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         struct keytab_container *keytab;
  47         struct gssapi_creds_container *client_cred;
  48
  49         gss_cred_id_t cred;
  50         gss_cred_id_t delegated_cred_handle;
  51 };
  52
  53 static char *gssapi_error_string(TALLOC_CTX *mem_ctx,
  54                                  OM_uint32 maj_stat, OM_uint32 min_stat)
  55 {
  56         OM_uint32 disp_min_stat, disp_maj_stat;
  57         gss_buffer_desc maj_error_message;
  58         gss_buffer_desc min_error_message;
  59         OM_uint32 msg_ctx = 0;
  60
  61         char *ret;
  62
  63         maj_error_message.value = NULL;
  64         min_error_message.value = NULL;
  65
  66         disp_maj_stat = gss_display_status(&disp_min_stat, maj_stat, GSS_C_GSS_CODE,
  67                            GSS_C_NULL_OID, &msg_ctx, &maj_error_message);
  68         disp_maj_stat = gss_display_status(&disp_min_stat, min_stat, GSS_C_MECH_CODE,
  69                            GSS_C_NULL_OID, &msg_ctx, &min_error_message);
  70         ret = talloc_asprintf(mem_ctx, "%s: %s", (char *)maj_error_message.value, (char *)min_error_message.value);
  71
  72         gss_release_buffer(&disp_min_stat, &maj_error_message);
  73         gss_release_buffer(&disp_min_stat, &min_error_message);
  74
  75         return ret;
  76 }
  77
  78
  79 static int gensec_gssapi_destory(void *ptr)
  80 {
  81         struct gensec_gssapi_state *gensec_gssapi_state = ptr;
  82         OM_uint32 maj_stat, min_stat;
  83
  84         if (gensec_gssapi_state->cred != GSS_C_NO_CREDENTIAL) {
  85                 maj_stat = gss_release_cred(&min_stat,
  86                                             &gensec_gssapi_state->cred);
  87         }
  88         if (gensec_gssapi_state->delegated_cred_handle != GSS_C_NO_CREDENTIAL) {
  89                 maj_stat = gss_release_cred(&min_stat,
  90                                             &gensec_gssapi_state->delegated_cred_handle);
  91         }
  92
  93         if (gensec_gssapi_state->gssapi_context != GSS_C_NO_CONTEXT) {
  94                 maj_stat = gss_delete_sec_context (&min_stat,
  95                                                    &gensec_gssapi_state->gssapi_context,
  96                                                    GSS_C_NO_BUFFER);
  97         }
  98
  99         if (gensec_gssapi_state->server_name != GSS_C_NO_NAME) {
 100                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->server_name);
 101         }
 102         if (gensec_gssapi_state->client_name != GSS_C_NO_NAME) {
 103                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->client_name);
 104         }
 105         return 0;
 106 }
 107
 108 static NTSTATUS gensec_gssapi_start(struct gensec_security *gensec_security)
 109 {
 110         struct gensec_gssapi_state *gensec_gssapi_state;
 111         krb5_error_code ret;
 112
 113         gensec_gssapi_state = talloc(gensec_security, struct gensec_gssapi_state);
 114         if (!gensec_gssapi_state) {
 115                 return NT_STATUS_NO_MEMORY;
 116         }
 117
 118         gensec_security->private_data = gensec_gssapi_state;
 119
 120         gensec_gssapi_state->gssapi_context = GSS_C_NO_CONTEXT;
 121         gensec_gssapi_state->server_name = GSS_C_NO_NAME;
 122         gensec_gssapi_state->client_name = GSS_C_NO_NAME;
 123
 124         /* TODO: Fill in channel bindings */
 125         gensec_gssapi_state->input_chan_bindings = GSS_C_NO_CHANNEL_BINDINGS;
 126
 127         gensec_gssapi_state->want_flags = GSS_C_MUTUAL_FLAG | GSS_C_DELEG_FLAG;
 128         gensec_gssapi_state->got_flags = 0;
 129
 130         gensec_gssapi_state->session_key = data_blob(NULL, 0);
 131         gensec_gssapi_state->pac = data_blob(NULL, 0);
 132
 133         gensec_gssapi_state->cred = GSS_C_NO_CREDENTIAL;
 134         gensec_gssapi_state->delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 135
 136         talloc_set_destructor(gensec_gssapi_state, gensec_gssapi_destory);
 137
 138         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 139                 gensec_gssapi_state->want_flags |= GSS_C_INTEG_FLAG;
 140         }
 141         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 142                 gensec_gssapi_state->want_flags |= GSS_C_CONF_FLAG;
 143         }
 144         if (gensec_security->want_features & GENSEC_FEATURE_DCE_STYLE) {
 145                 gensec_gssapi_state->want_flags |= GSS_C_DCE_STYLE;
 146         }
 147
 148         gensec_gssapi_state->gss_oid = gss_mech_krb5;
 149
 150         ret = smb_krb5_init_context(gensec_gssapi_state,
 151                                     &gensec_gssapi_state->smb_krb5_context);
 152         if (ret) {
 153                 DEBUG(1,("gensec_krb5_start: krb5_init_context failed (%s)\n",
 154                          error_message(ret)));
 155                 return NT_STATUS_INTERNAL_ERROR;
 156         }
 157         return NT_STATUS_OK;
 158 }
 159
 160 static NTSTATUS gensec_gssapi_server_start(struct gensec_security *gensec_security)
 161 {
 162         NTSTATUS nt_status;
 163         OM_uint32 maj_stat, min_stat;
 164         int ret;
 165         const char *principal;
 166         struct gensec_gssapi_state *gensec_gssapi_state;
 167         struct cli_credentials *machine_account;
 168
 169         nt_status = gensec_gssapi_start(gensec_security);
 170         if (!NT_STATUS_IS_OK(nt_status)) {
 171                 return nt_status;
 172         }
 173
 174         gensec_gssapi_state = gensec_security->private_data;
 175
 176         machine_account = gensec_get_credentials(gensec_security);
 177
 178         if (!machine_account) {
 179                 DEBUG(3, ("No machine account credentials specified\n"));
 180                 return NT_STATUS_INVALID_PARAMETER;
 181         } else {
 182                 ret = cli_credentials_get_keytab(machine_account, &gensec_gssapi_state->keytab);
 183                 if (ret) {
 184                         DEBUG(3, ("Could not create memory keytab!\n"));
 185                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 186                 }
 187         }
 188
 189         principal = cli_credentials_get_principal(machine_account,
 190                                                   machine_account);
 191
 192         /* This might have been explicity set to NULL, ie use what the client calls us */
 193         if (principal) {
 194                 gss_buffer_desc name_token;
 195
 196                 name_token.value  = discard_const_p(uint8_t, principal);
 197                 name_token.length = strlen(principal);
 198
 199                 maj_stat = gss_import_name (&min_stat,
 200                                             &name_token,
 201                                             GSS_C_NT_USER_NAME,
 202                                             &gensec_gssapi_state->server_name);
 203
 204                 if (maj_stat) {
 205                         DEBUG(2, ("GSS Import name of %s failed: %s\n",
 206                                   (char *)name_token.value,
 207                                   gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 208                         return NT_STATUS_UNSUCCESSFUL;
 209                 }
 210         } else {
 211                 gensec_gssapi_state->server_name = GSS_C_NO_NAME;
 212         }
 213
 214         maj_stat = gsskrb5_acquire_cred(&min_stat,
 215                                         gensec_gssapi_state->keytab->keytab,
 216                                         gensec_gssapi_state->server_name,
 217                                         GSS_C_INDEFINITE,
 218                                         GSS_C_NULL_OID_SET,
 219                                         GSS_C_ACCEPT,
 220                                         &gensec_gssapi_state->cred,
 221                                         NULL,
 222                                         NULL);
 223         if (maj_stat) {
 224                 DEBUG(1, ("Aquiring acceptor credentails failed: %s\n",
 225                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 226                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 227         }
 228
 229         return NT_STATUS_OK;
 230
 231 }
 232
 233 static NTSTATUS gensec_gssapi_client_start(struct gensec_security *gensec_security)
 234 {
 235         struct gensec_gssapi_state *gensec_gssapi_state;
 236         struct cli_credentials *creds = gensec_get_credentials(gensec_security);
 237         krb5_error_code ret;
 238         NTSTATUS nt_status;
 239         gss_buffer_desc name_token;
 240         gss_OID name_type;
 241         OM_uint32 maj_stat, min_stat;
 242         const char *hostname = gensec_get_target_hostname(gensec_security);
 243         const char *principal;
 244         struct gssapi_creds_container *gcc;
 245
 246         if (!hostname) {
 247                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 248                 return NT_STATUS_INVALID_PARAMETER;
 249         }
 250         if (is_ipaddress(hostname)) {
 251                 DEBUG(2, ("Cannot do GSSAPI to an IP address\n"));
 252                 return NT_STATUS_INVALID_PARAMETER;
 253         }
 254         if (strequal(hostname, "localhost")) {
 255                 DEBUG(2, ("GSSAPI to 'localhost' does not make sense\n"));
 256                 return NT_STATUS_INVALID_PARAMETER;
 257         }
 258
 259         nt_status = gensec_gssapi_start(gensec_security);
 260         if (!NT_STATUS_IS_OK(nt_status)) {
 261                 return nt_status;
 262         }
 263
 264         gensec_gssapi_state = gensec_security->private_data;
 265
 266         principal = gensec_get_target_principal(gensec_security);
 267         if (principal && lp_client_use_spnego_principal()) {
 268                 name_token.value  = discard_const_p(uint8_t, principal);
 269                 name_token.length = strlen(principal);
 270
 271                 name_type = GSS_C_NULL_OID;
 272         } else {
 273                 principal = talloc_asprintf(gensec_gssapi_state, "%s@%s",
 274                                             gensec_get_target_service(gensec_security),
 275                                             hostname);
 276
 277                 name_token.value  = discard_const_p(uint8_t, principal);
 278                 name_token.length = strlen(principal);
 279
 280                 name_type = GSS_C_NT_HOSTBASED_SERVICE;
 281         }
 282
 283         maj_stat = gss_import_name (&min_stat,
 284                                     &name_token,
 285                                     name_type,
 286                                     &gensec_gssapi_state->server_name);
 287         if (maj_stat) {
 288                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 289                           (char *)name_token.value,
 290                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 291                 return NT_STATUS_INVALID_PARAMETER;
 292         }
 293
 294         ret = cli_credentials_get_client_gss_creds(creds, &gcc);
 295         switch (ret) {
 296         case 0:
 297                 break;
 298         case KRB5_KDC_UNREACH:
 299                 DEBUG(3, ("Cannot reach a KDC we require\n"));
 300                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 301         default:
 302                 DEBUG(1, ("Aquiring initiator credentails failed\n"));
 303                 return NT_STATUS_UNSUCCESSFUL;
 304         }
 305
 306         gensec_gssapi_state->client_cred = gcc;
 307
 308         return NT_STATUS_OK;
 309 }
 310
 311
 312 /**
 313  * Check if the packet is one for this mechansim
 314  *
 315  * @param gensec_security GENSEC state
 316  * @param in The request, as a DATA_BLOB
 317  * @return Error, INVALID_PARAMETER if it's not a packet for us
 318  *                or NT_STATUS_OK if the packet is ok.
 319  */
 320
 321 static NTSTATUS gensec_gssapi_magic(struct gensec_security *gensec_security,
 322                                     const DATA_BLOB *in)
 323 {
 324         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 325                 return NT_STATUS_OK;
 326         } else {
 327                 return NT_STATUS_INVALID_PARAMETER;
 328         }
 329 }
 330
 331
 332 /**
 333  * Next state function for the GSSAPI GENSEC mechanism
 334  *
 335  * @param gensec_gssapi_state GSSAPI State
 336  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 337  * @param in The request, as a DATA_BLOB
 338  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 339  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 340  *                or NT_STATUS_OK if the user is authenticated.
 341  */
 342
 343 static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 344                                    TALLOC_CTX *out_mem_ctx,
 345                                    const DATA_BLOB in, DATA_BLOB *out)
 346 {
 347         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 348         NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
 349         OM_uint32 maj_stat, min_stat;
 350         OM_uint32 min_stat2;
 351         gss_buffer_desc input_token, output_token;
 352         gss_OID gss_oid_p;
 353         input_token.length = in.length;
 354         input_token.value = in.data;
 355
 356         switch (gensec_security->gensec_role) {
 357         case GENSEC_CLIENT:
 358         {
 359                 maj_stat = gss_init_sec_context(&min_stat,
 360                                                 gensec_gssapi_state->client_cred->creds,
 361                                                 &gensec_gssapi_state->gssapi_context,
 362                                                 gensec_gssapi_state->server_name,
 363                                                 discard_const_p(gss_OID_desc, gensec_gssapi_state->gss_oid),
 364                                                 gensec_gssapi_state->want_flags,
 365                                                 0,
 366                                                 gensec_gssapi_state->input_chan_bindings,
 367                                                 &input_token,
 368                                                 NULL,
 369                                                 &output_token,
 370                                                 &gensec_gssapi_state->got_flags, /* ret flags */
 371                                                 NULL);
 372                 break;
 373         }
 374         case GENSEC_SERVER:
 375         {
 376                 maj_stat = gss_accept_sec_context(&min_stat,
 377                                                   &gensec_gssapi_state->gssapi_context,
 378                                                   gensec_gssapi_state->cred,
 379                                                   &input_token,
 380                                                   gensec_gssapi_state->input_chan_bindings,
 381                                                   &gensec_gssapi_state->client_name,
 382                                                   &gss_oid_p,
 383                                                   &output_token,
 384                                                   &gensec_gssapi_state->got_flags,
 385                                                   NULL,
 386                                                   &gensec_gssapi_state->delegated_cred_handle);
 387                 gensec_gssapi_state->gss_oid = gss_oid_p;
 388                 break;
 389         }
 390         default:
 391                 return NT_STATUS_INVALID_PARAMETER;
 392
 393         }
 394
 395         if (maj_stat == GSS_S_COMPLETE) {
 396                 *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 397                 gss_release_buffer(&min_stat2, &output_token);
 398
 399                 if (gensec_gssapi_state->got_flags & GSS_C_DELEG_FLAG) {
 400                         DEBUG(5, ("gensec_gssapi: credentials were delegated\n"));
 401                 } else {
 402                         DEBUG(5, ("gensec_gssapi: NO credentials were delegated\n"));
 403                 }
 404
 405                 return NT_STATUS_OK;
 406         } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 407                 *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 408                 gss_release_buffer(&min_stat2, &output_token);
 409
 410                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 411         } else if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 412             && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 413                        gensec_gssapi_state->gss_oid->length) == 0)) {
 414                 switch (min_stat) {
 415                 case KRB5_KDC_UNREACH:
 416                         DEBUG(3, ("Cannot reach a KDC we require: %s\n",
 417                                   gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 418                         return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 419                 case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 420                         DEBUG(3, ("Server is not registered with our KDC: %s\n",
 421                                   gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 422                         return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 423                 case KRB5KRB_AP_ERR_MSG_TYPE:
 424                         /* garbage input, possibly from the auto-mech detection */
 425                         return NT_STATUS_INVALID_PARAMETER;
 426                 default:
 427                         DEBUG(1, ("GSS(krb5) Update failed: %s\n",
 428                                   gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 429                         return nt_status;
 430                 }
 431         } else {
 432                 DEBUG(1, ("GSS Update failed: %s\n",
 433                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 434                 return nt_status;
 435         }
 436 }
 437
 438 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 439                                    TALLOC_CTX *mem_ctx,
 440                                    const DATA_BLOB *in,
 441                                    DATA_BLOB *out)
 442 {
 443         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 444         OM_uint32 maj_stat, min_stat;
 445         gss_buffer_desc input_token, output_token;
 446         int conf_state;
 447         input_token.length = in->length;
 448         input_token.value = in->data;
 449
 450         maj_stat = gss_wrap(&min_stat,
 451                             gensec_gssapi_state->gssapi_context,
 452                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 453                             GSS_C_QOP_DEFAULT,
 454                             &input_token,
 455                             &conf_state,
 456                             &output_token);
 457         if (GSS_ERROR(maj_stat)) {
 458                 DEBUG(1, ("gensec_gssapi_wrap: GSS Wrap failed: %s\n",
 459                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 460                 return NT_STATUS_ACCESS_DENIED;
 461         }
 462
 463         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 464         gss_release_buffer(&min_stat, &output_token);
 465
 466         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 467             && !conf_state) {
 468                 return NT_STATUS_ACCESS_DENIED;
 469         }
 470         return NT_STATUS_OK;
 471 }
 472
 473 static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 474                                      TALLOC_CTX *mem_ctx,
 475                                      const DATA_BLOB *in,
 476                                      DATA_BLOB *out)
 477 {
 478         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 479         OM_uint32 maj_stat, min_stat;
 480         gss_buffer_desc input_token, output_token;
 481         int conf_state;
 482         gss_qop_t qop_state;
 483         input_token.length = in->length;
 484         input_token.value = in->data;
 485
 486         maj_stat = gss_unwrap(&min_stat,
 487                               gensec_gssapi_state->gssapi_context,
 488                               &input_token,
 489                               &output_token,
 490                               &conf_state,
 491                               &qop_state);
 492         if (GSS_ERROR(maj_stat)) {
 493                 DEBUG(1, ("gensec_gssapi_unwrap: GSS UnWrap failed: %s\n",
 494                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 495                 return NT_STATUS_ACCESS_DENIED;
 496         }
 497
 498         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 499         gss_release_buffer(&min_stat, &output_token);
 500
 501         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 502             && !conf_state) {
 503                 return NT_STATUS_ACCESS_DENIED;
 504         }
 505         return NT_STATUS_OK;
 506 }
 507
 508 static size_t gensec_gssapi_sig_size(struct gensec_security *gensec_security, size_t data_size)
 509 {
 510         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 511         OM_uint32 maj_stat, min_stat;
 512         OM_uint32 output_size;
 513         if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
 514             || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 515                        gensec_gssapi_state->gss_oid->length) != 0)) {
 516                 DEBUG(1, ("NO sig size available for this mech\n"));
 517                 return 0;
 518         }
 519
 520         maj_stat = gsskrb5_wrap_size(&min_stat,
 521                                      gensec_gssapi_state->gssapi_context,
 522                                      gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 523                                      GSS_C_QOP_DEFAULT,
 524                                      data_size,
 525                                      &output_size);
 526         if (GSS_ERROR(maj_stat)) {
 527                 TALLOC_CTX *mem_ctx = talloc_new(NULL);
 528                 DEBUG(1, ("gensec_gssapi_seal_packet: determinaing signature size with gss_wrap_size_limit failed: %s\n",
 529                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 530                 talloc_free(mem_ctx);
 531                 return 0;
 532         }
 533
 534         if (output_size < data_size) {
 535                 return 0;
 536         }
 537
 538         /* The difference between the max output and the max input must be the signature */
 539         return output_size - data_size;
 540 }
 541
 542 static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_security,
 543                                           TALLOC_CTX *mem_ctx,
 544                                           uint8_t *data, size_t length,
 545                                           const uint8_t *whole_pdu, size_t pdu_length,
 546                                           DATA_BLOB *sig)
 547 {
 548         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 549         OM_uint32 maj_stat, min_stat;
 550         gss_buffer_desc input_token, output_token;
 551         int conf_state;
 552         ssize_t sig_length;
 553
 554         input_token.length = length;
 555         input_token.value = data;
 556
 557         maj_stat = gss_wrap(&min_stat,
 558                             gensec_gssapi_state->gssapi_context,
 559                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 560                             GSS_C_QOP_DEFAULT,
 561                             &input_token,
 562                             &conf_state,
 563                             &output_token);
 564         if (GSS_ERROR(maj_stat)) {
 565                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap failed: %s\n",
 566                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 567                 return NT_STATUS_ACCESS_DENIED;
 568         }
 569
 570         sig_length = gensec_gssapi_sig_size(gensec_security, length);
 571
 572         /* Caller must pad to right boundary */
 573         if (output_token.length != (length + sig_length)) {
 574                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap length [%d] does not match caller length [%d] plus sig size [%d] = [%d]\n",
 575                           output_token.length, length, sig_length, length + sig_length));
 576                 return NT_STATUS_INTERNAL_ERROR;
 577         }
 578
 579         memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);
 580         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 581
 582         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 583         dump_data_pw("gensec_gssapi_seal_packet: clear\n", data, length);
 584         dump_data_pw("gensec_gssapi_seal_packet: sealed\n", ((uint8_t *)output_token.value) + sig_length, output_token.length - sig_length);
 585
 586         gss_release_buffer(&min_stat, &output_token);
 587
 588         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 589             && !conf_state) {
 590                 return NT_STATUS_ACCESS_DENIED;
 591         }
 592         return NT_STATUS_OK;
 593 }
 594
 595 static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_security,
 596                                             TALLOC_CTX *mem_ctx,
 597                                             uint8_t *data, size_t length,
 598                                             const uint8_t *whole_pdu, size_t pdu_length,
 599                                             const DATA_BLOB *sig)
 600 {
 601         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 602         OM_uint32 maj_stat, min_stat;
 603         gss_buffer_desc input_token, output_token;
 604         int conf_state;
 605         gss_qop_t qop_state;
 606         DATA_BLOB in;
 607
 608         dump_data_pw("gensec_gssapi_unseal_packet: sig\n", sig->data, sig->length);
 609
 610         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 611
 612         memcpy(in.data, sig->data, sig->length);
 613         memcpy(in.data + sig->length, data, length);
 614
 615         input_token.length = in.length;
 616         input_token.value = in.data;
 617
 618         maj_stat = gss_unwrap(&min_stat,
 619                               gensec_gssapi_state->gssapi_context,
 620                               &input_token,
 621                               &output_token,
 622                               &conf_state,
 623                               &qop_state);
 624         if (GSS_ERROR(maj_stat)) {
 625                 DEBUG(1, ("gensec_gssapi_unseal_packet: GSS UnWrap failed: %s\n",
 626                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 627                 return NT_STATUS_ACCESS_DENIED;
 628         }
 629
 630         if (output_token.length != length) {
 631                 return NT_STATUS_INTERNAL_ERROR;
 632         }
 633
 634         memcpy(data, output_token.value, length);
 635
 636         gss_release_buffer(&min_stat, &output_token);
 637
 638         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 639             && !conf_state) {
 640                 return NT_STATUS_ACCESS_DENIED;
 641         }
 642         return NT_STATUS_OK;
 643 }
 644
 645 static NTSTATUS gensec_gssapi_sign_packet(struct gensec_security *gensec_security,
 646                                           TALLOC_CTX *mem_ctx,
 647                                           const uint8_t *data, size_t length,
 648                                           const uint8_t *whole_pdu, size_t pdu_length,
 649                                           DATA_BLOB *sig)
 650 {
 651         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 652         OM_uint32 maj_stat, min_stat;
 653         gss_buffer_desc input_token, output_token;
 654         int conf_state;
 655         ssize_t sig_length = 0;
 656
 657         input_token.length = length;
 658         input_token.value = discard_const_p(uint8_t *, data);
 659
 660         maj_stat = gss_wrap(&min_stat,
 661                             gensec_gssapi_state->gssapi_context,
 662                             0,
 663                             GSS_C_QOP_DEFAULT,
 664                             &input_token,
 665                             &conf_state,
 666                             &output_token);
 667         if (GSS_ERROR(maj_stat)) {
 668                 DEBUG(1, ("GSS Wrap failed: %s\n",
 669                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 670                 return NT_STATUS_ACCESS_DENIED;
 671         }
 672
 673         if (output_token.length < length) {
 674                 return NT_STATUS_INTERNAL_ERROR;
 675         }
 676
 677         sig_length = gensec_gssapi_sig_size(gensec_security, length);
 678
 679         /* Caller must pad to right boundary */
 680         if (output_token.length != (length + sig_length)) {
 681                 DEBUG(1, ("gensec_gssapi_sign_packet: GSS Wrap length [%d] does not match caller length [%d] plus sig size [%d] = [%d]\n",
 682                           output_token.length, length, sig_length, length + sig_length));
 683                 return NT_STATUS_INTERNAL_ERROR;
 684         }
 685
 686         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 687
 688         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 689
 690         gss_release_buffer(&min_stat, &output_token);
 691
 692         return NT_STATUS_OK;
 693 }
 694
 695 static NTSTATUS gensec_gssapi_check_packet(struct gensec_security *gensec_security,
 696                                            TALLOC_CTX *mem_ctx,
 697                                            const uint8_t *data, size_t length,
 698                                            const uint8_t *whole_pdu, size_t pdu_length,
 699                                            const DATA_BLOB *sig)
 700 {
 701         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 702         OM_uint32 maj_stat, min_stat;
 703         gss_buffer_desc input_token, output_token;
 704         int conf_state;
 705         gss_qop_t qop_state;
 706         DATA_BLOB in;
 707
 708         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 709
 710         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 711
 712         memcpy(in.data, sig->data, sig->length);
 713         memcpy(in.data + sig->length, data, length);
 714
 715         input_token.length = in.length;
 716         input_token.value = in.data;
 717
 718         maj_stat = gss_unwrap(&min_stat,
 719                               gensec_gssapi_state->gssapi_context,
 720                               &input_token,
 721                               &output_token,
 722                               &conf_state,
 723                               &qop_state);
 724         if (GSS_ERROR(maj_stat)) {
 725                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 726                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 727                 return NT_STATUS_ACCESS_DENIED;
 728         }
 729
 730         if (output_token.length != length) {
 731                 return NT_STATUS_INTERNAL_ERROR;
 732         }
 733
 734         gss_release_buffer(&min_stat, &output_token);
 735
 736         return NT_STATUS_OK;
 737 }
 738
 739 static BOOL gensec_gssapi_have_feature(struct gensec_security *gensec_security,
 740                                        uint32_t feature)
 741 {
 742         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 743         if (feature & GENSEC_FEATURE_SIGN) {
 744                 return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
 745         }
 746         if (feature & GENSEC_FEATURE_SEAL) {
 747                 return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
 748         }
 749         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 750                 if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 751                     && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements, gensec_gssapi_state->gss_oid->length) == 0)) {
 752                         return True;
 753                 }
 754         }
 755         if (feature & GENSEC_FEATURE_DCE_STYLE) {
 756                 return gensec_gssapi_state->got_flags & GSS_C_DCE_STYLE;
 757         }
 758         if (feature & GENSEC_FEATURE_ASYNC_REPLIES) {
 759                 return True;
 760         }
 761         return False;
 762 }
 763
 764 static NTSTATUS gensec_gssapi_session_key(struct gensec_security *gensec_security,
 765                                           DATA_BLOB *session_key)
 766 {
 767         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 768
 769         if (gensec_gssapi_state->session_key.data) {
 770                 *session_key = gensec_gssapi_state->session_key;
 771                 return NT_STATUS_OK;
 772         }
 773
 774         /* Ensure we only call this for GSSAPI/krb5, otherwise things could get very ugly */
 775         if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 776             && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 777                        gensec_gssapi_state->gss_oid->length) == 0)) {
 778                 OM_uint32 maj_stat, min_stat;
 779                 gss_buffer_desc skey;
 780
 781                 maj_stat = gsskrb5_get_initiator_subkey(&min_stat,
 782                                                         gensec_gssapi_state->gssapi_context,
 783                                                         &skey);
 784
 785                 if (maj_stat == 0) {
 786                         DEBUG(10, ("Got KRB5 session key of length %d\n",
 787                                    (int)skey.length));
 788                         gensec_gssapi_state->session_key = data_blob_talloc(gensec_gssapi_state,
 789                                                                             skey.value, skey.length);
 790                         *session_key = gensec_gssapi_state->session_key;
 791                         dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 792
 793                         gss_release_buffer(&min_stat, &skey);
 794                         return NT_STATUS_OK;
 795                 }
 796                 return NT_STATUS_NO_USER_SESSION_KEY;
 797         }
 798
 799         DEBUG(1, ("NO session key for this mech\n"));
 800         return NT_STATUS_NO_USER_SESSION_KEY;
 801 }
 802
 803 static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_security,
 804                                          struct auth_session_info **_session_info)
 805 {
 806         NTSTATUS nt_status;
 807         TALLOC_CTX *mem_ctx;
 808         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 809         struct auth_serversupplied_info *server_info = NULL;
 810         struct auth_session_info *session_info = NULL;
 811         struct PAC_LOGON_INFO *logon_info;
 812         OM_uint32 maj_stat, min_stat;
 813         gss_buffer_desc name_token;
 814         gss_buffer_desc pac;
 815         krb5_keyblock *keyblock;
 816         time_t authtime;
 817         krb5_principal principal;
 818         char *principal_string;
 819         DATA_BLOB pac_blob;
 820
 821         if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
 822             || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 823                        gensec_gssapi_state->gss_oid->length) != 0)) {
 824                 DEBUG(1, ("NO session info available for this mech\n"));
 825                 return NT_STATUS_INVALID_PARAMETER;
 826         }
 827
 828         mem_ctx = talloc_named(gensec_gssapi_state, 0, "gensec_gssapi_session_info context");
 829         NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
 830
 831         maj_stat = gss_display_name (&min_stat,
 832                                      gensec_gssapi_state->client_name,
 833                                      &name_token,
 834                                      NULL);
 835         if (maj_stat) {
 836                 return NT_STATUS_FOOBAR;
 837         }
 838
 839         principal_string = talloc_strndup(mem_ctx, name_token.value, name_token.length);
 840
 841         gss_release_buffer(&min_stat, &name_token);
 842
 843         if (!principal_string) {
 844                 talloc_free(mem_ctx);
 845                 return NT_STATUS_NO_MEMORY;
 846         }
 847
 848         maj_stat = gss_krb5_copy_service_keyblock(&min_stat,
 849                                                   gensec_gssapi_state->gssapi_context,
 850                                                   &keyblock);
 851
 852         if (maj_stat == 0) {
 853                 maj_stat = gsskrb5_extract_authtime_from_sec_context(&min_stat,
 854                                                                      gensec_gssapi_state->gssapi_context,
 855                                                                      &authtime);
 856         }
 857
 858         if (maj_stat == 0) {
 859                 maj_stat = gsskrb5_extract_authz_data_from_sec_context(&min_stat,
 860                                                                        gensec_gssapi_state->gssapi_context,
 861                                                                        KRB5_AUTHDATA_WIN2K_PAC,
 862                                                                        &pac);
 863         }
 864
 865         if (maj_stat == 0) {
 866                 pac_blob = data_blob_talloc(mem_ctx, pac.value, pac.length);
 867                 gss_release_buffer(&min_stat, &pac);
 868         }
 869
 870         /* IF we have the PAC - otherwise we need to get this
 871          * data from elsewere - local ldb, or (TODO) lookup of some
 872          * kind...
 873          */
 874         if (maj_stat == 0) {
 875                 krb5_error_code ret;
 876
 877                 ret = krb5_parse_name(gensec_gssapi_state->smb_krb5_context->krb5_context,
 878                                       principal_string, &principal);
 879                 if (ret) {
 880                         talloc_free(mem_ctx);
 881                         return NT_STATUS_INVALID_PARAMETER;
 882                 }
 883
 884                 /* decode and verify the pac */
 885                 nt_status = kerberos_pac_logon_info(mem_ctx, &logon_info, pac_blob,
 886                                                     gensec_gssapi_state->smb_krb5_context->krb5_context,
 887                                                     NULL, keyblock, principal, authtime);
 888                 krb5_free_principal(gensec_gssapi_state->smb_krb5_context->krb5_context, principal);
 889
 890                 if (NT_STATUS_IS_OK(nt_status)) {
 891                         union netr_Validation validation;
 892                         validation.sam3 = &logon_info->info3;
 893                         nt_status = make_server_info_netlogon_validation(gensec_gssapi_state,
 894                                                                          NULL,
 895                                                                          3, &validation,
 896                                                                          &server_info);
 897                         if (!NT_STATUS_IS_OK(nt_status)) {
 898                                 talloc_free(mem_ctx);
 899                                 return nt_status;
 900                         }
 901                 } else {
 902                         maj_stat = 1;
 903                 }
 904         }
 905
 906         if (maj_stat) {
 907                 DEBUG(1, ("Unable to use PAC, resorting to local user lookup!\n"));
 908                 nt_status = sam_get_server_info_principal(mem_ctx, principal_string,
 909                                                           &server_info);
 910
 911                 if (!NT_STATUS_IS_OK(nt_status)) {
 912                         talloc_free(mem_ctx);
 913                         return nt_status;
 914                 }
 915         }
 916
 917         /* references the server_info into the session_info */
 918         nt_status = auth_generate_session_info(gensec_gssapi_state, server_info, &session_info);
 919         talloc_free(mem_ctx);
 920         talloc_free(server_info);
 921         NT_STATUS_NOT_OK_RETURN(nt_status);
 922
 923         nt_status = gensec_gssapi_session_key(gensec_security, &session_info->session_key);
 924         NT_STATUS_NOT_OK_RETURN(nt_status);
 925
 926         if (!(gensec_gssapi_state->got_flags & GSS_C_DELEG_FLAG)) {
 927                 DEBUG(10, ("gensec_gssapi: NO delegated credentials supplied by client"));
 928         } else {
 929                 krb5_error_code ret;
 930                 DEBUG(10, ("gensec_gssapi: delegated credentials supplied by client\n"));
 931                 session_info->credentials = cli_credentials_init(session_info);
 932                 if (!session_info->credentials) {
 933                         return NT_STATUS_NO_MEMORY;
 934                 }
 935
 936                 cli_credentials_set_conf(session_info->credentials);
 937
 938                 ret = cli_credentials_set_client_gss_creds(session_info->credentials,
 939                                                            gensec_gssapi_state->delegated_cred_handle,
 940                                                            CRED_SPECIFIED);
 941                 if (ret) {
 942                         return NT_STATUS_NO_MEMORY;
 943                 }
 944                 /* It has been taken from this place... */
 945                 gensec_gssapi_state->delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 946         }
 947         *_session_info = session_info;
 948
 949         return NT_STATUS_OK;
 950 }
 951
 952 static const char *gensec_gssapi_krb5_oids[] = {
 953         GENSEC_OID_KERBEROS5,
 954         GENSEC_OID_KERBEROS5_OLD,
 955         NULL
 956 };
 957
 958 /* As a server, this could in theory accept any GSSAPI mech */
 959 static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
 960         .name           = "gssapi_krb5",
 961         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 962         .oid            = gensec_gssapi_krb5_oids,
 963         .client_start   = gensec_gssapi_client_start,
 964         .server_start   = gensec_gssapi_server_start,
 965         .magic          = gensec_gssapi_magic,
 966         .update         = gensec_gssapi_update,
 967         .session_key    = gensec_gssapi_session_key,
 968         .session_info   = gensec_gssapi_session_info,
 969         .sig_size       = gensec_gssapi_sig_size,
 970         .sign_packet    = gensec_gssapi_sign_packet,
 971         .check_packet   = gensec_gssapi_check_packet,
 972         .seal_packet    = gensec_gssapi_seal_packet,
 973         .unseal_packet  = gensec_gssapi_unseal_packet,
 974         .wrap           = gensec_gssapi_wrap,
 975         .unwrap         = gensec_gssapi_unwrap,
 976         .have_feature   = gensec_gssapi_have_feature,
 977         .enabled        = True
 978 };
 979
 980 NTSTATUS gensec_gssapi_init(void)
 981 {
 982         NTSTATUS ret;
 983
 984         ret = gensec_register(&gensec_gssapi_krb5_security_ops);
 985         if (!NT_STATUS_IS_OK(ret)) {
 986                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 987                         gensec_gssapi_krb5_security_ops.name));
 988                 return ret;
 989         }
 990
 991         return ret;
 992 }