source4/auth/gensec/gensec_gssapi.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Kerberos backend for GENSEC
   5
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004
   7    Copyright (C) Stefan Metzmacher <metze@samba.org> 2005
   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 #include "system/kerberos.h"
  27 #include "system/network.h"
  28 #include "auth/kerberos/kerberos.h"
  29 #include "librpc/gen_ndr/ndr_krb5pac.h"
  30 #include "auth/auth.h"
  31
  32 #undef DBGC_CLASS
  33 #define DBGC_CLASS DBGC_AUTH
  34
  35 struct gensec_gssapi_state {
  36         gss_ctx_id_t gssapi_context;
  37         struct gss_channel_bindings_struct *input_chan_bindings;
  38         gss_name_t server_name;
  39         gss_name_t client_name;
  40         OM_uint32 want_flags, got_flags;
  41         const gss_OID_desc *gss_oid;
  42
  43         DATA_BLOB session_key;
  44         DATA_BLOB pac;
  45
  46         struct smb_krb5_context *smb_krb5_context;
  47         krb5_ccache ccache;
  48         const char *ccache_name;
  49         krb5_keytab keytab;
  50
  51         gss_cred_id_t cred;
  52 };
  53
  54 static char *gssapi_error_string(TALLOC_CTX *mem_ctx,
  55                                  OM_uint32 maj_stat, OM_uint32 min_stat)
  56 {
  57         OM_uint32 disp_min_stat, disp_maj_stat;
  58         gss_buffer_desc maj_error_message;
  59         gss_buffer_desc min_error_message;
  60         OM_uint32 msg_ctx = 0;
  61
  62         char *ret;
  63
  64         maj_error_message.value = NULL;
  65         min_error_message.value = NULL;
  66
  67         disp_maj_stat = gss_display_status(&disp_min_stat, maj_stat, GSS_C_GSS_CODE,
  68                            GSS_C_NULL_OID, &msg_ctx, &maj_error_message);
  69         disp_maj_stat = gss_display_status(&disp_min_stat, min_stat, GSS_C_MECH_CODE,
  70                            GSS_C_NULL_OID, &msg_ctx, &min_error_message);
  71         ret = talloc_asprintf(mem_ctx, "%s: %s", (char *)maj_error_message.value, (char *)min_error_message.value);
  72
  73         gss_release_buffer(&disp_min_stat, &maj_error_message);
  74         gss_release_buffer(&disp_min_stat, &min_error_message);
  75
  76         return ret;
  77 }
  78
  79
  80 static int gensec_gssapi_destory(void *ptr)
  81 {
  82         struct gensec_gssapi_state *gensec_gssapi_state = ptr;
  83         OM_uint32 maj_stat, min_stat;
  84
  85         if (gensec_gssapi_state->cred != GSS_C_NO_CREDENTIAL) {
  86                 maj_stat = gss_release_cred(&min_stat,
  87                                             &gensec_gssapi_state->cred);
  88         }
  89
  90         if (gensec_gssapi_state->gssapi_context != GSS_C_NO_CONTEXT) {
  91                 maj_stat = gss_delete_sec_context (&min_stat,
  92                                                    &gensec_gssapi_state->gssapi_context,
  93                                                    GSS_C_NO_BUFFER);
  94         }
  95
  96         if (gensec_gssapi_state->server_name != GSS_C_NO_NAME) {
  97                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->server_name);
  98         }
  99         if (gensec_gssapi_state->client_name != GSS_C_NO_NAME) {
 100                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->client_name);
 101         }
 102         return 0;
 103 }
 104
 105 static NTSTATUS gensec_gssapi_start(struct gensec_security *gensec_security)
 106 {
 107         struct gensec_gssapi_state *gensec_gssapi_state;
 108         krb5_error_code ret;
 109
 110         gensec_gssapi_state = talloc(gensec_security, struct gensec_gssapi_state);
 111         if (!gensec_gssapi_state) {
 112                 return NT_STATUS_NO_MEMORY;
 113         }
 114
 115         gensec_security->private_data = gensec_gssapi_state;
 116
 117         gensec_gssapi_state->gssapi_context = GSS_C_NO_CONTEXT;
 118         gensec_gssapi_state->server_name = GSS_C_NO_NAME;
 119         gensec_gssapi_state->client_name = GSS_C_NO_NAME;
 120
 121         /* TODO: Fill in channel bindings */
 122         gensec_gssapi_state->input_chan_bindings = GSS_C_NO_CHANNEL_BINDINGS;
 123
 124         gensec_gssapi_state->want_flags = 0;
 125         gensec_gssapi_state->got_flags = 0;
 126
 127         gensec_gssapi_state->session_key = data_blob(NULL, 0);
 128         gensec_gssapi_state->pac = data_blob(NULL, 0);
 129
 130         gensec_gssapi_state->cred = GSS_C_NO_CREDENTIAL;
 131
 132         talloc_set_destructor(gensec_gssapi_state, gensec_gssapi_destory);
 133
 134         if (gensec_security->want_features & GENSEC_FEATURE_SESSION_KEY) {
 135 #ifndef HAVE_GSSKRB5_GET_INITIATOR_SUBKEY
 136                 /* GSSAPI won't give us the session keys, without the
 137                  * right hooks.  This is critical when requested, so
 138                  * fail outright. */
 139                 return NT_STATUS_INVALID_PARAMETER;
 140 #endif
 141         }
 142         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 143                 gensec_gssapi_state->want_flags |= GSS_C_INTEG_FLAG;
 144         }
 145         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 146                 gensec_gssapi_state->want_flags |= GSS_C_CONF_FLAG;
 147         }
 148         if (gensec_security->want_features & GENSEC_FEATURE_DCE_STYLE) {
 149 #ifndef GSS_C_DCE_STYLE
 150                 /* GSSAPI DCE_STYLE is critical when requested, so
 151                  * fail outright */
 152                 return NT_STATUS_INVALID_PARAMETER;
 153 #else
 154                 gensec_gssapi_state->want_flags |= GSS_C_DCE_STYLE;
 155 #endif
 156         }
 157
 158         gensec_gssapi_state->gss_oid = gss_mech_krb5;
 159
 160         ret = smb_krb5_init_context(gensec_gssapi_state,
 161                                     &gensec_gssapi_state->smb_krb5_context);
 162         if (ret) {
 163                 DEBUG(1,("gensec_krb5_start: krb5_init_context failed (%s)\n",
 164                          error_message(ret)));
 165                 return NT_STATUS_INTERNAL_ERROR;
 166         }
 167         return NT_STATUS_OK;
 168 }
 169
 170 static NTSTATUS gensec_gssapi_server_start(struct gensec_security *gensec_security)
 171 {
 172         NTSTATUS nt_status;
 173         OM_uint32 maj_stat, min_stat;
 174         struct gensec_gssapi_state *gensec_gssapi_state;
 175         struct cli_credentials *machine_account;
 176
 177         nt_status = gensec_gssapi_start(gensec_security);
 178         if (!NT_STATUS_IS_OK(nt_status)) {
 179                 return nt_status;
 180         }
 181
 182         gensec_gssapi_state = gensec_security->private_data;
 183
 184         machine_account = cli_credentials_init(gensec_gssapi_state);
 185         cli_credentials_set_conf(machine_account);
 186         nt_status = cli_credentials_set_machine_account(machine_account);
 187
 188         if (!NT_STATUS_IS_OK(nt_status)) {
 189                 DEBUG(3, ("Could not obtain machine account credentials from the local database\n"));
 190                 talloc_free(machine_account);
 191                 return nt_status;
 192         } else {
 193                 nt_status = create_memory_keytab(gensec_gssapi_state,
 194                                                  machine_account,
 195                                                  gensec_gssapi_state->smb_krb5_context,
 196                                                  &gensec_gssapi_state->keytab);
 197                 talloc_free(machine_account);
 198                 if (!NT_STATUS_IS_OK(nt_status)) {
 199                         DEBUG(3, ("Could not create memory keytab!\n"));
 200                         talloc_free(machine_account);
 201                         return nt_status;
 202                 }
 203         }
 204
 205         maj_stat = gsskrb5_acquire_cred(&min_stat,
 206                                         gensec_gssapi_state->keytab, NULL,
 207                                         NULL,
 208                                         GSS_C_INDEFINITE,
 209                                         GSS_C_NULL_OID_SET,
 210                                         GSS_C_ACCEPT,
 211                                         &gensec_gssapi_state->cred,
 212                                         NULL,
 213                                         NULL);
 214         if (maj_stat) {
 215                 DEBUG(1, ("Aquiring acceptor credentails failed: %s\n",
 216                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 217                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 218         }
 219
 220         return NT_STATUS_OK;
 221
 222 }
 223
 224 static NTSTATUS gensec_gssapi_client_start(struct gensec_security *gensec_security)
 225 {
 226         struct gensec_gssapi_state *gensec_gssapi_state;
 227         NTSTATUS nt_status;
 228         gss_buffer_desc name_token;
 229         OM_uint32 maj_stat, min_stat;
 230
 231         nt_status = gensec_gssapi_start(gensec_security);
 232         if (!NT_STATUS_IS_OK(nt_status)) {
 233                 return nt_status;
 234         }
 235
 236         gensec_gssapi_state = gensec_security->private_data;
 237
 238         name_token.value = talloc_asprintf(gensec_gssapi_state, "%s@%s",
 239                                            gensec_get_target_service(gensec_security),
 240                                            gensec_get_target_hostname(gensec_security));
 241         name_token.length = strlen(name_token.value);
 242
 243         maj_stat = gss_import_name (&min_stat,
 244                                     &name_token,
 245                                     GSS_C_NT_HOSTBASED_SERVICE,
 246                                     &gensec_gssapi_state->server_name);
 247         if (maj_stat) {
 248                 DEBUG(1, ("GSS Import name of %s failed: %s\n",
 249                           (char *)name_token.value,
 250                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 251                 return NT_STATUS_UNSUCCESSFUL;
 252         }
 253
 254         name_token.value = cli_credentials_get_principal(gensec_get_credentials(gensec_security),
 255                                                          gensec_gssapi_state),
 256         name_token.length = strlen(name_token.value);
 257
 258         maj_stat = gss_import_name (&min_stat,
 259                                     &name_token,
 260                                     GSS_C_NT_USER_NAME,
 261                                     &gensec_gssapi_state->client_name);
 262         if (maj_stat) {
 263                 DEBUG(1, ("GSS Import name of %s failed: %s\n",
 264                           (char *)name_token.value,
 265                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 266                 return NT_STATUS_UNSUCCESSFUL;
 267         }
 268
 269         nt_status = kinit_to_ccache(gensec_gssapi_state,
 270                                     gensec_get_credentials(gensec_security),
 271                                     gensec_gssapi_state->smb_krb5_context,
 272                                     &gensec_gssapi_state->ccache, &gensec_gssapi_state->ccache_name);
 273         if (!NT_STATUS_IS_OK(nt_status)) {
 274                 return nt_status;
 275         }
 276
 277         maj_stat = gsskrb5_acquire_cred(&min_stat,
 278                                         NULL, gensec_gssapi_state->ccache,
 279                                         gensec_gssapi_state->client_name,
 280                                         GSS_C_INDEFINITE,
 281                                         GSS_C_NULL_OID_SET,
 282                                         GSS_C_INITIATE,
 283                                         &gensec_gssapi_state->cred,
 284                                         NULL,
 285                                         NULL);
 286         if (maj_stat) {
 287                 DEBUG(1, ("Aquiring initiator credentails failed: %s\n",
 288                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 289                 return NT_STATUS_UNSUCCESSFUL;
 290         }
 291
 292         return NT_STATUS_OK;
 293 }
 294
 295
 296 /**
 297  * Check if the packet is one for this mechansim
 298  *
 299  * @param gensec_security GENSEC state
 300  * @param in The request, as a DATA_BLOB
 301  * @return Error, INVALID_PARAMETER if it's not a packet for us
 302  *                or NT_STATUS_OK if the packet is ok.
 303  */
 304
 305 static NTSTATUS gensec_gssapi_magic(struct gensec_security *gensec_security,
 306                                     const DATA_BLOB *in)
 307 {
 308         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 309                 return NT_STATUS_OK;
 310         } else {
 311                 return NT_STATUS_INVALID_PARAMETER;
 312         }
 313 }
 314
 315
 316 /**
 317  * Next state function for the GSSAPI GENSEC mechanism
 318  *
 319  * @param gensec_gssapi_state GSSAPI State
 320  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 321  * @param in The request, as a DATA_BLOB
 322  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 323  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 324  *                or NT_STATUS_OK if the user is authenticated.
 325  */
 326
 327 static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 328                                    TALLOC_CTX *out_mem_ctx,
 329                                    const DATA_BLOB in, DATA_BLOB *out)
 330 {
 331         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 332         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 333         OM_uint32 maj_stat, min_stat;
 334         OM_uint32 min_stat2;
 335         gss_buffer_desc input_token, output_token;
 336         gss_OID gss_oid_p;
 337         input_token.length = in.length;
 338         input_token.value = in.data;
 339
 340         switch (gensec_security->gensec_role) {
 341         case GENSEC_CLIENT:
 342         {
 343                 maj_stat = gss_init_sec_context(&min_stat,
 344                                                 gensec_gssapi_state->cred,
 345                                                 &gensec_gssapi_state->gssapi_context,
 346                                                 gensec_gssapi_state->server_name,
 347                                                 discard_const_p(gss_OID_desc, gensec_gssapi_state->gss_oid),
 348                                                 gensec_gssapi_state->want_flags,
 349                                                 0,
 350                                                 gensec_gssapi_state->input_chan_bindings,
 351                                                 &input_token,
 352                                                 NULL,
 353                                                 &output_token,
 354                                                 &gensec_gssapi_state->got_flags, /* ret flags */
 355                                                 NULL);
 356                 break;
 357         }
 358         case GENSEC_SERVER:
 359         {
 360                 maj_stat = gss_accept_sec_context(&min_stat,
 361                                                   &gensec_gssapi_state->gssapi_context,
 362                                                   gensec_gssapi_state->cred,
 363                                                   &input_token,
 364                                                   gensec_gssapi_state->input_chan_bindings,
 365                                                   &gensec_gssapi_state->client_name,
 366                                                   &gss_oid_p,
 367                                                   &output_token,
 368                                                   &gensec_gssapi_state->got_flags,
 369                                                   NULL,
 370                                                   NULL);
 371                 gensec_gssapi_state->gss_oid = gss_oid_p;
 372                 break;
 373         }
 374         default:
 375                 return NT_STATUS_INVALID_PARAMETER;
 376
 377         }
 378
 379         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 380         gss_release_buffer(&min_stat2, &output_token);
 381
 382         if (maj_stat == GSS_S_COMPLETE) {
 383                 return NT_STATUS_OK;
 384         } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 385                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 386         } else {
 387                 if (maj_stat == GSS_S_FAILURE
 388                     && (min_stat == KRB5KRB_AP_ERR_BADVERSION || min_stat == KRB5KRB_AP_ERR_MSG_TYPE)) {
 389                         /* garbage input, possibly from the auto-mech detection */
 390                         return NT_STATUS_INVALID_PARAMETER;
 391                 }
 392                 DEBUG(1, ("GSS Update failed: %s\n",
 393                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 394                 return nt_status;
 395         }
 396 }
 397
 398 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 399                                    TALLOC_CTX *mem_ctx,
 400                                    const DATA_BLOB *in,
 401                                    DATA_BLOB *out)
 402 {
 403         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 404         OM_uint32 maj_stat, min_stat;
 405         gss_buffer_desc input_token, output_token;
 406         int conf_state;
 407         input_token.length = in->length;
 408         input_token.value = in->data;
 409
 410         maj_stat = gss_wrap(&min_stat,
 411                             gensec_gssapi_state->gssapi_context,
 412                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 413                             GSS_C_QOP_DEFAULT,
 414                             &input_token,
 415                             &conf_state,
 416                             &output_token);
 417         if (GSS_ERROR(maj_stat)) {
 418                 DEBUG(1, ("GSS Wrap failed: %s\n",
 419                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 420                 return NT_STATUS_ACCESS_DENIED;
 421         }
 422         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 423
 424         gss_release_buffer(&min_stat, &output_token);
 425
 426         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 427             && !conf_state) {
 428                 return NT_STATUS_ACCESS_DENIED;
 429         }
 430         return NT_STATUS_OK;
 431 }
 432
 433 static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 434                                      TALLOC_CTX *mem_ctx,
 435                                      const DATA_BLOB *in,
 436                                      DATA_BLOB *out)
 437 {
 438         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 439         OM_uint32 maj_stat, min_stat;
 440         gss_buffer_desc input_token, output_token;
 441         int conf_state;
 442         gss_qop_t qop_state;
 443         input_token.length = in->length;
 444         input_token.value = in->data;
 445
 446         maj_stat = gss_unwrap(&min_stat,
 447                               gensec_gssapi_state->gssapi_context,
 448                               &input_token,
 449                               &output_token,
 450                               &conf_state,
 451                               &qop_state);
 452         if (GSS_ERROR(maj_stat)) {
 453                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 454                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 455                 return NT_STATUS_ACCESS_DENIED;
 456         }
 457         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 458
 459         gss_release_buffer(&min_stat, &output_token);
 460
 461         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 462             && !conf_state) {
 463                 return NT_STATUS_ACCESS_DENIED;
 464         }
 465         return NT_STATUS_OK;
 466 }
 467
 468 static size_t gensec_gssapi_sig_size(struct gensec_security *gensec_security)
 469 {
 470         /* not const but work for DCERPC packets and arcfour */
 471         return 45;
 472 }
 473
 474 static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_security,
 475                                           TALLOC_CTX *mem_ctx,
 476                                           uint8_t *data, size_t length,
 477                                           const uint8_t *whole_pdu, size_t pdu_length,
 478                                           DATA_BLOB *sig)
 479 {
 480         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 481         OM_uint32 maj_stat, min_stat;
 482         gss_buffer_desc input_token, output_token;
 483         int conf_state;
 484         ssize_t sig_length = 0;
 485
 486         input_token.length = length;
 487         input_token.value = data;
 488
 489         maj_stat = gss_wrap(&min_stat,
 490                             gensec_gssapi_state->gssapi_context,
 491                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 492                             GSS_C_QOP_DEFAULT,
 493                             &input_token,
 494                             &conf_state,
 495                             &output_token);
 496         if (GSS_ERROR(maj_stat)) {
 497                 DEBUG(1, ("GSS Wrap failed: %s\n",
 498                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 499                 return NT_STATUS_ACCESS_DENIED;
 500         }
 501
 502         if (output_token.length < length) {
 503                 return NT_STATUS_INTERNAL_ERROR;
 504         }
 505
 506         sig_length = 45;
 507
 508         memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);
 509         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 510
 511         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 512         dump_data_pw("gensec_gssapi_seal_packet: clear\n", data, length);
 513         dump_data_pw("gensec_gssapi_seal_packet: sealed\n", ((uint8_t *)output_token.value) + sig_length, output_token.length - sig_length);
 514
 515         gss_release_buffer(&min_stat, &output_token);
 516
 517         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 518             && !conf_state) {
 519                 return NT_STATUS_ACCESS_DENIED;
 520         }
 521         return NT_STATUS_OK;
 522 }
 523
 524 static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_security,
 525                                             TALLOC_CTX *mem_ctx,
 526                                             uint8_t *data, size_t length,
 527                                             const uint8_t *whole_pdu, size_t pdu_length,
 528                                             const DATA_BLOB *sig)
 529 {
 530         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 531         OM_uint32 maj_stat, min_stat;
 532         gss_buffer_desc input_token, output_token;
 533         int conf_state;
 534         gss_qop_t qop_state;
 535         DATA_BLOB in;
 536
 537         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 538
 539         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 540
 541         memcpy(in.data, sig->data, sig->length);
 542         memcpy(in.data + sig->length, data, length);
 543
 544         input_token.length = in.length;
 545         input_token.value = in.data;
 546
 547         maj_stat = gss_unwrap(&min_stat,
 548                               gensec_gssapi_state->gssapi_context,
 549                               &input_token,
 550                               &output_token,
 551                               &conf_state,
 552                               &qop_state);
 553         if (GSS_ERROR(maj_stat)) {
 554                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 555                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 556                 return NT_STATUS_ACCESS_DENIED;
 557         }
 558
 559         if (output_token.length != length) {
 560                 return NT_STATUS_INTERNAL_ERROR;
 561         }
 562
 563         memcpy(data, output_token.value, length);
 564
 565         gss_release_buffer(&min_stat, &output_token);
 566
 567         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 568             && !conf_state) {
 569                 return NT_STATUS_ACCESS_DENIED;
 570         }
 571         return NT_STATUS_OK;
 572 }
 573
 574 static NTSTATUS gensec_gssapi_sign_packet(struct gensec_security *gensec_security,
 575                                           TALLOC_CTX *mem_ctx,
 576                                           const uint8_t *data, size_t length,
 577                                           const uint8_t *whole_pdu, size_t pdu_length,
 578                                           DATA_BLOB *sig)
 579 {
 580         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 581         OM_uint32 maj_stat, min_stat;
 582         gss_buffer_desc input_token, output_token;
 583         int conf_state;
 584         ssize_t sig_length = 0;
 585
 586         input_token.length = length;
 587         input_token.value = discard_const_p(uint8_t *, data);
 588
 589         maj_stat = gss_wrap(&min_stat,
 590                             gensec_gssapi_state->gssapi_context,
 591                             0,
 592                             GSS_C_QOP_DEFAULT,
 593                             &input_token,
 594                             &conf_state,
 595                             &output_token);
 596         if (GSS_ERROR(maj_stat)) {
 597                 DEBUG(1, ("GSS Wrap failed: %s\n",
 598                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 599                 return NT_STATUS_ACCESS_DENIED;
 600         }
 601
 602         if (output_token.length < length) {
 603                 return NT_STATUS_INTERNAL_ERROR;
 604         }
 605
 606         sig_length = 45;
 607
 608         /*memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);*/
 609         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 610
 611         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 612
 613         gss_release_buffer(&min_stat, &output_token);
 614
 615         return NT_STATUS_OK;
 616 }
 617
 618 static NTSTATUS gensec_gssapi_check_packet(struct gensec_security *gensec_security,
 619                                            TALLOC_CTX *mem_ctx,
 620                                            const uint8_t *data, size_t length,
 621                                            const uint8_t *whole_pdu, size_t pdu_length,
 622                                            const DATA_BLOB *sig)
 623 {
 624         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 625         OM_uint32 maj_stat, min_stat;
 626         gss_buffer_desc input_token, output_token;
 627         int conf_state;
 628         gss_qop_t qop_state;
 629         DATA_BLOB in;
 630
 631         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 632
 633         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 634
 635         memcpy(in.data, sig->data, sig->length);
 636         memcpy(in.data + sig->length, data, length);
 637
 638         input_token.length = in.length;
 639         input_token.value = in.data;
 640
 641         maj_stat = gss_unwrap(&min_stat,
 642                               gensec_gssapi_state->gssapi_context,
 643                               &input_token,
 644                               &output_token,
 645                               &conf_state,
 646                               &qop_state);
 647         if (GSS_ERROR(maj_stat)) {
 648                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 649                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 650                 return NT_STATUS_ACCESS_DENIED;
 651         }
 652
 653         if (output_token.length != length) {
 654                 return NT_STATUS_INTERNAL_ERROR;
 655         }
 656
 657         gss_release_buffer(&min_stat, &output_token);
 658
 659         return NT_STATUS_OK;
 660 }
 661
 662 static BOOL gensec_gssapi_have_feature(struct gensec_security *gensec_security,
 663                                        uint32_t feature)
 664 {
 665         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 666         if (feature & GENSEC_FEATURE_SIGN) {
 667                 return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
 668         }
 669         if (feature & GENSEC_FEATURE_SEAL) {
 670                 return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
 671         }
 672         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 673 #ifdef HAVE_GSSKRB5_GET_INITIATOR_SUBKEY
 674                 if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 675                     && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements, gensec_gssapi_state->gss_oid->length) == 0)) {
 676                         return True;
 677                 }
 678 #endif
 679         }
 680         return False;
 681 }
 682
 683 static NTSTATUS gensec_gssapi_session_key(struct gensec_security *gensec_security,
 684                                           DATA_BLOB *session_key)
 685 {
 686         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 687
 688         if (gensec_gssapi_state->session_key.data) {
 689                 *session_key = gensec_gssapi_state->session_key;
 690                 return NT_STATUS_OK;
 691         }
 692
 693 #ifdef HAVE_GSSKRB5_GET_INITIATOR_SUBKEY
 694         /* Ensure we only call this for GSSAPI/krb5, otherwise things could get very ugly */
 695         if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 696             && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 697                        gensec_gssapi_state->gss_oid->length) == 0)) {
 698                 OM_uint32 maj_stat, min_stat;
 699                 gss_buffer_desc skey;
 700
 701                 maj_stat = gsskrb5_get_initiator_subkey(&min_stat,
 702                                                         gensec_gssapi_state->gssapi_context,
 703                                                         &skey);
 704
 705                 if (maj_stat == 0) {
 706                         DEBUG(10, ("Got KRB5 session key of length %d\n",  skey.length));
 707                         gensec_gssapi_state->session_key = data_blob_talloc(gensec_gssapi_state,
 708                                                                             skey.value, skey.length);
 709                         *session_key = gensec_gssapi_state->session_key;
 710                         dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 711
 712                         gss_release_buffer(&min_stat, &skey);
 713                         return NT_STATUS_OK;
 714                 }
 715                 return NT_STATUS_NO_USER_SESSION_KEY;
 716         }
 717 #endif
 718
 719         DEBUG(1, ("NO session key for this mech\n"));
 720         return NT_STATUS_NO_USER_SESSION_KEY;
 721 }
 722
 723 static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_security,
 724                                          struct auth_session_info **_session_info)
 725 {
 726         NTSTATUS nt_status;
 727         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 728         struct auth_serversupplied_info *server_info = NULL;
 729         struct auth_session_info *session_info = NULL;
 730         char *p;
 731         char *principal;
 732         const char *account_name;
 733         const char *realm;
 734         OM_uint32 maj_stat, min_stat;
 735         gss_buffer_desc name_token;
 736
 737         maj_stat = gss_display_name (&min_stat,
 738                                      gensec_gssapi_state->client_name,
 739                                      &name_token,
 740                                      NULL);
 741         if (maj_stat) {
 742                 return NT_STATUS_FOOBAR;
 743         }
 744
 745         principal = talloc_strndup(gensec_gssapi_state, name_token.value, name_token.length);
 746
 747         gss_release_buffer(&min_stat, &name_token);
 748
 749         NT_STATUS_HAVE_NO_MEMORY(principal);
 750
 751         p = strchr(principal, '@');
 752         if (p) {
 753                 *p = '\0';
 754                 p++;
 755                 realm = p;
 756         } else {
 757                 realm = lp_realm();
 758         }
 759         account_name = principal;
 760
 761         /* IF we have the PAC - otherwise we need to get this
 762          * data from elsewere - local ldb, or (TODO) lookup of some
 763          * kind...
 764          *
 765          * when heimdal can generate the PAC, we should fail if there's
 766          * no PAC present
 767          */
 768
 769         {
 770                 DATA_BLOB user_sess_key = data_blob(NULL, 0);
 771                 DATA_BLOB lm_sess_key = data_blob(NULL, 0);
 772                 /* TODO: should we pass the krb5 session key in here? */
 773                 nt_status = sam_get_server_info(gensec_gssapi_state, account_name, realm,
 774                                                 user_sess_key, lm_sess_key,
 775                                                 &server_info);
 776                 talloc_free(principal);
 777                 NT_STATUS_NOT_OK_RETURN(nt_status);
 778         }
 779
 780         /* references the server_info into the session_info */
 781         nt_status = auth_generate_session_info(gensec_gssapi_state, server_info, &session_info);
 782         talloc_free(server_info);
 783         NT_STATUS_NOT_OK_RETURN(nt_status);
 784
 785         nt_status = gensec_gssapi_session_key(gensec_security, &session_info->session_key);
 786         NT_STATUS_NOT_OK_RETURN(nt_status);
 787
 788         *_session_info = session_info;
 789
 790         return NT_STATUS_OK;
 791 }
 792
 793 static const char *gensec_krb5_oids[] = {
 794         GENSEC_OID_KERBEROS5,
 795         GENSEC_OID_KERBEROS5_OLD,
 796         NULL
 797 };
 798
 799 /* As a server, this could in theory accept any GSSAPI mech */
 800 static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
 801         .name           = "gssapi_krb5",
 802         .oid            = gensec_krb5_oids,
 803         .client_start   = gensec_gssapi_client_start,
 804         .server_start   = gensec_gssapi_server_start,
 805         .magic          = gensec_gssapi_magic,
 806         .update         = gensec_gssapi_update,
 807         .session_key    = gensec_gssapi_session_key,
 808         .session_info   = gensec_gssapi_session_info,
 809         .sig_size       = gensec_gssapi_sig_size,
 810         .sign_packet    = gensec_gssapi_sign_packet,
 811         .check_packet   = gensec_gssapi_check_packet,
 812         .seal_packet    = gensec_gssapi_seal_packet,
 813         .unseal_packet  = gensec_gssapi_unseal_packet,
 814         .wrap           = gensec_gssapi_wrap,
 815         .unwrap         = gensec_gssapi_unwrap,
 816         .have_feature   = gensec_gssapi_have_feature,
 817         .enabled        = False
 818 };
 819
 820 NTSTATUS gensec_gssapi_init(void)
 821 {
 822         NTSTATUS ret;
 823
 824         ret = gensec_register(&gensec_gssapi_krb5_security_ops);
 825         if (!NT_STATUS_IS_OK(ret)) {
 826                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 827                         gensec_gssapi_krb5_security_ops.name));
 828                 return ret;
 829         }
 830
 831         return ret;
 832 }