source4/libcli/auth/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
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23 */
  24
  25 #include "includes.h"
  26
  27 #undef DBGC_CLASS
  28 #define DBGC_CLASS DBGC_AUTH
  29
  30 enum spnego_state_position {
  31         SPNEGO_SERVER_START,
  32         SPNEGO_CLIENT_START,
  33         SPNEGO_TARG,
  34         SPNEGO_FALLBACK,
  35         SPNEGO_DONE
  36 };
  37
  38 struct spnego_state {
  39         TALLOC_CTX *mem_ctx;
  40         uint_t ref_count;
  41         enum spnego_message_type expected_packet;
  42         enum spnego_message_type state_position;
  43         enum spnego_negResult result;
  44         struct gensec_security *sub_sec_security;
  45 };
  46
  47 static NTSTATUS gensec_spnego_client_start(struct gensec_security *gensec_security)
  48 {
  49         struct spnego_state *spnego_state;
  50         TALLOC_CTX *mem_ctx = talloc_init("gensec_spengo_client_start");
  51         if (!mem_ctx) {
  52                 return NT_STATUS_NO_MEMORY;
  53         }
  54         spnego_state = talloc_p(mem_ctx, struct spnego_state);
  55
  56         if (!spnego_state) {
  57                 return NT_STATUS_NO_MEMORY;
  58         }
  59
  60         spnego_state->expected_packet = SPNEGO_NEG_TOKEN_INIT;
  61         spnego_state->state_position = SPNEGO_CLIENT_START;
  62         spnego_state->result = SPNEGO_ACCEPT_INCOMPLETE;
  63         spnego_state->mem_ctx = mem_ctx;
  64         spnego_state->sub_sec_security = NULL;
  65
  66         gensec_security->private_data = spnego_state;
  67         return NT_STATUS_OK;
  68 }
  69
  70 /*
  71   wrappers for the spnego_*() functions
  72 */
  73 static NTSTATUS gensec_spnego_unseal_packet(struct gensec_security *gensec_security,
  74                                      TALLOC_CTX *mem_ctx,
  75                                      uint8_t *data, size_t length, DATA_BLOB *sig)
  76 {
  77         struct spnego_state *spnego_state = gensec_security->private_data;
  78
  79         if (spnego_state->state_position != SPNEGO_DONE
  80             && spnego_state->state_position != SPNEGO_FALLBACK) {
  81                 return NT_STATUS_INVALID_PARAMETER;
  82         }
  83
  84         return gensec_unseal_packet(spnego_state->sub_sec_security,
  85                                     mem_ctx, data, length, sig);
  86 }
  87
  88 static NTSTATUS gensec_spnego_check_packet(struct gensec_security *gensec_security,
  89                                      TALLOC_CTX *mem_ctx,
  90                                      const uint8_t *data, size_t length,
  91                                      const DATA_BLOB *sig)
  92 {
  93         struct spnego_state *spnego_state = gensec_security->private_data;
  94
  95         return NT_STATUS_NOT_IMPLEMENTED;
  96         if (spnego_state->state_position != SPNEGO_DONE
  97             && spnego_state->state_position != SPNEGO_FALLBACK) {
  98                 return NT_STATUS_INVALID_PARAMETER;
  99         }
 100
 101         return gensec_check_packet(spnego_state->sub_sec_security,
 102                                 mem_ctx, data, length, sig);
 103 }
 104
 105 static NTSTATUS gensec_spnego_seal_packet(struct gensec_security *gensec_security,
 106                                     TALLOC_CTX *mem_ctx,
 107                                     uint8_t *data, size_t length,
 108                                     DATA_BLOB *sig)
 109 {
 110         struct spnego_state *spnego_state = gensec_security->private_data;
 111
 112         return NT_STATUS_NOT_IMPLEMENTED;
 113         if (spnego_state->state_position != SPNEGO_DONE
 114             && spnego_state->state_position != SPNEGO_FALLBACK) {
 115                 return NT_STATUS_INVALID_PARAMETER;
 116         }
 117
 118         return gensec_seal_packet(spnego_state->sub_sec_security,
 119                                   mem_ctx, data, length, sig);
 120 }
 121
 122 static NTSTATUS gensec_spnego_sign_packet(struct gensec_security *gensec_security,
 123                                     TALLOC_CTX *mem_ctx,
 124                                     const uint8_t *data, size_t length,
 125                                     DATA_BLOB *sig)
 126 {
 127         struct spnego_state *spnego_state = gensec_security->private_data;
 128
 129         if (spnego_state->state_position != SPNEGO_DONE
 130             && spnego_state->state_position != SPNEGO_FALLBACK) {
 131                 return NT_STATUS_INVALID_PARAMETER;
 132         }
 133
 134         return gensec_sign_packet(spnego_state->sub_sec_security,
 135                                   mem_ctx, data, length, sig);
 136 }
 137
 138 static NTSTATUS gensec_spnego_session_key(struct gensec_security *gensec_security,
 139                                     DATA_BLOB *session_key)
 140 {
 141         struct spnego_state *spnego_state = gensec_security->private_data;
 142         if (spnego_state->state_position != SPNEGO_DONE
 143             && spnego_state->state_position != SPNEGO_FALLBACK) {
 144                 return NT_STATUS_INVALID_PARAMETER;
 145         }
 146
 147         return gensec_session_key(spnego_state->sub_sec_security,
 148                                   session_key);
 149 }
 150
 151 /** Fallback to another GENSEC mechanism, based on magic strings
 152  *
 153  * This is the 'fallback' case, where we don't get SPENGO, and have to
 154  * try all the other options (and hope they all have a magic string
 155  * they check)
 156 */
 157
 158 static NTSTATUS gensec_spengo_server_try_fallback(struct gensec_security *gensec_security,
 159                                                   struct spnego_state *spnego_state,
 160                                                   TALLOC_CTX *out_mem_ctx,
 161                                                   const DATA_BLOB in, DATA_BLOB *out)
 162 {
 163         int i;
 164         int num_ops;
 165         const struct gensec_security_ops **all_ops = gensec_security_all(&num_ops);
 166         for (i=0; i < num_ops; i++) {
 167                 NTSTATUS nt_status;
 168                 if (!all_ops[i]->oid) {
 169                         continue;
 170                 }
 171                 nt_status = gensec_subcontext_start(gensec_security,
 172                                                     &spnego_state->sub_sec_security);
 173                 if (!NT_STATUS_IS_OK(nt_status)) {
 174                         return nt_status;
 175                 }
 176                 /* select the sub context */
 177                 nt_status = gensec_start_mech_by_oid(spnego_state->sub_sec_security,
 178                                                      all_ops[i]->oid);
 179                 if (!NT_STATUS_IS_OK(nt_status)) {
 180                         gensec_end(&spnego_state->sub_sec_security);
 181                                         continue;
 182                 }
 183                 nt_status = gensec_update(spnego_state->sub_sec_security,
 184                                                           out_mem_ctx, in, out);
 185                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 186                         spnego_state->state_position = SPNEGO_FALLBACK;
 187                         return nt_status;
 188                 }
 189                 gensec_end(&spnego_state->sub_sec_security);
 190         }
 191         DEBUG(1, ("Failed to parse SPENGO request\n"));
 192         return NT_STATUS_INVALID_PARAMETER;
 193
 194 }
 195
 196 static NTSTATUS gensec_spnego_update(struct gensec_security *gensec_security, TALLOC_CTX *out_mem_ctx,
 197                                const DATA_BLOB in, DATA_BLOB *out)
 198 {
 199         struct spnego_state *spnego_state = gensec_security->private_data;
 200         DATA_BLOB null_data_blob = data_blob(NULL, 0);
 201         DATA_BLOB unwrapped_out;
 202         struct spnego_data spnego_out;
 203         struct spnego_data spnego;
 204
 205         ssize_t len;
 206
 207         if (!out_mem_ctx) {
 208                 out_mem_ctx = spnego_state->mem_ctx;
 209         }
 210
 211         /* and switch into the state machine */
 212
 213         switch (spnego_state->state_position) {
 214         case SPNEGO_FALLBACK:
 215                 return gensec_update(spnego_state->sub_sec_security,
 216                                      out_mem_ctx, in, out);
 217         case SPNEGO_SERVER_START:
 218         {
 219                 if (in.length) {
 220                         len = spnego_read_data(in, &spnego);
 221                         if (len == -1) {
 222                                 return gensec_spengo_server_try_fallback(gensec_security, spnego_state, out_mem_ctx, in, out);
 223                         } else {
 224                                 /* client sent NegTargetInit */
 225                         }
 226                 } else {
 227                         /* server needs to send NegTargetInit */
 228                 }
 229         }
 230
 231         case SPNEGO_CLIENT_START:
 232         {
 233                 /* The server offers a list of mechanisms */
 234
 235                 char **mechType;
 236                 char *my_mechs[] = {NULL, NULL};
 237                 int i;
 238                 NTSTATUS nt_status;
 239
 240                 if (!in.length) {
 241                         /* client to produce negTokenInit */
 242                         return NT_STATUS_INVALID_PARAMETER;
 243                 }
 244
 245                 len = spnego_read_data(in, &spnego);
 246
 247                 if (len == -1) {
 248                         return NT_STATUS_INVALID_PARAMETER;
 249                 }
 250
 251                 /* OK, so it's real SPNEGO, check the packet's the one we expect */
 252                 if (spnego.type != spnego_state->expected_packet) {
 253                         spnego_free_data(&spnego);
 254                         DEBUG(1, ("Invalid SPENGO request: %d, expected %d\n", spnego.type,
 255                                   spnego_state->expected_packet));
 256                         return NT_STATUS_INVALID_PARAMETER;
 257                 }
 258
 259                 mechType = spnego.negTokenInit.mechTypes;
 260                 for (i=0; mechType && mechType[i]; i++) {
 261                         nt_status = gensec_client_start(&spnego_state->sub_sec_security);
 262                         if (!NT_STATUS_IS_OK(nt_status)) {
 263                                 break;
 264                         }
 265                         /* select the sub context */
 266                         nt_status = gensec_start_mech_by_oid(spnego_state->sub_sec_security,
 267                                                              mechType[i]);
 268                         if (!NT_STATUS_IS_OK(nt_status)) {
 269                                 gensec_end(&spnego_state->sub_sec_security);
 270                                 continue;
 271                         }
 272
 273                         if (i == 0) {
 274                                 nt_status = gensec_update(spnego_state->sub_sec_security,
 275                                                           out_mem_ctx,
 276                                                           spnego.negTokenInit.mechToken,
 277                                                           &unwrapped_out);
 278                         } else {
 279                                 /* only get the helping start blob for the first OID */
 280                                 nt_status = gensec_update(spnego_state->sub_sec_security,
 281                                                           out_mem_ctx,
 282                                                           null_data_blob,
 283                                                           &unwrapped_out);
 284                         }
 285                         if (!NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 286                                 DEBUG(1, ("SPENGO(%s) NEG_TOKEN_INIT failed: %s\n",
 287                                           spnego_state->sub_sec_security->ops->name, nt_errstr(nt_status)));
 288                                 gensec_end(&spnego_state->sub_sec_security);
 289                         } else {
 290                                 break;
 291                         }
 292                 }
 293                 if (!mechType || !mechType[i]) {
 294                         DEBUG(1, ("SPENGO: Could not find a suitable mechtype in NEG_TOKEN_INIT\n"));
 295                 }
 296
 297                 spnego_free_data(&spnego);
 298                 if (!NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 299                         return nt_status;
 300                 }
 301
 302                 /* compose reply */
 303                 my_mechs[0] = spnego_state->sub_sec_security->ops->oid;
 304
 305                 spnego_out.type = SPNEGO_NEG_TOKEN_INIT;
 306                 spnego_out.negTokenInit.mechTypes = my_mechs;
 307                 spnego_out.negTokenInit.reqFlags = 0;
 308                 spnego_out.negTokenInit.mechListMIC = null_data_blob;
 309                 spnego_out.negTokenInit.mechToken = unwrapped_out;
 310
 311                 if (spnego_write_data(out_mem_ctx, out, &spnego_out) == -1) {
 312                         DEBUG(1, ("Failed to write SPENGO reply to NEG_TOKEN_INIT\n"));
 313                                 return NT_STATUS_INVALID_PARAMETER;
 314                 }
 315
 316                 /* set next state */
 317                 spnego_state->expected_packet = SPNEGO_NEG_TOKEN_TARG;
 318                 spnego_state->state_position = SPNEGO_TARG;
 319
 320                 return nt_status;
 321         }
 322         case SPNEGO_TARG:
 323         {
 324                 NTSTATUS nt_status;
 325                 if (!in.length) {
 326                         return NT_STATUS_INVALID_PARAMETER;
 327                 }
 328
 329                 len = spnego_read_data(in, &spnego);
 330
 331                 if (len == -1) {
 332                         return NT_STATUS_INVALID_PARAMETER;
 333                 }
 334
 335                 /* OK, so it's real SPNEGO, check the packet's the one we expect */
 336                 if (spnego.type != spnego_state->expected_packet) {
 337                         spnego_free_data(&spnego);
 338                         DEBUG(1, ("Invalid SPENGO request: %d, expected %d\n", spnego.type,
 339                                   spnego_state->expected_packet));
 340                         return NT_STATUS_INVALID_PARAMETER;
 341                 }
 342
 343                 if (spnego.negTokenTarg.negResult == SPNEGO_REJECT) {
 344                         return NT_STATUS_ACCESS_DENIED;
 345                 }
 346
 347                 if (spnego.negTokenTarg.responseToken.length) {
 348                         nt_status = gensec_update(spnego_state->sub_sec_security,
 349                                                   out_mem_ctx,
 350                                                   spnego.negTokenTarg.responseToken,
 351                                                   &unwrapped_out);
 352                 } else {
 353                         unwrapped_out = data_blob(NULL, 0);
 354                         nt_status = NT_STATUS_OK;
 355                 }
 356
 357                 if (NT_STATUS_IS_OK(nt_status)
 358                     && (spnego.negTokenTarg.negResult != SPNEGO_ACCEPT_COMPLETED)) {
 359                         nt_status = NT_STATUS_INVALID_PARAMETER;
 360                 }
 361
 362                 spnego_state->result = spnego.negTokenTarg.negResult;
 363                 spnego_free_data(&spnego);
 364
 365                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 366                         /* compose reply */
 367                         spnego_out.type = SPNEGO_NEG_TOKEN_TARG;
 368                         spnego_out.negTokenTarg.negResult = SPNEGO_ACCEPT_INCOMPLETE;
 369                         spnego_out.negTokenTarg.supportedMech
 370                                 = spnego_state->sub_sec_security->ops->oid;
 371                         spnego_out.negTokenTarg.responseToken = unwrapped_out;
 372                         spnego_out.negTokenTarg.mechListMIC = null_data_blob;
 373
 374                         if (spnego_write_data(out_mem_ctx, out, &spnego_out) == -1) {
 375                                 DEBUG(1, ("Failed to write SPENGO reply to NEG_TOKEN_TARG\n"));
 376                                 return NT_STATUS_INVALID_PARAMETER;
 377                         }
 378                         spnego_state->state_position = SPNEGO_TARG;
 379                 } else if (NT_STATUS_IS_OK(nt_status)) {
 380                         spnego_state->state_position = SPNEGO_DONE;
 381                 } else {
 382                         DEBUG(1, ("SPENGO(%s) login failed: %s\n",
 383                                   spnego_state->sub_sec_security->ops->name,
 384                                   nt_errstr(nt_status)));
 385                         return nt_status;
 386                 }
 387
 388                 return nt_status;
 389         }
 390         default:
 391                 spnego_free_data(&spnego);
 392                 DEBUG(1, ("Invalid SPENGO request: %d\n", spnego.type));
 393                 return NT_STATUS_INVALID_PARAMETER;
 394         }
 395 }
 396
 397 static void gensec_spnego_end(struct gensec_security *gensec_security)
 398 {
 399         struct spnego_state *spnego_state = gensec_security->private_data;
 400
 401         if (spnego_state->sub_sec_security) {
 402                 gensec_end(&spnego_state->sub_sec_security);
 403         }
 404
 405         talloc_destroy(spnego_state->mem_ctx);
 406
 407         gensec_security->private_data = NULL;
 408 }
 409
 410 static const struct gensec_security_ops gensec_spnego_security_ops = {
 411         .name           = "spnego",
 412         .sasl_name      = "GSS-SPNEGO",
 413         .auth_type      = DCERPC_AUTH_TYPE_SPNEGO,
 414         .oid            = OID_SPNEGO,
 415         .client_start   = gensec_spnego_client_start,
 416         .update         = gensec_spnego_update,
 417         .seal_packet    = gensec_spnego_seal_packet,
 418         .sign_packet    = gensec_spnego_sign_packet,
 419         .check_packet   = gensec_spnego_check_packet,
 420         .unseal_packet  = gensec_spnego_unseal_packet,
 421         .session_key    = gensec_spnego_session_key,
 422         .end            = gensec_spnego_end
 423 };
 424
 425 NTSTATUS gensec_spengo_init(void)
 426 {
 427         NTSTATUS ret;
 428         ret = register_backend("gensec", &gensec_spnego_security_ops);
 429         if (!NT_STATUS_IS_OK(ret)) {
 430                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 431                         gensec_spnego_security_ops.name));
 432                 return ret;
 433         }
 434
 435         return ret;
 436 }