source4/auth/gensec/gensec_tstream.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    tstream based generic authentication interface
   5
   6    Copyright (c) 2010 Stefan Metzmacher
   7    Copyright (c) 2010 Andreas Schneider <asn@redhat.com>
   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/network.h"
  25 #include "auth/gensec/gensec.h"
  26 #include "auth/gensec/gensec_proto.h"
  27 #include "auth/gensec/gensec_tstream.h"
  28 #include "lib/tsocket/tsocket.h"
  29 #include "lib/tsocket/tsocket_internal.h"
  30 #include "auth/gensec/gensec_toplevel_proto.h"
  31
  32 static const struct tstream_context_ops tstream_gensec_ops;
  33
  34 struct tstream_gensec {
  35         struct tstream_context *plain_stream;
  36
  37         struct gensec_security *gensec_security;
  38
  39         int error;
  40
  41         struct {
  42                 size_t max_unwrapped_size;
  43                 size_t max_wrapped_size;
  44         } write;
  45
  46         struct {
  47                 off_t ofs;
  48                 size_t left;
  49                 DATA_BLOB unwrapped;
  50         } read;
  51 };
  52
  53 _PUBLIC_ NTSTATUS _gensec_create_tstream(TALLOC_CTX *mem_ctx,
  54                                          struct gensec_security *gensec_security,
  55                                          struct tstream_context *plain_stream,
  56                                          struct tstream_context **_gensec_stream,
  57                                          const char *location)
  58 {
  59         struct tstream_context *gensec_stream;
  60         struct tstream_gensec *tgss;
  61
  62         gensec_stream = tstream_context_create(mem_ctx,
  63                                                &tstream_gensec_ops,
  64                                                &tgss,
  65                                                struct tstream_gensec,
  66                                                location);
  67         if (gensec_stream == NULL) {
  68                 return NT_STATUS_NO_MEMORY;
  69         }
  70
  71         tgss->plain_stream = plain_stream;
  72         tgss->gensec_security = gensec_security;
  73         tgss->error = 0;
  74
  75         if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN) &&
  76             !gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
  77                 talloc_free(gensec_stream);
  78                 return NT_STATUS_INVALID_PARAMETER;
  79         }
  80
  81         tgss->write.max_unwrapped_size = gensec_max_input_size(gensec_security);
  82         tgss->write.max_wrapped_size = gensec_max_wrapped_size(gensec_security);
  83
  84         ZERO_STRUCT(tgss->read);
  85
  86         *_gensec_stream = gensec_stream;
  87         return NT_STATUS_OK;
  88 }
  89
  90 static ssize_t tstream_gensec_pending_bytes(struct tstream_context *stream)
  91 {
  92         struct tstream_gensec *tgss =
  93                 tstream_context_data(stream,
  94                 struct tstream_gensec);
  95
  96         if (tgss->error != 0) {
  97                 errno = tgss->error;
  98                 return -1;
  99         }
 100
 101         return tgss->read.left;
 102 }
 103
 104 struct tstream_gensec_readv_state {
 105         struct tevent_context *ev;
 106         struct tstream_context *stream;
 107
 108         struct iovec *vector;
 109         int count;
 110
 111         struct {
 112                 bool asked_for_hdr;
 113                 uint8_t hdr[4];
 114                 bool asked_for_blob;
 115                 DATA_BLOB blob;
 116         } wrapped;
 117
 118         int ret;
 119 };
 120
 121 static void tstream_gensec_readv_wrapped_next(struct tevent_req *req);
 122
 123 static struct tevent_req *tstream_gensec_readv_send(TALLOC_CTX *mem_ctx,
 124                                                     struct tevent_context *ev,
 125                                                     struct tstream_context *stream,
 126                                                     struct iovec *vector,
 127                                                     size_t count)
 128 {
 129         struct tstream_gensec *tgss =
 130                 tstream_context_data(stream,
 131                 struct tstream_gensec);
 132         struct tevent_req *req;
 133         struct tstream_gensec_readv_state *state;
 134
 135         req = tevent_req_create(mem_ctx, &state,
 136                                 struct tstream_gensec_readv_state);
 137         if (!req) {
 138                 return NULL;
 139         }
 140
 141         if (tgss->error != 0) {
 142                 tevent_req_error(req, tgss->error);
 143                 return tevent_req_post(req, ev);
 144         }
 145
 146         state->ev = ev;
 147         state->stream = stream;
 148         state->ret = 0;
 149
 150         /*
 151          * we make a copy of the vector so we can change the structure
 152          */
 153         state->vector = talloc_array(state, struct iovec, count);
 154         if (tevent_req_nomem(state->vector, req)) {
 155                 return tevent_req_post(req, ev);
 156         }
 157         memcpy(state->vector, vector, sizeof(struct iovec) * count);
 158         state->count = count;
 159
 160         tstream_gensec_readv_wrapped_next(req);
 161         if (!tevent_req_is_in_progress(req)) {
 162                 return tevent_req_post(req, ev);
 163         }
 164
 165         return req;
 166 }
 167
 168 static int tstream_gensec_readv_next_vector(struct tstream_context *unix_stream,
 169                                             void *private_data,
 170                                             TALLOC_CTX *mem_ctx,
 171                                             struct iovec **_vector,
 172                                             size_t *_count);
 173 static void tstream_gensec_readv_wrapped_done(struct tevent_req *subreq);
 174
 175 static void tstream_gensec_readv_wrapped_next(struct tevent_req *req)
 176 {
 177         struct tstream_gensec_readv_state *state =
 178                 tevent_req_data(req,
 179                 struct tstream_gensec_readv_state);
 180         struct tstream_gensec *tgss =
 181                 tstream_context_data(state->stream,
 182                 struct tstream_gensec);
 183         struct tevent_req *subreq;
 184
 185         /*
 186          * copy the pending buffer first
 187          */
 188         while (tgss->read.left > 0 && state->count > 0) {
 189                 uint8_t *base = (uint8_t *)state->vector[0].iov_base;
 190                 size_t len = MIN(tgss->read.left, state->vector[0].iov_len);
 191
 192                 memcpy(base, tgss->read.unwrapped.data + tgss->read.ofs, len);
 193
 194                 base += len;
 195                 state->vector[0].iov_base = (char *) base;
 196                 state->vector[0].iov_len -= len;
 197
 198                 tgss->read.ofs += len;
 199                 tgss->read.left -= len;
 200
 201                 if (state->vector[0].iov_len == 0) {
 202                         state->vector += 1;
 203                         state->count -= 1;
 204                 }
 205
 206                 state->ret += len;
 207         }
 208
 209         if (state->count == 0) {
 210                 tevent_req_done(req);
 211                 return;
 212         }
 213
 214         data_blob_free(&tgss->read.unwrapped);
 215         ZERO_STRUCT(state->wrapped);
 216
 217         subreq = tstream_readv_pdu_send(state, state->ev,
 218                                         tgss->plain_stream,
 219                                         tstream_gensec_readv_next_vector,
 220                                         state);
 221         if (tevent_req_nomem(subreq, req)) {
 222                 return;
 223         }
 224         tevent_req_set_callback(subreq, tstream_gensec_readv_wrapped_done, req);
 225 }
 226
 227 static int tstream_gensec_readv_next_vector(struct tstream_context *unix_stream,
 228                                             void *private_data,
 229                                             TALLOC_CTX *mem_ctx,
 230                                             struct iovec **_vector,
 231                                             size_t *_count)
 232 {
 233         struct tstream_gensec_readv_state *state =
 234                 talloc_get_type_abort(private_data,
 235                 struct tstream_gensec_readv_state);
 236         struct iovec *vector;
 237         size_t count = 1;
 238
 239         /* we need to get a message header */
 240         vector = talloc_array(mem_ctx, struct iovec, count);
 241         if (!vector) {
 242                 return -1;
 243         }
 244
 245         if (!state->wrapped.asked_for_hdr) {
 246                 state->wrapped.asked_for_hdr = true;
 247                 vector[0].iov_base = (char *)state->wrapped.hdr;
 248                 vector[0].iov_len = sizeof(state->wrapped.hdr);
 249         } else if (!state->wrapped.asked_for_blob) {
 250                 uint32_t msg_len;
 251
 252                 state->wrapped.asked_for_blob = true;
 253
 254                 msg_len = RIVAL(state->wrapped.hdr, 0);
 255
 256                 if (msg_len > 0x00FFFFFF) {
 257                         errno = EMSGSIZE;
 258                         return -1;
 259                 }
 260
 261                 if (msg_len == 0) {
 262                         errno = EMSGSIZE;
 263                         return -1;
 264                 }
 265
 266                 state->wrapped.blob = data_blob_talloc(state, NULL, msg_len);
 267                 if (state->wrapped.blob.data == NULL) {
 268                         return -1;
 269                 }
 270
 271                 vector[0].iov_base = (char *)state->wrapped.blob.data;
 272                 vector[0].iov_len = state->wrapped.blob.length;
 273         } else {
 274                 *_vector = NULL;
 275                 *_count = 0;
 276                 return 0;
 277         }
 278
 279         *_vector = vector;
 280         *_count = count;
 281         return 0;
 282 }
 283
 284 static void tstream_gensec_readv_wrapped_done(struct tevent_req *subreq)
 285 {
 286         struct tevent_req *req =
 287                 tevent_req_callback_data(subreq,
 288                 struct tevent_req);
 289         struct tstream_gensec_readv_state *state =
 290                 tevent_req_data(req,
 291                 struct tstream_gensec_readv_state);
 292         struct tstream_gensec *tgss =
 293                 tstream_context_data(state->stream,
 294                 struct tstream_gensec);
 295         int ret;
 296         int sys_errno;
 297         NTSTATUS status;
 298
 299         ret = tstream_readv_pdu_recv(subreq, &sys_errno);
 300         TALLOC_FREE(subreq);
 301         if (ret == -1) {
 302                 tgss->error = sys_errno;
 303                 tevent_req_error(req, sys_errno);
 304                 return;
 305         }
 306
 307         status = gensec_unwrap(tgss->gensec_security,
 308                                state,
 309                                &state->wrapped.blob,
 310                                &tgss->read.unwrapped);
 311         if (!NT_STATUS_IS_OK(status)) {
 312                 tgss->error = EIO;
 313                 tevent_req_error(req, tgss->error);
 314                 return;
 315         }
 316
 317         data_blob_free(&state->wrapped.blob);
 318
 319         talloc_steal(tgss, tgss->read.unwrapped.data);
 320         tgss->read.left = tgss->read.unwrapped.length;
 321         tgss->read.ofs = 0;
 322
 323         tstream_gensec_readv_wrapped_next(req);
 324 }
 325
 326 static int tstream_gensec_readv_recv(struct tevent_req *req, int *perrno)
 327 {
 328         struct tstream_gensec_readv_state *state =
 329                 tevent_req_data(req,
 330                 struct tstream_gensec_readv_state);
 331         int ret;
 332
 333         ret = tsocket_simple_int_recv(req, perrno);
 334         if (ret == 0) {
 335                 ret = state->ret;
 336         }
 337
 338         tevent_req_received(req);
 339         return ret;
 340 }
 341
 342 struct tstream_gensec_writev_state {
 343         struct tevent_context *ev;
 344         struct tstream_context *stream;
 345
 346         struct iovec *vector;
 347         int count;
 348
 349         struct {
 350                 off_t ofs;
 351                 size_t left;
 352                 DATA_BLOB blob;
 353         } unwrapped;
 354
 355         struct {
 356                 uint8_t hdr[4];
 357                 DATA_BLOB blob;
 358                 struct iovec iov[2];
 359         } wrapped;
 360
 361         int ret;
 362 };
 363
 364 static void tstream_gensec_writev_wrapped_next(struct tevent_req *req);
 365
 366 static struct tevent_req *tstream_gensec_writev_send(TALLOC_CTX *mem_ctx,
 367                                         struct tevent_context *ev,
 368                                         struct tstream_context *stream,
 369                                         const struct iovec *vector,
 370                                         size_t count)
 371 {
 372         struct tstream_gensec *tgss =
 373                 tstream_context_data(stream,
 374                 struct tstream_gensec);
 375         struct tevent_req *req;
 376         struct tstream_gensec_writev_state *state;
 377         int i;
 378         int total;
 379         int chunk;
 380
 381         req = tevent_req_create(mem_ctx, &state,
 382                                 struct tstream_gensec_writev_state);
 383         if (req == NULL) {
 384                 return NULL;
 385         }
 386
 387         if (tgss->error != 0) {
 388                 tevent_req_error(req, tgss->error);
 389                 return tevent_req_post(req, ev);
 390         }
 391
 392         state->ev = ev;
 393         state->stream = stream;
 394         state->ret = 0;
 395
 396         /*
 397          * we make a copy of the vector so we can change the structure
 398          */
 399         state->vector = talloc_array(state, struct iovec, count);
 400         if (tevent_req_nomem(state->vector, req)) {
 401                 return tevent_req_post(req, ev);
 402         }
 403         memcpy(state->vector, vector, sizeof(struct iovec) * count);
 404         state->count = count;
 405
 406         total = 0;
 407         for (i = 0; i < count; i++) {
 408                 /*
 409                  * the generic tstream code makes sure that
 410                  * this never wraps.
 411                  */
 412                 total += vector[i].iov_len;
 413         }
 414
 415         /*
 416          * We may need to send data in chunks.
 417          */
 418         chunk = MIN(total, tgss->write.max_unwrapped_size);
 419
 420         state->unwrapped.blob = data_blob_talloc(state, NULL, chunk);
 421         if (tevent_req_nomem(state->unwrapped.blob.data, req)) {
 422                 return tevent_req_post(req, ev);
 423         }
 424
 425         tstream_gensec_writev_wrapped_next(req);
 426         if (!tevent_req_is_in_progress(req)) {
 427                 return tevent_req_post(req, ev);
 428         }
 429
 430         return req;
 431 }
 432
 433 static void tstream_gensec_writev_wrapped_done(struct tevent_req *subreq);
 434
 435 static void tstream_gensec_writev_wrapped_next(struct tevent_req *req)
 436 {
 437         struct tstream_gensec_writev_state *state =
 438                 tevent_req_data(req,
 439                 struct tstream_gensec_writev_state);
 440         struct tstream_gensec *tgss =
 441                 tstream_context_data(state->stream,
 442                 struct tstream_gensec);
 443         struct tevent_req *subreq;
 444         NTSTATUS status;
 445
 446         data_blob_free(&state->wrapped.blob);
 447
 448         state->unwrapped.left = state->unwrapped.blob.length;
 449         state->unwrapped.ofs = 0;
 450
 451         /*
 452          * first fill our buffer
 453          */
 454         while (state->unwrapped.left > 0 && state->count > 0) {
 455                 uint8_t *base = (uint8_t *)state->vector[0].iov_base;
 456                 size_t len = MIN(state->unwrapped.left, state->vector[0].iov_len);
 457
 458                 memcpy(state->unwrapped.blob.data + state->unwrapped.ofs, base, len);
 459
 460                 base += len;
 461                 state->vector[0].iov_base = (char *) base;
 462                 state->vector[0].iov_len -= len;
 463
 464                 state->unwrapped.ofs += len;
 465                 state->unwrapped.left -= len;
 466
 467                 if (state->vector[0].iov_len == 0) {
 468                         state->vector += 1;
 469                         state->count -= 1;
 470                 }
 471
 472                 state->ret += len;
 473         }
 474
 475         if (state->unwrapped.ofs == 0) {
 476                 tevent_req_done(req);
 477                 return;
 478         }
 479
 480         state->unwrapped.blob.length = state->unwrapped.ofs;
 481
 482         status = gensec_wrap(tgss->gensec_security,
 483                              state,
 484                              &state->unwrapped.blob,
 485                              &state->wrapped.blob);
 486         if (!NT_STATUS_IS_OK(status)) {
 487                 tgss->error = EIO;
 488                 tevent_req_error(req, tgss->error);
 489                 return;
 490         }
 491
 492         RSIVAL(state->wrapped.hdr, 0, state->wrapped.blob.length);
 493
 494         state->wrapped.iov[0].iov_base = (void *)state->wrapped.hdr;
 495         state->wrapped.iov[0].iov_len = sizeof(state->wrapped.hdr);
 496         state->wrapped.iov[1].iov_base = (void *)state->wrapped.blob.data;
 497         state->wrapped.iov[1].iov_len = state->wrapped.blob.length;
 498
 499         subreq = tstream_writev_send(state, state->ev,
 500                                       tgss->plain_stream,
 501                                       state->wrapped.iov, 2);
 502         if (tevent_req_nomem(subreq, req)) {
 503                 return;
 504         }
 505         tevent_req_set_callback(subreq,
 506                                 tstream_gensec_writev_wrapped_done,
 507                                 req);
 508 }
 509
 510 static void tstream_gensec_writev_wrapped_done(struct tevent_req *subreq)
 511 {
 512         struct tevent_req *req =
 513                 tevent_req_callback_data(subreq,
 514                 struct tevent_req);
 515         struct tstream_gensec_writev_state *state =
 516                 tevent_req_data(req,
 517                 struct tstream_gensec_writev_state);
 518         struct tstream_gensec *tgss =
 519                 tstream_context_data(state->stream,
 520                 struct tstream_gensec);
 521         int sys_errno;
 522         int ret;
 523
 524         ret = tstream_writev_recv(subreq, &sys_errno);
 525         TALLOC_FREE(subreq);
 526         if (ret == -1) {
 527                 tgss->error = sys_errno;
 528                 tevent_req_error(req, sys_errno);
 529                 return;
 530         }
 531
 532         tstream_gensec_writev_wrapped_next(req);
 533 }
 534
 535 static int tstream_gensec_writev_recv(struct tevent_req *req,
 536                                    int *perrno)
 537 {
 538         struct tstream_gensec_writev_state *state =
 539                 tevent_req_data(req,
 540                 struct tstream_gensec_writev_state);
 541         int ret;
 542
 543         ret = tsocket_simple_int_recv(req, perrno);
 544         if (ret == 0) {
 545                 ret = state->ret;
 546         }
 547
 548         tevent_req_received(req);
 549         return ret;
 550 }
 551
 552 struct tstream_gensec_disconnect_state {
 553         uint8_t _dummy;
 554 };
 555
 556 static struct tevent_req *tstream_gensec_disconnect_send(TALLOC_CTX *mem_ctx,
 557                                                          struct tevent_context *ev,
 558                                                          struct tstream_context *stream)
 559 {
 560         struct tstream_gensec *tgss =
 561                 tstream_context_data(stream,
 562                 struct tstream_gensec);
 563         struct tevent_req *req;
 564         struct tstream_gensec_disconnect_state *state;
 565
 566         req = tevent_req_create(mem_ctx, &state,
 567                                 struct tstream_gensec_disconnect_state);
 568         if (req == NULL) {
 569                 return NULL;
 570         }
 571
 572         if (tgss->error != 0) {
 573                 tevent_req_error(req, tgss->error);
 574                 return tevent_req_post(req, ev);
 575         }
 576
 577         /*
 578          * The caller is responsible to do the real disconnect
 579          * on the plain stream!
 580          */
 581         tgss->plain_stream = NULL;
 582         tgss->error = ENOTCONN;
 583
 584         tevent_req_done(req);
 585         return tevent_req_post(req, ev);
 586 }
 587
 588 static int tstream_gensec_disconnect_recv(struct tevent_req *req,
 589                                        int *perrno)
 590 {
 591         int ret;
 592
 593         ret = tsocket_simple_int_recv(req, perrno);
 594
 595         tevent_req_received(req);
 596         return ret;
 597 }
 598
 599 static const struct tstream_context_ops tstream_gensec_ops = {
 600         .name                   = "gensec",
 601
 602         .pending_bytes          = tstream_gensec_pending_bytes,
 603
 604         .readv_send             = tstream_gensec_readv_send,
 605         .readv_recv             = tstream_gensec_readv_recv,
 606
 607         .writev_send            = tstream_gensec_writev_send,
 608         .writev_recv            = tstream_gensec_writev_recv,
 609
 610         .disconnect_send        = tstream_gensec_disconnect_send,
 611         .disconnect_recv        = tstream_gensec_disconnect_recv,
 612 };