auth/gensec/spnego.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    RFC2478 Compliant SPNEGO implementation
   5
   6    Copyright (C) Jim McDonough <jmcd@us.ibm.com>      2003
   7    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
   8    Copyright (C) Stefan Metzmacher <metze@samba.org>  2004-2008
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  23 */
  24
  25 #include "includes.h"
  26 #include "../libcli/auth/spnego.h"
  27 #include "librpc/gen_ndr/ndr_dcerpc.h"
  28 #include "auth/credentials/credentials.h"
  29 #include "auth/gensec/gensec.h"
  30 #include "param/param.h"
  31 #include "lib/util/asn1.h"
  32
  33 #undef strcasecmp
  34
  35 _PUBLIC_ NTSTATUS gensec_spnego_init(void);
  36
  37 enum spnego_state_position {
  38         SPNEGO_SERVER_START,
  39         SPNEGO_CLIENT_START,
  40         SPNEGO_SERVER_TARG,
  41         SPNEGO_CLIENT_TARG,
  42         SPNEGO_FALLBACK,
  43         SPNEGO_DONE
  44 };
  45
  46 struct spnego_state {
  47         enum spnego_message_type expected_packet;
  48         enum spnego_state_position state_position;
  49         struct gensec_security *sub_sec_security;
  50         bool no_response_expected;
  51
  52         const char *neg_oid;
  53
  54         DATA_BLOB mech_types;
  55
  56         /*
  57          * The following is used to implement
  58          * the update token fragmentation
  59          */
  60         size_t in_needed;
  61         DATA_BLOB in_frag;
  62         size_t out_max_length;
  63         DATA_BLOB out_frag;
  64         NTSTATUS out_status;
  65 };
  66
  67
  68 static NTSTATUS gensec_spnego_client_start(struct gensec_security *gensec_security)
  69 {
  70         struct spnego_state *spnego_state;
  71
  72         spnego_state = talloc_zero(gensec_security, struct spnego_state);
  73         if (!spnego_state) {
  74                 return NT_STATUS_NO_MEMORY;
  75         }
  76
  77         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_INIT;
  78         spnego_state->state_position = SPNEGO_CLIENT_START;
  79         spnego_state->sub_sec_security = NULL;
  80         spnego_state->no_response_expected = false;
  81         spnego_state->mech_types = data_blob(NULL, 0);
  82         spnego_state->out_max_length = gensec_max_update_size(gensec_security);
  83         spnego_state->out_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
  84
  85         gensec_security->private_data = spnego_state;
  86         return NT_STATUS_OK;
  87 }
  88
  89 static NTSTATUS gensec_spnego_server_start(struct gensec_security *gensec_security)
  90 {
  91         struct spnego_state *spnego_state;
  92
  93         spnego_state = talloc_zero(gensec_security, struct spnego_state);
  94         if (!spnego_state) {
  95                 return NT_STATUS_NO_MEMORY;
  96         }
  97
  98         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_INIT;
  99         spnego_state->state_position = SPNEGO_SERVER_START;
 100         spnego_state->sub_sec_security = NULL;
 101         spnego_state->no_response_expected = false;
 102         spnego_state->mech_types = data_blob(NULL, 0);
 103         spnego_state->out_max_length = gensec_max_update_size(gensec_security);
 104         spnego_state->out_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 105
 106         gensec_security->private_data = spnego_state;
 107         return NT_STATUS_OK;
 108 }
 109
 110 /*
 111   wrappers for the spnego_*() functions
 112 */
 113 static NTSTATUS gensec_spnego_unseal_packet(struct gensec_security *gensec_security,
 114                                             uint8_t *data, size_t length,
 115                                             const uint8_t *whole_pdu, size_t pdu_length,
 116                                             const DATA_BLOB *sig)
 117 {
 118         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 119
 120         if (spnego_state->state_position != SPNEGO_DONE
 121             && spnego_state->state_position != SPNEGO_FALLBACK) {
 122                 return NT_STATUS_INVALID_PARAMETER;
 123         }
 124
 125         return gensec_unseal_packet(spnego_state->sub_sec_security,
 126                                     data, length,
 127                                     whole_pdu, pdu_length,
 128                                     sig);
 129 }
 130
 131 static NTSTATUS gensec_spnego_check_packet(struct gensec_security *gensec_security,
 132                                            const uint8_t *data, size_t length,
 133                                            const uint8_t *whole_pdu, size_t pdu_length,
 134                                            const DATA_BLOB *sig)
 135 {
 136         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 137
 138         if (spnego_state->state_position != SPNEGO_DONE
 139             && spnego_state->state_position != SPNEGO_FALLBACK) {
 140                 return NT_STATUS_INVALID_PARAMETER;
 141         }
 142
 143         return gensec_check_packet(spnego_state->sub_sec_security,
 144                                    data, length,
 145                                    whole_pdu, pdu_length,
 146                                    sig);
 147 }
 148
 149 static NTSTATUS gensec_spnego_seal_packet(struct gensec_security *gensec_security,
 150                                           TALLOC_CTX *mem_ctx,
 151                                           uint8_t *data, size_t length,
 152                                           const uint8_t *whole_pdu, size_t pdu_length,
 153                                           DATA_BLOB *sig)
 154 {
 155         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 156
 157         if (spnego_state->state_position != SPNEGO_DONE
 158             && spnego_state->state_position != SPNEGO_FALLBACK) {
 159                 return NT_STATUS_INVALID_PARAMETER;
 160         }
 161
 162         return gensec_seal_packet(spnego_state->sub_sec_security,
 163                                   mem_ctx,
 164                                   data, length,
 165                                   whole_pdu, pdu_length,
 166                                   sig);
 167 }
 168
 169 static NTSTATUS gensec_spnego_sign_packet(struct gensec_security *gensec_security,
 170                                           TALLOC_CTX *mem_ctx,
 171                                           const uint8_t *data, size_t length,
 172                                           const uint8_t *whole_pdu, size_t pdu_length,
 173                                           DATA_BLOB *sig)
 174 {
 175         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 176
 177         if (spnego_state->state_position != SPNEGO_DONE
 178             && spnego_state->state_position != SPNEGO_FALLBACK) {
 179                 return NT_STATUS_INVALID_PARAMETER;
 180         }
 181
 182         return gensec_sign_packet(spnego_state->sub_sec_security,
 183                                   mem_ctx,
 184                                   data, length,
 185                                   whole_pdu, pdu_length,
 186                                   sig);
 187 }
 188
 189 static NTSTATUS gensec_spnego_wrap(struct gensec_security *gensec_security,
 190                                    TALLOC_CTX *mem_ctx,
 191                                    const DATA_BLOB *in,
 192                                    DATA_BLOB *out)
 193 {
 194         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 195
 196         if (spnego_state->state_position != SPNEGO_DONE
 197             && spnego_state->state_position != SPNEGO_FALLBACK) {
 198                 DEBUG(1, ("gensec_spnego_wrap: wrong state for wrap\n"));
 199                 return NT_STATUS_INVALID_PARAMETER;
 200         }
 201
 202         return gensec_wrap(spnego_state->sub_sec_security,
 203                            mem_ctx, in, out);
 204 }
 205
 206 static NTSTATUS gensec_spnego_unwrap(struct gensec_security *gensec_security,
 207                                      TALLOC_CTX *mem_ctx,
 208                                      const DATA_BLOB *in,
 209                                      DATA_BLOB *out)
 210 {
 211         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 212
 213         if (spnego_state->state_position != SPNEGO_DONE
 214             && spnego_state->state_position != SPNEGO_FALLBACK) {
 215                 DEBUG(1, ("gensec_spnego_unwrap: wrong state for unwrap\n"));
 216                 return NT_STATUS_INVALID_PARAMETER;
 217         }
 218
 219         return gensec_unwrap(spnego_state->sub_sec_security,
 220                              mem_ctx, in, out);
 221 }
 222
 223 static NTSTATUS gensec_spnego_wrap_packets(struct gensec_security *gensec_security,
 224                                            TALLOC_CTX *mem_ctx,
 225                                            const DATA_BLOB *in,
 226                                            DATA_BLOB *out,
 227                                            size_t *len_processed)
 228 {
 229         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 230
 231         if (spnego_state->state_position != SPNEGO_DONE
 232             && spnego_state->state_position != SPNEGO_FALLBACK) {
 233                 DEBUG(1, ("gensec_spnego_wrap: wrong state for wrap\n"));
 234                 return NT_STATUS_INVALID_PARAMETER;
 235         }
 236
 237         return gensec_wrap_packets(spnego_state->sub_sec_security,
 238                                    mem_ctx, in, out,
 239                                    len_processed);
 240 }
 241
 242 static NTSTATUS gensec_spnego_packet_full_request(struct gensec_security *gensec_security,
 243                                                 DATA_BLOB blob, size_t *size)
 244 {
 245         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 246
 247         if (spnego_state->state_position != SPNEGO_DONE
 248             && spnego_state->state_position != SPNEGO_FALLBACK) {
 249                 DEBUG(1, ("gensec_spnego_unwrap: wrong state for unwrap\n"));
 250                 return NT_STATUS_INVALID_PARAMETER;
 251         }
 252
 253         return gensec_packet_full_request(spnego_state->sub_sec_security,
 254                                           blob, size);
 255 }
 256
 257 static NTSTATUS gensec_spnego_unwrap_packets(struct gensec_security *gensec_security,
 258                                              TALLOC_CTX *mem_ctx,
 259                                              const DATA_BLOB *in,
 260                                              DATA_BLOB *out,
 261                                              size_t *len_processed)
 262 {
 263         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 264
 265         if (spnego_state->state_position != SPNEGO_DONE
 266             && spnego_state->state_position != SPNEGO_FALLBACK) {
 267                 DEBUG(1, ("gensec_spnego_unwrap: wrong state for unwrap\n"));
 268                 return NT_STATUS_INVALID_PARAMETER;
 269         }
 270
 271         return gensec_unwrap_packets(spnego_state->sub_sec_security,
 272                                      mem_ctx, in, out,
 273                                      len_processed);
 274 }
 275
 276 static size_t gensec_spnego_sig_size(struct gensec_security *gensec_security, size_t data_size)
 277 {
 278         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 279
 280         if (spnego_state->state_position != SPNEGO_DONE
 281             && spnego_state->state_position != SPNEGO_FALLBACK) {
 282                 return 0;
 283         }
 284
 285         return gensec_sig_size(spnego_state->sub_sec_security, data_size);
 286 }
 287
 288 static size_t gensec_spnego_max_input_size(struct gensec_security *gensec_security)
 289 {
 290         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 291
 292         if (spnego_state->state_position != SPNEGO_DONE
 293             && spnego_state->state_position != SPNEGO_FALLBACK) {
 294                 return 0;
 295         }
 296
 297         return gensec_max_input_size(spnego_state->sub_sec_security);
 298 }
 299
 300 static size_t gensec_spnego_max_wrapped_size(struct gensec_security *gensec_security)
 301 {
 302         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 303
 304         if (spnego_state->state_position != SPNEGO_DONE
 305             && spnego_state->state_position != SPNEGO_FALLBACK) {
 306                 return 0;
 307         }
 308
 309         return gensec_max_wrapped_size(spnego_state->sub_sec_security);
 310 }
 311
 312 static NTSTATUS gensec_spnego_session_key(struct gensec_security *gensec_security,
 313                                           TALLOC_CTX *mem_ctx,
 314                                           DATA_BLOB *session_key)
 315 {
 316         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 317         if (!spnego_state->sub_sec_security) {
 318                 return NT_STATUS_INVALID_PARAMETER;
 319         }
 320
 321         return gensec_session_key(spnego_state->sub_sec_security,
 322                                   mem_ctx,
 323                                   session_key);
 324 }
 325
 326 static NTSTATUS gensec_spnego_session_info(struct gensec_security *gensec_security,
 327                                            TALLOC_CTX *mem_ctx,
 328                                            struct auth_session_info **session_info)
 329 {
 330         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 331         if (!spnego_state->sub_sec_security) {
 332                 return NT_STATUS_INVALID_PARAMETER;
 333         }
 334
 335         return gensec_session_info(spnego_state->sub_sec_security,
 336                                    mem_ctx,
 337                                    session_info);
 338 }
 339
 340 /** Fallback to another GENSEC mechanism, based on magic strings
 341  *
 342  * This is the 'fallback' case, where we don't get SPNEGO, and have to
 343  * try all the other options (and hope they all have a magic string
 344  * they check)
 345 */
 346
 347 static NTSTATUS gensec_spnego_server_try_fallback(struct gensec_security *gensec_security,
 348                                                   struct spnego_state *spnego_state,
 349                                                   struct tevent_context *ev,
 350                                                   TALLOC_CTX *out_mem_ctx,
 351                                                   const DATA_BLOB in, DATA_BLOB *out)
 352 {
 353         int i,j;
 354         struct gensec_security_ops **all_ops
 355                 = gensec_security_mechs(gensec_security, out_mem_ctx);
 356         for (i=0; all_ops[i]; i++) {
 357                 bool is_spnego;
 358                 NTSTATUS nt_status;
 359
 360                 if (gensec_security != NULL &&
 361                                 !gensec_security_ops_enabled(all_ops[i], gensec_security))
 362                     continue;
 363
 364                 if (!all_ops[i]->oid) {
 365                         continue;
 366                 }
 367
 368                 is_spnego = false;
 369                 for (j=0; all_ops[i]->oid[j]; j++) {
 370                         if (strcasecmp(GENSEC_OID_SPNEGO,all_ops[i]->oid[j]) == 0) {
 371                                 is_spnego = true;
 372                         }
 373                 }
 374                 if (is_spnego) {
 375                         continue;
 376                 }
 377
 378                 if (!all_ops[i]->magic) {
 379                         continue;
 380                 }
 381
 382                 nt_status = all_ops[i]->magic(gensec_security, &in);
 383                 if (!NT_STATUS_IS_OK(nt_status)) {
 384                         continue;
 385                 }
 386
 387                 spnego_state->state_position = SPNEGO_FALLBACK;
 388
 389                 nt_status = gensec_subcontext_start(spnego_state,
 390                                                     gensec_security,
 391                                                     &spnego_state->sub_sec_security);
 392
 393                 if (!NT_STATUS_IS_OK(nt_status)) {
 394                         return nt_status;
 395                 }
 396                 /* select the sub context */
 397                 nt_status = gensec_start_mech_by_ops(spnego_state->sub_sec_security,
 398                                                      all_ops[i]);
 399                 if (!NT_STATUS_IS_OK(nt_status)) {
 400                         return nt_status;
 401                 }
 402                 nt_status = gensec_update(spnego_state->sub_sec_security,
 403                                           ev, out_mem_ctx, in, out);
 404                 return nt_status;
 405         }
 406         DEBUG(1, ("Failed to parse SPNEGO request\n"));
 407         return NT_STATUS_INVALID_PARAMETER;
 408
 409 }
 410
 411 /*
 412    Parse the netTokenInit, either from the client, to the server, or
 413    from the server to the client.
 414 */
 415
 416 static NTSTATUS gensec_spnego_parse_negTokenInit(struct gensec_security *gensec_security,
 417                                                  struct spnego_state *spnego_state,
 418                                                  TALLOC_CTX *out_mem_ctx,
 419                                                  struct tevent_context *ev,
 420                                                  const char **mechType,
 421                                                  const DATA_BLOB unwrapped_in, DATA_BLOB *unwrapped_out)
 422 {
 423         int i;
 424         NTSTATUS nt_status = NT_STATUS_INVALID_PARAMETER;
 425         DATA_BLOB null_data_blob = data_blob(NULL,0);
 426         bool ok;
 427
 428         const struct gensec_security_ops_wrapper *all_sec
 429                 = gensec_security_by_oid_list(gensec_security,
 430                                               out_mem_ctx,
 431                                               mechType,
 432                                               GENSEC_OID_SPNEGO);
 433
 434         ok = spnego_write_mech_types(spnego_state,
 435                                      mechType,
 436                                      &spnego_state->mech_types);
 437         if (!ok) {
 438                 DEBUG(1, ("SPNEGO: Failed to write mechTypes\n"));
 439                 return NT_STATUS_NO_MEMORY;
 440         }
 441
 442         if (spnego_state->state_position == SPNEGO_SERVER_START) {
 443                 uint32_t j;
 444                 for (j=0; mechType && mechType[j]; j++) {
 445                         for (i=0; all_sec && all_sec[i].op; i++) {
 446                                 if (strcmp(mechType[j], all_sec[i].oid) != 0) {
 447                                         continue;
 448                                 }
 449
 450                                 nt_status = gensec_subcontext_start(spnego_state,
 451                                                                     gensec_security,
 452                                                                     &spnego_state->sub_sec_security);
 453                                 if (!NT_STATUS_IS_OK(nt_status)) {
 454                                         return nt_status;
 455                                 }
 456                                 /* select the sub context */
 457                                 nt_status = gensec_start_mech_by_ops(spnego_state->sub_sec_security,
 458                                                                      all_sec[i].op);
 459                                 if (!NT_STATUS_IS_OK(nt_status)) {
 460                                         talloc_free(spnego_state->sub_sec_security);
 461                                         spnego_state->sub_sec_security = NULL;
 462                                         break;
 463                                 }
 464
 465                                 if (j > 0) {
 466                                         /* no optimistic token */
 467                                         spnego_state->neg_oid = all_sec[i].oid;
 468                                         *unwrapped_out = data_blob_null;
 469                                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 470                                         break;
 471                                 }
 472
 473                                 nt_status = gensec_update(spnego_state->sub_sec_security,
 474                                                           out_mem_ctx,
 475                                                           ev,
 476                                                           unwrapped_in,
 477                                                           unwrapped_out);
 478                                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_PARAMETER) ||
 479                                     NT_STATUS_EQUAL(nt_status, NT_STATUS_CANT_ACCESS_DOMAIN_INFO)) {
 480                                         /* Pretend we never started it (lets the first run find some incompatible demand) */
 481
 482                                         DEBUG(1, ("SPNEGO(%s) NEG_TOKEN_INIT failed to parse contents: %s\n",
 483                                                   spnego_state->sub_sec_security->ops->name, nt_errstr(nt_status)));
 484                                         talloc_free(spnego_state->sub_sec_security);
 485                                         spnego_state->sub_sec_security = NULL;
 486                                         break;
 487                                 }
 488
 489                                 spnego_state->neg_oid = all_sec[i].oid;
 490                                 break;
 491                         }
 492                         if (spnego_state->sub_sec_security) {
 493                                 break;
 494                         }
 495                 }
 496
 497                 if (!spnego_state->sub_sec_security) {
 498                         DEBUG(1, ("SPNEGO: Could not find a suitable mechtype in NEG_TOKEN_INIT\n"));
 499                         return NT_STATUS_INVALID_PARAMETER;
 500                 }
 501         }
 502
 503         /* Having tried any optimistic token from the client (if we
 504          * were the server), if we didn't get anywhere, walk our list
 505          * in our preference order */
 506
 507         if (!spnego_state->sub_sec_security) {
 508                 for (i=0; all_sec && all_sec[i].op; i++) {
 509                         nt_status = gensec_subcontext_start(spnego_state,
 510                                                             gensec_security,
 511                                                             &spnego_state->sub_sec_security);
 512                         if (!NT_STATUS_IS_OK(nt_status)) {
 513                                 return nt_status;
 514                         }
 515                         /* select the sub context */
 516                         nt_status = gensec_start_mech_by_ops(spnego_state->sub_sec_security,
 517                                                              all_sec[i].op);
 518                         if (!NT_STATUS_IS_OK(nt_status)) {
 519                                 talloc_free(spnego_state->sub_sec_security);
 520                                 spnego_state->sub_sec_security = NULL;
 521                                 continue;
 522                         }
 523
 524                         spnego_state->neg_oid = all_sec[i].oid;
 525
 526                         /* only get the helping start blob for the first OID */
 527                         nt_status = gensec_update(spnego_state->sub_sec_security,
 528                                                   out_mem_ctx,
 529                                                   ev,
 530                                                   null_data_blob,
 531                                                   unwrapped_out);
 532
 533                         /* it is likely that a NULL input token will
 534                          * not be liked by most server mechs, but if
 535                          * we are in the client, we want the first
 536                          * update packet to be able to abort the use
 537                          * of this mech */
 538                         if (spnego_state->state_position != SPNEGO_SERVER_START) {
 539                                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_PARAMETER) ||
 540                                     NT_STATUS_EQUAL(nt_status, NT_STATUS_NO_LOGON_SERVERS) ||
 541                                     NT_STATUS_EQUAL(nt_status, NT_STATUS_TIME_DIFFERENCE_AT_DC) ||
 542                                     NT_STATUS_EQUAL(nt_status, NT_STATUS_CANT_ACCESS_DOMAIN_INFO)) {
 543                                         /* Pretend we never started it (lets the first run find some incompatible demand) */
 544
 545                                         DEBUG(3, ("SPNEGO(%s) NEG_TOKEN_INIT failed: %s\n",
 546                                                   spnego_state->sub_sec_security->ops->name, nt_errstr(nt_status)));
 547                                         talloc_free(spnego_state->sub_sec_security);
 548                                         spnego_state->sub_sec_security = NULL;
 549                                         continue;
 550                                 }
 551                         }
 552
 553                         break;
 554                 }
 555         }
 556
 557         if (spnego_state->sub_sec_security) {
 558                 /* it is likely that a NULL input token will
 559                  * not be liked by most server mechs, but this
 560                  * does the right thing in the CIFS client.
 561                  * just push us along the merry-go-round
 562                  * again, and hope for better luck next
 563                  * time */
 564
 565                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_PARAMETER)) {
 566                         *unwrapped_out = data_blob(NULL, 0);
 567                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 568                 }
 569
 570                 if (!NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_PARAMETER)
 571                     && !NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)
 572                     && !NT_STATUS_IS_OK(nt_status)) {
 573                         DEBUG(1, ("SPNEGO(%s) NEG_TOKEN_INIT failed: %s\n",
 574                                   spnego_state->sub_sec_security->ops->name, nt_errstr(nt_status)));
 575                         talloc_free(spnego_state->sub_sec_security);
 576                         spnego_state->sub_sec_security = NULL;
 577
 578                         /* We started the mech correctly, and the
 579                          * input from the other side was valid.
 580                          * Return the error (say bad password, invalid
 581                          * ticket) */
 582                         return nt_status;
 583                 }
 584
 585
 586                 return nt_status; /* OK, INVALID_PARAMETER ore MORE PROCESSING */
 587         }
 588
 589         DEBUG(1, ("SPNEGO: Could not find a suitable mechtype in NEG_TOKEN_INIT\n"));
 590         /* we could re-negotiate here, but it would only work
 591          * if the client or server lied about what it could
 592          * support the first time.  Lets keep this code to
 593          * reality */
 594
 595         return nt_status;
 596 }
 597
 598 /** create a negTokenInit
 599  *
 600  * This is the same packet, no matter if the client or server sends it first, but it is always the first packet
 601 */
 602 static NTSTATUS gensec_spnego_create_negTokenInit(struct gensec_security *gensec_security,
 603                                                   struct spnego_state *spnego_state,
 604                                                   TALLOC_CTX *out_mem_ctx,
 605                                                   struct tevent_context *ev,
 606                                                   const DATA_BLOB in, DATA_BLOB *out)
 607 {
 608         int i;
 609         NTSTATUS nt_status = NT_STATUS_INVALID_PARAMETER;
 610         DATA_BLOB null_data_blob = data_blob(NULL,0);
 611         const char **mechTypes = NULL;
 612         DATA_BLOB unwrapped_out = data_blob(NULL, 0);
 613         const struct gensec_security_ops_wrapper *all_sec;
 614
 615         mechTypes = gensec_security_oids(gensec_security,
 616                                          out_mem_ctx, GENSEC_OID_SPNEGO);
 617
 618         all_sec = gensec_security_by_oid_list(gensec_security,
 619                                               out_mem_ctx,
 620                                               mechTypes,
 621                                               GENSEC_OID_SPNEGO);
 622         for (i=0; all_sec && all_sec[i].op; i++) {
 623                 struct spnego_data spnego_out;
 624                 const char **send_mech_types;
 625                 bool ok;
 626
 627                 nt_status = gensec_subcontext_start(spnego_state,
 628                                                     gensec_security,
 629                                                     &spnego_state->sub_sec_security);
 630                 if (!NT_STATUS_IS_OK(nt_status)) {
 631                         return nt_status;
 632                 }
 633                 /* select the sub context */
 634                 nt_status = gensec_start_mech_by_ops(spnego_state->sub_sec_security,
 635                                                      all_sec[i].op);
 636                 if (!NT_STATUS_IS_OK(nt_status)) {
 637                         talloc_free(spnego_state->sub_sec_security);
 638                         spnego_state->sub_sec_security = NULL;
 639                         continue;
 640                 }
 641
 642                 /* In the client, try and produce the first (optimistic) packet */
 643                 if (spnego_state->state_position == SPNEGO_CLIENT_START) {
 644                         nt_status = gensec_update(spnego_state->sub_sec_security,
 645                                                   out_mem_ctx,
 646                                                   ev,
 647                                                   null_data_blob,
 648                                                   &unwrapped_out);
 649
 650                         if (!NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)
 651                             && !NT_STATUS_IS_OK(nt_status)) {
 652                                 DEBUG(1, ("SPNEGO(%s) creating NEG_TOKEN_INIT failed: %s\n",
 653                                           spnego_state->sub_sec_security->ops->name, nt_errstr(nt_status)));
 654                                 talloc_free(spnego_state->sub_sec_security);
 655                                 spnego_state->sub_sec_security = NULL;
 656                                 /* Pretend we never started it (lets the first run find some incompatible demand) */
 657
 658                                 continue;
 659                         }
 660                 }
 661
 662                 spnego_out.type = SPNEGO_NEG_TOKEN_INIT;
 663
 664                 send_mech_types = gensec_security_oids_from_ops_wrapped(out_mem_ctx,
 665                                                                         &all_sec[i]);
 666
 667                 ok = spnego_write_mech_types(spnego_state,
 668                                              send_mech_types,
 669                                              &spnego_state->mech_types);
 670                 if (!ok) {
 671                         DEBUG(1, ("SPNEGO: Failed to write mechTypes\n"));
 672                         return NT_STATUS_NO_MEMORY;
 673                 }
 674
 675                 /* List the remaining mechs as options */
 676                 spnego_out.negTokenInit.mechTypes = send_mech_types;
 677                 spnego_out.negTokenInit.reqFlags = null_data_blob;
 678                 spnego_out.negTokenInit.reqFlagsPadding = 0;
 679
 680                 if (spnego_state->state_position == SPNEGO_SERVER_START) {
 681                         spnego_out.negTokenInit.mechListMIC
 682                                 = data_blob_string_const(ADS_IGNORE_PRINCIPAL);
 683                 } else {
 684                         spnego_out.negTokenInit.mechListMIC = null_data_blob;
 685                 }
 686
 687                 spnego_out.negTokenInit.mechToken = unwrapped_out;
 688
 689                 if (spnego_write_data(out_mem_ctx, out, &spnego_out) == -1) {
 690                         DEBUG(1, ("Failed to write NEG_TOKEN_INIT\n"));
 691                                 return NT_STATUS_INVALID_PARAMETER;
 692                 }
 693
 694                 /* set next state */
 695                 spnego_state->neg_oid = all_sec[i].oid;
 696
 697                 if (NT_STATUS_IS_OK(nt_status)) {
 698                         spnego_state->no_response_expected = true;
 699                 }
 700
 701                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 702         }
 703         talloc_free(spnego_state->sub_sec_security);
 704         spnego_state->sub_sec_security = NULL;
 705
 706         DEBUG(1, ("Failed to setup SPNEGO negTokenInit request: %s\n", nt_errstr(nt_status)));
 707         return NT_STATUS_INVALID_PARAMETER;
 708 }
 709
 710
 711 /** create a server negTokenTarg
 712  *
 713  * This is the case, where the client is the first one who sends data
 714 */
 715
 716 static NTSTATUS gensec_spnego_server_negTokenTarg(struct gensec_security *gensec_security,
 717                                                   struct spnego_state *spnego_state,
 718                                                   TALLOC_CTX *out_mem_ctx,
 719                                                   NTSTATUS nt_status,
 720                                                   const DATA_BLOB unwrapped_out,
 721                                                   DATA_BLOB mech_list_mic,
 722                                                   DATA_BLOB *out)
 723 {
 724         struct spnego_data spnego_out;
 725         DATA_BLOB null_data_blob = data_blob(NULL, 0);
 726
 727         /* compose reply */
 728         spnego_out.type = SPNEGO_NEG_TOKEN_TARG;
 729         spnego_out.negTokenTarg.responseToken = unwrapped_out;
 730         spnego_out.negTokenTarg.mechListMIC = null_data_blob;
 731         spnego_out.negTokenTarg.supportedMech = NULL;
 732
 733         if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 734                 spnego_out.negTokenTarg.supportedMech = spnego_state->neg_oid;
 735                 spnego_out.negTokenTarg.negResult = SPNEGO_ACCEPT_INCOMPLETE;
 736                 spnego_state->state_position = SPNEGO_SERVER_TARG;
 737         } else if (NT_STATUS_IS_OK(nt_status)) {
 738                 if (unwrapped_out.data) {
 739                         spnego_out.negTokenTarg.supportedMech = spnego_state->neg_oid;
 740                 }
 741                 spnego_out.negTokenTarg.negResult = SPNEGO_ACCEPT_COMPLETED;
 742                 spnego_out.negTokenTarg.mechListMIC = mech_list_mic;
 743                 spnego_state->state_position = SPNEGO_DONE;
 744         } else {
 745                 spnego_out.negTokenTarg.negResult = SPNEGO_REJECT;
 746                 DEBUG(2, ("SPNEGO login failed: %s\n", nt_errstr(nt_status)));
 747                 spnego_state->state_position = SPNEGO_DONE;
 748         }
 749
 750         if (spnego_write_data(out_mem_ctx, out, &spnego_out) == -1) {
 751                 DEBUG(1, ("Failed to write SPNEGO reply to NEG_TOKEN_TARG\n"));
 752                 return NT_STATUS_INVALID_PARAMETER;
 753         }
 754
 755         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_TARG;
 756
 757         return nt_status;
 758 }
 759
 760
 761 static NTSTATUS gensec_spnego_update(struct gensec_security *gensec_security, TALLOC_CTX *out_mem_ctx,
 762                                      struct tevent_context *ev,
 763                                      const DATA_BLOB in, DATA_BLOB *out)
 764 {
 765         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 766         DATA_BLOB null_data_blob = data_blob(NULL, 0);
 767         DATA_BLOB mech_list_mic = data_blob(NULL, 0);
 768         DATA_BLOB unwrapped_out = data_blob(NULL, 0);
 769         struct spnego_data spnego_out;
 770         struct spnego_data spnego;
 771
 772         ssize_t len;
 773
 774         *out = data_blob(NULL, 0);
 775
 776         if (!out_mem_ctx) {
 777                 out_mem_ctx = spnego_state;
 778         }
 779
 780         /* and switch into the state machine */
 781
 782         switch (spnego_state->state_position) {
 783         case SPNEGO_FALLBACK:
 784                 return gensec_update(spnego_state->sub_sec_security, ev,
 785                                      out_mem_ctx, in, out);
 786         case SPNEGO_SERVER_START:
 787         {
 788                 NTSTATUS nt_status;
 789                 if (in.length) {
 790
 791                         len = spnego_read_data(gensec_security, in, &spnego);
 792                         if (len == -1) {
 793                                 return gensec_spnego_server_try_fallback(gensec_security, spnego_state,
 794                                                                          out_mem_ctx, ev, in, out);
 795                         }
 796                         /* client sent NegTargetInit, we send NegTokenTarg */
 797
 798                         /* OK, so it's real SPNEGO, check the packet's the one we expect */
 799                         if (spnego.type != spnego_state->expected_packet) {
 800                                 DEBUG(1, ("Invalid SPNEGO request: %d, expected %d\n", spnego.type,
 801                                           spnego_state->expected_packet));
 802                                 dump_data(1, in.data, in.length);
 803                                 spnego_free_data(&spnego);
 804                                 return NT_STATUS_INVALID_PARAMETER;
 805                         }
 806
 807                         nt_status = gensec_spnego_parse_negTokenInit(gensec_security,
 808                                                                      spnego_state,
 809                                                                      out_mem_ctx,
 810                                                                      ev,
 811                                                                      spnego.negTokenInit.mechTypes,
 812                                                                      spnego.negTokenInit.mechToken,
 813                                                                      &unwrapped_out);
 814
 815                         nt_status = gensec_spnego_server_negTokenTarg(gensec_security,
 816                                                                       spnego_state,
 817                                                                       out_mem_ctx,
 818                                                                       nt_status,
 819                                                                       unwrapped_out,
 820                                                                       null_data_blob,
 821                                                                       out);
 822
 823                         spnego_free_data(&spnego);
 824
 825                         return nt_status;
 826                 } else {
 827                         nt_status = gensec_spnego_create_negTokenInit(gensec_security, spnego_state,
 828                                                                       out_mem_ctx, ev, in, out);
 829                         spnego_state->state_position = SPNEGO_SERVER_START;
 830                         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_INIT;
 831                         return nt_status;
 832                 }
 833         }
 834
 835         case SPNEGO_CLIENT_START:
 836         {
 837                 /* The server offers a list of mechanisms */
 838
 839                 const char *my_mechs[] = {NULL, NULL};
 840                 NTSTATUS nt_status = NT_STATUS_INVALID_PARAMETER;
 841
 842                 if (!in.length) {
 843                         /* client to produce negTokenInit */
 844                         nt_status = gensec_spnego_create_negTokenInit(gensec_security, spnego_state,
 845                                                                       out_mem_ctx, ev, in, out);
 846                         spnego_state->state_position = SPNEGO_CLIENT_TARG;
 847                         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_TARG;
 848                         return nt_status;
 849                 }
 850
 851                 len = spnego_read_data(gensec_security, in, &spnego);
 852
 853                 if (len == -1) {
 854                         DEBUG(1, ("Invalid SPNEGO request:\n"));
 855                         dump_data(1, in.data, in.length);
 856                         return NT_STATUS_INVALID_PARAMETER;
 857                 }
 858
 859                 /* OK, so it's real SPNEGO, check the packet's the one we expect */
 860                 if (spnego.type != spnego_state->expected_packet) {
 861                         DEBUG(1, ("Invalid SPNEGO request: %d, expected %d\n", spnego.type,
 862                                   spnego_state->expected_packet));
 863                         dump_data(1, in.data, in.length);
 864                         spnego_free_data(&spnego);
 865                         return NT_STATUS_INVALID_PARAMETER;
 866                 }
 867
 868                 if (spnego.negTokenInit.targetPrincipal
 869                     && strcmp(spnego.negTokenInit.targetPrincipal, ADS_IGNORE_PRINCIPAL) != 0) {
 870                         DEBUG(5, ("Server claims it's principal name is %s\n", spnego.negTokenInit.targetPrincipal));
 871                         if (lpcfg_client_use_spnego_principal(gensec_security->settings->lp_ctx)) {
 872                                 gensec_set_target_principal(gensec_security, spnego.negTokenInit.targetPrincipal);
 873                         }
 874                 }
 875
 876                 nt_status = gensec_spnego_parse_negTokenInit(gensec_security,
 877                                                              spnego_state,
 878                                                              out_mem_ctx,
 879                                                              ev,
 880                                                              spnego.negTokenInit.mechTypes,
 881                                                              spnego.negTokenInit.mechToken,
 882                                                              &unwrapped_out);
 883
 884                 if (!NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED) && !NT_STATUS_IS_OK(nt_status)) {
 885                         spnego_free_data(&spnego);
 886                         return nt_status;
 887                 }
 888
 889                 my_mechs[0] = spnego_state->neg_oid;
 890                 /* compose reply */
 891                 spnego_out.type = SPNEGO_NEG_TOKEN_INIT;
 892                 spnego_out.negTokenInit.mechTypes = my_mechs;
 893                 spnego_out.negTokenInit.reqFlags = null_data_blob;
 894                 spnego_out.negTokenInit.reqFlagsPadding = 0;
 895                 spnego_out.negTokenInit.mechListMIC = null_data_blob;
 896                 spnego_out.negTokenInit.mechToken = unwrapped_out;
 897
 898                 if (spnego_write_data(out_mem_ctx, out, &spnego_out) == -1) {
 899                         DEBUG(1, ("Failed to write SPNEGO reply to NEG_TOKEN_INIT\n"));
 900                                 return NT_STATUS_INVALID_PARAMETER;
 901                 }
 902
 903                 /* set next state */
 904                 spnego_state->expected_packet = SPNEGO_NEG_TOKEN_TARG;
 905                 spnego_state->state_position = SPNEGO_CLIENT_TARG;
 906
 907                 if (NT_STATUS_IS_OK(nt_status)) {
 908                         spnego_state->no_response_expected = true;
 909                 }
 910
 911                 spnego_free_data(&spnego);
 912                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 913         }
 914         case SPNEGO_SERVER_TARG:
 915         {
 916                 NTSTATUS nt_status;
 917                 bool new_spnego = false;
 918
 919                 if (!in.length) {
 920                         return NT_STATUS_INVALID_PARAMETER;
 921                 }
 922
 923                 len = spnego_read_data(gensec_security, in, &spnego);
 924
 925                 if (len == -1) {
 926                         DEBUG(1, ("Invalid SPNEGO request:\n"));
 927                         dump_data(1, in.data, in.length);
 928                         return NT_STATUS_INVALID_PARAMETER;
 929                 }
 930
 931                 /* OK, so it's real SPNEGO, check the packet's the one we expect */
 932                 if (spnego.type != spnego_state->expected_packet) {
 933                         DEBUG(1, ("Invalid SPNEGO request: %d, expected %d\n", spnego.type,
 934                                   spnego_state->expected_packet));
 935                         dump_data(1, in.data, in.length);
 936                         spnego_free_data(&spnego);
 937                         return NT_STATUS_INVALID_PARAMETER;
 938                 }
 939
 940                 if (!spnego_state->sub_sec_security) {
 941                         DEBUG(1, ("SPNEGO: Did not setup a mech in NEG_TOKEN_INIT\n"));
 942                         spnego_free_data(&spnego);
 943                         return NT_STATUS_INVALID_PARAMETER;
 944                 }
 945
 946                 nt_status = gensec_update(spnego_state->sub_sec_security,
 947                                           out_mem_ctx, ev,
 948                                           spnego.negTokenTarg.responseToken,
 949                                           &unwrapped_out);
 950                 if (NT_STATUS_IS_OK(nt_status) && spnego.negTokenTarg.mechListMIC.length > 0) {
 951                         new_spnego = true;
 952                         nt_status = gensec_check_packet(spnego_state->sub_sec_security,
 953                                                         spnego_state->mech_types.data,
 954                                                         spnego_state->mech_types.length,
 955                                                         spnego_state->mech_types.data,
 956                                                         spnego_state->mech_types.length,
 957                                                         &spnego.negTokenTarg.mechListMIC);
 958                         if (!NT_STATUS_IS_OK(nt_status)) {
 959                                 DEBUG(2,("GENSEC SPNEGO: failed to verify mechListMIC: %s\n",
 960                                         nt_errstr(nt_status)));
 961                         }
 962                 }
 963                 if (NT_STATUS_IS_OK(nt_status) && new_spnego) {
 964                         nt_status = gensec_sign_packet(spnego_state->sub_sec_security,
 965                                                        out_mem_ctx,
 966                                                        spnego_state->mech_types.data,
 967                                                        spnego_state->mech_types.length,
 968                                                        spnego_state->mech_types.data,
 969                                                        spnego_state->mech_types.length,
 970                                                        &mech_list_mic);
 971                         if (!NT_STATUS_IS_OK(nt_status)) {
 972                                 DEBUG(2,("GENSEC SPNEGO: failed to sign mechListMIC: %s\n",
 973                                         nt_errstr(nt_status)));
 974                         }
 975                 }
 976
 977                 nt_status = gensec_spnego_server_negTokenTarg(gensec_security,
 978                                                               spnego_state,
 979                                                               out_mem_ctx,
 980                                                               nt_status,
 981                                                               unwrapped_out,
 982                                                               mech_list_mic,
 983                                                               out);
 984
 985                 spnego_free_data(&spnego);
 986
 987                 return nt_status;
 988         }
 989         case SPNEGO_CLIENT_TARG:
 990         {
 991                 NTSTATUS nt_status;
 992                 if (!in.length) {
 993                         return NT_STATUS_INVALID_PARAMETER;
 994                 }
 995
 996                 len = spnego_read_data(gensec_security, in, &spnego);
 997
 998                 if (len == -1) {
 999                         DEBUG(1, ("Invalid SPNEGO request:\n"));
1000                         dump_data(1, in.data, in.length);
1001                         return NT_STATUS_INVALID_PARAMETER;
1002                 }
1003
1004                 /* OK, so it's real SPNEGO, check the packet's the one we expect */
1005                 if (spnego.type != spnego_state->expected_packet) {
1006                         DEBUG(1, ("Invalid SPNEGO request: %d, expected %d\n", spnego.type,
1007                                   spnego_state->expected_packet));
1008                         dump_data(1, in.data, in.length);
1009                         spnego_free_data(&spnego);
1010                         return NT_STATUS_INVALID_PARAMETER;
1011                 }
1012
1013                 if (spnego.negTokenTarg.negResult == SPNEGO_REJECT) {
1014                         spnego_free_data(&spnego);
1015                         return NT_STATUS_ACCESS_DENIED;
1016                 }
1017
1018                 /* Server didn't like our choice of mech, and chose something else */
1019                 if ((spnego.negTokenTarg.negResult == SPNEGO_ACCEPT_INCOMPLETE) &&
1020                     spnego.negTokenTarg.supportedMech &&
1021                     strcmp(spnego.negTokenTarg.supportedMech, spnego_state->neg_oid) != 0) {
1022                         DEBUG(3,("GENSEC SPNEGO: client preferred mech (%s) not accepted, server wants: %s\n",
1023                                  gensec_get_name_by_oid(gensec_security, spnego.negTokenTarg.supportedMech),
1024                                  gensec_get_name_by_oid(gensec_security, spnego_state->neg_oid)));
1025
1026                         talloc_free(spnego_state->sub_sec_security);
1027                         nt_status = gensec_subcontext_start(spnego_state,
1028                                                             gensec_security,
1029                                                             &spnego_state->sub_sec_security);
1030                         if (!NT_STATUS_IS_OK(nt_status)) {
1031                                 spnego_free_data(&spnego);
1032                                 return nt_status;
1033                         }
1034                         /* select the sub context */
1035                         nt_status = gensec_start_mech_by_oid(spnego_state->sub_sec_security,
1036                                                              spnego.negTokenTarg.supportedMech);
1037                         if (!NT_STATUS_IS_OK(nt_status)) {
1038                                 spnego_free_data(&spnego);
1039                                 return nt_status;
1040                         }
1041
1042                         nt_status = gensec_update(spnego_state->sub_sec_security,
1043                                                   out_mem_ctx, ev,
1044                                                   spnego.negTokenTarg.responseToken,
1045                                                   &unwrapped_out);
1046                         spnego_state->neg_oid = talloc_strdup(spnego_state, spnego.negTokenTarg.supportedMech);
1047                 } else if (spnego_state->no_response_expected) {
1048                         if (spnego.negTokenTarg.negResult != SPNEGO_ACCEPT_COMPLETED) {
1049                                 DEBUG(3,("GENSEC SPNEGO: client GENSEC accepted, but server rejected (bad password?)\n"));
1050                                 nt_status = NT_STATUS_INVALID_PARAMETER;
1051                         } else if (spnego.negTokenTarg.responseToken.length) {
1052                                 DEBUG(2,("GENSEC SPNEGO: client GENSEC accepted, but server continued negotiation!\n"));
1053                                 nt_status = NT_STATUS_INVALID_PARAMETER;
1054                         } else {
1055                                 nt_status = NT_STATUS_OK;
1056                         }
1057                         if (NT_STATUS_IS_OK(nt_status) && spnego.negTokenTarg.mechListMIC.length > 0) {
1058                                 nt_status = gensec_check_packet(spnego_state->sub_sec_security,
1059                                                                 spnego_state->mech_types.data,
1060                                                                 spnego_state->mech_types.length,
1061                                                                 spnego_state->mech_types.data,
1062                                                                 spnego_state->mech_types.length,
1063                                                                 &spnego.negTokenTarg.mechListMIC);
1064                                 if (!NT_STATUS_IS_OK(nt_status)) {
1065                                         DEBUG(2,("GENSEC SPNEGO: failed to verify mechListMIC: %s\n",
1066                                                 nt_errstr(nt_status)));
1067                                 }
1068                         }
1069                 } else {
1070                         bool new_spnego = false;
1071
1072                         nt_status = gensec_update(spnego_state->sub_sec_security,
1073                                                   out_mem_ctx, ev,
1074                                                   spnego.negTokenTarg.responseToken,
1075                                                   &unwrapped_out);
1076
1077                         if (NT_STATUS_IS_OK(nt_status)
1078                             && spnego.negTokenTarg.negResult != SPNEGO_ACCEPT_COMPLETED) {
1079                                 new_spnego = gensec_have_feature(spnego_state->sub_sec_security,
1080                                                                  GENSEC_FEATURE_NEW_SPNEGO);
1081                         }
1082                         if (NT_STATUS_IS_OK(nt_status) && new_spnego) {
1083                                 nt_status = gensec_sign_packet(spnego_state->sub_sec_security,
1084                                                                out_mem_ctx,
1085                                                                spnego_state->mech_types.data,
1086                                                                spnego_state->mech_types.length,
1087                                                                spnego_state->mech_types.data,
1088                                                                spnego_state->mech_types.length,
1089                                                                &mech_list_mic);
1090                                 if (!NT_STATUS_IS_OK(nt_status)) {
1091                                         DEBUG(2,("GENSEC SPNEGO: failed to sign mechListMIC: %s\n",
1092                                                 nt_errstr(nt_status)));
1093                                 }
1094                         }
1095                         if (NT_STATUS_IS_OK(nt_status)) {
1096                                 spnego_state->no_response_expected = true;
1097                         }
1098                 }
1099
1100                 spnego_free_data(&spnego);
1101
1102                 if (!NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)
1103                         && !NT_STATUS_IS_OK(nt_status)) {
1104                         DEBUG(1, ("SPNEGO(%s) login failed: %s\n",
1105                                   spnego_state->sub_sec_security->ops->name,
1106                                   nt_errstr(nt_status)));
1107                         return nt_status;
1108                 }
1109
1110                 if (unwrapped_out.length || mech_list_mic.length) {
1111                         /* compose reply */
1112                         spnego_out.type = SPNEGO_NEG_TOKEN_TARG;
1113                         spnego_out.negTokenTarg.negResult = SPNEGO_NONE_RESULT;
1114                         spnego_out.negTokenTarg.supportedMech = NULL;
1115                         spnego_out.negTokenTarg.responseToken = unwrapped_out;
1116                         spnego_out.negTokenTarg.mechListMIC = mech_list_mic;
1117
1118                         if (spnego_write_data(out_mem_ctx, out, &spnego_out) == -1) {
1119                                 DEBUG(1, ("Failed to write SPNEGO reply to NEG_TOKEN_TARG\n"));
1120                                 return NT_STATUS_INVALID_PARAMETER;
1121                         }
1122
1123                         spnego_state->state_position = SPNEGO_CLIENT_TARG;
1124                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
1125                 } else {
1126
1127                         /* all done - server has accepted, and we agree */
1128                         *out = null_data_blob;
1129
1130                         if (spnego.negTokenTarg.negResult != SPNEGO_ACCEPT_COMPLETED) {
1131                                 /* unless of course it did not accept */
1132                                 DEBUG(1,("gensec_update ok but not accepted\n"));
1133                                 nt_status = NT_STATUS_INVALID_PARAMETER;
1134                         }
1135
1136                         spnego_state->state_position = SPNEGO_DONE;
1137                 }
1138
1139                 return nt_status;
1140         }
1141         case SPNEGO_DONE:
1142                 /* We should not be called after we are 'done' */
1143                 return NT_STATUS_INVALID_PARAMETER;
1144         }
1145         return NT_STATUS_INVALID_PARAMETER;
1146 }
1147
1148 static NTSTATUS gensec_spnego_update_in(struct gensec_security *gensec_security,
1149                                         const DATA_BLOB in, DATA_BLOB *full_in)
1150 {
1151         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
1152         size_t expected;
1153         NTSTATUS status;
1154         bool ok;
1155
1156         *full_in = data_blob_null;
1157
1158         if (spnego_state->in_needed == 0) {
1159                 size_t size = 0;
1160
1161                 /*
1162                  * try to work out the size of the full
1163                  * input token, it might be fragmented
1164                  */
1165                 status = asn1_peek_full_tag(in,  ASN1_APPLICATION(0), &size);
1166                 if (!NT_STATUS_IS_OK(status) &&
1167                     !NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
1168                         status = asn1_peek_full_tag(in, ASN1_CONTEXT(1), &size);
1169                 }
1170
1171                 if (NT_STATUS_IS_OK(status) ||
1172                     NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
1173                         spnego_state->in_needed = size;
1174                 } else {
1175                         /*
1176                          * If it is not an asn1 message
1177                          * just call the next layer.
1178                          */
1179                         spnego_state->in_needed = in.length;
1180                 }
1181         }
1182
1183         if (spnego_state->in_needed > UINT16_MAX) {
1184                 /*
1185                  * limit the incoming message to 0xFFFF
1186                  * to avoid DoS attacks.
1187                  */
1188                 return NT_STATUS_INVALID_BUFFER_SIZE;
1189         }
1190
1191         if ((spnego_state->in_needed > 0) && (in.length == 0)) {
1192                 /*
1193                  * If we reach this, we know we got at least
1194                  * part of an asn1 message, getting 0 means
1195                  * the remote peer wants us to spin.
1196                  */
1197                 return NT_STATUS_INVALID_PARAMETER;
1198         }
1199
1200         expected = spnego_state->in_needed - spnego_state->in_frag.length;
1201         if (in.length > expected) {
1202                 /*
1203                  * we got more than expected
1204                  */
1205                 return NT_STATUS_INVALID_PARAMETER;
1206         }
1207
1208         if (in.length == spnego_state->in_needed) {
1209                 /*
1210                  * if the in.length contains the full blob
1211                  * we are done.
1212                  *
1213                  * Note: this implies spnego_state->in_frag.length == 0,
1214                  *       but we do not need to check this explicitly
1215                  *       because we already know that we did not get
1216                  *       more than expected.
1217                  */
1218                 *full_in = in;
1219                 return NT_STATUS_OK;
1220         }
1221
1222         ok = data_blob_append(spnego_state, &spnego_state->in_frag,
1223                               in.data, in.length);
1224         if (!ok) {
1225                 return NT_STATUS_NO_MEMORY;
1226         }
1227
1228         if (spnego_state->in_needed > spnego_state->in_frag.length) {
1229                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
1230         }
1231
1232         *full_in = spnego_state->in_frag;
1233         return NT_STATUS_OK;
1234 }
1235
1236 static NTSTATUS gensec_spnego_update_out(struct gensec_security *gensec_security,
1237                                          TALLOC_CTX *out_mem_ctx,
1238                                          DATA_BLOB *_out)
1239 {
1240         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
1241         DATA_BLOB out = data_blob_null;
1242
1243         *_out = data_blob_null;
1244
1245         if (spnego_state->out_frag.length == 0) {
1246                 return spnego_state->out_status;
1247         }
1248
1249         /*
1250          * There is still more data to be delivered
1251          * to the remote peer.
1252          */
1253
1254         if (spnego_state->out_frag.length <= spnego_state->out_max_length) {
1255                 /*
1256                  * Fast path, we can deliver everything
1257                  */
1258
1259                 *_out = spnego_state->out_frag;
1260                 talloc_steal(out_mem_ctx, _out->data);
1261                 spnego_state->out_frag = data_blob_null;
1262                 return spnego_state->out_status;
1263         }
1264
1265         out = spnego_state->out_frag;
1266
1267         /*
1268          * copy the remaining bytes
1269          */
1270         spnego_state->out_frag = data_blob_talloc(spnego_state,
1271                                         out.data + spnego_state->out_max_length,
1272                                         out.length - spnego_state->out_max_length);
1273         if (spnego_state->out_frag.data == NULL) {
1274                 return NT_STATUS_NO_MEMORY;
1275         }
1276
1277         /*
1278          * truncate the buffer
1279          */
1280         data_blob_realloc(spnego_state, &out, spnego_state->out_max_length);
1281
1282         talloc_steal(out_mem_ctx, out.data);
1283         *_out = out;
1284         return NT_STATUS_MORE_PROCESSING_REQUIRED;
1285 }
1286
1287 static NTSTATUS gensec_spnego_update_wrapper(struct gensec_security *gensec_security,
1288                                              TALLOC_CTX *out_mem_ctx,
1289                                              struct tevent_context *ev,
1290                                              const DATA_BLOB in, DATA_BLOB *out)
1291 {
1292         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
1293         DATA_BLOB full_in = data_blob_null;
1294         NTSTATUS status;
1295
1296         *out = data_blob_null;
1297
1298         if (spnego_state->out_frag.length > 0) {
1299                 if (in.length > 0) {
1300                         return NT_STATUS_INVALID_PARAMETER;
1301                 }
1302
1303                 return gensec_spnego_update_out(gensec_security,
1304                                                 out_mem_ctx,
1305                                                 out);
1306         }
1307
1308         status = gensec_spnego_update_in(gensec_security,
1309                                          in, &full_in);
1310         if (!NT_STATUS_IS_OK(status)) {
1311                 return status;
1312         }
1313
1314         status = gensec_spnego_update(gensec_security,
1315                                       spnego_state, ev,
1316                                       full_in,
1317                                       &spnego_state->out_frag);
1318         data_blob_free(&spnego_state->in_frag);
1319         spnego_state->in_needed = 0;
1320         if (!NT_STATUS_IS_OK(status) &&
1321             !NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
1322                 return status;
1323         }
1324
1325         spnego_state->out_status = status;
1326
1327         return gensec_spnego_update_out(gensec_security,
1328                                         out_mem_ctx,
1329                                         out);
1330 }
1331
1332 static void gensec_spnego_want_feature(struct gensec_security *gensec_security,
1333                                        uint32_t feature)
1334 {
1335         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
1336
1337         if (!spnego_state || !spnego_state->sub_sec_security) {
1338                 gensec_security->want_features |= feature;
1339                 return;
1340         }
1341
1342         gensec_want_feature(spnego_state->sub_sec_security,
1343                             feature);
1344 }
1345
1346 static bool gensec_spnego_have_feature(struct gensec_security *gensec_security,
1347                                        uint32_t feature)
1348 {
1349         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
1350         if (!spnego_state->sub_sec_security) {
1351                 return false;
1352         }
1353
1354         return gensec_have_feature(spnego_state->sub_sec_security,
1355                                    feature);
1356 }
1357
1358 static const char *gensec_spnego_oids[] = {
1359         GENSEC_OID_SPNEGO,
1360         NULL
1361 };
1362
1363 static const struct gensec_security_ops gensec_spnego_security_ops = {
1364         .name             = "spnego",
1365         .sasl_name        = "GSS-SPNEGO",
1366         .auth_type        = DCERPC_AUTH_TYPE_SPNEGO,
1367         .oid              = gensec_spnego_oids,
1368         .client_start     = gensec_spnego_client_start,
1369         .server_start     = gensec_spnego_server_start,
1370         .update           = gensec_spnego_update_wrapper,
1371         .seal_packet      = gensec_spnego_seal_packet,
1372         .sign_packet      = gensec_spnego_sign_packet,
1373         .sig_size         = gensec_spnego_sig_size,
1374         .max_wrapped_size = gensec_spnego_max_wrapped_size,
1375         .max_input_size   = gensec_spnego_max_input_size,
1376         .check_packet     = gensec_spnego_check_packet,
1377         .unseal_packet    = gensec_spnego_unseal_packet,
1378         .packet_full_request = gensec_spnego_packet_full_request,
1379         .wrap             = gensec_spnego_wrap,
1380         .unwrap           = gensec_spnego_unwrap,
1381         .wrap_packets     = gensec_spnego_wrap_packets,
1382         .unwrap_packets   = gensec_spnego_unwrap_packets,
1383         .session_key      = gensec_spnego_session_key,
1384         .session_info     = gensec_spnego_session_info,
1385         .want_feature     = gensec_spnego_want_feature,
1386         .have_feature     = gensec_spnego_have_feature,
1387         .enabled          = true,
1388         .priority         = GENSEC_SPNEGO
1389 };
1390
1391 _PUBLIC_ NTSTATUS gensec_spnego_init(void)
1392 {
1393         NTSTATUS ret;
1394         ret = gensec_register(&gensec_spnego_security_ops);
1395         if (!NT_STATUS_IS_OK(ret)) {
1396                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1397                         gensec_spnego_security_ops.name));
1398                 return ret;
1399         }
1400
1401         return ret;
1402 }