/*
* kdc/main.c
*
* Portions Copyright (C) 2007 Apple Inc.
* Copyright 1990,2001 by the Massachusetts Institute of Technology.
*
* Export of this software from the United States of America may
* require a specific license from the United States Government.
* It is the responsibility of any person or organization contemplating
* export to obtain such a license before exporting.
*
* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
* distribute this software and its documentation for any purpose and
* without fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright notice and
* this permission notice appear in supporting documentation, and that
* the name of M.I.T. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. Furthermore if you modify this software you must label
* your software as modified software and not distribute it in such a
* fashion that it might be confused with the original M.I.T. software.
* M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*
*
* Main procedure body for the KDC server process.
*/
#include <stdio.h>
#include <syslog.h>
#include <signal.h>
#include <errno.h>
#include <netdb.h>
#include "k5-int.h"
#include "com_err.h"
#include "adm.h"
#include "adm_proto.h"
#include "kdc_util.h"
#include "extern.h"
#include "kdc5_err.h"
#include "kdb_kt.h"
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef KRB5_KRB4_COMPAT
#include <des.h>
#endif
#if defined(NEED_DAEMON_PROTO)
extern int daemon(int, int);
#endif
void usage (char *);
krb5_sigtype request_exit (int);
krb5_sigtype request_hup (int);
krb5_sigtype request_network (int);
void setup_signal_handlers (void);
krb5_error_code setup_sam (void);
void initialize_realms (krb5_context, int, char **);
void finish_realms (char *);
static int nofork = 0;
static int rkey_init_done = 0;
#ifdef POSIX_SIGNALS
static struct sigaction s_action;
#endif /* POSIX_SIGNALS */
#define KRB5_KDC_MAX_REALMS 32
/*
* Find the realm entry for a given realm.
*/
kdc_realm_t *
find_realm_data(char *rname, krb5_ui_4 rsize)
{
int i;
for (i=0; i<kdc_numrealms; i++) {
if ((rsize == strlen(kdc_realmlist[i]->realm_name)) &&
!strncmp(rname, kdc_realmlist[i]->realm_name, rsize))
return(kdc_realmlist[i]);
}
return((kdc_realm_t *) NULL);
}
krb5_error_code
setup_server_realm(krb5_principal sprinc)
{
krb5_error_code kret;
kdc_realm_t *newrealm;
kret = 0;
if (kdc_numrealms > 1) {
if (!(newrealm = find_realm_data(sprinc->realm.data,
(krb5_ui_4) sprinc->realm.length)))
kret = ENOENT;
else
kdc_active_realm = newrealm;
}
else
kdc_active_realm = kdc_realmlist[0];
return(kret);
}
static void
finish_realm(kdc_realm_t *rdp)
{
if (rdp->realm_dbname)
free(rdp->realm_dbname);
if (rdp->realm_mpname)
free(rdp->realm_mpname);
if (rdp->realm_stash)
free(rdp->realm_stash);
if (rdp->realm_ports)
free(rdp->realm_ports);
if (rdp->realm_tcp_ports)
free(rdp->realm_tcp_ports);
if (rdp->realm_keytab)
krb5_kt_close(rdp->realm_context, rdp->realm_keytab);
if (rdp->realm_context) {
if (rdp->realm_mprinc)
krb5_free_principal(rdp->realm_context, rdp->realm_mprinc);
if (rdp->realm_mkey.length && rdp->realm_mkey.contents) {
memset(rdp->realm_mkey.contents, 0, rdp->realm_mkey.length);
free(rdp->realm_mkey.contents);
}
krb5_db_fini(rdp->realm_context);
if (rdp->realm_tgsprinc)
krb5_free_principal(rdp->realm_context, rdp->realm_tgsprinc);
krb5_free_context(rdp->realm_context);
}
memset((char *) rdp, 0, sizeof(*rdp));
free(rdp);
}
/*
* Initialize a realm control structure from the alternate profile or from
* the specified defaults.
*
* After we're complete here, the essence of the realm is embodied in the
* realm data and we should be all set to begin operation for that realm.
*/
static krb5_error_code
init_realm(char *progname, kdc_realm_t *rdp, char *realm,
char *def_mpname, krb5_enctype def_enctype, char *def_udp_ports,
char *def_tcp_ports, krb5_boolean def_manual, char **db_args)
{
krb5_error_code kret;
krb5_boolean manual;
krb5_realm_params *rparams;
memset((char *) rdp, 0, sizeof(kdc_realm_t));
if (!realm) {
kret = EINVAL;
goto whoops;
}
rdp->realm_name = realm;
kret = krb5int_init_context_kdc(&rdp->realm_context);
if (kret) {
com_err(progname, kret, "while getting context for realm %s",
realm);
goto whoops;
}
kret = krb5_read_realm_params(rdp->realm_context, rdp->realm_name,
&rparams);
if (kret) {
com_err(progname, kret, "while reading realm parameters");
goto whoops;
}
/* Handle profile file name */
if (rparams && rparams->realm_profile)
rdp->realm_profile = strdup(rparams->realm_profile);
/* Handle master key name */
if (rparams && rparams->realm_mkey_name)
rdp->realm_mpname = strdup(rparams->realm_mkey_name);
else
rdp->realm_mpname = (def_mpname) ? strdup(def_mpname) :
strdup(KRB5_KDB_M_NAME);
/* Handle KDC ports */
if (rparams && rparams->realm_kdc_ports)
rdp->realm_ports = strdup(rparams->realm_kdc_ports);
else
rdp->realm_ports = strdup(def_udp_ports);
if (rparams && rparams->realm_kdc_tcp_ports)
rdp->realm_tcp_ports = strdup(rparams->realm_kdc_tcp_ports);
else
rdp->realm_tcp_ports = strdup(def_tcp_ports);
/* Handle stash file */
if (rparams && rparams->realm_stash_file) {
rdp->realm_stash = strdup(rparams->realm_stash_file);
manual = FALSE;
} else
manual = def_manual;
/* Handle master key type */
if (rparams && rparams->realm_enctype_valid)
rdp->realm_mkey.enctype = (krb5_enctype) rparams->realm_enctype;
else
rdp->realm_mkey.enctype = manual ? def_enctype : ENCTYPE_UNKNOWN;
/* Handle reject-bad-transit flag */
if (rparams && rparams->realm_reject_bad_transit_valid)
rdp->realm_reject_bad_transit = rparams->realm_reject_bad_transit;
else
rdp->realm_reject_bad_transit = 1;
/* Handle ticket maximum life */
rdp->realm_maxlife = (rparams && rparams->realm_max_life_valid) ?
rparams->realm_max_life : KRB5_KDB_MAX_LIFE;
/* Handle ticket renewable maximum life */
rdp->realm_maxrlife = (rparams && rparams->realm_max_rlife_valid) ?
rparams->realm_max_rlife : KRB5_KDB_MAX_RLIFE;
if (rparams)
krb5_free_realm_params(rdp->realm_context, rparams);
/*
* We've got our parameters, now go and setup our realm context.
*/
/* Set the default realm of this context */
if ((kret = krb5_set_default_realm(rdp->realm_context, realm))) {
com_err(progname, kret, "while setting default realm to %s",
realm);
goto whoops;
}
/* first open the database before doing anything */
#ifdef KRBCONF_KDC_MODIFIES_KDB
if ((kret = krb5_db_open(rdp->realm_context, db_args,
KRB5_KDB_OPEN_RW | KRB5_KDB_SRV_TYPE_KDC))) {
#else
if ((kret = krb5_db_open(rdp->realm_context, db_args,
KRB5_KDB_OPEN_RO | KRB5_KDB_SRV_TYPE_KDC))) {
#endif
com_err(progname, kret,
"while initializing database for realm %s", realm);
goto whoops;
}
/* Assemble and parse the master key name */
if ((kret = krb5_db_setup_mkey_name(rdp->realm_context, rdp->realm_mpname,
rdp->realm_name, (char **) NULL,
&rdp->realm_mprinc))) {
com_err(progname, kret,
"while setting up master key name %s for realm %s",
rdp->realm_mpname, realm);
goto whoops;
}
/*
* Get the master key.
*/
if ((kret = krb5_db_fetch_mkey(rdp->realm_context, rdp->realm_mprinc,
rdp->realm_mkey.enctype, manual,
FALSE, rdp->realm_stash,
0, &rdp->realm_mkey))) {
com_err(progname, kret,
"while fetching master key %s for realm %s",
rdp->realm_mpname, realm);
goto whoops;
}
/* Verify the master key */
if ((kret = krb5_db_verify_master_key(rdp->realm_context,
rdp->realm_mprinc,
&rdp->realm_mkey))) {
com_err(progname, kret,
"while verifying master key for realm %s", realm);
goto whoops;
}
if ((kret = krb5_db_set_mkey(rdp->realm_context, &rdp->realm_mkey))) {
com_err(progname, kret,
"while setting master key for realm %s", realm);
goto whoops;
}
/* Set up the keytab */
if ((kret = krb5_ktkdb_resolve(rdp->realm_context, NULL,
&rdp->realm_keytab))) {
com_err(progname, kret,
"while resolving kdb keytab for realm %s", realm);
goto whoops;
}
/* Preformat the TGS name */
if ((kret = krb5_build_principal(rdp->realm_context, &rdp->realm_tgsprinc,
strlen(realm), realm, KRB5_TGS_NAME,
realm, (char *) NULL))) {
com_err(progname, kret,
"while building TGS name for realm %s", realm);
goto whoops;
}
if (!rkey_init_done) {
krb5_data seed;
#ifdef KRB5_KRB4_COMPAT
krb5_keyblock temp_key;
#endif
/*
* If all that worked, then initialize the random key
* generators.
*/
seed.length = rdp->realm_mkey.length;
seed.data = rdp->realm_mkey.contents;
if ((kret = krb5_c_random_add_entropy(rdp->realm_context,
KRB5_C_RANDSOURCE_TRUSTEDPARTY, &seed)))
goto whoops;
#ifdef KRB5_KRB4_COMPAT
if ((kret = krb5_c_make_random_key(rdp->realm_context,
ENCTYPE_DES_CBC_CRC, &temp_key))) {
com_err(progname, kret,
"while initializing V4 random key generator");
goto whoops;
}
(void) des_init_random_number_generator(temp_key.contents);
krb5_free_keyblock_contents(rdp->realm_context, &temp_key);
#endif
rkey_init_done = 1;
}
whoops:
/*
* If we choked, then clean up any dirt we may have dropped on the floor.
*/
if (kret) {
finish_realm(rdp);
}
return(kret);
}
krb5_sigtype
request_exit(int signo)
{
signal_requests_exit = 1;
#ifdef POSIX_SIGTYPE
return;
#else
return(0);
#endif
}
krb5_sigtype
request_hup(int signo)
{
signal_requests_hup = 1;
#ifdef POSIX_SIGTYPE
return;
#else
return(0);
#endif
}
krb5_sigtype
request_network(int signo)
{
signal_requests_network = 1;
#ifdef POSIX_SIGTYPE
return;
#else
return(0);
#endif
}
void
setup_signal_handlers(void)
{
#ifdef POSIX_SIGNALS
(void) sigemptyset(&s_action.sa_mask);
s_action.sa_flags = 0;
s_action.sa_handler = request_exit;
(void) sigaction(SIGINT, &s_action, (struct sigaction *) NULL);
(void) sigaction(SIGTERM, &s_action, (struct sigaction *) NULL);
s_action.sa_handler = request_hup;
(void) sigaction(SIGHUP, &s_action, (struct sigaction *) NULL);
s_action.sa_handler = request_network;
(void) sigaction(SIGUSR1, &s_action, (struct sigaction *) NULL);
s_action.sa_handler = SIG_IGN;
(void) sigaction(SIGPIPE, &s_action, (struct sigaction *) NULL);
#else /* POSIX_SIGNALS */
signal(SIGINT, request_exit);
signal(SIGTERM, request_exit);
signal(SIGHUP, request_hup);
signal(SIGUSR1, request_network);
signal(SIGPIPE, SIG_IGN);
#endif /* POSIX_SIGNALS */
return;
}
krb5_error_code
setup_sam(void)
{
return krb5_c_make_random_key(kdc_context, ENCTYPE_DES_CBC_MD5, &psr_key);
}
void
usage(char *name)
{
fprintf(stderr, "usage: %s [-x db_args]* [-d dbpathname] [-r dbrealmname] [-R replaycachename ]\n\t[-m] [-k masterenctype] [-a] [-M masterkeyname] [-p port] [-4 v4mode] [-X] [-n]\n"
"\nwhere,\n\t[-x db_args]* - any number of database specific arguments.\n"
"\t\t\tLook at each database documentation for supported arguments\n",
name);
return;
}
void
initialize_realms(krb5_context kcontext, int argc, char **argv)
{
int c;
char *db_name = (char *) NULL;
char *mkey_name = (char *) NULL;
char *rcname = KDCRCACHE;
char *lrealm;
krb5_error_code retval;
krb5_enctype menctype = ENCTYPE_UNKNOWN;
kdc_realm_t *rdatap;
krb5_boolean manual = FALSE;
char *default_udp_ports = 0;
char *default_tcp_ports = 0;
krb5_pointer aprof;
const char *hierarchy[3];
char **db_args = NULL;
int db_args_size = 0;
#ifdef KRB5_KRB4_COMPAT
char *v4mode = 0;
#endif
extern char *optarg;
#ifndef APPLE_KDC_MODS
#define APPLE_KDC_MODS
#endif
#ifdef APPLE_KDC_MODS
const char *arg_string = "r:ad:mM:k:R:e:p:s:n4:X3";
#else
const char *arg_string = "r:d:mM:k:R:e:p:s:n4:X3";
#endif
if (!krb5_aprof_init(DEFAULT_KDC_PROFILE, KDC_PROFILE_ENV, &aprof)) {
hierarchy[0] = "kdcdefaults";
hierarchy[1] = "kdc_ports";
hierarchy[2] = (char *) NULL;
if (krb5_aprof_get_string(aprof, hierarchy, TRUE, &default_udp_ports))
default_udp_ports = 0;
hierarchy[1] = "kdc_tcp_ports";
if (krb5_aprof_get_string(aprof, hierarchy, TRUE, &default_tcp_ports))
default_tcp_ports = 0;
#ifdef KRB5_KRB4_COMPAT
hierarchy[1] = "v4_mode";
if (krb5_aprof_get_string(aprof, hierarchy, TRUE, &v4mode))
v4mode = 0;
#endif
/* aprof_init can return 0 with aprof == NULL */
if (aprof)
krb5_aprof_finish(aprof);
}
if (default_udp_ports == 0)
default_udp_ports = strdup(DEFAULT_KDC_UDP_PORTLIST);
if (default_tcp_ports == 0)
default_tcp_ports = strdup(DEFAULT_KDC_TCP_PORTLIST);
/*
* Loop through the option list. Each time we encounter a realm name,
* use the previously scanned options to fill in for defaults.
*/
while ((c = getopt(argc, argv, arg_string)) != -1) {
switch(c) {
case 'x':
db_args_size++;
{
char **temp = realloc( db_args, sizeof(char*) * (db_args_size+1)); /* one for NULL */
if( temp == NULL )
{
fprintf(stderr,"%s: KDC cannot initialize. Not enough memory\n",
argv[0]);
exit(1);
}
db_args = temp;
}
db_args[db_args_size-1] = optarg;
db_args[db_args_size] = NULL;
break;
case 'r': /* realm name for db */
if (!find_realm_data(optarg, (krb5_ui_4) strlen(optarg))) {
if ((rdatap = (kdc_realm_t *) malloc(sizeof(kdc_realm_t)))) {
if ((retval = init_realm(argv[0], rdatap, optarg,
mkey_name, menctype,
default_udp_ports,
default_tcp_ports, manual, db_args))) {
fprintf(stderr,"%s: cannot initialize realm %s - see log file for details\n",
argv[0], optarg);
exit(1);
}
kdc_realmlist[kdc_numrealms] = rdatap;
kdc_numrealms++;
free(db_args), db_args=NULL, db_args_size = 0;
}
else
{
fprintf(stderr,"%s: cannot initialize realm %s. Not enough memory\n",
argv[0], optarg);
exit(1);
}
}
break;
#ifdef APPLE_KDC_MODS
case 'a': /* Apple password server mod */
kdc_notify_pws_apple = 1;
break;
#endif
case 'd': /* pathname for db */
/* now db_name is not a seperate argument. It has to be passed as part of the db_args */
if( db_name == NULL )
{
db_name = malloc(sizeof("dbname=") + strlen(optarg));
if( db_name == NULL )
{
fprintf(stderr,"%s: KDC cannot initialize. Not enough memory\n",
argv[0] );
exit(1);
}
sprintf( db_name, "dbname=%s", optarg);
}
db_args_size++;
{
char **temp = realloc( db_args, sizeof(char*) * (db_args_size+1)); /* one for NULL */
if( temp == NULL )
{
fprintf(stderr,"%s: KDC cannot initialize. Not enough memory\n",
argv[0]);
exit(1);
}
db_args = temp;
}
db_args[db_args_size-1] = db_name;
db_args[db_args_size] = NULL;
break;
case 'm': /* manual type-in of master key */
manual = TRUE;
if (menctype == ENCTYPE_UNKNOWN)
menctype = ENCTYPE_DES_CBC_CRC;
break;
case 'M': /* master key name in DB */
mkey_name = optarg;
break;
case 'n':
nofork++; /* don't detach from terminal */
break;
case 'k': /* enctype for master key */
if (krb5_string_to_enctype(optarg, &menctype))
com_err(argv[0], 0, "invalid enctype %s", optarg);
break;
case 'R':
rcname = optarg;
break;
case 'p':
if (default_udp_ports)
free(default_udp_ports);
default_udp_ports = strdup(optarg);
#if 0 /* not yet */
if (default_tcp_ports)
free(default_tcp_ports);
default_tcp_ports = strdup(optarg);
#endif
break;
case '4':
#ifdef KRB5_KRB4_COMPAT
if (v4mode)
free(v4mode);
v4mode = strdup(optarg);
#endif
break;
case 'X':
#ifdef KRB5_KRB4_COMPAT
enable_v4_crossrealm(argv[0]);
#endif
break;
case '?':
default:
usage(argv[0]);
exit(1);
}
}
#ifdef KRB5_KRB4_COMPAT
/*
* Setup the v4 mode
*/
process_v4_mode(argv[0], v4mode);
free(v4mode);
#endif
/*
* Check to see if we processed any realms.
*/
if (kdc_numrealms == 0) {
/* no realm specified, use default realm */
if ((retval = krb5_get_default_realm(kcontext, &lrealm))) {
com_err(argv[0], retval,
"while attempting to retrieve default realm");
fprintf (stderr, "%s: %s, attempting to retrieve default realm\n",
argv[0], krb5_get_error_message(kcontext, retval));
exit(1);
}
if ((rdatap = (kdc_realm_t *) malloc(sizeof(kdc_realm_t)))) {
if ((retval = init_realm(argv[0], rdatap, lrealm,
mkey_name, menctype, default_udp_ports,
default_tcp_ports, manual, db_args))) {
fprintf(stderr,"%s: cannot initialize realm %s - see log file for details\n",
argv[0], lrealm);
exit(1);
}
kdc_realmlist[0] = rdatap;
kdc_numrealms++;
}
}
#ifdef USE_RCACHE
/*
* Now handle the replay cache.
*/
if ((retval = kdc_initialize_rcache(kcontext, rcname))) {
com_err(argv[0], retval, "while initializing KDC replay cache '%s'",
rcname);
exit(1);
}
#endif
/* Ensure that this is set for our first request. */
kdc_active_realm = kdc_realmlist[0];
if (default_udp_ports)
free(default_udp_ports);
if (default_tcp_ports)
free(default_tcp_ports);
if (db_args)
free(db_args);
if (db_name)
free(db_name);
return;
}
void
finish_realms(char *prog)
{
int i;
for (i = 0; i < kdc_numrealms; i++) {
finish_realm(kdc_realmlist[i]);
kdc_realmlist[i] = 0;
}
}
/*
outline:
process args & setup
initialize database access (fetch master key, open DB)
initialize network
loop:
listen for packet
determine packet type, dispatch to handling routine
(AS or TGS (or V4?))
reflect response
exit on signal
clean up secrets, close db
shut down network
exit
*/
int main(int argc, char **argv)
{
krb5_error_code retval;
krb5_context kcontext;
int errout = 0;
if (strrchr(argv[0], '/'))
argv[0] = strrchr(argv[0], '/')+1;
if (!(kdc_realmlist = (kdc_realm_t **) malloc(sizeof(kdc_realm_t *) *
KRB5_KDC_MAX_REALMS))) {
fprintf(stderr, "%s: cannot get memory for realm list\n", argv[0]);
exit(1);
}
memset((char *) kdc_realmlist, 0,
(size_t) (sizeof(kdc_realm_t *) * KRB5_KDC_MAX_REALMS));
/*
* A note about Kerberos contexts: This context, "kcontext", is used
* for the KDC operations, i.e. setup, network connection and error
* reporting. The per-realm operations use the "realm_context"
* associated with each realm.
*/
retval = krb5int_init_context_kdc(&kcontext);
if (retval) {
com_err(argv[0], retval, "while initializing krb5");
exit(1);
}
krb5_klog_init(kcontext, "kdc", argv[0], 1);
/* N.B.: After this point, com_err sends output to the KDC log
file, and not to stderr. */
initialize_kdc5_error_table();
/*
* Scan through the argument list
*/
initialize_realms(kcontext, argc, argv);
setup_signal_handlers();
load_preauth_plugins(kcontext);
load_authdata_plugins(kcontext);
retval = setup_sam();
if (retval) {
com_err(argv[0], retval, "while initializing SAM");
finish_realms(argv[0]);
return 1;
}
if ((retval = setup_network(argv[0]))) {
com_err(argv[0], retval, "while initializing network");
finish_realms(argv[0]);
return 1;
}
if (!nofork && daemon(0, 0)) {
com_err(argv[0], errno, "while detaching from tty");
finish_realms(argv[0]);
return 1;
}
krb5_klog_syslog(LOG_INFO, "commencing operation");
if ((retval = listen_and_process(argv[0]))) {
com_err(argv[0], retval, "while processing network requests");
errout++;
}
if ((retval = closedown_network(argv[0]))) {
com_err(argv[0], retval, "while shutting down network");
errout++;
}
krb5_klog_syslog(LOG_INFO, "shutting down");
unload_preauth_plugins(kcontext);
unload_authdata_plugins(kcontext);
krb5_klog_close(kdc_context);
finish_realms(argv[0]);
if (kdc_realmlist)
free(kdc_realmlist);
#ifdef USE_RCACHE
(void) krb5_rc_close(kcontext, kdc_rcache);
#endif
#ifndef NOCACHE
kdc_free_lookaside(kcontext);
#endif
krb5_free_context(kcontext);
return errout;
}