source/auth/kerberos/krb5_init_context.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Wrapper for krb5_init_context
   4
   5    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
   6    Copyright (C) Andrew Tridgell 2005
   7    Copyright (C) Stefan Metzmacher 2004
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "includes.h"
  24 #include "system/kerberos.h"
  25 #include "heimdal/lib/krb5/krb5_locl.h"
  26 #include "auth/kerberos/kerberos.h"
  27 #include "lib/socket/socket.h"
  28 #include "lib/stream/packet.h"
  29 #include "system/network.h"
  30 #include "lib/events/events.h"
  31 #include "roken.h"
  32 #include "param/param.h"
  33
  34 /*
  35   context structure for operations on cldap packets
  36 */
  37 struct smb_krb5_socket {
  38         struct socket_context *sock;
  39
  40         /* the fd event */
  41         struct fd_event *fde;
  42
  43         NTSTATUS status;
  44         DATA_BLOB request, reply;
  45
  46         struct packet_context *packet;
  47
  48         size_t partial_read;
  49
  50         krb5_krbhst_info *hi;
  51 };
  52
  53 static int smb_krb5_context_destroy_1(struct smb_krb5_context *ctx)
  54 {
  55         krb5_free_context(ctx->krb5_context);
  56         return 0;
  57 }
  58
  59 static int smb_krb5_context_destroy_2(struct smb_krb5_context *ctx)
  60 {
  61         /* Otherwise krb5_free_context will try and close what we have already free()ed */
  62         krb5_set_warn_dest(ctx->krb5_context, NULL);
  63         krb5_closelog(ctx->krb5_context, ctx->logf);
  64         smb_krb5_context_destroy_1(ctx);
  65         return 0;
  66 }
  67
  68 /* We never close down the DEBUG system, and no need to unreference the use */
  69 static void smb_krb5_debug_close(void *private) {
  70         return;
  71 }
  72
  73 static void smb_krb5_debug_wrapper(const char *timestr, const char *msg, void *private)
  74 {
  75         DEBUG(2, ("Kerberos: %s\n", msg));
  76 }
  77
  78 /*
  79   handle recv events on a smb_krb5 socket
  80 */
  81 static void smb_krb5_socket_recv(struct smb_krb5_socket *smb_krb5)
  82 {
  83         TALLOC_CTX *tmp_ctx = talloc_new(smb_krb5);
  84         DATA_BLOB blob;
  85         size_t nread, dsize;
  86
  87         smb_krb5->status = socket_pending(smb_krb5->sock, &dsize);
  88         if (!NT_STATUS_IS_OK(smb_krb5->status)) {
  89                 talloc_free(tmp_ctx);
  90                 return;
  91         }
  92
  93         blob = data_blob_talloc(tmp_ctx, NULL, dsize);
  94         if (blob.data == NULL && dsize != 0) {
  95                 smb_krb5->status = NT_STATUS_NO_MEMORY;
  96                 talloc_free(tmp_ctx);
  97                 return;
  98         }
  99
 100         smb_krb5->status = socket_recv(smb_krb5->sock, blob.data, blob.length, &nread);
 101         if (!NT_STATUS_IS_OK(smb_krb5->status)) {
 102                 talloc_free(tmp_ctx);
 103                 return;
 104         }
 105         blob.length = nread;
 106
 107         if (nread == 0) {
 108                 smb_krb5->status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
 109                 talloc_free(tmp_ctx);
 110                 return;
 111         }
 112
 113         DEBUG(2,("Received smb_krb5 packet of length %d\n",
 114                  (int)blob.length));
 115
 116         talloc_steal(smb_krb5, blob.data);
 117         smb_krb5->reply = blob;
 118         talloc_free(tmp_ctx);
 119 }
 120
 121 static NTSTATUS smb_krb5_full_packet(void *private, DATA_BLOB data)
 122 {
 123         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
 124         talloc_steal(smb_krb5, data.data);
 125         smb_krb5->reply = data;
 126         smb_krb5->reply.length -= 4;
 127         smb_krb5->reply.data += 4;
 128         return NT_STATUS_OK;
 129 }
 130
 131 /*
 132   handle request timeouts
 133 */
 134 static void smb_krb5_request_timeout(struct event_context *event_ctx,
 135                                   struct timed_event *te, struct timeval t,
 136                                   void *private)
 137 {
 138         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
 139         DEBUG(5,("Timed out smb_krb5 packet\n"));
 140         smb_krb5->status = NT_STATUS_IO_TIMEOUT;
 141 }
 142
 143 static void smb_krb5_error_handler(void *private, NTSTATUS status)
 144 {
 145         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
 146         smb_krb5->status = status;
 147 }
 148
 149 /*
 150   handle send events on a smb_krb5 socket
 151 */
 152 static void smb_krb5_socket_send(struct smb_krb5_socket *smb_krb5)
 153 {
 154         NTSTATUS status;
 155
 156         size_t len;
 157
 158         len = smb_krb5->request.length;
 159         status = socket_send(smb_krb5->sock, &smb_krb5->request, &len);
 160
 161         if (!NT_STATUS_IS_OK(status)) return;
 162
 163         EVENT_FD_READABLE(smb_krb5->fde);
 164
 165         EVENT_FD_NOT_WRITEABLE(smb_krb5->fde);
 166         return;
 167 }
 168
 169
 170 /*
 171   handle fd events on a smb_krb5_socket
 172 */
 173 static void smb_krb5_socket_handler(struct event_context *ev, struct fd_event *fde,
 174                                  uint16_t flags, void *private)
 175 {
 176         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
 177         switch (smb_krb5->hi->proto) {
 178         case KRB5_KRBHST_UDP:
 179                 if (flags & EVENT_FD_READ) {
 180                         smb_krb5_socket_recv(smb_krb5);
 181                         return;
 182                 }
 183                 if (flags & EVENT_FD_WRITE) {
 184                         smb_krb5_socket_send(smb_krb5);
 185                         return;
 186                 }
 187                 /* not reached */
 188                 return;
 189         case KRB5_KRBHST_TCP:
 190                 if (flags & EVENT_FD_READ) {
 191                         packet_recv(smb_krb5->packet);
 192                         return;
 193                 }
 194                 if (flags & EVENT_FD_WRITE) {
 195                         packet_queue_run(smb_krb5->packet);
 196                         return;
 197                 }
 198                 /* not reached */
 199                 return;
 200         case KRB5_KRBHST_HTTP:
 201                 /* can't happen */
 202                 break;
 203         }
 204 }
 205
 206
 207 krb5_error_code smb_krb5_send_and_recv_func(krb5_context context,
 208                                             void *data,
 209                                             krb5_krbhst_info *hi,
 210                                             const krb5_data *send_buf,
 211                                             krb5_data *recv_buf)
 212 {
 213         krb5_error_code ret;
 214         NTSTATUS status;
 215         struct socket_address *remote_addr;
 216         const char *name;
 217         struct addrinfo *ai, *a;
 218         struct smb_krb5_socket *smb_krb5;
 219
 220         struct event_context *ev = talloc_get_type(data, struct event_context);
 221
 222         DATA_BLOB send_blob = data_blob_const(send_buf->data, send_buf->length);
 223
 224         ret = krb5_krbhst_get_addrinfo(context, hi, &ai);
 225         if (ret) {
 226                 return ret;
 227         }
 228
 229         for (a = ai; a; a = ai->ai_next) {
 230                 smb_krb5 = talloc(NULL, struct smb_krb5_socket);
 231                 if (!smb_krb5) {
 232                         return ENOMEM;
 233                 }
 234                 smb_krb5->hi = hi;
 235
 236                 switch (a->ai_family) {
 237                 case PF_INET:
 238                         name = "ipv4";
 239                         break;
 240 #ifdef HAVE_IPV6
 241                 case PF_INET6:
 242                         name = "ipv6";
 243                         break;
 244 #endif
 245                 default:
 246                         talloc_free(smb_krb5);
 247                         return EINVAL;
 248                 }
 249
 250                 status = NT_STATUS_INVALID_PARAMETER;
 251                 switch (hi->proto) {
 252                 case KRB5_KRBHST_UDP:
 253                         if (lp_parm_bool(global_loadparm, NULL, "krb5", "udp", true)) {
 254                                 status = socket_create(name, SOCKET_TYPE_DGRAM, &smb_krb5->sock, 0);
 255                         }
 256                         break;
 257                 case KRB5_KRBHST_TCP:
 258                         if (lp_parm_bool(global_loadparm, NULL, "krb5", "tcp", true)) {
 259                                 status = socket_create(name, SOCKET_TYPE_STREAM, &smb_krb5->sock, 0);
 260                         }
 261                         break;
 262                 case KRB5_KRBHST_HTTP:
 263                         talloc_free(smb_krb5);
 264                         return EINVAL;
 265                 }
 266                 if (!NT_STATUS_IS_OK(status)) {
 267                         talloc_free(smb_krb5);
 268                         continue;
 269                 }
 270
 271                 talloc_steal(smb_krb5, smb_krb5->sock);
 272
 273                 remote_addr = socket_address_from_sockaddr(smb_krb5, a->ai_addr, a->ai_addrlen);
 274                 if (!remote_addr) {
 275                         talloc_free(smb_krb5);
 276                         continue;
 277                 }
 278
 279                 status = socket_connect_ev(smb_krb5->sock, NULL, remote_addr, 0, ev);
 280                 if (!NT_STATUS_IS_OK(status)) {
 281                         talloc_free(smb_krb5);
 282                         continue;
 283                 }
 284                 talloc_free(remote_addr);
 285
 286                 /* Setup the FDE, start listening for read events
 287                  * from the start (otherwise we may miss a socket
 288                  * drop) and mark as AUTOCLOSE along with the fde */
 289
 290                 /* Ths is equivilant to EVENT_FD_READABLE(smb_krb5->fde) */
 291                 smb_krb5->fde = event_add_fd(ev, smb_krb5->sock,
 292                                              socket_get_fd(smb_krb5->sock),
 293                                              EVENT_FD_READ|EVENT_FD_AUTOCLOSE,
 294                                              smb_krb5_socket_handler, smb_krb5);
 295                 /* its now the job of the event layer to close the socket */
 296                 socket_set_flags(smb_krb5->sock, SOCKET_FLAG_NOCLOSE);
 297
 298                 event_add_timed(ev, smb_krb5,
 299                                 timeval_current_ofs(context->kdc_timeout, 0),
 300                                 smb_krb5_request_timeout, smb_krb5);
 301
 302
 303                 smb_krb5->status = NT_STATUS_OK;
 304                 smb_krb5->reply = data_blob(NULL, 0);
 305
 306                 switch (hi->proto) {
 307                 case KRB5_KRBHST_UDP:
 308                         EVENT_FD_WRITEABLE(smb_krb5->fde);
 309                         smb_krb5->request = send_blob;
 310                         break;
 311                 case KRB5_KRBHST_TCP:
 312
 313                         smb_krb5->packet = packet_init(smb_krb5);
 314                         if (smb_krb5->packet == NULL) {
 315                                 talloc_free(smb_krb5);
 316                                 return ENOMEM;
 317                         }
 318                         packet_set_private(smb_krb5->packet, smb_krb5);
 319                         packet_set_socket(smb_krb5->packet, smb_krb5->sock);
 320                         packet_set_callback(smb_krb5->packet, smb_krb5_full_packet);
 321                         packet_set_full_request(smb_krb5->packet, packet_full_request_u32);
 322                         packet_set_error_handler(smb_krb5->packet, smb_krb5_error_handler);
 323                         packet_set_event_context(smb_krb5->packet, ev);
 324                         packet_set_fde(smb_krb5->packet, smb_krb5->fde);
 325
 326                         smb_krb5->request = data_blob_talloc(smb_krb5, NULL, send_blob.length + 4);
 327                         RSIVAL(smb_krb5->request.data, 0, send_blob.length);
 328                         memcpy(smb_krb5->request.data+4, send_blob.data, send_blob.length);
 329                         packet_send(smb_krb5->packet, smb_krb5->request);
 330                         break;
 331                 case KRB5_KRBHST_HTTP:
 332                         talloc_free(smb_krb5);
 333                         return EINVAL;
 334                 }
 335                 while ((NT_STATUS_IS_OK(smb_krb5->status)) && !smb_krb5->reply.length) {
 336                         if (event_loop_once(ev) != 0) {
 337                                 talloc_free(smb_krb5);
 338                                 return EINVAL;
 339                         }
 340                 }
 341                 if (NT_STATUS_EQUAL(smb_krb5->status, NT_STATUS_IO_TIMEOUT)) {
 342                         talloc_free(smb_krb5);
 343                         continue;
 344                 }
 345
 346                 if (!NT_STATUS_IS_OK(smb_krb5->status)) {
 347                         DEBUG(2,("Error reading smb_krb5 reply packet: %s\n", nt_errstr(smb_krb5->status)));
 348                         talloc_free(smb_krb5);
 349                         continue;
 350                 }
 351
 352                 ret = krb5_data_copy(recv_buf, smb_krb5->reply.data, smb_krb5->reply.length);
 353                 if (ret) {
 354                         talloc_free(smb_krb5);
 355                         return ret;
 356                 }
 357                 talloc_free(smb_krb5);
 358
 359                 break;
 360         }
 361         if (a) {
 362                 return 0;
 363         }
 364         return KRB5_KDC_UNREACH;
 365 }
 366
 367 krb5_error_code smb_krb5_init_context(void *parent_ctx,
 368                                       struct event_context *ev,
 369                                       struct loadparm_context *lp_ctx,
 370                                        struct smb_krb5_context **smb_krb5_context)
 371 {
 372         krb5_error_code ret;
 373         TALLOC_CTX *tmp_ctx;
 374         char **config_files;
 375         const char *config_file;
 376
 377         initialize_krb5_error_table();
 378
 379         tmp_ctx = talloc_new(parent_ctx);
 380         *smb_krb5_context = talloc(tmp_ctx, struct smb_krb5_context);
 381
 382         if (!*smb_krb5_context || !tmp_ctx) {
 383                 talloc_free(tmp_ctx);
 384                 return ENOMEM;
 385         }
 386
 387         ret = krb5_init_context(&(*smb_krb5_context)->krb5_context);
 388         if (ret) {
 389                 DEBUG(1,("krb5_init_context failed (%s)\n",
 390                          error_message(ret)));
 391                 talloc_free(tmp_ctx);
 392                 return ret;
 393         }
 394
 395         talloc_set_destructor(*smb_krb5_context, smb_krb5_context_destroy_1);
 396
 397         config_file = config_path(tmp_ctx, lp_ctx, "krb5.conf");
 398         if (!config_file) {
 399                 talloc_free(tmp_ctx);
 400                 return ENOMEM;
 401         }
 402
 403         /* Use our local krb5.conf file by default */
 404         ret = krb5_prepend_config_files_default(config_file, &config_files);
 405         if (ret) {
 406                 DEBUG(1,("krb5_prepend_config_files_default failed (%s)\n",
 407                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 408                 talloc_free(tmp_ctx);
 409                 return ret;
 410         }
 411
 412         ret = krb5_set_config_files((*smb_krb5_context)->krb5_context,
 413                                     config_files);
 414         krb5_free_config_files(config_files);
 415         if (ret) {
 416                 DEBUG(1,("krb5_set_config_files failed (%s)\n",
 417                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 418                 talloc_free(tmp_ctx);
 419                 return ret;
 420         }
 421
 422         if (lp_realm(lp_ctx) && *lp_realm(lp_ctx)) {
 423                 char *upper_realm = strupper_talloc(tmp_ctx, lp_realm(lp_ctx));
 424                 if (!upper_realm) {
 425                         DEBUG(1,("gensec_krb5_start: could not uppercase realm: %s\n", lp_realm(lp_ctx)));
 426                         talloc_free(tmp_ctx);
 427                         return ENOMEM;
 428                 }
 429                 ret = krb5_set_default_realm((*smb_krb5_context)->krb5_context, upper_realm);
 430                 if (ret) {
 431                         DEBUG(1,("krb5_set_default_realm failed (%s)\n",
 432                                  smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 433                         talloc_free(tmp_ctx);
 434                         return ret;
 435                 }
 436         }
 437
 438         /* TODO: Should we have a different name here? */
 439         ret = krb5_initlog((*smb_krb5_context)->krb5_context, "Samba", &(*smb_krb5_context)->logf);
 440
 441         if (ret) {
 442                 DEBUG(1,("krb5_initlog failed (%s)\n",
 443                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 444                 talloc_free(tmp_ctx);
 445                 return ret;
 446         }
 447
 448         talloc_set_destructor(*smb_krb5_context, smb_krb5_context_destroy_2);
 449
 450         ret = krb5_addlog_func((*smb_krb5_context)->krb5_context, (*smb_krb5_context)->logf, 0 /* min */, -1 /* max */,
 451                                smb_krb5_debug_wrapper, smb_krb5_debug_close, NULL);
 452         if (ret) {
 453                 DEBUG(1,("krb5_addlog_func failed (%s)\n",
 454                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 455                 talloc_free(tmp_ctx);
 456                 return ret;
 457         }
 458         krb5_set_warn_dest((*smb_krb5_context)->krb5_context, (*smb_krb5_context)->logf);
 459
 460         /* Set use of our socket lib */
 461         ret = krb5_set_send_to_kdc_func((*smb_krb5_context)->krb5_context,
 462                                         smb_krb5_send_and_recv_func,
 463                                         ev);
 464         if (ret) {
 465                 DEBUG(1,("krb5_set_send_recv_func failed (%s)\n",
 466                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 467                 talloc_free(tmp_ctx);
 468                 return ret;
 469         }
 470
 471         talloc_steal(parent_ctx, *smb_krb5_context);
 472         talloc_free(tmp_ctx);
 473
 474         /* Set options in kerberos */
 475
 476         krb5_set_dns_canonicalize_hostname((*smb_krb5_context)->krb5_context,
 477                                            lp_parm_bool(lp_ctx, NULL, "krb5", "set_dns_canonicalize", false));
 478
 479         return 0;
 480 }
 481