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 "lib/socket/socket.h"
  28 #include "lib/events/events.h"
  29
  30 /*
  31   context structure for operations on cldap packets
  32 */
  33 struct smb_krb5_socket {
  34         struct socket_context *sock;
  35
  36         /* the fd event */
  37         struct fd_event *fde;
  38
  39         BOOL timeout;
  40         NTSTATUS status;
  41         DATA_BLOB request, reply, partial;
  42
  43         size_t partial_read;
  44
  45         krb5_krbhst_info *hi;
  46 };
  47
  48 static int smb_krb5_context_destroy_1(void *ptr)
  49 {
  50         struct smb_krb5_context *ctx = ptr;
  51         krb5_free_context(ctx->krb5_context);
  52         return 0;
  53 }
  54
  55 static int smb_krb5_context_destroy_2(void *ptr)
  56 {
  57         struct smb_krb5_context *ctx = ptr;
  58
  59         /* Otherwise krb5_free_context will try and close what we have already free()ed */
  60         krb5_set_warn_dest(ctx->krb5_context, NULL);
  61         krb5_closelog(ctx->krb5_context, ctx->logf);
  62         smb_krb5_context_destroy_1(ptr);
  63         return 0;
  64 }
  65
  66 /* We never close down the DEBUG system, and no need to unreference the use */
  67 static void smb_krb5_debug_close(void *private) {
  68         return;
  69 }
  70
  71 static void smb_krb5_debug_wrapper(const char *timestr, const char *msg, void *private)
  72 {
  73         DEBUG(3, ("Kerberos: %s\n", msg));
  74 }
  75
  76 /*
  77   handle recv events on a smb_krb5 socket
  78 */
  79 static void smb_krb5_socket_recv(struct smb_krb5_socket *smb_krb5)
  80 {
  81         TALLOC_CTX *tmp_ctx = talloc_new(smb_krb5);
  82         DATA_BLOB blob;
  83         size_t nread, dsize;
  84
  85         switch (smb_krb5->hi->proto) {
  86         case KRB5_KRBHST_UDP:
  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, 0);
 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                 break;
 120         case KRB5_KRBHST_TCP:
 121                 if (smb_krb5->partial.length == 0) {
 122                         smb_krb5->partial = data_blob_talloc(smb_krb5, NULL, 4);
 123                         if (!smb_krb5->partial.data) {
 124                                 smb_krb5->status = NT_STATUS_NO_MEMORY;
 125                                 return;
 126                         }
 127
 128                         smb_krb5->partial_read = 0;
 129                 }
 130
 131                 /* read in the packet length */
 132                 if (smb_krb5->partial_read < 4) {
 133                         uint32_t packet_length;
 134
 135                         smb_krb5->status = socket_recv(smb_krb5->sock,
 136                                              smb_krb5->partial.data + smb_krb5->partial_read,
 137                                              4 - smb_krb5->partial_read,
 138                                              &nread, 0);
 139                         /* todo: this should be converted to the packet_*() routines */
 140                         if (!NT_STATUS_IS_OK(smb_krb5->status)) {
 141                                 return;
 142                         }
 143
 144                         smb_krb5->partial_read += nread;
 145                         if (smb_krb5->partial_read != 4) {
 146                                 return;
 147                         }
 148
 149                         packet_length = RIVAL(smb_krb5->partial.data, 0);
 150
 151                         smb_krb5->partial.data = talloc_realloc(smb_krb5, smb_krb5->partial.data,
 152                                                                 uint8_t, packet_length + 4);
 153                         if (!smb_krb5->partial.data)  {
 154                                 smb_krb5->status = NT_STATUS_NO_MEMORY;
 155                                 return;
 156                         }
 157
 158                         smb_krb5->partial.length = packet_length + 4;
 159                 }
 160
 161                 /* read in the body */
 162                 smb_krb5->status = socket_recv(smb_krb5->sock,
 163                                      smb_krb5->partial.data + smb_krb5->partial_read,
 164                                      smb_krb5->partial.length - smb_krb5->partial_read,
 165                                      &nread, 0);
 166                 if (!NT_STATUS_IS_OK(smb_krb5->status)) return;
 167
 168                 smb_krb5->partial_read += nread;
 169
 170                 if (smb_krb5->partial_read != smb_krb5->partial.length) return;
 171
 172                 smb_krb5->reply = data_blob_talloc(smb_krb5, smb_krb5->partial.data + 4, smb_krb5->partial.length - 4);
 173                 break;
 174         case KRB5_KRBHST_HTTP:
 175                 return;
 176         }
 177 }
 178
 179 /*
 180   handle request timeouts
 181 */
 182 static void smb_krb5_request_timeout(struct event_context *event_ctx,
 183                                   struct timed_event *te, struct timeval t,
 184                                   void *private)
 185 {
 186         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
 187         DEBUG(5,("Timed out smb_krb5 packet\n"));
 188         smb_krb5->timeout = True;
 189 }
 190
 191 /*
 192   handle send events on a smb_krb5 socket
 193 */
 194 static void smb_krb5_socket_send(struct smb_krb5_socket *smb_krb5)
 195 {
 196         NTSTATUS status;
 197
 198         size_t len;
 199
 200         len = smb_krb5->request.length;
 201         status = socket_send(smb_krb5->sock, &smb_krb5->request, &len, 0);
 202
 203         if (!NT_STATUS_IS_OK(status)) return;
 204
 205         EVENT_FD_READABLE(smb_krb5->fde);
 206
 207         EVENT_FD_NOT_WRITEABLE(smb_krb5->fde);
 208         return;
 209 }
 210
 211
 212 /*
 213   handle fd events on a smb_krb5_socket
 214 */
 215 static void smb_krb5_socket_handler(struct event_context *ev, struct fd_event *fde,
 216                                  uint16_t flags, void *private)
 217 {
 218         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private, struct smb_krb5_socket);
 219         if (flags & EVENT_FD_WRITE) {
 220                 smb_krb5_socket_send(smb_krb5);
 221         }
 222         if (flags & EVENT_FD_READ) {
 223                 smb_krb5_socket_recv(smb_krb5);
 224         }
 225 }
 226
 227
 228 static krb5_error_code smb_krb5_send_and_recv_func(krb5_context context,
 229                                                    void *data,
 230                                                    krb5_krbhst_info *hi,
 231                                                    const krb5_data *send_buf,
 232                                                    krb5_data *recv_buf)
 233 {
 234         krb5_error_code ret;
 235         NTSTATUS status;
 236         struct socket_address *remote_addr;
 237         const char *name;
 238         struct addrinfo *ai, *a;
 239         struct smb_krb5_socket *smb_krb5;
 240
 241         struct event_context *ev = talloc_get_type(data, struct event_context);
 242
 243         DATA_BLOB send_blob = data_blob_const(send_buf->data, send_buf->length);
 244
 245         ret = krb5_krbhst_get_addrinfo(context, hi, &ai);
 246         if (ret) {
 247                 return ret;
 248         }
 249
 250         for (a = ai; a; a = ai->ai_next) {
 251                 smb_krb5 = talloc(NULL, struct smb_krb5_socket);
 252                 if (!smb_krb5) {
 253                         return ENOMEM;
 254                 }
 255                 smb_krb5->hi = hi;
 256
 257                 switch (a->ai_family) {
 258                 case PF_INET:
 259                         name = "ipv4";
 260                         break;
 261                 case PF_INET6:
 262                         name = "ipv6";
 263                         break;
 264                 default:
 265                         talloc_free(smb_krb5);
 266                         return EINVAL;
 267                 }
 268
 269                 status = NT_STATUS_INVALID_PARAMETER;
 270                 switch (hi->proto) {
 271                 case KRB5_KRBHST_UDP:
 272                         if (lp_parm_bool(-1, "krb5", "udp", True)) {
 273                                 status = socket_create(name, SOCKET_TYPE_DGRAM, &smb_krb5->sock, 0);
 274                                 break;
 275                         }
 276                 case KRB5_KRBHST_TCP:
 277                         if (lp_parm_bool(-1, "krb5", "tcp", True)) {
 278                                 status = socket_create(name, SOCKET_TYPE_STREAM, &smb_krb5->sock, 0);
 279                                 break;
 280                         }
 281                 case KRB5_KRBHST_HTTP:
 282                         talloc_free(smb_krb5);
 283                         return EINVAL;
 284                 }
 285                 if (!NT_STATUS_IS_OK(status)) {
 286                         talloc_free(smb_krb5);
 287                         continue;
 288                 }
 289
 290                 talloc_steal(smb_krb5, smb_krb5->sock);
 291
 292                 remote_addr = socket_address_from_sockaddr(smb_krb5, a->ai_addr, a->ai_addrlen);
 293                 if (!remote_addr) {
 294                         talloc_free(smb_krb5);
 295                         continue;
 296                 }
 297
 298                 status = socket_connect_ev(smb_krb5->sock, NULL, remote_addr, 0, ev);
 299                 if (!NT_STATUS_IS_OK(status)) {
 300                         talloc_free(smb_krb5);
 301                         continue;
 302                 }
 303                 talloc_free(remote_addr);
 304
 305                 smb_krb5->fde = event_add_fd(ev, smb_krb5,
 306                                              socket_get_fd(smb_krb5->sock), 0,
 307                                              smb_krb5_socket_handler, smb_krb5);
 308
 309                 event_add_timed(ev, smb_krb5,
 310                                 timeval_current_ofs(context->kdc_timeout, 0),
 311                                 smb_krb5_request_timeout, smb_krb5);
 312
 313                 EVENT_FD_WRITEABLE(smb_krb5->fde);
 314
 315                 switch (hi->proto) {
 316                 case KRB5_KRBHST_UDP:
 317                         smb_krb5->request = send_blob;
 318                         break;
 319                 case KRB5_KRBHST_TCP:
 320                         smb_krb5->request = data_blob_talloc(smb_krb5, NULL, send_blob.length + 4);
 321                         RSIVAL(smb_krb5->request.data, 0, send_blob.length);
 322                         memcpy(smb_krb5->request.data+4, send_blob.data, send_blob.length);
 323                         break;
 324                 case KRB5_KRBHST_HTTP:
 325                         talloc_free(smb_krb5);
 326                         return EINVAL;
 327                 }
 328                 smb_krb5->timeout = False;
 329                 smb_krb5->status = NT_STATUS_OK;
 330                 smb_krb5->reply = data_blob(NULL, 0);
 331                 smb_krb5->partial = data_blob(NULL, 0);
 332
 333                 while (!smb_krb5->timeout && (NT_STATUS_IS_OK(smb_krb5->status)) && !smb_krb5->reply.length) {
 334                         if (event_loop_once(ev) != 0) {
 335                                 talloc_free(smb_krb5);
 336                                 return EINVAL;
 337                         }
 338                 }
 339                 if (!NT_STATUS_IS_OK(smb_krb5->status)) {
 340                         DEBUG(2,("Error reading smb_krb5 reply packet: %s\n", nt_errstr(smb_krb5->status)));
 341                         talloc_free(smb_krb5);
 342                         continue;
 343                 }
 344
 345                 if (smb_krb5->timeout) {
 346                         talloc_free(smb_krb5);
 347                         continue;
 348                 }
 349
 350                 ret = krb5_data_copy(recv_buf, smb_krb5->reply.data, smb_krb5->reply.length);
 351                 if (ret) {
 352                         talloc_free(smb_krb5);
 353                         return ret;
 354                 }
 355                 talloc_free(smb_krb5);
 356
 357                 break;
 358         }
 359         if (a) {
 360                 return 0;
 361         }
 362         return KRB5_KDC_UNREACH;
 363 }
 364
 365 /* NO internal data, so nothing to free */
 366 static void smb_krb5_send_and_recv_close_func(krb5_context context, void *data)
 367 {
 368         return;
 369 }
 370
 371
 372 krb5_error_code smb_krb5_init_context(void *parent_ctx,
 373                                        struct smb_krb5_context **smb_krb5_context)
 374 {
 375         krb5_error_code ret;
 376         TALLOC_CTX *tmp_ctx;
 377         struct event_context *ev;
 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(*smb_krb5_context);
 386                 talloc_free(tmp_ctx);
 387                 return ENOMEM;
 388         }
 389
 390         ret = krb5_init_context(&(*smb_krb5_context)->krb5_context);
 391         if (ret) {
 392                 DEBUG(1,("krb5_init_context failed (%s)\n",
 393                          error_message(ret)));
 394                 return ret;
 395         }
 396
 397         talloc_set_destructor(*smb_krb5_context, smb_krb5_context_destroy_1);
 398
 399         if (lp_realm() && *lp_realm()) {
 400                 char *upper_realm = strupper_talloc(tmp_ctx, lp_realm());
 401                 if (!upper_realm) {
 402                         DEBUG(1,("gensec_krb5_start: could not uppercase realm: %s\n", lp_realm()));
 403                         talloc_free(tmp_ctx);
 404                         return ENOMEM;
 405                 }
 406                 ret = krb5_set_default_realm((*smb_krb5_context)->krb5_context, upper_realm);
 407                 if (ret) {
 408                         DEBUG(1,("krb5_set_default_realm 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
 415         /* TODO: Should we have a different name here? */
 416         ret = krb5_initlog((*smb_krb5_context)->krb5_context, "Samba", &(*smb_krb5_context)->logf);
 417
 418         if (ret) {
 419                 DEBUG(1,("krb5_initlog failed (%s)\n",
 420                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 421                 talloc_free(tmp_ctx);
 422                 return ret;
 423         }
 424
 425         talloc_set_destructor(*smb_krb5_context, smb_krb5_context_destroy_2);
 426
 427         ret = krb5_addlog_func((*smb_krb5_context)->krb5_context, (*smb_krb5_context)->logf, 0 /* min */, -1 /* max */,
 428                                smb_krb5_debug_wrapper, smb_krb5_debug_close, NULL);
 429         if (ret) {
 430                 DEBUG(1,("krb5_addlog_func failed (%s)\n",
 431                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 432                 talloc_free(tmp_ctx);
 433                 return ret;
 434         }
 435         krb5_set_warn_dest((*smb_krb5_context)->krb5_context, (*smb_krb5_context)->logf);
 436
 437         ev = event_context_find(*smb_krb5_context);
 438         /* Set use of our socket lib */
 439         ret = krb5_set_send_recv_func((*smb_krb5_context)->krb5_context,
 440                                       smb_krb5_send_and_recv_func,
 441                                       smb_krb5_send_and_recv_close_func, ev);
 442         if (ret) {
 443                 DEBUG(1,("krb5_set_send_recv_func failed (%s)\n",
 444                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
 445                 talloc_free(tmp_ctx);
 446                 return ret;
 447         }
 448
 449         (*smb_krb5_context)->krb5_context->mem_ctx = *smb_krb5_context;
 450
 451         talloc_steal(parent_ctx, *smb_krb5_context);
 452         talloc_free(tmp_ctx);
 453
 454         /* Set options in kerberos */
 455
 456         (*smb_krb5_context)->krb5_context->fdns = FALSE;
 457
 458         return 0;
 459 }
 460
 461  void smb_krb5_free_context(struct smb_krb5_context *smb_krb5_context)
 462 {
 463         talloc_free(smb_krb5_context);
 464 }