source4/kdc/kdc.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 "libcli/util/tstream.h"
  28 #include "lib/messaging/irpc.h"
  29 #include "librpc/gen_ndr/ndr_irpc.h"
  30 #include "librpc/gen_ndr/ndr_krb5pac.h"
  31 #include "lib/stream/packet.h"
  32 #include "lib/socket/netif.h"
  33 #include "param/param.h"
  34 #include "kdc/kdc-glue.h"
  35 #include "dsdb/samdb/samdb.h"
  36 #include "auth/session.h"
  37
  38 extern struct krb5plugin_windc_ftable windc_plugin_table;
  39 extern struct hdb_method hdb_samba4;
  40
  41 static NTSTATUS kdc_proxy_unavailable_error(struct kdc_server *kdc,
  42                                             TALLOC_CTX *mem_ctx,
  43                                             DATA_BLOB *out)
  44 {
  45         int kret;
  46         krb5_data k5_error_blob;
  47
  48         kret = krb5_mk_error(kdc->smb_krb5_context->krb5_context,
  49                              KRB5KDC_ERR_SVC_UNAVAILABLE, NULL, NULL,
  50                              NULL, NULL, NULL, NULL, &k5_error_blob);
  51         if (kret != 0) {
  52                 DEBUG(2,(__location__ ": Unable to form krb5 error reply\n"));
  53                 return NT_STATUS_INTERNAL_ERROR;
  54         }
  55
  56         *out = data_blob_talloc(mem_ctx, k5_error_blob.data, k5_error_blob.length);
  57         krb5_data_free(&k5_error_blob);
  58         if (!out->data) {
  59                 return NT_STATUS_NO_MEMORY;
  60         }
  61
  62         return NT_STATUS_OK;
  63 }
  64
  65 typedef enum kdc_process_ret (*kdc_process_fn_t)(struct kdc_server *kdc,
  66                                                  TALLOC_CTX *mem_ctx,
  67                                                  DATA_BLOB *input,
  68                                                  DATA_BLOB *reply,
  69                                                  struct tsocket_address *peer_addr,
  70                                                  struct tsocket_address *my_addr,
  71                                                  int datagram);
  72
  73 /* hold information about one kdc socket */
  74 struct kdc_socket {
  75         struct kdc_server *kdc;
  76         struct tsocket_address *local_address;
  77         kdc_process_fn_t process;
  78 };
  79
  80 struct kdc_tcp_call {
  81         struct kdc_tcp_connection *kdc_conn;
  82         DATA_BLOB in;
  83         DATA_BLOB out;
  84         uint8_t out_hdr[4];
  85         struct iovec out_iov[2];
  86 };
  87
  88 /*
  89   state of an open tcp connection
  90 */
  91 struct kdc_tcp_connection {
  92         /* stream connection we belong to */
  93         struct stream_connection *conn;
  94
  95         /* the kdc_server the connection belongs to */
  96         struct kdc_socket *kdc_socket;
  97
  98         struct tstream_context *tstream;
  99
 100         struct tevent_queue *send_queue;
 101 };
 102
 103
 104 static void kdc_tcp_terminate_connection(struct kdc_tcp_connection *kdcconn, const char *reason)
 105 {
 106         stream_terminate_connection(kdcconn->conn, reason);
 107 }
 108
 109 static void kdc_tcp_recv(struct stream_connection *conn, uint16_t flags)
 110 {
 111         struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private_data,
 112                                                              struct kdc_tcp_connection);
 113         /* this should never be triggered! */
 114         kdc_tcp_terminate_connection(kdcconn, "kdc_tcp_recv: called");
 115 }
 116
 117 static void kdc_tcp_send(struct stream_connection *conn, uint16_t flags)
 118 {
 119         struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private_data,
 120                                                              struct kdc_tcp_connection);
 121         /* this should never be triggered! */
 122         kdc_tcp_terminate_connection(kdcconn, "kdc_tcp_send: called");
 123 }
 124
 125 /**
 126    Wrapper for krb5_kdc_process_krb5_request, converting to/from Samba
 127    calling conventions
 128 */
 129
 130 static enum kdc_process_ret kdc_process(struct kdc_server *kdc,
 131                                         TALLOC_CTX *mem_ctx,
 132                                         DATA_BLOB *input,
 133                                         DATA_BLOB *reply,
 134                                         struct tsocket_address *peer_addr,
 135                                         struct tsocket_address *my_addr,
 136                                         int datagram_reply)
 137 {
 138         int ret;
 139         char *pa;
 140         struct sockaddr_storage ss;
 141         krb5_data k5_reply;
 142         krb5_data_zero(&k5_reply);
 143
 144         krb5_kdc_update_time(NULL);
 145
 146         ret = tsocket_address_bsd_sockaddr(peer_addr, (struct sockaddr *) &ss,
 147                                 sizeof(struct sockaddr_storage));
 148         if (ret < 0) {
 149                 return KDC_PROCESS_FAILED;
 150         }
 151         pa = tsocket_address_string(peer_addr, mem_ctx);
 152         if (pa == NULL) {
 153                 return KDC_PROCESS_FAILED;
 154         }
 155
 156         DEBUG(10,("Received KDC packet of length %lu from %s\n",
 157                                 (long)input->length - 4, pa));
 158
 159         ret = krb5_kdc_process_krb5_request(kdc->smb_krb5_context->krb5_context,
 160                                             kdc->config,
 161                                             input->data, input->length,
 162                                             &k5_reply,
 163                                             pa,
 164                                             (struct sockaddr *) &ss,
 165                                             datagram_reply);
 166         if (ret == -1) {
 167                 *reply = data_blob(NULL, 0);
 168                 return KDC_PROCESS_FAILED;
 169         }
 170
 171         if (ret == HDB_ERR_NOT_FOUND_HERE) {
 172                 *reply = data_blob(NULL, 0);
 173                 return KDC_PROCESS_PROXY;
 174         }
 175
 176         if (k5_reply.length) {
 177                 *reply = data_blob_talloc(mem_ctx, k5_reply.data, k5_reply.length);
 178                 krb5_data_free(&k5_reply);
 179         } else {
 180                 *reply = data_blob(NULL, 0);
 181         }
 182         return KDC_PROCESS_OK;
 183 }
 184
 185 static void kdc_tcp_call_proxy_done(struct tevent_req *subreq);
 186 static void kdc_tcp_call_writev_done(struct tevent_req *subreq);
 187
 188 static void kdc_tcp_call_loop(struct tevent_req *subreq)
 189 {
 190         struct kdc_tcp_connection *kdc_conn = tevent_req_callback_data(subreq,
 191                                       struct kdc_tcp_connection);
 192         struct kdc_tcp_call *call;
 193         NTSTATUS status;
 194         enum kdc_process_ret ret;
 195
 196         call = talloc(kdc_conn, struct kdc_tcp_call);
 197         if (call == NULL) {
 198                 kdc_tcp_terminate_connection(kdc_conn, "kdc_tcp_call_loop: "
 199                                 "no memory for kdc_tcp_call");
 200                 return;
 201         }
 202         call->kdc_conn = kdc_conn;
 203
 204         status = tstream_read_pdu_blob_recv(subreq,
 205                                             call,
 206                                             &call->in);
 207         TALLOC_FREE(subreq);
 208         if (!NT_STATUS_IS_OK(status)) {
 209                 const char *reason;
 210
 211                 reason = talloc_asprintf(call, "kdc_tcp_call_loop: "
 212                                          "tstream_read_pdu_blob_recv() - %s",
 213                                          nt_errstr(status));
 214                 if (!reason) {
 215                         reason = nt_errstr(status);
 216                 }
 217
 218                 kdc_tcp_terminate_connection(kdc_conn, reason);
 219                 return;
 220         }
 221
 222         DEBUG(10,("Received krb5 TCP packet of length %lu from %s\n",
 223                  (long) call->in.length,
 224                  tsocket_address_string(kdc_conn->conn->remote_address, call)));
 225
 226         /* skip length header */
 227         call->in.data +=4;
 228         call->in.length -= 4;
 229
 230         /* Call krb5 */
 231         ret = kdc_conn->kdc_socket->process(kdc_conn->kdc_socket->kdc,
 232                                            call,
 233                                            &call->in,
 234                                            &call->out,
 235                                            kdc_conn->conn->remote_address,
 236                                            kdc_conn->conn->local_address,
 237                                            0 /* Stream */);
 238         if (ret == KDC_PROCESS_FAILED) {
 239                 kdc_tcp_terminate_connection(kdc_conn,
 240                                 "kdc_tcp_call_loop: process function failed");
 241                 return;
 242         }
 243
 244         if (ret == KDC_PROCESS_PROXY) {
 245                 uint16_t port;
 246
 247                 if (!kdc_conn->kdc_socket->kdc->am_rodc) {
 248                         kdc_tcp_terminate_connection(kdc_conn,
 249                                                      "kdc_tcp_call_loop: proxying requested when not RODC");
 250                         return;
 251                 }
 252                 port = tsocket_address_inet_port(kdc_conn->conn->local_address);
 253
 254                 subreq = kdc_tcp_proxy_send(call,
 255                                             kdc_conn->conn->event.ctx,
 256                                             kdc_conn->kdc_socket->kdc,
 257                                             port,
 258                                             call->in);
 259                 if (subreq == NULL) {
 260                         kdc_tcp_terminate_connection(kdc_conn,
 261                                 "kdc_tcp_call_loop: kdc_tcp_proxy_send failed");
 262                         return;
 263                 }
 264                 tevent_req_set_callback(subreq, kdc_tcp_call_proxy_done, call);
 265                 return;
 266         }
 267
 268         /* First add the length of the out buffer */
 269         RSIVAL(call->out_hdr, 0, call->out.length);
 270         call->out_iov[0].iov_base = (char *) call->out_hdr;
 271         call->out_iov[0].iov_len = 4;
 272
 273         call->out_iov[1].iov_base = (char *) call->out.data;
 274         call->out_iov[1].iov_len = call->out.length;
 275
 276         subreq = tstream_writev_queue_send(call,
 277                                            kdc_conn->conn->event.ctx,
 278                                            kdc_conn->tstream,
 279                                            kdc_conn->send_queue,
 280                                            call->out_iov, 2);
 281         if (subreq == NULL) {
 282                 kdc_tcp_terminate_connection(kdc_conn, "kdc_tcp_call_loop: "
 283                                 "no memory for tstream_writev_queue_send");
 284                 return;
 285         }
 286         tevent_req_set_callback(subreq, kdc_tcp_call_writev_done, call);
 287
 288         /*
 289          * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
 290          * packet_full_request_u32 provides the pdu length then.
 291          */
 292         subreq = tstream_read_pdu_blob_send(kdc_conn,
 293                                             kdc_conn->conn->event.ctx,
 294                                             kdc_conn->tstream,
 295                                             4, /* initial_read_size */
 296                                             packet_full_request_u32,
 297                                             kdc_conn);
 298         if (subreq == NULL) {
 299                 kdc_tcp_terminate_connection(kdc_conn, "kdc_tcp_call_loop: "
 300                                 "no memory for tstream_read_pdu_blob_send");
 301                 return;
 302         }
 303         tevent_req_set_callback(subreq, kdc_tcp_call_loop, kdc_conn);
 304 }
 305
 306 static void kdc_tcp_call_proxy_done(struct tevent_req *subreq)
 307 {
 308         struct kdc_tcp_call *call = tevent_req_callback_data(subreq,
 309                         struct kdc_tcp_call);
 310         struct kdc_tcp_connection *kdc_conn = call->kdc_conn;
 311         NTSTATUS status;
 312
 313         status = kdc_tcp_proxy_recv(subreq, call, &call->out);
 314         TALLOC_FREE(subreq);
 315         if (!NT_STATUS_IS_OK(status)) {
 316                 /* generate an error packet */
 317                 status = kdc_proxy_unavailable_error(kdc_conn->kdc_socket->kdc,
 318                                                      call, &call->out);
 319         }
 320
 321         if (!NT_STATUS_IS_OK(status)) {
 322                 const char *reason;
 323
 324                 reason = talloc_asprintf(call, "kdc_tcp_call_proxy_done: "
 325                                          "kdc_proxy_unavailable_error - %s",
 326                                          nt_errstr(status));
 327                 if (!reason) {
 328                         reason = "kdc_tcp_call_proxy_done: kdc_proxy_unavailable_error() failed";
 329                 }
 330
 331                 kdc_tcp_terminate_connection(call->kdc_conn, reason);
 332                 return;
 333         }
 334
 335         /* First add the length of the out buffer */
 336         RSIVAL(call->out_hdr, 0, call->out.length);
 337         call->out_iov[0].iov_base = (char *) call->out_hdr;
 338         call->out_iov[0].iov_len = 4;
 339
 340         call->out_iov[1].iov_base = (char *) call->out.data;
 341         call->out_iov[1].iov_len = call->out.length;
 342
 343         subreq = tstream_writev_queue_send(call,
 344                                            kdc_conn->conn->event.ctx,
 345                                            kdc_conn->tstream,
 346                                            kdc_conn->send_queue,
 347                                            call->out_iov, 2);
 348         if (subreq == NULL) {
 349                 kdc_tcp_terminate_connection(kdc_conn, "kdc_tcp_call_loop: "
 350                                 "no memory for tstream_writev_queue_send");
 351                 return;
 352         }
 353         tevent_req_set_callback(subreq, kdc_tcp_call_writev_done, call);
 354
 355         /*
 356          * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
 357          * packet_full_request_u32 provides the pdu length then.
 358          */
 359         subreq = tstream_read_pdu_blob_send(kdc_conn,
 360                                             kdc_conn->conn->event.ctx,
 361                                             kdc_conn->tstream,
 362                                             4, /* initial_read_size */
 363                                             packet_full_request_u32,
 364                                             kdc_conn);
 365         if (subreq == NULL) {
 366                 kdc_tcp_terminate_connection(kdc_conn, "kdc_tcp_call_loop: "
 367                                 "no memory for tstream_read_pdu_blob_send");
 368                 return;
 369         }
 370         tevent_req_set_callback(subreq, kdc_tcp_call_loop, kdc_conn);
 371 }
 372
 373 static void kdc_tcp_call_writev_done(struct tevent_req *subreq)
 374 {
 375         struct kdc_tcp_call *call = tevent_req_callback_data(subreq,
 376                         struct kdc_tcp_call);
 377         int sys_errno;
 378         int rc;
 379
 380         rc = tstream_writev_queue_recv(subreq, &sys_errno);
 381         TALLOC_FREE(subreq);
 382         if (rc == -1) {
 383                 const char *reason;
 384
 385                 reason = talloc_asprintf(call, "kdc_tcp_call_writev_done: "
 386                                          "tstream_writev_queue_recv() - %d:%s",
 387                                          sys_errno, strerror(sys_errno));
 388                 if (!reason) {
 389                         reason = "kdc_tcp_call_writev_done: tstream_writev_queue_recv() failed";
 390                 }
 391
 392                 kdc_tcp_terminate_connection(call->kdc_conn, reason);
 393                 return;
 394         }
 395
 396         /* We don't care about errors */
 397
 398         talloc_free(call);
 399 }
 400
 401 /*
 402   called when we get a new connection
 403 */
 404 static void kdc_tcp_accept(struct stream_connection *conn)
 405 {
 406         struct kdc_socket *kdc_socket;
 407         struct kdc_tcp_connection *kdc_conn;
 408         struct tevent_req *subreq;
 409         int rc;
 410
 411         kdc_conn = talloc_zero(conn, struct kdc_tcp_connection);
 412         if (kdc_conn == NULL) {
 413                 stream_terminate_connection(conn,
 414                                 "kdc_tcp_accept: out of memory");
 415                 return;
 416         }
 417
 418         kdc_conn->send_queue = tevent_queue_create(conn, "kdc_tcp_accept");
 419         if (kdc_conn->send_queue == NULL) {
 420                 stream_terminate_connection(conn,
 421                                 "kdc_tcp_accept: out of memory");
 422                 return;
 423         }
 424
 425         kdc_socket = talloc_get_type(conn->private_data, struct kdc_socket);
 426
 427         TALLOC_FREE(conn->event.fde);
 428
 429         rc = tstream_bsd_existing_socket(kdc_conn,
 430                         socket_get_fd(conn->socket),
 431                         &kdc_conn->tstream);
 432         if (rc < 0) {
 433                 stream_terminate_connection(conn,
 434                                 "kdc_tcp_accept: out of memory");
 435                 return;
 436         }
 437
 438         kdc_conn->conn = conn;
 439         kdc_conn->kdc_socket = kdc_socket;
 440         conn->private_data = kdc_conn;
 441
 442         /*
 443          * The krb5 tcp pdu's has the length as 4 byte (initial_read_size),
 444          * packet_full_request_u32 provides the pdu length then.
 445          */
 446         subreq = tstream_read_pdu_blob_send(kdc_conn,
 447                                             kdc_conn->conn->event.ctx,
 448                                             kdc_conn->tstream,
 449                                             4, /* initial_read_size */
 450                                             packet_full_request_u32,
 451                                             kdc_conn);
 452         if (subreq == NULL) {
 453                 kdc_tcp_terminate_connection(kdc_conn, "kdc_tcp_accept: "
 454                                 "no memory for tstream_read_pdu_blob_send");
 455                 return;
 456         }
 457         tevent_req_set_callback(subreq, kdc_tcp_call_loop, kdc_conn);
 458 }
 459
 460 static const struct stream_server_ops kdc_tcp_stream_ops = {
 461         .name                   = "kdc_tcp",
 462         .accept_connection      = kdc_tcp_accept,
 463         .recv_handler           = kdc_tcp_recv,
 464         .send_handler           = kdc_tcp_send
 465 };
 466
 467 /* hold information about one kdc/kpasswd udp socket */
 468 struct kdc_udp_socket {
 469         struct kdc_socket *kdc_socket;
 470         struct tdgram_context *dgram;
 471         struct tevent_queue *send_queue;
 472 };
 473
 474 struct kdc_udp_call {
 475         struct kdc_udp_socket *sock;
 476         struct tsocket_address *src;
 477         DATA_BLOB in;
 478         DATA_BLOB out;
 479 };
 480
 481 static void kdc_udp_call_proxy_done(struct tevent_req *subreq);
 482 static void kdc_udp_call_sendto_done(struct tevent_req *subreq);
 483
 484 static void kdc_udp_call_loop(struct tevent_req *subreq)
 485 {
 486         struct kdc_udp_socket *sock = tevent_req_callback_data(subreq,
 487                                       struct kdc_udp_socket);
 488         struct kdc_udp_call *call;
 489         uint8_t *buf;
 490         ssize_t len;
 491         int sys_errno;
 492         enum kdc_process_ret ret;
 493
 494         call = talloc(sock, struct kdc_udp_call);
 495         if (call == NULL) {
 496                 talloc_free(call);
 497                 goto done;
 498         }
 499         call->sock = sock;
 500
 501         len = tdgram_recvfrom_recv(subreq, &sys_errno,
 502                                    call, &buf, &call->src);
 503         TALLOC_FREE(subreq);
 504         if (len == -1) {
 505                 talloc_free(call);
 506                 goto done;
 507         }
 508
 509         call->in.data = buf;
 510         call->in.length = len;
 511
 512         DEBUG(10,("Received krb5 UDP packet of length %lu from %s\n",
 513                  (long)call->in.length,
 514                  tsocket_address_string(call->src, call)));
 515
 516         /* Call krb5 */
 517         ret = sock->kdc_socket->process(sock->kdc_socket->kdc,
 518                                        call,
 519                                        &call->in,
 520                                        &call->out,
 521                                        call->src,
 522                                        sock->kdc_socket->local_address,
 523                                        1 /* Datagram */);
 524         if (ret == KDC_PROCESS_FAILED) {
 525                 talloc_free(call);
 526                 goto done;
 527         }
 528
 529         if (ret == KDC_PROCESS_PROXY) {
 530                 uint16_t port;
 531
 532                 if (!sock->kdc_socket->kdc->am_rodc) {
 533                         DEBUG(0,("kdc_udp_call_loop: proxying requested when not RODC"));
 534                         talloc_free(call);
 535                         goto done;
 536                 }
 537
 538                 port = tsocket_address_inet_port(sock->kdc_socket->local_address);
 539
 540                 subreq = kdc_udp_proxy_send(call,
 541                                             sock->kdc_socket->kdc->task->event_ctx,
 542                                             sock->kdc_socket->kdc,
 543                                             port,
 544                                             call->in);
 545                 if (subreq == NULL) {
 546                         talloc_free(call);
 547                         goto done;
 548                 }
 549                 tevent_req_set_callback(subreq, kdc_udp_call_proxy_done, call);
 550                 goto done;
 551         }
 552
 553         subreq = tdgram_sendto_queue_send(call,
 554                                           sock->kdc_socket->kdc->task->event_ctx,
 555                                           sock->dgram,
 556                                           sock->send_queue,
 557                                           call->out.data,
 558                                           call->out.length,
 559                                           call->src);
 560         if (subreq == NULL) {
 561                 talloc_free(call);
 562                 goto done;
 563         }
 564         tevent_req_set_callback(subreq, kdc_udp_call_sendto_done, call);
 565
 566 done:
 567         subreq = tdgram_recvfrom_send(sock,
 568                                       sock->kdc_socket->kdc->task->event_ctx,
 569                                       sock->dgram);
 570         if (subreq == NULL) {
 571                 task_server_terminate(sock->kdc_socket->kdc->task,
 572                                       "no memory for tdgram_recvfrom_send",
 573                                       true);
 574                 return;
 575         }
 576         tevent_req_set_callback(subreq, kdc_udp_call_loop, sock);
 577 }
 578
 579 static void kdc_udp_call_proxy_done(struct tevent_req *subreq)
 580 {
 581         struct kdc_udp_call *call =
 582                 tevent_req_callback_data(subreq,
 583                 struct kdc_udp_call);
 584         NTSTATUS status;
 585
 586         status = kdc_udp_proxy_recv(subreq, call, &call->out);
 587         TALLOC_FREE(subreq);
 588         if (!NT_STATUS_IS_OK(status)) {
 589                 /* generate an error packet */
 590                 status = kdc_proxy_unavailable_error(call->sock->kdc_socket->kdc,
 591                                                      call, &call->out);
 592         }
 593
 594         if (!NT_STATUS_IS_OK(status)) {
 595                 talloc_free(call);
 596                 return;
 597         }
 598
 599         subreq = tdgram_sendto_queue_send(call,
 600                                           call->sock->kdc_socket->kdc->task->event_ctx,
 601                                           call->sock->dgram,
 602                                           call->sock->send_queue,
 603                                           call->out.data,
 604                                           call->out.length,
 605                                           call->src);
 606         if (subreq == NULL) {
 607                 talloc_free(call);
 608                 return;
 609         }
 610
 611         tevent_req_set_callback(subreq, kdc_udp_call_sendto_done, call);
 612 }
 613
 614 static void kdc_udp_call_sendto_done(struct tevent_req *subreq)
 615 {
 616         struct kdc_udp_call *call = tevent_req_callback_data(subreq,
 617                                        struct kdc_udp_call);
 618         ssize_t ret;
 619         int sys_errno;
 620
 621         ret = tdgram_sendto_queue_recv(subreq, &sys_errno);
 622
 623         /* We don't care about errors */
 624
 625         talloc_free(call);
 626 }
 627
 628 /*
 629   start listening on the given address
 630 */
 631 static NTSTATUS kdc_add_socket(struct kdc_server *kdc,
 632                                const struct model_ops *model_ops,
 633                                const char *name,
 634                                const char *address,
 635                                uint16_t port,
 636                                kdc_process_fn_t process,
 637                                bool udp_only)
 638 {
 639         struct kdc_socket *kdc_socket;
 640         struct kdc_udp_socket *kdc_udp_socket;
 641         struct tevent_req *udpsubreq;
 642         NTSTATUS status;
 643         int ret;
 644
 645         kdc_socket = talloc(kdc, struct kdc_socket);
 646         NT_STATUS_HAVE_NO_MEMORY(kdc_socket);
 647
 648         kdc_socket->kdc = kdc;
 649         kdc_socket->process = process;
 650
 651         ret = tsocket_address_inet_from_strings(kdc_socket, "ip",
 652                                                 address, port,
 653                                                 &kdc_socket->local_address);
 654         if (ret != 0) {
 655                 status = map_nt_error_from_unix(errno);
 656                 return status;
 657         }
 658
 659         if (!udp_only) {
 660                 status = stream_setup_socket(kdc->task,
 661                                              kdc->task->event_ctx,
 662                                              kdc->task->lp_ctx,
 663                                              model_ops,
 664                                              &kdc_tcp_stream_ops,
 665                                              "ip", address, &port,
 666                                              lpcfg_socket_options(kdc->task->lp_ctx),
 667                                              kdc_socket);
 668                 if (!NT_STATUS_IS_OK(status)) {
 669                         DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
 670                                  address, port, nt_errstr(status)));
 671                         talloc_free(kdc_socket);
 672                         return status;
 673                 }
 674         }
 675
 676         kdc_udp_socket = talloc(kdc_socket, struct kdc_udp_socket);
 677         NT_STATUS_HAVE_NO_MEMORY(kdc_udp_socket);
 678
 679         kdc_udp_socket->kdc_socket = kdc_socket;
 680
 681         ret = tdgram_inet_udp_socket(kdc_socket->local_address,
 682                                      NULL,
 683                                      kdc_udp_socket,
 684                                      &kdc_udp_socket->dgram);
 685         if (ret != 0) {
 686                 status = map_nt_error_from_unix(errno);
 687                 DEBUG(0,("Failed to bind to %s:%u UDP - %s\n",
 688                          address, port, nt_errstr(status)));
 689                 return status;
 690         }
 691
 692         kdc_udp_socket->send_queue = tevent_queue_create(kdc_udp_socket,
 693                                                          "kdc_udp_send_queue");
 694         NT_STATUS_HAVE_NO_MEMORY(kdc_udp_socket->send_queue);
 695
 696         udpsubreq = tdgram_recvfrom_send(kdc_udp_socket,
 697                                          kdc->task->event_ctx,
 698                                          kdc_udp_socket->dgram);
 699         NT_STATUS_HAVE_NO_MEMORY(udpsubreq);
 700         tevent_req_set_callback(udpsubreq, kdc_udp_call_loop, kdc_udp_socket);
 701
 702         return NT_STATUS_OK;
 703 }
 704
 705
 706 /*
 707   setup our listening sockets on the configured network interfaces
 708 */
 709 static NTSTATUS kdc_startup_interfaces(struct kdc_server *kdc, struct loadparm_context *lp_ctx,
 710                                        struct interface *ifaces)
 711 {
 712         const struct model_ops *model_ops;
 713         int num_interfaces;
 714         TALLOC_CTX *tmp_ctx = talloc_new(kdc);
 715         NTSTATUS status;
 716         int i;
 717         uint16_t kdc_port = lpcfg_krb5_port(lp_ctx);
 718         uint16_t kpasswd_port = lpcfg_kpasswd_port(lp_ctx);
 719         bool done_wildcard = false;
 720
 721         /* within the kdc task we want to be a single process, so
 722            ask for the single process model ops and pass these to the
 723            stream_setup_socket() call. */
 724         model_ops = process_model_startup("single");
 725         if (!model_ops) {
 726                 DEBUG(0,("Can't find 'single' process model_ops\n"));
 727                 return NT_STATUS_INTERNAL_ERROR;
 728         }
 729
 730         num_interfaces = iface_count(ifaces);
 731
 732         /* if we are allowing incoming packets from any address, then
 733            we need to bind to the wildcard address */
 734         if (!lpcfg_bind_interfaces_only(lp_ctx)) {
 735                 if (kdc_port) {
 736                         status = kdc_add_socket(kdc, model_ops,
 737                                                 "kdc", "0.0.0.0", kdc_port,
 738                                                 kdc_process, false);
 739                         NT_STATUS_NOT_OK_RETURN(status);
 740                 }
 741
 742                 if (kpasswd_port) {
 743                         status = kdc_add_socket(kdc, model_ops,
 744                                                 "kpasswd", "0.0.0.0", kpasswd_port,
 745                                                 kpasswdd_process, false);
 746                         NT_STATUS_NOT_OK_RETURN(status);
 747                 }
 748                 done_wildcard = true;
 749         }
 750
 751         for (i=0; i<num_interfaces; i++) {
 752                 const char *address = talloc_strdup(tmp_ctx, iface_n_ip(ifaces, i));
 753
 754                 if (kdc_port) {
 755                         status = kdc_add_socket(kdc, model_ops,
 756                                                 "kdc", address, kdc_port,
 757                                                 kdc_process, done_wildcard);
 758                         NT_STATUS_NOT_OK_RETURN(status);
 759                 }
 760
 761                 if (kpasswd_port) {
 762                         status = kdc_add_socket(kdc, model_ops,
 763                                                 "kpasswd", address, kpasswd_port,
 764                                                 kpasswdd_process, done_wildcard);
 765                         NT_STATUS_NOT_OK_RETURN(status);
 766                 }
 767         }
 768
 769         talloc_free(tmp_ctx);
 770
 771         return NT_STATUS_OK;
 772 }
 773
 774
 775 static NTSTATUS kdc_check_generic_kerberos(struct irpc_message *msg,
 776                                  struct kdc_check_generic_kerberos *r)
 777 {
 778         struct PAC_Validate pac_validate;
 779         DATA_BLOB srv_sig;
 780         struct PAC_SIGNATURE_DATA kdc_sig;
 781         struct kdc_server *kdc = talloc_get_type(msg->private_data, struct kdc_server);
 782         enum ndr_err_code ndr_err;
 783         krb5_enctype etype;
 784         int ret;
 785         hdb_entry_ex ent;
 786         krb5_principal principal;
 787         krb5_keyblock keyblock;
 788         Key *key;
 789
 790         /* There is no reply to this request */
 791         r->out.generic_reply = data_blob(NULL, 0);
 792
 793         ndr_err = ndr_pull_struct_blob(&r->in.generic_request, msg, &pac_validate,
 794                                        (ndr_pull_flags_fn_t)ndr_pull_PAC_Validate);
 795         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 796                 return NT_STATUS_INVALID_PARAMETER;
 797         }
 798
 799         if (pac_validate.MessageType != 3) {
 800                 /* We don't implement any other message types - such as certificate validation - yet */
 801                 return NT_STATUS_INVALID_PARAMETER;
 802         }
 803
 804         if (pac_validate.ChecksumAndSignature.length != (pac_validate.ChecksumLength + pac_validate.SignatureLength)
 805             || pac_validate.ChecksumAndSignature.length < pac_validate.ChecksumLength
 806             || pac_validate.ChecksumAndSignature.length < pac_validate.SignatureLength ) {
 807                 return NT_STATUS_INVALID_PARAMETER;
 808         }
 809
 810         srv_sig = data_blob_const(pac_validate.ChecksumAndSignature.data,
 811                                   pac_validate.ChecksumLength);
 812
 813         if (pac_validate.SignatureType == CKSUMTYPE_HMAC_MD5) {
 814                 etype = ETYPE_ARCFOUR_HMAC_MD5;
 815         } else {
 816                 ret = krb5_cksumtype_to_enctype(kdc->smb_krb5_context->krb5_context, pac_validate.SignatureType,
 817                                                 &etype);
 818                 if (ret != 0) {
 819                         return NT_STATUS_LOGON_FAILURE;
 820                 }
 821         }
 822
 823         ret = krb5_make_principal(kdc->smb_krb5_context->krb5_context, &principal,
 824                                   lpcfg_realm(kdc->task->lp_ctx),
 825                                   "krbtgt", lpcfg_realm(kdc->task->lp_ctx),
 826                                   NULL);
 827
 828         if (ret != 0) {
 829                 return NT_STATUS_NO_MEMORY;
 830         }
 831
 832         ret = kdc->config->db[0]->hdb_fetch_kvno(kdc->smb_krb5_context->krb5_context,
 833                                                  kdc->config->db[0],
 834                                                  principal,
 835                                                  HDB_F_GET_KRBTGT | HDB_F_DECRYPT,
 836                                                  0,
 837                                                  &ent);
 838
 839         if (ret != 0) {
 840                 hdb_free_entry(kdc->smb_krb5_context->krb5_context, &ent);
 841                 krb5_free_principal(kdc->smb_krb5_context->krb5_context, principal);
 842
 843                 return NT_STATUS_LOGON_FAILURE;
 844         }
 845
 846         ret = hdb_enctype2key(kdc->smb_krb5_context->krb5_context, &ent.entry, etype, &key);
 847
 848         if (ret != 0) {
 849                 hdb_free_entry(kdc->smb_krb5_context->krb5_context, &ent);
 850                 krb5_free_principal(kdc->smb_krb5_context->krb5_context, principal);
 851                 return NT_STATUS_LOGON_FAILURE;
 852         }
 853
 854         keyblock = key->key;
 855
 856         kdc_sig.type = pac_validate.SignatureType;
 857         kdc_sig.signature = data_blob_const(&pac_validate.ChecksumAndSignature.data[pac_validate.ChecksumLength],
 858                                             pac_validate.SignatureLength);
 859         ret = check_pac_checksum(msg, srv_sig, &kdc_sig,
 860                            kdc->smb_krb5_context->krb5_context, &keyblock);
 861
 862         hdb_free_entry(kdc->smb_krb5_context->krb5_context, &ent);
 863         krb5_free_principal(kdc->smb_krb5_context->krb5_context, principal);
 864
 865         if (ret != 0) {
 866                 return NT_STATUS_LOGON_FAILURE;
 867         }
 868
 869         return NT_STATUS_OK;
 870 }
 871
 872
 873 /*
 874   startup the kdc task
 875 */
 876 static void kdc_task_init(struct task_server *task)
 877 {
 878         struct kdc_server *kdc;
 879         NTSTATUS status;
 880         krb5_error_code ret;
 881         struct interface *ifaces;
 882         int ldb_ret;
 883
 884         switch (lpcfg_server_role(task->lp_ctx)) {
 885         case ROLE_STANDALONE:
 886                 task_server_terminate(task, "kdc: no KDC required in standalone configuration", false);
 887                 return;
 888         case ROLE_DOMAIN_MEMBER:
 889                 task_server_terminate(task, "kdc: no KDC required in member server configuration", false);
 890                 return;
 891         case ROLE_DOMAIN_CONTROLLER:
 892                 /* Yes, we want a KDC */
 893                 break;
 894         }
 895
 896         load_interfaces(task, lpcfg_interfaces(task->lp_ctx), &ifaces);
 897
 898         if (iface_count(ifaces) == 0) {
 899                 task_server_terminate(task, "kdc: no network interfaces configured", false);
 900                 return;
 901         }
 902
 903         task_server_set_title(task, "task[kdc]");
 904
 905         kdc = talloc_zero(task, struct kdc_server);
 906         if (kdc == NULL) {
 907                 task_server_terminate(task, "kdc: out of memory", true);
 908                 return;
 909         }
 910
 911         kdc->task = task;
 912
 913
 914         /* get a samdb connection */
 915         kdc->samdb = samdb_connect(kdc, kdc->task->event_ctx, kdc->task->lp_ctx,
 916                                    system_session(kdc->task->lp_ctx), 0);
 917         if (!kdc->samdb) {
 918                 DEBUG(1,("kdc_task_init: unable to connect to samdb\n"));
 919                 task_server_terminate(task, "kdc: krb5_init_context samdb connect failed", true);
 920                 return;
 921         }
 922
 923         ldb_ret = samdb_rodc(kdc->samdb, &kdc->am_rodc);
 924         if (ldb_ret != LDB_SUCCESS) {
 925                 DEBUG(1, ("kdc_task_init: Cannot determine if we are an RODC: %s\n",
 926                           ldb_errstring(kdc->samdb)));
 927                 task_server_terminate(task, "kdc: krb5_init_context samdb RODC connect failed", true);
 928                 return;
 929         }
 930
 931         kdc->proxy_timeout = lpcfg_parm_int(kdc->task->lp_ctx, NULL, "kdc", "proxy timeout", 5);
 932
 933         initialize_krb5_error_table();
 934
 935         ret = smb_krb5_init_context(kdc, task->event_ctx, task->lp_ctx, &kdc->smb_krb5_context);
 936         if (ret) {
 937                 DEBUG(1,("kdc_task_init: krb5_init_context failed (%s)\n",
 938                          error_message(ret)));
 939                 task_server_terminate(task, "kdc: krb5_init_context failed", true);
 940                 return;
 941         }
 942
 943         krb5_add_et_list(kdc->smb_krb5_context->krb5_context, initialize_hdb_error_table_r);
 944
 945         ret = krb5_kdc_get_config(kdc->smb_krb5_context->krb5_context,
 946                                   &kdc->config);
 947         if(ret) {
 948                 task_server_terminate(task, "kdc: failed to get KDC configuration", true);
 949                 return;
 950         }
 951
 952         kdc->config->logf = kdc->smb_krb5_context->logf;
 953         kdc->config->db = talloc(kdc, struct HDB *);
 954         if (!kdc->config->db) {
 955                 task_server_terminate(task, "kdc: out of memory", true);
 956                 return;
 957         }
 958         kdc->config->num_db = 1;
 959
 960         /* Register hdb-samba4 hooks for use as a keytab */
 961
 962         kdc->base_ctx = talloc_zero(kdc, struct samba_kdc_base_context);
 963         if (!kdc->base_ctx) {
 964                 task_server_terminate(task, "kdc: out of memory", true);
 965                 return;
 966         }
 967
 968         kdc->base_ctx->ev_ctx = task->event_ctx;
 969         kdc->base_ctx->lp_ctx = task->lp_ctx;
 970
 971         status = hdb_samba4_create_kdc(kdc->base_ctx,
 972                                        kdc->smb_krb5_context->krb5_context,
 973                                        &kdc->config->db[0]);
 974         if (!NT_STATUS_IS_OK(status)) {
 975                 task_server_terminate(task, "kdc: hdb_samba4_create_kdc (setup KDC database) failed", true);
 976                 return;
 977         }
 978
 979         ret = krb5_plugin_register(kdc->smb_krb5_context->krb5_context,
 980                                    PLUGIN_TYPE_DATA, "hdb",
 981                                    &hdb_samba4);
 982         if(ret) {
 983                 task_server_terminate(task, "kdc: failed to register hdb plugin", true);
 984                 return;
 985         }
 986
 987         ret = krb5_kt_register(kdc->smb_krb5_context->krb5_context, &hdb_kt_ops);
 988         if(ret) {
 989                 task_server_terminate(task, "kdc: failed to register keytab plugin", true);
 990                 return;
 991         }
 992
 993         /* Register WinDC hooks */
 994         ret = krb5_plugin_register(kdc->smb_krb5_context->krb5_context,
 995                                    PLUGIN_TYPE_DATA, "windc",
 996                                    &windc_plugin_table);
 997         if(ret) {
 998                 task_server_terminate(task, "kdc: failed to register windc plugin", true);
 999                 return;
1000         }
1001
1002         ret = krb5_kdc_windc_init(kdc->smb_krb5_context->krb5_context);
1003
1004         if(ret) {
1005                 task_server_terminate(task, "kdc: failed to init windc plugin", true);
1006                 return;
1007         }
1008
1009         ret = krb5_kdc_pkinit_config(kdc->smb_krb5_context->krb5_context, kdc->config);
1010
1011         if(ret) {
1012                 task_server_terminate(task, "kdc: failed to init kdc pkinit subsystem", true);
1013                 return;
1014         }
1015
1016         /* start listening on the configured network interfaces */
1017         status = kdc_startup_interfaces(kdc, task->lp_ctx, ifaces);
1018         if (!NT_STATUS_IS_OK(status)) {
1019                 task_server_terminate(task, "kdc failed to setup interfaces", true);
1020                 return;
1021         }
1022
1023         status = IRPC_REGISTER(task->msg_ctx, irpc, KDC_CHECK_GENERIC_KERBEROS,
1024                                kdc_check_generic_kerberos, kdc);
1025         if (!NT_STATUS_IS_OK(status)) {
1026                 task_server_terminate(task, "kdc failed to setup monitoring", true);
1027                 return;
1028         }
1029
1030         irpc_add_name(task->msg_ctx, "kdc_server");
1031 }
1032
1033
1034 /* called at smbd startup - register ourselves as a server service */
1035 NTSTATUS server_service_kdc_init(void)
1036 {
1037         return register_server_service("kdc", kdc_task_init);
1038 }