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 = 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         struct gensec_gssapi_state *gensec_gssapi_state;
 158         struct cli_credentials *machine_account;
 159
 160         nt_status = gensec_gssapi_start(gensec_security);
 161         if (!NT_STATUS_IS_OK(nt_status)) {
 162                 return nt_status;
 163         }
 164
 165         gensec_gssapi_state = gensec_security->private_data;
 166
 167         machine_account = cli_credentials_init(gensec_gssapi_state);
 168         cli_credentials_set_conf(machine_account);
 169         nt_status = cli_credentials_set_machine_account(machine_account);
 170
 171         if (!NT_STATUS_IS_OK(nt_status)) {
 172                 DEBUG(3, ("Could not obtain machine account credentials from the local database\n"));
 173                 talloc_free(machine_account);
 174                 return nt_status;
 175         } else {
 176                 nt_status = create_memory_keytab(gensec_gssapi_state,
 177                                                  machine_account,
 178                                                  gensec_gssapi_state->smb_krb5_context,
 179                                                  &gensec_gssapi_state->keytab);
 180                 talloc_free(machine_account);
 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         maj_stat = gsskrb5_acquire_cred(&min_stat,
 189                                         gensec_gssapi_state->keytab, NULL,
 190                                         NULL,
 191                                         GSS_C_INDEFINITE,
 192                                         GSS_C_NULL_OID_SET,
 193                                         GSS_C_ACCEPT,
 194                                         &gensec_gssapi_state->cred,
 195                                         NULL,
 196                                         NULL);
 197         if (maj_stat) {
 198                 DEBUG(1, ("Aquiring acceptor credentails failed: %s\n",
 199                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 200                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 201         }
 202
 203         return NT_STATUS_OK;
 204
 205 }
 206
 207 static NTSTATUS gensec_gssapi_client_start(struct gensec_security *gensec_security)
 208 {
 209         struct gensec_gssapi_state *gensec_gssapi_state;
 210         struct cli_credentials *creds = gensec_get_credentials(gensec_security);
 211         struct ccache_container *ccache;
 212         krb5_error_code ret;
 213         NTSTATUS nt_status;
 214         gss_buffer_desc name_token;
 215         OM_uint32 maj_stat, min_stat;
 216         const char *hostname = gensec_get_target_hostname(gensec_security);
 217
 218         if (!hostname) {
 219                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 220                 return NT_STATUS_INVALID_PARAMETER;
 221         }
 222         if (is_ipaddress(hostname)) {
 223                 DEBUG(2, ("Cannot do GSSAPI to a IP address"));
 224                 return NT_STATUS_INVALID_PARAMETER;
 225         }
 226
 227         nt_status = gensec_gssapi_start(gensec_security);
 228         if (!NT_STATUS_IS_OK(nt_status)) {
 229                 return nt_status;
 230         }
 231
 232         gensec_gssapi_state = gensec_security->private_data;
 233
 234         name_token.value = talloc_asprintf(gensec_gssapi_state, "%s@%s",
 235                                            gensec_get_target_service(gensec_security),
 236                                            hostname);
 237         name_token.length = strlen(name_token.value);
 238
 239         maj_stat = gss_import_name (&min_stat,
 240                                     &name_token,
 241                                     GSS_C_NT_HOSTBASED_SERVICE,
 242                                     &gensec_gssapi_state->server_name);
 243         if (maj_stat) {
 244                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 245                           (char *)name_token.value,
 246                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 247                 return NT_STATUS_INVALID_PARAMETER;
 248         }
 249
 250         ret = cli_credentials_get_ccache(creds,
 251                                          &ccache);
 252         if (ret) {
 253                 DEBUG(1, ("Failed to get CCACHE for gensec_gssapi: %s\n", error_message(ret)));
 254                 return NT_STATUS_UNSUCCESSFUL;
 255         }
 256
 257         name_token.value = cli_credentials_get_principal(creds,
 258                                                          gensec_gssapi_state);
 259         name_token.length = strlen(name_token.value);
 260
 261         maj_stat = gss_import_name (&min_stat,
 262                                     &name_token,
 263                                     GSS_C_NT_USER_NAME,
 264                                     &gensec_gssapi_state->client_name);
 265         if (maj_stat) {
 266                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 267                           (char *)name_token.value,
 268                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 269                 return NT_STATUS_UNSUCCESSFUL;
 270         }
 271
 272         maj_stat = gsskrb5_acquire_cred(&min_stat,
 273                                         NULL, ccache->ccache,
 274                                         gensec_gssapi_state->client_name,
 275                                         GSS_C_INDEFINITE,
 276                                         GSS_C_NULL_OID_SET,
 277                                         GSS_C_INITIATE,
 278                                         &gensec_gssapi_state->cred,
 279                                         NULL,
 280                                         NULL);
 281         if (maj_stat) {
 282                 DEBUG(1, ("Aquiring initiator credentails failed: %s\n",
 283                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 284                 return NT_STATUS_UNSUCCESSFUL;
 285         }
 286
 287         return NT_STATUS_OK;
 288 }
 289
 290
 291 /**
 292  * Check if the packet is one for this mechansim
 293  *
 294  * @param gensec_security GENSEC state
 295  * @param in The request, as a DATA_BLOB
 296  * @return Error, INVALID_PARAMETER if it's not a packet for us
 297  *                or NT_STATUS_OK if the packet is ok.
 298  */
 299
 300 static NTSTATUS gensec_gssapi_magic(struct gensec_security *gensec_security,
 301                                     const DATA_BLOB *in)
 302 {
 303         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 304                 return NT_STATUS_OK;
 305         } else {
 306                 return NT_STATUS_INVALID_PARAMETER;
 307         }
 308 }
 309
 310
 311 /**
 312  * Next state function for the GSSAPI GENSEC mechanism
 313  *
 314  * @param gensec_gssapi_state GSSAPI State
 315  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 316  * @param in The request, as a DATA_BLOB
 317  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 318  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 319  *                or NT_STATUS_OK if the user is authenticated.
 320  */
 321
 322 static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 323                                    TALLOC_CTX *out_mem_ctx,
 324                                    const DATA_BLOB in, DATA_BLOB *out)
 325 {
 326         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 327         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 328         OM_uint32 maj_stat, min_stat;
 329         OM_uint32 min_stat2;
 330         gss_buffer_desc input_token, output_token;
 331         gss_OID gss_oid_p;
 332         input_token.length = in.length;
 333         input_token.value = in.data;
 334
 335         switch (gensec_security->gensec_role) {
 336         case GENSEC_CLIENT:
 337         {
 338                 maj_stat = gss_init_sec_context(&min_stat,
 339                                                 gensec_gssapi_state->cred,
 340                                                 &gensec_gssapi_state->gssapi_context,
 341                                                 gensec_gssapi_state->server_name,
 342                                                 discard_const_p(gss_OID_desc, gensec_gssapi_state->gss_oid),
 343                                                 gensec_gssapi_state->want_flags,
 344                                                 0,
 345                                                 gensec_gssapi_state->input_chan_bindings,
 346                                                 &input_token,
 347                                                 NULL,
 348                                                 &output_token,
 349                                                 &gensec_gssapi_state->got_flags, /* ret flags */
 350                                                 NULL);
 351                 break;
 352         }
 353         case GENSEC_SERVER:
 354         {
 355                 maj_stat = gss_accept_sec_context(&min_stat,
 356                                                   &gensec_gssapi_state->gssapi_context,
 357                                                   gensec_gssapi_state->cred,
 358                                                   &input_token,
 359                                                   gensec_gssapi_state->input_chan_bindings,
 360                                                   &gensec_gssapi_state->client_name,
 361                                                   &gss_oid_p,
 362                                                   &output_token,
 363                                                   &gensec_gssapi_state->got_flags,
 364                                                   NULL,
 365                                                   NULL);
 366                 gensec_gssapi_state->gss_oid = gss_oid_p;
 367                 break;
 368         }
 369         default:
 370                 return NT_STATUS_INVALID_PARAMETER;
 371
 372         }
 373
 374         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 375         gss_release_buffer(&min_stat2, &output_token);
 376
 377         if (maj_stat == GSS_S_COMPLETE) {
 378                 return NT_STATUS_OK;
 379         } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 380                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 381         } else {
 382                 if (maj_stat == GSS_S_FAILURE
 383                     && (min_stat == KRB5KRB_AP_ERR_BADVERSION || min_stat == KRB5KRB_AP_ERR_MSG_TYPE)) {
 384                         /* garbage input, possibly from the auto-mech detection */
 385                         return NT_STATUS_INVALID_PARAMETER;
 386                 }
 387                 DEBUG(1, ("GSS Update failed: %s\n",
 388                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 389                 return nt_status;
 390         }
 391 }
 392
 393 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 394                                    TALLOC_CTX *mem_ctx,
 395                                    const DATA_BLOB *in,
 396                                    DATA_BLOB *out)
 397 {
 398         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 399         OM_uint32 maj_stat, min_stat;
 400         gss_buffer_desc input_token, output_token;
 401         int conf_state;
 402         input_token.length = in->length;
 403         input_token.value = in->data;
 404
 405         maj_stat = gss_wrap(&min_stat,
 406                             gensec_gssapi_state->gssapi_context,
 407                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 408                             GSS_C_QOP_DEFAULT,
 409                             &input_token,
 410                             &conf_state,
 411                             &output_token);
 412         if (GSS_ERROR(maj_stat)) {
 413                 DEBUG(1, ("GSS Wrap failed: %s\n",
 414                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 415                 return NT_STATUS_ACCESS_DENIED;
 416         }
 417         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 418
 419         gss_release_buffer(&min_stat, &output_token);
 420
 421         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 422             && !conf_state) {
 423                 return NT_STATUS_ACCESS_DENIED;
 424         }
 425         return NT_STATUS_OK;
 426 }
 427
 428 static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 429                                      TALLOC_CTX *mem_ctx,
 430                                      const DATA_BLOB *in,
 431                                      DATA_BLOB *out)
 432 {
 433         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 434         OM_uint32 maj_stat, min_stat;
 435         gss_buffer_desc input_token, output_token;
 436         int conf_state;
 437         gss_qop_t qop_state;
 438         input_token.length = in->length;
 439         input_token.value = in->data;
 440
 441         maj_stat = gss_unwrap(&min_stat,
 442                               gensec_gssapi_state->gssapi_context,
 443                               &input_token,
 444                               &output_token,
 445                               &conf_state,
 446                               &qop_state);
 447         if (GSS_ERROR(maj_stat)) {
 448                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 449                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 450                 return NT_STATUS_ACCESS_DENIED;
 451         }
 452         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 453
 454         gss_release_buffer(&min_stat, &output_token);
 455
 456         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 457             && !conf_state) {
 458                 return NT_STATUS_ACCESS_DENIED;
 459         }
 460         return NT_STATUS_OK;
 461 }
 462
 463 static size_t gensec_gssapi_sig_size(struct gensec_security *gensec_security)
 464 {
 465         /* not const but work for DCERPC packets and arcfour */
 466         return 45;
 467 }
 468
 469 static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_security,
 470                                           TALLOC_CTX *mem_ctx,
 471                                           uint8_t *data, size_t length,
 472                                           const uint8_t *whole_pdu, size_t pdu_length,
 473                                           DATA_BLOB *sig)
 474 {
 475         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 476         OM_uint32 maj_stat, min_stat;
 477         gss_buffer_desc input_token, output_token;
 478         int conf_state;
 479         ssize_t sig_length = 0;
 480
 481         input_token.length = length;
 482         input_token.value = data;
 483
 484         maj_stat = gss_wrap(&min_stat,
 485                             gensec_gssapi_state->gssapi_context,
 486                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 487                             GSS_C_QOP_DEFAULT,
 488                             &input_token,
 489                             &conf_state,
 490                             &output_token);
 491         if (GSS_ERROR(maj_stat)) {
 492                 DEBUG(1, ("GSS Wrap failed: %s\n",
 493                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 494                 return NT_STATUS_ACCESS_DENIED;
 495         }
 496
 497         if (output_token.length < length) {
 498                 return NT_STATUS_INTERNAL_ERROR;
 499         }
 500
 501         sig_length = 45;
 502
 503         memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);
 504         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 505
 506         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 507         dump_data_pw("gensec_gssapi_seal_packet: clear\n", data, length);
 508         dump_data_pw("gensec_gssapi_seal_packet: sealed\n", ((uint8_t *)output_token.value) + sig_length, output_token.length - sig_length);
 509
 510         gss_release_buffer(&min_stat, &output_token);
 511
 512         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 513             && !conf_state) {
 514                 return NT_STATUS_ACCESS_DENIED;
 515         }
 516         return NT_STATUS_OK;
 517 }
 518
 519 static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_security,
 520                                             TALLOC_CTX *mem_ctx,
 521                                             uint8_t *data, size_t length,
 522                                             const uint8_t *whole_pdu, size_t pdu_length,
 523                                             const DATA_BLOB *sig)
 524 {
 525         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 526         OM_uint32 maj_stat, min_stat;
 527         gss_buffer_desc input_token, output_token;
 528         int conf_state;
 529         gss_qop_t qop_state;
 530         DATA_BLOB in;
 531
 532         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 533
 534         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 535
 536         memcpy(in.data, sig->data, sig->length);
 537         memcpy(in.data + sig->length, data, length);
 538
 539         input_token.length = in.length;
 540         input_token.value = in.data;
 541
 542         maj_stat = gss_unwrap(&min_stat,
 543                               gensec_gssapi_state->gssapi_context,
 544                               &input_token,
 545                               &output_token,
 546                               &conf_state,
 547                               &qop_state);
 548         if (GSS_ERROR(maj_stat)) {
 549                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 550                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 551                 return NT_STATUS_ACCESS_DENIED;
 552         }
 553
 554         if (output_token.length != length) {
 555                 return NT_STATUS_INTERNAL_ERROR;
 556         }
 557
 558         memcpy(data, output_token.value, length);
 559
 560         gss_release_buffer(&min_stat, &output_token);
 561
 562         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 563             && !conf_state) {
 564                 return NT_STATUS_ACCESS_DENIED;
 565         }
 566         return NT_STATUS_OK;
 567 }
 568
 569 static NTSTATUS gensec_gssapi_sign_packet(struct gensec_security *gensec_security,
 570                                           TALLOC_CTX *mem_ctx,
 571                                           const uint8_t *data, size_t length,
 572                                           const uint8_t *whole_pdu, size_t pdu_length,
 573                                           DATA_BLOB *sig)
 574 {
 575         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 576         OM_uint32 maj_stat, min_stat;
 577         gss_buffer_desc input_token, output_token;
 578         int conf_state;
 579         ssize_t sig_length = 0;
 580
 581         input_token.length = length;
 582         input_token.value = discard_const_p(uint8_t *, data);
 583
 584         maj_stat = gss_wrap(&min_stat,
 585                             gensec_gssapi_state->gssapi_context,
 586                             0,
 587                             GSS_C_QOP_DEFAULT,
 588                             &input_token,
 589                             &conf_state,
 590                             &output_token);
 591         if (GSS_ERROR(maj_stat)) {
 592                 DEBUG(1, ("GSS Wrap failed: %s\n",
 593                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 594                 return NT_STATUS_ACCESS_DENIED;
 595         }
 596
 597         if (output_token.length < length) {
 598                 return NT_STATUS_INTERNAL_ERROR;
 599         }
 600
 601         sig_length = 45;
 602
 603         /*memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);*/
 604         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 605
 606         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 607
 608         gss_release_buffer(&min_stat, &output_token);
 609
 610         return NT_STATUS_OK;
 611 }
 612
 613 static NTSTATUS gensec_gssapi_check_packet(struct gensec_security *gensec_security,
 614                                            TALLOC_CTX *mem_ctx,
 615                                            const uint8_t *data, size_t length,
 616                                            const uint8_t *whole_pdu, size_t pdu_length,
 617                                            const DATA_BLOB *sig)
 618 {
 619         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 620         OM_uint32 maj_stat, min_stat;
 621         gss_buffer_desc input_token, output_token;
 622         int conf_state;
 623         gss_qop_t qop_state;
 624         DATA_BLOB in;
 625
 626         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 627
 628         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 629
 630         memcpy(in.data, sig->data, sig->length);
 631         memcpy(in.data + sig->length, data, length);
 632
 633         input_token.length = in.length;
 634         input_token.value = in.data;
 635
 636         maj_stat = gss_unwrap(&min_stat,
 637                               gensec_gssapi_state->gssapi_context,
 638                               &input_token,
 639                               &output_token,
 640                               &conf_state,
 641                               &qop_state);
 642         if (GSS_ERROR(maj_stat)) {
 643                 DEBUG(1, ("GSS UnWrap 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         gss_release_buffer(&min_stat, &output_token);
 653
 654         return NT_STATUS_OK;
 655 }
 656
 657 static BOOL gensec_gssapi_have_feature(struct gensec_security *gensec_security,
 658                                        uint32_t feature)
 659 {
 660         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 661         if (feature & GENSEC_FEATURE_SIGN) {
 662                 return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
 663         }
 664         if (feature & GENSEC_FEATURE_SEAL) {
 665                 return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
 666         }
 667         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 668                 if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 669                     && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements, gensec_gssapi_state->gss_oid->length) == 0)) {
 670                         return True;
 671                 }
 672         }
 673         if (feature & GENSEC_FEATURE_DCE_STYLE) {
 674                 return True;
 675         }
 676         if (feature & GENSEC_FEATURE_ASYNC_REPLIES) {
 677                 return True;
 678         }
 679         return False;
 680 }
 681
 682 static NTSTATUS gensec_gssapi_session_key(struct gensec_security *gensec_security,
 683                                           DATA_BLOB *session_key)
 684 {
 685         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 686
 687         if (gensec_gssapi_state->session_key.data) {
 688                 *session_key = gensec_gssapi_state->session_key;
 689                 return NT_STATUS_OK;
 690         }
 691
 692         /* Ensure we only call this for GSSAPI/krb5, otherwise things could get very ugly */
 693         if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 694             && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 695                        gensec_gssapi_state->gss_oid->length) == 0)) {
 696                 OM_uint32 maj_stat, min_stat;
 697                 gss_buffer_desc skey;
 698
 699                 maj_stat = gsskrb5_get_initiator_subkey(&min_stat,
 700                                                         gensec_gssapi_state->gssapi_context,
 701                                                         &skey);
 702
 703                 if (maj_stat == 0) {
 704                         DEBUG(10, ("Got KRB5 session key of length %d\n",
 705                                    (int)skey.length));
 706                         gensec_gssapi_state->session_key = data_blob_talloc(gensec_gssapi_state,
 707                                                                             skey.value, skey.length);
 708                         *session_key = gensec_gssapi_state->session_key;
 709                         dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 710
 711                         gss_release_buffer(&min_stat, &skey);
 712                         return NT_STATUS_OK;
 713                 }
 714                 return NT_STATUS_NO_USER_SESSION_KEY;
 715         }
 716
 717         DEBUG(1, ("NO session key for this mech\n"));
 718         return NT_STATUS_NO_USER_SESSION_KEY;
 719 }
 720
 721 static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_security,
 722                                          struct auth_session_info **_session_info)
 723 {
 724         NTSTATUS nt_status;
 725         TALLOC_CTX *mem_ctx;
 726         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 727         struct auth_serversupplied_info *server_info = NULL;
 728         struct auth_session_info *session_info = NULL;
 729         struct PAC_LOGON_INFO *logon_info;
 730         char *p;
 731         char *principal;
 732         const char *account_name;
 733         const char *realm;
 734         OM_uint32 maj_stat, min_stat;
 735         gss_buffer_desc name_token;
 736         gss_buffer_desc pac;
 737         krb5_keyblock *keyblock;
 738
 739         mem_ctx = talloc_named(gensec_gssapi_state, 0, "gensec_gssapi_session_info context");
 740         NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
 741
 742         maj_stat = gss_display_name (&min_stat,
 743                                      gensec_gssapi_state->client_name,
 744                                      &name_token,
 745                                      NULL);
 746         if (maj_stat) {
 747                 return NT_STATUS_FOOBAR;
 748         }
 749
 750         principal = talloc_strndup(mem_ctx, name_token.value, name_token.length);
 751
 752         gss_release_buffer(&min_stat, &name_token);
 753
 754         if (!principal) {
 755                 talloc_free(mem_ctx);
 756                 return NT_STATUS_NO_MEMORY;
 757         }
 758
 759         p = strchr(principal, '@');
 760         if (p) {
 761                 *p = '\0';
 762                 p++;
 763                 realm = p;
 764         } else {
 765                 realm = lp_realm();
 766         }
 767         account_name = principal;
 768
 769         maj_stat = gss_krb5_copy_service_keyblock(&min_stat,
 770                                                   gensec_gssapi_state->gssapi_context,
 771                                                   &keyblock);
 772
 773         maj_stat = gsskrb5_extract_authz_data_from_sec_context(&min_stat,
 774                                                                gensec_gssapi_state->gssapi_context,
 775                                                                KRB5_AUTHDATA_IF_RELEVANT,
 776                                                                &pac);
 777
 778         if (maj_stat == 0) {
 779                 DATA_BLOB pac_blob = data_blob_talloc(mem_ctx, pac.value, pac.length);
 780                 pac_blob = unwrap_pac(mem_ctx, &pac_blob);
 781                 gss_release_buffer(&min_stat, &pac);
 782
 783                 /* decode and verify the pac */
 784                 nt_status = kerberos_pac_logon_info(mem_ctx, &logon_info, pac_blob,
 785                                                     gensec_gssapi_state->smb_krb5_context->krb5_context,
 786                                                     NULL, keyblock);
 787
 788                 if (NT_STATUS_IS_OK(nt_status)) {
 789                         union netr_Validation validation;
 790                         validation.sam3 = &logon_info->info3;
 791                         nt_status = make_server_info_netlogon_validation(gensec_gssapi_state,
 792                                                                          account_name,
 793                                                                          3, &validation,
 794                                                                          &server_info);
 795                         if (!NT_STATUS_IS_OK(nt_status)) {
 796                                 talloc_free(mem_ctx);
 797                                 return nt_status;
 798                         }
 799                 } else {
 800                         maj_stat = 1;
 801                 }
 802         }
 803
 804         if (maj_stat) {
 805                 /* IF we have the PAC - otherwise we need to get this
 806                  * data from elsewere - local ldb, or (TODO) lookup of some
 807                  * kind...
 808                  *
 809                  * when heimdal can generate the PAC, we should fail if there's
 810                  * no PAC present
 811                  */
 812
 813                 DATA_BLOB user_sess_key = data_blob(NULL, 0);
 814                 DATA_BLOB lm_sess_key = data_blob(NULL, 0);
 815                 /* TODO: should we pass the krb5 session key in here? */
 816                 nt_status = sam_get_server_info(mem_ctx, account_name, realm,
 817                                                 user_sess_key, lm_sess_key,
 818                                                 &server_info);
 819                 if (!NT_STATUS_IS_OK(nt_status)) {
 820                         talloc_free(mem_ctx);
 821                         return nt_status;
 822                 }
 823         }
 824
 825         /* references the server_info into the session_info */
 826         nt_status = auth_generate_session_info(gensec_gssapi_state, server_info, &session_info);
 827         talloc_free(server_info);
 828         NT_STATUS_NOT_OK_RETURN(nt_status);
 829
 830         nt_status = gensec_gssapi_session_key(gensec_security, &session_info->session_key);
 831         NT_STATUS_NOT_OK_RETURN(nt_status);
 832
 833         *_session_info = session_info;
 834
 835         return NT_STATUS_OK;
 836 }
 837
 838 static const char *gensec_krb5_oids[] = {
 839         GENSEC_OID_KERBEROS5,
 840         GENSEC_OID_KERBEROS5_OLD,
 841         NULL
 842 };
 843
 844 /* As a server, this could in theory accept any GSSAPI mech */
 845 static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
 846         .name           = "gssapi_krb5",
 847         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 848         .oid            = gensec_krb5_oids,
 849         .client_start   = gensec_gssapi_client_start,
 850         .server_start   = gensec_gssapi_server_start,
 851         .magic          = gensec_gssapi_magic,
 852         .update         = gensec_gssapi_update,
 853         .session_key    = gensec_gssapi_session_key,
 854         .session_info   = gensec_gssapi_session_info,
 855         .sig_size       = gensec_gssapi_sig_size,
 856         .sign_packet    = gensec_gssapi_sign_packet,
 857         .check_packet   = gensec_gssapi_check_packet,
 858         .seal_packet    = gensec_gssapi_seal_packet,
 859         .unseal_packet  = gensec_gssapi_unseal_packet,
 860         .wrap           = gensec_gssapi_wrap,
 861         .unwrap         = gensec_gssapi_unwrap,
 862         .have_feature   = gensec_gssapi_have_feature,
 863         .enabled        = False
 864 };
 865
 866 NTSTATUS gensec_gssapi_init(void)
 867 {
 868         NTSTATUS ret;
 869
 870         ret = gensec_register(&gensec_gssapi_krb5_security_ops);
 871         if (!NT_STATUS_IS_OK(ret)) {
 872                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 873                         gensec_gssapi_krb5_security_ops.name));
 874                 return ret;
 875         }
 876
 877         return ret;
 878 }