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 #include "libcli/resolve/resolve.h"
  34
  35 /*
  36   context structure for operations on cldap packets
  37 */
  38 struct smb_krb5_socket {
  39         struct socket_context *sock;
  40
  41         /* the fd event */
  42         struct fd_event *fde;
  43
  44         NTSTATUS status;
  45         DATA_BLOB request, reply;
  46
  47         struct packet_context *packet;
  48
  49         size_t partial_read;
  50
  51         krb5_krbhst_info *hi;
  52 };
  53
  54 static int smb_krb5_context_destroy_1(struct smb_krb5_context *ctx)
  55 {
  56         krb5_free_context(ctx->krb5_context);
  57         return 0;
  58 }
  59
  60 static int smb_krb5_context_destroy_2(struct smb_krb5_context *ctx)
  61 {
  62         /* Otherwise krb5_free_context will try and close what we have already free()ed */
  63         krb5_set_warn_dest(ctx->krb5_context, NULL);
  64         krb5_closelog(ctx->krb5_context, ctx->logf);
  65         smb_krb5_context_destroy_1(ctx);
  66         return 0;
  67 }
  68
  69 /* We never close down the DEBUG system, and no need to unreference the use */
  70 static void smb_krb5_debug_close(void *private) {
  71         return;
  72 }
  73
  74 static void smb_krb5_debug_wrapper(const char *timestr, const char *msg, void *private)
  75 {
  76         DEBUG(2, ("Kerberos: %s\n", msg));
  77 }
  78
  79 /*
  80   handle recv events on a smb_krb5 socket
  81 */
  82 static void smb_krb5_socket_recv(struct smb_krb5_socket *smb_krb5)
  83 {
  84         TALLOC_CTX *tmp_ctx = talloc_new(smb_krb5);
  85         DATA_BLOB blob;
  86         size_t nread, dsize;
  87
  88         smb_krb5->status = socket_pending(smb_krb5->sock, &dsize);
  89         if (!NT_STATUS_IS_OK(smb_krb5->status)) {
  90                 talloc_free(tmp_ctx);
  91                 return;
  92         }
  93
  94         blob = data_blob_talloc(tmp_ctx, NULL, dsize);
  95         if (blob.data == NULL && dsize != 0) {
  96                 smb_krb5->status = NT_STATUS_NO_MEMORY;
  97                 talloc_free(tmp_ctx);
  98                 return;
  99         }
 100
 101         smb_krb5->status = socket_recv(smb_krb5->sock, blob.data, blob.length, &nread);
 102         if (!NT_STATUS_IS_OK(smb_krb5->status)) {
 103                 talloc_free(tmp_ctx);
 104                 return;
 105         }
 106         blob.length = nread;
 107
 108         if (nread == 0) {
 109                 smb_krb5->status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
 110                 talloc_free(tmp_ctx);
 111                 return;
 112         }
 113
 114         DEBUG(2,("Received smb_krb5 packet of length %d\n",
 115                  (int)blob.length));
 116
 117         talloc_steal(smb_krb5, blob.data);
 118         smb_krb5->reply = blob;
 119         talloc_free(tmp_ctx);
 120 }
 121
 122 static NTSTATUS smb_krb5_full_packet(void *private, DATA_BLOB data)
 123 {
 124         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
 125         talloc_steal(smb_krb5, data.data);
 126         smb_krb5->reply = data;
 127         smb_krb5->reply.length -= 4;
 128         smb_krb5->reply.data += 4;
 129         return NT_STATUS_OK;
 130 }
 131
 132 /*
 133   handle request timeouts
 134 */
 135 static void smb_krb5_request_timeout(struct event_context *event_ctx,
 136                                   struct timed_event *te, struct timeval t,
 137                                   void *private)
 138 {
 139         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
 140         DEBUG(5,("Timed out smb_krb5 packet\n"));
 141         smb_krb5->status = NT_STATUS_IO_TIMEOUT;
 142 }
 143
 144 static void smb_krb5_error_handler(void *private, NTSTATUS status)
 145 {
 146         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
 147         smb_krb5->status = status;
 148 }
 149
 150 /*
 151   handle send events on a smb_krb5 socket
 152 */
 153 static void smb_krb5_socket_send(struct smb_krb5_socket *smb_krb5)
 154 {
 155         NTSTATUS status;
 156
 157         size_t len;
 158
 159         len = smb_krb5->request.length;
 160         status = socket_send(smb_krb5->sock, &smb_krb5->request, &len);
 161
 162         if (!NT_STATUS_IS_OK(status)) return;
 163
 164         EVENT_FD_READABLE(smb_krb5->fde);
 165
 166         EVENT_FD_NOT_WRITEABLE(smb_krb5->fde);
 167         return;
 168 }
 169
 170
 171 /*
 172   handle fd events on a smb_krb5_socket
 173 */
 174 static void smb_krb5_socket_handler(struct event_context *ev, struct fd_event *fde,
 175                                  uint16_t flags, void *private)
 176 {
 177         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
 178         switch (smb_krb5->hi->proto) {
 179         case KRB5_KRBHST_UDP:
 180                 if (flags & EVENT_FD_READ) {
 181                         smb_krb5_socket_recv(smb_krb5);
 182                         return;
 183                 }
 184                 if (flags & EVENT_FD_WRITE) {
 185                         smb_krb5_socket_send(smb_krb5);
 186                         return;
 187                 }
 188                 /* not reached */
 189                 return;
 190         case KRB5_KRBHST_TCP:
 191                 if (flags & EVENT_FD_READ) {
 192                         packet_recv(smb_krb5->packet);
 193                         return;
 194                 }
 195                 if (flags & EVENT_FD_WRITE) {
 196                         packet_queue_run(smb_krb5->packet);
 197                         return;
 198                 }
 199                 /* not reached */
 200                 return;
 201         case KRB5_KRBHST_HTTP:
 202                 /* can't happen */
 203                 break;
 204         }
 205 }
 206
 207
 208 krb5_error_code smb_krb5_send_and_recv_func(krb5_context context,
 209                                             void *data,
 210                                             krb5_krbhst_info *hi,
 211                                             const krb5_data *send_buf,
 212                                             krb5_data *recv_buf)
 213 {
 214         krb5_error_code ret;
 215         NTSTATUS status;
 216         struct socket_address *remote_addr;
 217         const char *name;
 218         struct addrinfo *ai, *a;
 219         struct smb_krb5_socket *smb_krb5;
 220
 221         struct event_context *ev = talloc_get_type(data, struct event_context);
 222
 223         DATA_BLOB send_blob = data_blob_const(send_buf->data, send_buf->length);
 224
 225         ret = krb5_krbhst_get_addrinfo(context, hi, &ai);
 226         if (ret) {
 227                 return ret;
 228         }
 229
 230         for (a = ai; a; a = ai->ai_next) {
 231                 smb_krb5 = talloc(NULL, struct smb_krb5_socket);
 232                 if (!smb_krb5) {
 233                         return ENOMEM;
 234                 }
 235                 smb_krb5->hi = hi;
 236
 237                 switch (a->ai_family) {
 238                 case PF_INET:
 239                         name = "ipv4";
 240                         break;
 241 #ifdef HAVE_IPV6
 242                 case PF_INET6:
 243                         name = "ipv6";
 244                         break;
 245 #endif
 246                 default:
 247                         talloc_free(smb_krb5);
 248                         return EINVAL;
 249                 }
 250
 251                 status = NT_STATUS_INVALID_PARAMETER;
 252                 switch (hi->proto) {
 253                 case KRB5_KRBHST_UDP:
 254                         if (lp_parm_bool(global_loadparm, NULL, "krb5", "udp", true)) {
 255                                 status = socket_create(name, SOCKET_TYPE_DGRAM, &smb_krb5->sock, 0);
 256                         }
 257                         break;
 258                 case KRB5_KRBHST_TCP:
 259                         if (lp_parm_bool(global_loadparm, NULL, "krb5", "tcp", true)) {
 260                                 status = socket_create(name, SOCKET_TYPE_STREAM, &smb_krb5->sock, 0);
 261                         }
 262                         break;
 263                 case KRB5_KRBHST_HTTP:
 264                         talloc_free(smb_krb5);
 265                         return EINVAL;
 266                 }
 267                 if (!NT_STATUS_IS_OK(status)) {
 268                         talloc_free(smb_krb5);
 269                         continue;
 270                 }
 271
 272                 talloc_steal(smb_krb5, smb_krb5->sock);
 273
 274                 remote_addr = socket_address_from_sockaddr(smb_krb5, a->ai_addr, a->ai_addrlen);
 275                 if (!remote_addr) {
 276                         talloc_free(smb_krb5);
 277                         continue;
 278                 }
 279
 280                 status = socket_connect_ev(smb_krb5->sock, NULL, remote_addr, 0,
 281                                            NULL, ev);
 282                 if (!NT_STATUS_IS_OK(status)) {
 283                         talloc_free(smb_krb5);
 284                         continue;
 285                 }
 286                 talloc_free(remote_addr);
 287
 288                 /* Setup the FDE, start listening for read events
 289                  * from the start (otherwise we may miss a socket
 290                  * drop) and mark as AUTOCLOSE along with the fde */
 291
 292                 /* Ths is equivilant to EVENT_FD_READABLE(smb_krb5->fde) */
 293                 smb_krb5->fde = event_add_fd(ev, smb_krb5->sock,
 294                                              socket_get_fd(smb_krb5->sock),
 295                                              EVENT_FD_READ|EVENT_FD_AUTOCLOSE,
 296                                              smb_krb5_socket_handler, smb_krb5);
 297                 /* its now the job of the event layer to close the socket */
 298                 socket_set_flags(smb_krb5->sock, SOCKET_FLAG_NOCLOSE);
 299
 300                 event_add_timed(ev, smb_krb5,
 301                                 timeval_current_ofs(context->kdc_timeout, 0),
 302                                 smb_krb5_request_timeout, smb_krb5);
 303
 304
 305                 smb_krb5->status = NT_STATUS_OK;
 306                 smb_krb5->reply = data_blob(NULL, 0);
 307
 308                 switch (hi->proto) {
 309                 case KRB5_KRBHST_UDP:
 310                         EVENT_FD_WRITEABLE(smb_krb5->fde);
 311                         smb_krb5->request = send_blob;
 312                         break;
 313                 case KRB5_KRBHST_TCP:
 314
 315                         smb_krb5->packet = packet_init(smb_krb5);
 316                         if (smb_krb5->packet == NULL) {
 317                                 talloc_free(smb_krb5);
 318                                 return ENOMEM;
 319                         }
 320                         packet_set_private(smb_krb5->packet, smb_krb5);
 321                         packet_set_socket(smb_krb5->packet, smb_krb5->sock);
 322                         packet_set_callback(smb_krb5->packet, smb_krb5_full_packet);
 323                         packet_set_full_request(smb_krb5->packet, packet_full_request_u32);
 324                         packet_set_error_handler(smb_krb5->packet, smb_krb5_error_handler);
 325                         packet_set_event_context(smb_krb5->packet, ev);
 326                         packet_set_fde(smb_krb5->packet, smb_krb5->fde);
 327
 328                         smb_krb5->request = data_blob_talloc(smb_krb5, NULL, send_blob.length + 4);
 329                         RSIVAL(smb_krb5->request.data, 0, send_blob.length);
 330                         memcpy(smb_krb5->request.data+4, send_blob.data, send_blob.length);
 331                         packet_send(smb_krb5->packet, smb_krb5->request);
 332                         break;
 333                 case KRB5_KRBHST_HTTP:
 334                         talloc_free(smb_krb5);
 335                         return EINVAL;
 336                 }
 337                 while ((NT_STATUS_IS_OK(smb_krb5->status)) && !smb_krb5->reply.length) {
 338                         if (event_loop_once(ev) != 0) {
 339                                 talloc_free(smb_krb5);
 340                                 return EINVAL;
 341                         }
 342                 }
 343                 if (NT_STATUS_EQUAL(smb_krb5->status, NT_STATUS_IO_TIMEOUT)) {
 344                         talloc_free(smb_krb5);
 345                         continue;
 346                 }
 347
 348                 if (!NT_STATUS_IS_OK(smb_krb5->status)) {
 349                         DEBUG(2,("Error reading smb_krb5 reply packet: %s\n", nt_errstr(smb_krb5->status)));
 350                         talloc_free(smb_krb5);
 351                         continue;
 352                 }
 353
 354                 ret = krb5_data_copy(recv_buf, smb_krb5->reply.data, smb_krb5->reply.length);
 355                 if (ret) {
 356                         talloc_free(smb_krb5);
 357                         return ret;
 358                 }
 359                 talloc_free(smb_krb5);
 360
 361                 break;
 362         }
 363         if (a) {
 364                 return 0;
 365         }
 366         return KRB5_KDC_UNREACH;
 367 }
 368
 369 krb5_error_code smb_krb5_init_context(void *parent_ctx,
 370                                       struct event_context *ev,
 371                                       struct loadparm_context *lp_ctx,
 372                                        struct smb_krb5_context **smb_krb5_context)
 373 {
 374         krb5_error_code ret;
 375         TALLOC_CTX *tmp_ctx;
 376         char **config_files;
 377         const char *config_file;
 378
 379         initialize_krb5_error_table();
 380
 381         tmp_ctx = talloc_new(parent_ctx);
 382         *smb_krb5_context = talloc(tmp_ctx, struct smb_krb5_context);
 383
 384         if (!*smb_krb5_context || !tmp_ctx) {
 385                 talloc_free(tmp_ctx);
 386                 return ENOMEM;
 387         }
 388
 389         ret = krb5_init_context(&(*smb_krb5_context)->krb5_context);
 390         if (ret) {
 391                 DEBUG(1,("krb5_init_context failed (%s)\n",
 392                          error_message(ret)));
 393                 talloc_free(tmp_ctx);
 394                 return ret;
 395         }
 396
 397         talloc_set_destructor(*smb_krb5_context, smb_krb5_context_destroy_1);
 398
 399         config_file = config_path(tmp_ctx, lp_ctx, "krb5.conf");
 400         if (!config_file) {
 401                 talloc_free(tmp_ctx);
 402                 return ENOMEM;
 403         }
 404
 405         /* Use our local krb5.conf file by default */
 406         ret = krb5_prepend_config_files_default(config_file == NULL?"":config_file, &config_files);
 407         if (ret) {
 408                 DEBUG(1,("krb5_prepend_config_files_default failed (%s)\n",
 409                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 410                 talloc_free(tmp_ctx);
 411                 return ret;
 412         }
 413
 414         ret = krb5_set_config_files((*smb_krb5_context)->krb5_context,
 415                                     config_files);
 416         krb5_free_config_files(config_files);
 417         if (ret) {
 418                 DEBUG(1,("krb5_set_config_files failed (%s)\n",
 419                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 420                 talloc_free(tmp_ctx);
 421                 return ret;
 422         }
 423
 424         if (lp_realm(lp_ctx) && *lp_realm(lp_ctx)) {
 425                 char *upper_realm = strupper_talloc(tmp_ctx, lp_realm(lp_ctx));
 426                 if (!upper_realm) {
 427                         DEBUG(1,("gensec_krb5_start: could not uppercase realm: %s\n", lp_realm(lp_ctx)));
 428                         talloc_free(tmp_ctx);
 429                         return ENOMEM;
 430                 }
 431                 ret = krb5_set_default_realm((*smb_krb5_context)->krb5_context, upper_realm);
 432                 if (ret) {
 433                         DEBUG(1,("krb5_set_default_realm failed (%s)\n",
 434                                  smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 435                         talloc_free(tmp_ctx);
 436                         return ret;
 437                 }
 438         }
 439
 440         /* TODO: Should we have a different name here? */
 441         ret = krb5_initlog((*smb_krb5_context)->krb5_context, "Samba", &(*smb_krb5_context)->logf);
 442
 443         if (ret) {
 444                 DEBUG(1,("krb5_initlog failed (%s)\n",
 445                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 446                 talloc_free(tmp_ctx);
 447                 return ret;
 448         }
 449
 450         talloc_set_destructor(*smb_krb5_context, smb_krb5_context_destroy_2);
 451
 452         ret = krb5_addlog_func((*smb_krb5_context)->krb5_context, (*smb_krb5_context)->logf, 0 /* min */, -1 /* max */,
 453                                smb_krb5_debug_wrapper, smb_krb5_debug_close, NULL);
 454         if (ret) {
 455                 DEBUG(1,("krb5_addlog_func failed (%s)\n",
 456                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 457                 talloc_free(tmp_ctx);
 458                 return ret;
 459         }
 460         krb5_set_warn_dest((*smb_krb5_context)->krb5_context, (*smb_krb5_context)->logf);
 461
 462         /* Set use of our socket lib */
 463         ret = krb5_set_send_to_kdc_func((*smb_krb5_context)->krb5_context,
 464                                         smb_krb5_send_and_recv_func,
 465                                         ev);
 466         if (ret) {
 467                 DEBUG(1,("krb5_set_send_recv_func failed (%s)\n",
 468                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 469                 talloc_free(tmp_ctx);
 470                 return ret;
 471         }
 472
 473         talloc_steal(parent_ctx, *smb_krb5_context);
 474         talloc_free(tmp_ctx);
 475
 476         /* Set options in kerberos */
 477
 478         krb5_set_dns_canonicalize_hostname((*smb_krb5_context)->krb5_context,
 479                                            lp_parm_bool(lp_ctx, NULL, "krb5", "set_dns_canonicalize", false));
 480
 481         return 0;
 482 }
 483