source4/kdc/kdc-heimdal.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    KDC Server startup
   5
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005-2008
   7    Copyright (C) Andrew Tridgell        2005
   8    Copyright (C) Stefan Metzmacher      2005
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "includes.h"
  25 #include "smbd/process_model.h"
  26 #include "lib/tsocket/tsocket.h"
  27 #include "lib/messaging/irpc.h"
  28 #include "librpc/gen_ndr/ndr_irpc.h"
  29 #include "librpc/gen_ndr/ndr_krb5pac.h"
  30 #include "lib/socket/netif.h"
  31 #include "param/param.h"
  32 #include "kdc/kdc-server.h"
  33 #include "kdc/kdc-proxy.h"
  34 #include "kdc/kdc-glue.h"
  35 #include "kdc/pac-glue.h"
  36 #include "kdc/kpasswd-service.h"
  37 #include "dsdb/samdb/samdb.h"
  38 #include "auth/session.h"
  39 #include "libds/common/roles.h"
  40 #include <kdc.h>
  41 #include <hdb.h>
  42
  43 NTSTATUS server_service_kdc_init(TALLOC_CTX *);
  44
  45 extern struct krb5plugin_windc_ftable windc_plugin_table;
  46
  47 /**
  48    Wrapper for krb5_kdc_process_krb5_request, converting to/from Samba
  49    calling conventions
  50 */
  51
  52 static kdc_code kdc_process(struct kdc_server *kdc,
  53                             TALLOC_CTX *mem_ctx,
  54                             DATA_BLOB *input,
  55                             DATA_BLOB *reply,
  56                             struct tsocket_address *peer_addr,
  57                             struct tsocket_address *my_addr,
  58                             int datagram_reply)
  59 {
  60         int ret;
  61         char *pa;
  62         struct sockaddr_storage ss;
  63         krb5_data k5_reply;
  64         krb5_kdc_configuration *kdc_config =
  65                 (krb5_kdc_configuration *)kdc->private_data;
  66
  67         krb5_data_zero(&k5_reply);
  68
  69         krb5_kdc_update_time(NULL);
  70
  71         ret = tsocket_address_bsd_sockaddr(peer_addr, (struct sockaddr *) &ss,
  72                                 sizeof(struct sockaddr_storage));
  73         if (ret < 0) {
  74                 return KDC_ERROR;
  75         }
  76         pa = tsocket_address_string(peer_addr, mem_ctx);
  77         if (pa == NULL) {
  78                 return KDC_ERROR;
  79         }
  80
  81         DEBUG(10,("Received KDC packet of length %lu from %s\n",
  82                                 (long)input->length - 4, pa));
  83
  84         ret = krb5_kdc_process_krb5_request(kdc->smb_krb5_context->krb5_context,
  85                                             kdc_config,
  86                                             input->data, input->length,
  87                                             &k5_reply,
  88                                             pa,
  89                                             (struct sockaddr *) &ss,
  90                                             datagram_reply);
  91         if (ret == -1) {
  92                 *reply = data_blob(NULL, 0);
  93                 return KDC_ERROR;
  94         }
  95
  96         if (ret == HDB_ERR_NOT_FOUND_HERE) {
  97                 *reply = data_blob(NULL, 0);
  98                 return KDC_PROXY_REQUEST;
  99         }
 100
 101         if (k5_reply.length) {
 102                 *reply = data_blob_talloc(mem_ctx, k5_reply.data, k5_reply.length);
 103                 krb5_data_free(&k5_reply);
 104         } else {
 105                 *reply = data_blob(NULL, 0);
 106         }
 107         return KDC_OK;
 108 }
 109
 110 /*
 111   setup our listening sockets on the configured network interfaces
 112 */
 113 static NTSTATUS kdc_startup_interfaces(struct kdc_server *kdc,
 114                                        struct loadparm_context *lp_ctx,
 115                                        struct interface *ifaces,
 116                                        const struct model_ops *model_ops)
 117 {
 118         int num_interfaces;
 119         TALLOC_CTX *tmp_ctx = talloc_new(kdc);
 120         NTSTATUS status;
 121         int i;
 122         uint16_t kdc_port = lpcfg_krb5_port(lp_ctx);
 123         uint16_t kpasswd_port = lpcfg_kpasswd_port(lp_ctx);
 124         bool done_wildcard = false;
 125
 126         num_interfaces = iface_list_count(ifaces);
 127
 128         /* if we are allowing incoming packets from any address, then
 129            we need to bind to the wildcard address */
 130         if (!lpcfg_bind_interfaces_only(lp_ctx)) {
 131                 int num_binds = 0;
 132                 char **wcard = iface_list_wildcard(kdc);
 133                 NT_STATUS_HAVE_NO_MEMORY(wcard);
 134                 for (i=0; wcard[i]; i++) {
 135                         if (kdc_port) {
 136                                 status = kdc_add_socket(kdc, model_ops,
 137                                                         "kdc", wcard[i], kdc_port,
 138                                                         kdc_process, false);
 139                                 if (NT_STATUS_IS_OK(status)) {
 140                                         num_binds++;
 141                                 }
 142                         }
 143
 144                         if (kpasswd_port) {
 145                                 status = kdc_add_socket(kdc, model_ops,
 146                                                         "kpasswd", wcard[i], kpasswd_port,
 147                                                         kpasswd_process, false);
 148                                 if (NT_STATUS_IS_OK(status)) {
 149                                         num_binds++;
 150                                 }
 151                         }
 152                 }
 153                 talloc_free(wcard);
 154                 if (num_binds == 0) {
 155                         return NT_STATUS_INVALID_PARAMETER_MIX;
 156                 }
 157                 done_wildcard = true;
 158         }
 159
 160         for (i=0; i<num_interfaces; i++) {
 161                 const char *address = talloc_strdup(tmp_ctx, iface_list_n_ip(ifaces, i));
 162
 163                 if (kdc_port) {
 164                         status = kdc_add_socket(kdc, model_ops,
 165                                                 "kdc", address, kdc_port,
 166                                                 kdc_process, done_wildcard);
 167                         NT_STATUS_NOT_OK_RETURN(status);
 168                 }
 169
 170                 if (kpasswd_port) {
 171                         status = kdc_add_socket(kdc, model_ops,
 172                                                 "kpasswd", address, kpasswd_port,
 173                                                 kpasswd_process, done_wildcard);
 174                         NT_STATUS_NOT_OK_RETURN(status);
 175                 }
 176         }
 177
 178         talloc_free(tmp_ctx);
 179
 180         return NT_STATUS_OK;
 181 }
 182
 183 static NTSTATUS kdc_check_generic_kerberos(struct irpc_message *msg,
 184                                  struct kdc_check_generic_kerberos *r)
 185 {
 186         struct PAC_Validate pac_validate;
 187         DATA_BLOB srv_sig;
 188         struct PAC_SIGNATURE_DATA kdc_sig;
 189         struct kdc_server *kdc = talloc_get_type(msg->private_data, struct kdc_server);
 190         krb5_kdc_configuration *kdc_config =
 191                 (krb5_kdc_configuration *)kdc->private_data;
 192         enum ndr_err_code ndr_err;
 193         int ret;
 194         hdb_entry_ex ent;
 195         krb5_principal principal;
 196
 197
 198         /* There is no reply to this request */
 199         r->out.generic_reply = data_blob(NULL, 0);
 200
 201         ndr_err = ndr_pull_struct_blob(&r->in.generic_request, msg, &pac_validate,
 202                                        (ndr_pull_flags_fn_t)ndr_pull_PAC_Validate);
 203         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 204                 return NT_STATUS_INVALID_PARAMETER;
 205         }
 206
 207         if (pac_validate.MessageType != NETLOGON_GENERIC_KRB5_PAC_VALIDATE) {
 208                 /* We don't implement any other message types - such as certificate validation - yet */
 209                 return NT_STATUS_INVALID_PARAMETER;
 210         }
 211
 212         if (pac_validate.ChecksumAndSignature.length != (pac_validate.ChecksumLength + pac_validate.SignatureLength)
 213             || pac_validate.ChecksumAndSignature.length < pac_validate.ChecksumLength
 214             || pac_validate.ChecksumAndSignature.length < pac_validate.SignatureLength ) {
 215                 return NT_STATUS_INVALID_PARAMETER;
 216         }
 217
 218         srv_sig = data_blob_const(pac_validate.ChecksumAndSignature.data,
 219                                   pac_validate.ChecksumLength);
 220
 221         ret = krb5_make_principal(kdc->smb_krb5_context->krb5_context, &principal,
 222                                   lpcfg_realm(kdc->task->lp_ctx),
 223                                   "krbtgt", lpcfg_realm(kdc->task->lp_ctx),
 224                                   NULL);
 225
 226         if (ret != 0) {
 227                 return NT_STATUS_NO_MEMORY;
 228         }
 229
 230         ret = kdc_config->db[0]->hdb_fetch_kvno(kdc->smb_krb5_context->krb5_context,
 231                                                  kdc_config->db[0],
 232                                                  principal,
 233                                                  HDB_F_GET_KRBTGT | HDB_F_DECRYPT,
 234                                                  0,
 235                                                  &ent);
 236
 237         if (ret != 0) {
 238                 hdb_free_entry(kdc->smb_krb5_context->krb5_context, &ent);
 239                 krb5_free_principal(kdc->smb_krb5_context->krb5_context, principal);
 240
 241                 return NT_STATUS_LOGON_FAILURE;
 242         }
 243
 244         kdc_sig.type = pac_validate.SignatureType;
 245         kdc_sig.signature = data_blob_const(&pac_validate.ChecksumAndSignature.data[pac_validate.ChecksumLength],
 246                                             pac_validate.SignatureLength);
 247
 248         ret = kdc_check_pac(kdc->smb_krb5_context->krb5_context, srv_sig, &kdc_sig, &ent);
 249
 250         hdb_free_entry(kdc->smb_krb5_context->krb5_context, &ent);
 251         krb5_free_principal(kdc->smb_krb5_context->krb5_context, principal);
 252
 253         if (ret != 0) {
 254                 return NT_STATUS_LOGON_FAILURE;
 255         }
 256
 257         return NT_STATUS_OK;
 258 }
 259
 260
 261 /*
 262   startup the kdc task
 263 */
 264 static void kdc_task_init(struct task_server *task)
 265 {
 266         struct kdc_server *kdc;
 267         krb5_kdc_configuration *kdc_config = NULL;
 268         NTSTATUS status;
 269         krb5_error_code ret;
 270         struct interface *ifaces;
 271         int ldb_ret;
 272
 273         switch (lpcfg_server_role(task->lp_ctx)) {
 274         case ROLE_STANDALONE:
 275                 task_server_terminate(task, "kdc: no KDC required in standalone configuration", false);
 276                 return;
 277         case ROLE_DOMAIN_MEMBER:
 278                 task_server_terminate(task, "kdc: no KDC required in member server configuration", false);
 279                 return;
 280         case ROLE_DOMAIN_PDC:
 281         case ROLE_DOMAIN_BDC:
 282                 task_server_terminate(task, "Cannot start KDC as a 'classic Samba' DC", true);
 283                 return;
 284         case ROLE_ACTIVE_DIRECTORY_DC:
 285                 /* Yes, we want a KDC */
 286                 break;
 287         }
 288
 289         load_interface_list(task, task->lp_ctx, &ifaces);
 290
 291         if (iface_list_count(ifaces) == 0) {
 292                 task_server_terminate(task, "kdc: no network interfaces configured", false);
 293                 return;
 294         }
 295
 296         task_server_set_title(task, "task[kdc]");
 297
 298         kdc = talloc_zero(task, struct kdc_server);
 299         if (kdc == NULL) {
 300                 task_server_terminate(task, "kdc: out of memory", true);
 301                 return;
 302         }
 303
 304         kdc->task = task;
 305
 306
 307         /* get a samdb connection */
 308         kdc->samdb = samdb_connect(kdc, kdc->task->event_ctx, kdc->task->lp_ctx,
 309                                    system_session(kdc->task->lp_ctx), 0);
 310         if (!kdc->samdb) {
 311                 DEBUG(1,("kdc_task_init: unable to connect to samdb\n"));
 312                 task_server_terminate(task, "kdc: krb5_init_context samdb connect failed", true);
 313                 return;
 314         }
 315
 316         ldb_ret = samdb_rodc(kdc->samdb, &kdc->am_rodc);
 317         if (ldb_ret != LDB_SUCCESS) {
 318                 DEBUG(1, ("kdc_task_init: Cannot determine if we are an RODC: %s\n",
 319                           ldb_errstring(kdc->samdb)));
 320                 task_server_terminate(task, "kdc: krb5_init_context samdb RODC connect failed", true);
 321                 return;
 322         }
 323
 324         kdc->proxy_timeout = lpcfg_parm_int(kdc->task->lp_ctx, NULL, "kdc", "proxy timeout", 5);
 325
 326         initialize_krb5_error_table();
 327
 328         ret = smb_krb5_init_context(kdc, task->lp_ctx, &kdc->smb_krb5_context);
 329         if (ret) {
 330                 DEBUG(1,("kdc_task_init: krb5_init_context failed (%s)\n",
 331                          error_message(ret)));
 332                 task_server_terminate(task, "kdc: krb5_init_context failed", true);
 333                 return;
 334         }
 335
 336         krb5_add_et_list(kdc->smb_krb5_context->krb5_context, initialize_hdb_error_table_r);
 337
 338         ret = krb5_kdc_get_config(kdc->smb_krb5_context->krb5_context,
 339                                   &kdc_config);
 340         if(ret) {
 341                 task_server_terminate(task, "kdc: failed to get KDC configuration", true);
 342                 return;
 343         }
 344
 345         kdc_config->logf = (krb5_log_facility *)kdc->smb_krb5_context->pvt_log_data;
 346         kdc_config->db = talloc(kdc, struct HDB *);
 347         if (!kdc_config->db) {
 348                 task_server_terminate(task, "kdc: out of memory", true);
 349                 return;
 350         }
 351         kdc_config->num_db = 1;
 352
 353         /*
 354          * This restores the behavior before
 355          * commit 255e3e18e00f717d99f3bc57c8a8895ff624f3c3
 356          * s4:heimdal: import lorikeet-heimdal-201107150856
 357          * (commit 48936803fae4a2fb362c79365d31f420c917b85b)
 358          *
 359          * as_use_strongest_session_key,preauth_use_strongest_session_key
 360          * and tgs_use_strongest_session_key are input to the
 361          * _kdc_find_etype() function. The old bahavior is in
 362          * the use_strongest_session_key=FALSE code path.
 363          * (The only remaining difference in _kdc_find_etype()
 364          *  is the is_preauth parameter.)
 365          *
 366          * The old behavior in the _kdc_get_preferred_key()
 367          * function is use_strongest_server_key=TRUE.
 368          */
 369         kdc_config->as_use_strongest_session_key = false;
 370         kdc_config->preauth_use_strongest_session_key = false;
 371         kdc_config->tgs_use_strongest_session_key = false;
 372         kdc_config->use_strongest_server_key = true;
 373
 374         kdc_config->autodetect_referrals = false;
 375
 376         /* Register hdb-samba4 hooks for use as a keytab */
 377
 378         kdc->base_ctx = talloc_zero(kdc, struct samba_kdc_base_context);
 379         if (!kdc->base_ctx) {
 380                 task_server_terminate(task, "kdc: out of memory", true);
 381                 return;
 382         }
 383
 384         kdc->base_ctx->ev_ctx = task->event_ctx;
 385         kdc->base_ctx->lp_ctx = task->lp_ctx;
 386         kdc->base_ctx->msg_ctx = task->msg_ctx;
 387
 388         status = hdb_samba4_create_kdc(kdc->base_ctx,
 389                                        kdc->smb_krb5_context->krb5_context,
 390                                        &kdc_config->db[0]);
 391         if (!NT_STATUS_IS_OK(status)) {
 392                 task_server_terminate(task, "kdc: hdb_samba4_create_kdc (setup KDC database) failed", true);
 393                 return;
 394         }
 395
 396         ret = krb5_plugin_register(kdc->smb_krb5_context->krb5_context,
 397                                    PLUGIN_TYPE_DATA, "hdb",
 398                                    &hdb_samba4_interface);
 399         if(ret) {
 400                 task_server_terminate(task, "kdc: failed to register hdb plugin", true);
 401                 return;
 402         }
 403
 404         ret = krb5_kt_register(kdc->smb_krb5_context->krb5_context, &hdb_kt_ops);
 405         if(ret) {
 406                 task_server_terminate(task, "kdc: failed to register keytab plugin", true);
 407                 return;
 408         }
 409
 410         kdc->keytab_name = talloc_asprintf(kdc, "HDB:samba4&%p", kdc->base_ctx);
 411         if (kdc->keytab_name == NULL) {
 412                 task_server_terminate(task,
 413                                       "kdc: Failed to set keytab name",
 414                                       true);
 415                 return;
 416         }
 417
 418         /* Register WinDC hooks */
 419         ret = krb5_plugin_register(kdc->smb_krb5_context->krb5_context,
 420                                    PLUGIN_TYPE_DATA, "windc",
 421                                    &windc_plugin_table);
 422         if(ret) {
 423                 task_server_terminate(task, "kdc: failed to register windc plugin", true);
 424                 return;
 425         }
 426
 427         ret = krb5_kdc_windc_init(kdc->smb_krb5_context->krb5_context);
 428
 429         if(ret) {
 430                 task_server_terminate(task, "kdc: failed to init windc plugin", true);
 431                 return;
 432         }
 433
 434         ret = krb5_kdc_pkinit_config(kdc->smb_krb5_context->krb5_context, kdc_config);
 435
 436         if(ret) {
 437                 task_server_terminate(task, "kdc: failed to init kdc pkinit subsystem", true);
 438                 return;
 439         }
 440         kdc->private_data = kdc_config;
 441
 442         /* start listening on the configured network interfaces */
 443         status = kdc_startup_interfaces(kdc, task->lp_ctx, ifaces,
 444                                         task->model_ops);
 445         if (!NT_STATUS_IS_OK(status)) {
 446                 task_server_terminate(task, "kdc failed to setup interfaces", true);
 447                 return;
 448         }
 449
 450         status = IRPC_REGISTER(task->msg_ctx, irpc, KDC_CHECK_GENERIC_KERBEROS,
 451                                kdc_check_generic_kerberos, kdc);
 452         if (!NT_STATUS_IS_OK(status)) {
 453                 task_server_terminate(task, "kdc failed to setup monitoring", true);
 454                 return;
 455         }
 456
 457         irpc_add_name(task->msg_ctx, "kdc_server");
 458 }
 459
 460
 461 /* called at smbd startup - register ourselves as a server service */
 462 NTSTATUS server_service_kdc_init(TALLOC_CTX *ctx)
 463 {
 464         struct service_details details = {
 465                 .inhibit_fork_on_accept = true,
 466                 /*
 467                  * Need to prevent pre-forking on kdc.
 468                  * The task_init function is run on the master process only
 469                  * and the irpc process name is registered in it's event loop.
 470                  * The child worker processes initialise their event loops on
 471                  * fork, so are not listening for the irpc event.
 472                  *
 473                  * The master process does not wait on that event context
 474                  * the master process is responsible for managing the worker
 475                  * processes not performing work.
 476                  */
 477                 .inhibit_pre_fork = true
 478         };
 479         return register_server_service(ctx, "kdc", kdc_task_init, &details);
 480 }