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                                                   TALLOC_CTX *mem_ctx,
 144                                                   const DATA_BLOB in)
 145 {
 146         int i,j;
 147         const struct gensec_security_ops **all_ops;
 148
 149         all_ops = gensec_security_mechs(gensec_security, mem_ctx);
 150
 151         for (i=0; all_ops && all_ops[i]; i++) {
 152                 bool is_spnego;
 153                 NTSTATUS nt_status;
 154
 155                 if (gensec_security != NULL &&
 156                     !gensec_security_ops_enabled(all_ops[i], gensec_security))
 157                 {
 158                         continue;
 159                 }
 160
 161                 if (!all_ops[i]->oid) {
 162                         continue;
 163                 }
 164
 165                 is_spnego = false;
 166                 for (j=0; all_ops[i]->oid[j]; j++) {
 167                         if (strcasecmp(GENSEC_OID_SPNEGO,all_ops[i]->oid[j]) == 0) {
 168                                 is_spnego = true;
 169                         }
 170                 }
 171                 if (is_spnego) {
 172                         continue;
 173                 }
 174
 175                 if (!all_ops[i]->magic) {
 176                         continue;
 177                 }
 178
 179                 nt_status = all_ops[i]->magic(gensec_security, &in);
 180                 if (!NT_STATUS_IS_OK(nt_status)) {
 181                         continue;
 182                 }
 183
 184                 spnego_state->state_position = SPNEGO_FALLBACK;
 185
 186                 nt_status = gensec_subcontext_start(spnego_state,
 187                                                     gensec_security,
 188                                                     &spnego_state->sub_sec_security);
 189
 190                 if (!NT_STATUS_IS_OK(nt_status)) {
 191                         return nt_status;
 192                 }
 193                 /* select the sub context */
 194                 nt_status = gensec_start_mech_by_ops(spnego_state->sub_sec_security,
 195                                                      all_ops[i]);
 196                 if (!NT_STATUS_IS_OK(nt_status)) {
 197                         return nt_status;
 198                 }
 199
 200                 return NT_STATUS_OK;
 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                                                  struct spnego_data *spnego_in,
 216                                                  DATA_BLOB *unwrapped_out)
 217 {
 218         int i;
 219         NTSTATUS nt_status = NT_STATUS_INVALID_PARAMETER;
 220         const char * const *mechType = NULL;
 221         DATA_BLOB unwrapped_in = data_blob_null;
 222         bool ok;
 223         const struct gensec_security_ops_wrapper *all_sec = NULL;
 224
 225         if (spnego_in->type != SPNEGO_NEG_TOKEN_INIT) {
 226                 return NT_STATUS_INTERNAL_ERROR;
 227         }
 228
 229         mechType = spnego_in->negTokenInit.mechTypes;
 230         unwrapped_in = spnego_in->negTokenInit.mechToken;
 231
 232         all_sec = gensec_security_by_oid_list(gensec_security,
 233                                               out_mem_ctx,
 234                                               mechType,
 235                                               GENSEC_OID_SPNEGO);
 236
 237         ok = spnego_write_mech_types(spnego_state,
 238                                      mechType,
 239                                      &spnego_state->mech_types);
 240         if (!ok) {
 241                 DEBUG(1, ("SPNEGO: Failed to write mechTypes\n"));
 242                 return NT_STATUS_NO_MEMORY;
 243         }
 244
 245         if (spnego_state->state_position == SPNEGO_SERVER_START) {
 246                 uint32_t j;
 247                 for (j=0; mechType && mechType[j]; j++) {
 248                         for (i=0; all_sec && all_sec[i].op; i++) {
 249                                 if (strcmp(mechType[j], all_sec[i].oid) != 0) {
 250                                         continue;
 251                                 }
 252
 253                                 nt_status = gensec_subcontext_start(spnego_state,
 254                                                                     gensec_security,
 255                                                                     &spnego_state->sub_sec_security);
 256                                 if (!NT_STATUS_IS_OK(nt_status)) {
 257                                         return nt_status;
 258                                 }
 259                                 /* select the sub context */
 260                                 nt_status = gensec_start_mech_by_ops(spnego_state->sub_sec_security,
 261                                                                      all_sec[i].op);
 262                                 if (!NT_STATUS_IS_OK(nt_status)) {
 263                                         /*
 264                                          * Pretend we never started it
 265                                          */
 266                                         gensec_spnego_update_sub_abort(spnego_state);
 267                                         break;
 268                                 }
 269
 270                                 if (j > 0) {
 271                                         /* no optimistic token */
 272                                         spnego_state->neg_oid = all_sec[i].oid;
 273                                         *unwrapped_out = data_blob_null;
 274                                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 275                                         /*
 276                                          * Indicate the downgrade and request a
 277                                          * mic.
 278                                          */
 279                                         spnego_state->downgraded = true;
 280                                         spnego_state->mic_requested = true;
 281                                         break;
 282                                 }
 283
 284                                 nt_status = gensec_update_ev(spnego_state->sub_sec_security,
 285                                                           out_mem_ctx,
 286                                                           ev,
 287                                                           unwrapped_in,
 288                                                           unwrapped_out);
 289                                 if (NT_STATUS_IS_OK(nt_status)) {
 290                                         spnego_state->sub_sec_ready = true;
 291                                 }
 292                                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_PARAMETER) ||
 293                                     NT_STATUS_EQUAL(nt_status, NT_STATUS_CANT_ACCESS_DOMAIN_INFO)) {
 294
 295                                         DEBUG(1, ("SPNEGO(%s) NEG_TOKEN_INIT failed to parse contents: %s\n",
 296                                                   spnego_state->sub_sec_security->ops->name, nt_errstr(nt_status)));
 297
 298                                         /*
 299                                          * Pretend we never started it
 300                                          */
 301                                         gensec_spnego_update_sub_abort(spnego_state);
 302                                         break;
 303                                 }
 304
 305                                 spnego_state->neg_oid = all_sec[i].oid;
 306                                 break;
 307                         }
 308                         if (spnego_state->sub_sec_security) {
 309                                 break;
 310                         }
 311                 }
 312
 313                 if (!spnego_state->sub_sec_security) {
 314                         DEBUG(1, ("SPNEGO: Could not find a suitable mechtype in NEG_TOKEN_INIT\n"));
 315                         return NT_STATUS_INVALID_PARAMETER;
 316                 }
 317         }
 318
 319         /* Having tried any optimistic token from the client (if we
 320          * were the server), if we didn't get anywhere, walk our list
 321          * in our preference order */
 322         unwrapped_in = data_blob_null;
 323
 324         if (!spnego_state->sub_sec_security) {
 325                 for (i=0; all_sec && all_sec[i].op; i++) {
 326                         nt_status = gensec_subcontext_start(spnego_state,
 327                                                             gensec_security,
 328                                                             &spnego_state->sub_sec_security);
 329                         if (!NT_STATUS_IS_OK(nt_status)) {
 330                                 return nt_status;
 331                         }
 332                         /* select the sub context */
 333                         nt_status = gensec_start_mech_by_ops(spnego_state->sub_sec_security,
 334                                                              all_sec[i].op);
 335                         if (!NT_STATUS_IS_OK(nt_status)) {
 336                                 /*
 337                                  * Pretend we never started it.
 338                                  */
 339                                 gensec_spnego_update_sub_abort(spnego_state);
 340                                 continue;
 341                         }
 342
 343                         spnego_state->neg_oid = all_sec[i].oid;
 344
 345                         /* only get the helping start blob for the first OID */
 346                         nt_status = gensec_update_ev(spnego_state->sub_sec_security,
 347                                                   out_mem_ctx,
 348                                                   ev,
 349                                                   unwrapped_in,
 350                                                   unwrapped_out);
 351                         if (NT_STATUS_IS_OK(nt_status)) {
 352                                 spnego_state->sub_sec_ready = true;
 353                         }
 354
 355                         /* it is likely that a NULL input token will
 356                          * not be liked by most server mechs, but if
 357                          * we are in the client, we want the first
 358                          * update packet to be able to abort the use
 359                          * of this mech */
 360                         if (spnego_state->state_position != SPNEGO_SERVER_START) {
 361                                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_PARAMETER) ||
 362                                     NT_STATUS_EQUAL(nt_status, NT_STATUS_NO_LOGON_SERVERS) ||
 363                                     NT_STATUS_EQUAL(nt_status, NT_STATUS_TIME_DIFFERENCE_AT_DC) ||
 364                                     NT_STATUS_EQUAL(nt_status, NT_STATUS_CANT_ACCESS_DOMAIN_INFO)) {
 365                                         const char *next = NULL;
 366                                         const char *principal = NULL;
 367                                         int dbg_level = DBGLVL_WARNING;
 368
 369                                         if (all_sec[i+1].op != NULL) {
 370                                                 next = all_sec[i+1].op->name;
 371                                                 dbg_level = DBGLVL_NOTICE;
 372                                         }
 373
 374                                         if (gensec_security->target.principal != NULL) {
 375                                                 principal = gensec_security->target.principal;
 376                                         } else if (gensec_security->target.service != NULL &&
 377                                                    gensec_security->target.hostname != NULL)
 378                                         {
 379                                                 principal = talloc_asprintf(spnego_state->sub_sec_security,
 380                                                                             "%s/%s",
 381                                                                             gensec_security->target.service,
 382                                                                             gensec_security->target.hostname);
 383                                         } else {
 384                                                 principal = gensec_security->target.hostname;
 385                                         }
 386
 387                                         DEBUG(dbg_level, ("SPNEGO(%s) creating NEG_TOKEN_INIT for %s failed (next[%s]): %s\n",
 388                                                           spnego_state->sub_sec_security->ops->name,
 389                                                           principal,
 390                                                           next, nt_errstr(nt_status)));
 391
 392                                         /*
 393                                          * Pretend we never started it.
 394                                          */
 395                                         gensec_spnego_update_sub_abort(spnego_state);
 396                                         continue;
 397                                 }
 398                         }
 399
 400                         break;
 401                 }
 402         }
 403
 404         if (spnego_state->sub_sec_security) {
 405                 /* it is likely that a NULL input token will
 406                  * not be liked by most server mechs, but this
 407                  * does the right thing in the CIFS client.
 408                  * just push us along the merry-go-round
 409                  * again, and hope for better luck next
 410                  * time */
 411
 412                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_PARAMETER)) {
 413                         *unwrapped_out = data_blob_null;
 414                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 415                 }
 416
 417                 if (GENSEC_UPDATE_IS_NTERROR(nt_status)) {
 418                         DEBUG(1, ("SPNEGO(%s) NEG_TOKEN_INIT failed: %s\n",
 419                                   spnego_state->sub_sec_security->ops->name, nt_errstr(nt_status)));
 420
 421                         /* We started the mech correctly, and the
 422                          * input from the other side was valid.
 423                          * Return the error (say bad password, invalid
 424                          * ticket) */
 425                         gensec_spnego_update_sub_abort(spnego_state);
 426                         return nt_status;
 427                 }
 428
 429                 return nt_status; /* OK or MORE PROCESSING */
 430         }
 431
 432         DEBUG(1, ("SPNEGO: Could not find a suitable mechtype in NEG_TOKEN_INIT\n"));
 433         /* we could re-negotiate here, but it would only work
 434          * if the client or server lied about what it could
 435          * support the first time.  Lets keep this code to
 436          * reality */
 437
 438         return nt_status;
 439 }
 440
 441 /** create a negTokenInit
 442  *
 443  * This is the same packet, no matter if the client or server sends it first, but it is always the first packet
 444 */
 445 static NTSTATUS gensec_spnego_create_negTokenInit(struct gensec_security *gensec_security,
 446                                                   struct spnego_state *spnego_state,
 447                                                   TALLOC_CTX *out_mem_ctx,
 448                                                   struct tevent_context *ev,
 449                                                   DATA_BLOB *out)
 450 {
 451         int i;
 452         NTSTATUS nt_status = NT_STATUS_INVALID_PARAMETER;
 453         const char **mechTypes = NULL;
 454         DATA_BLOB unwrapped_out = data_blob_null;
 455         const struct gensec_security_ops_wrapper *all_sec;
 456
 457         mechTypes = gensec_security_oids(gensec_security,
 458                                          out_mem_ctx, GENSEC_OID_SPNEGO);
 459
 460         all_sec = gensec_security_by_oid_list(gensec_security,
 461                                               out_mem_ctx,
 462                                               mechTypes,
 463                                               GENSEC_OID_SPNEGO);
 464         for (i=0; all_sec && all_sec[i].op; i++) {
 465                 struct spnego_data spnego_out;
 466                 const char **send_mech_types;
 467                 bool ok;
 468
 469                 nt_status = gensec_subcontext_start(spnego_state,
 470                                                     gensec_security,
 471                                                     &spnego_state->sub_sec_security);
 472                 if (!NT_STATUS_IS_OK(nt_status)) {
 473                         return nt_status;
 474                 }
 475                 /* select the sub context */
 476                 nt_status = gensec_start_mech_by_ops(spnego_state->sub_sec_security,
 477                                                      all_sec[i].op);
 478                 if (!NT_STATUS_IS_OK(nt_status)) {
 479                         gensec_spnego_update_sub_abort(spnego_state);
 480                         continue;
 481                 }
 482
 483                 /* In the client, try and produce the first (optimistic) packet */
 484                 if (spnego_state->state_position == SPNEGO_CLIENT_START) {
 485                         nt_status = gensec_update_ev(spnego_state->sub_sec_security,
 486                                                   out_mem_ctx,
 487                                                   ev,
 488                                                   data_blob_null,
 489                                                   &unwrapped_out);
 490                         if (NT_STATUS_IS_OK(nt_status)) {
 491                                 spnego_state->sub_sec_ready = true;
 492                         }
 493
 494                         if (GENSEC_UPDATE_IS_NTERROR(nt_status)) {
 495                                 const char *next = NULL;
 496                                 const char *principal = NULL;
 497                                 int dbg_level = DBGLVL_WARNING;
 498
 499                                 if (all_sec[i+1].op != NULL) {
 500                                         next = all_sec[i+1].op->name;
 501                                         dbg_level = DBGLVL_NOTICE;
 502                                 }
 503
 504                                 if (gensec_security->target.principal != NULL) {
 505                                         principal = gensec_security->target.principal;
 506                                 } else if (gensec_security->target.service != NULL &&
 507                                            gensec_security->target.hostname != NULL)
 508                                 {
 509                                         principal = talloc_asprintf(spnego_state->sub_sec_security,
 510                                                                     "%s/%s",
 511                                                                     gensec_security->target.service,
 512                                                                     gensec_security->target.hostname);
 513                                 } else {
 514                                         principal = gensec_security->target.hostname;
 515                                 }
 516
 517                                 DEBUG(dbg_level, ("SPNEGO(%s) creating NEG_TOKEN_INIT for %s failed (next[%s]): %s\n",
 518                                           spnego_state->sub_sec_security->ops->name,
 519                                           principal,
 520                                           next, nt_errstr(nt_status)));
 521
 522                                 /*
 523                                  * Pretend we never started it
 524                                  */
 525                                 gensec_spnego_update_sub_abort(spnego_state);
 526                                 continue;
 527                         }
 528                 }
 529
 530                 spnego_out.type = SPNEGO_NEG_TOKEN_INIT;
 531
 532                 send_mech_types = gensec_security_oids_from_ops_wrapped(out_mem_ctx,
 533                                                                         &all_sec[i]);
 534
 535                 ok = spnego_write_mech_types(spnego_state,
 536                                              send_mech_types,
 537                                              &spnego_state->mech_types);
 538                 if (!ok) {
 539                         DEBUG(1, ("SPNEGO: Failed to write mechTypes\n"));
 540                         return NT_STATUS_NO_MEMORY;
 541                 }
 542
 543                 /* List the remaining mechs as options */
 544                 spnego_out.negTokenInit.mechTypes = send_mech_types;
 545                 spnego_out.negTokenInit.reqFlags = data_blob_null;
 546                 spnego_out.negTokenInit.reqFlagsPadding = 0;
 547
 548                 if (spnego_state->state_position == SPNEGO_SERVER_START) {
 549                         spnego_out.negTokenInit.mechListMIC
 550                                 = data_blob_string_const(ADS_IGNORE_PRINCIPAL);
 551                 } else {
 552                         spnego_out.negTokenInit.mechListMIC = data_blob_null;
 553                 }
 554
 555                 spnego_out.negTokenInit.mechToken = unwrapped_out;
 556
 557                 if (spnego_write_data(out_mem_ctx, out, &spnego_out) == -1) {
 558                         DEBUG(1, ("Failed to write NEG_TOKEN_INIT\n"));
 559                                 return NT_STATUS_INVALID_PARAMETER;
 560                 }
 561
 562                 /* set next state */
 563                 spnego_state->neg_oid = all_sec[i].oid;
 564
 565                 if (spnego_state->state_position == SPNEGO_SERVER_START) {
 566                         spnego_state->state_position = SPNEGO_SERVER_START;
 567                         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_INIT;
 568                 } else {
 569                         spnego_state->state_position = SPNEGO_CLIENT_TARG;
 570                         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_TARG;
 571                 }
 572
 573                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 574         }
 575         gensec_spnego_update_sub_abort(spnego_state);
 576
 577         DEBUG(10, ("Failed to setup SPNEGO negTokenInit request: %s\n", nt_errstr(nt_status)));
 578         return nt_status;
 579 }
 580
 581 static NTSTATUS gensec_spnego_client_negTokenInit(struct gensec_security *gensec_security,
 582                                                   struct spnego_state *spnego_state,
 583                                                   struct tevent_context *ev,
 584                                                   struct spnego_data *spnego_in,
 585                                                   TALLOC_CTX *out_mem_ctx,
 586                                                   DATA_BLOB *out)
 587 {
 588         DATA_BLOB sub_out = data_blob_null;
 589         const char *tp = NULL;
 590         struct spnego_data spnego_out;
 591         const char *my_mechs[] = {NULL, NULL};
 592         NTSTATUS status;
 593         bool ok;
 594
 595         *out = data_blob_null;
 596
 597         /* The server offers a list of mechanisms */
 598
 599         tp = spnego_in->negTokenInit.targetPrincipal;
 600         if (tp != NULL && strcmp(tp, ADS_IGNORE_PRINCIPAL) != 0) {
 601                 DBG_INFO("Server claims it's principal name is %s\n", tp);
 602                 if (lpcfg_client_use_spnego_principal(gensec_security->settings->lp_ctx)) {
 603                         gensec_set_target_principal(gensec_security, tp);
 604                 }
 605         }
 606
 607         status = gensec_spnego_parse_negTokenInit(gensec_security,
 608                                                   spnego_state,
 609                                                   out_mem_ctx,
 610                                                   ev,
 611                                                   spnego_in,
 612                                                   &sub_out);
 613         if (GENSEC_UPDATE_IS_NTERROR(status)) {
 614                 return status;
 615         }
 616
 617         my_mechs[0] = spnego_state->neg_oid;
 618         /* compose reply */
 619         spnego_out.type = SPNEGO_NEG_TOKEN_INIT;
 620         spnego_out.negTokenInit.mechTypes = my_mechs;
 621         spnego_out.negTokenInit.reqFlags = data_blob_null;
 622         spnego_out.negTokenInit.reqFlagsPadding = 0;
 623         spnego_out.negTokenInit.mechListMIC = data_blob_null;
 624         spnego_out.negTokenInit.mechToken = sub_out;
 625
 626         if (spnego_write_data(out_mem_ctx, out, &spnego_out) == -1) {
 627                 DBG_ERR("Failed to write SPNEGO reply to NEG_TOKEN_INIT\n");
 628                 return NT_STATUS_INVALID_PARAMETER;
 629         }
 630
 631         ok = spnego_write_mech_types(spnego_state,
 632                                      my_mechs,
 633                                      &spnego_state->mech_types);
 634         if (!ok) {
 635                 DBG_ERR("failed to write mechTypes\n");
 636                 return NT_STATUS_NO_MEMORY;
 637         }
 638
 639         /* set next state */
 640         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_TARG;
 641         spnego_state->state_position = SPNEGO_CLIENT_TARG;
 642
 643         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 644 }
 645
 646 /** create a server negTokenTarg
 647  *
 648  * This is the case, where the client is the first one who sends data
 649 */
 650
 651 static NTSTATUS gensec_spnego_server_response(struct spnego_state *spnego_state,
 652                                               TALLOC_CTX *out_mem_ctx,
 653                                               NTSTATUS nt_status,
 654                                               const DATA_BLOB unwrapped_out,
 655                                               DATA_BLOB mech_list_mic,
 656                                               DATA_BLOB *out)
 657 {
 658         struct spnego_data spnego_out;
 659
 660         /* compose reply */
 661         spnego_out.type = SPNEGO_NEG_TOKEN_TARG;
 662         spnego_out.negTokenTarg.responseToken = unwrapped_out;
 663         spnego_out.negTokenTarg.mechListMIC = mech_list_mic;
 664         spnego_out.negTokenTarg.supportedMech = NULL;
 665
 666         if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 667                 spnego_out.negTokenTarg.supportedMech = spnego_state->neg_oid;
 668                 if (spnego_state->mic_requested) {
 669                         spnego_out.negTokenTarg.negResult = SPNEGO_REQUEST_MIC;
 670                         spnego_state->mic_requested = false;
 671                 } else {
 672                         spnego_out.negTokenTarg.negResult = SPNEGO_ACCEPT_INCOMPLETE;
 673                 }
 674                 spnego_state->state_position = SPNEGO_SERVER_TARG;
 675         } else if (NT_STATUS_IS_OK(nt_status)) {
 676                 if (unwrapped_out.data) {
 677                         spnego_out.negTokenTarg.supportedMech = spnego_state->neg_oid;
 678                 }
 679                 spnego_out.negTokenTarg.negResult = SPNEGO_ACCEPT_COMPLETED;
 680                 spnego_state->state_position = SPNEGO_DONE;
 681         } else {
 682                 spnego_out.negTokenTarg.negResult = SPNEGO_REJECT;
 683                 spnego_out.negTokenTarg.mechListMIC = data_blob_null;
 684                 DEBUG(2, ("SPNEGO login failed: %s\n", nt_errstr(nt_status)));
 685                 spnego_state->state_position = SPNEGO_DONE;
 686         }
 687
 688         if (spnego_write_data(out_mem_ctx, out, &spnego_out) == -1) {
 689                 DEBUG(1, ("Failed to write SPNEGO reply to NEG_TOKEN_TARG\n"));
 690                 return NT_STATUS_INVALID_PARAMETER;
 691         }
 692
 693         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_TARG;
 694         spnego_state->num_targs++;
 695
 696         return nt_status;
 697 }
 698
 699 static NTSTATUS gensec_spnego_server_negTokenInit(struct gensec_security *gensec_security,
 700                                                   struct spnego_state *spnego_state,
 701                                                   struct tevent_context *ev,
 702                                                   struct spnego_data *spnego_in,
 703                                                   TALLOC_CTX *out_mem_ctx,
 704                                                   DATA_BLOB *out)
 705 {
 706         DATA_BLOB sub_out = data_blob_null;
 707         DATA_BLOB mech_list_mic = data_blob_null;
 708         NTSTATUS status;
 709
 710         status = gensec_spnego_parse_negTokenInit(gensec_security,
 711                                                   spnego_state,
 712                                                   out_mem_ctx,
 713                                                   ev,
 714                                                   spnego_in,
 715                                                   &sub_out);
 716
 717         if (spnego_state->simulate_w2k) {
 718                 /*
 719                  * Windows 2000 returns the unwrapped token
 720                  * also in the mech_list_mic field.
 721                  *
 722                  * In order to verify our client code,
 723                  * we need a way to have a server with this
 724                  * broken behaviour
 725                  */
 726                 mech_list_mic = sub_out;
 727         }
 728
 729         return gensec_spnego_server_response(spnego_state,
 730                                              out_mem_ctx,
 731                                              status,
 732                                              sub_out,
 733                                              mech_list_mic,
 734                                              out);
 735 }
 736
 737 static NTSTATUS gensec_spnego_update_client(struct gensec_security *gensec_security,
 738                                             TALLOC_CTX *out_mem_ctx,
 739                                             struct tevent_context *ev,
 740                                             struct spnego_data *spnego_in,
 741                                             DATA_BLOB *out)
 742 {
 743         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 744         DATA_BLOB mech_list_mic = data_blob_null;
 745         DATA_BLOB unwrapped_out = data_blob_null;
 746         struct spnego_data spnego_out;
 747
 748         *out = data_blob_null;
 749
 750         /* and switch into the state machine */
 751
 752         switch (spnego_state->state_position) {
 753         case SPNEGO_CLIENT_START:
 754                 return gensec_spnego_client_negTokenInit(gensec_security,
 755                                                          spnego_state,
 756                                                          ev, spnego_in,
 757                                                          out_mem_ctx, out);
 758
 759         case SPNEGO_CLIENT_TARG:
 760         {
 761                 NTSTATUS nt_status = NT_STATUS_INTERNAL_ERROR;
 762                 struct spnego_negTokenTarg *ta =
 763                         &spnego_in->negTokenTarg;
 764
 765                 spnego_state->num_targs++;
 766
 767                 if (ta->negResult == SPNEGO_REJECT) {
 768                         return NT_STATUS_LOGON_FAILURE;
 769                 }
 770
 771                 if (ta->negResult == SPNEGO_REQUEST_MIC) {
 772                         spnego_state->mic_requested = true;
 773                 }
 774
 775                 /* Server didn't like our choice of mech, and chose something else */
 776                 if (((ta->negResult == SPNEGO_ACCEPT_INCOMPLETE) ||
 777                      (ta->negResult == SPNEGO_REQUEST_MIC)) &&
 778                     ta->supportedMech != NULL&&
 779                     strcmp(ta->supportedMech, spnego_state->neg_oid) != 0) {
 780                         DEBUG(3,("GENSEC SPNEGO: client preferred mech (%s) not accepted, server wants: %s\n",
 781                                  gensec_get_name_by_oid(gensec_security, spnego_state->neg_oid),
 782                                  gensec_get_name_by_oid(gensec_security, ta->supportedMech)));
 783                         spnego_state->downgraded = true;
 784                         gensec_spnego_update_sub_abort(spnego_state);
 785                         nt_status = gensec_subcontext_start(spnego_state,
 786                                                             gensec_security,
 787                                                             &spnego_state->sub_sec_security);
 788                         if (!NT_STATUS_IS_OK(nt_status)) {
 789                                 return nt_status;
 790                         }
 791                         /* select the sub context */
 792                         nt_status = gensec_start_mech_by_oid(spnego_state->sub_sec_security,
 793                                                              ta->supportedMech);
 794                         if (!NT_STATUS_IS_OK(nt_status)) {
 795                                 return nt_status;
 796                         }
 797
 798                         spnego_state->neg_oid = talloc_strdup(spnego_state,
 799                                                 ta->supportedMech);
 800                         if (spnego_state->neg_oid == NULL) {
 801                                 return NT_STATUS_NO_MEMORY;
 802                         };
 803                 }
 804
 805                 if (ta->mechListMIC.length > 0) {
 806                         DATA_BLOB *m = &ta->mechListMIC;
 807                         const DATA_BLOB *r = &ta->responseToken;
 808
 809                         /*
 810                          * Windows 2000 has a bug, it repeats the
 811                          * responseToken in the mechListMIC field.
 812                          */
 813                         if (m->length == r->length) {
 814                                 int cmp;
 815
 816                                 cmp = memcmp(m->data, r->data, m->length);
 817                                 if (cmp == 0) {
 818                                         data_blob_free(m);
 819                                 }
 820                         }
 821                 }
 822
 823                 if (ta->mechListMIC.length > 0) {
 824                         if (spnego_state->sub_sec_ready) {
 825                                 spnego_state->needs_mic_check = true;
 826                         }
 827                 }
 828
 829                 if (spnego_state->needs_mic_check) {
 830                         if (ta->responseToken.length != 0) {
 831                                 DEBUG(1, ("SPNEGO: Did not setup a mech in NEG_TOKEN_INIT\n"));
 832                                 return NT_STATUS_INVALID_PARAMETER;
 833                         }
 834
 835                         if (ta->mechListMIC.length == 0
 836                             && spnego_state->may_skip_mic_check) {
 837                                 /*
 838                                  * In this case we don't require
 839                                  * a mechListMIC from the server.
 840                                  *
 841                                  * This works around bugs in the Azure
 842                                  * and Apple spnego implementations.
 843                                  *
 844                                  * See
 845                                  * https://bugzilla.samba.org/show_bug.cgi?id=11994
 846                                  */
 847                                 spnego_state->needs_mic_check = false;
 848                                 nt_status = NT_STATUS_OK;
 849                                 goto client_response;
 850                         }
 851
 852                         nt_status = gensec_check_packet(spnego_state->sub_sec_security,
 853                                                         spnego_state->mech_types.data,
 854                                                         spnego_state->mech_types.length,
 855                                                         spnego_state->mech_types.data,
 856                                                         spnego_state->mech_types.length,
 857                                                         &ta->mechListMIC);
 858                         if (!NT_STATUS_IS_OK(nt_status)) {
 859                                 DEBUG(2,("GENSEC SPNEGO: failed to verify mechListMIC: %s\n",
 860                                         nt_errstr(nt_status)));
 861                                 return nt_status;
 862                         }
 863                         spnego_state->needs_mic_check = false;
 864                         spnego_state->done_mic_check = true;
 865                         goto client_response;
 866                 }
 867
 868                 if (!spnego_state->sub_sec_ready) {
 869                         nt_status = gensec_update_ev(spnego_state->sub_sec_security,
 870                                                   out_mem_ctx, ev,
 871                                                   ta->responseToken,
 872                                                   &unwrapped_out);
 873                         if (NT_STATUS_IS_OK(nt_status)) {
 874                                 spnego_state->sub_sec_ready = true;
 875                         }
 876                         if (!NT_STATUS_IS_OK(nt_status)) {
 877                                 goto client_response;
 878                         }
 879                 } else {
 880                         nt_status = NT_STATUS_OK;
 881                 }
 882
 883                 if (!spnego_state->done_mic_check) {
 884                         bool have_sign = true;
 885                         bool new_spnego = false;
 886
 887                         have_sign = gensec_have_feature(spnego_state->sub_sec_security,
 888                                                         GENSEC_FEATURE_SIGN);
 889                         if (spnego_state->simulate_w2k) {
 890                                 have_sign = false;
 891                         }
 892                         new_spnego = gensec_have_feature(spnego_state->sub_sec_security,
 893                                                          GENSEC_FEATURE_NEW_SPNEGO);
 894
 895                         switch (ta->negResult) {
 896                         case SPNEGO_ACCEPT_COMPLETED:
 897                         case SPNEGO_NONE_RESULT:
 898                                 if (spnego_state->num_targs == 1) {
 899                                         /*
 900                                          * the first exchange doesn't require
 901                                          * verification
 902                                          */
 903                                         new_spnego = false;
 904                                 }
 905
 906                                 break;
 907
 908                         case SPNEGO_ACCEPT_INCOMPLETE:
 909                                 if (ta->mechListMIC.length > 0) {
 910                                         new_spnego = true;
 911                                         break;
 912                                 }
 913
 914                                 if (spnego_state->downgraded) {
 915                                         /*
 916                                          * A downgrade should be protected if
 917                                          * supported
 918                                          */
 919                                         break;
 920                                 }
 921
 922                                 /*
 923                                  * The caller may just asked for
 924                                  * GENSEC_FEATURE_SESSION_KEY, this
 925                                  * is only reflected in the want_features.
 926                                  *
 927                                  * As it will imply
 928                                  * gensec_have_features(GENSEC_FEATURE_SIGN)
 929                                  * to return true.
 930                                  */
 931                                 if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 932                                         break;
 933                                 }
 934                                 if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 935                                         break;
 936                                 }
 937                                 /*
 938                                  * Here we're sure our preferred mech was
 939                                  * selected by the server and our caller doesn't
 940                                  * need GENSEC_FEATURE_SIGN nor
 941                                  * GENSEC_FEATURE_SEAL support.
 942                                  *
 943                                  * In this case we don't require
 944                                  * a mechListMIC from the server.
 945                                  *
 946                                  * This works around bugs in the Azure
 947                                  * and Apple spnego implementations.
 948                                  *
 949                                  * See
 950                                  * https://bugzilla.samba.org/show_bug.cgi?id=11994
 951                                  */
 952                                 spnego_state->may_skip_mic_check = true;
 953                                 break;
 954
 955                         case SPNEGO_REQUEST_MIC:
 956                                 if (ta->mechListMIC.length > 0) {
 957                                         new_spnego = true;
 958                                 }
 959                                 break;
 960                         default:
 961                                 break;
 962                         }
 963
 964                         if (spnego_state->mic_requested) {
 965                                 if (have_sign) {
 966                                         new_spnego = true;
 967                                 }
 968                         }
 969
 970                         if (have_sign && new_spnego) {
 971                                 spnego_state->needs_mic_check = true;
 972                                 spnego_state->needs_mic_sign = true;
 973                         }
 974                 }
 975
 976                 if (ta->mechListMIC.length > 0) {
 977                         nt_status = gensec_check_packet(spnego_state->sub_sec_security,
 978                                                         spnego_state->mech_types.data,
 979                                                         spnego_state->mech_types.length,
 980                                                         spnego_state->mech_types.data,
 981                                                         spnego_state->mech_types.length,
 982                                                         &ta->mechListMIC);
 983                         if (!NT_STATUS_IS_OK(nt_status)) {
 984                                 DEBUG(2,("GENSEC SPNEGO: failed to verify mechListMIC: %s\n",
 985                                         nt_errstr(nt_status)));
 986                                 return nt_status;
 987                         }
 988                         spnego_state->needs_mic_check = false;
 989                         spnego_state->done_mic_check = true;
 990                 }
 991
 992                 if (spnego_state->needs_mic_sign) {
 993                         nt_status = gensec_sign_packet(spnego_state->sub_sec_security,
 994                                                        out_mem_ctx,
 995                                                        spnego_state->mech_types.data,
 996                                                        spnego_state->mech_types.length,
 997                                                        spnego_state->mech_types.data,
 998                                                        spnego_state->mech_types.length,
 999                                                        &mech_list_mic);
1000                         if (!NT_STATUS_IS_OK(nt_status)) {
1001                                 DEBUG(2,("GENSEC SPNEGO: failed to sign mechListMIC: %s\n",
1002                                         nt_errstr(nt_status)));
1003                                 return nt_status;
1004                         }
1005                         spnego_state->needs_mic_sign = false;
1006                 }
1007
1008                 if (spnego_state->needs_mic_check) {
1009                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
1010                 }
1011
1012  client_response:
1013                 if (GENSEC_UPDATE_IS_NTERROR(nt_status)) {
1014                         DEBUG(1, ("SPNEGO(%s) login failed: %s\n",
1015                                   spnego_state->sub_sec_security->ops->name,
1016                                   nt_errstr(nt_status)));
1017                         return nt_status;
1018                 }
1019
1020                 if (unwrapped_out.length || mech_list_mic.length) {
1021                         /* compose reply */
1022                         spnego_out.type = SPNEGO_NEG_TOKEN_TARG;
1023                         spnego_out.negTokenTarg.negResult = SPNEGO_NONE_RESULT;
1024                         spnego_out.negTokenTarg.supportedMech = NULL;
1025                         spnego_out.negTokenTarg.responseToken = unwrapped_out;
1026                         spnego_out.negTokenTarg.mechListMIC = mech_list_mic;
1027
1028                         if (spnego_write_data(out_mem_ctx, out, &spnego_out) == -1) {
1029                                 DEBUG(1, ("Failed to write SPNEGO reply to NEG_TOKEN_TARG\n"));
1030                                 return NT_STATUS_INVALID_PARAMETER;
1031                         }
1032
1033                         spnego_state->num_targs++;
1034                         spnego_state->state_position = SPNEGO_CLIENT_TARG;
1035                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
1036                 } else {
1037
1038                         /* all done - server has accepted, and we agree */
1039                         *out = data_blob_null;
1040
1041                         if (ta->negResult != SPNEGO_ACCEPT_COMPLETED) {
1042                                 /* unless of course it did not accept */
1043                                 DEBUG(1,("gensec_update ok but not accepted\n"));
1044                                 nt_status = NT_STATUS_INVALID_PARAMETER;
1045                         }
1046
1047                         spnego_state->state_position = SPNEGO_DONE;
1048                 }
1049
1050                 return nt_status;
1051         }
1052
1053         default:
1054                 break;
1055         }
1056
1057         smb_panic(__location__);
1058         return NT_STATUS_INTERNAL_ERROR;
1059 }
1060
1061 static NTSTATUS gensec_spnego_update_server(struct gensec_security *gensec_security,
1062                                             TALLOC_CTX *out_mem_ctx,
1063                                             struct tevent_context *ev,
1064                                             struct spnego_data *spnego_in,
1065                                             DATA_BLOB *out)
1066 {
1067         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
1068         DATA_BLOB mech_list_mic = data_blob_null;
1069         DATA_BLOB unwrapped_out = data_blob_null;
1070
1071         /* and switch into the state machine */
1072
1073         switch (spnego_state->state_position) {
1074         case SPNEGO_SERVER_START:
1075                 return gensec_spnego_server_negTokenInit(gensec_security,
1076                                                          spnego_state,
1077                                                          ev, spnego_in,
1078                                                          out_mem_ctx, out);
1079
1080         case SPNEGO_SERVER_TARG:
1081         {
1082                 NTSTATUS nt_status;
1083                 bool have_sign = true;
1084                 bool new_spnego = false;
1085
1086                 spnego_state->num_targs++;
1087
1088                 if (!spnego_state->sub_sec_security) {
1089                         DEBUG(1, ("SPNEGO: Did not setup a mech in NEG_TOKEN_INIT\n"));
1090                         return NT_STATUS_INVALID_PARAMETER;
1091                 }
1092
1093                 if (spnego_state->needs_mic_check) {
1094                         if (spnego_in->negTokenTarg.responseToken.length != 0) {
1095                                 DEBUG(1, ("SPNEGO: Did not setup a mech in NEG_TOKEN_INIT\n"));
1096                                 return NT_STATUS_INVALID_PARAMETER;
1097                         }
1098
1099                         nt_status = gensec_check_packet(spnego_state->sub_sec_security,
1100                                                         spnego_state->mech_types.data,
1101                                                         spnego_state->mech_types.length,
1102                                                         spnego_state->mech_types.data,
1103                                                         spnego_state->mech_types.length,
1104                                                         &spnego_in->negTokenTarg.mechListMIC);
1105                         if (NT_STATUS_IS_OK(nt_status)) {
1106                                 spnego_state->needs_mic_check = false;
1107                                 spnego_state->done_mic_check = true;
1108                         } else {
1109                                 DEBUG(2,("GENSEC SPNEGO: failed to verify mechListMIC: %s\n",
1110                                         nt_errstr(nt_status)));
1111                         }
1112                         goto server_response;
1113                 }
1114
1115                 if (!spnego_state->sub_sec_ready) {
1116                         nt_status = gensec_update_ev(spnego_state->sub_sec_security,
1117                                                      out_mem_ctx, ev,
1118                                                      spnego_in->negTokenTarg.responseToken,
1119                                                      &unwrapped_out);
1120                         if (NT_STATUS_IS_OK(nt_status)) {
1121                                 spnego_state->sub_sec_ready = true;
1122                         }
1123                         if (!NT_STATUS_IS_OK(nt_status)) {
1124                                 goto server_response;
1125                         }
1126                 } else {
1127                         nt_status = NT_STATUS_OK;
1128                 }
1129
1130                 have_sign = gensec_have_feature(spnego_state->sub_sec_security,
1131                                                 GENSEC_FEATURE_SIGN);
1132                 if (spnego_state->simulate_w2k) {
1133                         have_sign = false;
1134                 }
1135                 new_spnego = gensec_have_feature(spnego_state->sub_sec_security,
1136                                                  GENSEC_FEATURE_NEW_SPNEGO);
1137                 if (spnego_in->negTokenTarg.mechListMIC.length > 0) {
1138                         new_spnego = true;
1139                 }
1140
1141                 if (have_sign && new_spnego) {
1142                         spnego_state->needs_mic_check = true;
1143                         spnego_state->needs_mic_sign = true;
1144                 }
1145
1146                 if (have_sign && spnego_in->negTokenTarg.mechListMIC.length > 0) {
1147                         nt_status = gensec_check_packet(spnego_state->sub_sec_security,
1148                                                         spnego_state->mech_types.data,
1149                                                         spnego_state->mech_types.length,
1150                                                         spnego_state->mech_types.data,
1151                                                         spnego_state->mech_types.length,
1152                                                         &spnego_in->negTokenTarg.mechListMIC);
1153                         if (!NT_STATUS_IS_OK(nt_status)) {
1154                                 DEBUG(2,("GENSEC SPNEGO: failed to verify mechListMIC: %s\n",
1155                                         nt_errstr(nt_status)));
1156                                 goto server_response;
1157                         }
1158
1159                         spnego_state->needs_mic_check = false;
1160                         spnego_state->done_mic_check = true;
1161                 }
1162
1163                 if (spnego_state->needs_mic_sign) {
1164                         nt_status = gensec_sign_packet(spnego_state->sub_sec_security,
1165                                                        out_mem_ctx,
1166                                                        spnego_state->mech_types.data,
1167                                                        spnego_state->mech_types.length,
1168                                                        spnego_state->mech_types.data,
1169                                                        spnego_state->mech_types.length,
1170                                                        &mech_list_mic);
1171                         if (!NT_STATUS_IS_OK(nt_status)) {
1172                                 DEBUG(2,("GENSEC SPNEGO: failed to sign mechListMIC: %s\n",
1173                                         nt_errstr(nt_status)));
1174                                 goto server_response;
1175                         }
1176                         spnego_state->needs_mic_sign = false;
1177                 }
1178
1179                 if (spnego_state->needs_mic_check) {
1180                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
1181                 }
1182
1183  server_response:
1184                 nt_status = gensec_spnego_server_response(spnego_state,
1185                                                           out_mem_ctx,
1186                                                           nt_status,
1187                                                           unwrapped_out,
1188                                                           mech_list_mic,
1189                                                           out);
1190
1191                 return nt_status;
1192         }
1193
1194         default:
1195                 break;
1196         }
1197
1198         smb_panic(__location__);
1199         return NT_STATUS_INTERNAL_ERROR;
1200 }
1201
1202 struct gensec_spnego_update_state {
1203         struct gensec_security *gensec;
1204         struct spnego_state *spnego;
1205         DATA_BLOB full_in;
1206         struct spnego_data _spnego_in;
1207         struct spnego_data *spnego_in;
1208         NTSTATUS status;
1209         DATA_BLOB out;
1210 };
1211
1212 static void gensec_spnego_update_cleanup(struct tevent_req *req,
1213                                          enum tevent_req_state req_state)
1214 {
1215         struct gensec_spnego_update_state *state =
1216                 tevent_req_data(req,
1217                 struct gensec_spnego_update_state);
1218
1219         switch (req_state) {
1220         case TEVENT_REQ_USER_ERROR:
1221         case TEVENT_REQ_TIMED_OUT:
1222         case TEVENT_REQ_NO_MEMORY:
1223                 /*
1224                  * A fatal error, further updates are not allowed.
1225                  */
1226                 state->spnego->state_position = SPNEGO_DONE;
1227                 break;
1228         default:
1229                 break;
1230         }
1231 }
1232
1233 static NTSTATUS gensec_spnego_update_in(struct gensec_security *gensec_security,
1234                                         const DATA_BLOB in, TALLOC_CTX *mem_ctx,
1235                                         DATA_BLOB *full_in);
1236 static NTSTATUS gensec_spnego_update_out(struct gensec_security *gensec_security,
1237                                          TALLOC_CTX *out_mem_ctx,
1238                                          DATA_BLOB *_out);
1239
1240 static struct tevent_req *gensec_spnego_update_send(TALLOC_CTX *mem_ctx,
1241                                                     struct tevent_context *ev,
1242                                                     struct gensec_security *gensec_security,
1243                                                     const DATA_BLOB in)
1244 {
1245         struct spnego_state *spnego_state =
1246                 talloc_get_type_abort(gensec_security->private_data,
1247                 struct spnego_state);
1248         struct tevent_req *req = NULL;
1249         struct gensec_spnego_update_state *state = NULL;
1250         NTSTATUS status;
1251         ssize_t len;
1252
1253         req = tevent_req_create(mem_ctx, &state,
1254                                 struct gensec_spnego_update_state);
1255         if (req == NULL) {
1256                 return NULL;
1257         }
1258         state->gensec = gensec_security;
1259         state->spnego = spnego_state;
1260         tevent_req_set_cleanup_fn(req, gensec_spnego_update_cleanup);
1261
1262         if (spnego_state->out_frag.length > 0) {
1263                 if (in.length > 0) {
1264                         tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
1265                         return tevent_req_post(req, ev);
1266                 }
1267
1268                 status = gensec_spnego_update_out(gensec_security,
1269                                                   state, &state->out);
1270                 if (GENSEC_UPDATE_IS_NTERROR(status)) {
1271                         tevent_req_nterror(req, status);
1272                         return tevent_req_post(req, ev);
1273                 }
1274
1275                 state->status = status;
1276                 tevent_req_done(req);
1277                 return tevent_req_post(req, ev);
1278         }
1279
1280         status = gensec_spnego_update_in(gensec_security, in,
1281                                          state, &state->full_in);
1282         state->status = status;
1283         if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
1284                 tevent_req_done(req);
1285                 return tevent_req_post(req, ev);
1286         }
1287         if (tevent_req_nterror(req, status)) {
1288                 return tevent_req_post(req, ev);
1289         }
1290
1291         /* Check if we got a valid SPNEGO blob... */
1292
1293         switch (spnego_state->state_position) {
1294         case SPNEGO_FALLBACK:
1295                 break;
1296
1297         case SPNEGO_CLIENT_TARG:
1298         case SPNEGO_SERVER_TARG:
1299                 if (state->full_in.length == 0) {
1300                         tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
1301                         return tevent_req_post(req, ev);
1302                 }
1303
1304                 /* fall through */
1305         case SPNEGO_CLIENT_START:
1306         case SPNEGO_SERVER_START:
1307
1308                 if (state->full_in.length == 0) {
1309                         /* create_negTokenInit later */
1310                         break;
1311                 }
1312
1313                 len = spnego_read_data(state,
1314                                        state->full_in,
1315                                        &state->_spnego_in);
1316                 if (len == -1) {
1317                         if (spnego_state->state_position != SPNEGO_SERVER_START) {
1318                                 DEBUG(1, ("Invalid SPNEGO request:\n"));
1319                                 dump_data(1, state->full_in.data,
1320                                           state->full_in.length);
1321                                 tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
1322                                 return tevent_req_post(req, ev);
1323                         }
1324
1325                         /*
1326                          * This is the 'fallback' case, where we don't get
1327                          * SPNEGO, and have to try all the other options (and
1328                          * hope they all have a magic string they check)
1329                          */
1330                         status = gensec_spnego_server_try_fallback(gensec_security,
1331                                                                    spnego_state,
1332                                                                    state,
1333                                                                    state->full_in);
1334                         if (tevent_req_nterror(req, status)) {
1335                                 return tevent_req_post(req, ev);
1336                         }
1337
1338                         /*
1339                          * We'll continue with SPNEGO_FALLBACK below...
1340                          */
1341                         break;
1342                 }
1343                 state->spnego_in = &state->_spnego_in;
1344
1345                 /* OK, so it's real SPNEGO, check the packet's the one we expect */
1346                 if (state->spnego_in->type != spnego_state->expected_packet) {
1347                         DEBUG(1, ("Invalid SPNEGO request: %d, expected %d\n",
1348                                   state->spnego_in->type,
1349                                   spnego_state->expected_packet));
1350                         dump_data(1, state->full_in.data,
1351                                   state->full_in.length);
1352                         tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
1353                         return tevent_req_post(req, ev);
1354                 }
1355
1356                 break;
1357
1358         default:
1359                 smb_panic(__location__);
1360                 return NULL;
1361         }
1362
1363         /* and switch into the state machine */
1364
1365         switch (spnego_state->state_position) {
1366         case SPNEGO_FALLBACK:
1367                 status = gensec_update_ev(spnego_state->sub_sec_security,
1368                                           state, ev,
1369                                           state->full_in,
1370                                           &spnego_state->out_frag);
1371                 break;
1372
1373         case SPNEGO_CLIENT_START:
1374                 if (state->spnego_in == NULL) {
1375                         /* client to produce negTokenInit */
1376                         status = gensec_spnego_create_negTokenInit(gensec_security,
1377                                                         spnego_state, state, ev,
1378                                                         &spnego_state->out_frag);
1379                         break;
1380                 }
1381
1382                 /* fall through */
1383         case SPNEGO_CLIENT_TARG:
1384                 status = gensec_spnego_update_client(gensec_security,
1385                                                      state, ev,
1386                                                      state->spnego_in,
1387                                                      &spnego_state->out_frag);
1388                 break;
1389
1390         case SPNEGO_SERVER_START:
1391                 if (state->spnego_in == NULL) {
1392                         /* server to produce negTokenInit */
1393                         status = gensec_spnego_create_negTokenInit(gensec_security,
1394                                                         spnego_state, state, ev,
1395                                                         &spnego_state->out_frag);
1396                         break;
1397                 }
1398
1399                 /* fall through */
1400         case SPNEGO_SERVER_TARG:
1401                 status = gensec_spnego_update_server(gensec_security,
1402                                                      state, ev,
1403                                                      state->spnego_in,
1404                                                      &spnego_state->out_frag);
1405                 break;
1406
1407         default:
1408                 smb_panic(__location__);
1409                 return NULL;
1410         }
1411
1412         if (GENSEC_UPDATE_IS_NTERROR(status)) {
1413                 tevent_req_nterror(req, status);
1414                 return tevent_req_post(req, ev);
1415         }
1416
1417         if (NT_STATUS_IS_OK(status)) {
1418                 bool reset_full = true;
1419
1420                 reset_full = !spnego_state->done_mic_check;
1421
1422                 status = gensec_may_reset_crypto(spnego_state->sub_sec_security,
1423                                                  reset_full);
1424                 if (tevent_req_nterror(req, status)) {
1425                         return tevent_req_post(req, ev);
1426                 }
1427         }
1428
1429         spnego_state->out_status = status;
1430
1431         status = gensec_spnego_update_out(gensec_security,
1432                                           state, &state->out);
1433         if (GENSEC_UPDATE_IS_NTERROR(status)) {
1434                 tevent_req_nterror(req, status);
1435                 return tevent_req_post(req, ev);
1436         }
1437
1438         state->status = status;
1439         tevent_req_done(req);
1440         return tevent_req_post(req, ev);
1441 }
1442
1443 static NTSTATUS gensec_spnego_update_in(struct gensec_security *gensec_security,
1444                                         const DATA_BLOB in, TALLOC_CTX *mem_ctx,
1445                                         DATA_BLOB *full_in)
1446 {
1447         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
1448         size_t expected;
1449         bool ok;
1450
1451         *full_in = data_blob_null;
1452
1453         switch (spnego_state->state_position) {
1454         case SPNEGO_FALLBACK:
1455                 *full_in = in;
1456                 spnego_state->in_needed = 0;
1457                 return NT_STATUS_OK;
1458
1459         case SPNEGO_CLIENT_START:
1460         case SPNEGO_CLIENT_TARG:
1461         case SPNEGO_SERVER_START:
1462         case SPNEGO_SERVER_TARG:
1463                 break;
1464
1465         case SPNEGO_DONE:
1466         default:
1467                 return NT_STATUS_INVALID_PARAMETER;
1468         }
1469
1470         if (spnego_state->in_needed == 0) {
1471                 size_t size = 0;
1472                 int ret;
1473
1474                 /*
1475                  * try to work out the size of the full
1476                  * input token, it might be fragmented
1477                  */
1478                 ret = asn1_peek_full_tag(in,  ASN1_APPLICATION(0), &size);
1479                 if ((ret != 0) && (ret != EAGAIN)) {
1480                         ret = asn1_peek_full_tag(in, ASN1_CONTEXT(1), &size);
1481                 }
1482
1483                 if ((ret == 0) || (ret == EAGAIN)) {
1484                         spnego_state->in_needed = size;
1485                 } else {
1486                         /*
1487                          * If it is not an asn1 message
1488                          * just call the next layer.
1489                          */
1490                         spnego_state->in_needed = in.length;
1491                 }
1492         }
1493
1494         if (spnego_state->in_needed > UINT16_MAX) {
1495                 /*
1496                  * limit the incoming message to 0xFFFF
1497                  * to avoid DoS attacks.
1498                  */
1499                 return NT_STATUS_INVALID_BUFFER_SIZE;
1500         }
1501
1502         if ((spnego_state->in_needed > 0) && (in.length == 0)) {
1503                 /*
1504                  * If we reach this, we know we got at least
1505                  * part of an asn1 message, getting 0 means
1506                  * the remote peer wants us to spin.
1507                  */
1508                 return NT_STATUS_INVALID_PARAMETER;
1509         }
1510
1511         expected = spnego_state->in_needed - spnego_state->in_frag.length;
1512         if (in.length > expected) {
1513                 /*
1514                  * we got more than expected
1515                  */
1516                 return NT_STATUS_INVALID_PARAMETER;
1517         }
1518
1519         if (in.length == spnego_state->in_needed) {
1520                 /*
1521                  * if the in.length contains the full blob
1522                  * we are done.
1523                  *
1524                  * Note: this implies spnego_state->in_frag.length == 0,
1525                  *       but we do not need to check this explicitly
1526                  *       because we already know that we did not get
1527                  *       more than expected.
1528                  */
1529                 *full_in = in;
1530                 spnego_state->in_needed = 0;
1531                 return NT_STATUS_OK;
1532         }
1533
1534         ok = data_blob_append(spnego_state, &spnego_state->in_frag,
1535                               in.data, in.length);
1536         if (!ok) {
1537                 return NT_STATUS_NO_MEMORY;
1538         }
1539
1540         if (spnego_state->in_needed > spnego_state->in_frag.length) {
1541                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
1542         }
1543
1544         *full_in = spnego_state->in_frag;
1545         talloc_steal(mem_ctx, full_in->data);
1546         spnego_state->in_frag = data_blob_null;
1547         spnego_state->in_needed = 0;
1548         return NT_STATUS_OK;
1549 }
1550
1551 static NTSTATUS gensec_spnego_update_out(struct gensec_security *gensec_security,
1552                                          TALLOC_CTX *out_mem_ctx,
1553                                          DATA_BLOB *_out)
1554 {
1555         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
1556         DATA_BLOB out = data_blob_null;
1557         bool ok;
1558
1559         *_out = data_blob_null;
1560
1561         if (spnego_state->out_frag.length <= spnego_state->out_max_length) {
1562                 /*
1563                  * Fast path, we can deliver everything
1564                  */
1565
1566                 *_out = spnego_state->out_frag;
1567                 if (spnego_state->out_frag.length > 0) {
1568                         talloc_steal(out_mem_ctx, _out->data);
1569                         spnego_state->out_frag = data_blob_null;
1570                 }
1571
1572                 if (!NT_STATUS_IS_OK(spnego_state->out_status)) {
1573                         return spnego_state->out_status;
1574                 }
1575
1576                 /*
1577                  * We're completely done, further updates are not allowed.
1578                  */
1579                 spnego_state->state_position = SPNEGO_DONE;
1580                 return gensec_child_ready(gensec_security,
1581                                           spnego_state->sub_sec_security);
1582         }
1583
1584         out = spnego_state->out_frag;
1585
1586         /*
1587          * copy the remaining bytes
1588          */
1589         spnego_state->out_frag = data_blob_talloc(spnego_state,
1590                                         out.data + spnego_state->out_max_length,
1591                                         out.length - spnego_state->out_max_length);
1592         if (spnego_state->out_frag.data == NULL) {
1593                 return NT_STATUS_NO_MEMORY;
1594         }
1595
1596         /*
1597          * truncate the buffer
1598          */
1599         ok = data_blob_realloc(spnego_state, &out,
1600                                spnego_state->out_max_length);
1601         if (!ok) {
1602                 return NT_STATUS_NO_MEMORY;
1603         }
1604
1605         talloc_steal(out_mem_ctx, out.data);
1606         *_out = out;
1607         return NT_STATUS_MORE_PROCESSING_REQUIRED;
1608 }
1609
1610 static NTSTATUS gensec_spnego_update_recv(struct tevent_req *req,
1611                                           TALLOC_CTX *out_mem_ctx,
1612                                           DATA_BLOB *out)
1613 {
1614         struct gensec_spnego_update_state *state =
1615                 tevent_req_data(req,
1616                 struct gensec_spnego_update_state);
1617         NTSTATUS status;
1618
1619         *out = data_blob_null;
1620
1621         if (tevent_req_is_nterror(req, &status)) {
1622                 tevent_req_received(req);
1623                 return status;
1624         }
1625
1626         *out = state->out;
1627         talloc_steal(out_mem_ctx, state->out.data);
1628         status = state->status;
1629         tevent_req_received(req);
1630         return status;
1631 }
1632
1633 static const char *gensec_spnego_oids[] = {
1634         GENSEC_OID_SPNEGO,
1635         NULL
1636 };
1637
1638 static const struct gensec_security_ops gensec_spnego_security_ops = {
1639         .name             = "spnego",
1640         .sasl_name        = "GSS-SPNEGO",
1641         .auth_type        = DCERPC_AUTH_TYPE_SPNEGO,
1642         .oid              = gensec_spnego_oids,
1643         .client_start     = gensec_spnego_client_start,
1644         .server_start     = gensec_spnego_server_start,
1645         .update_send      = gensec_spnego_update_send,
1646         .update_recv      = gensec_spnego_update_recv,
1647         .seal_packet      = gensec_child_seal_packet,
1648         .sign_packet      = gensec_child_sign_packet,
1649         .sig_size         = gensec_child_sig_size,
1650         .max_wrapped_size = gensec_child_max_wrapped_size,
1651         .max_input_size   = gensec_child_max_input_size,
1652         .check_packet     = gensec_child_check_packet,
1653         .unseal_packet    = gensec_child_unseal_packet,
1654         .wrap             = gensec_child_wrap,
1655         .unwrap           = gensec_child_unwrap,
1656         .session_key      = gensec_child_session_key,
1657         .session_info     = gensec_child_session_info,
1658         .want_feature     = gensec_child_want_feature,
1659         .have_feature     = gensec_child_have_feature,
1660         .expire_time      = gensec_child_expire_time,
1661         .final_auth_type  = gensec_child_final_auth_type,
1662         .enabled          = true,
1663         .priority         = GENSEC_SPNEGO
1664 };
1665
1666 _PUBLIC_ NTSTATUS gensec_spnego_init(TALLOC_CTX *ctx)
1667 {
1668         NTSTATUS ret;
1669         ret = gensec_register(ctx, &gensec_spnego_security_ops);
1670         if (!NT_STATUS_IS_OK(ret)) {
1671                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1672                         gensec_spnego_security_ops.name));
1673                 return ret;
1674         }
1675
1676         return ret;
1677 }