source/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 struct gensec_gssapi_state {
  33         gss_ctx_id_t gssapi_context;
  34         struct gss_channel_bindings_struct *input_chan_bindings;
  35         gss_name_t server_name;
  36         gss_name_t client_name;
  37         OM_uint32 want_flags, got_flags;
  38         const gss_OID_desc *gss_oid;
  39
  40         DATA_BLOB session_key;
  41         DATA_BLOB pac;
  42
  43         struct smb_krb5_context *smb_krb5_context;
  44         krb5_ccache ccache;
  45         const char *ccache_name;
  46         krb5_keytab keytab;
  47
  48         gss_cred_id_t cred;
  49 };
  50
  51 static char *gssapi_error_string(TALLOC_CTX *mem_ctx,
  52                                  OM_uint32 maj_stat, OM_uint32 min_stat)
  53 {
  54         OM_uint32 disp_min_stat, disp_maj_stat;
  55         gss_buffer_desc maj_error_message;
  56         gss_buffer_desc min_error_message;
  57         OM_uint32 msg_ctx = 0;
  58
  59         char *ret;
  60
  61         maj_error_message.value = NULL;
  62         min_error_message.value = NULL;
  63
  64         disp_maj_stat = gss_display_status(&disp_min_stat, maj_stat, GSS_C_GSS_CODE,
  65                            GSS_C_NULL_OID, &msg_ctx, &maj_error_message);
  66         disp_maj_stat = gss_display_status(&disp_min_stat, min_stat, GSS_C_MECH_CODE,
  67                            GSS_C_NULL_OID, &msg_ctx, &min_error_message);
  68         ret = talloc_asprintf(mem_ctx, "%s: %s", (char *)maj_error_message.value, (char *)min_error_message.value);
  69
  70         gss_release_buffer(&disp_min_stat, &maj_error_message);
  71         gss_release_buffer(&disp_min_stat, &min_error_message);
  72
  73         return ret;
  74 }
  75
  76
  77 static int gensec_gssapi_destory(void *ptr)
  78 {
  79         struct gensec_gssapi_state *gensec_gssapi_state = ptr;
  80         OM_uint32 maj_stat, min_stat;
  81
  82         if (gensec_gssapi_state->cred != GSS_C_NO_CREDENTIAL) {
  83                 maj_stat = gss_release_cred(&min_stat,
  84                                             &gensec_gssapi_state->cred);
  85         }
  86
  87         if (gensec_gssapi_state->gssapi_context != GSS_C_NO_CONTEXT) {
  88                 maj_stat = gss_delete_sec_context (&min_stat,
  89                                                    &gensec_gssapi_state->gssapi_context,
  90                                                    GSS_C_NO_BUFFER);
  91         }
  92
  93         if (gensec_gssapi_state->server_name != GSS_C_NO_NAME) {
  94                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->server_name);
  95         }
  96         if (gensec_gssapi_state->client_name != GSS_C_NO_NAME) {
  97                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->client_name);
  98         }
  99         return 0;
 100 }
 101
 102 static NTSTATUS gensec_gssapi_start(struct gensec_security *gensec_security)
 103 {
 104         struct gensec_gssapi_state *gensec_gssapi_state;
 105         krb5_error_code ret;
 106
 107         gensec_gssapi_state = talloc(gensec_security, struct gensec_gssapi_state);
 108         if (!gensec_gssapi_state) {
 109                 return NT_STATUS_NO_MEMORY;
 110         }
 111
 112         gensec_security->private_data = gensec_gssapi_state;
 113
 114         gensec_gssapi_state->gssapi_context = GSS_C_NO_CONTEXT;
 115         gensec_gssapi_state->server_name = GSS_C_NO_NAME;
 116         gensec_gssapi_state->client_name = GSS_C_NO_NAME;
 117
 118         /* TODO: Fill in channel bindings */
 119         gensec_gssapi_state->input_chan_bindings = GSS_C_NO_CHANNEL_BINDINGS;
 120
 121         gensec_gssapi_state->want_flags = 0;
 122         gensec_gssapi_state->got_flags = 0;
 123
 124         gensec_gssapi_state->session_key = data_blob(NULL, 0);
 125         gensec_gssapi_state->pac = data_blob(NULL, 0);
 126
 127         gensec_gssapi_state->cred = GSS_C_NO_CREDENTIAL;
 128
 129         talloc_set_destructor(gensec_gssapi_state, gensec_gssapi_destory);
 130
 131         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 132                 gensec_gssapi_state->want_flags |= GSS_C_INTEG_FLAG;
 133         }
 134         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 135                 gensec_gssapi_state->want_flags |= GSS_C_CONF_FLAG;
 136         }
 137         if (gensec_security->want_features & GENSEC_FEATURE_DCE_STYLE) {
 138                 gensec_gssapi_state->want_flags |= GSS_C_DCE_STYLE;
 139         }
 140
 141         gensec_gssapi_state->gss_oid = gss_mech_krb5;
 142
 143         ret = smb_krb5_init_context(gensec_gssapi_state,
 144                                     &gensec_gssapi_state->smb_krb5_context);
 145         if (ret) {
 146                 DEBUG(1,("gensec_krb5_start: krb5_init_context failed (%s)\n",
 147                          error_message(ret)));
 148                 return NT_STATUS_INTERNAL_ERROR;
 149         }
 150         return NT_STATUS_OK;
 151 }
 152
 153 static NTSTATUS gensec_gssapi_server_start(struct gensec_security *gensec_security)
 154 {
 155         NTSTATUS nt_status;
 156         OM_uint32 maj_stat, min_stat;
 157         gss_buffer_desc name_token;
 158         struct gensec_gssapi_state *gensec_gssapi_state;
 159         struct cli_credentials *machine_account;
 160
 161         nt_status = gensec_gssapi_start(gensec_security);
 162         if (!NT_STATUS_IS_OK(nt_status)) {
 163                 return nt_status;
 164         }
 165
 166         gensec_gssapi_state = gensec_security->private_data;
 167
 168         machine_account = cli_credentials_init(gensec_gssapi_state);
 169         cli_credentials_set_conf(machine_account);
 170         nt_status = cli_credentials_set_machine_account(machine_account);
 171
 172         if (!NT_STATUS_IS_OK(nt_status)) {
 173                 DEBUG(3, ("Could not obtain machine account credentials from the local database\n"));
 174                 talloc_free(machine_account);
 175                 return nt_status;
 176         } else {
 177                 nt_status = create_memory_keytab(gensec_gssapi_state,
 178                                                  machine_account,
 179                                                  gensec_gssapi_state->smb_krb5_context,
 180                                                  &gensec_gssapi_state->keytab);
 181                 if (!NT_STATUS_IS_OK(nt_status)) {
 182                         DEBUG(3, ("Could not create memory keytab!\n"));
 183                         talloc_free(machine_account);
 184                         return nt_status;
 185                 }
 186         }
 187
 188         name_token.value = cli_credentials_get_principal(machine_account,
 189                                                          machine_account);
 190         name_token.length = strlen(name_token.value);
 191
 192         maj_stat = gss_import_name (&min_stat,
 193                                     &name_token,
 194                                     GSS_C_NT_USER_NAME,
 195                                     &gensec_gssapi_state->server_name);
 196         talloc_free(machine_account);
 197
 198         if (maj_stat) {
 199                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 200                           (char *)name_token.value,
 201                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 202                 return NT_STATUS_UNSUCCESSFUL;
 203         }
 204
 205         maj_stat = gsskrb5_acquire_cred(&min_stat,
 206                                         gensec_gssapi_state->keytab, NULL,
 207                                         gensec_gssapi_state->server_name,
 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         struct ccache_container *ccache;
 229         krb5_error_code ret;
 230         NTSTATUS nt_status;
 231         gss_buffer_desc name_token;
 232         OM_uint32 maj_stat, min_stat;
 233         const char *hostname = gensec_get_target_hostname(gensec_security);
 234
 235         if (!hostname) {
 236                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 237                 return NT_STATUS_INVALID_PARAMETER;
 238         }
 239         if (is_ipaddress(hostname)) {
 240                 DEBUG(2, ("Cannot do GSSAPI to a IP address"));
 241                 return NT_STATUS_INVALID_PARAMETER;
 242         }
 243
 244         nt_status = gensec_gssapi_start(gensec_security);
 245         if (!NT_STATUS_IS_OK(nt_status)) {
 246                 return nt_status;
 247         }
 248
 249         gensec_gssapi_state = gensec_security->private_data;
 250
 251         name_token.value = talloc_asprintf(gensec_gssapi_state, "%s@%s",
 252                                            gensec_get_target_service(gensec_security),
 253                                            hostname);
 254         name_token.length = strlen(name_token.value);
 255
 256         maj_stat = gss_import_name (&min_stat,
 257                                     &name_token,
 258                                     GSS_C_NT_HOSTBASED_SERVICE,
 259                                     &gensec_gssapi_state->server_name);
 260         if (maj_stat) {
 261                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 262                           (char *)name_token.value,
 263                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 264                 return NT_STATUS_INVALID_PARAMETER;
 265         }
 266
 267         ret = cli_credentials_get_ccache(creds,
 268                                          &ccache);
 269         if (ret) {
 270                 DEBUG(1, ("Failed to get CCACHE for gensec_gssapi: %s\n", error_message(ret)));
 271                 return NT_STATUS_UNSUCCESSFUL;
 272         }
 273
 274         name_token.value = cli_credentials_get_principal(creds,
 275                                                          gensec_gssapi_state);
 276         name_token.length = strlen(name_token.value);
 277
 278         maj_stat = gss_import_name (&min_stat,
 279                                     &name_token,
 280                                     GSS_C_NT_USER_NAME,
 281                                     &gensec_gssapi_state->client_name);
 282         if (maj_stat) {
 283                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 284                           (char *)name_token.value,
 285                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 286                 return NT_STATUS_UNSUCCESSFUL;
 287         }
 288
 289         maj_stat = gsskrb5_acquire_cred(&min_stat,
 290                                         NULL, ccache->ccache,
 291                                         gensec_gssapi_state->client_name,
 292                                         GSS_C_INDEFINITE,
 293                                         GSS_C_NULL_OID_SET,
 294                                         GSS_C_INITIATE,
 295                                         &gensec_gssapi_state->cred,
 296                                         NULL,
 297                                         NULL);
 298         if (maj_stat) {
 299                 DEBUG(1, ("Aquiring initiator credentails failed: %s\n",
 300                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 301                 return NT_STATUS_UNSUCCESSFUL;
 302         }
 303
 304         return NT_STATUS_OK;
 305 }
 306
 307
 308 /**
 309  * Check if the packet is one for this mechansim
 310  *
 311  * @param gensec_security GENSEC state
 312  * @param in The request, as a DATA_BLOB
 313  * @return Error, INVALID_PARAMETER if it's not a packet for us
 314  *                or NT_STATUS_OK if the packet is ok.
 315  */
 316
 317 static NTSTATUS gensec_gssapi_magic(struct gensec_security *gensec_security,
 318                                     const DATA_BLOB *in)
 319 {
 320         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 321                 return NT_STATUS_OK;
 322         } else {
 323                 return NT_STATUS_INVALID_PARAMETER;
 324         }
 325 }
 326
 327
 328 /**
 329  * Next state function for the GSSAPI GENSEC mechanism
 330  *
 331  * @param gensec_gssapi_state GSSAPI State
 332  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 333  * @param in The request, as a DATA_BLOB
 334  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 335  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 336  *                or NT_STATUS_OK if the user is authenticated.
 337  */
 338
 339 static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 340                                    TALLOC_CTX *out_mem_ctx,
 341                                    const DATA_BLOB in, DATA_BLOB *out)
 342 {
 343         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 344         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 345         OM_uint32 maj_stat, min_stat;
 346         OM_uint32 min_stat2;
 347         gss_buffer_desc input_token, output_token;
 348         gss_OID gss_oid_p;
 349         input_token.length = in.length;
 350         input_token.value = in.data;
 351
 352         switch (gensec_security->gensec_role) {
 353         case GENSEC_CLIENT:
 354         {
 355                 maj_stat = gss_init_sec_context(&min_stat,
 356                                                 gensec_gssapi_state->cred,
 357                                                 &gensec_gssapi_state->gssapi_context,
 358                                                 gensec_gssapi_state->server_name,
 359                                                 discard_const_p(gss_OID_desc, gensec_gssapi_state->gss_oid),
 360                                                 gensec_gssapi_state->want_flags,
 361                                                 0,
 362                                                 gensec_gssapi_state->input_chan_bindings,
 363                                                 &input_token,
 364                                                 NULL,
 365                                                 &output_token,
 366                                                 &gensec_gssapi_state->got_flags, /* ret flags */
 367                                                 NULL);
 368                 break;
 369         }
 370         case GENSEC_SERVER:
 371         {
 372                 maj_stat = gss_accept_sec_context(&min_stat,
 373                                                   &gensec_gssapi_state->gssapi_context,
 374                                                   gensec_gssapi_state->cred,
 375                                                   &input_token,
 376                                                   gensec_gssapi_state->input_chan_bindings,
 377                                                   &gensec_gssapi_state->client_name,
 378                                                   &gss_oid_p,
 379                                                   &output_token,
 380                                                   &gensec_gssapi_state->got_flags,
 381                                                   NULL,
 382                                                   NULL);
 383                 gensec_gssapi_state->gss_oid = gss_oid_p;
 384                 break;
 385         }
 386         default:
 387                 return NT_STATUS_INVALID_PARAMETER;
 388
 389         }
 390
 391         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 392         gss_release_buffer(&min_stat2, &output_token);
 393
 394         if (maj_stat == GSS_S_COMPLETE) {
 395                 return NT_STATUS_OK;
 396         } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 397                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 398         } else {
 399                 if (maj_stat == GSS_S_FAILURE
 400                     && (min_stat == KRB5KRB_AP_ERR_BADVERSION || min_stat == KRB5KRB_AP_ERR_MSG_TYPE)) {
 401                         /* garbage input, possibly from the auto-mech detection */
 402                         return NT_STATUS_INVALID_PARAMETER;
 403                 }
 404                 DEBUG(1, ("GSS Update failed: %s\n",
 405                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 406                 return nt_status;
 407         }
 408 }
 409
 410 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 411                                    TALLOC_CTX *mem_ctx,
 412                                    const DATA_BLOB *in,
 413                                    DATA_BLOB *out)
 414 {
 415         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 416         OM_uint32 maj_stat, min_stat;
 417         gss_buffer_desc input_token, output_token;
 418         int conf_state;
 419         input_token.length = in->length;
 420         input_token.value = in->data;
 421
 422         maj_stat = gss_wrap(&min_stat,
 423                             gensec_gssapi_state->gssapi_context,
 424                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 425                             GSS_C_QOP_DEFAULT,
 426                             &input_token,
 427                             &conf_state,
 428                             &output_token);
 429         if (GSS_ERROR(maj_stat)) {
 430                 DEBUG(1, ("GSS Wrap failed: %s\n",
 431                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 432                 return NT_STATUS_ACCESS_DENIED;
 433         }
 434         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 435
 436         gss_release_buffer(&min_stat, &output_token);
 437
 438         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 439             && !conf_state) {
 440                 return NT_STATUS_ACCESS_DENIED;
 441         }
 442         return NT_STATUS_OK;
 443 }
 444
 445 static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 446                                      TALLOC_CTX *mem_ctx,
 447                                      const DATA_BLOB *in,
 448                                      DATA_BLOB *out)
 449 {
 450         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 451         OM_uint32 maj_stat, min_stat;
 452         gss_buffer_desc input_token, output_token;
 453         int conf_state;
 454         gss_qop_t qop_state;
 455         input_token.length = in->length;
 456         input_token.value = in->data;
 457
 458         maj_stat = gss_unwrap(&min_stat,
 459                               gensec_gssapi_state->gssapi_context,
 460                               &input_token,
 461                               &output_token,
 462                               &conf_state,
 463                               &qop_state);
 464         if (GSS_ERROR(maj_stat)) {
 465                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 466                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 467                 return NT_STATUS_ACCESS_DENIED;
 468         }
 469         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 470
 471         gss_release_buffer(&min_stat, &output_token);
 472
 473         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 474             && !conf_state) {
 475                 return NT_STATUS_ACCESS_DENIED;
 476         }
 477         return NT_STATUS_OK;
 478 }
 479
 480 static size_t gensec_gssapi_sig_size(struct gensec_security *gensec_security)
 481 {
 482         /* not const but work for DCERPC packets and arcfour */
 483         return 45;
 484 }
 485
 486 static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_security,
 487                                           TALLOC_CTX *mem_ctx,
 488                                           uint8_t *data, size_t length,
 489                                           const uint8_t *whole_pdu, size_t pdu_length,
 490                                           DATA_BLOB *sig)
 491 {
 492         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 493         OM_uint32 maj_stat, min_stat;
 494         gss_buffer_desc input_token, output_token;
 495         int conf_state;
 496         ssize_t sig_length = 0;
 497
 498         input_token.length = length;
 499         input_token.value = data;
 500
 501         maj_stat = gss_wrap(&min_stat,
 502                             gensec_gssapi_state->gssapi_context,
 503                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 504                             GSS_C_QOP_DEFAULT,
 505                             &input_token,
 506                             &conf_state,
 507                             &output_token);
 508         if (GSS_ERROR(maj_stat)) {
 509                 DEBUG(1, ("GSS Wrap failed: %s\n",
 510                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 511                 return NT_STATUS_ACCESS_DENIED;
 512         }
 513
 514         if (output_token.length < length) {
 515                 return NT_STATUS_INTERNAL_ERROR;
 516         }
 517
 518         sig_length = 45;
 519
 520         memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);
 521         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 522
 523         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 524         dump_data_pw("gensec_gssapi_seal_packet: clear\n", data, length);
 525         dump_data_pw("gensec_gssapi_seal_packet: sealed\n", ((uint8_t *)output_token.value) + sig_length, output_token.length - sig_length);
 526
 527         gss_release_buffer(&min_stat, &output_token);
 528
 529         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 530             && !conf_state) {
 531                 return NT_STATUS_ACCESS_DENIED;
 532         }
 533         return NT_STATUS_OK;
 534 }
 535
 536 static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_security,
 537                                             TALLOC_CTX *mem_ctx,
 538                                             uint8_t *data, size_t length,
 539                                             const uint8_t *whole_pdu, size_t pdu_length,
 540                                             const DATA_BLOB *sig)
 541 {
 542         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 543         OM_uint32 maj_stat, min_stat;
 544         gss_buffer_desc input_token, output_token;
 545         int conf_state;
 546         gss_qop_t qop_state;
 547         DATA_BLOB in;
 548
 549         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 550
 551         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 552
 553         memcpy(in.data, sig->data, sig->length);
 554         memcpy(in.data + sig->length, data, length);
 555
 556         input_token.length = in.length;
 557         input_token.value = in.data;
 558
 559         maj_stat = gss_unwrap(&min_stat,
 560                               gensec_gssapi_state->gssapi_context,
 561                               &input_token,
 562                               &output_token,
 563                               &conf_state,
 564                               &qop_state);
 565         if (GSS_ERROR(maj_stat)) {
 566                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 567                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 568                 return NT_STATUS_ACCESS_DENIED;
 569         }
 570
 571         if (output_token.length != length) {
 572                 return NT_STATUS_INTERNAL_ERROR;
 573         }
 574
 575         memcpy(data, output_token.value, length);
 576
 577         gss_release_buffer(&min_stat, &output_token);
 578
 579         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 580             && !conf_state) {
 581                 return NT_STATUS_ACCESS_DENIED;
 582         }
 583         return NT_STATUS_OK;
 584 }
 585
 586 static NTSTATUS gensec_gssapi_sign_packet(struct gensec_security *gensec_security,
 587                                           TALLOC_CTX *mem_ctx,
 588                                           const uint8_t *data, size_t length,
 589                                           const uint8_t *whole_pdu, size_t pdu_length,
 590                                           DATA_BLOB *sig)
 591 {
 592         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 593         OM_uint32 maj_stat, min_stat;
 594         gss_buffer_desc input_token, output_token;
 595         int conf_state;
 596         ssize_t sig_length = 0;
 597
 598         input_token.length = length;
 599         input_token.value = discard_const_p(uint8_t *, data);
 600
 601         maj_stat = gss_wrap(&min_stat,
 602                             gensec_gssapi_state->gssapi_context,
 603                             0,
 604                             GSS_C_QOP_DEFAULT,
 605                             &input_token,
 606                             &conf_state,
 607                             &output_token);
 608         if (GSS_ERROR(maj_stat)) {
 609                 DEBUG(1, ("GSS Wrap failed: %s\n",
 610                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 611                 return NT_STATUS_ACCESS_DENIED;
 612         }
 613
 614         if (output_token.length < length) {
 615                 return NT_STATUS_INTERNAL_ERROR;
 616         }
 617
 618         sig_length = 45;
 619
 620         /*memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);*/
 621         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 622
 623         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 624
 625         gss_release_buffer(&min_stat, &output_token);
 626
 627         return NT_STATUS_OK;
 628 }
 629
 630 static NTSTATUS gensec_gssapi_check_packet(struct gensec_security *gensec_security,
 631                                            TALLOC_CTX *mem_ctx,
 632                                            const uint8_t *data, size_t length,
 633                                            const uint8_t *whole_pdu, size_t pdu_length,
 634                                            const DATA_BLOB *sig)
 635 {
 636         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 637         OM_uint32 maj_stat, min_stat;
 638         gss_buffer_desc input_token, output_token;
 639         int conf_state;
 640         gss_qop_t qop_state;
 641         DATA_BLOB in;
 642
 643         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 644
 645         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 646
 647         memcpy(in.data, sig->data, sig->length);
 648         memcpy(in.data + sig->length, data, length);
 649
 650         input_token.length = in.length;
 651         input_token.value = in.data;
 652
 653         maj_stat = gss_unwrap(&min_stat,
 654                               gensec_gssapi_state->gssapi_context,
 655                               &input_token,
 656                               &output_token,
 657                               &conf_state,
 658                               &qop_state);
 659         if (GSS_ERROR(maj_stat)) {
 660                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 661                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 662                 return NT_STATUS_ACCESS_DENIED;
 663         }
 664
 665         if (output_token.length != length) {
 666                 return NT_STATUS_INTERNAL_ERROR;
 667         }
 668
 669         gss_release_buffer(&min_stat, &output_token);
 670
 671         return NT_STATUS_OK;
 672 }
 673
 674 static BOOL gensec_gssapi_have_feature(struct gensec_security *gensec_security,
 675                                        uint32_t feature)
 676 {
 677         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 678         if (feature & GENSEC_FEATURE_SIGN) {
 679                 return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
 680         }
 681         if (feature & GENSEC_FEATURE_SEAL) {
 682                 return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
 683         }
 684         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 685                 if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 686                     && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements, gensec_gssapi_state->gss_oid->length) == 0)) {
 687                         return True;
 688                 }
 689         }
 690         if (feature & GENSEC_FEATURE_DCE_STYLE) {
 691                 return True;
 692         }
 693         if (feature & GENSEC_FEATURE_ASYNC_REPLIES) {
 694                 return True;
 695         }
 696         return False;
 697 }
 698
 699 static NTSTATUS gensec_gssapi_session_key(struct gensec_security *gensec_security,
 700                                           DATA_BLOB *session_key)
 701 {
 702         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 703
 704         if (gensec_gssapi_state->session_key.data) {
 705                 *session_key = gensec_gssapi_state->session_key;
 706                 return NT_STATUS_OK;
 707         }
 708
 709         /* Ensure we only call this for GSSAPI/krb5, otherwise things could get very ugly */
 710         if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 711             && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 712                        gensec_gssapi_state->gss_oid->length) == 0)) {
 713                 OM_uint32 maj_stat, min_stat;
 714                 gss_buffer_desc skey;
 715
 716                 maj_stat = gsskrb5_get_initiator_subkey(&min_stat,
 717                                                         gensec_gssapi_state->gssapi_context,
 718                                                         &skey);
 719
 720                 if (maj_stat == 0) {
 721                         DEBUG(10, ("Got KRB5 session key of length %d\n",
 722                                    (int)skey.length));
 723                         gensec_gssapi_state->session_key = data_blob_talloc(gensec_gssapi_state,
 724                                                                             skey.value, skey.length);
 725                         *session_key = gensec_gssapi_state->session_key;
 726                         dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 727
 728                         gss_release_buffer(&min_stat, &skey);
 729                         return NT_STATUS_OK;
 730                 }
 731                 return NT_STATUS_NO_USER_SESSION_KEY;
 732         }
 733
 734         DEBUG(1, ("NO session key for this mech\n"));
 735         return NT_STATUS_NO_USER_SESSION_KEY;
 736 }
 737
 738 static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_security,
 739                                          struct auth_session_info **_session_info)
 740 {
 741         NTSTATUS nt_status;
 742         TALLOC_CTX *mem_ctx;
 743         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 744         struct auth_serversupplied_info *server_info = NULL;
 745         struct auth_session_info *session_info = NULL;
 746         struct PAC_LOGON_INFO *logon_info;
 747         char *p;
 748         char *principal;
 749         const char *account_name;
 750         const char *realm;
 751         OM_uint32 maj_stat, min_stat;
 752         gss_buffer_desc name_token;
 753         gss_buffer_desc pac;
 754         krb5_keyblock *keyblock;
 755
 756         mem_ctx = talloc_named(gensec_gssapi_state, 0, "gensec_gssapi_session_info context");
 757         NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
 758
 759         maj_stat = gss_display_name (&min_stat,
 760                                      gensec_gssapi_state->client_name,
 761                                      &name_token,
 762                                      NULL);
 763         if (maj_stat) {
 764                 return NT_STATUS_FOOBAR;
 765         }
 766
 767         principal = talloc_strndup(mem_ctx, name_token.value, name_token.length);
 768
 769         gss_release_buffer(&min_stat, &name_token);
 770
 771         if (!principal) {
 772                 talloc_free(mem_ctx);
 773                 return NT_STATUS_NO_MEMORY;
 774         }
 775
 776         p = strchr(principal, '@');
 777         if (p) {
 778                 *p = '\0';
 779                 p++;
 780                 realm = p;
 781         } else {
 782                 realm = lp_realm();
 783         }
 784         account_name = principal;
 785
 786         maj_stat = gss_krb5_copy_service_keyblock(&min_stat,
 787                                                   gensec_gssapi_state->gssapi_context,
 788                                                   &keyblock);
 789
 790         maj_stat = gsskrb5_extract_authz_data_from_sec_context(&min_stat,
 791                                                                gensec_gssapi_state->gssapi_context,
 792                                                                KRB5_AUTHDATA_IF_RELEVANT,
 793                                                                &pac);
 794
 795         if (maj_stat == 0) {
 796                 DATA_BLOB pac_blob = data_blob_talloc(mem_ctx, pac.value, pac.length);
 797                 pac_blob = unwrap_pac(mem_ctx, &pac_blob);
 798                 gss_release_buffer(&min_stat, &pac);
 799
 800                 /* decode and verify the pac */
 801                 nt_status = kerberos_pac_logon_info(mem_ctx, &logon_info, pac_blob,
 802                                                     gensec_gssapi_state->smb_krb5_context->krb5_context,
 803                                                     NULL, keyblock);
 804
 805                 if (NT_STATUS_IS_OK(nt_status)) {
 806                         union netr_Validation validation;
 807                         validation.sam3 = &logon_info->info3;
 808                         nt_status = make_server_info_netlogon_validation(gensec_gssapi_state,
 809                                                                          account_name,
 810                                                                          3, &validation,
 811                                                                          &server_info);
 812                         if (!NT_STATUS_IS_OK(nt_status)) {
 813                                 talloc_free(mem_ctx);
 814                                 return nt_status;
 815                         }
 816                 } else {
 817                         maj_stat = 1;
 818                 }
 819         }
 820
 821         if (maj_stat) {
 822                 /* IF we have the PAC - otherwise we need to get this
 823                  * data from elsewere - local ldb, or (TODO) lookup of some
 824                  * kind...
 825                  *
 826                  * when heimdal can generate the PAC, we should fail if there's
 827                  * no PAC present
 828                  */
 829
 830                 DATA_BLOB user_sess_key = data_blob(NULL, 0);
 831                 DATA_BLOB lm_sess_key = data_blob(NULL, 0);
 832                 /* TODO: should we pass the krb5 session key in here? */
 833                 nt_status = sam_get_server_info(mem_ctx, account_name, realm,
 834                                                 user_sess_key, lm_sess_key,
 835                                                 &server_info);
 836                 if (!NT_STATUS_IS_OK(nt_status)) {
 837                         talloc_free(mem_ctx);
 838                         return nt_status;
 839                 }
 840         }
 841
 842         /* references the server_info into the session_info */
 843         nt_status = auth_generate_session_info(gensec_gssapi_state, server_info, &session_info);
 844         talloc_free(server_info);
 845         NT_STATUS_NOT_OK_RETURN(nt_status);
 846
 847         nt_status = gensec_gssapi_session_key(gensec_security, &session_info->session_key);
 848         NT_STATUS_NOT_OK_RETURN(nt_status);
 849
 850         *_session_info = session_info;
 851
 852         return NT_STATUS_OK;
 853 }
 854
 855 static const char *gensec_krb5_oids[] = {
 856         GENSEC_OID_KERBEROS5,
 857         GENSEC_OID_KERBEROS5_OLD,
 858         NULL
 859 };
 860
 861 /* As a server, this could in theory accept any GSSAPI mech */
 862 static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
 863         .name           = "gssapi_krb5",
 864         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 865         .oid            = gensec_krb5_oids,
 866         .client_start   = gensec_gssapi_client_start,
 867         .server_start   = gensec_gssapi_server_start,
 868         .magic          = gensec_gssapi_magic,
 869         .update         = gensec_gssapi_update,
 870         .session_key    = gensec_gssapi_session_key,
 871         .session_info   = gensec_gssapi_session_info,
 872         .sig_size       = gensec_gssapi_sig_size,
 873         .sign_packet    = gensec_gssapi_sign_packet,
 874         .check_packet   = gensec_gssapi_check_packet,
 875         .seal_packet    = gensec_gssapi_seal_packet,
 876         .unseal_packet  = gensec_gssapi_unseal_packet,
 877         .wrap           = gensec_gssapi_wrap,
 878         .unwrap         = gensec_gssapi_unwrap,
 879         .have_feature   = gensec_gssapi_have_feature,
 880         .enabled        = False
 881 };
 882
 883 NTSTATUS gensec_gssapi_init(void)
 884 {
 885         NTSTATUS ret;
 886
 887         ret = gensec_register(&gensec_gssapi_krb5_security_ops);
 888         if (!NT_STATUS_IS_OK(ret)) {
 889                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 890                         gensec_gssapi_krb5_security_ops.name));
 891                 return ret;
 892         }
 893
 894         return ret;
 895 }