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 <tevent.h>
  27 #include "lib/util/tevent_ntstatus.h"
  28 #include "../libcli/auth/spnego.h"
  29 #include "librpc/gen_ndr/ndr_dcerpc.h"
  30 #include "auth/credentials/credentials.h"
  31 #include "auth/gensec/gensec.h"
  32 #include "auth/gensec/gensec_internal.h"
  33 #include "param/param.h"
  34 #include "lib/util/asn1.h"
  35 #include "lib/util/base64.h"
  36
  37 #undef strcasecmp
  38
  39 _PUBLIC_ NTSTATUS gensec_spnego_init(TALLOC_CTX *ctx);
  40
  41 enum spnego_state_position {
  42         SPNEGO_SERVER_START,
  43         SPNEGO_CLIENT_START,
  44         SPNEGO_SERVER_TARG,
  45         SPNEGO_CLIENT_TARG,
  46         SPNEGO_FALLBACK,
  47         SPNEGO_DONE
  48 };
  49
  50 struct spnego_state {
  51         enum spnego_message_type expected_packet;
  52         enum spnego_state_position state_position;
  53         struct gensec_security *sub_sec_security;
  54         bool sub_sec_ready;
  55
  56         const char *neg_oid;
  57
  58         DATA_BLOB mech_types;
  59         size_t num_targs;
  60         bool downgraded;
  61         bool mic_requested;
  62         bool needs_mic_sign;
  63         bool needs_mic_check;
  64         bool may_skip_mic_check;
  65         bool done_mic_check;
  66
  67         bool simulate_w2k;
  68
  69         /*
  70          * The following is used to implement
  71          * the update token fragmentation
  72          */
  73         size_t in_needed;
  74         DATA_BLOB in_frag;
  75         size_t out_max_length;
  76         DATA_BLOB out_frag;
  77         NTSTATUS out_status;
  78 };
  79
  80 static void gensec_spnego_update_sub_abort(struct spnego_state *spnego_state)
  81 {
  82         spnego_state->sub_sec_ready = false;
  83         TALLOC_FREE(spnego_state->sub_sec_security);
  84 }
  85
  86 static NTSTATUS gensec_spnego_client_start(struct gensec_security *gensec_security)
  87 {
  88         struct spnego_state *spnego_state;
  89
  90         spnego_state = talloc_zero(gensec_security, struct spnego_state);
  91         if (!spnego_state) {
  92                 return NT_STATUS_NO_MEMORY;
  93         }
  94
  95         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_INIT;
  96         spnego_state->state_position = SPNEGO_CLIENT_START;
  97         spnego_state->sub_sec_security = NULL;
  98         spnego_state->sub_sec_ready = false;
  99         spnego_state->mech_types = data_blob_null;
 100         spnego_state->out_max_length = gensec_max_update_size(gensec_security);
 101         spnego_state->out_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 102
 103         spnego_state->simulate_w2k = gensec_setting_bool(gensec_security->settings,
 104                                                 "spnego", "simulate_w2k", false);
 105
 106         gensec_security->private_data = spnego_state;
 107         return NT_STATUS_OK;
 108 }
 109
 110 static NTSTATUS gensec_spnego_server_start(struct gensec_security *gensec_security)
 111 {
 112         struct spnego_state *spnego_state;
 113
 114         spnego_state = talloc_zero(gensec_security, struct spnego_state);
 115         if (!spnego_state) {
 116                 return NT_STATUS_NO_MEMORY;
 117         }
 118
 119         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_INIT;
 120         spnego_state->state_position = SPNEGO_SERVER_START;
 121         spnego_state->sub_sec_security = NULL;
 122         spnego_state->sub_sec_ready = false;
 123         spnego_state->mech_types = data_blob_null;
 124         spnego_state->out_max_length = gensec_max_update_size(gensec_security);
 125         spnego_state->out_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 126
 127         spnego_state->simulate_w2k = gensec_setting_bool(gensec_security->settings,
 128                                                 "spnego", "simulate_w2k", false);
 129
 130         gensec_security->private_data = spnego_state;
 131         return NT_STATUS_OK;
 132 }
 133
 134 /** Fallback to another GENSEC mechanism, based on magic strings
 135  *
 136  * This is the 'fallback' case, where we don't get SPNEGO, and have to
 137  * try all the other options (and hope they all have a magic string
 138  * they check)
 139 */
 140
 141 static NTSTATUS gensec_spnego_server_try_fallback(struct gensec_security *gensec_security,
 142                                                   struct spnego_state *spnego_state,
 143                                                   struct tevent_context *ev,
 144                                                   TALLOC_CTX *out_mem_ctx,
 145                                                   const DATA_BLOB in, DATA_BLOB *out)
 146 {
 147         int i,j;
 148         const struct gensec_security_ops **all_ops;
 149
 150         all_ops = gensec_security_mechs(gensec_security, out_mem_ctx);
 151
 152         for (i=0; all_ops && all_ops[i]; i++) {
 153                 bool is_spnego;
 154                 NTSTATUS nt_status;
 155
 156                 if (gensec_security != NULL &&
 157                                 !gensec_security_ops_enabled(all_ops[i], gensec_security))
 158                     continue;
 159
 160                 if (!all_ops[i]->oid) {
 161                         continue;
 162                 }
 163
 164                 is_spnego = false;
 165                 for (j=0; all_ops[i]->oid[j]; j++) {
 166                         if (strcasecmp(GENSEC_OID_SPNEGO,all_ops[i]->oid[j]) == 0) {
 167                                 is_spnego = true;
 168                         }
 169                 }
 170                 if (is_spnego) {
 171                         continue;
 172                 }
 173
 174                 if (!all_ops[i]->magic) {
 175                         continue;
 176                 }
 177
 178                 nt_status = all_ops[i]->magic(gensec_security, &in);
 179                 if (!NT_STATUS_IS_OK(nt_status)) {
 180                         continue;
 181                 }
 182
 183                 spnego_state->state_position = SPNEGO_FALLBACK;
 184
 185                 nt_status = gensec_subcontext_start(spnego_state,
 186                                                     gensec_security,
 187                                                     &spnego_state->sub_sec_security);
 188
 189                 if (!NT_STATUS_IS_OK(nt_status)) {
 190                         return nt_status;
 191                 }
 192                 /* select the sub context */
 193                 nt_status = gensec_start_mech_by_ops(spnego_state->sub_sec_security,
 194                                                      all_ops[i]);
 195                 if (!NT_STATUS_IS_OK(nt_status)) {
 196                         return nt_status;
 197                 }
 198                 nt_status = gensec_update_ev(spnego_state->sub_sec_security,
 199                                              out_mem_ctx, ev, in, out);
 200                 return nt_status;
 201         }
 202         DEBUG(1, ("Failed to parse SPNEGO request\n"));
 203         return NT_STATUS_INVALID_PARAMETER;
 204 }
 205
 206 /*
 207    Parse the netTokenInit, either from the client, to the server, or
 208    from the server to the client.
 209 */
 210
 211 static NTSTATUS gensec_spnego_parse_negTokenInit(struct gensec_security *gensec_security,
 212                                                  struct spnego_state *spnego_state,
 213                                                  TALLOC_CTX *out_mem_ctx,
 214                                                  struct tevent_context *ev,
 215                                                  const char * const *mechType,
 216                                                  const DATA_BLOB unwrapped_in, DATA_BLOB *unwrapped_out)
 217 {
 218         int i;
 219         NTSTATUS nt_status = NT_STATUS_INVALID_PARAMETER;
 220         bool ok;
 221
 222         const struct gensec_security_ops_wrapper *all_sec
 223                 = gensec_security_by_oid_list(gensec_security,
 224                                               out_mem_ctx,
 225                                               mechType,
 226                                               GENSEC_OID_SPNEGO);
 227
 228         ok = spnego_write_mech_types(spnego_state,
 229                                      mechType,
 230                                      &spnego_state->mech_types);
 231         if (!ok) {
 232                 DEBUG(1, ("SPNEGO: Failed to write mechTypes\n"));
 233                 return NT_STATUS_NO_MEMORY;
 234         }
 235
 236         if (spnego_state->state_position == SPNEGO_SERVER_START) {
 237                 uint32_t j;
 238                 for (j=0; mechType && mechType[j]; j++) {
 239                         for (i=0; all_sec && all_sec[i].op; i++) {
 240                                 if (strcmp(mechType[j], all_sec[i].oid) != 0) {
 241                                         continue;
 242                                 }
 243
 244                                 nt_status = gensec_subcontext_start(spnego_state,
 245                                                                     gensec_security,
 246                                                                     &spnego_state->sub_sec_security);
 247                                 if (!NT_STATUS_IS_OK(nt_status)) {
 248                                         return nt_status;
 249                                 }
 250                                 /* select the sub context */
 251                                 nt_status = gensec_start_mech_by_ops(spnego_state->sub_sec_security,
 252                                                                      all_sec[i].op);
 253                                 if (!NT_STATUS_IS_OK(nt_status)) {
 254                                         /*
 255                                          * Pretend we never started it
 256                                          */
 257                                         gensec_spnego_update_sub_abort(spnego_state);
 258                                         break;
 259                                 }
 260
 261                                 if (j > 0) {
 262                                         /* no optimistic token */
 263                                         spnego_state->neg_oid = all_sec[i].oid;
 264                                         *unwrapped_out = data_blob_null;
 265                                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 266                                         /*
 267                                          * Indicate the downgrade and request a
 268                                          * mic.
 269                                          */
 270                                         spnego_state->downgraded = true;
 271                                         spnego_state->mic_requested = true;
 272                                         break;
 273                                 }
 274
 275                                 nt_status = gensec_update_ev(spnego_state->sub_sec_security,
 276                                                           out_mem_ctx,
 277                                                           ev,
 278                                                           unwrapped_in,
 279                                                           unwrapped_out);
 280                                 if (NT_STATUS_IS_OK(nt_status)) {
 281                                         spnego_state->sub_sec_ready = true;
 282                                 }
 283                                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_PARAMETER) ||
 284                                     NT_STATUS_EQUAL(nt_status, NT_STATUS_CANT_ACCESS_DOMAIN_INFO)) {
 285
 286                                         DEBUG(1, ("SPNEGO(%s) NEG_TOKEN_INIT failed to parse contents: %s\n",
 287                                                   spnego_state->sub_sec_security->ops->name, nt_errstr(nt_status)));
 288
 289                                         /*
 290                                          * Pretend we never started it
 291                                          */
 292                                         gensec_spnego_update_sub_abort(spnego_state);
 293                                         break;
 294                                 }
 295
 296                                 spnego_state->neg_oid = all_sec[i].oid;
 297                                 break;
 298                         }
 299                         if (spnego_state->sub_sec_security) {
 300                                 break;
 301                         }
 302                 }
 303
 304                 if (!spnego_state->sub_sec_security) {
 305                         DEBUG(1, ("SPNEGO: Could not find a suitable mechtype in NEG_TOKEN_INIT\n"));
 306                         return NT_STATUS_INVALID_PARAMETER;
 307                 }
 308         }
 309
 310         /* Having tried any optimistic token from the client (if we
 311          * were the server), if we didn't get anywhere, walk our list
 312          * in our preference order */
 313
 314         if (!spnego_state->sub_sec_security) {
 315                 for (i=0; all_sec && all_sec[i].op; i++) {
 316                         nt_status = gensec_subcontext_start(spnego_state,
 317                                                             gensec_security,
 318                                                             &spnego_state->sub_sec_security);
 319                         if (!NT_STATUS_IS_OK(nt_status)) {
 320                                 return nt_status;
 321                         }
 322                         /* select the sub context */
 323                         nt_status = gensec_start_mech_by_ops(spnego_state->sub_sec_security,
 324                                                              all_sec[i].op);
 325                         if (!NT_STATUS_IS_OK(nt_status)) {
 326                                 /*
 327                                  * Pretend we never started it.
 328                                  */
 329                                 gensec_spnego_update_sub_abort(spnego_state);
 330                                 continue;
 331                         }
 332
 333                         spnego_state->neg_oid = all_sec[i].oid;
 334
 335                         /* only get the helping start blob for the first OID */
 336                         nt_status = gensec_update_ev(spnego_state->sub_sec_security,
 337                                                   out_mem_ctx,
 338                                                   ev,
 339                                                   data_blob_null,
 340                                                   unwrapped_out);
 341                         if (NT_STATUS_IS_OK(nt_status)) {
 342                                 spnego_state->sub_sec_ready = true;
 343                         }
 344
 345                         /* it is likely that a NULL input token will
 346                          * not be liked by most server mechs, but if
 347                          * we are in the client, we want the first
 348                          * update packet to be able to abort the use
 349                          * of this mech */
 350                         if (spnego_state->state_position != SPNEGO_SERVER_START) {
 351                                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_PARAMETER) ||
 352                                     NT_STATUS_EQUAL(nt_status, NT_STATUS_NO_LOGON_SERVERS) ||
 353                                     NT_STATUS_EQUAL(nt_status, NT_STATUS_TIME_DIFFERENCE_AT_DC) ||
 354                                     NT_STATUS_EQUAL(nt_status, NT_STATUS_CANT_ACCESS_DOMAIN_INFO)) {
 355                                         const char *next = NULL;
 356                                         const char *principal = NULL;
 357                                         int dbg_level = DBGLVL_WARNING;
 358
 359                                         if (all_sec[i+1].op != NULL) {
 360                                                 next = all_sec[i+1].op->name;
 361                                                 dbg_level = DBGLVL_NOTICE;
 362                                         }
 363
 364                                         if (gensec_security->target.principal != NULL) {
 365                                                 principal = gensec_security->target.principal;
 366                                         } else if (gensec_security->target.service != NULL &&
 367                                                    gensec_security->target.hostname != NULL)
 368                                         {
 369                                                 principal = talloc_asprintf(spnego_state->sub_sec_security,
 370                                                                             "%s/%s",
 371                                                                             gensec_security->target.service,
 372                                                                             gensec_security->target.hostname);
 373                                         } else {
 374                                                 principal = gensec_security->target.hostname;
 375                                         }
 376
 377                                         DEBUG(dbg_level, ("SPNEGO(%s) creating NEG_TOKEN_INIT for %s failed (next[%s]): %s\n",
 378                                                           spnego_state->sub_sec_security->ops->name,
 379                                                           principal,
 380                                                           next, nt_errstr(nt_status)));
 381
 382                                         /*
 383                                          * Pretend we never started it.
 384                                          */
 385                                         gensec_spnego_update_sub_abort(spnego_state);
 386                                         continue;
 387                                 }
 388                         }
 389
 390                         break;
 391                 }
 392         }
 393
 394         if (spnego_state->sub_sec_security) {
 395                 /* it is likely that a NULL input token will
 396                  * not be liked by most server mechs, but this
 397                  * does the right thing in the CIFS client.
 398                  * just push us along the merry-go-round
 399                  * again, and hope for better luck next
 400                  * time */
 401
 402                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_PARAMETER)) {
 403                         *unwrapped_out = data_blob_null;
 404                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 405                 }
 406
 407                 if (!NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_PARAMETER)
 408                     && !NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)
 409                     && !NT_STATUS_IS_OK(nt_status)) {
 410                         DEBUG(1, ("SPNEGO(%s) NEG_TOKEN_INIT failed: %s\n",
 411                                   spnego_state->sub_sec_security->ops->name, nt_errstr(nt_status)));
 412
 413                         /* We started the mech correctly, and the
 414                          * input from the other side was valid.
 415                          * Return the error (say bad password, invalid
 416                          * ticket) */
 417                         gensec_spnego_update_sub_abort(spnego_state);
 418                         return nt_status;
 419                 }
 420
 421                 return nt_status; /* OK, INVALID_PARAMETER ore MORE PROCESSING */
 422         }
 423
 424         DEBUG(1, ("SPNEGO: Could not find a suitable mechtype in NEG_TOKEN_INIT\n"));
 425         /* we could re-negotiate here, but it would only work
 426          * if the client or server lied about what it could
 427          * support the first time.  Lets keep this code to
 428          * reality */
 429
 430         return nt_status;
 431 }
 432
 433 /** create a negTokenInit
 434  *
 435  * This is the same packet, no matter if the client or server sends it first, but it is always the first packet
 436 */
 437 static NTSTATUS gensec_spnego_create_negTokenInit(struct gensec_security *gensec_security,
 438                                                   struct spnego_state *spnego_state,
 439                                                   TALLOC_CTX *out_mem_ctx,
 440                                                   struct tevent_context *ev,
 441                                                   DATA_BLOB *out)
 442 {
 443         int i;
 444         NTSTATUS nt_status = NT_STATUS_INVALID_PARAMETER;
 445         const char **mechTypes = NULL;
 446         DATA_BLOB unwrapped_out = data_blob_null;
 447         const struct gensec_security_ops_wrapper *all_sec;
 448
 449         mechTypes = gensec_security_oids(gensec_security,
 450                                          out_mem_ctx, GENSEC_OID_SPNEGO);
 451
 452         all_sec = gensec_security_by_oid_list(gensec_security,
 453                                               out_mem_ctx,
 454                                               mechTypes,
 455                                               GENSEC_OID_SPNEGO);
 456         for (i=0; all_sec && all_sec[i].op; i++) {
 457                 struct spnego_data spnego_out;
 458                 const char **send_mech_types;
 459                 bool ok;
 460
 461                 nt_status = gensec_subcontext_start(spnego_state,
 462                                                     gensec_security,
 463                                                     &spnego_state->sub_sec_security);
 464                 if (!NT_STATUS_IS_OK(nt_status)) {
 465                         return nt_status;
 466                 }
 467                 /* select the sub context */
 468                 nt_status = gensec_start_mech_by_ops(spnego_state->sub_sec_security,
 469                                                      all_sec[i].op);
 470                 if (!NT_STATUS_IS_OK(nt_status)) {
 471                         gensec_spnego_update_sub_abort(spnego_state);
 472                         continue;
 473                 }
 474
 475                 /* In the client, try and produce the first (optimistic) packet */
 476                 if (spnego_state->state_position == SPNEGO_CLIENT_START) {
 477                         nt_status = gensec_update_ev(spnego_state->sub_sec_security,
 478                                                   out_mem_ctx,
 479                                                   ev,
 480                                                   data_blob_null,
 481                                                   &unwrapped_out);
 482                         if (NT_STATUS_IS_OK(nt_status)) {
 483                                 spnego_state->sub_sec_ready = true;
 484                         }
 485
 486                         if (!NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)
 487                             && !NT_STATUS_IS_OK(nt_status)) {
 488                                 const char *next = NULL;
 489                                 const char *principal = NULL;
 490                                 int dbg_level = DBGLVL_WARNING;
 491
 492                                 if (all_sec[i+1].op != NULL) {
 493                                         next = all_sec[i+1].op->name;
 494                                         dbg_level = DBGLVL_NOTICE;
 495                                 }
 496
 497                                 if (gensec_security->target.principal != NULL) {
 498                                         principal = gensec_security->target.principal;
 499                                 } else if (gensec_security->target.service != NULL &&
 500                                            gensec_security->target.hostname != NULL)
 501                                 {
 502                                         principal = talloc_asprintf(spnego_state->sub_sec_security,
 503                                                                     "%s/%s",
 504                                                                     gensec_security->target.service,
 505                                                                     gensec_security->target.hostname);
 506                                 } else {
 507                                         principal = gensec_security->target.hostname;
 508                                 }
 509
 510                                 DEBUG(dbg_level, ("SPNEGO(%s) creating NEG_TOKEN_INIT for %s failed (next[%s]): %s\n",
 511                                           spnego_state->sub_sec_security->ops->name,
 512                                           principal,
 513                                           next, nt_errstr(nt_status)));
 514
 515                                 /*
 516                                  * Pretend we never started it
 517                                  */
 518                                 gensec_spnego_update_sub_abort(spnego_state);
 519                                 continue;
 520                         }
 521                 }
 522
 523                 spnego_out.type = SPNEGO_NEG_TOKEN_INIT;
 524
 525                 send_mech_types = gensec_security_oids_from_ops_wrapped(out_mem_ctx,
 526                                                                         &all_sec[i]);
 527
 528                 ok = spnego_write_mech_types(spnego_state,
 529                                              send_mech_types,
 530                                              &spnego_state->mech_types);
 531                 if (!ok) {
 532                         DEBUG(1, ("SPNEGO: Failed to write mechTypes\n"));
 533                         return NT_STATUS_NO_MEMORY;
 534                 }
 535
 536                 /* List the remaining mechs as options */
 537                 spnego_out.negTokenInit.mechTypes = send_mech_types;
 538                 spnego_out.negTokenInit.reqFlags = data_blob_null;
 539                 spnego_out.negTokenInit.reqFlagsPadding = 0;
 540
 541                 if (spnego_state->state_position == SPNEGO_SERVER_START) {
 542                         spnego_out.negTokenInit.mechListMIC
 543                                 = data_blob_string_const(ADS_IGNORE_PRINCIPAL);
 544                 } else {
 545                         spnego_out.negTokenInit.mechListMIC = data_blob_null;
 546                 }
 547
 548                 spnego_out.negTokenInit.mechToken = unwrapped_out;
 549
 550                 if (spnego_write_data(out_mem_ctx, out, &spnego_out) == -1) {
 551                         DEBUG(1, ("Failed to write NEG_TOKEN_INIT\n"));
 552                                 return NT_STATUS_INVALID_PARAMETER;
 553                 }
 554
 555                 /* set next state */
 556                 spnego_state->neg_oid = all_sec[i].oid;
 557
 558                 if (spnego_state->state_position == SPNEGO_SERVER_START) {
 559                         spnego_state->state_position = SPNEGO_SERVER_START;
 560                         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_INIT;
 561                 } else {
 562                         spnego_state->state_position = SPNEGO_CLIENT_TARG;
 563                         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_TARG;
 564                 }
 565
 566                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 567         }
 568         gensec_spnego_update_sub_abort(spnego_state);
 569
 570         DEBUG(10, ("Failed to setup SPNEGO negTokenInit request: %s\n", nt_errstr(nt_status)));
 571         return nt_status;
 572 }
 573
 574
 575 /** create a server negTokenTarg
 576  *
 577  * This is the case, where the client is the first one who sends data
 578 */
 579
 580 static NTSTATUS gensec_spnego_server_response(struct spnego_state *spnego_state,
 581                                               TALLOC_CTX *out_mem_ctx,
 582                                               NTSTATUS nt_status,
 583                                               const DATA_BLOB unwrapped_out,
 584                                               DATA_BLOB mech_list_mic,
 585                                               DATA_BLOB *out)
 586 {
 587         struct spnego_data spnego_out;
 588
 589         /* compose reply */
 590         spnego_out.type = SPNEGO_NEG_TOKEN_TARG;
 591         spnego_out.negTokenTarg.responseToken = unwrapped_out;
 592         spnego_out.negTokenTarg.mechListMIC = mech_list_mic;
 593         spnego_out.negTokenTarg.supportedMech = NULL;
 594
 595         if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 596                 spnego_out.negTokenTarg.supportedMech = spnego_state->neg_oid;
 597                 if (spnego_state->mic_requested) {
 598                         spnego_out.negTokenTarg.negResult = SPNEGO_REQUEST_MIC;
 599                         spnego_state->mic_requested = false;
 600                 } else {
 601                         spnego_out.negTokenTarg.negResult = SPNEGO_ACCEPT_INCOMPLETE;
 602                 }
 603                 spnego_state->state_position = SPNEGO_SERVER_TARG;
 604         } else if (NT_STATUS_IS_OK(nt_status)) {
 605                 if (unwrapped_out.data) {
 606                         spnego_out.negTokenTarg.supportedMech = spnego_state->neg_oid;
 607                 }
 608                 spnego_out.negTokenTarg.negResult = SPNEGO_ACCEPT_COMPLETED;
 609                 spnego_state->state_position = SPNEGO_DONE;
 610         } else {
 611                 spnego_out.negTokenTarg.negResult = SPNEGO_REJECT;
 612                 spnego_out.negTokenTarg.mechListMIC = data_blob_null;
 613                 DEBUG(2, ("SPNEGO login failed: %s\n", nt_errstr(nt_status)));
 614                 spnego_state->state_position = SPNEGO_DONE;
 615         }
 616
 617         if (spnego_write_data(out_mem_ctx, out, &spnego_out) == -1) {
 618                 DEBUG(1, ("Failed to write SPNEGO reply to NEG_TOKEN_TARG\n"));
 619                 return NT_STATUS_INVALID_PARAMETER;
 620         }
 621
 622         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_TARG;
 623         spnego_state->num_targs++;
 624
 625         return nt_status;
 626 }
 627
 628 static NTSTATUS gensec_spnego_update_client(struct gensec_security *gensec_security,
 629                                             TALLOC_CTX *out_mem_ctx,
 630                                             struct tevent_context *ev,
 631                                             const DATA_BLOB in, DATA_BLOB *out)
 632 {
 633         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 634         DATA_BLOB mech_list_mic = data_blob_null;
 635         DATA_BLOB unwrapped_out = data_blob_null;
 636         struct spnego_data spnego_out;
 637         struct spnego_data spnego;
 638         ssize_t len;
 639
 640         *out = data_blob_null;
 641
 642         /* and switch into the state machine */
 643
 644         switch (spnego_state->state_position) {
 645         case SPNEGO_CLIENT_START:
 646         {
 647                 /* The server offers a list of mechanisms */
 648
 649                 const char *my_mechs[] = {NULL, NULL};
 650                 NTSTATUS nt_status = NT_STATUS_INVALID_PARAMETER;
 651                 bool ok;
 652                 const char *tp = NULL;
 653
 654                 if (!in.length) {
 655                         /* client to produce negTokenInit */
 656                         return gensec_spnego_create_negTokenInit(gensec_security,
 657                                                                  spnego_state,
 658                                                                  out_mem_ctx,
 659                                                                  ev, out);
 660                 }
 661
 662                 len = spnego_read_data(gensec_security, in, &spnego);
 663
 664                 if (len == -1) {
 665                         DEBUG(1, ("Invalid SPNEGO request:\n"));
 666                         dump_data(1, in.data, in.length);
 667                         return NT_STATUS_INVALID_PARAMETER;
 668                 }
 669
 670                 /* OK, so it's real SPNEGO, check the packet's the one we expect */
 671                 if (spnego.type != spnego_state->expected_packet) {
 672                         DEBUG(1, ("Invalid SPNEGO request: %d, expected %d\n", spnego.type,
 673                                   spnego_state->expected_packet));
 674                         dump_data(1, in.data, in.length);
 675                         spnego_free_data(&spnego);
 676                         return NT_STATUS_INVALID_PARAMETER;
 677                 }
 678
 679                 tp = spnego.negTokenInit.targetPrincipal;
 680                 if (tp != NULL && strcmp(tp, ADS_IGNORE_PRINCIPAL) != 0) {
 681                         DEBUG(5, ("Server claims it's principal name is %s\n", tp));
 682                         if (lpcfg_client_use_spnego_principal(gensec_security->settings->lp_ctx)) {
 683                                 gensec_set_target_principal(gensec_security, tp);
 684                         }
 685                 }
 686
 687                 nt_status = gensec_spnego_parse_negTokenInit(gensec_security,
 688                                                              spnego_state,
 689                                                              out_mem_ctx,
 690                                                              ev,
 691                                                              spnego.negTokenInit.mechTypes,
 692                                                              spnego.negTokenInit.mechToken,
 693                                                              &unwrapped_out);
 694
 695                 if (!NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED) && !NT_STATUS_IS_OK(nt_status)) {
 696                         spnego_free_data(&spnego);
 697                         return nt_status;
 698                 }
 699
 700                 my_mechs[0] = spnego_state->neg_oid;
 701                 /* compose reply */
 702                 spnego_out.type = SPNEGO_NEG_TOKEN_INIT;
 703                 spnego_out.negTokenInit.mechTypes = my_mechs;
 704                 spnego_out.negTokenInit.reqFlags = data_blob_null;
 705                 spnego_out.negTokenInit.reqFlagsPadding = 0;
 706                 spnego_out.negTokenInit.mechListMIC = data_blob_null;
 707                 spnego_out.negTokenInit.mechToken = unwrapped_out;
 708
 709                 if (spnego_write_data(out_mem_ctx, out, &spnego_out) == -1) {
 710                         DEBUG(1, ("Failed to write SPNEGO reply to NEG_TOKEN_INIT\n"));
 711                                 return NT_STATUS_INVALID_PARAMETER;
 712                 }
 713
 714                 ok = spnego_write_mech_types(spnego_state,
 715                                              my_mechs,
 716                                              &spnego_state->mech_types);
 717                 if (!ok) {
 718                         DEBUG(1, ("SPNEGO: Failed to write mechTypes\n"));
 719                         return NT_STATUS_NO_MEMORY;
 720                 }
 721
 722                 /* set next state */
 723                 spnego_state->expected_packet = SPNEGO_NEG_TOKEN_TARG;
 724                 spnego_state->state_position = SPNEGO_CLIENT_TARG;
 725
 726                 spnego_free_data(&spnego);
 727                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 728         }
 729
 730         case SPNEGO_CLIENT_TARG:
 731         {
 732                 NTSTATUS nt_status = NT_STATUS_INTERNAL_ERROR;
 733                 const struct spnego_negTokenTarg *ta = NULL;
 734
 735                 if (!in.length) {
 736                         return NT_STATUS_INVALID_PARAMETER;
 737                 }
 738
 739                 len = spnego_read_data(gensec_security, in, &spnego);
 740
 741                 if (len == -1) {
 742                         DEBUG(1, ("Invalid SPNEGO request:\n"));
 743                         dump_data(1, in.data, in.length);
 744                         return NT_STATUS_INVALID_PARAMETER;
 745                 }
 746
 747                 /* OK, so it's real SPNEGO, check the packet's the one we expect */
 748                 if (spnego.type != spnego_state->expected_packet) {
 749                         DEBUG(1, ("Invalid SPNEGO request: %d, expected %d\n", spnego.type,
 750                                   spnego_state->expected_packet));
 751                         dump_data(1, in.data, in.length);
 752                         spnego_free_data(&spnego);
 753                         return NT_STATUS_INVALID_PARAMETER;
 754                 }
 755                 ta = &spnego.negTokenTarg;
 756
 757                 spnego_state->num_targs++;
 758
 759                 if (ta->negResult == SPNEGO_REJECT) {
 760                         return NT_STATUS_LOGON_FAILURE;
 761                 }
 762
 763                 if (spnego.negTokenTarg.negResult == SPNEGO_REQUEST_MIC) {
 764                         spnego_state->mic_requested = true;
 765                 }
 766
 767                 /* Server didn't like our choice of mech, and chose something else */
 768                 if (((ta->negResult == SPNEGO_ACCEPT_INCOMPLETE) ||
 769                      (ta->negResult == SPNEGO_REQUEST_MIC)) &&
 770                     ta->supportedMech != NULL&&
 771                     strcmp(ta->supportedMech, spnego_state->neg_oid) != 0) {
 772                         DEBUG(3,("GENSEC SPNEGO: client preferred mech (%s) not accepted, server wants: %s\n",
 773                                  gensec_get_name_by_oid(gensec_security, spnego_state->neg_oid),
 774                                  gensec_get_name_by_oid(gensec_security, ta->supportedMech)));
 775                         spnego_state->downgraded = true;
 776                         gensec_spnego_update_sub_abort(spnego_state);
 777                         nt_status = gensec_subcontext_start(spnego_state,
 778                                                             gensec_security,
 779                                                             &spnego_state->sub_sec_security);
 780                         if (!NT_STATUS_IS_OK(nt_status)) {
 781                                 spnego_free_data(&spnego);
 782                                 return nt_status;
 783                         }
 784                         /* select the sub context */
 785                         nt_status = gensec_start_mech_by_oid(spnego_state->sub_sec_security,
 786                                                              ta->supportedMech);
 787                         if (!NT_STATUS_IS_OK(nt_status)) {
 788                                 spnego_free_data(&spnego);
 789                                 return nt_status;
 790                         }
 791
 792                         spnego_state->neg_oid = talloc_strdup(spnego_state,
 793                                                 ta->supportedMech);
 794                         if (spnego_state->neg_oid == NULL) {
 795                                 spnego_free_data(&spnego);
 796                                 return NT_STATUS_NO_MEMORY;
 797                         };
 798                 }
 799
 800                 if (spnego.negTokenTarg.mechListMIC.length > 0) {
 801                         DATA_BLOB *m = &spnego.negTokenTarg.mechListMIC;
 802                         const DATA_BLOB *r = &spnego.negTokenTarg.responseToken;
 803
 804                         /*
 805                          * Windows 2000 has a bug, it repeats the
 806                          * responseToken in the mechListMIC field.
 807                          */
 808                         if (m->length == r->length) {
 809                                 int cmp;
 810
 811                                 cmp = memcmp(m->data, r->data, m->length);
 812                                 if (cmp == 0) {
 813                                         data_blob_free(m);
 814                                 }
 815                         }
 816                 }
 817
 818                 if (spnego.negTokenTarg.mechListMIC.length > 0) {
 819                         if (spnego_state->sub_sec_ready) {
 820                                 spnego_state->needs_mic_check = true;
 821                         }
 822                 }
 823
 824                 if (spnego_state->needs_mic_check) {
 825                         if (spnego.negTokenTarg.responseToken.length != 0) {
 826                                 DEBUG(1, ("SPNEGO: Did not setup a mech in NEG_TOKEN_INIT\n"));
 827                                 spnego_free_data(&spnego);
 828                                 return NT_STATUS_INVALID_PARAMETER;
 829                         }
 830
 831                         if (spnego.negTokenTarg.mechListMIC.length == 0
 832                             && spnego_state->may_skip_mic_check) {
 833                                 /*
 834                                  * In this case we don't require
 835                                  * a mechListMIC from the server.
 836                                  *
 837                                  * This works around bugs in the Azure
 838                                  * and Apple spnego implementations.
 839                                  *
 840                                  * See
 841                                  * https://bugzilla.samba.org/show_bug.cgi?id=11994
 842                                  */
 843                                 spnego_state->needs_mic_check = false;
 844                                 nt_status = NT_STATUS_OK;
 845                                 goto client_response;
 846                         }
 847
 848                         nt_status = gensec_check_packet(spnego_state->sub_sec_security,
 849                                                         spnego_state->mech_types.data,
 850                                                         spnego_state->mech_types.length,
 851                                                         spnego_state->mech_types.data,
 852                                                         spnego_state->mech_types.length,
 853                                                         &spnego.negTokenTarg.mechListMIC);
 854                         if (!NT_STATUS_IS_OK(nt_status)) {
 855                                 DEBUG(2,("GENSEC SPNEGO: failed to verify mechListMIC: %s\n",
 856                                         nt_errstr(nt_status)));
 857                                 spnego_free_data(&spnego);
 858                                 return nt_status;
 859                         }
 860                         spnego_state->needs_mic_check = false;
 861                         spnego_state->done_mic_check = true;
 862                         goto client_response;
 863                 }
 864
 865                 if (!spnego_state->sub_sec_ready) {
 866                         nt_status = gensec_update_ev(spnego_state->sub_sec_security,
 867                                                   out_mem_ctx, ev,
 868                                                   spnego.negTokenTarg.responseToken,
 869                                                   &unwrapped_out);
 870                         if (NT_STATUS_IS_OK(nt_status)) {
 871                                 spnego_state->sub_sec_ready = true;
 872                         }
 873                         if (!NT_STATUS_IS_OK(nt_status)) {
 874                                 goto client_response;
 875                         }
 876                 } else {
 877                         nt_status = NT_STATUS_OK;
 878                 }
 879
 880                 if (!spnego_state->done_mic_check) {
 881                         bool have_sign = true;
 882                         bool new_spnego = false;
 883
 884                         have_sign = gensec_have_feature(spnego_state->sub_sec_security,
 885                                                         GENSEC_FEATURE_SIGN);
 886                         if (spnego_state->simulate_w2k) {
 887                                 have_sign = false;
 888                         }
 889                         new_spnego = gensec_have_feature(spnego_state->sub_sec_security,
 890                                                          GENSEC_FEATURE_NEW_SPNEGO);
 891
 892                         switch (spnego.negTokenTarg.negResult) {
 893                         case SPNEGO_ACCEPT_COMPLETED:
 894                         case SPNEGO_NONE_RESULT:
 895                                 if (spnego_state->num_targs == 1) {
 896                                         /*
 897                                          * the first exchange doesn't require
 898                                          * verification
 899                                          */
 900                                         new_spnego = false;
 901                                 }
 902
 903                                 break;
 904
 905                         case SPNEGO_ACCEPT_INCOMPLETE:
 906                                 if (spnego.negTokenTarg.mechListMIC.length > 0) {
 907                                         new_spnego = true;
 908                                         break;
 909                                 }
 910
 911                                 if (spnego_state->downgraded) {
 912                                         /*
 913                                          * A downgrade should be protected if
 914                                          * supported
 915                                          */
 916                                         break;
 917                                 }
 918
 919                                 /*
 920                                  * The caller may just asked for
 921                                  * GENSEC_FEATURE_SESSION_KEY, this
 922                                  * is only reflected in the want_features.
 923                                  *
 924                                  * As it will imply
 925                                  * gensec_have_features(GENSEC_FEATURE_SIGN)
 926                                  * to return true.
 927                                  */
 928                                 if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 929                                         break;
 930                                 }
 931                                 if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 932                                         break;
 933                                 }
 934                                 /*
 935                                  * Here we're sure our preferred mech was
 936                                  * selected by the server and our caller doesn't
 937                                  * need GENSEC_FEATURE_SIGN nor
 938                                  * GENSEC_FEATURE_SEAL support.
 939                                  *
 940                                  * In this case we don't require
 941                                  * a mechListMIC from the server.
 942                                  *
 943                                  * This works around bugs in the Azure
 944                                  * and Apple spnego implementations.
 945                                  *
 946                                  * See
 947                                  * https://bugzilla.samba.org/show_bug.cgi?id=11994
 948                                  */
 949                                 spnego_state->may_skip_mic_check = true;
 950                                 break;
 951
 952                         case SPNEGO_REQUEST_MIC:
 953                                 if (spnego.negTokenTarg.mechListMIC.length > 0) {
 954                                         new_spnego = true;
 955                                 }
 956                                 break;
 957                         default:
 958                                 break;
 959                         }
 960
 961                         if (spnego_state->mic_requested) {
 962                                 if (have_sign) {
 963                                         new_spnego = true;
 964                                 }
 965                         }
 966
 967                         if (have_sign && new_spnego) {
 968                                 spnego_state->needs_mic_check = true;
 969                                 spnego_state->needs_mic_sign = true;
 970                         }
 971                 }
 972
 973                 if (spnego.negTokenTarg.mechListMIC.length > 0) {
 974                         nt_status = gensec_check_packet(spnego_state->sub_sec_security,
 975                                                         spnego_state->mech_types.data,
 976                                                         spnego_state->mech_types.length,
 977                                                         spnego_state->mech_types.data,
 978                                                         spnego_state->mech_types.length,
 979                                                         &spnego.negTokenTarg.mechListMIC);
 980                         if (!NT_STATUS_IS_OK(nt_status)) {
 981                                 DEBUG(2,("GENSEC SPNEGO: failed to verify mechListMIC: %s\n",
 982                                         nt_errstr(nt_status)));
 983                                 spnego_free_data(&spnego);
 984                                 return nt_status;
 985                         }
 986                         spnego_state->needs_mic_check = false;
 987                         spnego_state->done_mic_check = true;
 988                 }
 989
 990                 if (spnego_state->needs_mic_sign) {
 991                         nt_status = gensec_sign_packet(spnego_state->sub_sec_security,
 992                                                        out_mem_ctx,
 993                                                        spnego_state->mech_types.data,
 994                                                        spnego_state->mech_types.length,
 995                                                        spnego_state->mech_types.data,
 996                                                        spnego_state->mech_types.length,
 997                                                        &mech_list_mic);
 998                         if (!NT_STATUS_IS_OK(nt_status)) {
 999                                 DEBUG(2,("GENSEC SPNEGO: failed to sign mechListMIC: %s\n",
1000                                         nt_errstr(nt_status)));
1001                                 spnego_free_data(&spnego);
1002                                 return nt_status;
1003                         }
1004                         spnego_state->needs_mic_sign = false;
1005                 }
1006
1007                 if (spnego_state->needs_mic_check) {
1008                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
1009                 }
1010
1011  client_response:
1012                 spnego_free_data(&spnego);
1013
1014                 if (!NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)
1015                         && !NT_STATUS_IS_OK(nt_status)) {
1016                         DEBUG(1, ("SPNEGO(%s) login failed: %s\n",
1017                                   spnego_state->sub_sec_security->ops->name,
1018                                   nt_errstr(nt_status)));
1019                         return nt_status;
1020                 }
1021
1022                 if (unwrapped_out.length || mech_list_mic.length) {
1023                         /* compose reply */
1024                         spnego_out.type = SPNEGO_NEG_TOKEN_TARG;
1025                         spnego_out.negTokenTarg.negResult = SPNEGO_NONE_RESULT;
1026                         spnego_out.negTokenTarg.supportedMech = NULL;
1027                         spnego_out.negTokenTarg.responseToken = unwrapped_out;
1028                         spnego_out.negTokenTarg.mechListMIC = mech_list_mic;
1029
1030                         if (spnego_write_data(out_mem_ctx, out, &spnego_out) == -1) {
1031                                 DEBUG(1, ("Failed to write SPNEGO reply to NEG_TOKEN_TARG\n"));
1032                                 return NT_STATUS_INVALID_PARAMETER;
1033                         }
1034
1035                         spnego_state->num_targs++;
1036                         spnego_state->state_position = SPNEGO_CLIENT_TARG;
1037                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
1038                 } else {
1039
1040                         /* all done - server has accepted, and we agree */
1041                         *out = data_blob_null;
1042
1043                         if (ta->negResult != SPNEGO_ACCEPT_COMPLETED) {
1044                                 /* unless of course it did not accept */
1045                                 DEBUG(1,("gensec_update ok but not accepted\n"));
1046                                 nt_status = NT_STATUS_INVALID_PARAMETER;
1047                         }
1048
1049                         spnego_state->state_position = SPNEGO_DONE;
1050                 }
1051
1052                 return nt_status;
1053         }
1054
1055         default:
1056                 break;
1057         }
1058
1059         smb_panic(__location__);
1060         return NT_STATUS_INTERNAL_ERROR;
1061 }
1062
1063 static NTSTATUS gensec_spnego_update_server(struct gensec_security *gensec_security,
1064                                             TALLOC_CTX *out_mem_ctx,
1065                                             struct tevent_context *ev,
1066                                             const DATA_BLOB in, DATA_BLOB *out)
1067 {
1068         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
1069         DATA_BLOB mech_list_mic = data_blob_null;
1070         DATA_BLOB unwrapped_out = data_blob_null;
1071         struct spnego_data spnego;
1072         ssize_t len;
1073
1074         /* and switch into the state machine */
1075
1076         switch (spnego_state->state_position) {
1077         case SPNEGO_SERVER_START:
1078         {
1079                 NTSTATUS nt_status;
1080
1081                 if (in.length == 0) {
1082                         return gensec_spnego_create_negTokenInit(gensec_security,
1083                                                                  spnego_state,
1084                                                                  out_mem_ctx,
1085                                                                  ev, out);
1086                 }
1087
1088                 len = spnego_read_data(gensec_security, in, &spnego);
1089                 if (len == -1) {
1090                         return gensec_spnego_server_try_fallback(gensec_security, spnego_state,
1091                                                                  ev, out_mem_ctx, in, out);
1092                 }
1093                 /* client sent NegTargetInit, we send NegTokenTarg */
1094
1095                 /* OK, so it's real SPNEGO, check the packet's the one we expect */
1096                 if (spnego.type != spnego_state->expected_packet) {
1097                         DEBUG(1, ("Invalid SPNEGO request: %d, expected %d\n", spnego.type,
1098                                   spnego_state->expected_packet));
1099                         dump_data(1, in.data, in.length);
1100                         spnego_free_data(&spnego);
1101                         return NT_STATUS_INVALID_PARAMETER;
1102                 }
1103
1104                 nt_status = gensec_spnego_parse_negTokenInit(gensec_security,
1105                                                              spnego_state,
1106                                                              out_mem_ctx,
1107                                                              ev,
1108                                                              spnego.negTokenInit.mechTypes,
1109                                                              spnego.negTokenInit.mechToken,
1110                                                              &unwrapped_out);
1111
1112                 if (spnego_state->simulate_w2k) {
1113                         /*
1114                          * Windows 2000 returns the unwrapped token
1115                          * also in the mech_list_mic field.
1116                          *
1117                          * In order to verify our client code,
1118                          * we need a way to have a server with this
1119                          * broken behaviour
1120                          */
1121                         mech_list_mic = unwrapped_out;
1122                 }
1123
1124                 nt_status = gensec_spnego_server_response(spnego_state,
1125                                                           out_mem_ctx,
1126                                                           nt_status,
1127                                                           unwrapped_out,
1128                                                           mech_list_mic,
1129                                                           out);
1130
1131                 spnego_free_data(&spnego);
1132
1133                 return nt_status;
1134         }
1135
1136         case SPNEGO_SERVER_TARG:
1137         {
1138                 NTSTATUS nt_status;
1139                 bool have_sign = true;
1140                 bool new_spnego = false;
1141
1142                 if (!in.length) {
1143                         return NT_STATUS_INVALID_PARAMETER;
1144                 }
1145
1146                 len = spnego_read_data(gensec_security, in, &spnego);
1147
1148                 if (len == -1) {
1149                         DEBUG(1, ("Invalid SPNEGO request:\n"));
1150                         dump_data(1, in.data, in.length);
1151                         return NT_STATUS_INVALID_PARAMETER;
1152                 }
1153
1154                 /* OK, so it's real SPNEGO, check the packet's the one we expect */
1155                 if (spnego.type != spnego_state->expected_packet) {
1156                         DEBUG(1, ("Invalid SPNEGO request: %d, expected %d\n", spnego.type,
1157                                   spnego_state->expected_packet));
1158                         dump_data(1, in.data, in.length);
1159                         spnego_free_data(&spnego);
1160                         return NT_STATUS_INVALID_PARAMETER;
1161                 }
1162
1163                 spnego_state->num_targs++;
1164
1165                 if (!spnego_state->sub_sec_security) {
1166                         DEBUG(1, ("SPNEGO: Did not setup a mech in NEG_TOKEN_INIT\n"));
1167                         spnego_free_data(&spnego);
1168                         return NT_STATUS_INVALID_PARAMETER;
1169                 }
1170
1171                 if (spnego_state->needs_mic_check) {
1172                         if (spnego.negTokenTarg.responseToken.length != 0) {
1173                                 DEBUG(1, ("SPNEGO: Did not setup a mech in NEG_TOKEN_INIT\n"));
1174                                 spnego_free_data(&spnego);
1175                                 return NT_STATUS_INVALID_PARAMETER;
1176                         }
1177
1178                         nt_status = gensec_check_packet(spnego_state->sub_sec_security,
1179                                                         spnego_state->mech_types.data,
1180                                                         spnego_state->mech_types.length,
1181                                                         spnego_state->mech_types.data,
1182                                                         spnego_state->mech_types.length,
1183                                                         &spnego.negTokenTarg.mechListMIC);
1184                         if (NT_STATUS_IS_OK(nt_status)) {
1185                                 spnego_state->needs_mic_check = false;
1186                                 spnego_state->done_mic_check = true;
1187                         } else {
1188                                 DEBUG(2,("GENSEC SPNEGO: failed to verify mechListMIC: %s\n",
1189                                         nt_errstr(nt_status)));
1190                         }
1191                         goto server_response;
1192                 }
1193
1194                 nt_status = gensec_update_ev(spnego_state->sub_sec_security,
1195                                              out_mem_ctx, ev,
1196                                              spnego.negTokenTarg.responseToken,
1197                                              &unwrapped_out);
1198                 if (NT_STATUS_IS_OK(nt_status)) {
1199                         spnego_state->sub_sec_ready = true;
1200                 }
1201                 if (!NT_STATUS_IS_OK(nt_status)) {
1202                         goto server_response;
1203                 }
1204
1205                 have_sign = gensec_have_feature(spnego_state->sub_sec_security,
1206                                                 GENSEC_FEATURE_SIGN);
1207                 if (spnego_state->simulate_w2k) {
1208                         have_sign = false;
1209                 }
1210                 new_spnego = gensec_have_feature(spnego_state->sub_sec_security,
1211                                                  GENSEC_FEATURE_NEW_SPNEGO);
1212                 if (spnego.negTokenTarg.mechListMIC.length > 0) {
1213                         new_spnego = true;
1214                 }
1215
1216                 if (have_sign && new_spnego) {
1217                         spnego_state->needs_mic_check = true;
1218                         spnego_state->needs_mic_sign = true;
1219                 }
1220
1221                 if (have_sign && spnego.negTokenTarg.mechListMIC.length > 0) {
1222                         nt_status = gensec_check_packet(spnego_state->sub_sec_security,
1223                                                         spnego_state->mech_types.data,
1224                                                         spnego_state->mech_types.length,
1225                                                         spnego_state->mech_types.data,
1226                                                         spnego_state->mech_types.length,
1227                                                         &spnego.negTokenTarg.mechListMIC);
1228                         if (!NT_STATUS_IS_OK(nt_status)) {
1229                                 DEBUG(2,("GENSEC SPNEGO: failed to verify mechListMIC: %s\n",
1230                                         nt_errstr(nt_status)));
1231                                 goto server_response;
1232                         }
1233
1234                         spnego_state->needs_mic_check = false;
1235                         spnego_state->done_mic_check = true;
1236                 }
1237
1238                 if (spnego_state->needs_mic_sign) {
1239                         nt_status = gensec_sign_packet(spnego_state->sub_sec_security,
1240                                                        out_mem_ctx,
1241                                                        spnego_state->mech_types.data,
1242                                                        spnego_state->mech_types.length,
1243                                                        spnego_state->mech_types.data,
1244                                                        spnego_state->mech_types.length,
1245                                                        &mech_list_mic);
1246                         if (!NT_STATUS_IS_OK(nt_status)) {
1247                                 DEBUG(2,("GENSEC SPNEGO: failed to sign mechListMIC: %s\n",
1248                                         nt_errstr(nt_status)));
1249                                 goto server_response;
1250                         }
1251                         spnego_state->needs_mic_sign = false;
1252                 }
1253
1254                 if (spnego_state->needs_mic_check) {
1255                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
1256                 }
1257
1258  server_response:
1259                 nt_status = gensec_spnego_server_response(spnego_state,
1260                                                           out_mem_ctx,
1261                                                           nt_status,
1262                                                           unwrapped_out,
1263                                                           mech_list_mic,
1264                                                           out);
1265
1266                 spnego_free_data(&spnego);
1267
1268                 return nt_status;
1269         }
1270
1271         default:
1272                 break;
1273         }
1274
1275         smb_panic(__location__);
1276         return NT_STATUS_INTERNAL_ERROR;
1277 }
1278
1279 struct gensec_spnego_update_state {
1280         struct gensec_security *gensec;
1281         struct spnego_state *spnego;
1282         DATA_BLOB full_in;
1283         NTSTATUS status;
1284         DATA_BLOB out;
1285 };
1286
1287 static void gensec_spnego_update_cleanup(struct tevent_req *req,
1288                                          enum tevent_req_state req_state)
1289 {
1290         struct gensec_spnego_update_state *state =
1291                 tevent_req_data(req,
1292                 struct gensec_spnego_update_state);
1293
1294         switch (req_state) {
1295         case TEVENT_REQ_USER_ERROR:
1296         case TEVENT_REQ_TIMED_OUT:
1297         case TEVENT_REQ_NO_MEMORY:
1298                 /*
1299                  * A fatal error, further updates are not allowed.
1300                  */
1301                 state->spnego->state_position = SPNEGO_DONE;
1302                 break;
1303         default:
1304                 break;
1305         }
1306 }
1307
1308 static NTSTATUS gensec_spnego_update_in(struct gensec_security *gensec_security,
1309                                         const DATA_BLOB in, TALLOC_CTX *mem_ctx,
1310                                         DATA_BLOB *full_in);
1311 static NTSTATUS gensec_spnego_update_out(struct gensec_security *gensec_security,
1312                                          TALLOC_CTX *out_mem_ctx,
1313                                          DATA_BLOB *_out);
1314
1315 static struct tevent_req *gensec_spnego_update_send(TALLOC_CTX *mem_ctx,
1316                                                     struct tevent_context *ev,
1317                                                     struct gensec_security *gensec_security,
1318                                                     const DATA_BLOB in)
1319 {
1320         struct spnego_state *spnego_state =
1321                 talloc_get_type_abort(gensec_security->private_data,
1322                 struct spnego_state);
1323         struct tevent_req *req = NULL;
1324         struct gensec_spnego_update_state *state = NULL;
1325         NTSTATUS status;
1326
1327         req = tevent_req_create(mem_ctx, &state,
1328                                 struct gensec_spnego_update_state);
1329         if (req == NULL) {
1330                 return NULL;
1331         }
1332         state->gensec = gensec_security;
1333         state->spnego = spnego_state;
1334         tevent_req_set_cleanup_fn(req, gensec_spnego_update_cleanup);
1335
1336         if (spnego_state->out_frag.length > 0) {
1337                 if (in.length > 0) {
1338                         tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
1339                         return tevent_req_post(req, ev);
1340                 }
1341
1342                 status = gensec_spnego_update_out(gensec_security,
1343                                                   state, &state->out);
1344                 state->status = status;
1345                 if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
1346                         tevent_req_done(req);
1347                         return tevent_req_post(req, ev);
1348                 }
1349                 if (tevent_req_nterror(req, status)) {
1350                         return tevent_req_post(req, ev);
1351                 }
1352
1353                 tevent_req_done(req);
1354                 return tevent_req_post(req, ev);
1355         }
1356
1357         status = gensec_spnego_update_in(gensec_security, in,
1358                                          state, &state->full_in);
1359         state->status = status;
1360         if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
1361                 tevent_req_done(req);
1362                 return tevent_req_post(req, ev);
1363         }
1364         if (tevent_req_nterror(req, status)) {
1365                 return tevent_req_post(req, ev);
1366         }
1367
1368         /* and switch into the state machine */
1369
1370         switch (spnego_state->state_position) {
1371         case SPNEGO_FALLBACK:
1372                 status = gensec_update_ev(spnego_state->sub_sec_security,
1373                                           state, ev,
1374                                           state->full_in,
1375                                           &spnego_state->out_frag);
1376                 break;
1377
1378         case SPNEGO_CLIENT_START:
1379         case SPNEGO_CLIENT_TARG:
1380                 status = gensec_spnego_update_client(gensec_security,
1381                                                      state, ev,
1382                                                      state->full_in,
1383                                                      &spnego_state->out_frag);
1384                 break;
1385
1386         case SPNEGO_SERVER_START:
1387         case SPNEGO_SERVER_TARG:
1388                 status = gensec_spnego_update_server(gensec_security,
1389                                                      state, ev,
1390                                                      state->full_in,
1391                                                      &spnego_state->out_frag);
1392                 break;
1393
1394         default:
1395                 smb_panic(__location__);
1396                 return NULL;
1397         }
1398
1399         if (NT_STATUS_IS_OK(status)) {
1400                 bool reset_full = true;
1401
1402                 reset_full = !spnego_state->done_mic_check;
1403
1404                 status = gensec_may_reset_crypto(spnego_state->sub_sec_security,
1405                                                  reset_full);
1406         }
1407         if (!NT_STATUS_IS_OK(status) &&
1408             !NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
1409                 tevent_req_nterror(req, status);
1410                 return tevent_req_post(req, ev);
1411         }
1412
1413         spnego_state->out_status = status;
1414
1415         status = gensec_spnego_update_out(gensec_security,
1416                                           state, &state->out);
1417         state->status = status;
1418         if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
1419                 tevent_req_done(req);
1420                 return tevent_req_post(req, ev);
1421         }
1422         if (tevent_req_nterror(req, status)) {
1423                 return tevent_req_post(req, ev);
1424         }
1425
1426         tevent_req_done(req);
1427         return tevent_req_post(req, ev);
1428 }
1429
1430 static NTSTATUS gensec_spnego_update_in(struct gensec_security *gensec_security,
1431                                         const DATA_BLOB in, TALLOC_CTX *mem_ctx,
1432                                         DATA_BLOB *full_in)
1433 {
1434         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
1435         size_t expected;
1436         bool ok;
1437
1438         *full_in = data_blob_null;
1439
1440         switch (spnego_state->state_position) {
1441         case SPNEGO_FALLBACK:
1442                 *full_in = in;
1443                 spnego_state->in_needed = 0;
1444                 return NT_STATUS_OK;
1445
1446         case SPNEGO_CLIENT_START:
1447         case SPNEGO_CLIENT_TARG:
1448         case SPNEGO_SERVER_START:
1449         case SPNEGO_SERVER_TARG:
1450                 break;
1451
1452         case SPNEGO_DONE:
1453         default:
1454                 return NT_STATUS_INVALID_PARAMETER;
1455         }
1456
1457         if (spnego_state->in_needed == 0) {
1458                 size_t size = 0;
1459                 int ret;
1460
1461                 /*
1462                  * try to work out the size of the full
1463                  * input token, it might be fragmented
1464                  */
1465                 ret = asn1_peek_full_tag(in,  ASN1_APPLICATION(0), &size);
1466                 if ((ret != 0) && (ret != EAGAIN)) {
1467                         ret = asn1_peek_full_tag(in, ASN1_CONTEXT(1), &size);
1468                 }
1469
1470                 if ((ret == 0) || (ret == EAGAIN)) {
1471                         spnego_state->in_needed = size;
1472                 } else {
1473                         /*
1474                          * If it is not an asn1 message
1475                          * just call the next layer.
1476                          */
1477                         spnego_state->in_needed = in.length;
1478                 }
1479         }
1480
1481         if (spnego_state->in_needed > UINT16_MAX) {
1482                 /*
1483                  * limit the incoming message to 0xFFFF
1484                  * to avoid DoS attacks.
1485                  */
1486                 return NT_STATUS_INVALID_BUFFER_SIZE;
1487         }
1488
1489         if ((spnego_state->in_needed > 0) && (in.length == 0)) {
1490                 /*
1491                  * If we reach this, we know we got at least
1492                  * part of an asn1 message, getting 0 means
1493                  * the remote peer wants us to spin.
1494                  */
1495                 return NT_STATUS_INVALID_PARAMETER;
1496         }
1497
1498         expected = spnego_state->in_needed - spnego_state->in_frag.length;
1499         if (in.length > expected) {
1500                 /*
1501                  * we got more than expected
1502                  */
1503                 return NT_STATUS_INVALID_PARAMETER;
1504         }
1505
1506         if (in.length == spnego_state->in_needed) {
1507                 /*
1508                  * if the in.length contains the full blob
1509                  * we are done.
1510                  *
1511                  * Note: this implies spnego_state->in_frag.length == 0,
1512                  *       but we do not need to check this explicitly
1513                  *       because we already know that we did not get
1514                  *       more than expected.
1515                  */
1516                 *full_in = in;
1517                 spnego_state->in_needed = 0;
1518                 return NT_STATUS_OK;
1519         }
1520
1521         ok = data_blob_append(spnego_state, &spnego_state->in_frag,
1522                               in.data, in.length);
1523         if (!ok) {
1524                 return NT_STATUS_NO_MEMORY;
1525         }
1526
1527         if (spnego_state->in_needed > spnego_state->in_frag.length) {
1528                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
1529         }
1530
1531         *full_in = spnego_state->in_frag;
1532         talloc_steal(mem_ctx, full_in->data);
1533         spnego_state->in_frag = data_blob_null;
1534         spnego_state->in_needed = 0;
1535         return NT_STATUS_OK;
1536 }
1537
1538 static NTSTATUS gensec_spnego_update_out(struct gensec_security *gensec_security,
1539                                          TALLOC_CTX *out_mem_ctx,
1540                                          DATA_BLOB *_out)
1541 {
1542         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
1543         DATA_BLOB out = data_blob_null;
1544         bool ok;
1545
1546         *_out = data_blob_null;
1547
1548         if (spnego_state->out_frag.length <= spnego_state->out_max_length) {
1549                 /*
1550                  * Fast path, we can deliver everything
1551                  */
1552
1553                 *_out = spnego_state->out_frag;
1554                 if (spnego_state->out_frag.length > 0) {
1555                         talloc_steal(out_mem_ctx, _out->data);
1556                         spnego_state->out_frag = data_blob_null;
1557                 }
1558
1559                 if (!NT_STATUS_IS_OK(spnego_state->out_status)) {
1560                         return spnego_state->out_status;
1561                 }
1562
1563                 /*
1564                  * We're completely done, further updates are not allowed.
1565                  */
1566                 spnego_state->state_position = SPNEGO_DONE;
1567                 return gensec_child_ready(gensec_security,
1568                                           spnego_state->sub_sec_security);
1569         }
1570
1571         out = spnego_state->out_frag;
1572
1573         /*
1574          * copy the remaining bytes
1575          */
1576         spnego_state->out_frag = data_blob_talloc(spnego_state,
1577                                         out.data + spnego_state->out_max_length,
1578                                         out.length - spnego_state->out_max_length);
1579         if (spnego_state->out_frag.data == NULL) {
1580                 return NT_STATUS_NO_MEMORY;
1581         }
1582
1583         /*
1584          * truncate the buffer
1585          */
1586         ok = data_blob_realloc(spnego_state, &out,
1587                                spnego_state->out_max_length);
1588         if (!ok) {
1589                 return NT_STATUS_NO_MEMORY;
1590         }
1591
1592         talloc_steal(out_mem_ctx, out.data);
1593         *_out = out;
1594         return NT_STATUS_MORE_PROCESSING_REQUIRED;
1595 }
1596
1597 static NTSTATUS gensec_spnego_update_recv(struct tevent_req *req,
1598                                           TALLOC_CTX *out_mem_ctx,
1599                                           DATA_BLOB *out)
1600 {
1601         struct gensec_spnego_update_state *state =
1602                 tevent_req_data(req,
1603                 struct gensec_spnego_update_state);
1604         NTSTATUS status;
1605
1606         *out = data_blob_null;
1607
1608         if (tevent_req_is_nterror(req, &status)) {
1609                 tevent_req_received(req);
1610                 return status;
1611         }
1612
1613         *out = state->out;
1614         talloc_steal(out_mem_ctx, state->out.data);
1615         status = state->status;
1616         tevent_req_received(req);
1617         return status;
1618 }
1619
1620 static const char *gensec_spnego_oids[] = {
1621         GENSEC_OID_SPNEGO,
1622         NULL
1623 };
1624
1625 static const struct gensec_security_ops gensec_spnego_security_ops = {
1626         .name             = "spnego",
1627         .sasl_name        = "GSS-SPNEGO",
1628         .auth_type        = DCERPC_AUTH_TYPE_SPNEGO,
1629         .oid              = gensec_spnego_oids,
1630         .client_start     = gensec_spnego_client_start,
1631         .server_start     = gensec_spnego_server_start,
1632         .update_send      = gensec_spnego_update_send,
1633         .update_recv      = gensec_spnego_update_recv,
1634         .seal_packet      = gensec_child_seal_packet,
1635         .sign_packet      = gensec_child_sign_packet,
1636         .sig_size         = gensec_child_sig_size,
1637         .max_wrapped_size = gensec_child_max_wrapped_size,
1638         .max_input_size   = gensec_child_max_input_size,
1639         .check_packet     = gensec_child_check_packet,
1640         .unseal_packet    = gensec_child_unseal_packet,
1641         .wrap             = gensec_child_wrap,
1642         .unwrap           = gensec_child_unwrap,
1643         .session_key      = gensec_child_session_key,
1644         .session_info     = gensec_child_session_info,
1645         .want_feature     = gensec_child_want_feature,
1646         .have_feature     = gensec_child_have_feature,
1647         .expire_time      = gensec_child_expire_time,
1648         .final_auth_type  = gensec_child_final_auth_type,
1649         .enabled          = true,
1650         .priority         = GENSEC_SPNEGO
1651 };
1652
1653 _PUBLIC_ NTSTATUS gensec_spnego_init(TALLOC_CTX *ctx)
1654 {
1655         NTSTATUS ret;
1656         ret = gensec_register(ctx, &gensec_spnego_security_ops);
1657         if (!NT_STATUS_IS_OK(ret)) {
1658                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1659                         gensec_spnego_security_ops.name));
1660                 return ret;
1661         }
1662
1663         return ret;
1664 }