openssh/servconf.c

600 lines
15 KiB
C

/*
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 1.3 1999/11/12 00:33:04 damien Exp $");
#include "ssh.h"
#include "servconf.h"
#include "xmalloc.h"
/* Initializes the server options to their default values. */
void initialize_server_options(ServerOptions *options)
{
memset(options, 0, sizeof(*options));
options->port = -1;
options->listen_addr.s_addr = htonl(INADDR_ANY);
options->host_key_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;
#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;
}
void fill_default_server_options(ServerOptions *options)
{
if (options->port == -1)
{
struct servent *sp;
sp = getservbyname(SSH_SERVICE_NAME, "tcp");
if (sp)
options->port = ntohs(sp->s_port);
else
options->port = SSH_DEFAULT_PORT;
endservent();
}
if (options->host_key_file == NULL)
options->host_key_file = HOST_KEY_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 = 0;
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 = 1;
if (options->x11_display_offset == -1)
options->x11_display_offset = 1;
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 = 1;
if (options->rsa_authentication == -1)
options->rsa_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 = 1;
if (options->use_login == -1)
options->use_login = 0;
}
#define WHITESPACE " \t\r\n"
/* Keyword tokens. */
typedef enum
{
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
} ServerOpCodes;
/* Textual representation of the tokens. */
static struct
{
const char *name;
ServerOpCodes opcode;
} keywords[] =
{
{ "port", sPort },
{ "hostkey", sHostKeyFile },
{ "serverkeybits", sServerKeyBits },
{ "logingracetime", sLoginGraceTime },
{ "keyregenerationinterval", sKeyRegenerationTime },
{ "permitrootlogin", sPermitRootLogin },
{ "syslogfacility", sLogFacility },
{ "loglevel", sLogLevel },
{ "rhostsauthentication", sRhostsAuthentication },
{ "rhostsrsaauthentication", sRhostsRSAAuthentication },
{ "rsaauthentication", sRSAAuthentication },
#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 },
{ NULL, 0 }
};
static struct
{
const char *name;
SyslogFacility facility;
} log_facilities[] =
{
{ "DAEMON", SYSLOG_FACILITY_DAEMON },
{ "USER", SYSLOG_FACILITY_USER },
{ "AUTH", SYSLOG_FACILITY_AUTH },
{ "LOCAL0", SYSLOG_FACILITY_LOCAL0 },
{ "LOCAL1", SYSLOG_FACILITY_LOCAL1 },
{ "LOCAL2", SYSLOG_FACILITY_LOCAL2 },
{ "LOCAL3", SYSLOG_FACILITY_LOCAL3 },
{ "LOCAL4", SYSLOG_FACILITY_LOCAL4 },
{ "LOCAL5", SYSLOG_FACILITY_LOCAL5 },
{ "LOCAL6", SYSLOG_FACILITY_LOCAL6 },
{ "LOCAL7", SYSLOG_FACILITY_LOCAL7 },
{ NULL, 0 }
};
static struct
{
const char *name;
LogLevel level;
} log_levels[] =
{
{ "QUIET", SYSLOG_LEVEL_QUIET },
{ "FATAL", SYSLOG_LEVEL_FATAL },
{ "ERROR", SYSLOG_LEVEL_ERROR },
{ "INFO", SYSLOG_LEVEL_INFO },
{ "CHAT", SYSLOG_LEVEL_CHAT },
{ "DEBUG", SYSLOG_LEVEL_DEBUG },
{ 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 (strcmp(cp, keywords[i].name) == 0)
return keywords[i].opcode;
fprintf(stderr, "%s line %d: Bad configuration option: %s\n",
filename, linenum, cp);
exit(1);
}
/* 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, i, value;
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);
{
char *t = cp;
for (; *t != 0; t++)
if ('A' <= *t && *t <= 'Z')
*t = *t - 'A' + 'a'; /* tolower */
}
opcode = parse_token(cp, filename, linenum);
switch (opcode)
{
case sPort:
intptr = &options->port;
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 sServerKeyBits:
intptr = &options->server_key_bits;
goto parse_int;
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)
{
fprintf(stderr, "%s line %d: missing inet addr.\n",
filename, linenum);
exit(1);
}
options->listen_addr.s_addr = inet_addr(cp);
break;
case sHostKeyFile:
charptr = &options->host_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 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_int;
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;
#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 sLogFacility:
cp = strtok(NULL, WHITESPACE);
if (!cp)
{
fprintf(stderr, "%s line %d: missing facility name.\n",
filename, linenum);
exit(1);
}
for (i = 0; log_facilities[i].name; i++)
if (strcasecmp(log_facilities[i].name, cp) == 0)
break;
if (!log_facilities[i].name)
{
fprintf(stderr, "%s line %d: unsupported log facility %s\n",
filename, linenum, cp);
exit(1);
}
if (options->log_facility == (SyslogFacility)(-1))
options->log_facility = log_facilities[i].facility;
break;
case sLogLevel:
cp = strtok(NULL, WHITESPACE);
if (!cp)
{
fprintf(stderr, "%s line %d: missing level name.\n",
filename, linenum);
exit(1);
}
for (i = 0; log_levels[i].name; i++)
if (strcasecmp(log_levels[i].name, cp) == 0)
break;
if (!log_levels[i].name)
{
fprintf(stderr, "%s line %d: unsupported log level %s\n",
filename, linenum, cp);
exit(1);
}
if (options->log_level == (LogLevel)(-1))
options->log_level = log_levels[i].level;
break;
case sAllowUsers:
while ((cp = strtok(NULL, WHITESPACE)))
{
if (options->num_allow_users >= MAX_ALLOW_USERS)
{
fprintf(stderr, "%s line %d: too many allow users.\n",
filename, linenum);
exit(1);
}
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)
{
fprintf(stderr, "%s line %d: too many deny users.\n",
filename, linenum);
exit(1);
}
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)
{
fprintf(stderr, "%s line %d: too many allow groups.\n",
filename, linenum);
exit(1);
}
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)
{
fprintf(stderr, "%s line %d: too many deny groups.\n",
filename, linenum);
exit(1);
}
options->deny_groups[options->num_deny_groups++] = xstrdup(cp);
}
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);
}