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         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         if (maj_stat == GSS_S_COMPLETE) {
 392                 *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 393                 gss_release_buffer(&min_stat2, &output_token);
 394
 395                 return NT_STATUS_OK;
 396         } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 397                 *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 398                 gss_release_buffer(&min_stat2, &output_token);
 399
 400                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 401         } else {
 402                 if (maj_stat == GSS_S_FAILURE
 403                     && (min_stat == KRB5KRB_AP_ERR_BADVERSION || min_stat == KRB5KRB_AP_ERR_MSG_TYPE)) {
 404                         /* garbage input, possibly from the auto-mech detection */
 405                         return NT_STATUS_INVALID_PARAMETER;
 406                 }
 407                 DEBUG(1, ("GSS Update failed: %s\n",
 408                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 409                 return nt_status;
 410         }
 411 }
 412
 413 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 414                                    TALLOC_CTX *mem_ctx,
 415                                    const DATA_BLOB *in,
 416                                    DATA_BLOB *out)
 417 {
 418         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 419         OM_uint32 maj_stat, min_stat;
 420         gss_buffer_desc input_token, output_token;
 421         int conf_state;
 422         input_token.length = in->length;
 423         input_token.value = in->data;
 424
 425         maj_stat = gss_wrap(&min_stat,
 426                             gensec_gssapi_state->gssapi_context,
 427                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 428                             GSS_C_QOP_DEFAULT,
 429                             &input_token,
 430                             &conf_state,
 431                             &output_token);
 432         if (GSS_ERROR(maj_stat)) {
 433                 DEBUG(1, ("gensec_gssapi_wrap: GSS Wrap failed: %s\n",
 434                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 435                 return NT_STATUS_ACCESS_DENIED;
 436         }
 437
 438         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 439         gss_release_buffer(&min_stat, &output_token);
 440
 441         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 442             && !conf_state) {
 443                 return NT_STATUS_ACCESS_DENIED;
 444         }
 445         return NT_STATUS_OK;
 446 }
 447
 448 static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 449                                      TALLOC_CTX *mem_ctx,
 450                                      const DATA_BLOB *in,
 451                                      DATA_BLOB *out)
 452 {
 453         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 454         OM_uint32 maj_stat, min_stat;
 455         gss_buffer_desc input_token, output_token;
 456         int conf_state;
 457         gss_qop_t qop_state;
 458         input_token.length = in->length;
 459         input_token.value = in->data;
 460
 461         maj_stat = gss_unwrap(&min_stat,
 462                               gensec_gssapi_state->gssapi_context,
 463                               &input_token,
 464                               &output_token,
 465                               &conf_state,
 466                               &qop_state);
 467         if (GSS_ERROR(maj_stat)) {
 468                 DEBUG(1, ("gensec_gssapi_unwrap: GSS UnWrap failed: %s\n",
 469                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 470                 return NT_STATUS_ACCESS_DENIED;
 471         }
 472
 473         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 474         gss_release_buffer(&min_stat, &output_token);
 475
 476         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 477             && !conf_state) {
 478                 return NT_STATUS_ACCESS_DENIED;
 479         }
 480         return NT_STATUS_OK;
 481 }
 482
 483 static size_t gensec_gssapi_sig_size(struct gensec_security *gensec_security, size_t data_size)
 484 {
 485         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 486         OM_uint32 maj_stat, min_stat;
 487         OM_uint32 output_size;
 488         if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
 489             || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 490                        gensec_gssapi_state->gss_oid->length) != 0)) {
 491                 DEBUG(1, ("NO sig size available for this mech\n"));
 492                 return 0;
 493         }
 494
 495         maj_stat = gsskrb5_wrap_size(&min_stat,
 496                                      gensec_gssapi_state->gssapi_context,
 497                                      gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 498                                      GSS_C_QOP_DEFAULT,
 499                                      data_size,
 500                                      &output_size);
 501         if (GSS_ERROR(maj_stat)) {
 502                 TALLOC_CTX *mem_ctx = talloc_new(NULL);
 503                 DEBUG(1, ("gensec_gssapi_seal_packet: determinaing signature size with gss_wrap_size_limit failed: %s\n",
 504                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 505                 talloc_free(mem_ctx);
 506                 return 0;
 507         }
 508
 509         if (output_size < data_size) {
 510                 return 0;
 511         }
 512
 513         /* The difference between the max output and the max input must be the signature */
 514         return output_size - data_size;
 515 }
 516
 517 static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_security,
 518                                           TALLOC_CTX *mem_ctx,
 519                                           uint8_t *data, size_t length,
 520                                           const uint8_t *whole_pdu, size_t pdu_length,
 521                                           DATA_BLOB *sig)
 522 {
 523         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 524         OM_uint32 maj_stat, min_stat;
 525         gss_buffer_desc input_token, output_token;
 526         int conf_state;
 527         ssize_t sig_length;
 528
 529         input_token.length = length;
 530         input_token.value = data;
 531
 532         maj_stat = gss_wrap(&min_stat,
 533                             gensec_gssapi_state->gssapi_context,
 534                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 535                             GSS_C_QOP_DEFAULT,
 536                             &input_token,
 537                             &conf_state,
 538                             &output_token);
 539         if (GSS_ERROR(maj_stat)) {
 540                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap failed: %s\n",
 541                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 542                 return NT_STATUS_ACCESS_DENIED;
 543         }
 544
 545         sig_length = gensec_gssapi_sig_size(gensec_security, length);
 546
 547         /* Caller must pad to right boundary */
 548         if (output_token.length != (length + sig_length)) {
 549                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap length [%d] does not match caller length [%d] plus sig size [%d] = [%d]\n",
 550                           output_token.length, length, sig_length, length + sig_length));
 551                 return NT_STATUS_INTERNAL_ERROR;
 552         }
 553
 554         memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);
 555         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 556
 557         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 558         dump_data_pw("gensec_gssapi_seal_packet: clear\n", data, length);
 559         dump_data_pw("gensec_gssapi_seal_packet: sealed\n", ((uint8_t *)output_token.value) + sig_length, output_token.length - sig_length);
 560
 561         gss_release_buffer(&min_stat, &output_token);
 562
 563         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 564             && !conf_state) {
 565                 return NT_STATUS_ACCESS_DENIED;
 566         }
 567         return NT_STATUS_OK;
 568 }
 569
 570 static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_security,
 571                                             TALLOC_CTX *mem_ctx,
 572                                             uint8_t *data, size_t length,
 573                                             const uint8_t *whole_pdu, size_t pdu_length,
 574                                             const DATA_BLOB *sig)
 575 {
 576         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 577         OM_uint32 maj_stat, min_stat;
 578         gss_buffer_desc input_token, output_token;
 579         int conf_state;
 580         gss_qop_t qop_state;
 581         DATA_BLOB in;
 582
 583         dump_data_pw("gensec_gssapi_unseal_packet: sig\n", sig->data, sig->length);
 584
 585         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 586
 587         memcpy(in.data, sig->data, sig->length);
 588         memcpy(in.data + sig->length, data, length);
 589
 590         input_token.length = in.length;
 591         input_token.value = in.data;
 592
 593         maj_stat = gss_unwrap(&min_stat,
 594                               gensec_gssapi_state->gssapi_context,
 595                               &input_token,
 596                               &output_token,
 597                               &conf_state,
 598                               &qop_state);
 599         if (GSS_ERROR(maj_stat)) {
 600                 DEBUG(1, ("gensec_gssapi_unseal_packet: GSS UnWrap failed: %s\n",
 601                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 602                 return NT_STATUS_ACCESS_DENIED;
 603         }
 604
 605         if (output_token.length != length) {
 606                 return NT_STATUS_INTERNAL_ERROR;
 607         }
 608
 609         memcpy(data, output_token.value, length);
 610
 611         gss_release_buffer(&min_stat, &output_token);
 612
 613         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 614             && !conf_state) {
 615                 return NT_STATUS_ACCESS_DENIED;
 616         }
 617         return NT_STATUS_OK;
 618 }
 619
 620 static NTSTATUS gensec_gssapi_sign_packet(struct gensec_security *gensec_security,
 621                                           TALLOC_CTX *mem_ctx,
 622                                           const uint8_t *data, size_t length,
 623                                           const uint8_t *whole_pdu, size_t pdu_length,
 624                                           DATA_BLOB *sig)
 625 {
 626         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 627         OM_uint32 maj_stat, min_stat;
 628         gss_buffer_desc input_token, output_token;
 629         int conf_state;
 630         ssize_t sig_length = 0;
 631
 632         input_token.length = length;
 633         input_token.value = discard_const_p(uint8_t *, data);
 634
 635         maj_stat = gss_wrap(&min_stat,
 636                             gensec_gssapi_state->gssapi_context,
 637                             0,
 638                             GSS_C_QOP_DEFAULT,
 639                             &input_token,
 640                             &conf_state,
 641                             &output_token);
 642         if (GSS_ERROR(maj_stat)) {
 643                 DEBUG(1, ("GSS Wrap failed: %s\n",
 644                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 645                 return NT_STATUS_ACCESS_DENIED;
 646         }
 647
 648         if (output_token.length < length) {
 649                 return NT_STATUS_INTERNAL_ERROR;
 650         }
 651
 652         sig_length = gensec_gssapi_sig_size(gensec_security, length);
 653
 654         /* Caller must pad to right boundary */
 655         if (output_token.length != (length + sig_length)) {
 656                 DEBUG(1, ("gensec_gssapi_sign_packet: GSS Wrap length [%d] does not match caller length [%d] plus sig size [%d] = [%d]\n",
 657                           output_token.length, length, sig_length, length + sig_length));
 658                 return NT_STATUS_INTERNAL_ERROR;
 659         }
 660
 661         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 662
 663         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 664
 665         gss_release_buffer(&min_stat, &output_token);
 666
 667         return NT_STATUS_OK;
 668 }
 669
 670 static NTSTATUS gensec_gssapi_check_packet(struct gensec_security *gensec_security,
 671                                            TALLOC_CTX *mem_ctx,
 672                                            const uint8_t *data, size_t length,
 673                                            const uint8_t *whole_pdu, size_t pdu_length,
 674                                            const DATA_BLOB *sig)
 675 {
 676         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 677         OM_uint32 maj_stat, min_stat;
 678         gss_buffer_desc input_token, output_token;
 679         int conf_state;
 680         gss_qop_t qop_state;
 681         DATA_BLOB in;
 682
 683         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 684
 685         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 686
 687         memcpy(in.data, sig->data, sig->length);
 688         memcpy(in.data + sig->length, data, length);
 689
 690         input_token.length = in.length;
 691         input_token.value = in.data;
 692
 693         maj_stat = gss_unwrap(&min_stat,
 694                               gensec_gssapi_state->gssapi_context,
 695                               &input_token,
 696                               &output_token,
 697                               &conf_state,
 698                               &qop_state);
 699         if (GSS_ERROR(maj_stat)) {
 700                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 701                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 702                 return NT_STATUS_ACCESS_DENIED;
 703         }
 704
 705         if (output_token.length != length) {
 706                 return NT_STATUS_INTERNAL_ERROR;
 707         }
 708
 709         gss_release_buffer(&min_stat, &output_token);
 710
 711         return NT_STATUS_OK;
 712 }
 713
 714 static BOOL gensec_gssapi_have_feature(struct gensec_security *gensec_security,
 715                                        uint32_t feature)
 716 {
 717         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 718         if (feature & GENSEC_FEATURE_SIGN) {
 719                 return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
 720         }
 721         if (feature & GENSEC_FEATURE_SEAL) {
 722                 return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
 723         }
 724         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 725                 if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 726                     && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements, gensec_gssapi_state->gss_oid->length) == 0)) {
 727                         return True;
 728                 }
 729         }
 730         if (feature & GENSEC_FEATURE_DCE_STYLE) {
 731                 return gensec_gssapi_state->got_flags & GSS_C_DCE_STYLE;
 732         }
 733         if (feature & GENSEC_FEATURE_ASYNC_REPLIES) {
 734                 return True;
 735         }
 736         return False;
 737 }
 738
 739 static NTSTATUS gensec_gssapi_session_key(struct gensec_security *gensec_security,
 740                                           DATA_BLOB *session_key)
 741 {
 742         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 743
 744         if (gensec_gssapi_state->session_key.data) {
 745                 *session_key = gensec_gssapi_state->session_key;
 746                 return NT_STATUS_OK;
 747         }
 748
 749         /* Ensure we only call this for GSSAPI/krb5, otherwise things could get very ugly */
 750         if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 751             && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 752                        gensec_gssapi_state->gss_oid->length) == 0)) {
 753                 OM_uint32 maj_stat, min_stat;
 754                 gss_buffer_desc skey;
 755
 756                 maj_stat = gsskrb5_get_initiator_subkey(&min_stat,
 757                                                         gensec_gssapi_state->gssapi_context,
 758                                                         &skey);
 759
 760                 if (maj_stat == 0) {
 761                         DEBUG(10, ("Got KRB5 session key of length %d\n",
 762                                    (int)skey.length));
 763                         gensec_gssapi_state->session_key = data_blob_talloc(gensec_gssapi_state,
 764                                                                             skey.value, skey.length);
 765                         *session_key = gensec_gssapi_state->session_key;
 766                         dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 767
 768                         gss_release_buffer(&min_stat, &skey);
 769                         return NT_STATUS_OK;
 770                 }
 771                 return NT_STATUS_NO_USER_SESSION_KEY;
 772         }
 773
 774         DEBUG(1, ("NO session key for this mech\n"));
 775         return NT_STATUS_NO_USER_SESSION_KEY;
 776 }
 777
 778 static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_security,
 779                                          struct auth_session_info **_session_info)
 780 {
 781         NTSTATUS nt_status;
 782         TALLOC_CTX *mem_ctx;
 783         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 784         struct auth_serversupplied_info *server_info = NULL;
 785         struct auth_session_info *session_info = NULL;
 786         struct PAC_LOGON_INFO *logon_info;
 787         OM_uint32 maj_stat, min_stat;
 788         gss_buffer_desc name_token;
 789         gss_buffer_desc pac;
 790         krb5_keyblock *keyblock;
 791         time_t authtime;
 792         krb5_principal principal;
 793         char *principal_string;
 794
 795         if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
 796             || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 797                        gensec_gssapi_state->gss_oid->length) != 0)) {
 798                 DEBUG(1, ("NO session info available for this mech\n"));
 799                 return NT_STATUS_INVALID_PARAMETER;
 800         }
 801
 802         mem_ctx = talloc_named(gensec_gssapi_state, 0, "gensec_gssapi_session_info context");
 803         NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
 804
 805         maj_stat = gss_display_name (&min_stat,
 806                                      gensec_gssapi_state->client_name,
 807                                      &name_token,
 808                                      NULL);
 809         if (maj_stat) {
 810                 return NT_STATUS_FOOBAR;
 811         }
 812
 813         principal_string = talloc_strndup(mem_ctx, name_token.value, name_token.length);
 814
 815         gss_release_buffer(&min_stat, &name_token);
 816
 817         if (!principal_string) {
 818                 talloc_free(mem_ctx);
 819                 return NT_STATUS_NO_MEMORY;
 820         }
 821
 822         maj_stat = gss_krb5_copy_service_keyblock(&min_stat,
 823                                                   gensec_gssapi_state->gssapi_context,
 824                                                   &keyblock);
 825
 826         if (maj_stat == 0) {
 827                 maj_stat = gsskrb5_extract_authtime_from_sec_context(&min_stat,
 828                                                                      gensec_gssapi_state->gssapi_context,
 829                                                                      &authtime);
 830         }
 831
 832         if (maj_stat == 0) {
 833                 maj_stat = gsskrb5_extract_authz_data_from_sec_context(&min_stat,
 834                                                                        gensec_gssapi_state->gssapi_context,
 835                                                                        KRB5_AUTHDATA_IF_RELEVANT,
 836                                                                        &pac);
 837         }
 838
 839         if (maj_stat == 0) {
 840                 krb5_error_code ret;
 841                 DATA_BLOB pac_blob = data_blob_talloc(mem_ctx, pac.value, pac.length);
 842                 pac_blob = unwrap_pac(mem_ctx, &pac_blob);
 843                 gss_release_buffer(&min_stat, &pac);
 844
 845                 ret = krb5_parse_name(gensec_gssapi_state->smb_krb5_context->krb5_context,
 846                                       principal_string, &principal);
 847                 if (ret) {
 848                         talloc_free(mem_ctx);
 849                         return NT_STATUS_INVALID_PARAMETER;
 850                 }
 851
 852                 /* decode and verify the pac */
 853                 nt_status = kerberos_pac_logon_info(mem_ctx, &logon_info, pac_blob,
 854                                                     gensec_gssapi_state->smb_krb5_context->krb5_context,
 855                                                     NULL, keyblock, principal, authtime);
 856                 krb5_free_principal(gensec_gssapi_state->smb_krb5_context->krb5_context, principal);
 857
 858                 if (NT_STATUS_IS_OK(nt_status)) {
 859                         union netr_Validation validation;
 860                         validation.sam3 = &logon_info->info3;
 861                         nt_status = make_server_info_netlogon_validation(gensec_gssapi_state,
 862                                                                          NULL,
 863                                                                          3, &validation,
 864                                                                          &server_info);
 865                         if (!NT_STATUS_IS_OK(nt_status)) {
 866                                 talloc_free(mem_ctx);
 867                                 return nt_status;
 868                         }
 869                 } else {
 870                         maj_stat = 1;
 871                 }
 872         }
 873
 874         if (maj_stat) {
 875                 krb5_error_code ret;
 876                 DATA_BLOB user_sess_key = data_blob(NULL, 0);
 877                 DATA_BLOB lm_sess_key = data_blob(NULL, 0);
 878                 /* IF we have the PAC - otherwise we need to get this
 879                  * data from elsewere - local ldb, or (TODO) lookup of some
 880                  * kind...
 881                  *
 882                  * when heimdal can generate the PAC, we should fail if there's
 883                  * no PAC present
 884                  */
 885
 886                 char *account_name;
 887                 const char *realm;
 888                 ret = krb5_parse_name(gensec_gssapi_state->smb_krb5_context->krb5_context,
 889                                       principal_string, &principal);
 890                 if (ret) {
 891                         talloc_free(mem_ctx);
 892                         return NT_STATUS_INVALID_PARAMETER;
 893                 }
 894
 895                 realm = krb5_principal_get_realm(gensec_gssapi_state->smb_krb5_context->krb5_context,
 896                                                  principal);
 897                 ret = krb5_unparse_name_norealm(gensec_gssapi_state->smb_krb5_context->krb5_context,
 898                                                 principal, &account_name);
 899                 if (ret) {
 900                         krb5_free_principal(gensec_gssapi_state->smb_krb5_context->krb5_context, principal);
 901                         talloc_free(mem_ctx);
 902                         return NT_STATUS_NO_MEMORY;
 903                 }
 904
 905                 DEBUG(1, ("Unable to use PAC, resorting to local user lookup!\n"));
 906                 nt_status = sam_get_server_info(mem_ctx, account_name, realm,
 907                                                 user_sess_key, lm_sess_key,
 908                                                 &server_info);
 909                 free(account_name);
 910                 krb5_free_principal(gensec_gssapi_state->smb_krb5_context->krb5_context, principal);
 911
 912                 if (!NT_STATUS_IS_OK(nt_status)) {
 913                         talloc_free(mem_ctx);
 914                         return nt_status;
 915                 }
 916         }
 917
 918         /* references the server_info into the session_info */
 919         nt_status = auth_generate_session_info(gensec_gssapi_state, server_info, &session_info);
 920         talloc_free(mem_ctx);
 921         talloc_free(server_info);
 922         NT_STATUS_NOT_OK_RETURN(nt_status);
 923
 924         nt_status = gensec_gssapi_session_key(gensec_security, &session_info->session_key);
 925         NT_STATUS_NOT_OK_RETURN(nt_status);
 926
 927         *_session_info = session_info;
 928
 929         return NT_STATUS_OK;
 930 }
 931
 932 static const char *gensec_krb5_oids[] = {
 933         GENSEC_OID_KERBEROS5,
 934         GENSEC_OID_KERBEROS5_OLD,
 935         NULL
 936 };
 937
 938 /* As a server, this could in theory accept any GSSAPI mech */
 939 static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
 940         .name           = "gssapi_krb5",
 941         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 942         .oid            = gensec_krb5_oids,
 943         .client_start   = gensec_gssapi_client_start,
 944         .server_start   = gensec_gssapi_server_start,
 945         .magic          = gensec_gssapi_magic,
 946         .update         = gensec_gssapi_update,
 947         .session_key    = gensec_gssapi_session_key,
 948         .session_info   = gensec_gssapi_session_info,
 949         .sig_size       = gensec_gssapi_sig_size,
 950         .sign_packet    = gensec_gssapi_sign_packet,
 951         .check_packet   = gensec_gssapi_check_packet,
 952         .seal_packet    = gensec_gssapi_seal_packet,
 953         .unseal_packet  = gensec_gssapi_unseal_packet,
 954         .wrap           = gensec_gssapi_wrap,
 955         .unwrap         = gensec_gssapi_unwrap,
 956         .have_feature   = gensec_gssapi_have_feature,
 957         .enabled        = False
 958 };
 959
 960 NTSTATUS gensec_gssapi_init(void)
 961 {
 962         NTSTATUS ret;
 963
 964         ret = gensec_register(&gensec_gssapi_krb5_security_ops);
 965         if (!NT_STATUS_IS_OK(ret)) {
 966                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 967                         gensec_gssapi_krb5_security_ops.name));
 968                 return ret;
 969         }
 970
 971         return ret;
 972 }