source: branches/samba-3.5.x/source4/kdc/kdc.c@ 1010

/* 
   Unix SMB/CIFS implementation.

   KDC Server startup

   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005-2008
   Copyright (C) Andrew Tridgell        2005
   Copyright (C) Stefan Metzmacher      2005

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "smbd/service_task.h"
#include "smbd/service.h"
#include "smbd/service_stream.h"
#include "smbd/process_model.h"
#include "lib/events/events.h"
#include "lib/socket/socket.h"
#include "system/network.h"
#include "../lib/util/dlinklist.h"
#include "lib/messaging/irpc.h"
#include "lib/stream/packet.h"
#include "librpc/gen_ndr/samr.h"
#include "librpc/gen_ndr/ndr_irpc.h"
#include "librpc/gen_ndr/ndr_krb5pac.h"
#include "lib/socket/netif.h"
#include "param/param.h"
#include "kdc/kdc.h"
#include "librpc/gen_ndr/ndr_misc.h"


/* Disgusting hack to get a mem_ctx and lp_ctx into the hdb plugin, when 
 * used as a keytab */
TALLOC_CTX *hdb_samba4_mem_ctx;
struct tevent_context *hdb_samba4_ev_ctx;
struct loadparm_context *hdb_samba4_lp_ctx;

/* hold all the info needed to send a reply */
struct kdc_reply {
        struct kdc_reply *next, *prev;
        struct socket_address *dest;
        DATA_BLOB packet;
};

typedef bool (*kdc_process_fn_t)(struct kdc_server *kdc,
                                 TALLOC_CTX *mem_ctx, 
                                 DATA_BLOB *input, 
                                 DATA_BLOB *reply,
                                 struct socket_address *peer_addr, 
                                 struct socket_address *my_addr, 
                                 int datagram);

/* hold information about one kdc socket */
struct kdc_socket {
        struct socket_context *sock;
        struct kdc_server *kdc;
        struct tevent_fd *fde;

        /* a queue of outgoing replies that have been deferred */
        struct kdc_reply *send_queue;

        kdc_process_fn_t process;
};
/*
  state of an open tcp connection
*/
struct kdc_tcp_connection {
        /* stream connection we belong to */
        struct stream_connection *conn;

        /* the kdc_server the connection belongs to */
        struct kdc_server *kdc;

        struct packet_context *packet;

        kdc_process_fn_t process;
};

/*
  handle fd send events on a KDC socket
*/
static void kdc_send_handler(struct kdc_socket *kdc_socket)
{
        while (kdc_socket->send_queue) {
                struct kdc_reply *rep = kdc_socket->send_queue;
                NTSTATUS status;
                size_t sendlen;

                status = socket_sendto(kdc_socket->sock, &rep->packet, &sendlen,
                                       rep->dest);
                if (NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
                        break;
                }
                if (NT_STATUS_EQUAL(status, NT_STATUS_INVALID_BUFFER_SIZE)) {
                        /* Replace with a krb err, response to big */
                }
                
                DLIST_REMOVE(kdc_socket->send_queue, rep);
                talloc_free(rep);
        }

        if (kdc_socket->send_queue == NULL) {
                EVENT_FD_NOT_WRITEABLE(kdc_socket->fde);
        }
}


/*
  handle fd recv events on a KDC socket
*/
static void kdc_recv_handler(struct kdc_socket *kdc_socket)
{
        NTSTATUS status;
        TALLOC_CTX *tmp_ctx = talloc_new(kdc_socket);
        DATA_BLOB blob;
        struct kdc_reply *rep;
        DATA_BLOB reply;
        size_t nread, dsize;
        struct socket_address *src;
        struct socket_address *my_addr;
        int ret;

        status = socket_pending(kdc_socket->sock, &dsize);
        if (!NT_STATUS_IS_OK(status)) {
                talloc_free(tmp_ctx);
                return;
        }

        blob = data_blob_talloc(tmp_ctx, NULL, dsize);
        if (blob.data == NULL) {
                /* hope this is a temporary low memory condition */
                talloc_free(tmp_ctx);
                return;
        }

        status = socket_recvfrom(kdc_socket->sock, blob.data, blob.length, &nread,
                                 tmp_ctx, &src);
        if (!NT_STATUS_IS_OK(status)) {
                talloc_free(tmp_ctx);
                return;
        }
        blob.length = nread;
        
        DEBUG(10,("Received krb5 UDP packet of length %lu from %s:%u\n", 
                 (long)blob.length, src->addr, (uint16_t)src->port));
        
        my_addr = socket_get_my_addr(kdc_socket->sock, tmp_ctx);
        if (!my_addr) {
                talloc_free(tmp_ctx);
                return;
        }


        /* Call krb5 */
        ret = kdc_socket->process(kdc_socket->kdc, 
                                  tmp_ctx, 
                                  &blob,  
                                  &reply,
                                  src, my_addr,
                                  1 /* Datagram */);
        if (!ret) {
                talloc_free(tmp_ctx);
                return;
        }

        /* queue a pending reply */
        rep = talloc(kdc_socket, struct kdc_reply);
        if (rep == NULL) {
                talloc_free(tmp_ctx);
                return;
        }
        rep->dest         = talloc_steal(rep, src);
        rep->packet       = reply;
        talloc_steal(rep, reply.data);

        if (rep->packet.data == NULL) {
                talloc_free(rep);
                talloc_free(tmp_ctx);
                return;
        }

        DLIST_ADD_END(kdc_socket->send_queue, rep, struct kdc_reply *);
        EVENT_FD_WRITEABLE(kdc_socket->fde);
        talloc_free(tmp_ctx);
}

/*
  handle fd events on a KDC socket
*/
static void kdc_socket_handler(struct tevent_context *ev, struct tevent_fd *fde,
                               uint16_t flags, void *private_data)
{
        struct kdc_socket *kdc_socket = talloc_get_type(private_data, struct kdc_socket);
        if (flags & EVENT_FD_WRITE) {
                kdc_send_handler(kdc_socket);
        } 
        if (flags & EVENT_FD_READ) {
                kdc_recv_handler(kdc_socket);
        }
}

static void kdc_tcp_terminate_connection(struct kdc_tcp_connection *kdcconn, const char *reason)
{
        stream_terminate_connection(kdcconn->conn, reason);
}

/*
  receive a full packet on a KDC connection
*/
static NTSTATUS kdc_tcp_recv(void *private_data, DATA_BLOB blob)
{
        struct kdc_tcp_connection *kdcconn = talloc_get_type(private_data,
                                                             struct kdc_tcp_connection);
        NTSTATUS status = NT_STATUS_UNSUCCESSFUL;
        TALLOC_CTX *tmp_ctx = talloc_new(kdcconn);
        int ret;
        DATA_BLOB input, reply;
        struct socket_address *src_addr;
        struct socket_address *my_addr;

        talloc_steal(tmp_ctx, blob.data);

        src_addr = socket_get_peer_addr(kdcconn->conn->socket, tmp_ctx);
        if (!src_addr) {
                talloc_free(tmp_ctx);
                return NT_STATUS_NO_MEMORY;
        }

        my_addr = socket_get_my_addr(kdcconn->conn->socket, tmp_ctx);
        if (!my_addr) {
                talloc_free(tmp_ctx);
                return NT_STATUS_NO_MEMORY;
        }

        /* Call krb5 */
        input = data_blob_const(blob.data + 4, blob.length - 4); 

        ret = kdcconn->process(kdcconn->kdc, 
                               tmp_ctx,
                               &input,
                               &reply,
                               src_addr,
                               my_addr,
                               0 /* Not datagram */);
        if (!ret) {
                talloc_free(tmp_ctx);
                return NT_STATUS_INTERNAL_ERROR;
        }

        /* and now encode the reply */
        blob = data_blob_talloc(kdcconn, NULL, reply.length + 4);
        if (!blob.data) {
                talloc_free(tmp_ctx);
                return NT_STATUS_NO_MEMORY;
        }

        RSIVAL(blob.data, 0, reply.length);
        memcpy(blob.data + 4, reply.data, reply.length);        

        status = packet_send(kdcconn->packet, blob);
        if (!NT_STATUS_IS_OK(status)) {
                talloc_free(tmp_ctx);
                return status;
        }

        /* the call isn't needed any more */
        talloc_free(tmp_ctx);
        return NT_STATUS_OK;
}

/*
  receive some data on a KDC connection
*/
static void kdc_tcp_recv_handler(struct stream_connection *conn, uint16_t flags)
{
        struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private_data,
                                                             struct kdc_tcp_connection);
        packet_recv(kdcconn->packet);
}

/*
  called on a tcp recv error
*/
static void kdc_tcp_recv_error(void *private_data, NTSTATUS status)
{
        struct kdc_tcp_connection *kdcconn = talloc_get_type(private_data,
                                             struct kdc_tcp_connection);
        kdc_tcp_terminate_connection(kdcconn, nt_errstr(status));
}

/*
  called when we can write to a connection
*/
static void kdc_tcp_send(struct stream_connection *conn, uint16_t flags)
{
        struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private_data,
                                                             struct kdc_tcp_connection);
        packet_queue_run(kdcconn->packet);
}

/**
   Wrapper for krb5_kdc_process_krb5_request, converting to/from Samba
   calling conventions
*/

static bool kdc_process(struct kdc_server *kdc,
                        TALLOC_CTX *mem_ctx, 
                        DATA_BLOB *input, 
                        DATA_BLOB *reply,
                        struct socket_address *peer_addr, 
                        struct socket_address *my_addr,
                        int datagram_reply)
{
        int ret;        
        krb5_data k5_reply;
        krb5_data_zero(&k5_reply);

        krb5_kdc_update_time(NULL);

        DEBUG(10,("Received KDC packet of length %lu from %s:%d\n", 
                  (long)input->length - 4, peer_addr->addr, peer_addr->port));

        ret = krb5_kdc_process_krb5_request(kdc->smb_krb5_context->krb5_context, 
                                            kdc->config,
                                            input->data, input->length,
                                            &k5_reply,
                                            peer_addr->addr,
                                            peer_addr->sockaddr,
                                            datagram_reply);
        if (ret == -1) {
                *reply = data_blob(NULL, 0);
                return false;
        }
        if (k5_reply.length) {
                *reply = data_blob_talloc(mem_ctx, k5_reply.data, k5_reply.length);
                krb5_data_free(&k5_reply);
        } else {
                *reply = data_blob(NULL, 0);    
        }
        return true;
}

/*
  called when we get a new connection
*/
static void kdc_tcp_generic_accept(struct stream_connection *conn, kdc_process_fn_t process_fn)
{
        struct kdc_server *kdc = talloc_get_type(conn->private_data, struct kdc_server);
        struct kdc_tcp_connection *kdcconn;

        kdcconn = talloc_zero(conn, struct kdc_tcp_connection);
        if (!kdcconn) {
                stream_terminate_connection(conn, "kdc_tcp_accept: out of memory");
                return;
        }
        kdcconn->conn    = conn;
        kdcconn->kdc     = kdc;
        kdcconn->process = process_fn;
        conn->private_data    = kdcconn;

        kdcconn->packet = packet_init(kdcconn);
        if (kdcconn->packet == NULL) {
                kdc_tcp_terminate_connection(kdcconn, "kdc_tcp_accept: out of memory");
                return;
        }
        packet_set_private(kdcconn->packet, kdcconn);
        packet_set_socket(kdcconn->packet, conn->socket);
        packet_set_callback(kdcconn->packet, kdc_tcp_recv);
        packet_set_full_request(kdcconn->packet, packet_full_request_u32);
        packet_set_error_handler(kdcconn->packet, kdc_tcp_recv_error);
        packet_set_event_context(kdcconn->packet, conn->event.ctx);
        packet_set_fde(kdcconn->packet, conn->event.fde);
        packet_set_serialise(kdcconn->packet);
}

static void kdc_tcp_accept(struct stream_connection *conn)
{
        kdc_tcp_generic_accept(conn, kdc_process);
}

static const struct stream_server_ops kdc_tcp_stream_ops = {
        .name                   = "kdc_tcp",
        .accept_connection      = kdc_tcp_accept,
        .recv_handler           = kdc_tcp_recv_handler,
        .send_handler           = kdc_tcp_send
};

static void kpasswdd_tcp_accept(struct stream_connection *conn)
{
        kdc_tcp_generic_accept(conn, kpasswdd_process);
}

static const struct stream_server_ops kpasswdd_tcp_stream_ops = {
        .name                   = "kpasswdd_tcp",
        .accept_connection      = kpasswdd_tcp_accept,
        .recv_handler           = kdc_tcp_recv_handler,
        .send_handler           = kdc_tcp_send
};

/*
  start listening on the given address
*/
static NTSTATUS kdc_add_socket(struct kdc_server *kdc, const char *address,
                               uint16_t kdc_port, uint16_t kpasswd_port)
{
        const struct model_ops *model_ops;
        struct kdc_socket *kdc_socket;
        struct kdc_socket *kpasswd_socket;
        struct socket_address *kdc_address, *kpasswd_address;
        NTSTATUS status;

        kdc_socket = talloc(kdc, struct kdc_socket);
        NT_STATUS_HAVE_NO_MEMORY(kdc_socket);

        kpasswd_socket = talloc(kdc, struct kdc_socket);
        NT_STATUS_HAVE_NO_MEMORY(kpasswd_socket);

        status = socket_create("ip", SOCKET_TYPE_DGRAM, &kdc_socket->sock, 0);
        if (!NT_STATUS_IS_OK(status)) {
                talloc_free(kdc_socket);
                return status;
        }

        status = socket_create("ip", SOCKET_TYPE_DGRAM, &kpasswd_socket->sock, 0);
        if (!NT_STATUS_IS_OK(status)) {
                talloc_free(kpasswd_socket);
                return status;
        }

        kdc_socket->kdc = kdc;
        kdc_socket->send_queue = NULL;
        kdc_socket->process = kdc_process;

        talloc_steal(kdc_socket, kdc_socket->sock);

        kdc_socket->fde = event_add_fd(kdc->task->event_ctx, kdc, 
                                       socket_get_fd(kdc_socket->sock), EVENT_FD_READ,
                                       kdc_socket_handler, kdc_socket);

        kdc_address = socket_address_from_strings(kdc_socket, kdc_socket->sock->backend_name, 
                                                  address, kdc_port);
        NT_STATUS_HAVE_NO_MEMORY(kdc_address);

        status = socket_listen(kdc_socket->sock, kdc_address, 0, 0);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(0,("Failed to bind to %s:%d UDP for kdc - %s\n", 
                         address, kdc_port, nt_errstr(status)));
                talloc_free(kdc_socket);
                return status;
        }

        kpasswd_socket->kdc = kdc;
        kpasswd_socket->send_queue = NULL;
        kpasswd_socket->process = kpasswdd_process;

        talloc_steal(kpasswd_socket, kpasswd_socket->sock);

        kpasswd_socket->fde = event_add_fd(kdc->task->event_ctx, kdc, 
                                           socket_get_fd(kpasswd_socket->sock), EVENT_FD_READ,
                                           kdc_socket_handler, kpasswd_socket);
        
        kpasswd_address = socket_address_from_strings(kpasswd_socket, kpasswd_socket->sock->backend_name, 
                                                      address, kpasswd_port);
        NT_STATUS_HAVE_NO_MEMORY(kpasswd_address);

        status = socket_listen(kpasswd_socket->sock, kpasswd_address, 0, 0);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(0,("Failed to bind to %s:%d UDP for kpasswd - %s\n", 
                         address, kpasswd_port, nt_errstr(status)));
                talloc_free(kpasswd_socket);
                return status;
        }

        /* within the kdc task we want to be a single process, so
           ask for the single process model ops and pass these to the
           stream_setup_socket() call. */
        model_ops = process_model_startup(kdc->task->event_ctx, "single");
        if (!model_ops) {
                DEBUG(0,("Can't find 'single' process model_ops\n"));
                talloc_free(kdc_socket);
                return NT_STATUS_INTERNAL_ERROR;
        }

        status = stream_setup_socket(kdc->task->event_ctx, 
                                     kdc->task->lp_ctx,
                                     model_ops, 
                                     &kdc_tcp_stream_ops, 
                                     "ip", address, &kdc_port, 
                                     lp_socket_options(kdc->task->lp_ctx), 
                                     kdc);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
                         address, kdc_port, nt_errstr(status)));
                talloc_free(kdc_socket);
                return status;
        }

        status = stream_setup_socket(kdc->task->event_ctx, 
                                     kdc->task->lp_ctx,
                                     model_ops, 
                                     &kpasswdd_tcp_stream_ops, 
                                     "ip", address, &kpasswd_port, 
                                     lp_socket_options(kdc->task->lp_ctx), 
                                     kdc);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
                         address, kpasswd_port, nt_errstr(status)));
                talloc_free(kdc_socket);
                return status;
        }

        return NT_STATUS_OK;
}


/*
  setup our listening sockets on the configured network interfaces
*/
static NTSTATUS kdc_startup_interfaces(struct kdc_server *kdc, struct loadparm_context *lp_ctx,
                                       struct interface *ifaces)
{
        int num_interfaces;
        TALLOC_CTX *tmp_ctx = talloc_new(kdc);
        NTSTATUS status;
        int i;

        num_interfaces = iface_count(ifaces);
        
        for (i=0; i<num_interfaces; i++) {
                const char *address = talloc_strdup(tmp_ctx, iface_n_ip(ifaces, i));
                status = kdc_add_socket(kdc, address, lp_krb5_port(lp_ctx), 
                                        lp_kpasswd_port(lp_ctx));
                NT_STATUS_NOT_OK_RETURN(status);
        }

        talloc_free(tmp_ctx);

        return NT_STATUS_OK;
}


static NTSTATUS kdc_check_generic_kerberos(struct irpc_message *msg, 
                                 struct kdc_check_generic_kerberos *r)
{
        struct PAC_Validate pac_validate;
        DATA_BLOB srv_sig;
        struct PAC_SIGNATURE_DATA kdc_sig;
        struct kdc_server *kdc = talloc_get_type(msg->private_data, struct kdc_server);
        enum ndr_err_code ndr_err;
        krb5_enctype etype;
        int ret;
        hdb_entry_ex ent;
        krb5_principal principal;
        krb5_keyblock keyblock;
        Key *key;

        /* There is no reply to this request */
        r->out.generic_reply = data_blob(NULL, 0);

        ndr_err = ndr_pull_struct_blob(&r->in.generic_request, msg, 
                                       lp_iconv_convenience(kdc->task->lp_ctx), 
                                       &pac_validate,
                                       (ndr_pull_flags_fn_t)ndr_pull_PAC_Validate);
        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                return NT_STATUS_INVALID_PARAMETER;
        }
        
        if (pac_validate.MessageType != 3) {
                /* We don't implement any other message types - such as certificate validation - yet */
                return NT_STATUS_INVALID_PARAMETER;
        }

        if (pac_validate.ChecksumAndSignature.length != (pac_validate.ChecksumLength + pac_validate.SignatureLength)
            || pac_validate.ChecksumAndSignature.length < pac_validate.ChecksumLength
            || pac_validate.ChecksumAndSignature.length < pac_validate.SignatureLength ) {
                return NT_STATUS_INVALID_PARAMETER;
        }
        
        srv_sig = data_blob_const(pac_validate.ChecksumAndSignature.data, 
                                  pac_validate.ChecksumLength);
        
        if (pac_validate.SignatureType == CKSUMTYPE_HMAC_MD5) {
                etype = ETYPE_ARCFOUR_HMAC_MD5;
        } else {
                ret = krb5_cksumtype_to_enctype(kdc->smb_krb5_context->krb5_context, pac_validate.SignatureType,
                                                &etype);
                if (ret != 0) {
                        return NT_STATUS_LOGON_FAILURE;
                }
        }

        ret = krb5_make_principal(kdc->smb_krb5_context->krb5_context, &principal, 
                                  lp_realm(kdc->task->lp_ctx), 
                                  "krbtgt", lp_realm(kdc->task->lp_ctx), 
                                  NULL);

        if (ret != 0) {
                return NT_STATUS_NO_MEMORY;
        }

        ret = kdc->config->db[0]->hdb_fetch(kdc->smb_krb5_context->krb5_context, 
                                            kdc->config->db[0],
                                            principal,
                                            HDB_F_GET_KRBTGT | HDB_F_DECRYPT,
                                            &ent);

        if (ret != 0) {
                hdb_free_entry(kdc->smb_krb5_context->krb5_context, &ent);
                krb5_free_principal(kdc->smb_krb5_context->krb5_context, principal);
        
                return NT_STATUS_LOGON_FAILURE;
        }
        
        ret = hdb_enctype2key(kdc->smb_krb5_context->krb5_context, &ent.entry, etype, &key);

        if (ret != 0) {
                hdb_free_entry(kdc->smb_krb5_context->krb5_context, &ent);
                krb5_free_principal(kdc->smb_krb5_context->krb5_context, principal);
                return NT_STATUS_LOGON_FAILURE;
        }

        keyblock = key->key;
        
        kdc_sig.type = pac_validate.SignatureType;
        kdc_sig.signature = data_blob_const(&pac_validate.ChecksumAndSignature.data[pac_validate.ChecksumLength],
                                            pac_validate.SignatureLength);
        ret = check_pac_checksum(msg, srv_sig, &kdc_sig, 
                           kdc->smb_krb5_context->krb5_context, &keyblock);

        hdb_free_entry(kdc->smb_krb5_context->krb5_context, &ent);
        krb5_free_principal(kdc->smb_krb5_context->krb5_context, principal);

        if (ret != 0) {
                return NT_STATUS_LOGON_FAILURE;
        }
        
        return NT_STATUS_OK;
}


/*
  startup the kdc task
*/
static void kdc_task_init(struct task_server *task)
{
        struct kdc_server *kdc;
        NTSTATUS status;
        krb5_error_code ret;
        struct interface *ifaces;

        switch (lp_server_role(task->lp_ctx)) {
        case ROLE_STANDALONE:
                task_server_terminate(task, "kdc: no KDC required in standalone configuration", false);
                return;
        case ROLE_DOMAIN_MEMBER:
                task_server_terminate(task, "kdc: no KDC required in member server configuration", false);
                return;
        case ROLE_DOMAIN_CONTROLLER:
                /* Yes, we want a KDC */
                break;
        }

        load_interfaces(task, lp_interfaces(task->lp_ctx), &ifaces);

        if (iface_count(ifaces) == 0) {
                task_server_terminate(task, "kdc: no network interfaces configured", false);
                return;
        }

        task_server_set_title(task, "task[kdc]");

        kdc = talloc(task, struct kdc_server);
        if (kdc == NULL) {
                task_server_terminate(task, "kdc: out of memory", true);
                return;
        }

        kdc->task = task;

        initialize_krb5_error_table();

        ret = smb_krb5_init_context(kdc, task->event_ctx, task->lp_ctx, &kdc->smb_krb5_context);
        if (ret) {
                DEBUG(1,("kdc_task_init: krb5_init_context failed (%s)\n", 
                         error_message(ret)));
                task_server_terminate(task, "kdc: krb5_init_context failed", true);
                return; 
        }

        krb5_add_et_list(kdc->smb_krb5_context->krb5_context, initialize_hdb_error_table_r);

        ret = krb5_kdc_get_config(kdc->smb_krb5_context->krb5_context, 
                                  &kdc->config);
        if(ret) {
                task_server_terminate(task, "kdc: failed to get KDC configuration", true);
                return;
        }
 
        kdc->config->logf = kdc->smb_krb5_context->logf;
        kdc->config->db = talloc(kdc, struct HDB *);
        if (!kdc->config->db) {
                task_server_terminate(task, "kdc: out of memory", true);
                return;
        }
        kdc->config->num_db = 1;
                
        status = hdb_samba4_create_kdc(kdc, task->event_ctx, task->lp_ctx, 
                                       kdc->smb_krb5_context->krb5_context, 
                                       &kdc->config->db[0]);
        if (!NT_STATUS_IS_OK(status)) {
                task_server_terminate(task, "kdc: hdb_samba4_create_kdc (setup KDC database) failed", true);
                return; 
        }

        /* Register hdb-samba4 hooks for use as a keytab */

        kdc->hdb_samba4_context = talloc(kdc, struct hdb_samba4_context);
        if (!kdc->hdb_samba4_context) {
                task_server_terminate(task, "kdc: out of memory", true);
                return; 
        }

        kdc->hdb_samba4_context->ev_ctx = task->event_ctx;
        kdc->hdb_samba4_context->lp_ctx = task->lp_ctx;

        ret = krb5_plugin_register(kdc->smb_krb5_context->krb5_context, 
                                   PLUGIN_TYPE_DATA, "hdb",
                                   &hdb_samba4);
        if(ret) {
                task_server_terminate(task, "kdc: failed to register hdb keytab", true);
                return;
        }

        ret = krb5_kt_register(kdc->smb_krb5_context->krb5_context, &hdb_kt_ops);
        if(ret) {
                task_server_terminate(task, "kdc: failed to register hdb keytab", true);
                return;
        }

        /* Registar WinDC hooks */
        ret = krb5_plugin_register(kdc->smb_krb5_context->krb5_context, 
                                   PLUGIN_TYPE_DATA, "windc",
                                   &windc_plugin_table);
        if(ret) {
                task_server_terminate(task, "kdc: failed to register hdb keytab", true);
                return;
        }

        krb5_kdc_windc_init(kdc->smb_krb5_context->krb5_context);

        /* start listening on the configured network interfaces */
        status = kdc_startup_interfaces(kdc, task->lp_ctx, ifaces);
        if (!NT_STATUS_IS_OK(status)) {
                task_server_terminate(task, "kdc failed to setup interfaces", true);
                return;
        }

        status = IRPC_REGISTER(task->msg_ctx, irpc, KDC_CHECK_GENERIC_KERBEROS, 
                               kdc_check_generic_kerberos, kdc);
        if (!NT_STATUS_IS_OK(status)) {
                task_server_terminate(task, "nbtd failed to setup monitoring", true);
                return;
        }

        irpc_add_name(task->msg_ctx, "kdc_server");
}


/* called at smbd startup - register ourselves as a server service */
NTSTATUS server_service_kdc_init(void)
{
        return register_server_service("kdc", kdc_task_init);
}