source4/auth/gensec/gensec_gssapi.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Kerberos backend for GENSEC
   5
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
   7    Copyright (C) Stefan Metzmacher <metze@samba.org> 2004-2005
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23 */
  24
  25 #include "includes.h"
  26 #include "system/kerberos.h"
  27 #include "system/network.h"
  28 #include "auth/kerberos/kerberos.h"
  29 #include "librpc/gen_ndr/ndr_krb5pac.h"
  30 #include "auth/auth.h"
  31
  32 #undef DBGC_CLASS
  33 #define DBGC_CLASS DBGC_AUTH
  34
  35 struct gensec_gssapi_state {
  36         gss_ctx_id_t gssapi_context;
  37         struct gss_channel_bindings_struct *input_chan_bindings;
  38         gss_name_t server_name;
  39         gss_name_t client_name;
  40         OM_uint32 want_flags, got_flags;
  41         const gss_OID_desc *gss_oid;
  42
  43         DATA_BLOB session_key;
  44         DATA_BLOB pac;
  45
  46         struct smb_krb5_context *smb_krb5_context;
  47         krb5_ccache ccache;
  48         const char *ccache_name;
  49         krb5_keytab keytab;
  50
  51         gss_cred_id_t cred;
  52 };
  53
  54 static char *gssapi_error_string(TALLOC_CTX *mem_ctx,
  55                                  OM_uint32 maj_stat, OM_uint32 min_stat)
  56 {
  57         OM_uint32 disp_min_stat, disp_maj_stat;
  58         gss_buffer_desc maj_error_message;
  59         gss_buffer_desc min_error_message;
  60         OM_uint32 msg_ctx = 0;
  61
  62         char *ret;
  63
  64         maj_error_message.value = NULL;
  65         min_error_message.value = NULL;
  66
  67         disp_maj_stat = gss_display_status(&disp_min_stat, maj_stat, GSS_C_GSS_CODE,
  68                            GSS_C_NULL_OID, &msg_ctx, &maj_error_message);
  69         disp_maj_stat = gss_display_status(&disp_min_stat, min_stat, GSS_C_MECH_CODE,
  70                            GSS_C_NULL_OID, &msg_ctx, &min_error_message);
  71         ret = talloc_asprintf(mem_ctx, "%s: %s", (char *)maj_error_message.value, (char *)min_error_message.value);
  72
  73         gss_release_buffer(&disp_min_stat, &maj_error_message);
  74         gss_release_buffer(&disp_min_stat, &min_error_message);
  75
  76         return ret;
  77 }
  78
  79
  80 static int gensec_gssapi_destory(void *ptr)
  81 {
  82         struct gensec_gssapi_state *gensec_gssapi_state = ptr;
  83         OM_uint32 maj_stat, min_stat;
  84
  85         if (gensec_gssapi_state->cred != GSS_C_NO_CREDENTIAL) {
  86                 maj_stat = gss_release_cred(&min_stat,
  87                                             &gensec_gssapi_state->cred);
  88         }
  89
  90         if (gensec_gssapi_state->gssapi_context != GSS_C_NO_CONTEXT) {
  91                 maj_stat = gss_delete_sec_context (&min_stat,
  92                                                    &gensec_gssapi_state->gssapi_context,
  93                                                    GSS_C_NO_BUFFER);
  94         }
  95
  96         if (gensec_gssapi_state->server_name != GSS_C_NO_NAME) {
  97                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->server_name);
  98         }
  99         if (gensec_gssapi_state->client_name != GSS_C_NO_NAME) {
 100                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->client_name);
 101         }
 102         return 0;
 103 }
 104
 105 static NTSTATUS gensec_gssapi_start(struct gensec_security *gensec_security)
 106 {
 107         struct gensec_gssapi_state *gensec_gssapi_state;
 108         krb5_error_code ret;
 109
 110         gensec_gssapi_state = talloc(gensec_security, struct gensec_gssapi_state);
 111         if (!gensec_gssapi_state) {
 112                 return NT_STATUS_NO_MEMORY;
 113         }
 114
 115         gensec_security->private_data = gensec_gssapi_state;
 116
 117         gensec_gssapi_state->gssapi_context = GSS_C_NO_CONTEXT;
 118         gensec_gssapi_state->server_name = GSS_C_NO_NAME;
 119         gensec_gssapi_state->client_name = GSS_C_NO_NAME;
 120
 121         /* TODO: Fill in channel bindings */
 122         gensec_gssapi_state->input_chan_bindings = GSS_C_NO_CHANNEL_BINDINGS;
 123
 124         gensec_gssapi_state->want_flags = 0;
 125         gensec_gssapi_state->got_flags = 0;
 126
 127         gensec_gssapi_state->session_key = data_blob(NULL, 0);
 128         gensec_gssapi_state->pac = data_blob(NULL, 0);
 129
 130         gensec_gssapi_state->cred = GSS_C_NO_CREDENTIAL;
 131
 132         talloc_set_destructor(gensec_gssapi_state, gensec_gssapi_destory);
 133
 134         if (gensec_security->want_features & GENSEC_FEATURE_SESSION_KEY) {
 135 #ifndef HAVE_GSSKRB5_GET_INITIATOR_SUBKEY
 136                 /* GSSAPI won't give us the session keys, without the
 137                  * right hooks.  This is critical when requested, so
 138                  * fail outright. */
 139                 return NT_STATUS_INVALID_PARAMETER;
 140 #endif
 141         }
 142         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 143                 gensec_gssapi_state->want_flags |= GSS_C_INTEG_FLAG;
 144         }
 145         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 146                 gensec_gssapi_state->want_flags |= GSS_C_CONF_FLAG;
 147         }
 148         if (gensec_security->want_features & GENSEC_FEATURE_DCE_STYLE) {
 149 #ifndef GSS_C_DCE_STYLE
 150                 /* GSSAPI DCE_STYLE is critical when requested, so
 151                  * fail outright */
 152                 return NT_STATUS_INVALID_PARAMETER;
 153 #else
 154                 gensec_gssapi_state->want_flags |= GSS_C_DCE_STYLE;
 155 #endif
 156         }
 157
 158         gensec_gssapi_state->gss_oid = gss_mech_krb5;
 159
 160         ret = smb_krb5_init_context(gensec_gssapi_state,
 161                                     &gensec_gssapi_state->smb_krb5_context);
 162         if (ret) {
 163                 DEBUG(1,("gensec_krb5_start: krb5_init_context failed (%s)\n",
 164                          error_message(ret)));
 165                 return NT_STATUS_INTERNAL_ERROR;
 166         }
 167         return NT_STATUS_OK;
 168 }
 169
 170 static NTSTATUS gensec_gssapi_server_start(struct gensec_security *gensec_security)
 171 {
 172         NTSTATUS nt_status;
 173         OM_uint32 maj_stat, min_stat;
 174         struct gensec_gssapi_state *gensec_gssapi_state;
 175         struct cli_credentials *machine_account;
 176
 177         nt_status = gensec_gssapi_start(gensec_security);
 178         if (!NT_STATUS_IS_OK(nt_status)) {
 179                 return nt_status;
 180         }
 181
 182         gensec_gssapi_state = gensec_security->private_data;
 183
 184         machine_account = cli_credentials_init(gensec_gssapi_state);
 185         cli_credentials_set_conf(machine_account);
 186         nt_status = cli_credentials_set_machine_account(machine_account);
 187
 188         if (!NT_STATUS_IS_OK(nt_status)) {
 189                 DEBUG(3, ("Could not obtain machine account credentials from the local database\n"));
 190                 talloc_free(machine_account);
 191                 return nt_status;
 192         } else {
 193                 nt_status = create_memory_keytab(gensec_gssapi_state,
 194                                                  machine_account,
 195                                                  gensec_gssapi_state->smb_krb5_context,
 196                                                  &gensec_gssapi_state->keytab);
 197                 talloc_free(machine_account);
 198                 if (!NT_STATUS_IS_OK(nt_status)) {
 199                         DEBUG(3, ("Could not create memory keytab!\n"));
 200                         talloc_free(machine_account);
 201                         return nt_status;
 202                 }
 203         }
 204
 205         maj_stat = gsskrb5_acquire_cred(&min_stat,
 206                                         gensec_gssapi_state->keytab, NULL,
 207                                         NULL,
 208                                         GSS_C_INDEFINITE,
 209                                         GSS_C_NULL_OID_SET,
 210                                         GSS_C_ACCEPT,
 211                                         &gensec_gssapi_state->cred,
 212                                         NULL,
 213                                         NULL);
 214         if (maj_stat) {
 215                 DEBUG(1, ("Aquiring acceptor credentails failed: %s\n",
 216                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 217                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 218         }
 219
 220         return NT_STATUS_OK;
 221
 222 }
 223
 224 static NTSTATUS gensec_gssapi_client_start(struct gensec_security *gensec_security)
 225 {
 226         struct gensec_gssapi_state *gensec_gssapi_state;
 227         struct cli_credentials *creds = gensec_get_credentials(gensec_security);
 228         NTSTATUS nt_status;
 229         gss_buffer_desc name_token;
 230         OM_uint32 maj_stat, min_stat;
 231         const char *hostname = gensec_get_target_hostname(gensec_security);
 232
 233         if (!hostname) {
 234                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 235                 return NT_STATUS_INVALID_PARAMETER;
 236         }
 237         if (is_ipaddress(hostname)) {
 238                 DEBUG(2, ("Cannot do GSSAPI to a IP address"));
 239                 return NT_STATUS_INVALID_PARAMETER;
 240         }
 241
 242         nt_status = gensec_gssapi_start(gensec_security);
 243         if (!NT_STATUS_IS_OK(nt_status)) {
 244                 return nt_status;
 245         }
 246
 247         gensec_gssapi_state = gensec_security->private_data;
 248
 249         name_token.value = talloc_asprintf(gensec_gssapi_state, "%s@%s",
 250                                            gensec_get_target_service(gensec_security),
 251                                            hostname);
 252         name_token.length = strlen(name_token.value);
 253
 254         maj_stat = gss_import_name (&min_stat,
 255                                     &name_token,
 256                                     GSS_C_NT_HOSTBASED_SERVICE,
 257                                     &gensec_gssapi_state->server_name);
 258         if (maj_stat) {
 259                 DEBUG(1, ("GSS Import name of %s failed: %s\n",
 260                           (char *)name_token.value,
 261                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 262                 return NT_STATUS_UNSUCCESSFUL;
 263         }
 264
 265         name_token.value = cli_credentials_get_principal(creds,
 266                                                          gensec_gssapi_state);
 267         name_token.length = strlen(name_token.value);
 268
 269         maj_stat = gss_import_name (&min_stat,
 270                                     &name_token,
 271                                     GSS_C_NT_USER_NAME,
 272                                     &gensec_gssapi_state->client_name);
 273         if (maj_stat) {
 274                 DEBUG(1, ("GSS Import name of %s failed: %s\n",
 275                           (char *)name_token.value,
 276                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 277                 return NT_STATUS_UNSUCCESSFUL;
 278         }
 279
 280         nt_status = kinit_to_ccache(gensec_gssapi_state,
 281                                     creds,
 282                                     gensec_gssapi_state->smb_krb5_context,
 283                                     &gensec_gssapi_state->ccache, &gensec_gssapi_state->ccache_name);
 284         if (!NT_STATUS_IS_OK(nt_status)) {
 285                 return nt_status;
 286         }
 287
 288         maj_stat = gsskrb5_acquire_cred(&min_stat,
 289                                         NULL, gensec_gssapi_state->ccache,
 290                                         gensec_gssapi_state->client_name,
 291                                         GSS_C_INDEFINITE,
 292                                         GSS_C_NULL_OID_SET,
 293                                         GSS_C_INITIATE,
 294                                         &gensec_gssapi_state->cred,
 295                                         NULL,
 296                                         NULL);
 297         if (maj_stat) {
 298                 DEBUG(1, ("Aquiring initiator credentails failed: %s\n",
 299                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 300                 return NT_STATUS_UNSUCCESSFUL;
 301         }
 302
 303         return NT_STATUS_OK;
 304 }
 305
 306
 307 /**
 308  * Check if the packet is one for this mechansim
 309  *
 310  * @param gensec_security GENSEC state
 311  * @param in The request, as a DATA_BLOB
 312  * @return Error, INVALID_PARAMETER if it's not a packet for us
 313  *                or NT_STATUS_OK if the packet is ok.
 314  */
 315
 316 static NTSTATUS gensec_gssapi_magic(struct gensec_security *gensec_security,
 317                                     const DATA_BLOB *in)
 318 {
 319         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 320                 return NT_STATUS_OK;
 321         } else {
 322                 return NT_STATUS_INVALID_PARAMETER;
 323         }
 324 }
 325
 326
 327 /**
 328  * Next state function for the GSSAPI GENSEC mechanism
 329  *
 330  * @param gensec_gssapi_state GSSAPI State
 331  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 332  * @param in The request, as a DATA_BLOB
 333  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 334  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 335  *                or NT_STATUS_OK if the user is authenticated.
 336  */
 337
 338 static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 339                                    TALLOC_CTX *out_mem_ctx,
 340                                    const DATA_BLOB in, DATA_BLOB *out)
 341 {
 342         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 343         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 344         OM_uint32 maj_stat, min_stat;
 345         OM_uint32 min_stat2;
 346         gss_buffer_desc input_token, output_token;
 347         gss_OID gss_oid_p;
 348         input_token.length = in.length;
 349         input_token.value = in.data;
 350
 351         switch (gensec_security->gensec_role) {
 352         case GENSEC_CLIENT:
 353         {
 354                 maj_stat = gss_init_sec_context(&min_stat,
 355                                                 gensec_gssapi_state->cred,
 356                                                 &gensec_gssapi_state->gssapi_context,
 357                                                 gensec_gssapi_state->server_name,
 358                                                 discard_const_p(gss_OID_desc, gensec_gssapi_state->gss_oid),
 359                                                 gensec_gssapi_state->want_flags,
 360                                                 0,
 361                                                 gensec_gssapi_state->input_chan_bindings,
 362                                                 &input_token,
 363                                                 NULL,
 364                                                 &output_token,
 365                                                 &gensec_gssapi_state->got_flags, /* ret flags */
 366                                                 NULL);
 367                 break;
 368         }
 369         case GENSEC_SERVER:
 370         {
 371                 maj_stat = gss_accept_sec_context(&min_stat,
 372                                                   &gensec_gssapi_state->gssapi_context,
 373                                                   gensec_gssapi_state->cred,
 374                                                   &input_token,
 375                                                   gensec_gssapi_state->input_chan_bindings,
 376                                                   &gensec_gssapi_state->client_name,
 377                                                   &gss_oid_p,
 378                                                   &output_token,
 379                                                   &gensec_gssapi_state->got_flags,
 380                                                   NULL,
 381                                                   NULL);
 382                 gensec_gssapi_state->gss_oid = gss_oid_p;
 383                 break;
 384         }
 385         default:
 386                 return NT_STATUS_INVALID_PARAMETER;
 387
 388         }
 389
 390         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 391         gss_release_buffer(&min_stat2, &output_token);
 392
 393         if (maj_stat == GSS_S_COMPLETE) {
 394                 return NT_STATUS_OK;
 395         } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 396                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 397         } else {
 398                 if (maj_stat == GSS_S_FAILURE
 399                     && (min_stat == KRB5KRB_AP_ERR_BADVERSION || min_stat == KRB5KRB_AP_ERR_MSG_TYPE)) {
 400                         /* garbage input, possibly from the auto-mech detection */
 401                         return NT_STATUS_INVALID_PARAMETER;
 402                 }
 403                 DEBUG(1, ("GSS Update failed: %s\n",
 404                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 405                 return nt_status;
 406         }
 407 }
 408
 409 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 410                                    TALLOC_CTX *mem_ctx,
 411                                    const DATA_BLOB *in,
 412                                    DATA_BLOB *out)
 413 {
 414         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 415         OM_uint32 maj_stat, min_stat;
 416         gss_buffer_desc input_token, output_token;
 417         int conf_state;
 418         input_token.length = in->length;
 419         input_token.value = in->data;
 420
 421         maj_stat = gss_wrap(&min_stat,
 422                             gensec_gssapi_state->gssapi_context,
 423                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 424                             GSS_C_QOP_DEFAULT,
 425                             &input_token,
 426                             &conf_state,
 427                             &output_token);
 428         if (GSS_ERROR(maj_stat)) {
 429                 DEBUG(1, ("GSS Wrap failed: %s\n",
 430                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 431                 return NT_STATUS_ACCESS_DENIED;
 432         }
 433         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 434
 435         gss_release_buffer(&min_stat, &output_token);
 436
 437         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 438             && !conf_state) {
 439                 return NT_STATUS_ACCESS_DENIED;
 440         }
 441         return NT_STATUS_OK;
 442 }
 443
 444 static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 445                                      TALLOC_CTX *mem_ctx,
 446                                      const DATA_BLOB *in,
 447                                      DATA_BLOB *out)
 448 {
 449         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 450         OM_uint32 maj_stat, min_stat;
 451         gss_buffer_desc input_token, output_token;
 452         int conf_state;
 453         gss_qop_t qop_state;
 454         input_token.length = in->length;
 455         input_token.value = in->data;
 456
 457         maj_stat = gss_unwrap(&min_stat,
 458                               gensec_gssapi_state->gssapi_context,
 459                               &input_token,
 460                               &output_token,
 461                               &conf_state,
 462                               &qop_state);
 463         if (GSS_ERROR(maj_stat)) {
 464                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 465                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 466                 return NT_STATUS_ACCESS_DENIED;
 467         }
 468         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 469
 470         gss_release_buffer(&min_stat, &output_token);
 471
 472         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 473             && !conf_state) {
 474                 return NT_STATUS_ACCESS_DENIED;
 475         }
 476         return NT_STATUS_OK;
 477 }
 478
 479 static size_t gensec_gssapi_sig_size(struct gensec_security *gensec_security)
 480 {
 481         /* not const but work for DCERPC packets and arcfour */
 482         return 45;
 483 }
 484
 485 static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_security,
 486                                           TALLOC_CTX *mem_ctx,
 487                                           uint8_t *data, size_t length,
 488                                           const uint8_t *whole_pdu, size_t pdu_length,
 489                                           DATA_BLOB *sig)
 490 {
 491         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 492         OM_uint32 maj_stat, min_stat;
 493         gss_buffer_desc input_token, output_token;
 494         int conf_state;
 495         ssize_t sig_length = 0;
 496
 497         input_token.length = length;
 498         input_token.value = data;
 499
 500         maj_stat = gss_wrap(&min_stat,
 501                             gensec_gssapi_state->gssapi_context,
 502                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 503                             GSS_C_QOP_DEFAULT,
 504                             &input_token,
 505                             &conf_state,
 506                             &output_token);
 507         if (GSS_ERROR(maj_stat)) {
 508                 DEBUG(1, ("GSS Wrap failed: %s\n",
 509                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 510                 return NT_STATUS_ACCESS_DENIED;
 511         }
 512
 513         if (output_token.length < length) {
 514                 return NT_STATUS_INTERNAL_ERROR;
 515         }
 516
 517         sig_length = 45;
 518
 519         memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);
 520         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 521
 522         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 523         dump_data_pw("gensec_gssapi_seal_packet: clear\n", data, length);
 524         dump_data_pw("gensec_gssapi_seal_packet: sealed\n", ((uint8_t *)output_token.value) + sig_length, output_token.length - sig_length);
 525
 526         gss_release_buffer(&min_stat, &output_token);
 527
 528         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 529             && !conf_state) {
 530                 return NT_STATUS_ACCESS_DENIED;
 531         }
 532         return NT_STATUS_OK;
 533 }
 534
 535 static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_security,
 536                                             TALLOC_CTX *mem_ctx,
 537                                             uint8_t *data, size_t length,
 538                                             const uint8_t *whole_pdu, size_t pdu_length,
 539                                             const DATA_BLOB *sig)
 540 {
 541         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 542         OM_uint32 maj_stat, min_stat;
 543         gss_buffer_desc input_token, output_token;
 544         int conf_state;
 545         gss_qop_t qop_state;
 546         DATA_BLOB in;
 547
 548         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 549
 550         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 551
 552         memcpy(in.data, sig->data, sig->length);
 553         memcpy(in.data + sig->length, data, length);
 554
 555         input_token.length = in.length;
 556         input_token.value = in.data;
 557
 558         maj_stat = gss_unwrap(&min_stat,
 559                               gensec_gssapi_state->gssapi_context,
 560                               &input_token,
 561                               &output_token,
 562                               &conf_state,
 563                               &qop_state);
 564         if (GSS_ERROR(maj_stat)) {
 565                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 566                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 567                 return NT_STATUS_ACCESS_DENIED;
 568         }
 569
 570         if (output_token.length != length) {
 571                 return NT_STATUS_INTERNAL_ERROR;
 572         }
 573
 574         memcpy(data, output_token.value, length);
 575
 576         gss_release_buffer(&min_stat, &output_token);
 577
 578         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 579             && !conf_state) {
 580                 return NT_STATUS_ACCESS_DENIED;
 581         }
 582         return NT_STATUS_OK;
 583 }
 584
 585 static NTSTATUS gensec_gssapi_sign_packet(struct gensec_security *gensec_security,
 586                                           TALLOC_CTX *mem_ctx,
 587                                           const uint8_t *data, size_t length,
 588                                           const uint8_t *whole_pdu, size_t pdu_length,
 589                                           DATA_BLOB *sig)
 590 {
 591         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 592         OM_uint32 maj_stat, min_stat;
 593         gss_buffer_desc input_token, output_token;
 594         int conf_state;
 595         ssize_t sig_length = 0;
 596
 597         input_token.length = length;
 598         input_token.value = discard_const_p(uint8_t *, data);
 599
 600         maj_stat = gss_wrap(&min_stat,
 601                             gensec_gssapi_state->gssapi_context,
 602                             0,
 603                             GSS_C_QOP_DEFAULT,
 604                             &input_token,
 605                             &conf_state,
 606                             &output_token);
 607         if (GSS_ERROR(maj_stat)) {
 608                 DEBUG(1, ("GSS Wrap failed: %s\n",
 609                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 610                 return NT_STATUS_ACCESS_DENIED;
 611         }
 612
 613         if (output_token.length < length) {
 614                 return NT_STATUS_INTERNAL_ERROR;
 615         }
 616
 617         sig_length = 45;
 618
 619         /*memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);*/
 620         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 621
 622         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 623
 624         gss_release_buffer(&min_stat, &output_token);
 625
 626         return NT_STATUS_OK;
 627 }
 628
 629 static NTSTATUS gensec_gssapi_check_packet(struct gensec_security *gensec_security,
 630                                            TALLOC_CTX *mem_ctx,
 631                                            const uint8_t *data, size_t length,
 632                                            const uint8_t *whole_pdu, size_t pdu_length,
 633                                            const DATA_BLOB *sig)
 634 {
 635         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 636         OM_uint32 maj_stat, min_stat;
 637         gss_buffer_desc input_token, output_token;
 638         int conf_state;
 639         gss_qop_t qop_state;
 640         DATA_BLOB in;
 641
 642         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 643
 644         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 645
 646         memcpy(in.data, sig->data, sig->length);
 647         memcpy(in.data + sig->length, data, length);
 648
 649         input_token.length = in.length;
 650         input_token.value = in.data;
 651
 652         maj_stat = gss_unwrap(&min_stat,
 653                               gensec_gssapi_state->gssapi_context,
 654                               &input_token,
 655                               &output_token,
 656                               &conf_state,
 657                               &qop_state);
 658         if (GSS_ERROR(maj_stat)) {
 659                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 660                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 661                 return NT_STATUS_ACCESS_DENIED;
 662         }
 663
 664         if (output_token.length != length) {
 665                 return NT_STATUS_INTERNAL_ERROR;
 666         }
 667
 668         gss_release_buffer(&min_stat, &output_token);
 669
 670         return NT_STATUS_OK;
 671 }
 672
 673 static BOOL gensec_gssapi_have_feature(struct gensec_security *gensec_security,
 674                                        uint32_t feature)
 675 {
 676         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 677         if (feature & GENSEC_FEATURE_SIGN) {
 678                 return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
 679         }
 680         if (feature & GENSEC_FEATURE_SEAL) {
 681                 return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
 682         }
 683         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 684 #ifdef HAVE_GSSKRB5_GET_INITIATOR_SUBKEY
 685                 if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 686                     && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements, gensec_gssapi_state->gss_oid->length) == 0)) {
 687                         return True;
 688                 }
 689 #endif
 690         }
 691         return False;
 692 }
 693
 694 static NTSTATUS gensec_gssapi_session_key(struct gensec_security *gensec_security,
 695                                           DATA_BLOB *session_key)
 696 {
 697         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 698
 699         if (gensec_gssapi_state->session_key.data) {
 700                 *session_key = gensec_gssapi_state->session_key;
 701                 return NT_STATUS_OK;
 702         }
 703
 704 #ifdef HAVE_GSSKRB5_GET_INITIATOR_SUBKEY
 705         /* Ensure we only call this for GSSAPI/krb5, otherwise things could get very ugly */
 706         if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 707             && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 708                        gensec_gssapi_state->gss_oid->length) == 0)) {
 709                 OM_uint32 maj_stat, min_stat;
 710                 gss_buffer_desc skey;
 711
 712                 maj_stat = gsskrb5_get_initiator_subkey(&min_stat,
 713                                                         gensec_gssapi_state->gssapi_context,
 714                                                         &skey);
 715
 716                 if (maj_stat == 0) {
 717                         DEBUG(10, ("Got KRB5 session key of length %d\n",
 718                                    (int)skey.length));
 719                         gensec_gssapi_state->session_key = data_blob_talloc(gensec_gssapi_state,
 720                                                                             skey.value, skey.length);
 721                         *session_key = gensec_gssapi_state->session_key;
 722                         dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 723
 724                         gss_release_buffer(&min_stat, &skey);
 725                         return NT_STATUS_OK;
 726                 }
 727                 return NT_STATUS_NO_USER_SESSION_KEY;
 728         }
 729 #endif
 730
 731         DEBUG(1, ("NO session key for this mech\n"));
 732         return NT_STATUS_NO_USER_SESSION_KEY;
 733 }
 734
 735 static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_security,
 736                                          struct auth_session_info **_session_info)
 737 {
 738         NTSTATUS nt_status;
 739         TALLOC_CTX *mem_ctx;
 740         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 741         struct auth_serversupplied_info *server_info = NULL;
 742         struct auth_session_info *session_info = NULL;
 743         struct PAC_LOGON_INFO *logon_info;
 744         char *p;
 745         char *principal;
 746         const char *account_name;
 747         const char *realm;
 748         OM_uint32 maj_stat, min_stat;
 749         gss_buffer_desc name_token;
 750         gss_buffer_desc pac;
 751         krb5_keyblock *keyblock;
 752
 753         mem_ctx = talloc_named(gensec_gssapi_state, 0, "gensec_gssapi_session_info context");
 754         NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
 755
 756         maj_stat = gss_display_name (&min_stat,
 757                                      gensec_gssapi_state->client_name,
 758                                      &name_token,
 759                                      NULL);
 760         if (maj_stat) {
 761                 return NT_STATUS_FOOBAR;
 762         }
 763
 764         principal = talloc_strndup(mem_ctx, name_token.value, name_token.length);
 765
 766         gss_release_buffer(&min_stat, &name_token);
 767
 768         if (!principal) {
 769                 talloc_free(mem_ctx);
 770                 return NT_STATUS_NO_MEMORY;
 771         }
 772
 773         p = strchr(principal, '@');
 774         if (p) {
 775                 *p = '\0';
 776                 p++;
 777                 realm = p;
 778         } else {
 779                 realm = lp_realm();
 780         }
 781         account_name = principal;
 782
 783         maj_stat = gss_krb5_copy_service_keyblock(&min_stat,
 784                                                   gensec_gssapi_state->gssapi_context,
 785                                                   &keyblock);
 786
 787         maj_stat = gsskrb5_extract_authz_data_from_sec_context(&min_stat,
 788                                                                gensec_gssapi_state->gssapi_context,
 789                                                                KRB5_AUTHDATA_IF_RELEVANT,
 790                                                                &pac);
 791
 792         if (maj_stat == 0) {
 793                 DATA_BLOB pac_blob = data_blob_talloc(mem_ctx, pac.value, pac.length);
 794                 pac_blob = unwrap_pac(mem_ctx, &pac_blob);
 795                 gss_release_buffer(&min_stat, &pac);
 796
 797                 /* decode and verify the pac */
 798                 nt_status = kerberos_decode_pac(mem_ctx, &logon_info, pac_blob,
 799                                                 gensec_gssapi_state->smb_krb5_context,
 800                                                 NULL, keyblock);
 801
 802                 if (NT_STATUS_IS_OK(nt_status)) {
 803                         union netr_Validation validation;
 804                         validation.sam3 = &logon_info->info3;
 805                         nt_status = make_server_info_netlogon_validation(gensec_gssapi_state,
 806                                                                          account_name,
 807                                                                          3, &validation,
 808                                                                          &server_info);
 809                         if (!NT_STATUS_IS_OK(nt_status)) {
 810                                 talloc_free(mem_ctx);
 811                                 return nt_status;
 812                         }
 813                 } else {
 814                         maj_stat = 1;
 815                 }
 816         }
 817
 818         if (maj_stat) {
 819                 /* IF we have the PAC - otherwise we need to get this
 820                  * data from elsewere - local ldb, or (TODO) lookup of some
 821                  * kind...
 822                  *
 823                  * when heimdal can generate the PAC, we should fail if there's
 824                  * no PAC present
 825                  */
 826
 827                 DATA_BLOB user_sess_key = data_blob(NULL, 0);
 828                 DATA_BLOB lm_sess_key = data_blob(NULL, 0);
 829                 /* TODO: should we pass the krb5 session key in here? */
 830                 nt_status = sam_get_server_info(mem_ctx, account_name, realm,
 831                                                 user_sess_key, lm_sess_key,
 832                                                 &server_info);
 833                 if (!NT_STATUS_IS_OK(nt_status)) {
 834                         talloc_free(mem_ctx);
 835                         return nt_status;
 836                 }
 837         }
 838
 839         /* references the server_info into the session_info */
 840         nt_status = auth_generate_session_info(gensec_gssapi_state, server_info, &session_info);
 841         talloc_free(server_info);
 842         NT_STATUS_NOT_OK_RETURN(nt_status);
 843
 844         nt_status = gensec_gssapi_session_key(gensec_security, &session_info->session_key);
 845         NT_STATUS_NOT_OK_RETURN(nt_status);
 846
 847         *_session_info = session_info;
 848
 849         return NT_STATUS_OK;
 850 }
 851
 852 static const char *gensec_krb5_oids[] = {
 853         GENSEC_OID_KERBEROS5,
 854         GENSEC_OID_KERBEROS5_OLD,
 855         NULL
 856 };
 857
 858 /* As a server, this could in theory accept any GSSAPI mech */
 859 static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
 860         .name           = "gssapi_krb5",
 861         .oid            = gensec_krb5_oids,
 862         .client_start   = gensec_gssapi_client_start,
 863         .server_start   = gensec_gssapi_server_start,
 864         .magic          = gensec_gssapi_magic,
 865         .update         = gensec_gssapi_update,
 866         .session_key    = gensec_gssapi_session_key,
 867         .session_info   = gensec_gssapi_session_info,
 868         .sig_size       = gensec_gssapi_sig_size,
 869         .sign_packet    = gensec_gssapi_sign_packet,
 870         .check_packet   = gensec_gssapi_check_packet,
 871         .seal_packet    = gensec_gssapi_seal_packet,
 872         .unseal_packet  = gensec_gssapi_unseal_packet,
 873         .wrap           = gensec_gssapi_wrap,
 874         .unwrap         = gensec_gssapi_unwrap,
 875         .have_feature   = gensec_gssapi_have_feature,
 876         .enabled        = False
 877 };
 878
 879 NTSTATUS gensec_gssapi_init(void)
 880 {
 881         NTSTATUS ret;
 882
 883         ret = gensec_register(&gensec_gssapi_krb5_security_ops);
 884         if (!NT_STATUS_IS_OK(ret)) {
 885                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 886                         gensec_gssapi_krb5_security_ops.name));
 887                 return ret;
 888         }
 889
 890         return ret;
 891 }