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 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 = GSS_C_MUTUAL_FLAG;
 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         gss_OID name_type;
 233         OM_uint32 maj_stat, min_stat;
 234         const char *hostname = gensec_get_target_hostname(gensec_security);
 235         const char *principal;
 236
 237         if (!hostname) {
 238                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 239                 return NT_STATUS_INVALID_PARAMETER;
 240         }
 241         if (is_ipaddress(hostname)) {
 242                 DEBUG(2, ("Cannot do GSSAPI to a IP address"));
 243                 return NT_STATUS_INVALID_PARAMETER;
 244         }
 245
 246         nt_status = gensec_gssapi_start(gensec_security);
 247         if (!NT_STATUS_IS_OK(nt_status)) {
 248                 return nt_status;
 249         }
 250
 251         gensec_gssapi_state = gensec_security->private_data;
 252
 253         principal = gensec_get_target_principal(gensec_security);
 254         if (principal && lp_client_use_spnego_principal()) {
 255                 name_token.value = gensec_get_target_principal(gensec_security);
 256                 name_token.length = strlen(name_token.value);
 257                 name_type = GSS_C_NULL_OID;
 258         } else {
 259                 name_token.value = talloc_asprintf(gensec_gssapi_state, "%s@%s",
 260                                                    gensec_get_target_service(gensec_security),
 261                                                    hostname);
 262                 name_token.length = strlen(name_token.value);
 263                 name_type = GSS_C_NT_HOSTBASED_SERVICE;
 264         }
 265
 266         maj_stat = gss_import_name (&min_stat,
 267                                     &name_token,
 268                                     name_type,
 269                                     &gensec_gssapi_state->server_name);
 270         if (maj_stat) {
 271                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 272                           (char *)name_token.value,
 273                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 274                 return NT_STATUS_INVALID_PARAMETER;
 275         }
 276
 277         ret = cli_credentials_get_ccache(creds,
 278                                          &ccache);
 279         if (ret) {
 280                 DEBUG(1, ("Failed to get CCACHE for gensec_gssapi: %s\n", error_message(ret)));
 281                 return NT_STATUS_UNSUCCESSFUL;
 282         }
 283
 284         name_token.value = cli_credentials_get_principal(creds,
 285                                                          gensec_gssapi_state);
 286         name_token.length = strlen(name_token.value);
 287
 288         maj_stat = gss_import_name (&min_stat,
 289                                     &name_token,
 290                                     GSS_C_NT_USER_NAME,
 291                                     &gensec_gssapi_state->client_name);
 292         if (maj_stat) {
 293                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 294                           (char *)name_token.value,
 295                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 296                 return NT_STATUS_UNSUCCESSFUL;
 297         }
 298
 299         maj_stat = gsskrb5_acquire_cred(&min_stat,
 300                                         NULL, ccache->ccache,
 301                                         gensec_gssapi_state->client_name,
 302                                         GSS_C_INDEFINITE,
 303                                         GSS_C_NULL_OID_SET,
 304                                         GSS_C_INITIATE,
 305                                         &gensec_gssapi_state->cred,
 306                                         NULL,
 307                                         NULL);
 308         if (maj_stat) {
 309                 DEBUG(1, ("Aquiring initiator credentails failed: %s\n",
 310                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 311                 return NT_STATUS_UNSUCCESSFUL;
 312         }
 313
 314         return NT_STATUS_OK;
 315 }
 316
 317
 318 /**
 319  * Check if the packet is one for this mechansim
 320  *
 321  * @param gensec_security GENSEC state
 322  * @param in The request, as a DATA_BLOB
 323  * @return Error, INVALID_PARAMETER if it's not a packet for us
 324  *                or NT_STATUS_OK if the packet is ok.
 325  */
 326
 327 static NTSTATUS gensec_gssapi_magic(struct gensec_security *gensec_security,
 328                                     const DATA_BLOB *in)
 329 {
 330         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 331                 return NT_STATUS_OK;
 332         } else {
 333                 return NT_STATUS_INVALID_PARAMETER;
 334         }
 335 }
 336
 337
 338 /**
 339  * Next state function for the GSSAPI GENSEC mechanism
 340  *
 341  * @param gensec_gssapi_state GSSAPI State
 342  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 343  * @param in The request, as a DATA_BLOB
 344  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 345  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 346  *                or NT_STATUS_OK if the user is authenticated.
 347  */
 348
 349 static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 350                                    TALLOC_CTX *out_mem_ctx,
 351                                    const DATA_BLOB in, DATA_BLOB *out)
 352 {
 353         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 354         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 355         OM_uint32 maj_stat, min_stat;
 356         OM_uint32 min_stat2;
 357         gss_buffer_desc input_token, output_token;
 358         gss_OID gss_oid_p;
 359         input_token.length = in.length;
 360         input_token.value = in.data;
 361
 362         switch (gensec_security->gensec_role) {
 363         case GENSEC_CLIENT:
 364         {
 365                 maj_stat = gss_init_sec_context(&min_stat,
 366                                                 gensec_gssapi_state->cred,
 367                                                 &gensec_gssapi_state->gssapi_context,
 368                                                 gensec_gssapi_state->server_name,
 369                                                 discard_const_p(gss_OID_desc, gensec_gssapi_state->gss_oid),
 370                                                 gensec_gssapi_state->want_flags,
 371                                                 0,
 372                                                 gensec_gssapi_state->input_chan_bindings,
 373                                                 &input_token,
 374                                                 NULL,
 375                                                 &output_token,
 376                                                 &gensec_gssapi_state->got_flags, /* ret flags */
 377                                                 NULL);
 378                 break;
 379         }
 380         case GENSEC_SERVER:
 381         {
 382                 maj_stat = gss_accept_sec_context(&min_stat,
 383                                                   &gensec_gssapi_state->gssapi_context,
 384                                                   gensec_gssapi_state->cred,
 385                                                   &input_token,
 386                                                   gensec_gssapi_state->input_chan_bindings,
 387                                                   &gensec_gssapi_state->client_name,
 388                                                   &gss_oid_p,
 389                                                   &output_token,
 390                                                   &gensec_gssapi_state->got_flags,
 391                                                   NULL,
 392                                                   NULL);
 393                 gensec_gssapi_state->gss_oid = gss_oid_p;
 394                 break;
 395         }
 396         default:
 397                 return NT_STATUS_INVALID_PARAMETER;
 398
 399         }
 400
 401         if (maj_stat == GSS_S_COMPLETE) {
 402                 *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 403                 gss_release_buffer(&min_stat2, &output_token);
 404
 405                 return NT_STATUS_OK;
 406         } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 407                 *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 408                 gss_release_buffer(&min_stat2, &output_token);
 409
 410                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 411         } else {
 412                 if (maj_stat == GSS_S_FAILURE
 413                     && (min_stat == KRB5KRB_AP_ERR_BADVERSION || min_stat == KRB5KRB_AP_ERR_MSG_TYPE)) {
 414                         /* garbage input, possibly from the auto-mech detection */
 415                         return NT_STATUS_INVALID_PARAMETER;
 416                 }
 417                 DEBUG(1, ("GSS Update failed: %s\n",
 418                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 419                 return nt_status;
 420         }
 421 }
 422
 423 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 424                                    TALLOC_CTX *mem_ctx,
 425                                    const DATA_BLOB *in,
 426                                    DATA_BLOB *out)
 427 {
 428         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 429         OM_uint32 maj_stat, min_stat;
 430         gss_buffer_desc input_token, output_token;
 431         int conf_state;
 432         input_token.length = in->length;
 433         input_token.value = in->data;
 434
 435         maj_stat = gss_wrap(&min_stat,
 436                             gensec_gssapi_state->gssapi_context,
 437                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 438                             GSS_C_QOP_DEFAULT,
 439                             &input_token,
 440                             &conf_state,
 441                             &output_token);
 442         if (GSS_ERROR(maj_stat)) {
 443                 DEBUG(1, ("gensec_gssapi_wrap: GSS Wrap failed: %s\n",
 444                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 445                 return NT_STATUS_ACCESS_DENIED;
 446         }
 447
 448         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 449         gss_release_buffer(&min_stat, &output_token);
 450
 451         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 452             && !conf_state) {
 453                 return NT_STATUS_ACCESS_DENIED;
 454         }
 455         return NT_STATUS_OK;
 456 }
 457
 458 static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 459                                      TALLOC_CTX *mem_ctx,
 460                                      const DATA_BLOB *in,
 461                                      DATA_BLOB *out)
 462 {
 463         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 464         OM_uint32 maj_stat, min_stat;
 465         gss_buffer_desc input_token, output_token;
 466         int conf_state;
 467         gss_qop_t qop_state;
 468         input_token.length = in->length;
 469         input_token.value = in->data;
 470
 471         maj_stat = gss_unwrap(&min_stat,
 472                               gensec_gssapi_state->gssapi_context,
 473                               &input_token,
 474                               &output_token,
 475                               &conf_state,
 476                               &qop_state);
 477         if (GSS_ERROR(maj_stat)) {
 478                 DEBUG(1, ("gensec_gssapi_unwrap: GSS UnWrap failed: %s\n",
 479                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 480                 return NT_STATUS_ACCESS_DENIED;
 481         }
 482
 483         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 484         gss_release_buffer(&min_stat, &output_token);
 485
 486         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 487             && !conf_state) {
 488                 return NT_STATUS_ACCESS_DENIED;
 489         }
 490         return NT_STATUS_OK;
 491 }
 492
 493 static size_t gensec_gssapi_sig_size(struct gensec_security *gensec_security, size_t data_size)
 494 {
 495         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 496         OM_uint32 maj_stat, min_stat;
 497         OM_uint32 output_size;
 498         if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
 499             || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 500                        gensec_gssapi_state->gss_oid->length) != 0)) {
 501                 DEBUG(1, ("NO sig size available for this mech\n"));
 502                 return 0;
 503         }
 504
 505         maj_stat = gsskrb5_wrap_size(&min_stat,
 506                                      gensec_gssapi_state->gssapi_context,
 507                                      gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 508                                      GSS_C_QOP_DEFAULT,
 509                                      data_size,
 510                                      &output_size);
 511         if (GSS_ERROR(maj_stat)) {
 512                 TALLOC_CTX *mem_ctx = talloc_new(NULL);
 513                 DEBUG(1, ("gensec_gssapi_seal_packet: determinaing signature size with gss_wrap_size_limit failed: %s\n",
 514                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 515                 talloc_free(mem_ctx);
 516                 return 0;
 517         }
 518
 519         if (output_size < data_size) {
 520                 return 0;
 521         }
 522
 523         /* The difference between the max output and the max input must be the signature */
 524         return output_size - data_size;
 525 }
 526
 527 static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_security,
 528                                           TALLOC_CTX *mem_ctx,
 529                                           uint8_t *data, size_t length,
 530                                           const uint8_t *whole_pdu, size_t pdu_length,
 531                                           DATA_BLOB *sig)
 532 {
 533         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 534         OM_uint32 maj_stat, min_stat;
 535         gss_buffer_desc input_token, output_token;
 536         int conf_state;
 537         ssize_t sig_length;
 538
 539         input_token.length = length;
 540         input_token.value = data;
 541
 542         maj_stat = gss_wrap(&min_stat,
 543                             gensec_gssapi_state->gssapi_context,
 544                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 545                             GSS_C_QOP_DEFAULT,
 546                             &input_token,
 547                             &conf_state,
 548                             &output_token);
 549         if (GSS_ERROR(maj_stat)) {
 550                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap failed: %s\n",
 551                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 552                 return NT_STATUS_ACCESS_DENIED;
 553         }
 554
 555         sig_length = gensec_gssapi_sig_size(gensec_security, length);
 556
 557         /* Caller must pad to right boundary */
 558         if (output_token.length != (length + sig_length)) {
 559                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap length [%d] does not match caller length [%d] plus sig size [%d] = [%d]\n",
 560                           output_token.length, length, sig_length, length + sig_length));
 561                 return NT_STATUS_INTERNAL_ERROR;
 562         }
 563
 564         memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);
 565         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 566
 567         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 568         dump_data_pw("gensec_gssapi_seal_packet: clear\n", data, length);
 569         dump_data_pw("gensec_gssapi_seal_packet: sealed\n", ((uint8_t *)output_token.value) + sig_length, output_token.length - sig_length);
 570
 571         gss_release_buffer(&min_stat, &output_token);
 572
 573         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 574             && !conf_state) {
 575                 return NT_STATUS_ACCESS_DENIED;
 576         }
 577         return NT_STATUS_OK;
 578 }
 579
 580 static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_security,
 581                                             TALLOC_CTX *mem_ctx,
 582                                             uint8_t *data, size_t length,
 583                                             const uint8_t *whole_pdu, size_t pdu_length,
 584                                             const DATA_BLOB *sig)
 585 {
 586         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 587         OM_uint32 maj_stat, min_stat;
 588         gss_buffer_desc input_token, output_token;
 589         int conf_state;
 590         gss_qop_t qop_state;
 591         DATA_BLOB in;
 592
 593         dump_data_pw("gensec_gssapi_unseal_packet: sig\n", sig->data, sig->length);
 594
 595         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 596
 597         memcpy(in.data, sig->data, sig->length);
 598         memcpy(in.data + sig->length, data, length);
 599
 600         input_token.length = in.length;
 601         input_token.value = in.data;
 602
 603         maj_stat = gss_unwrap(&min_stat,
 604                               gensec_gssapi_state->gssapi_context,
 605                               &input_token,
 606                               &output_token,
 607                               &conf_state,
 608                               &qop_state);
 609         if (GSS_ERROR(maj_stat)) {
 610                 DEBUG(1, ("gensec_gssapi_unseal_packet: GSS UnWrap failed: %s\n",
 611                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 612                 return NT_STATUS_ACCESS_DENIED;
 613         }
 614
 615         if (output_token.length != length) {
 616                 return NT_STATUS_INTERNAL_ERROR;
 617         }
 618
 619         memcpy(data, output_token.value, length);
 620
 621         gss_release_buffer(&min_stat, &output_token);
 622
 623         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 624             && !conf_state) {
 625                 return NT_STATUS_ACCESS_DENIED;
 626         }
 627         return NT_STATUS_OK;
 628 }
 629
 630 static NTSTATUS gensec_gssapi_sign_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                                           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         ssize_t sig_length = 0;
 641
 642         input_token.length = length;
 643         input_token.value = discard_const_p(uint8_t *, data);
 644
 645         maj_stat = gss_wrap(&min_stat,
 646                             gensec_gssapi_state->gssapi_context,
 647                             0,
 648                             GSS_C_QOP_DEFAULT,
 649                             &input_token,
 650                             &conf_state,
 651                             &output_token);
 652         if (GSS_ERROR(maj_stat)) {
 653                 DEBUG(1, ("GSS Wrap failed: %s\n",
 654                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 655                 return NT_STATUS_ACCESS_DENIED;
 656         }
 657
 658         if (output_token.length < length) {
 659                 return NT_STATUS_INTERNAL_ERROR;
 660         }
 661
 662         sig_length = gensec_gssapi_sig_size(gensec_security, length);
 663
 664         /* Caller must pad to right boundary */
 665         if (output_token.length != (length + sig_length)) {
 666                 DEBUG(1, ("gensec_gssapi_sign_packet: GSS Wrap length [%d] does not match caller length [%d] plus sig size [%d] = [%d]\n",
 667                           output_token.length, length, sig_length, length + sig_length));
 668                 return NT_STATUS_INTERNAL_ERROR;
 669         }
 670
 671         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 672
 673         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 674
 675         gss_release_buffer(&min_stat, &output_token);
 676
 677         return NT_STATUS_OK;
 678 }
 679
 680 static NTSTATUS gensec_gssapi_check_packet(struct gensec_security *gensec_security,
 681                                            TALLOC_CTX *mem_ctx,
 682                                            const uint8_t *data, size_t length,
 683                                            const uint8_t *whole_pdu, size_t pdu_length,
 684                                            const DATA_BLOB *sig)
 685 {
 686         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 687         OM_uint32 maj_stat, min_stat;
 688         gss_buffer_desc input_token, output_token;
 689         int conf_state;
 690         gss_qop_t qop_state;
 691         DATA_BLOB in;
 692
 693         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 694
 695         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 696
 697         memcpy(in.data, sig->data, sig->length);
 698         memcpy(in.data + sig->length, data, length);
 699
 700         input_token.length = in.length;
 701         input_token.value = in.data;
 702
 703         maj_stat = gss_unwrap(&min_stat,
 704                               gensec_gssapi_state->gssapi_context,
 705                               &input_token,
 706                               &output_token,
 707                               &conf_state,
 708                               &qop_state);
 709         if (GSS_ERROR(maj_stat)) {
 710                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 711                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 712                 return NT_STATUS_ACCESS_DENIED;
 713         }
 714
 715         if (output_token.length != length) {
 716                 return NT_STATUS_INTERNAL_ERROR;
 717         }
 718
 719         gss_release_buffer(&min_stat, &output_token);
 720
 721         return NT_STATUS_OK;
 722 }
 723
 724 static BOOL gensec_gssapi_have_feature(struct gensec_security *gensec_security,
 725                                        uint32_t feature)
 726 {
 727         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 728         if (feature & GENSEC_FEATURE_SIGN) {
 729                 return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
 730         }
 731         if (feature & GENSEC_FEATURE_SEAL) {
 732                 return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
 733         }
 734         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 735                 if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 736                     && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements, gensec_gssapi_state->gss_oid->length) == 0)) {
 737                         return True;
 738                 }
 739         }
 740         if (feature & GENSEC_FEATURE_DCE_STYLE) {
 741                 return gensec_gssapi_state->got_flags & GSS_C_DCE_STYLE;
 742         }
 743         if (feature & GENSEC_FEATURE_ASYNC_REPLIES) {
 744                 return True;
 745         }
 746         return False;
 747 }
 748
 749 static NTSTATUS gensec_gssapi_session_key(struct gensec_security *gensec_security,
 750                                           DATA_BLOB *session_key)
 751 {
 752         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 753
 754         if (gensec_gssapi_state->session_key.data) {
 755                 *session_key = gensec_gssapi_state->session_key;
 756                 return NT_STATUS_OK;
 757         }
 758
 759         /* Ensure we only call this for GSSAPI/krb5, otherwise things could get very ugly */
 760         if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 761             && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 762                        gensec_gssapi_state->gss_oid->length) == 0)) {
 763                 OM_uint32 maj_stat, min_stat;
 764                 gss_buffer_desc skey;
 765
 766                 maj_stat = gsskrb5_get_initiator_subkey(&min_stat,
 767                                                         gensec_gssapi_state->gssapi_context,
 768                                                         &skey);
 769
 770                 if (maj_stat == 0) {
 771                         DEBUG(10, ("Got KRB5 session key of length %d\n",
 772                                    (int)skey.length));
 773                         gensec_gssapi_state->session_key = data_blob_talloc(gensec_gssapi_state,
 774                                                                             skey.value, skey.length);
 775                         *session_key = gensec_gssapi_state->session_key;
 776                         dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 777
 778                         gss_release_buffer(&min_stat, &skey);
 779                         return NT_STATUS_OK;
 780                 }
 781                 return NT_STATUS_NO_USER_SESSION_KEY;
 782         }
 783
 784         DEBUG(1, ("NO session key for this mech\n"));
 785         return NT_STATUS_NO_USER_SESSION_KEY;
 786 }
 787
 788 static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_security,
 789                                          struct auth_session_info **_session_info)
 790 {
 791         NTSTATUS nt_status;
 792         TALLOC_CTX *mem_ctx;
 793         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 794         struct auth_serversupplied_info *server_info = NULL;
 795         struct auth_session_info *session_info = NULL;
 796         struct PAC_LOGON_INFO *logon_info;
 797         OM_uint32 maj_stat, min_stat;
 798         gss_buffer_desc name_token;
 799         gss_buffer_desc pac;
 800         krb5_keyblock *keyblock;
 801         time_t authtime;
 802         krb5_principal principal;
 803         char *principal_string;
 804
 805         if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
 806             || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 807                        gensec_gssapi_state->gss_oid->length) != 0)) {
 808                 DEBUG(1, ("NO session info available for this mech\n"));
 809                 return NT_STATUS_INVALID_PARAMETER;
 810         }
 811
 812         mem_ctx = talloc_named(gensec_gssapi_state, 0, "gensec_gssapi_session_info context");
 813         NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
 814
 815         maj_stat = gss_display_name (&min_stat,
 816                                      gensec_gssapi_state->client_name,
 817                                      &name_token,
 818                                      NULL);
 819         if (maj_stat) {
 820                 return NT_STATUS_FOOBAR;
 821         }
 822
 823         principal_string = talloc_strndup(mem_ctx, name_token.value, name_token.length);
 824
 825         gss_release_buffer(&min_stat, &name_token);
 826
 827         if (!principal_string) {
 828                 talloc_free(mem_ctx);
 829                 return NT_STATUS_NO_MEMORY;
 830         }
 831
 832         maj_stat = gss_krb5_copy_service_keyblock(&min_stat,
 833                                                   gensec_gssapi_state->gssapi_context,
 834                                                   &keyblock);
 835
 836         if (maj_stat == 0) {
 837                 maj_stat = gsskrb5_extract_authtime_from_sec_context(&min_stat,
 838                                                                      gensec_gssapi_state->gssapi_context,
 839                                                                      &authtime);
 840         }
 841
 842         if (maj_stat == 0) {
 843                 maj_stat = gsskrb5_extract_authz_data_from_sec_context(&min_stat,
 844                                                                        gensec_gssapi_state->gssapi_context,
 845                                                                        KRB5_AUTHDATA_IF_RELEVANT,
 846                                                                        &pac);
 847         }
 848
 849         if (maj_stat == 0) {
 850                 krb5_error_code ret;
 851                 DATA_BLOB pac_blob = data_blob_talloc(mem_ctx, pac.value, pac.length);
 852                 pac_blob = unwrap_pac(mem_ctx, &pac_blob);
 853                 gss_release_buffer(&min_stat, &pac);
 854
 855                 ret = krb5_parse_name(gensec_gssapi_state->smb_krb5_context->krb5_context,
 856                                       principal_string, &principal);
 857                 if (ret) {
 858                         talloc_free(mem_ctx);
 859                         return NT_STATUS_INVALID_PARAMETER;
 860                 }
 861
 862                 /* decode and verify the pac */
 863                 nt_status = kerberos_pac_logon_info(mem_ctx, &logon_info, pac_blob,
 864                                                     gensec_gssapi_state->smb_krb5_context->krb5_context,
 865                                                     NULL, keyblock, principal, authtime);
 866                 krb5_free_principal(gensec_gssapi_state->smb_krb5_context->krb5_context, principal);
 867
 868                 if (NT_STATUS_IS_OK(nt_status)) {
 869                         union netr_Validation validation;
 870                         validation.sam3 = &logon_info->info3;
 871                         nt_status = make_server_info_netlogon_validation(gensec_gssapi_state,
 872                                                                          NULL,
 873                                                                          3, &validation,
 874                                                                          &server_info);
 875                         if (!NT_STATUS_IS_OK(nt_status)) {
 876                                 talloc_free(mem_ctx);
 877                                 return nt_status;
 878                         }
 879                 } else {
 880                         maj_stat = 1;
 881                 }
 882         }
 883
 884         if (maj_stat) {
 885                 krb5_error_code ret;
 886                 DATA_BLOB user_sess_key = data_blob(NULL, 0);
 887                 DATA_BLOB lm_sess_key = data_blob(NULL, 0);
 888                 /* IF we have the PAC - otherwise we need to get this
 889                  * data from elsewere - local ldb, or (TODO) lookup of some
 890                  * kind...
 891                  *
 892                  * when heimdal can generate the PAC, we should fail if there's
 893                  * no PAC present
 894                  */
 895
 896                 char *account_name;
 897                 const char *realm;
 898                 ret = krb5_parse_name(gensec_gssapi_state->smb_krb5_context->krb5_context,
 899                                       principal_string, &principal);
 900                 if (ret) {
 901                         talloc_free(mem_ctx);
 902                         return NT_STATUS_INVALID_PARAMETER;
 903                 }
 904
 905                 realm = krb5_principal_get_realm(gensec_gssapi_state->smb_krb5_context->krb5_context,
 906                                                  principal);
 907                 ret = krb5_unparse_name_norealm(gensec_gssapi_state->smb_krb5_context->krb5_context,
 908                                                 principal, &account_name);
 909                 if (ret) {
 910                         krb5_free_principal(gensec_gssapi_state->smb_krb5_context->krb5_context, principal);
 911                         talloc_free(mem_ctx);
 912                         return NT_STATUS_NO_MEMORY;
 913                 }
 914
 915                 DEBUG(1, ("Unable to use PAC, resorting to local user lookup!\n"));
 916                 nt_status = sam_get_server_info(mem_ctx, account_name, realm,
 917                                                 user_sess_key, lm_sess_key,
 918                                                 &server_info);
 919                 free(account_name);
 920                 krb5_free_principal(gensec_gssapi_state->smb_krb5_context->krb5_context, principal);
 921
 922                 if (!NT_STATUS_IS_OK(nt_status)) {
 923                         talloc_free(mem_ctx);
 924                         return nt_status;
 925                 }
 926         }
 927
 928         /* references the server_info into the session_info */
 929         nt_status = auth_generate_session_info(gensec_gssapi_state, server_info, &session_info);
 930         talloc_free(mem_ctx);
 931         talloc_free(server_info);
 932         NT_STATUS_NOT_OK_RETURN(nt_status);
 933
 934         nt_status = gensec_gssapi_session_key(gensec_security, &session_info->session_key);
 935         NT_STATUS_NOT_OK_RETURN(nt_status);
 936
 937         *_session_info = session_info;
 938
 939         return NT_STATUS_OK;
 940 }
 941
 942 static const char *gensec_krb5_oids[] = {
 943         GENSEC_OID_KERBEROS5,
 944         GENSEC_OID_KERBEROS5_OLD,
 945         NULL
 946 };
 947
 948 /* As a server, this could in theory accept any GSSAPI mech */
 949 static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
 950         .name           = "gssapi_krb5",
 951         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 952         .oid            = gensec_krb5_oids,
 953         .client_start   = gensec_gssapi_client_start,
 954         .server_start   = gensec_gssapi_server_start,
 955         .magic          = gensec_gssapi_magic,
 956         .update         = gensec_gssapi_update,
 957         .session_key    = gensec_gssapi_session_key,
 958         .session_info   = gensec_gssapi_session_info,
 959         .sig_size       = gensec_gssapi_sig_size,
 960         .sign_packet    = gensec_gssapi_sign_packet,
 961         .check_packet   = gensec_gssapi_check_packet,
 962         .seal_packet    = gensec_gssapi_seal_packet,
 963         .unseal_packet  = gensec_gssapi_unseal_packet,
 964         .wrap           = gensec_gssapi_wrap,
 965         .unwrap         = gensec_gssapi_unwrap,
 966         .have_feature   = gensec_gssapi_have_feature,
 967         .enabled        = False
 968 };
 969
 970 NTSTATUS gensec_gssapi_init(void)
 971 {
 972         NTSTATUS ret;
 973
 974         ret = gensec_register(&gensec_gssapi_krb5_security_ops);
 975         if (!NT_STATUS_IS_OK(ret)) {
 976                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 977                         gensec_gssapi_krb5_security_ops.name));
 978                 return ret;
 979         }
 980
 981         return ret;
 982 }