);
}
break;
case sCiphers:
cp = strtok(NULL, WHITESPACE);
if (!cp)
fatal("%s line %d: Missing argument.", filename, linenum);
if (!ciphers_valid(cp))
fatal("%s line %d: Bad SSH2 cipher spec '%s'.",
filename, linenum, cp ? cp : "<NONE>");
if (options->ciphers == NULL)
options->ciphers = xstrdup(cp);
break;
case sProtocol:
intptr = &options->protocol;
cp = strtok(NULL, WHITESPACE);
if (!cp)
fatal("%s line %d: Missing argument.", filename, linenum);
value = proto_spec(cp);
if (value == SSH_PROTO_UNKNOWN)
fatal("%s line %d: Bad protocol spec '%s'.",
filename, linenum, cp ? cp : "<NONE>");
if (*intptr == SSH_PROTO_UNKNOWN)
*intptr = value;
break;
default:
fprintf(stderr, "%s line %d: Missing handler for opcode %s (%d)\n",
filename, linenum, cp, opcode);
exit(1);
}
if (strtok(NULL, WHITESPACE) != NULL) {
fprintf(stderr, "%s line %d: garbage at end of line.\n",
filename, linenum);
exit(1);
}
}
fclose(f);
if (bad_options > 0) {
fprintf(stderr, "%s: terminating, %d bad configuration options\n",
filename, bad_options);
exit(1);
}
}