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