source4/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 2 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, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24 #include "includes.h"
  25 #include "system/kerberos.h"
  26 #include "auth/kerberos/kerberos.h"
  27 #include "system/network.h"
  28 #include "system/select.h"
  29 #include "system/filesys.h"
  30 #include "lib/socket/socket.h"
  31 #include "lib/events/events.h"
  32
  33 #include "heimdal_build/roken.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         BOOL timeout;
  45         NTSTATUS status;
  46         DATA_BLOB request, reply, partial;
  47
  48         size_t partial_read;
  49
  50         krb5_krbhst_info *hi;
  51 };
  52
  53 static int smb_krb5_context_destroy_1(void *ptr)
  54 {
  55         struct smb_krb5_context *ctx = ptr;
  56         krb5_free_context(ctx->krb5_context);
  57         return 0;
  58 }
  59
  60 static int smb_krb5_context_destroy_2(void *ptr)
  61 {
  62         struct smb_krb5_context *ctx = ptr;
  63
  64         /* Otherwise krb5_free_context will try and close what we have already free()ed */
  65         krb5_set_warn_dest(ctx->krb5_context, NULL);
  66         krb5_closelog(ctx->krb5_context, ctx->logf);
  67         smb_krb5_context_destroy_1(ptr);
  68         return 0;
  69 }
  70
  71 /* We never close down the DEBUG system, and no need to unreference the use */
  72 static void smb_krb5_debug_close(void *private) {
  73         return;
  74 }
  75
  76 static void smb_krb5_debug_wrapper(const char *timestr, const char *msg, void *private)
  77 {
  78         DEBUG(3, ("Kerberos: %s\n", msg));
  79 }
  80
  81 /*
  82   handle recv events on a smb_krb5 socket
  83 */
  84 static void smb_krb5_socket_recv(struct smb_krb5_socket *smb_krb5)
  85 {
  86         TALLOC_CTX *tmp_ctx = talloc_new(smb_krb5);
  87         NTSTATUS status;
  88         DATA_BLOB blob;
  89         size_t nread, dsize;
  90
  91         switch (smb_krb5->hi->proto) {
  92         case KRB5_KRBHST_UDP:
  93                 status = socket_pending(smb_krb5->sock, &dsize);
  94                 if (!NT_STATUS_IS_OK(status)) {
  95                         talloc_free(tmp_ctx);
  96                         return;
  97                 }
  98
  99                 blob = data_blob_talloc(tmp_ctx, NULL, dsize);
 100                 if (blob.data == NULL) {
 101                         talloc_free(tmp_ctx);
 102                         return;
 103                 }
 104
 105                 status = socket_recv(smb_krb5->sock, blob.data, blob.length, &nread, 0);
 106                 if (!NT_STATUS_IS_OK(status)) {
 107                         talloc_free(tmp_ctx);
 108                         return;
 109                 }
 110                 blob.length = nread;
 111
 112                 DEBUG(2,("Received smb_krb5 packet of length %d\n",
 113                          (int)blob.length));
 114
 115                 talloc_steal(smb_krb5, blob.data);
 116                 smb_krb5->reply = blob;
 117                 talloc_free(tmp_ctx);
 118                 break;
 119         case KRB5_KRBHST_TCP:
 120                 if (smb_krb5->partial.length == 0) {
 121                         smb_krb5->partial = data_blob_talloc(smb_krb5, NULL, 4);
 122                         if (!smb_krb5->partial.data) {
 123                                 smb_krb5->status = NT_STATUS_NO_MEMORY;
 124                                 return;
 125                         }
 126
 127                         smb_krb5->partial_read = 0;
 128                 }
 129
 130                 /* read in the packet length */
 131                 if (smb_krb5->partial_read < 4) {
 132                         uint32_t packet_length;
 133
 134                         status = socket_recv(smb_krb5->sock,
 135                                              smb_krb5->partial.data + smb_krb5->partial_read,
 136                                              4 - smb_krb5->partial_read,
 137                                              &nread, 0);
 138                         if (NT_STATUS_IS_ERR(status))  {
 139                                 smb_krb5->status = status;
 140                                 return;
 141                         }
 142                         if (!NT_STATUS_IS_OK(status)) {
 143                                 return;
 144                         }
 145
 146                         smb_krb5->partial_read += nread;
 147                         if (smb_krb5->partial_read != 4) {
 148                                 return;
 149                         }
 150
 151                         packet_length = RIVAL(smb_krb5->partial.data, 0);
 152
 153                         smb_krb5->partial.data = talloc_realloc(smb_krb5, smb_krb5->partial.data,
 154                                                                 uint8_t, packet_length + 4);
 155                         if (!smb_krb5->partial.data)  {
 156                                 smb_krb5->status = NT_STATUS_NO_MEMORY;
 157                                 return;
 158                         }
 159
 160                         smb_krb5->partial.length = packet_length + 4;
 161                 }
 162
 163                 /* read in the body */
 164                 status = socket_recv(smb_krb5->sock,
 165                                      smb_krb5->partial.data + smb_krb5->partial_read,
 166                                      smb_krb5->partial.length - smb_krb5->partial_read,
 167                                      &nread, 0);
 168                 if (NT_STATUS_IS_ERR(status))  {
 169                         smb_krb5->status = status;
 170                         return;
 171                 }
 172                 if (!NT_STATUS_IS_OK(status)) return;
 173
 174                 smb_krb5->partial_read += nread;
 175
 176                 if (smb_krb5->partial_read != smb_krb5->partial.length) return;
 177
 178                 smb_krb5->reply = data_blob_talloc(smb_krb5, smb_krb5->partial.data + 4, smb_krb5->partial.length - 4);
 179                 break;
 180         case KRB5_KRBHST_HTTP:
 181                 return;
 182         }
 183 }
 184
 185 /*
 186   handle request timeouts
 187 */
 188 static void smb_krb5_request_timeout(struct event_context *event_ctx,
 189                                   struct timed_event *te, struct timeval t,
 190                                   void *private)
 191 {
 192         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
 193         DEBUG(5,("Timed out smb_krb5 packet\n"));
 194         smb_krb5->timeout = True;
 195 }
 196
 197 /*
 198   handle send events on a smb_krb5 socket
 199 */
 200 static void smb_krb5_socket_send(struct smb_krb5_socket *smb_krb5)
 201 {
 202         NTSTATUS status;
 203
 204         size_t len;
 205
 206         len = smb_krb5->request.length;
 207         status = socket_send(smb_krb5->sock, &smb_krb5->request, &len, 0);
 208
 209         if (!NT_STATUS_IS_OK(status)) return;
 210
 211         EVENT_FD_READABLE(smb_krb5->fde);
 212
 213         EVENT_FD_NOT_WRITEABLE(smb_krb5->fde);
 214         return;
 215 }
 216
 217
 218 /*
 219   handle fd events on a smb_krb5_socket
 220 */
 221 static void smb_krb5_socket_handler(struct event_context *ev, struct fd_event *fde,
 222                                  uint16_t flags, void *private)
 223 {
 224         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
 225         if (flags & EVENT_FD_WRITE) {
 226                 smb_krb5_socket_send(smb_krb5);
 227         }
 228         if (flags & EVENT_FD_READ) {
 229                 smb_krb5_socket_recv(smb_krb5);
 230         }
 231 }
 232
 233
 234 static krb5_error_code smb_krb5_send_and_recv_func(krb5_context context,
 235                                                    void *data,
 236                                                    krb5_krbhst_info *hi,
 237                                                    const krb5_data *send_buf,
 238                                                    krb5_data *recv_buf)
 239 {
 240         krb5_error_code ret;
 241         NTSTATUS status;
 242         char *remote_addr;
 243         const char *name;
 244         struct addrinfo *ai, *a;
 245         struct smb_krb5_socket *smb_krb5;
 246         int port;
 247
 248         struct event_context *ev = talloc_get_type(data, struct event_context);
 249
 250         DATA_BLOB send_blob = data_blob_const(send_buf->data, send_buf->length);
 251
 252         ret = krb5_krbhst_get_addrinfo(context, hi, &ai);
 253         if (ret) {
 254                 return ret;
 255         }
 256
 257         for (a = ai; a; a = ai->ai_next) {
 258                 smb_krb5 = talloc(NULL, struct smb_krb5_socket);
 259                 if (!smb_krb5) {
 260                         return ENOMEM;
 261                 }
 262                 smb_krb5->hi = hi;
 263
 264                 switch (a->ai_family) {
 265                 case PF_INET:
 266                         name = "ipv4";
 267                         break;
 268                 case PF_INET6:
 269                         name = "ipv6";
 270                         break;
 271                 default:
 272                         talloc_free(smb_krb5);
 273                         return EINVAL;
 274                 }
 275
 276                 status = NT_STATUS_INVALID_PARAMETER;
 277                 switch (hi->proto) {
 278                 case KRB5_KRBHST_UDP:
 279                         if (lp_parm_bool(-1, "krb5", "udp", True)) {
 280                                 status = socket_create(name, SOCKET_TYPE_DGRAM, &smb_krb5->sock, 0);
 281                                 break;
 282                         }
 283                 case KRB5_KRBHST_TCP:
 284                         if (lp_parm_bool(-1, "krb5", "tcp", True)) {
 285                                 status = socket_create(name, SOCKET_TYPE_STREAM, &smb_krb5->sock, 0);
 286                                 break;
 287                         }
 288                 case KRB5_KRBHST_HTTP:
 289                         talloc_free(smb_krb5);
 290                         return EINVAL;
 291                 }
 292                 if (!NT_STATUS_IS_OK(status)) {
 293                         talloc_free(smb_krb5);
 294                         continue;
 295                 }
 296
 297                 talloc_steal(smb_krb5, smb_krb5->sock);
 298
 299                 switch (a->ai_family) {
 300                 case PF_INET:
 301                         remote_addr = talloc_strdup(smb_krb5, inet_ntoa(((struct sockaddr_in *)a->ai_addr)->sin_addr));
 302                         port = ntohs(((struct sockaddr_in *)a->ai_addr)->sin_port);
 303                         break;
 304                 case PF_INET6:
 305                 {
 306                         char addr[128];
 307                         const char *ret_addr;
 308                         ret_addr = inet_ntop(AF_INET6, &((struct sockaddr_in6 *)a->ai_addr)->sin6_addr, addr, sizeof(addr));
 309                         if (ret_addr == NULL) {
 310                                 talloc_free(smb_krb5);
 311                                 return EINVAL;
 312                         }
 313
 314                         remote_addr = talloc_strdup(smb_krb5, ret_addr);
 315                         port = ntohs(((struct sockaddr_in6 *)a->ai_addr)->sin6_port);
 316                         break;
 317                 }
 318                 default:
 319                         talloc_free(smb_krb5);
 320                         return EINVAL;
 321                 }
 322
 323                 status = socket_connect_ev(smb_krb5->sock, NULL, 0, remote_addr, port, 0, ev);
 324                 if (!NT_STATUS_IS_OK(status)) {
 325                         talloc_free(smb_krb5);
 326                         continue;
 327                 }
 328                 talloc_free(remote_addr);
 329
 330                 smb_krb5->fde = event_add_fd(ev, smb_krb5,
 331                                              socket_get_fd(smb_krb5->sock), 0,
 332                                              smb_krb5_socket_handler, smb_krb5);
 333
 334                 event_add_timed(ev, smb_krb5,
 335                                 timeval_current_ofs(context->kdc_timeout, 0),
 336                                 smb_krb5_request_timeout, smb_krb5);
 337
 338                 EVENT_FD_WRITEABLE(smb_krb5->fde);
 339
 340                 switch (hi->proto) {
 341                 case KRB5_KRBHST_UDP:
 342                         smb_krb5->request = send_blob;
 343                         break;
 344                 case KRB5_KRBHST_TCP:
 345                         smb_krb5->request = data_blob_talloc(smb_krb5, NULL, send_blob.length + 4);
 346                         RSIVAL(smb_krb5->request.data, 0, send_blob.length);
 347                         memcpy(smb_krb5->request.data+4, send_blob.data, send_blob.length);
 348                         break;
 349                 case KRB5_KRBHST_HTTP:
 350                         talloc_free(smb_krb5);
 351                         return EINVAL;
 352                 }
 353                 smb_krb5->timeout = False;
 354                 smb_krb5->status = NT_STATUS_OK;
 355                 smb_krb5->reply = data_blob(NULL, 0);
 356                 smb_krb5->partial = data_blob(NULL, 0);
 357
 358                 while (!smb_krb5->timeout && (NT_STATUS_IS_OK(smb_krb5->status)) && !smb_krb5->reply.length) {
 359                         if (event_loop_once(ev) != 0) {
 360                                 talloc_free(smb_krb5);
 361                                 return EINVAL;
 362                         }
 363                 }
 364                 if (!NT_STATUS_IS_OK(smb_krb5->status)) {
 365                         DEBUG(2,("Error reading smb_krb5 reply packet: %s\n", nt_errstr(smb_krb5->status)));
 366                         talloc_free(smb_krb5);
 367                         continue;
 368                 }
 369
 370                 if (smb_krb5->timeout) {
 371                         talloc_free(smb_krb5);
 372                         continue;
 373                 }
 374
 375                 ret = krb5_data_copy(recv_buf, smb_krb5->reply.data, smb_krb5->reply.length);
 376                 if (ret) {
 377                         talloc_free(smb_krb5);
 378                         return ret;
 379                 }
 380                 talloc_free(smb_krb5);
 381
 382                 break;
 383         }
 384         if (a) {
 385                 return 0;
 386         }
 387         return KRB5_KDC_UNREACH;
 388 }
 389
 390 /* NO internal data, so nothing to free */
 391 static void smb_krb5_send_and_recv_close_func(krb5_context context, void *data)
 392 {
 393         return;
 394 }
 395
 396
 397  krb5_error_code smb_krb5_init_context(void *parent_ctx,
 398                                        struct smb_krb5_context **smb_krb5_context)
 399 {
 400         krb5_error_code ret;
 401         TALLOC_CTX *tmp_ctx;
 402         struct event_context *ev;
 403
 404         initialize_krb5_error_table();
 405
 406         tmp_ctx = talloc_new(parent_ctx);
 407         *smb_krb5_context = talloc(tmp_ctx, struct smb_krb5_context);
 408
 409         if (!*smb_krb5_context || !tmp_ctx) {
 410                 talloc_free(*smb_krb5_context);
 411                 talloc_free(tmp_ctx);
 412                 return ENOMEM;
 413         }
 414
 415         ret = krb5_init_context(&(*smb_krb5_context)->krb5_context);
 416         if (ret) {
 417                 DEBUG(1,("krb5_init_context failed (%s)\n",
 418                          error_message(ret)));
 419                 return ret;
 420         }
 421
 422         talloc_set_destructor(*smb_krb5_context, smb_krb5_context_destroy_1);
 423
 424         if (lp_realm() && *lp_realm()) {
 425                 char *upper_realm = strupper_talloc(tmp_ctx, lp_realm());
 426                 if (!upper_realm) {
 427                         DEBUG(1,("gensec_krb5_start: could not uppercase realm: %s\n", lp_realm()));
 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         ev = event_context_find(*smb_krb5_context);
 463         /* Set use of our socket lib */
 464         ret = krb5_set_send_recv_func((*smb_krb5_context)->krb5_context,
 465                                       smb_krb5_send_and_recv_func,
 466                                       smb_krb5_send_and_recv_close_func, ev);
 467         if (ret) {
 468                 DEBUG(1,("krb5_set_send_recv_func failed (%s)\n",
 469                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 470                 talloc_free(tmp_ctx);
 471                 return ret;
 472         }
 473
 474         talloc_steal(parent_ctx, *smb_krb5_context);
 475         talloc_free(tmp_ctx);
 476
 477         /* Set options in kerberos */
 478
 479         (*smb_krb5_context)->krb5_context->fdns = FALSE;
 480
 481         return 0;
 482 }
 483
 484  void smb_krb5_free_context(struct smb_krb5_context *smb_krb5_context)
 485 {
 486         talloc_free(smb_krb5_context);
 487 }