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> 2004-2005
   7    Copyright (C) Stefan Metzmacher <metze@samba.org> 2004-2005
   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         struct cli_credentials *creds = gensec_get_credentials(gensec_security);
 228         NTSTATUS nt_status;
 229         gss_buffer_desc name_token;
 230         OM_uint32 maj_stat, min_stat;
 231
 232         nt_status = gensec_gssapi_start(gensec_security);
 233         if (!NT_STATUS_IS_OK(nt_status)) {
 234                 return nt_status;
 235         }
 236
 237         gensec_gssapi_state = gensec_security->private_data;
 238
 239         name_token.value = talloc_asprintf(gensec_gssapi_state, "%s@%s",
 240                                            gensec_get_target_service(gensec_security),
 241                                            gensec_get_target_hostname(gensec_security));
 242         name_token.length = strlen(name_token.value);
 243
 244         maj_stat = gss_import_name (&min_stat,
 245                                     &name_token,
 246                                     GSS_C_NT_HOSTBASED_SERVICE,
 247                                     &gensec_gssapi_state->server_name);
 248         if (maj_stat) {
 249                 DEBUG(1, ("GSS Import name of %s failed: %s\n",
 250                           (char *)name_token.value,
 251                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 252                 return NT_STATUS_UNSUCCESSFUL;
 253         }
 254
 255         name_token.value = cli_credentials_get_principal(creds,
 256                                                          gensec_gssapi_state);
 257         name_token.length = strlen(name_token.value);
 258
 259         maj_stat = gss_import_name (&min_stat,
 260                                     &name_token,
 261                                     GSS_C_NT_USER_NAME,
 262                                     &gensec_gssapi_state->client_name);
 263         if (maj_stat) {
 264                 DEBUG(1, ("GSS Import name of %s failed: %s\n",
 265                           (char *)name_token.value,
 266                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 267                 return NT_STATUS_UNSUCCESSFUL;
 268         }
 269
 270         nt_status = kinit_to_ccache(gensec_gssapi_state,
 271                                     creds,
 272                                     gensec_gssapi_state->smb_krb5_context,
 273                                     &gensec_gssapi_state->ccache, &gensec_gssapi_state->ccache_name);
 274         if (!NT_STATUS_IS_OK(nt_status)) {
 275                 return nt_status;
 276         }
 277
 278         maj_stat = gsskrb5_acquire_cred(&min_stat,
 279                                         NULL, gensec_gssapi_state->ccache,
 280                                         gensec_gssapi_state->client_name,
 281                                         GSS_C_INDEFINITE,
 282                                         GSS_C_NULL_OID_SET,
 283                                         GSS_C_INITIATE,
 284                                         &gensec_gssapi_state->cred,
 285                                         NULL,
 286                                         NULL);
 287         if (maj_stat) {
 288                 DEBUG(1, ("Aquiring initiator credentails failed: %s\n",
 289                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 290                 return NT_STATUS_UNSUCCESSFUL;
 291         }
 292
 293         return NT_STATUS_OK;
 294 }
 295
 296
 297 /**
 298  * Check if the packet is one for this mechansim
 299  *
 300  * @param gensec_security GENSEC state
 301  * @param in The request, as a DATA_BLOB
 302  * @return Error, INVALID_PARAMETER if it's not a packet for us
 303  *                or NT_STATUS_OK if the packet is ok.
 304  */
 305
 306 static NTSTATUS gensec_gssapi_magic(struct gensec_security *gensec_security,
 307                                     const DATA_BLOB *in)
 308 {
 309         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 310                 return NT_STATUS_OK;
 311         } else {
 312                 return NT_STATUS_INVALID_PARAMETER;
 313         }
 314 }
 315
 316
 317 /**
 318  * Next state function for the GSSAPI GENSEC mechanism
 319  *
 320  * @param gensec_gssapi_state GSSAPI State
 321  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 322  * @param in The request, as a DATA_BLOB
 323  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 324  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 325  *                or NT_STATUS_OK if the user is authenticated.
 326  */
 327
 328 static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 329                                    TALLOC_CTX *out_mem_ctx,
 330                                    const DATA_BLOB in, DATA_BLOB *out)
 331 {
 332         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 333         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 334         OM_uint32 maj_stat, min_stat;
 335         OM_uint32 min_stat2;
 336         gss_buffer_desc input_token, output_token;
 337         gss_OID gss_oid_p;
 338         input_token.length = in.length;
 339         input_token.value = in.data;
 340
 341         switch (gensec_security->gensec_role) {
 342         case GENSEC_CLIENT:
 343         {
 344                 maj_stat = gss_init_sec_context(&min_stat,
 345                                                 gensec_gssapi_state->cred,
 346                                                 &gensec_gssapi_state->gssapi_context,
 347                                                 gensec_gssapi_state->server_name,
 348                                                 discard_const_p(gss_OID_desc, gensec_gssapi_state->gss_oid),
 349                                                 gensec_gssapi_state->want_flags,
 350                                                 0,
 351                                                 gensec_gssapi_state->input_chan_bindings,
 352                                                 &input_token,
 353                                                 NULL,
 354                                                 &output_token,
 355                                                 &gensec_gssapi_state->got_flags, /* ret flags */
 356                                                 NULL);
 357                 break;
 358         }
 359         case GENSEC_SERVER:
 360         {
 361                 maj_stat = gss_accept_sec_context(&min_stat,
 362                                                   &gensec_gssapi_state->gssapi_context,
 363                                                   gensec_gssapi_state->cred,
 364                                                   &input_token,
 365                                                   gensec_gssapi_state->input_chan_bindings,
 366                                                   &gensec_gssapi_state->client_name,
 367                                                   &gss_oid_p,
 368                                                   &output_token,
 369                                                   &gensec_gssapi_state->got_flags,
 370                                                   NULL,
 371                                                   NULL);
 372                 gensec_gssapi_state->gss_oid = gss_oid_p;
 373                 break;
 374         }
 375         default:
 376                 return NT_STATUS_INVALID_PARAMETER;
 377
 378         }
 379
 380         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 381         gss_release_buffer(&min_stat2, &output_token);
 382
 383         if (maj_stat == GSS_S_COMPLETE) {
 384                 return NT_STATUS_OK;
 385         } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 386                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 387         } else {
 388                 if (maj_stat == GSS_S_FAILURE
 389                     && (min_stat == KRB5KRB_AP_ERR_BADVERSION || min_stat == KRB5KRB_AP_ERR_MSG_TYPE)) {
 390                         /* garbage input, possibly from the auto-mech detection */
 391                         return NT_STATUS_INVALID_PARAMETER;
 392                 }
 393                 DEBUG(1, ("GSS Update failed: %s\n",
 394                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 395                 return nt_status;
 396         }
 397 }
 398
 399 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 400                                    TALLOC_CTX *mem_ctx,
 401                                    const DATA_BLOB *in,
 402                                    DATA_BLOB *out)
 403 {
 404         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 405         OM_uint32 maj_stat, min_stat;
 406         gss_buffer_desc input_token, output_token;
 407         int conf_state;
 408         input_token.length = in->length;
 409         input_token.value = in->data;
 410
 411         maj_stat = gss_wrap(&min_stat,
 412                             gensec_gssapi_state->gssapi_context,
 413                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 414                             GSS_C_QOP_DEFAULT,
 415                             &input_token,
 416                             &conf_state,
 417                             &output_token);
 418         if (GSS_ERROR(maj_stat)) {
 419                 DEBUG(1, ("GSS Wrap failed: %s\n",
 420                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 421                 return NT_STATUS_ACCESS_DENIED;
 422         }
 423         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 424
 425         gss_release_buffer(&min_stat, &output_token);
 426
 427         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 428             && !conf_state) {
 429                 return NT_STATUS_ACCESS_DENIED;
 430         }
 431         return NT_STATUS_OK;
 432 }
 433
 434 static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 435                                      TALLOC_CTX *mem_ctx,
 436                                      const DATA_BLOB *in,
 437                                      DATA_BLOB *out)
 438 {
 439         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 440         OM_uint32 maj_stat, min_stat;
 441         gss_buffer_desc input_token, output_token;
 442         int conf_state;
 443         gss_qop_t qop_state;
 444         input_token.length = in->length;
 445         input_token.value = in->data;
 446
 447         maj_stat = gss_unwrap(&min_stat,
 448                               gensec_gssapi_state->gssapi_context,
 449                               &input_token,
 450                               &output_token,
 451                               &conf_state,
 452                               &qop_state);
 453         if (GSS_ERROR(maj_stat)) {
 454                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 455                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 456                 return NT_STATUS_ACCESS_DENIED;
 457         }
 458         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 459
 460         gss_release_buffer(&min_stat, &output_token);
 461
 462         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 463             && !conf_state) {
 464                 return NT_STATUS_ACCESS_DENIED;
 465         }
 466         return NT_STATUS_OK;
 467 }
 468
 469 static size_t gensec_gssapi_sig_size(struct gensec_security *gensec_security)
 470 {
 471         /* not const but work for DCERPC packets and arcfour */
 472         return 45;
 473 }
 474
 475 static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_security,
 476                                           TALLOC_CTX *mem_ctx,
 477                                           uint8_t *data, size_t length,
 478                                           const uint8_t *whole_pdu, size_t pdu_length,
 479                                           DATA_BLOB *sig)
 480 {
 481         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 482         OM_uint32 maj_stat, min_stat;
 483         gss_buffer_desc input_token, output_token;
 484         int conf_state;
 485         ssize_t sig_length = 0;
 486
 487         input_token.length = length;
 488         input_token.value = data;
 489
 490         maj_stat = gss_wrap(&min_stat,
 491                             gensec_gssapi_state->gssapi_context,
 492                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 493                             GSS_C_QOP_DEFAULT,
 494                             &input_token,
 495                             &conf_state,
 496                             &output_token);
 497         if (GSS_ERROR(maj_stat)) {
 498                 DEBUG(1, ("GSS Wrap failed: %s\n",
 499                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 500                 return NT_STATUS_ACCESS_DENIED;
 501         }
 502
 503         if (output_token.length < length) {
 504                 return NT_STATUS_INTERNAL_ERROR;
 505         }
 506
 507         sig_length = 45;
 508
 509         memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);
 510         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 511
 512         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 513         dump_data_pw("gensec_gssapi_seal_packet: clear\n", data, length);
 514         dump_data_pw("gensec_gssapi_seal_packet: sealed\n", ((uint8_t *)output_token.value) + sig_length, output_token.length - sig_length);
 515
 516         gss_release_buffer(&min_stat, &output_token);
 517
 518         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 519             && !conf_state) {
 520                 return NT_STATUS_ACCESS_DENIED;
 521         }
 522         return NT_STATUS_OK;
 523 }
 524
 525 static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_security,
 526                                             TALLOC_CTX *mem_ctx,
 527                                             uint8_t *data, size_t length,
 528                                             const uint8_t *whole_pdu, size_t pdu_length,
 529                                             const DATA_BLOB *sig)
 530 {
 531         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 532         OM_uint32 maj_stat, min_stat;
 533         gss_buffer_desc input_token, output_token;
 534         int conf_state;
 535         gss_qop_t qop_state;
 536         DATA_BLOB in;
 537
 538         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 539
 540         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 541
 542         memcpy(in.data, sig->data, sig->length);
 543         memcpy(in.data + sig->length, data, length);
 544
 545         input_token.length = in.length;
 546         input_token.value = in.data;
 547
 548         maj_stat = gss_unwrap(&min_stat,
 549                               gensec_gssapi_state->gssapi_context,
 550                               &input_token,
 551                               &output_token,
 552                               &conf_state,
 553                               &qop_state);
 554         if (GSS_ERROR(maj_stat)) {
 555                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 556                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 557                 return NT_STATUS_ACCESS_DENIED;
 558         }
 559
 560         if (output_token.length != length) {
 561                 return NT_STATUS_INTERNAL_ERROR;
 562         }
 563
 564         memcpy(data, output_token.value, length);
 565
 566         gss_release_buffer(&min_stat, &output_token);
 567
 568         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 569             && !conf_state) {
 570                 return NT_STATUS_ACCESS_DENIED;
 571         }
 572         return NT_STATUS_OK;
 573 }
 574
 575 static NTSTATUS gensec_gssapi_sign_packet(struct gensec_security *gensec_security,
 576                                           TALLOC_CTX *mem_ctx,
 577                                           const uint8_t *data, size_t length,
 578                                           const uint8_t *whole_pdu, size_t pdu_length,
 579                                           DATA_BLOB *sig)
 580 {
 581         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 582         OM_uint32 maj_stat, min_stat;
 583         gss_buffer_desc input_token, output_token;
 584         int conf_state;
 585         ssize_t sig_length = 0;
 586
 587         input_token.length = length;
 588         input_token.value = discard_const_p(uint8_t *, data);
 589
 590         maj_stat = gss_wrap(&min_stat,
 591                             gensec_gssapi_state->gssapi_context,
 592                             0,
 593                             GSS_C_QOP_DEFAULT,
 594                             &input_token,
 595                             &conf_state,
 596                             &output_token);
 597         if (GSS_ERROR(maj_stat)) {
 598                 DEBUG(1, ("GSS Wrap failed: %s\n",
 599                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 600                 return NT_STATUS_ACCESS_DENIED;
 601         }
 602
 603         if (output_token.length < length) {
 604                 return NT_STATUS_INTERNAL_ERROR;
 605         }
 606
 607         sig_length = 45;
 608
 609         /*memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);*/
 610         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 611
 612         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 613
 614         gss_release_buffer(&min_stat, &output_token);
 615
 616         return NT_STATUS_OK;
 617 }
 618
 619 static NTSTATUS gensec_gssapi_check_packet(struct gensec_security *gensec_security,
 620                                            TALLOC_CTX *mem_ctx,
 621                                            const uint8_t *data, size_t length,
 622                                            const uint8_t *whole_pdu, size_t pdu_length,
 623                                            const DATA_BLOB *sig)
 624 {
 625         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 626         OM_uint32 maj_stat, min_stat;
 627         gss_buffer_desc input_token, output_token;
 628         int conf_state;
 629         gss_qop_t qop_state;
 630         DATA_BLOB in;
 631
 632         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 633
 634         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 635
 636         memcpy(in.data, sig->data, sig->length);
 637         memcpy(in.data + sig->length, data, length);
 638
 639         input_token.length = in.length;
 640         input_token.value = in.data;
 641
 642         maj_stat = gss_unwrap(&min_stat,
 643                               gensec_gssapi_state->gssapi_context,
 644                               &input_token,
 645                               &output_token,
 646                               &conf_state,
 647                               &qop_state);
 648         if (GSS_ERROR(maj_stat)) {
 649                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 650                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 651                 return NT_STATUS_ACCESS_DENIED;
 652         }
 653
 654         if (output_token.length != length) {
 655                 return NT_STATUS_INTERNAL_ERROR;
 656         }
 657
 658         gss_release_buffer(&min_stat, &output_token);
 659
 660         return NT_STATUS_OK;
 661 }
 662
 663 static BOOL gensec_gssapi_have_feature(struct gensec_security *gensec_security,
 664                                        uint32_t feature)
 665 {
 666         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 667         if (feature & GENSEC_FEATURE_SIGN) {
 668                 return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
 669         }
 670         if (feature & GENSEC_FEATURE_SEAL) {
 671                 return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
 672         }
 673         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 674 #ifdef HAVE_GSSKRB5_GET_INITIATOR_SUBKEY
 675                 if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 676                     && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements, gensec_gssapi_state->gss_oid->length) == 0)) {
 677                         return True;
 678                 }
 679 #endif
 680         }
 681         return False;
 682 }
 683
 684 static NTSTATUS gensec_gssapi_session_key(struct gensec_security *gensec_security,
 685                                           DATA_BLOB *session_key)
 686 {
 687         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 688
 689         if (gensec_gssapi_state->session_key.data) {
 690                 *session_key = gensec_gssapi_state->session_key;
 691                 return NT_STATUS_OK;
 692         }
 693
 694 #ifdef HAVE_GSSKRB5_GET_INITIATOR_SUBKEY
 695         /* Ensure we only call this for GSSAPI/krb5, otherwise things could get very ugly */
 696         if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 697             && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 698                        gensec_gssapi_state->gss_oid->length) == 0)) {
 699                 OM_uint32 maj_stat, min_stat;
 700                 gss_buffer_desc skey;
 701
 702                 maj_stat = gsskrb5_get_initiator_subkey(&min_stat,
 703                                                         gensec_gssapi_state->gssapi_context,
 704                                                         &skey);
 705
 706                 if (maj_stat == 0) {
 707                         DEBUG(10, ("Got KRB5 session key of length %d\n",  skey.length));
 708                         gensec_gssapi_state->session_key = data_blob_talloc(gensec_gssapi_state,
 709                                                                             skey.value, skey.length);
 710                         *session_key = gensec_gssapi_state->session_key;
 711                         dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 712
 713                         gss_release_buffer(&min_stat, &skey);
 714                         return NT_STATUS_OK;
 715                 }
 716                 return NT_STATUS_NO_USER_SESSION_KEY;
 717         }
 718 #endif
 719
 720         DEBUG(1, ("NO session key for this mech\n"));
 721         return NT_STATUS_NO_USER_SESSION_KEY;
 722 }
 723
 724 static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_security,
 725                                          struct auth_session_info **_session_info)
 726 {
 727         NTSTATUS nt_status;
 728         TALLOC_CTX *mem_ctx;
 729         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 730         struct auth_serversupplied_info *server_info = NULL;
 731         struct auth_session_info *session_info = NULL;
 732         struct PAC_LOGON_INFO *logon_info;
 733         char *p;
 734         char *principal;
 735         const char *account_name;
 736         const char *realm;
 737         OM_uint32 maj_stat, min_stat;
 738         gss_buffer_desc name_token;
 739         gss_buffer_desc pac;
 740
 741         mem_ctx = talloc_named(gensec_gssapi_state, 0, "gensec_gssapi_session_info context");
 742         NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
 743
 744         maj_stat = gss_display_name (&min_stat,
 745                                      gensec_gssapi_state->client_name,
 746                                      &name_token,
 747                                      NULL);
 748         if (maj_stat) {
 749                 return NT_STATUS_FOOBAR;
 750         }
 751
 752         principal = talloc_strndup(mem_ctx, name_token.value, name_token.length);
 753
 754         gss_release_buffer(&min_stat, &name_token);
 755
 756         if (!principal) {
 757                 talloc_free(mem_ctx);
 758                 return NT_STATUS_NO_MEMORY;
 759         }
 760
 761         p = strchr(principal, '@');
 762         if (p) {
 763                 *p = '\0';
 764                 p++;
 765                 realm = p;
 766         } else {
 767                 realm = lp_realm();
 768         }
 769         account_name = principal;
 770
 771         maj_stat = gsskrb5_extract_authz_data_from_sec_context(&min_stat,
 772                                                                gensec_gssapi_state->gssapi_context,
 773                                                                1,
 774                                                                &pac);
 775
 776         if (maj_stat == 0) {
 777                 DATA_BLOB pac_blob = data_blob_talloc(mem_ctx, pac.value, pac.length);
 778                 pac_blob = unwrap_pac(mem_ctx, &pac_blob);
 779                 gss_release_buffer(&min_stat, &pac);
 780
 781                 /* decode and verify the pac */
 782                 nt_status = kerberos_decode_pac(mem_ctx, &logon_info, pac_blob,
 783                                                 gensec_gssapi_state->smb_krb5_context);
 784
 785                 if (NT_STATUS_IS_OK(nt_status)) {
 786                         union netr_Validation validation;
 787                         validation.sam3 = &logon_info->info3;
 788                         nt_status = make_server_info_netlogon_validation(gensec_gssapi_state,
 789                                                                          account_name,
 790                                                                          3, &validation,
 791                                                                          &server_info);
 792                         if (!NT_STATUS_IS_OK(nt_status)) {
 793                                 talloc_free(mem_ctx);
 794                                 return nt_status;
 795                         }
 796                 } else {
 797                         maj_stat = 1;
 798                 }
 799         }
 800
 801         if (maj_stat) {
 802                 /* IF we have the PAC - otherwise we need to get this
 803                  * data from elsewere - local ldb, or (TODO) lookup of some
 804                  * kind...
 805                  *
 806                  * when heimdal can generate the PAC, we should fail if there's
 807                  * no PAC present
 808                  */
 809
 810                 DATA_BLOB user_sess_key = data_blob(NULL, 0);
 811                 DATA_BLOB lm_sess_key = data_blob(NULL, 0);
 812                 /* TODO: should we pass the krb5 session key in here? */
 813                 nt_status = sam_get_server_info(mem_ctx, account_name, realm,
 814                                                 user_sess_key, lm_sess_key,
 815                                                 &server_info);
 816                 if (!NT_STATUS_IS_OK(nt_status)) {
 817                         talloc_free(mem_ctx);
 818                         return nt_status;
 819                 }
 820         }
 821
 822         /* references the server_info into the session_info */
 823         nt_status = auth_generate_session_info(gensec_gssapi_state, server_info, &session_info);
 824         talloc_free(server_info);
 825         NT_STATUS_NOT_OK_RETURN(nt_status);
 826
 827         nt_status = gensec_gssapi_session_key(gensec_security, &session_info->session_key);
 828         NT_STATUS_NOT_OK_RETURN(nt_status);
 829
 830         *_session_info = session_info;
 831
 832         return NT_STATUS_OK;
 833 }
 834
 835 static const char *gensec_krb5_oids[] = {
 836         GENSEC_OID_KERBEROS5,
 837         GENSEC_OID_KERBEROS5_OLD,
 838         NULL
 839 };
 840
 841 /* As a server, this could in theory accept any GSSAPI mech */
 842 static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
 843         .name           = "gssapi_krb5",
 844         .oid            = gensec_krb5_oids,
 845         .client_start   = gensec_gssapi_client_start,
 846         .server_start   = gensec_gssapi_server_start,
 847         .magic          = gensec_gssapi_magic,
 848         .update         = gensec_gssapi_update,
 849         .session_key    = gensec_gssapi_session_key,
 850         .session_info   = gensec_gssapi_session_info,
 851         .sig_size       = gensec_gssapi_sig_size,
 852         .sign_packet    = gensec_gssapi_sign_packet,
 853         .check_packet   = gensec_gssapi_check_packet,
 854         .seal_packet    = gensec_gssapi_seal_packet,
 855         .unseal_packet  = gensec_gssapi_unseal_packet,
 856         .wrap           = gensec_gssapi_wrap,
 857         .unwrap         = gensec_gssapi_unwrap,
 858         .have_feature   = gensec_gssapi_have_feature,
 859         .enabled        = False
 860 };
 861
 862 NTSTATUS gensec_gssapi_init(void)
 863 {
 864         NTSTATUS ret;
 865
 866         ret = gensec_register(&gensec_gssapi_krb5_security_ops);
 867         if (!NT_STATUS_IS_OK(ret)) {
 868                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 869                         gensec_gssapi_krb5_security_ops.name));
 870                 return ret;
 871         }
 872
 873         return ret;
 874 }