servconf.c - security/openssh-library - Rivoreo Source Code Repositories

 /*

 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 1.2 1999/11/11 06:57:39 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->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->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

 } 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 },
   { "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 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);
 }
	/*

	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 1.2 1999/11/11 06:57:39 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->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->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

	} 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 },
	{ "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 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);
	}