auth/gensec/spnego.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    RFC2478 Compliant SPNEGO implementation
   5
   6    Copyright (C) Jim McDonough <jmcd@us.ibm.com>      2003
   7    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
   8    Copyright (C) Stefan Metzmacher <metze@samba.org>  2004-2008
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  23 */
  24
  25 #include "includes.h"
  26 #include "../libcli/auth/spnego.h"
  27 #include "librpc/gen_ndr/ndr_dcerpc.h"
  28 #include "auth/credentials/credentials.h"
  29 #include "auth/gensec/gensec.h"
  30 #include "param/param.h"
  31 #include "lib/util/asn1.h"
  32
  33 #undef strcasecmp
  34
  35 _PUBLIC_ NTSTATUS gensec_spnego_init(void);
  36
  37 enum spnego_state_position {
  38         SPNEGO_SERVER_START,
  39         SPNEGO_CLIENT_START,
  40         SPNEGO_SERVER_TARG,
  41         SPNEGO_CLIENT_TARG,
  42         SPNEGO_FALLBACK,
  43         SPNEGO_DONE
  44 };
  45
  46 struct spnego_state {
  47         enum spnego_message_type expected_packet;
  48         enum spnego_state_position state_position;
  49         struct gensec_security *sub_sec_security;
  50         bool no_response_expected;
  51
  52         const char *neg_oid;
  53
  54         DATA_BLOB mech_types;
  55
  56         /*
  57          * The following is used to implement
  58          * the update token fragmentation
  59          */
  60         size_t in_needed;
  61         DATA_BLOB in_frag;
  62         size_t out_max_length;
  63         DATA_BLOB out_frag;
  64         NTSTATUS out_status;
  65 };
  66
  67
  68 static NTSTATUS gensec_spnego_client_start(struct gensec_security *gensec_security)
  69 {
  70         struct spnego_state *spnego_state;
  71
  72         spnego_state = talloc_zero(gensec_security, struct spnego_state);
  73         if (!spnego_state) {
  74                 return NT_STATUS_NO_MEMORY;
  75         }
  76
  77         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_INIT;
  78         spnego_state->state_position = SPNEGO_CLIENT_START;
  79         spnego_state->sub_sec_security = NULL;
  80         spnego_state->no_response_expected = false;
  81         spnego_state->mech_types = data_blob(NULL, 0);
  82         spnego_state->out_max_length = gensec_max_update_size(gensec_security);
  83         spnego_state->out_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
  84
  85         gensec_security->private_data = spnego_state;
  86         return NT_STATUS_OK;
  87 }
  88
  89 static NTSTATUS gensec_spnego_server_start(struct gensec_security *gensec_security)
  90 {
  91         struct spnego_state *spnego_state;
  92
  93         spnego_state = talloc_zero(gensec_security, struct spnego_state);
  94         if (!spnego_state) {
  95                 return NT_STATUS_NO_MEMORY;
  96         }
  97
  98         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_INIT;
  99         spnego_state->state_position = SPNEGO_SERVER_START;
 100         spnego_state->sub_sec_security = NULL;
 101         spnego_state->no_response_expected = false;
 102         spnego_state->mech_types = data_blob(NULL, 0);
 103         spnego_state->out_max_length = gensec_max_update_size(gensec_security);
 104         spnego_state->out_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 105
 106         gensec_security->private_data = spnego_state;
 107         return NT_STATUS_OK;
 108 }
 109
 110 /*
 111   wrappers for the spnego_*() functions
 112 */
 113 static NTSTATUS gensec_spnego_unseal_packet(struct gensec_security *gensec_security,
 114                                             uint8_t *data, size_t length,
 115                                             const uint8_t *whole_pdu, size_t pdu_length,
 116                                             const DATA_BLOB *sig)
 117 {
 118         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 119
 120         if (spnego_state->state_position != SPNEGO_DONE
 121             && spnego_state->state_position != SPNEGO_FALLBACK) {
 122                 return NT_STATUS_INVALID_PARAMETER;
 123         }
 124
 125         return gensec_unseal_packet(spnego_state->sub_sec_security,
 126                                     data, length,
 127                                     whole_pdu, pdu_length,
 128                                     sig);
 129 }
 130
 131 static NTSTATUS gensec_spnego_check_packet(struct gensec_security *gensec_security,
 132                                            const uint8_t *data, size_t length,
 133                                            const uint8_t *whole_pdu, size_t pdu_length,
 134                                            const DATA_BLOB *sig)
 135 {
 136         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 137
 138         if (spnego_state->state_position != SPNEGO_DONE
 139             && spnego_state->state_position != SPNEGO_FALLBACK) {
 140                 return NT_STATUS_INVALID_PARAMETER;
 141         }
 142
 143         return gensec_check_packet(spnego_state->sub_sec_security,
 144                                    data, length,
 145                                    whole_pdu, pdu_length,
 146                                    sig);
 147 }
 148
 149 static NTSTATUS gensec_spnego_seal_packet(struct gensec_security *gensec_security,
 150                                           TALLOC_CTX *mem_ctx,
 151                                           uint8_t *data, size_t length,
 152                                           const uint8_t *whole_pdu, size_t pdu_length,
 153                                           DATA_BLOB *sig)
 154 {
 155         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 156
 157         if (spnego_state->state_position != SPNEGO_DONE
 158             && spnego_state->state_position != SPNEGO_FALLBACK) {
 159                 return NT_STATUS_INVALID_PARAMETER;
 160         }
 161
 162         return gensec_seal_packet(spnego_state->sub_sec_security,
 163                                   mem_ctx,
 164                                   data, length,
 165                                   whole_pdu, pdu_length,
 166                                   sig);
 167 }
 168
 169 static NTSTATUS gensec_spnego_sign_packet(struct gensec_security *gensec_security,
 170                                           TALLOC_CTX *mem_ctx,
 171                                           const uint8_t *data, size_t length,
 172                                           const uint8_t *whole_pdu, size_t pdu_length,
 173                                           DATA_BLOB *sig)
 174 {
 175         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 176
 177         if (spnego_state->state_position != SPNEGO_DONE
 178             && spnego_state->state_position != SPNEGO_FALLBACK) {
 179                 return NT_STATUS_INVALID_PARAMETER;
 180         }
 181
 182         return gensec_sign_packet(spnego_state->sub_sec_security,
 183                                   mem_ctx,
 184                                   data, length,
 185                                   whole_pdu, pdu_length,
 186                                   sig);
 187 }
 188
 189 static NTSTATUS gensec_spnego_wrap(struct gensec_security *gensec_security,
 190                                    TALLOC_CTX *mem_ctx,
 191                                    const DATA_BLOB *in,
 192                                    DATA_BLOB *out)
 193 {
 194         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 195
 196         if (spnego_state->state_position != SPNEGO_DONE
 197             && spnego_state->state_position != SPNEGO_FALLBACK) {
 198                 DEBUG(1, ("gensec_spnego_wrap: wrong state for wrap\n"));
 199                 return NT_STATUS_INVALID_PARAMETER;
 200         }
 201
 202         return gensec_wrap(spnego_state->sub_sec_security,
 203                            mem_ctx, in, out);
 204 }
 205
 206 static NTSTATUS gensec_spnego_unwrap(struct gensec_security *gensec_security,
 207                                      TALLOC_CTX *mem_ctx,
 208                                      const DATA_BLOB *in,
 209                                      DATA_BLOB *out)
 210 {
 211         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 212
 213         if (spnego_state->state_position != SPNEGO_DONE
 214             && spnego_state->state_position != SPNEGO_FALLBACK) {
 215                 DEBUG(1, ("gensec_spnego_unwrap: wrong state for unwrap\n"));
 216                 return NT_STATUS_INVALID_PARAMETER;
 217         }
 218
 219         return gensec_unwrap(spnego_state->sub_sec_security,
 220                              mem_ctx, in, out);
 221 }
 222
 223 static NTSTATUS gensec_spnego_wrap_packets(struct gensec_security *gensec_security,
 224                                            TALLOC_CTX *mem_ctx,
 225                                            const DATA_BLOB *in,
 226                                            DATA_BLOB *out,
 227                                            size_t *len_processed)
 228 {
 229         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 230
 231         if (spnego_state->state_position != SPNEGO_DONE
 232             && spnego_state->state_position != SPNEGO_FALLBACK) {
 233                 DEBUG(1, ("gensec_spnego_wrap: wrong state for wrap\n"));
 234                 return NT_STATUS_INVALID_PARAMETER;
 235         }
 236
 237         return gensec_wrap_packets(spnego_state->sub_sec_security,
 238                                    mem_ctx, in, out,
 239                                    len_processed);
 240 }
 241
 242 static NTSTATUS gensec_spnego_packet_full_request(struct gensec_security *gensec_security,
 243                                                 DATA_BLOB blob, size_t *size)
 244 {
 245         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 246
 247         if (spnego_state->state_position != SPNEGO_DONE
 248             && spnego_state->state_position != SPNEGO_FALLBACK) {
 249                 DEBUG(1, ("gensec_spnego_unwrap: wrong state for unwrap\n"));
 250                 return NT_STATUS_INVALID_PARAMETER;
 251         }
 252
 253         return gensec_packet_full_request(spnego_state->sub_sec_security,
 254                                           blob, size);
 255 }
 256
 257 static NTSTATUS gensec_spnego_unwrap_packets(struct gensec_security *gensec_security,
 258                                              TALLOC_CTX *mem_ctx,
 259                                              const DATA_BLOB *in,
 260                                              DATA_BLOB *out,
 261                                              size_t *len_processed)
 262 {
 263         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 264
 265         if (spnego_state->state_position != SPNEGO_DONE
 266             && spnego_state->state_position != SPNEGO_FALLBACK) {
 267                 DEBUG(1, ("gensec_spnego_unwrap: wrong state for unwrap\n"));
 268                 return NT_STATUS_INVALID_PARAMETER;
 269         }
 270
 271         return gensec_unwrap_packets(spnego_state->sub_sec_security,
 272                                      mem_ctx, in, out,
 273                                      len_processed);
 274 }
 275
 276 static size_t gensec_spnego_sig_size(struct gensec_security *gensec_security, size_t data_size)
 277 {
 278         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 279
 280         if (spnego_state->state_position != SPNEGO_DONE
 281             && spnego_state->state_position != SPNEGO_FALLBACK) {
 282                 return 0;
 283         }
 284
 285         return gensec_sig_size(spnego_state->sub_sec_security, data_size);
 286 }
 287
 288 static size_t gensec_spnego_max_input_size(struct gensec_security *gensec_security)
 289 {
 290         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 291
 292         if (spnego_state->state_position != SPNEGO_DONE
 293             && spnego_state->state_position != SPNEGO_FALLBACK) {
 294                 return 0;
 295         }
 296
 297         return gensec_max_input_size(spnego_state->sub_sec_security);
 298 }
 299
 300 static size_t gensec_spnego_max_wrapped_size(struct gensec_security *gensec_security)
 301 {
 302         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 303
 304         if (spnego_state->state_position != SPNEGO_DONE
 305             && spnego_state->state_position != SPNEGO_FALLBACK) {
 306                 return 0;
 307         }
 308
 309         return gensec_max_wrapped_size(spnego_state->sub_sec_security);
 310 }
 311
 312 static NTSTATUS gensec_spnego_session_key(struct gensec_security *gensec_security,
 313                                           TALLOC_CTX *mem_ctx,
 314                                           DATA_BLOB *session_key)
 315 {
 316         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 317         if (!spnego_state->sub_sec_security) {
 318                 return NT_STATUS_INVALID_PARAMETER;
 319         }
 320
 321         return gensec_session_key(spnego_state->sub_sec_security,
 322                                   mem_ctx,
 323                                   session_key);
 324 }
 325
 326 static NTSTATUS gensec_spnego_session_info(struct gensec_security *gensec_security,
 327                                            TALLOC_CTX *mem_ctx,
 328                                            struct auth_session_info **session_info)
 329 {
 330         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 331         if (!spnego_state->sub_sec_security) {
 332                 return NT_STATUS_INVALID_PARAMETER;
 333         }
 334
 335         return gensec_session_info(spnego_state->sub_sec_security,
 336                                    mem_ctx,
 337                                    session_info);
 338 }
 339
 340 /** Fallback to another GENSEC mechanism, based on magic strings
 341  *
 342  * This is the 'fallback' case, where we don't get SPNEGO, and have to
 343  * try all the other options (and hope they all have a magic string
 344  * they check)
 345 */
 346
 347 static NTSTATUS gensec_spnego_server_try_fallback(struct gensec_security *gensec_security,
 348                                                   struct spnego_state *spnego_state,
 349                                                   struct tevent_context *ev,
 350                                                   TALLOC_CTX *out_mem_ctx,
 351                                                   const DATA_BLOB in, DATA_BLOB *out)
 352 {
 353         int i,j;
 354         struct gensec_security_ops **all_ops
 355                 = gensec_security_mechs(gensec_security, out_mem_ctx);
 356         for (i=0; all_ops[i]; i++) {
 357                 bool is_spnego;
 358                 NTSTATUS nt_status;
 359
 360                 if (gensec_security != NULL &&
 361                                 !gensec_security_ops_enabled(all_ops[i], gensec_security))
 362                     continue;
 363
 364                 if (!all_ops[i]->oid) {
 365                         continue;
 366                 }
 367
 368                 is_spnego = false;
 369                 for (j=0; all_ops[i]->oid[j]; j++) {
 370                         if (strcasecmp(GENSEC_OID_SPNEGO,all_ops[i]->oid[j]) == 0) {
 371                                 is_spnego = true;
 372                         }
 373                 }
 374                 if (is_spnego) {
 375                         continue;
 376                 }
 377
 378                 if (!all_ops[i]->magic) {
 379                         continue;
 380                 }
 381
 382                 nt_status = all_ops[i]->magic(gensec_security, &in);
 383                 if (!NT_STATUS_IS_OK(nt_status)) {
 384                         continue;
 385                 }
 386
 387                 spnego_state->state_position = SPNEGO_FALLBACK;
 388
 389                 nt_status = gensec_subcontext_start(spnego_state,
 390                                                     gensec_security,
 391                                                     &spnego_state->sub_sec_security);
 392
 393                 if (!NT_STATUS_IS_OK(nt_status)) {
 394                         return nt_status;
 395                 }
 396                 /* select the sub context */
 397                 nt_status = gensec_start_mech_by_ops(spnego_state->sub_sec_security,
 398                                                      all_ops[i]);
 399                 if (!NT_STATUS_IS_OK(nt_status)) {
 400                         return nt_status;
 401                 }
 402                 nt_status = gensec_update(spnego_state->sub_sec_security,
 403                                           ev, out_mem_ctx, in, out);
 404                 return nt_status;
 405         }
 406         DEBUG(1, ("Failed to parse SPNEGO request\n"));
 407         return NT_STATUS_INVALID_PARAMETER;
 408 }
 409
 410 /*
 411    Parse the netTokenInit, either from the client, to the server, or
 412    from the server to the client.
 413 */
 414
 415 static NTSTATUS gensec_spnego_parse_negTokenInit(struct gensec_security *gensec_security,
 416                                                  struct spnego_state *spnego_state,
 417                                                  TALLOC_CTX *out_mem_ctx,
 418                                                  struct tevent_context *ev,
 419                                                  const char **mechType,
 420                                                  const DATA_BLOB unwrapped_in, DATA_BLOB *unwrapped_out)
 421 {
 422         int i;
 423         NTSTATUS nt_status = NT_STATUS_INVALID_PARAMETER;
 424         DATA_BLOB null_data_blob = data_blob(NULL,0);
 425         bool ok;
 426
 427         const struct gensec_security_ops_wrapper *all_sec
 428                 = gensec_security_by_oid_list(gensec_security,
 429                                               out_mem_ctx,
 430                                               mechType,
 431                                               GENSEC_OID_SPNEGO);
 432
 433         ok = spnego_write_mech_types(spnego_state,
 434                                      mechType,
 435                                      &spnego_state->mech_types);
 436         if (!ok) {
 437                 DEBUG(1, ("SPNEGO: Failed to write mechTypes\n"));
 438                 return NT_STATUS_NO_MEMORY;
 439         }
 440
 441         if (spnego_state->state_position == SPNEGO_SERVER_START) {
 442                 uint32_t j;
 443                 for (j=0; mechType && mechType[j]; j++) {
 444                         for (i=0; all_sec && all_sec[i].op; i++) {
 445                                 if (strcmp(mechType[j], all_sec[i].oid) != 0) {
 446                                         continue;
 447                                 }
 448
 449                                 nt_status = gensec_subcontext_start(spnego_state,
 450                                                                     gensec_security,
 451                                                                     &spnego_state->sub_sec_security);
 452                                 if (!NT_STATUS_IS_OK(nt_status)) {
 453                                         return nt_status;
 454                                 }
 455                                 /* select the sub context */
 456                                 nt_status = gensec_start_mech_by_ops(spnego_state->sub_sec_security,
 457                                                                      all_sec[i].op);
 458                                 if (!NT_STATUS_IS_OK(nt_status)) {
 459                                         talloc_free(spnego_state->sub_sec_security);
 460                                         spnego_state->sub_sec_security = NULL;
 461                                         break;
 462                                 }
 463
 464                                 if (j > 0) {
 465                                         /* no optimistic token */
 466                                         spnego_state->neg_oid = all_sec[i].oid;
 467                                         *unwrapped_out = data_blob_null;
 468                                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 469                                         break;
 470                                 }
 471
 472                                 nt_status = gensec_update(spnego_state->sub_sec_security,
 473                                                           out_mem_ctx,
 474                                                           ev,
 475                                                           unwrapped_in,
 476                                                           unwrapped_out);
 477                                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_PARAMETER) ||
 478                                     NT_STATUS_EQUAL(nt_status, NT_STATUS_CANT_ACCESS_DOMAIN_INFO)) {
 479                                         /* Pretend we never started it (lets the first run find some incompatible demand) */
 480
 481                                         DEBUG(1, ("SPNEGO(%s) NEG_TOKEN_INIT failed to parse contents: %s\n",
 482                                                   spnego_state->sub_sec_security->ops->name, nt_errstr(nt_status)));
 483                                         talloc_free(spnego_state->sub_sec_security);
 484                                         spnego_state->sub_sec_security = NULL;
 485                                         break;
 486                                 }
 487
 488                                 spnego_state->neg_oid = all_sec[i].oid;
 489                                 break;
 490                         }
 491                         if (spnego_state->sub_sec_security) {
 492                                 break;
 493                         }
 494                 }
 495
 496                 if (!spnego_state->sub_sec_security) {
 497                         DEBUG(1, ("SPNEGO: Could not find a suitable mechtype in NEG_TOKEN_INIT\n"));
 498                         return NT_STATUS_INVALID_PARAMETER;
 499                 }
 500         }
 501
 502         /* Having tried any optimistic token from the client (if we
 503          * were the server), if we didn't get anywhere, walk our list
 504          * in our preference order */
 505
 506         if (!spnego_state->sub_sec_security) {
 507                 for (i=0; all_sec && all_sec[i].op; i++) {
 508                         nt_status = gensec_subcontext_start(spnego_state,
 509                                                             gensec_security,
 510                                                             &spnego_state->sub_sec_security);
 511                         if (!NT_STATUS_IS_OK(nt_status)) {
 512                                 return nt_status;
 513                         }
 514                         /* select the sub context */
 515                         nt_status = gensec_start_mech_by_ops(spnego_state->sub_sec_security,
 516                                                              all_sec[i].op);
 517                         if (!NT_STATUS_IS_OK(nt_status)) {
 518                                 talloc_free(spnego_state->sub_sec_security);
 519                                 spnego_state->sub_sec_security = NULL;
 520                                 continue;
 521                         }
 522
 523                         spnego_state->neg_oid = all_sec[i].oid;
 524
 525                         /* only get the helping start blob for the first OID */
 526                         nt_status = gensec_update(spnego_state->sub_sec_security,
 527                                                   out_mem_ctx,
 528                                                   ev,
 529                                                   null_data_blob,
 530                                                   unwrapped_out);
 531
 532                         /* it is likely that a NULL input token will
 533                          * not be liked by most server mechs, but if
 534                          * we are in the client, we want the first
 535                          * update packet to be able to abort the use
 536                          * of this mech */
 537                         if (spnego_state->state_position != SPNEGO_SERVER_START) {
 538                                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_PARAMETER) ||
 539                                     NT_STATUS_EQUAL(nt_status, NT_STATUS_NO_LOGON_SERVERS) ||
 540                                     NT_STATUS_EQUAL(nt_status, NT_STATUS_TIME_DIFFERENCE_AT_DC) ||
 541                                     NT_STATUS_EQUAL(nt_status, NT_STATUS_CANT_ACCESS_DOMAIN_INFO)) {
 542                                         /* Pretend we never started it (lets the first run find some incompatible demand) */
 543
 544                                         DEBUG(3, ("SPNEGO(%s) NEG_TOKEN_INIT failed: %s\n",
 545                                                   spnego_state->sub_sec_security->ops->name, nt_errstr(nt_status)));
 546                                         talloc_free(spnego_state->sub_sec_security);
 547                                         spnego_state->sub_sec_security = NULL;
 548                                         continue;
 549                                 }
 550                         }
 551
 552                         break;
 553                 }
 554         }
 555
 556         if (spnego_state->sub_sec_security) {
 557                 /* it is likely that a NULL input token will
 558                  * not be liked by most server mechs, but this
 559                  * does the right thing in the CIFS client.
 560                  * just push us along the merry-go-round
 561                  * again, and hope for better luck next
 562                  * time */
 563
 564                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_PARAMETER)) {
 565                         *unwrapped_out = data_blob(NULL, 0);
 566                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
 567                 }
 568
 569                 if (!NT_STATUS_EQUAL(nt_status, NT_STATUS_INVALID_PARAMETER)
 570                     && !NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)
 571                     && !NT_STATUS_IS_OK(nt_status)) {
 572                         DEBUG(1, ("SPNEGO(%s) NEG_TOKEN_INIT failed: %s\n",
 573                                   spnego_state->sub_sec_security->ops->name, nt_errstr(nt_status)));
 574                         talloc_free(spnego_state->sub_sec_security);
 575                         spnego_state->sub_sec_security = NULL;
 576
 577                         /* We started the mech correctly, and the
 578                          * input from the other side was valid.
 579                          * Return the error (say bad password, invalid
 580                          * ticket) */
 581                         return nt_status;
 582                 }
 583
 584                 return nt_status; /* OK, INVALID_PARAMETER ore MORE PROCESSING */
 585         }
 586
 587         DEBUG(1, ("SPNEGO: Could not find a suitable mechtype in NEG_TOKEN_INIT\n"));
 588         /* we could re-negotiate here, but it would only work
 589          * if the client or server lied about what it could
 590          * support the first time.  Lets keep this code to
 591          * reality */
 592
 593         return nt_status;
 594 }
 595
 596 /** create a negTokenInit
 597  *
 598  * This is the same packet, no matter if the client or server sends it first, but it is always the first packet
 599 */
 600 static NTSTATUS gensec_spnego_create_negTokenInit(struct gensec_security *gensec_security,
 601                                                   struct spnego_state *spnego_state,
 602                                                   TALLOC_CTX *out_mem_ctx,
 603                                                   struct tevent_context *ev,
 604                                                   const DATA_BLOB in, DATA_BLOB *out)
 605 {
 606         int i;
 607         NTSTATUS nt_status = NT_STATUS_INVALID_PARAMETER;
 608         DATA_BLOB null_data_blob = data_blob(NULL,0);
 609         const char **mechTypes = NULL;
 610         DATA_BLOB unwrapped_out = data_blob(NULL, 0);
 611         const struct gensec_security_ops_wrapper *all_sec;
 612
 613         mechTypes = gensec_security_oids(gensec_security,
 614                                          out_mem_ctx, GENSEC_OID_SPNEGO);
 615
 616         all_sec = gensec_security_by_oid_list(gensec_security,
 617                                               out_mem_ctx,
 618                                               mechTypes,
 619                                               GENSEC_OID_SPNEGO);
 620         for (i=0; all_sec && all_sec[i].op; i++) {
 621                 struct spnego_data spnego_out;
 622                 const char **send_mech_types;
 623                 bool ok;
 624
 625                 nt_status = gensec_subcontext_start(spnego_state,
 626                                                     gensec_security,
 627                                                     &spnego_state->sub_sec_security);
 628                 if (!NT_STATUS_IS_OK(nt_status)) {
 629                         return nt_status;
 630                 }
 631                 /* select the sub context */
 632                 nt_status = gensec_start_mech_by_ops(spnego_state->sub_sec_security,
 633                                                      all_sec[i].op);
 634                 if (!NT_STATUS_IS_OK(nt_status)) {
 635                         talloc_free(spnego_state->sub_sec_security);
 636                         spnego_state->sub_sec_security = NULL;
 637                         continue;
 638                 }
 639
 640                 /* In the client, try and produce the first (optimistic) packet */
 641                 if (spnego_state->state_position == SPNEGO_CLIENT_START) {
 642                         nt_status = gensec_update(spnego_state->sub_sec_security,
 643                                                   out_mem_ctx,
 644                                                   ev,
 645                                                   null_data_blob,
 646                                                   &unwrapped_out);
 647
 648                         if (!NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)
 649                             && !NT_STATUS_IS_OK(nt_status)) {
 650                                 DEBUG(1, ("SPNEGO(%s) creating NEG_TOKEN_INIT failed: %s\n",
 651                                           spnego_state->sub_sec_security->ops->name, nt_errstr(nt_status)));
 652                                 talloc_free(spnego_state->sub_sec_security);
 653                                 spnego_state->sub_sec_security = NULL;
 654                                 /* Pretend we never started it (lets the first run find some incompatible demand) */
 655
 656                                 continue;
 657                         }
 658                 }
 659
 660                 spnego_out.type = SPNEGO_NEG_TOKEN_INIT;
 661
 662                 send_mech_types = gensec_security_oids_from_ops_wrapped(out_mem_ctx,
 663                                                                         &all_sec[i]);
 664
 665                 ok = spnego_write_mech_types(spnego_state,
 666                                              send_mech_types,
 667                                              &spnego_state->mech_types);
 668                 if (!ok) {
 669                         DEBUG(1, ("SPNEGO: Failed to write mechTypes\n"));
 670                         return NT_STATUS_NO_MEMORY;
 671                 }
 672
 673                 /* List the remaining mechs as options */
 674                 spnego_out.negTokenInit.mechTypes = send_mech_types;
 675                 spnego_out.negTokenInit.reqFlags = null_data_blob;
 676                 spnego_out.negTokenInit.reqFlagsPadding = 0;
 677
 678                 if (spnego_state->state_position == SPNEGO_SERVER_START) {
 679                         spnego_out.negTokenInit.mechListMIC
 680                                 = data_blob_string_const(ADS_IGNORE_PRINCIPAL);
 681                 } else {
 682                         spnego_out.negTokenInit.mechListMIC = null_data_blob;
 683                 }
 684
 685                 spnego_out.negTokenInit.mechToken = unwrapped_out;
 686
 687                 if (spnego_write_data(out_mem_ctx, out, &spnego_out) == -1) {
 688                         DEBUG(1, ("Failed to write NEG_TOKEN_INIT\n"));
 689                                 return NT_STATUS_INVALID_PARAMETER;
 690                 }
 691
 692                 /* set next state */
 693                 spnego_state->neg_oid = all_sec[i].oid;
 694
 695                 if (NT_STATUS_IS_OK(nt_status)) {
 696                         spnego_state->no_response_expected = true;
 697                 }
 698
 699                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 700         }
 701         talloc_free(spnego_state->sub_sec_security);
 702         spnego_state->sub_sec_security = NULL;
 703
 704         DEBUG(1, ("Failed to setup SPNEGO negTokenInit request: %s\n", nt_errstr(nt_status)));
 705         return NT_STATUS_INVALID_PARAMETER;
 706 }
 707
 708
 709 /** create a server negTokenTarg
 710  *
 711  * This is the case, where the client is the first one who sends data
 712 */
 713
 714 static NTSTATUS gensec_spnego_server_negTokenTarg(struct spnego_state *spnego_state,
 715                                                   TALLOC_CTX *out_mem_ctx,
 716                                                   NTSTATUS nt_status,
 717                                                   const DATA_BLOB unwrapped_out,
 718                                                   DATA_BLOB mech_list_mic,
 719                                                   DATA_BLOB *out)
 720 {
 721         struct spnego_data spnego_out;
 722         DATA_BLOB null_data_blob = data_blob(NULL, 0);
 723
 724         /* compose reply */
 725         spnego_out.type = SPNEGO_NEG_TOKEN_TARG;
 726         spnego_out.negTokenTarg.responseToken = unwrapped_out;
 727         spnego_out.negTokenTarg.mechListMIC = null_data_blob;
 728         spnego_out.negTokenTarg.supportedMech = NULL;
 729
 730         if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 731                 spnego_out.negTokenTarg.supportedMech = spnego_state->neg_oid;
 732                 spnego_out.negTokenTarg.negResult = SPNEGO_ACCEPT_INCOMPLETE;
 733                 spnego_state->state_position = SPNEGO_SERVER_TARG;
 734         } else if (NT_STATUS_IS_OK(nt_status)) {
 735                 if (unwrapped_out.data) {
 736                         spnego_out.negTokenTarg.supportedMech = spnego_state->neg_oid;
 737                 }
 738                 spnego_out.negTokenTarg.negResult = SPNEGO_ACCEPT_COMPLETED;
 739                 spnego_out.negTokenTarg.mechListMIC = mech_list_mic;
 740                 spnego_state->state_position = SPNEGO_DONE;
 741         } else {
 742                 spnego_out.negTokenTarg.negResult = SPNEGO_REJECT;
 743                 DEBUG(2, ("SPNEGO login failed: %s\n", nt_errstr(nt_status)));
 744                 spnego_state->state_position = SPNEGO_DONE;
 745         }
 746
 747         if (spnego_write_data(out_mem_ctx, out, &spnego_out) == -1) {
 748                 DEBUG(1, ("Failed to write SPNEGO reply to NEG_TOKEN_TARG\n"));
 749                 return NT_STATUS_INVALID_PARAMETER;
 750         }
 751
 752         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_TARG;
 753
 754         return nt_status;
 755 }
 756
 757
 758 static NTSTATUS gensec_spnego_update(struct gensec_security *gensec_security, TALLOC_CTX *out_mem_ctx,
 759                                      struct tevent_context *ev,
 760                                      const DATA_BLOB in, DATA_BLOB *out)
 761 {
 762         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
 763         DATA_BLOB null_data_blob = data_blob(NULL, 0);
 764         DATA_BLOB mech_list_mic = data_blob(NULL, 0);
 765         DATA_BLOB unwrapped_out = data_blob(NULL, 0);
 766         struct spnego_data spnego_out;
 767         struct spnego_data spnego;
 768
 769         ssize_t len;
 770
 771         *out = data_blob(NULL, 0);
 772
 773         if (!out_mem_ctx) {
 774                 out_mem_ctx = spnego_state;
 775         }
 776
 777         /* and switch into the state machine */
 778
 779         switch (spnego_state->state_position) {
 780         case SPNEGO_FALLBACK:
 781                 return gensec_update(spnego_state->sub_sec_security, ev,
 782                                      out_mem_ctx, in, out);
 783         case SPNEGO_SERVER_START:
 784         {
 785                 NTSTATUS nt_status;
 786                 if (in.length) {
 787
 788                         len = spnego_read_data(gensec_security, in, &spnego);
 789                         if (len == -1) {
 790                                 return gensec_spnego_server_try_fallback(gensec_security, spnego_state,
 791                                                                          out_mem_ctx, ev, in, out);
 792                         }
 793                         /* client sent NegTargetInit, we send NegTokenTarg */
 794
 795                         /* OK, so it's real SPNEGO, check the packet's the one we expect */
 796                         if (spnego.type != spnego_state->expected_packet) {
 797                                 DEBUG(1, ("Invalid SPNEGO request: %d, expected %d\n", spnego.type,
 798                                           spnego_state->expected_packet));
 799                                 dump_data(1, in.data, in.length);
 800                                 spnego_free_data(&spnego);
 801                                 return NT_STATUS_INVALID_PARAMETER;
 802                         }
 803
 804                         nt_status = gensec_spnego_parse_negTokenInit(gensec_security,
 805                                                                      spnego_state,
 806                                                                      out_mem_ctx,
 807                                                                      ev,
 808                                                                      spnego.negTokenInit.mechTypes,
 809                                                                      spnego.negTokenInit.mechToken,
 810                                                                      &unwrapped_out);
 811
 812                         nt_status = gensec_spnego_server_negTokenTarg(spnego_state,
 813                                                                       out_mem_ctx,
 814                                                                       nt_status,
 815                                                                       unwrapped_out,
 816                                                                       null_data_blob,
 817                                                                       out);
 818
 819                         spnego_free_data(&spnego);
 820
 821                         return nt_status;
 822                 } else {
 823                         nt_status = gensec_spnego_create_negTokenInit(gensec_security, spnego_state,
 824                                                                       out_mem_ctx, ev, in, out);
 825                         spnego_state->state_position = SPNEGO_SERVER_START;
 826                         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_INIT;
 827                         return nt_status;
 828                 }
 829         }
 830
 831         case SPNEGO_CLIENT_START:
 832         {
 833                 /* The server offers a list of mechanisms */
 834
 835                 const char *my_mechs[] = {NULL, NULL};
 836                 NTSTATUS nt_status = NT_STATUS_INVALID_PARAMETER;
 837
 838                 if (!in.length) {
 839                         /* client to produce negTokenInit */
 840                         nt_status = gensec_spnego_create_negTokenInit(gensec_security, spnego_state,
 841                                                                       out_mem_ctx, ev, in, out);
 842                         spnego_state->state_position = SPNEGO_CLIENT_TARG;
 843                         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_TARG;
 844                         return nt_status;
 845                 }
 846
 847                 len = spnego_read_data(gensec_security, in, &spnego);
 848
 849                 if (len == -1) {
 850                         DEBUG(1, ("Invalid SPNEGO request:\n"));
 851                         dump_data(1, in.data, in.length);
 852                         return NT_STATUS_INVALID_PARAMETER;
 853                 }
 854
 855                 /* OK, so it's real SPNEGO, check the packet's the one we expect */
 856                 if (spnego.type != spnego_state->expected_packet) {
 857                         DEBUG(1, ("Invalid SPNEGO request: %d, expected %d\n", spnego.type,
 858                                   spnego_state->expected_packet));
 859                         dump_data(1, in.data, in.length);
 860                         spnego_free_data(&spnego);
 861                         return NT_STATUS_INVALID_PARAMETER;
 862                 }
 863
 864                 if (spnego.negTokenInit.targetPrincipal
 865                     && strcmp(spnego.negTokenInit.targetPrincipal, ADS_IGNORE_PRINCIPAL) != 0) {
 866                         DEBUG(5, ("Server claims it's principal name is %s\n", spnego.negTokenInit.targetPrincipal));
 867                         if (lpcfg_client_use_spnego_principal(gensec_security->settings->lp_ctx)) {
 868                                 gensec_set_target_principal(gensec_security, spnego.negTokenInit.targetPrincipal);
 869                         }
 870                 }
 871
 872                 nt_status = gensec_spnego_parse_negTokenInit(gensec_security,
 873                                                              spnego_state,
 874                                                              out_mem_ctx,
 875                                                              ev,
 876                                                              spnego.negTokenInit.mechTypes,
 877                                                              spnego.negTokenInit.mechToken,
 878                                                              &unwrapped_out);
 879
 880                 if (!NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED) && !NT_STATUS_IS_OK(nt_status)) {
 881                         spnego_free_data(&spnego);
 882                         return nt_status;
 883                 }
 884
 885                 my_mechs[0] = spnego_state->neg_oid;
 886                 /* compose reply */
 887                 spnego_out.type = SPNEGO_NEG_TOKEN_INIT;
 888                 spnego_out.negTokenInit.mechTypes = my_mechs;
 889                 spnego_out.negTokenInit.reqFlags = null_data_blob;
 890                 spnego_out.negTokenInit.reqFlagsPadding = 0;
 891                 spnego_out.negTokenInit.mechListMIC = null_data_blob;
 892                 spnego_out.negTokenInit.mechToken = unwrapped_out;
 893
 894                 if (spnego_write_data(out_mem_ctx, out, &spnego_out) == -1) {
 895                         DEBUG(1, ("Failed to write SPNEGO reply to NEG_TOKEN_INIT\n"));
 896                                 return NT_STATUS_INVALID_PARAMETER;
 897                 }
 898
 899                 /* set next state */
 900                 spnego_state->expected_packet = SPNEGO_NEG_TOKEN_TARG;
 901                 spnego_state->state_position = SPNEGO_CLIENT_TARG;
 902
 903                 if (NT_STATUS_IS_OK(nt_status)) {
 904                         spnego_state->no_response_expected = true;
 905                 }
 906
 907                 spnego_free_data(&spnego);
 908                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 909         }
 910         case SPNEGO_SERVER_TARG:
 911         {
 912                 NTSTATUS nt_status;
 913                 bool new_spnego = false;
 914
 915                 if (!in.length) {
 916                         return NT_STATUS_INVALID_PARAMETER;
 917                 }
 918
 919                 len = spnego_read_data(gensec_security, in, &spnego);
 920
 921                 if (len == -1) {
 922                         DEBUG(1, ("Invalid SPNEGO request:\n"));
 923                         dump_data(1, in.data, in.length);
 924                         return NT_STATUS_INVALID_PARAMETER;
 925                 }
 926
 927                 /* OK, so it's real SPNEGO, check the packet's the one we expect */
 928                 if (spnego.type != spnego_state->expected_packet) {
 929                         DEBUG(1, ("Invalid SPNEGO request: %d, expected %d\n", spnego.type,
 930                                   spnego_state->expected_packet));
 931                         dump_data(1, in.data, in.length);
 932                         spnego_free_data(&spnego);
 933                         return NT_STATUS_INVALID_PARAMETER;
 934                 }
 935
 936                 if (!spnego_state->sub_sec_security) {
 937                         DEBUG(1, ("SPNEGO: Did not setup a mech in NEG_TOKEN_INIT\n"));
 938                         spnego_free_data(&spnego);
 939                         return NT_STATUS_INVALID_PARAMETER;
 940                 }
 941
 942                 nt_status = gensec_update(spnego_state->sub_sec_security,
 943                                           out_mem_ctx, ev,
 944                                           spnego.negTokenTarg.responseToken,
 945                                           &unwrapped_out);
 946                 if (NT_STATUS_IS_OK(nt_status) && spnego.negTokenTarg.mechListMIC.length > 0) {
 947                         new_spnego = true;
 948                         nt_status = gensec_check_packet(spnego_state->sub_sec_security,
 949                                                         spnego_state->mech_types.data,
 950                                                         spnego_state->mech_types.length,
 951                                                         spnego_state->mech_types.data,
 952                                                         spnego_state->mech_types.length,
 953                                                         &spnego.negTokenTarg.mechListMIC);
 954                         if (!NT_STATUS_IS_OK(nt_status)) {
 955                                 DEBUG(2,("GENSEC SPNEGO: failed to verify mechListMIC: %s\n",
 956                                         nt_errstr(nt_status)));
 957                         }
 958                 }
 959                 if (NT_STATUS_IS_OK(nt_status) && new_spnego) {
 960                         nt_status = gensec_sign_packet(spnego_state->sub_sec_security,
 961                                                        out_mem_ctx,
 962                                                        spnego_state->mech_types.data,
 963                                                        spnego_state->mech_types.length,
 964                                                        spnego_state->mech_types.data,
 965                                                        spnego_state->mech_types.length,
 966                                                        &mech_list_mic);
 967                         if (!NT_STATUS_IS_OK(nt_status)) {
 968                                 DEBUG(2,("GENSEC SPNEGO: failed to sign mechListMIC: %s\n",
 969                                         nt_errstr(nt_status)));
 970                         }
 971                 }
 972
 973                 nt_status = gensec_spnego_server_negTokenTarg(spnego_state,
 974                                                               out_mem_ctx,
 975                                                               nt_status,
 976                                                               unwrapped_out,
 977                                                               mech_list_mic,
 978                                                               out);
 979
 980                 spnego_free_data(&spnego);
 981
 982                 return nt_status;
 983         }
 984         case SPNEGO_CLIENT_TARG:
 985         {
 986                 NTSTATUS nt_status;
 987                 if (!in.length) {
 988                         return NT_STATUS_INVALID_PARAMETER;
 989                 }
 990
 991                 len = spnego_read_data(gensec_security, in, &spnego);
 992
 993                 if (len == -1) {
 994                         DEBUG(1, ("Invalid SPNEGO request:\n"));
 995                         dump_data(1, in.data, in.length);
 996                         return NT_STATUS_INVALID_PARAMETER;
 997                 }
 998
 999                 /* OK, so it's real SPNEGO, check the packet's the one we expect */
1000                 if (spnego.type != spnego_state->expected_packet) {
1001                         DEBUG(1, ("Invalid SPNEGO request: %d, expected %d\n", spnego.type,
1002                                   spnego_state->expected_packet));
1003                         dump_data(1, in.data, in.length);
1004                         spnego_free_data(&spnego);
1005                         return NT_STATUS_INVALID_PARAMETER;
1006                 }
1007
1008                 if (spnego.negTokenTarg.negResult == SPNEGO_REJECT) {
1009                         spnego_free_data(&spnego);
1010                         return NT_STATUS_ACCESS_DENIED;
1011                 }
1012
1013                 /* Server didn't like our choice of mech, and chose something else */
1014                 if ((spnego.negTokenTarg.negResult == SPNEGO_ACCEPT_INCOMPLETE) &&
1015                     spnego.negTokenTarg.supportedMech &&
1016                     strcmp(spnego.negTokenTarg.supportedMech, spnego_state->neg_oid) != 0) {
1017                         DEBUG(3,("GENSEC SPNEGO: client preferred mech (%s) not accepted, server wants: %s\n",
1018                                  gensec_get_name_by_oid(gensec_security, spnego.negTokenTarg.supportedMech),
1019                                  gensec_get_name_by_oid(gensec_security, spnego_state->neg_oid)));
1020
1021                         talloc_free(spnego_state->sub_sec_security);
1022                         nt_status = gensec_subcontext_start(spnego_state,
1023                                                             gensec_security,
1024                                                             &spnego_state->sub_sec_security);
1025                         if (!NT_STATUS_IS_OK(nt_status)) {
1026                                 spnego_free_data(&spnego);
1027                                 return nt_status;
1028                         }
1029                         /* select the sub context */
1030                         nt_status = gensec_start_mech_by_oid(spnego_state->sub_sec_security,
1031                                                              spnego.negTokenTarg.supportedMech);
1032                         if (!NT_STATUS_IS_OK(nt_status)) {
1033                                 spnego_free_data(&spnego);
1034                                 return nt_status;
1035                         }
1036
1037                         nt_status = gensec_update(spnego_state->sub_sec_security,
1038                                                   out_mem_ctx, ev,
1039                                                   spnego.negTokenTarg.responseToken,
1040                                                   &unwrapped_out);
1041                         spnego_state->neg_oid = talloc_strdup(spnego_state, spnego.negTokenTarg.supportedMech);
1042                 } else if (spnego_state->no_response_expected) {
1043                         if (spnego.negTokenTarg.negResult != SPNEGO_ACCEPT_COMPLETED) {
1044                                 DEBUG(3,("GENSEC SPNEGO: client GENSEC accepted, but server rejected (bad password?)\n"));
1045                                 nt_status = NT_STATUS_INVALID_PARAMETER;
1046                         } else if (spnego.negTokenTarg.responseToken.length) {
1047                                 DEBUG(2,("GENSEC SPNEGO: client GENSEC accepted, but server continued negotiation!\n"));
1048                                 nt_status = NT_STATUS_INVALID_PARAMETER;
1049                         } else {
1050                                 nt_status = NT_STATUS_OK;
1051                         }
1052                         if (NT_STATUS_IS_OK(nt_status) && spnego.negTokenTarg.mechListMIC.length > 0) {
1053                                 nt_status = gensec_check_packet(spnego_state->sub_sec_security,
1054                                                                 spnego_state->mech_types.data,
1055                                                                 spnego_state->mech_types.length,
1056                                                                 spnego_state->mech_types.data,
1057                                                                 spnego_state->mech_types.length,
1058                                                                 &spnego.negTokenTarg.mechListMIC);
1059                                 if (!NT_STATUS_IS_OK(nt_status)) {
1060                                         DEBUG(2,("GENSEC SPNEGO: failed to verify mechListMIC: %s\n",
1061                                                 nt_errstr(nt_status)));
1062                                 }
1063                         }
1064                 } else {
1065                         bool new_spnego = false;
1066
1067                         nt_status = gensec_update(spnego_state->sub_sec_security,
1068                                                   out_mem_ctx, ev,
1069                                                   spnego.negTokenTarg.responseToken,
1070                                                   &unwrapped_out);
1071
1072                         if (NT_STATUS_IS_OK(nt_status)
1073                             && spnego.negTokenTarg.negResult != SPNEGO_ACCEPT_COMPLETED) {
1074                                 new_spnego = gensec_have_feature(spnego_state->sub_sec_security,
1075                                                                  GENSEC_FEATURE_NEW_SPNEGO);
1076                         }
1077                         if (NT_STATUS_IS_OK(nt_status) && new_spnego) {
1078                                 nt_status = gensec_sign_packet(spnego_state->sub_sec_security,
1079                                                                out_mem_ctx,
1080                                                                spnego_state->mech_types.data,
1081                                                                spnego_state->mech_types.length,
1082                                                                spnego_state->mech_types.data,
1083                                                                spnego_state->mech_types.length,
1084                                                                &mech_list_mic);
1085                                 if (!NT_STATUS_IS_OK(nt_status)) {
1086                                         DEBUG(2,("GENSEC SPNEGO: failed to sign mechListMIC: %s\n",
1087                                                 nt_errstr(nt_status)));
1088                                 }
1089                         }
1090                         if (NT_STATUS_IS_OK(nt_status)) {
1091                                 spnego_state->no_response_expected = true;
1092                         }
1093                 }
1094
1095                 spnego_free_data(&spnego);
1096
1097                 if (!NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)
1098                         && !NT_STATUS_IS_OK(nt_status)) {
1099                         DEBUG(1, ("SPNEGO(%s) login failed: %s\n",
1100                                   spnego_state->sub_sec_security->ops->name,
1101                                   nt_errstr(nt_status)));
1102                         return nt_status;
1103                 }
1104
1105                 if (unwrapped_out.length || mech_list_mic.length) {
1106                         /* compose reply */
1107                         spnego_out.type = SPNEGO_NEG_TOKEN_TARG;
1108                         spnego_out.negTokenTarg.negResult = SPNEGO_NONE_RESULT;
1109                         spnego_out.negTokenTarg.supportedMech = NULL;
1110                         spnego_out.negTokenTarg.responseToken = unwrapped_out;
1111                         spnego_out.negTokenTarg.mechListMIC = mech_list_mic;
1112
1113                         if (spnego_write_data(out_mem_ctx, out, &spnego_out) == -1) {
1114                                 DEBUG(1, ("Failed to write SPNEGO reply to NEG_TOKEN_TARG\n"));
1115                                 return NT_STATUS_INVALID_PARAMETER;
1116                         }
1117
1118                         spnego_state->state_position = SPNEGO_CLIENT_TARG;
1119                         nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
1120                 } else {
1121
1122                         /* all done - server has accepted, and we agree */
1123                         *out = null_data_blob;
1124
1125                         if (spnego.negTokenTarg.negResult != SPNEGO_ACCEPT_COMPLETED) {
1126                                 /* unless of course it did not accept */
1127                                 DEBUG(1,("gensec_update ok but not accepted\n"));
1128                                 nt_status = NT_STATUS_INVALID_PARAMETER;
1129                         }
1130
1131                         spnego_state->state_position = SPNEGO_DONE;
1132                 }
1133
1134                 return nt_status;
1135         }
1136         case SPNEGO_DONE:
1137                 /* We should not be called after we are 'done' */
1138                 return NT_STATUS_INVALID_PARAMETER;
1139         }
1140         return NT_STATUS_INVALID_PARAMETER;
1141 }
1142
1143 static NTSTATUS gensec_spnego_update_in(struct gensec_security *gensec_security,
1144                                         const DATA_BLOB in, DATA_BLOB *full_in)
1145 {
1146         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
1147         size_t expected;
1148         NTSTATUS status;
1149         bool ok;
1150
1151         *full_in = data_blob_null;
1152
1153         if (spnego_state->in_needed == 0) {
1154                 size_t size = 0;
1155
1156                 /*
1157                  * try to work out the size of the full
1158                  * input token, it might be fragmented
1159                  */
1160                 status = asn1_peek_full_tag(in,  ASN1_APPLICATION(0), &size);
1161                 if (!NT_STATUS_IS_OK(status) &&
1162                     !NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
1163                         status = asn1_peek_full_tag(in, ASN1_CONTEXT(1), &size);
1164                 }
1165
1166                 if (NT_STATUS_IS_OK(status) ||
1167                     NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
1168                         spnego_state->in_needed = size;
1169                 } else {
1170                         /*
1171                          * If it is not an asn1 message
1172                          * just call the next layer.
1173                          */
1174                         spnego_state->in_needed = in.length;
1175                 }
1176         }
1177
1178         if (spnego_state->in_needed > UINT16_MAX) {
1179                 /*
1180                  * limit the incoming message to 0xFFFF
1181                  * to avoid DoS attacks.
1182                  */
1183                 return NT_STATUS_INVALID_BUFFER_SIZE;
1184         }
1185
1186         if ((spnego_state->in_needed > 0) && (in.length == 0)) {
1187                 /*
1188                  * If we reach this, we know we got at least
1189                  * part of an asn1 message, getting 0 means
1190                  * the remote peer wants us to spin.
1191                  */
1192                 return NT_STATUS_INVALID_PARAMETER;
1193         }
1194
1195         expected = spnego_state->in_needed - spnego_state->in_frag.length;
1196         if (in.length > expected) {
1197                 /*
1198                  * we got more than expected
1199                  */
1200                 return NT_STATUS_INVALID_PARAMETER;
1201         }
1202
1203         if (in.length == spnego_state->in_needed) {
1204                 /*
1205                  * if the in.length contains the full blob
1206                  * we are done.
1207                  *
1208                  * Note: this implies spnego_state->in_frag.length == 0,
1209                  *       but we do not need to check this explicitly
1210                  *       because we already know that we did not get
1211                  *       more than expected.
1212                  */
1213                 *full_in = in;
1214                 return NT_STATUS_OK;
1215         }
1216
1217         ok = data_blob_append(spnego_state, &spnego_state->in_frag,
1218                               in.data, in.length);
1219         if (!ok) {
1220                 return NT_STATUS_NO_MEMORY;
1221         }
1222
1223         if (spnego_state->in_needed > spnego_state->in_frag.length) {
1224                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
1225         }
1226
1227         *full_in = spnego_state->in_frag;
1228         return NT_STATUS_OK;
1229 }
1230
1231 static NTSTATUS gensec_spnego_update_out(struct gensec_security *gensec_security,
1232                                          TALLOC_CTX *out_mem_ctx,
1233                                          DATA_BLOB *_out)
1234 {
1235         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
1236         DATA_BLOB out = data_blob_null;
1237
1238         *_out = data_blob_null;
1239
1240         if (spnego_state->out_frag.length == 0) {
1241                 return spnego_state->out_status;
1242         }
1243
1244         /*
1245          * There is still more data to be delivered
1246          * to the remote peer.
1247          */
1248
1249         if (spnego_state->out_frag.length <= spnego_state->out_max_length) {
1250                 /*
1251                  * Fast path, we can deliver everything
1252                  */
1253
1254                 *_out = spnego_state->out_frag;
1255                 talloc_steal(out_mem_ctx, _out->data);
1256                 spnego_state->out_frag = data_blob_null;
1257                 return spnego_state->out_status;
1258         }
1259
1260         out = spnego_state->out_frag;
1261
1262         /*
1263          * copy the remaining bytes
1264          */
1265         spnego_state->out_frag = data_blob_talloc(spnego_state,
1266                                         out.data + spnego_state->out_max_length,
1267                                         out.length - spnego_state->out_max_length);
1268         if (spnego_state->out_frag.data == NULL) {
1269                 return NT_STATUS_NO_MEMORY;
1270         }
1271
1272         /*
1273          * truncate the buffer
1274          */
1275         data_blob_realloc(spnego_state, &out, spnego_state->out_max_length);
1276
1277         talloc_steal(out_mem_ctx, out.data);
1278         *_out = out;
1279         return NT_STATUS_MORE_PROCESSING_REQUIRED;
1280 }
1281
1282 static NTSTATUS gensec_spnego_update_wrapper(struct gensec_security *gensec_security,
1283                                              TALLOC_CTX *out_mem_ctx,
1284                                              struct tevent_context *ev,
1285                                              const DATA_BLOB in, DATA_BLOB *out)
1286 {
1287         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
1288         DATA_BLOB full_in = data_blob_null;
1289         NTSTATUS status;
1290
1291         *out = data_blob_null;
1292
1293         if (spnego_state->out_frag.length > 0) {
1294                 if (in.length > 0) {
1295                         return NT_STATUS_INVALID_PARAMETER;
1296                 }
1297
1298                 return gensec_spnego_update_out(gensec_security,
1299                                                 out_mem_ctx,
1300                                                 out);
1301         }
1302
1303         status = gensec_spnego_update_in(gensec_security,
1304                                          in, &full_in);
1305         if (!NT_STATUS_IS_OK(status)) {
1306                 return status;
1307         }
1308
1309         status = gensec_spnego_update(gensec_security,
1310                                       spnego_state, ev,
1311                                       full_in,
1312                                       &spnego_state->out_frag);
1313         data_blob_free(&spnego_state->in_frag);
1314         spnego_state->in_needed = 0;
1315         if (!NT_STATUS_IS_OK(status) &&
1316             !NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
1317                 return status;
1318         }
1319
1320         spnego_state->out_status = status;
1321
1322         return gensec_spnego_update_out(gensec_security,
1323                                         out_mem_ctx,
1324                                         out);
1325 }
1326
1327 static void gensec_spnego_want_feature(struct gensec_security *gensec_security,
1328                                        uint32_t feature)
1329 {
1330         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
1331
1332         if (!spnego_state || !spnego_state->sub_sec_security) {
1333                 gensec_security->want_features |= feature;
1334                 return;
1335         }
1336
1337         gensec_want_feature(spnego_state->sub_sec_security,
1338                             feature);
1339 }
1340
1341 static bool gensec_spnego_have_feature(struct gensec_security *gensec_security,
1342                                        uint32_t feature)
1343 {
1344         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
1345         if (!spnego_state->sub_sec_security) {
1346                 return false;
1347         }
1348
1349         return gensec_have_feature(spnego_state->sub_sec_security,
1350                                    feature);
1351 }
1352
1353 static NTTIME gensec_spnego_expire_time(struct gensec_security *gensec_security)
1354 {
1355         struct spnego_state *spnego_state = (struct spnego_state *)gensec_security->private_data;
1356
1357         if (!spnego_state->sub_sec_security) {
1358                 return GENSEC_EXPIRE_TIME_INFINITY;
1359         }
1360
1361         return gensec_expire_time(spnego_state->sub_sec_security);
1362 }
1363
1364 static const char *gensec_spnego_oids[] = {
1365         GENSEC_OID_SPNEGO,
1366         NULL
1367 };
1368
1369 static const struct gensec_security_ops gensec_spnego_security_ops = {
1370         .name             = "spnego",
1371         .sasl_name        = "GSS-SPNEGO",
1372         .auth_type        = DCERPC_AUTH_TYPE_SPNEGO,
1373         .oid              = gensec_spnego_oids,
1374         .client_start     = gensec_spnego_client_start,
1375         .server_start     = gensec_spnego_server_start,
1376         .update           = gensec_spnego_update_wrapper,
1377         .seal_packet      = gensec_spnego_seal_packet,
1378         .sign_packet      = gensec_spnego_sign_packet,
1379         .sig_size         = gensec_spnego_sig_size,
1380         .max_wrapped_size = gensec_spnego_max_wrapped_size,
1381         .max_input_size   = gensec_spnego_max_input_size,
1382         .check_packet     = gensec_spnego_check_packet,
1383         .unseal_packet    = gensec_spnego_unseal_packet,
1384         .packet_full_request = gensec_spnego_packet_full_request,
1385         .wrap             = gensec_spnego_wrap,
1386         .unwrap           = gensec_spnego_unwrap,
1387         .wrap_packets     = gensec_spnego_wrap_packets,
1388         .unwrap_packets   = gensec_spnego_unwrap_packets,
1389         .session_key      = gensec_spnego_session_key,
1390         .session_info     = gensec_spnego_session_info,
1391         .want_feature     = gensec_spnego_want_feature,
1392         .have_feature     = gensec_spnego_have_feature,
1393         .expire_time      = gensec_spnego_expire_time,
1394         .enabled          = true,
1395         .priority         = GENSEC_SPNEGO
1396 };
1397
1398 _PUBLIC_ NTSTATUS gensec_spnego_init(void)
1399 {
1400         NTSTATUS ret;
1401         ret = gensec_register(&gensec_spnego_security_ops);
1402         if (!NT_STATUS_IS_OK(ret)) {
1403                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1404                         gensec_spnego_security_ops.name));
1405                 return ret;
1406         }
1407
1408         return ret;
1409 }