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                 state->wrapped.asked_for_blob = true;
 251                 uint32_t msg_len;
 252
 253                 msg_len = RIVAL(state->wrapped.hdr, 0);
 254
 255                 if (msg_len > 0x00FFFFFF) {
 256                         errno = EMSGSIZE;
 257                         return -1;
 258                 }
 259
 260                 if (msg_len == 0) {
 261                         errno = EMSGSIZE;
 262                         return -1;
 263                 }
 264
 265                 state->wrapped.blob = data_blob_talloc(state, NULL, msg_len);
 266                 if (state->wrapped.blob.data == NULL) {
 267                         return -1;
 268                 }
 269
 270                 vector[0].iov_base = (char *)state->wrapped.blob.data;
 271                 vector[0].iov_len = state->wrapped.blob.length;
 272         } else {
 273                 *_vector = NULL;
 274                 *_count = 0;
 275                 return 0;
 276         }
 277
 278         *_vector = vector;
 279         *_count = count;
 280         return 0;
 281 }
 282
 283 static void tstream_gensec_readv_wrapped_done(struct tevent_req *subreq)
 284 {
 285         struct tevent_req *req =
 286                 tevent_req_callback_data(subreq,
 287                 struct tevent_req);
 288         struct tstream_gensec_readv_state *state =
 289                 tevent_req_data(req,
 290                 struct tstream_gensec_readv_state);
 291         struct tstream_gensec *tgss =
 292                 tstream_context_data(state->stream,
 293                 struct tstream_gensec);
 294         int ret;
 295         int sys_errno;
 296         NTSTATUS status;
 297
 298         ret = tstream_readv_pdu_recv(subreq, &sys_errno);
 299         TALLOC_FREE(subreq);
 300         if (ret == -1) {
 301                 tgss->error = sys_errno;
 302                 tevent_req_error(req, sys_errno);
 303                 return;
 304         }
 305
 306         status = gensec_unwrap(tgss->gensec_security,
 307                                state,
 308                                &state->wrapped.blob,
 309                                &tgss->read.unwrapped);
 310         if (!NT_STATUS_IS_OK(status)) {
 311                 tgss->error = EIO;
 312                 tevent_req_error(req, tgss->error);
 313                 return;
 314         }
 315
 316         data_blob_free(&state->wrapped.blob);
 317
 318         talloc_steal(tgss, tgss->read.unwrapped.data);
 319         tgss->read.left = tgss->read.unwrapped.length;
 320         tgss->read.ofs = 0;
 321
 322         tstream_gensec_readv_wrapped_next(req);
 323 }
 324
 325 static int tstream_gensec_readv_recv(struct tevent_req *req, int *perrno)
 326 {
 327         struct tstream_gensec_readv_state *state =
 328                 tevent_req_data(req,
 329                 struct tstream_gensec_readv_state);
 330         int ret;
 331
 332         ret = tsocket_simple_int_recv(req, perrno);
 333         if (ret == 0) {
 334                 ret = state->ret;
 335         }
 336
 337         tevent_req_received(req);
 338         return ret;
 339 }
 340
 341 struct tstream_gensec_writev_state {
 342         struct tevent_context *ev;
 343         struct tstream_context *stream;
 344
 345         struct iovec *vector;
 346         int count;
 347
 348         struct {
 349                 off_t ofs;
 350                 size_t left;
 351                 DATA_BLOB blob;
 352         } unwrapped;
 353
 354         struct {
 355                 uint8_t hdr[4];
 356                 DATA_BLOB blob;
 357                 struct iovec iov[2];
 358         } wrapped;
 359
 360         int ret;
 361 };
 362
 363 static void tstream_gensec_writev_wrapped_next(struct tevent_req *req);
 364
 365 static struct tevent_req *tstream_gensec_writev_send(TALLOC_CTX *mem_ctx,
 366                                         struct tevent_context *ev,
 367                                         struct tstream_context *stream,
 368                                         const struct iovec *vector,
 369                                         size_t count)
 370 {
 371         struct tstream_gensec *tgss =
 372                 tstream_context_data(stream,
 373                 struct tstream_gensec);
 374         struct tevent_req *req;
 375         struct tstream_gensec_writev_state *state;
 376         int i;
 377         int total;
 378         int chunk;
 379
 380         req = tevent_req_create(mem_ctx, &state,
 381                                 struct tstream_gensec_writev_state);
 382         if (req == NULL) {
 383                 return NULL;
 384         }
 385
 386         if (tgss->error != 0) {
 387                 tevent_req_error(req, tgss->error);
 388                 return tevent_req_post(req, ev);
 389         }
 390
 391         state->ev = ev;
 392         state->stream = stream;
 393         state->ret = 0;
 394
 395         /*
 396          * we make a copy of the vector so we can change the structure
 397          */
 398         state->vector = talloc_array(state, struct iovec, count);
 399         if (tevent_req_nomem(state->vector, req)) {
 400                 return tevent_req_post(req, ev);
 401         }
 402         memcpy(state->vector, vector, sizeof(struct iovec) * count);
 403         state->count = count;
 404
 405         total = 0;
 406         for (i = 0; i < count; i++) {
 407                 /*
 408                  * the generic tstream code makes sure that
 409                  * this never wraps.
 410                  */
 411                 total += vector[i].iov_len;
 412         }
 413
 414         /*
 415          * We may need to send data in chunks.
 416          */
 417         chunk = MIN(total, tgss->write.max_unwrapped_size);
 418
 419         state->unwrapped.blob = data_blob_talloc(state, NULL, chunk);
 420         if (tevent_req_nomem(state->unwrapped.blob.data, req)) {
 421                 return tevent_req_post(req, ev);
 422         }
 423
 424         tstream_gensec_writev_wrapped_next(req);
 425         if (!tevent_req_is_in_progress(req)) {
 426                 return tevent_req_post(req, ev);
 427         }
 428
 429         return req;
 430 }
 431
 432 static void tstream_gensec_writev_wrapped_done(struct tevent_req *subreq);
 433
 434 static void tstream_gensec_writev_wrapped_next(struct tevent_req *req)
 435 {
 436         struct tstream_gensec_writev_state *state =
 437                 tevent_req_data(req,
 438                 struct tstream_gensec_writev_state);
 439         struct tstream_gensec *tgss =
 440                 tstream_context_data(state->stream,
 441                 struct tstream_gensec);
 442         struct tevent_req *subreq;
 443         NTSTATUS status;
 444
 445         data_blob_free(&state->wrapped.blob);
 446
 447         state->unwrapped.left = state->unwrapped.blob.length;
 448         state->unwrapped.ofs = 0;
 449
 450         /*
 451          * first fill our buffer
 452          */
 453         while (state->unwrapped.left > 0 && state->count > 0) {
 454                 uint8_t *base = (uint8_t *)state->vector[0].iov_base;
 455                 size_t len = MIN(state->unwrapped.left, state->vector[0].iov_len);
 456
 457                 memcpy(state->unwrapped.blob.data + state->unwrapped.ofs, base, len);
 458
 459                 base += len;
 460                 state->vector[0].iov_base = (char *) base;
 461                 state->vector[0].iov_len -= len;
 462
 463                 state->unwrapped.ofs += len;
 464                 state->unwrapped.left -= len;
 465
 466                 if (state->vector[0].iov_len == 0) {
 467                         state->vector += 1;
 468                         state->count -= 1;
 469                 }
 470
 471                 state->ret += len;
 472         }
 473
 474         if (state->unwrapped.ofs == 0) {
 475                 tevent_req_done(req);
 476                 return;
 477         }
 478
 479         state->unwrapped.blob.length = state->unwrapped.ofs;
 480
 481         status = gensec_wrap(tgss->gensec_security,
 482                              state,
 483                              &state->unwrapped.blob,
 484                              &state->wrapped.blob);
 485         if (!NT_STATUS_IS_OK(status)) {
 486                 tgss->error = EIO;
 487                 tevent_req_error(req, tgss->error);
 488                 return;
 489         }
 490
 491         RSIVAL(state->wrapped.hdr, 0, state->wrapped.blob.length);
 492
 493         state->wrapped.iov[0].iov_base = (void *)state->wrapped.hdr;
 494         state->wrapped.iov[0].iov_len = sizeof(state->wrapped.hdr);
 495         state->wrapped.iov[1].iov_base = (void *)state->wrapped.blob.data;
 496         state->wrapped.iov[1].iov_len = state->wrapped.blob.length;
 497
 498         subreq = tstream_writev_send(state, state->ev,
 499                                       tgss->plain_stream,
 500                                       state->wrapped.iov, 2);
 501         if (tevent_req_nomem(subreq, req)) {
 502                 return;
 503         }
 504         tevent_req_set_callback(subreq,
 505                                 tstream_gensec_writev_wrapped_done,
 506                                 req);
 507 }
 508
 509 static void tstream_gensec_writev_wrapped_done(struct tevent_req *subreq)
 510 {
 511         struct tevent_req *req =
 512                 tevent_req_callback_data(subreq,
 513                 struct tevent_req);
 514         struct tstream_gensec_writev_state *state =
 515                 tevent_req_data(req,
 516                 struct tstream_gensec_writev_state);
 517         struct tstream_gensec *tgss =
 518                 tstream_context_data(state->stream,
 519                 struct tstream_gensec);
 520         int sys_errno;
 521         int ret;
 522
 523         ret = tstream_writev_recv(subreq, &sys_errno);
 524         TALLOC_FREE(subreq);
 525         if (ret == -1) {
 526                 tgss->error = sys_errno;
 527                 tevent_req_error(req, sys_errno);
 528                 return;
 529         }
 530
 531         tstream_gensec_writev_wrapped_next(req);
 532 }
 533
 534 static int tstream_gensec_writev_recv(struct tevent_req *req,
 535                                    int *perrno)
 536 {
 537         struct tstream_gensec_writev_state *state =
 538                 tevent_req_data(req,
 539                 struct tstream_gensec_writev_state);
 540         int ret;
 541
 542         ret = tsocket_simple_int_recv(req, perrno);
 543         if (ret == 0) {
 544                 ret = state->ret;
 545         }
 546
 547         tevent_req_received(req);
 548         return ret;
 549 }
 550
 551 struct tstream_gensec_disconnect_state {
 552         uint8_t _dummy;
 553 };
 554
 555 static struct tevent_req *tstream_gensec_disconnect_send(TALLOC_CTX *mem_ctx,
 556                                                          struct tevent_context *ev,
 557                                                          struct tstream_context *stream)
 558 {
 559         struct tstream_gensec *tgss =
 560                 tstream_context_data(stream,
 561                 struct tstream_gensec);
 562         struct tevent_req *req;
 563         struct tstream_gensec_disconnect_state *state;
 564
 565         req = tevent_req_create(mem_ctx, &state,
 566                                 struct tstream_gensec_disconnect_state);
 567         if (req == NULL) {
 568                 return NULL;
 569         }
 570
 571         if (tgss->error != 0) {
 572                 tevent_req_error(req, tgss->error);
 573                 return tevent_req_post(req, ev);
 574         }
 575
 576         /*
 577          * The caller is responsible to do the real disconnect
 578          * on the plain stream!
 579          */
 580         tgss->plain_stream = NULL;
 581         tgss->error = ENOTCONN;
 582
 583         tevent_req_done(req);
 584         return tevent_req_post(req, ev);
 585 }
 586
 587 static int tstream_gensec_disconnect_recv(struct tevent_req *req,
 588                                        int *perrno)
 589 {
 590         int ret;
 591
 592         ret = tsocket_simple_int_recv(req, perrno);
 593
 594         tevent_req_received(req);
 595         return ret;
 596 }
 597
 598 static const struct tstream_context_ops tstream_gensec_ops = {
 599         .name                   = "gensec",
 600
 601         .pending_bytes          = tstream_gensec_pending_bytes,
 602
 603         .readv_send             = tstream_gensec_readv_send,
 604         .readv_recv             = tstream_gensec_readv_recv,
 605
 606         .writev_send            = tstream_gensec_writev_send,
 607         .writev_recv            = tstream_gensec_writev_recv,
 608
 609         .disconnect_send        = tstream_gensec_disconnect_send,
 610         .disconnect_recv        = tstream_gensec_disconnect_recv,
 611 };