source4/auth/gensec/gensec_gssapi.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Kerberos backend for GENSEC
   5
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
   7    Copyright (C) Stefan Metzmacher <metze@samba.org> 2004-2005
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23 */
  24
  25 #include "includes.h"
  26 #include "system/kerberos.h"
  27 #include "system/network.h"
  28 #include "auth/kerberos/kerberos.h"
  29 #include "librpc/gen_ndr/ndr_krb5pac.h"
  30 #include "auth/auth.h"
  31
  32 struct gensec_gssapi_state {
  33         gss_ctx_id_t gssapi_context;
  34         struct gss_channel_bindings_struct *input_chan_bindings;
  35         gss_name_t server_name;
  36         gss_name_t client_name;
  37         OM_uint32 want_flags, got_flags;
  38         const gss_OID_desc *gss_oid;
  39
  40         DATA_BLOB session_key;
  41         DATA_BLOB pac;
  42
  43         struct smb_krb5_context *smb_krb5_context;
  44         krb5_ccache ccache;
  45         const char *ccache_name;
  46         krb5_keytab keytab;
  47
  48         gss_cred_id_t cred;
  49 };
  50
  51 static char *gssapi_error_string(TALLOC_CTX *mem_ctx,
  52                                  OM_uint32 maj_stat, OM_uint32 min_stat)
  53 {
  54         OM_uint32 disp_min_stat, disp_maj_stat;
  55         gss_buffer_desc maj_error_message;
  56         gss_buffer_desc min_error_message;
  57         OM_uint32 msg_ctx = 0;
  58
  59         char *ret;
  60
  61         maj_error_message.value = NULL;
  62         min_error_message.value = NULL;
  63
  64         disp_maj_stat = gss_display_status(&disp_min_stat, maj_stat, GSS_C_GSS_CODE,
  65                            GSS_C_NULL_OID, &msg_ctx, &maj_error_message);
  66         disp_maj_stat = gss_display_status(&disp_min_stat, min_stat, GSS_C_MECH_CODE,
  67                            GSS_C_NULL_OID, &msg_ctx, &min_error_message);
  68         ret = talloc_asprintf(mem_ctx, "%s: %s", (char *)maj_error_message.value, (char *)min_error_message.value);
  69
  70         gss_release_buffer(&disp_min_stat, &maj_error_message);
  71         gss_release_buffer(&disp_min_stat, &min_error_message);
  72
  73         return ret;
  74 }
  75
  76
  77 static int gensec_gssapi_destory(void *ptr)
  78 {
  79         struct gensec_gssapi_state *gensec_gssapi_state = ptr;
  80         OM_uint32 maj_stat, min_stat;
  81
  82         if (gensec_gssapi_state->cred != GSS_C_NO_CREDENTIAL) {
  83                 maj_stat = gss_release_cred(&min_stat,
  84                                             &gensec_gssapi_state->cred);
  85         }
  86
  87         if (gensec_gssapi_state->gssapi_context != GSS_C_NO_CONTEXT) {
  88                 maj_stat = gss_delete_sec_context (&min_stat,
  89                                                    &gensec_gssapi_state->gssapi_context,
  90                                                    GSS_C_NO_BUFFER);
  91         }
  92
  93         if (gensec_gssapi_state->server_name != GSS_C_NO_NAME) {
  94                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->server_name);
  95         }
  96         if (gensec_gssapi_state->client_name != GSS_C_NO_NAME) {
  97                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->client_name);
  98         }
  99         return 0;
 100 }
 101
 102 static NTSTATUS gensec_gssapi_start(struct gensec_security *gensec_security)
 103 {
 104         struct gensec_gssapi_state *gensec_gssapi_state;
 105         krb5_error_code ret;
 106
 107         gensec_gssapi_state = talloc(gensec_security, struct gensec_gssapi_state);
 108         if (!gensec_gssapi_state) {
 109                 return NT_STATUS_NO_MEMORY;
 110         }
 111
 112         gensec_security->private_data = gensec_gssapi_state;
 113
 114         gensec_gssapi_state->gssapi_context = GSS_C_NO_CONTEXT;
 115         gensec_gssapi_state->server_name = GSS_C_NO_NAME;
 116         gensec_gssapi_state->client_name = GSS_C_NO_NAME;
 117
 118         /* TODO: Fill in channel bindings */
 119         gensec_gssapi_state->input_chan_bindings = GSS_C_NO_CHANNEL_BINDINGS;
 120
 121         gensec_gssapi_state->want_flags = GSS_C_MUTUAL_FLAG;
 122         gensec_gssapi_state->got_flags = 0;
 123
 124         gensec_gssapi_state->session_key = data_blob(NULL, 0);
 125         gensec_gssapi_state->pac = data_blob(NULL, 0);
 126
 127         gensec_gssapi_state->cred = GSS_C_NO_CREDENTIAL;
 128
 129         talloc_set_destructor(gensec_gssapi_state, gensec_gssapi_destory);
 130
 131         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 132                 gensec_gssapi_state->want_flags |= GSS_C_INTEG_FLAG;
 133         }
 134         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 135                 gensec_gssapi_state->want_flags |= GSS_C_CONF_FLAG;
 136         }
 137         if (gensec_security->want_features & GENSEC_FEATURE_DCE_STYLE) {
 138                 gensec_gssapi_state->want_flags |= GSS_C_DCE_STYLE;
 139         }
 140
 141         gensec_gssapi_state->gss_oid = gss_mech_krb5;
 142
 143         ret = smb_krb5_init_context(gensec_gssapi_state,
 144                                     &gensec_gssapi_state->smb_krb5_context);
 145         if (ret) {
 146                 DEBUG(1,("gensec_krb5_start: krb5_init_context failed (%s)\n",
 147                          error_message(ret)));
 148                 return NT_STATUS_INTERNAL_ERROR;
 149         }
 150         return NT_STATUS_OK;
 151 }
 152
 153 static NTSTATUS gensec_gssapi_server_start(struct gensec_security *gensec_security)
 154 {
 155         NTSTATUS nt_status;
 156         OM_uint32 maj_stat, min_stat;
 157         gss_buffer_desc name_token;
 158         struct gensec_gssapi_state *gensec_gssapi_state;
 159         struct cli_credentials *machine_account;
 160
 161         nt_status = gensec_gssapi_start(gensec_security);
 162         if (!NT_STATUS_IS_OK(nt_status)) {
 163                 return nt_status;
 164         }
 165
 166         gensec_gssapi_state = gensec_security->private_data;
 167
 168         machine_account = cli_credentials_init(gensec_gssapi_state);
 169         cli_credentials_set_conf(machine_account);
 170         nt_status = cli_credentials_set_machine_account(machine_account);
 171
 172         if (!NT_STATUS_IS_OK(nt_status)) {
 173                 DEBUG(3, ("Could not obtain machine account credentials from the local database\n"));
 174                 talloc_free(machine_account);
 175                 return nt_status;
 176         } else {
 177                 nt_status = create_memory_keytab(gensec_gssapi_state,
 178                                                  machine_account,
 179                                                  gensec_gssapi_state->smb_krb5_context,
 180                                                  &gensec_gssapi_state->keytab);
 181                 if (!NT_STATUS_IS_OK(nt_status)) {
 182                         DEBUG(3, ("Could not create memory keytab!\n"));
 183                         talloc_free(machine_account);
 184                         return nt_status;
 185                 }
 186         }
 187
 188         name_token.value = cli_credentials_get_principal(machine_account,
 189                                                          machine_account);
 190         name_token.length = strlen(name_token.value);
 191
 192         maj_stat = gss_import_name (&min_stat,
 193                                     &name_token,
 194                                     GSS_C_NT_USER_NAME,
 195                                     &gensec_gssapi_state->server_name);
 196         talloc_free(machine_account);
 197
 198         if (maj_stat) {
 199                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 200                           (char *)name_token.value,
 201                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 202                 return NT_STATUS_UNSUCCESSFUL;
 203         }
 204
 205         maj_stat = gsskrb5_acquire_cred(&min_stat,
 206                                         gensec_gssapi_state->keytab, NULL,
 207                                         gensec_gssapi_state->server_name,
 208                                         GSS_C_INDEFINITE,
 209                                         GSS_C_NULL_OID_SET,
 210                                         GSS_C_ACCEPT,
 211                                         &gensec_gssapi_state->cred,
 212                                         NULL,
 213                                         NULL);
 214         if (maj_stat) {
 215                 DEBUG(1, ("Aquiring acceptor credentails failed: %s\n",
 216                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 217                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 218         }
 219
 220         return NT_STATUS_OK;
 221
 222 }
 223
 224 static NTSTATUS gensec_gssapi_client_start(struct gensec_security *gensec_security)
 225 {
 226         struct gensec_gssapi_state *gensec_gssapi_state;
 227         struct cli_credentials *creds = gensec_get_credentials(gensec_security);
 228         struct ccache_container *ccache;
 229         krb5_error_code ret;
 230         NTSTATUS nt_status;
 231         gss_buffer_desc name_token;
 232         gss_OID name_type;
 233         OM_uint32 maj_stat, min_stat;
 234         const char *hostname = gensec_get_target_hostname(gensec_security);
 235         const char *principal;
 236
 237         if (!hostname) {
 238                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 239                 return NT_STATUS_INVALID_PARAMETER;
 240         }
 241         if (is_ipaddress(hostname)) {
 242                 DEBUG(2, ("Cannot do GSSAPI to an IP address\n"));
 243                 return NT_STATUS_INVALID_PARAMETER;
 244         }
 245         if (strequal(hostname, "localhost")) {
 246                 DEBUG(2, ("GSSAPI to 'localhost' does not make sense\n"));
 247                 return NT_STATUS_INVALID_PARAMETER;
 248         }
 249
 250         nt_status = gensec_gssapi_start(gensec_security);
 251         if (!NT_STATUS_IS_OK(nt_status)) {
 252                 return nt_status;
 253         }
 254
 255         gensec_gssapi_state = gensec_security->private_data;
 256
 257         ret = cli_credentials_get_ccache(creds,
 258                                          &ccache);
 259         if (ret) {
 260                 DEBUG(1, ("Failed to get CCACHE for gensec_gssapi: %s\n", error_message(ret)));
 261                 return NT_STATUS_UNSUCCESSFUL;
 262         }
 263
 264         name_token.value = cli_credentials_get_principal(creds,
 265                                                          gensec_gssapi_state);
 266         name_token.length = strlen(name_token.value);
 267
 268         maj_stat = gss_import_name (&min_stat,
 269                                     &name_token,
 270                                     GSS_C_NT_USER_NAME,
 271                                     &gensec_gssapi_state->client_name);
 272         if (maj_stat) {
 273                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 274                           (char *)name_token.value,
 275                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 276                 return NT_STATUS_INVALID_PARAMETER;
 277         }
 278
 279         principal = gensec_get_target_principal(gensec_security);
 280         if (principal && lp_client_use_spnego_principal()) {
 281                 name_token.value = gensec_get_target_principal(gensec_security);
 282                 name_token.length = strlen(name_token.value);
 283                 name_type = GSS_C_NULL_OID;
 284         } else {
 285                 name_token.value = talloc_asprintf(gensec_gssapi_state, "%s@%s",
 286                                                    gensec_get_target_service(gensec_security),
 287                                                    hostname);
 288                 name_token.length = strlen(name_token.value);
 289                 name_type = GSS_C_NT_HOSTBASED_SERVICE;
 290         }
 291
 292         maj_stat = gss_import_name (&min_stat,
 293                                     &name_token,
 294                                     name_type,
 295                                     &gensec_gssapi_state->server_name);
 296         if (maj_stat) {
 297                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 298                           (char *)name_token.value,
 299                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 300                 return NT_STATUS_INVALID_PARAMETER;
 301         }
 302
 303         maj_stat = gsskrb5_acquire_cred(&min_stat,
 304                                         NULL, ccache->ccache,
 305                                         gensec_gssapi_state->client_name,
 306                                         GSS_C_INDEFINITE,
 307                                         GSS_C_NULL_OID_SET,
 308                                         GSS_C_INITIATE,
 309                                         &gensec_gssapi_state->cred,
 310                                         NULL,
 311                                         NULL);
 312         if (maj_stat) {
 313                 switch (min_stat) {
 314                 case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 315                         DEBUG(3, ("Server [%s] is not registered with our KDC: %s\n",
 316                                   hostname, gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 317                         return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 318                 default:
 319                         DEBUG(1, ("Aquiring initiator credentails failed: %s\n",
 320                                   gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 321                         return NT_STATUS_UNSUCCESSFUL;
 322                 }
 323         }
 324
 325         return NT_STATUS_OK;
 326 }
 327
 328
 329 /**
 330  * Check if the packet is one for this mechansim
 331  *
 332  * @param gensec_security GENSEC state
 333  * @param in The request, as a DATA_BLOB
 334  * @return Error, INVALID_PARAMETER if it's not a packet for us
 335  *                or NT_STATUS_OK if the packet is ok.
 336  */
 337
 338 static NTSTATUS gensec_gssapi_magic(struct gensec_security *gensec_security,
 339                                     const DATA_BLOB *in)
 340 {
 341         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 342                 return NT_STATUS_OK;
 343         } else {
 344                 return NT_STATUS_INVALID_PARAMETER;
 345         }
 346 }
 347
 348
 349 /**
 350  * Next state function for the GSSAPI GENSEC mechanism
 351  *
 352  * @param gensec_gssapi_state GSSAPI State
 353  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 354  * @param in The request, as a DATA_BLOB
 355  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 356  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 357  *                or NT_STATUS_OK if the user is authenticated.
 358  */
 359
 360 static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 361                                    TALLOC_CTX *out_mem_ctx,
 362                                    const DATA_BLOB in, DATA_BLOB *out)
 363 {
 364         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 365         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 366         OM_uint32 maj_stat, min_stat;
 367         OM_uint32 min_stat2;
 368         gss_buffer_desc input_token, output_token;
 369         gss_OID gss_oid_p;
 370         input_token.length = in.length;
 371         input_token.value = in.data;
 372
 373         switch (gensec_security->gensec_role) {
 374         case GENSEC_CLIENT:
 375         {
 376                 maj_stat = gss_init_sec_context(&min_stat,
 377                                                 gensec_gssapi_state->cred,
 378                                                 &gensec_gssapi_state->gssapi_context,
 379                                                 gensec_gssapi_state->server_name,
 380                                                 discard_const_p(gss_OID_desc, gensec_gssapi_state->gss_oid),
 381                                                 gensec_gssapi_state->want_flags,
 382                                                 0,
 383                                                 gensec_gssapi_state->input_chan_bindings,
 384                                                 &input_token,
 385                                                 NULL,
 386                                                 &output_token,
 387                                                 &gensec_gssapi_state->got_flags, /* ret flags */
 388                                                 NULL);
 389                 break;
 390         }
 391         case GENSEC_SERVER:
 392         {
 393                 maj_stat = gss_accept_sec_context(&min_stat,
 394                                                   &gensec_gssapi_state->gssapi_context,
 395                                                   gensec_gssapi_state->cred,
 396                                                   &input_token,
 397                                                   gensec_gssapi_state->input_chan_bindings,
 398                                                   &gensec_gssapi_state->client_name,
 399                                                   &gss_oid_p,
 400                                                   &output_token,
 401                                                   &gensec_gssapi_state->got_flags,
 402                                                   NULL,
 403                                                   NULL);
 404                 gensec_gssapi_state->gss_oid = gss_oid_p;
 405                 break;
 406         }
 407         default:
 408                 return NT_STATUS_INVALID_PARAMETER;
 409
 410         }
 411
 412         if (maj_stat == GSS_S_COMPLETE) {
 413                 *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 414                 gss_release_buffer(&min_stat2, &output_token);
 415
 416                 return NT_STATUS_OK;
 417         } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 418                 *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 419                 gss_release_buffer(&min_stat2, &output_token);
 420
 421                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 422         } else if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 423             && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 424                        gensec_gssapi_state->gss_oid->length) == 0)) {
 425                 switch (min_stat) {
 426                 case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 427                         DEBUG(3, ("Server is not registered with our KDC: %s\n",
 428                                   gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 429                         return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 430                 case KRB5KRB_AP_ERR_MSG_TYPE:
 431                         /* garbage input, possibly from the auto-mech detection */
 432                         return NT_STATUS_INVALID_PARAMETER;
 433                 default:
 434                         DEBUG(1, ("GSS(krb5) Update failed: %s\n",
 435                                   gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 436                         return nt_status;
 437                 }
 438         } else {
 439                 DEBUG(1, ("GSS Update failed: %s\n",
 440                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 441                 return nt_status;
 442         }
 443 }
 444
 445 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 446                                    TALLOC_CTX *mem_ctx,
 447                                    const DATA_BLOB *in,
 448                                    DATA_BLOB *out)
 449 {
 450         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 451         OM_uint32 maj_stat, min_stat;
 452         gss_buffer_desc input_token, output_token;
 453         int conf_state;
 454         input_token.length = in->length;
 455         input_token.value = in->data;
 456
 457         maj_stat = gss_wrap(&min_stat,
 458                             gensec_gssapi_state->gssapi_context,
 459                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 460                             GSS_C_QOP_DEFAULT,
 461                             &input_token,
 462                             &conf_state,
 463                             &output_token);
 464         if (GSS_ERROR(maj_stat)) {
 465                 DEBUG(1, ("gensec_gssapi_wrap: GSS Wrap failed: %s\n",
 466                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 467                 return NT_STATUS_ACCESS_DENIED;
 468         }
 469
 470         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 471         gss_release_buffer(&min_stat, &output_token);
 472
 473         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 474             && !conf_state) {
 475                 return NT_STATUS_ACCESS_DENIED;
 476         }
 477         return NT_STATUS_OK;
 478 }
 479
 480 static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 481                                      TALLOC_CTX *mem_ctx,
 482                                      const DATA_BLOB *in,
 483                                      DATA_BLOB *out)
 484 {
 485         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 486         OM_uint32 maj_stat, min_stat;
 487         gss_buffer_desc input_token, output_token;
 488         int conf_state;
 489         gss_qop_t qop_state;
 490         input_token.length = in->length;
 491         input_token.value = in->data;
 492
 493         maj_stat = gss_unwrap(&min_stat,
 494                               gensec_gssapi_state->gssapi_context,
 495                               &input_token,
 496                               &output_token,
 497                               &conf_state,
 498                               &qop_state);
 499         if (GSS_ERROR(maj_stat)) {
 500                 DEBUG(1, ("gensec_gssapi_unwrap: GSS UnWrap failed: %s\n",
 501                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 502                 return NT_STATUS_ACCESS_DENIED;
 503         }
 504
 505         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 506         gss_release_buffer(&min_stat, &output_token);
 507
 508         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 509             && !conf_state) {
 510                 return NT_STATUS_ACCESS_DENIED;
 511         }
 512         return NT_STATUS_OK;
 513 }
 514
 515 static size_t gensec_gssapi_sig_size(struct gensec_security *gensec_security, size_t data_size)
 516 {
 517         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 518         OM_uint32 maj_stat, min_stat;
 519         OM_uint32 output_size;
 520         if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
 521             || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 522                        gensec_gssapi_state->gss_oid->length) != 0)) {
 523                 DEBUG(1, ("NO sig size available for this mech\n"));
 524                 return 0;
 525         }
 526
 527         maj_stat = gsskrb5_wrap_size(&min_stat,
 528                                      gensec_gssapi_state->gssapi_context,
 529                                      gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 530                                      GSS_C_QOP_DEFAULT,
 531                                      data_size,
 532                                      &output_size);
 533         if (GSS_ERROR(maj_stat)) {
 534                 TALLOC_CTX *mem_ctx = talloc_new(NULL);
 535                 DEBUG(1, ("gensec_gssapi_seal_packet: determinaing signature size with gss_wrap_size_limit failed: %s\n",
 536                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 537                 talloc_free(mem_ctx);
 538                 return 0;
 539         }
 540
 541         if (output_size < data_size) {
 542                 return 0;
 543         }
 544
 545         /* The difference between the max output and the max input must be the signature */
 546         return output_size - data_size;
 547 }
 548
 549 static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_security,
 550                                           TALLOC_CTX *mem_ctx,
 551                                           uint8_t *data, size_t length,
 552                                           const uint8_t *whole_pdu, size_t pdu_length,
 553                                           DATA_BLOB *sig)
 554 {
 555         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 556         OM_uint32 maj_stat, min_stat;
 557         gss_buffer_desc input_token, output_token;
 558         int conf_state;
 559         ssize_t sig_length;
 560
 561         input_token.length = length;
 562         input_token.value = data;
 563
 564         maj_stat = gss_wrap(&min_stat,
 565                             gensec_gssapi_state->gssapi_context,
 566                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 567                             GSS_C_QOP_DEFAULT,
 568                             &input_token,
 569                             &conf_state,
 570                             &output_token);
 571         if (GSS_ERROR(maj_stat)) {
 572                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap failed: %s\n",
 573                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 574                 return NT_STATUS_ACCESS_DENIED;
 575         }
 576
 577         sig_length = gensec_gssapi_sig_size(gensec_security, length);
 578
 579         /* Caller must pad to right boundary */
 580         if (output_token.length != (length + sig_length)) {
 581                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap length [%d] does not match caller length [%d] plus sig size [%d] = [%d]\n",
 582                           output_token.length, length, sig_length, length + sig_length));
 583                 return NT_STATUS_INTERNAL_ERROR;
 584         }
 585
 586         memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);
 587         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 588
 589         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 590         dump_data_pw("gensec_gssapi_seal_packet: clear\n", data, length);
 591         dump_data_pw("gensec_gssapi_seal_packet: sealed\n", ((uint8_t *)output_token.value) + sig_length, output_token.length - sig_length);
 592
 593         gss_release_buffer(&min_stat, &output_token);
 594
 595         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 596             && !conf_state) {
 597                 return NT_STATUS_ACCESS_DENIED;
 598         }
 599         return NT_STATUS_OK;
 600 }
 601
 602 static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_security,
 603                                             TALLOC_CTX *mem_ctx,
 604                                             uint8_t *data, size_t length,
 605                                             const uint8_t *whole_pdu, size_t pdu_length,
 606                                             const DATA_BLOB *sig)
 607 {
 608         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 609         OM_uint32 maj_stat, min_stat;
 610         gss_buffer_desc input_token, output_token;
 611         int conf_state;
 612         gss_qop_t qop_state;
 613         DATA_BLOB in;
 614
 615         dump_data_pw("gensec_gssapi_unseal_packet: sig\n", sig->data, sig->length);
 616
 617         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 618
 619         memcpy(in.data, sig->data, sig->length);
 620         memcpy(in.data + sig->length, data, length);
 621
 622         input_token.length = in.length;
 623         input_token.value = in.data;
 624
 625         maj_stat = gss_unwrap(&min_stat,
 626                               gensec_gssapi_state->gssapi_context,
 627                               &input_token,
 628                               &output_token,
 629                               &conf_state,
 630                               &qop_state);
 631         if (GSS_ERROR(maj_stat)) {
 632                 DEBUG(1, ("gensec_gssapi_unseal_packet: GSS UnWrap failed: %s\n",
 633                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 634                 return NT_STATUS_ACCESS_DENIED;
 635         }
 636
 637         if (output_token.length != length) {
 638                 return NT_STATUS_INTERNAL_ERROR;
 639         }
 640
 641         memcpy(data, output_token.value, length);
 642
 643         gss_release_buffer(&min_stat, &output_token);
 644
 645         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 646             && !conf_state) {
 647                 return NT_STATUS_ACCESS_DENIED;
 648         }
 649         return NT_STATUS_OK;
 650 }
 651
 652 static NTSTATUS gensec_gssapi_sign_packet(struct gensec_security *gensec_security,
 653                                           TALLOC_CTX *mem_ctx,
 654                                           const uint8_t *data, size_t length,
 655                                           const uint8_t *whole_pdu, size_t pdu_length,
 656                                           DATA_BLOB *sig)
 657 {
 658         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 659         OM_uint32 maj_stat, min_stat;
 660         gss_buffer_desc input_token, output_token;
 661         int conf_state;
 662         ssize_t sig_length = 0;
 663
 664         input_token.length = length;
 665         input_token.value = discard_const_p(uint8_t *, data);
 666
 667         maj_stat = gss_wrap(&min_stat,
 668                             gensec_gssapi_state->gssapi_context,
 669                             0,
 670                             GSS_C_QOP_DEFAULT,
 671                             &input_token,
 672                             &conf_state,
 673                             &output_token);
 674         if (GSS_ERROR(maj_stat)) {
 675                 DEBUG(1, ("GSS Wrap failed: %s\n",
 676                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 677                 return NT_STATUS_ACCESS_DENIED;
 678         }
 679
 680         if (output_token.length < length) {
 681                 return NT_STATUS_INTERNAL_ERROR;
 682         }
 683
 684         sig_length = gensec_gssapi_sig_size(gensec_security, length);
 685
 686         /* Caller must pad to right boundary */
 687         if (output_token.length != (length + sig_length)) {
 688                 DEBUG(1, ("gensec_gssapi_sign_packet: GSS Wrap length [%d] does not match caller length [%d] plus sig size [%d] = [%d]\n",
 689                           output_token.length, length, sig_length, length + sig_length));
 690                 return NT_STATUS_INTERNAL_ERROR;
 691         }
 692
 693         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 694
 695         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 696
 697         gss_release_buffer(&min_stat, &output_token);
 698
 699         return NT_STATUS_OK;
 700 }
 701
 702 static NTSTATUS gensec_gssapi_check_packet(struct gensec_security *gensec_security,
 703                                            TALLOC_CTX *mem_ctx,
 704                                            const uint8_t *data, size_t length,
 705                                            const uint8_t *whole_pdu, size_t pdu_length,
 706                                            const DATA_BLOB *sig)
 707 {
 708         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 709         OM_uint32 maj_stat, min_stat;
 710         gss_buffer_desc input_token, output_token;
 711         int conf_state;
 712         gss_qop_t qop_state;
 713         DATA_BLOB in;
 714
 715         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 716
 717         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 718
 719         memcpy(in.data, sig->data, sig->length);
 720         memcpy(in.data + sig->length, data, length);
 721
 722         input_token.length = in.length;
 723         input_token.value = in.data;
 724
 725         maj_stat = gss_unwrap(&min_stat,
 726                               gensec_gssapi_state->gssapi_context,
 727                               &input_token,
 728                               &output_token,
 729                               &conf_state,
 730                               &qop_state);
 731         if (GSS_ERROR(maj_stat)) {
 732                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 733                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 734                 return NT_STATUS_ACCESS_DENIED;
 735         }
 736
 737         if (output_token.length != length) {
 738                 return NT_STATUS_INTERNAL_ERROR;
 739         }
 740
 741         gss_release_buffer(&min_stat, &output_token);
 742
 743         return NT_STATUS_OK;
 744 }
 745
 746 static BOOL gensec_gssapi_have_feature(struct gensec_security *gensec_security,
 747                                        uint32_t feature)
 748 {
 749         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 750         if (feature & GENSEC_FEATURE_SIGN) {
 751                 return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
 752         }
 753         if (feature & GENSEC_FEATURE_SEAL) {
 754                 return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
 755         }
 756         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 757                 if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 758                     && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements, gensec_gssapi_state->gss_oid->length) == 0)) {
 759                         return True;
 760                 }
 761         }
 762         if (feature & GENSEC_FEATURE_DCE_STYLE) {
 763                 return gensec_gssapi_state->got_flags & GSS_C_DCE_STYLE;
 764         }
 765         if (feature & GENSEC_FEATURE_ASYNC_REPLIES) {
 766                 return True;
 767         }
 768         return False;
 769 }
 770
 771 static NTSTATUS gensec_gssapi_session_key(struct gensec_security *gensec_security,
 772                                           DATA_BLOB *session_key)
 773 {
 774         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 775
 776         if (gensec_gssapi_state->session_key.data) {
 777                 *session_key = gensec_gssapi_state->session_key;
 778                 return NT_STATUS_OK;
 779         }
 780
 781         /* Ensure we only call this for GSSAPI/krb5, otherwise things could get very ugly */
 782         if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 783             && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 784                        gensec_gssapi_state->gss_oid->length) == 0)) {
 785                 OM_uint32 maj_stat, min_stat;
 786                 gss_buffer_desc skey;
 787
 788                 maj_stat = gsskrb5_get_initiator_subkey(&min_stat,
 789                                                         gensec_gssapi_state->gssapi_context,
 790                                                         &skey);
 791
 792                 if (maj_stat == 0) {
 793                         DEBUG(10, ("Got KRB5 session key of length %d\n",
 794                                    (int)skey.length));
 795                         gensec_gssapi_state->session_key = data_blob_talloc(gensec_gssapi_state,
 796                                                                             skey.value, skey.length);
 797                         *session_key = gensec_gssapi_state->session_key;
 798                         dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 799
 800                         gss_release_buffer(&min_stat, &skey);
 801                         return NT_STATUS_OK;
 802                 }
 803                 return NT_STATUS_NO_USER_SESSION_KEY;
 804         }
 805
 806         DEBUG(1, ("NO session key for this mech\n"));
 807         return NT_STATUS_NO_USER_SESSION_KEY;
 808 }
 809
 810 static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_security,
 811                                          struct auth_session_info **_session_info)
 812 {
 813         NTSTATUS nt_status;
 814         TALLOC_CTX *mem_ctx;
 815         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 816         struct auth_serversupplied_info *server_info = NULL;
 817         struct auth_session_info *session_info = NULL;
 818         struct PAC_LOGON_INFO *logon_info;
 819         OM_uint32 maj_stat, min_stat;
 820         gss_buffer_desc name_token;
 821         gss_buffer_desc pac;
 822         krb5_keyblock *keyblock;
 823         time_t authtime;
 824         krb5_principal principal;
 825         char *principal_string;
 826
 827         if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
 828             || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 829                        gensec_gssapi_state->gss_oid->length) != 0)) {
 830                 DEBUG(1, ("NO session info available for this mech\n"));
 831                 return NT_STATUS_INVALID_PARAMETER;
 832         }
 833
 834         mem_ctx = talloc_named(gensec_gssapi_state, 0, "gensec_gssapi_session_info context");
 835         NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
 836
 837         maj_stat = gss_display_name (&min_stat,
 838                                      gensec_gssapi_state->client_name,
 839                                      &name_token,
 840                                      NULL);
 841         if (maj_stat) {
 842                 return NT_STATUS_FOOBAR;
 843         }
 844
 845         principal_string = talloc_strndup(mem_ctx, name_token.value, name_token.length);
 846
 847         gss_release_buffer(&min_stat, &name_token);
 848
 849         if (!principal_string) {
 850                 talloc_free(mem_ctx);
 851                 return NT_STATUS_NO_MEMORY;
 852         }
 853
 854         maj_stat = gss_krb5_copy_service_keyblock(&min_stat,
 855                                                   gensec_gssapi_state->gssapi_context,
 856                                                   &keyblock);
 857
 858         if (maj_stat == 0) {
 859                 maj_stat = gsskrb5_extract_authtime_from_sec_context(&min_stat,
 860                                                                      gensec_gssapi_state->gssapi_context,
 861                                                                      &authtime);
 862         }
 863
 864         if (maj_stat == 0) {
 865                 maj_stat = gsskrb5_extract_authz_data_from_sec_context(&min_stat,
 866                                                                        gensec_gssapi_state->gssapi_context,
 867                                                                        KRB5_AUTHDATA_IF_RELEVANT,
 868                                                                        &pac);
 869         }
 870
 871         if (maj_stat == 0) {
 872                 krb5_error_code ret;
 873                 DATA_BLOB pac_blob = data_blob_talloc(mem_ctx, pac.value, pac.length);
 874                 pac_blob = unwrap_pac(mem_ctx, &pac_blob);
 875                 gss_release_buffer(&min_stat, &pac);
 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                 krb5_error_code ret;
 908                 DATA_BLOB user_sess_key = data_blob(NULL, 0);
 909                 DATA_BLOB lm_sess_key = data_blob(NULL, 0);
 910                 /* IF we have the PAC - otherwise we need to get this
 911                  * data from elsewere - local ldb, or (TODO) lookup of some
 912                  * kind...
 913                  *
 914                  * when heimdal can generate the PAC, we should fail if there's
 915                  * no PAC present
 916                  */
 917
 918                 char *account_name;
 919                 const char *realm;
 920                 ret = krb5_parse_name(gensec_gssapi_state->smb_krb5_context->krb5_context,
 921                                       principal_string, &principal);
 922                 if (ret) {
 923                         talloc_free(mem_ctx);
 924                         return NT_STATUS_INVALID_PARAMETER;
 925                 }
 926
 927                 realm = krb5_principal_get_realm(gensec_gssapi_state->smb_krb5_context->krb5_context,
 928                                                  principal);
 929                 ret = krb5_unparse_name_norealm(gensec_gssapi_state->smb_krb5_context->krb5_context,
 930                                                 principal, &account_name);
 931                 if (ret) {
 932                         krb5_free_principal(gensec_gssapi_state->smb_krb5_context->krb5_context, principal);
 933                         talloc_free(mem_ctx);
 934                         return NT_STATUS_NO_MEMORY;
 935                 }
 936
 937                 DEBUG(1, ("Unable to use PAC, resorting to local user lookup!\n"));
 938                 nt_status = sam_get_server_info(mem_ctx, account_name, realm,
 939                                                 user_sess_key, lm_sess_key,
 940                                                 &server_info);
 941                 free(account_name);
 942                 krb5_free_principal(gensec_gssapi_state->smb_krb5_context->krb5_context, principal);
 943
 944                 if (!NT_STATUS_IS_OK(nt_status)) {
 945                         talloc_free(mem_ctx);
 946                         return nt_status;
 947                 }
 948         }
 949
 950         /* references the server_info into the session_info */
 951         nt_status = auth_generate_session_info(gensec_gssapi_state, server_info, &session_info);
 952         talloc_free(mem_ctx);
 953         talloc_free(server_info);
 954         NT_STATUS_NOT_OK_RETURN(nt_status);
 955
 956         nt_status = gensec_gssapi_session_key(gensec_security, &session_info->session_key);
 957         NT_STATUS_NOT_OK_RETURN(nt_status);
 958
 959         *_session_info = session_info;
 960
 961         return NT_STATUS_OK;
 962 }
 963
 964 static const char *gensec_gssapi_krb5_oids[] = {
 965         GENSEC_OID_KERBEROS5,
 966         GENSEC_OID_KERBEROS5_OLD,
 967         NULL
 968 };
 969
 970 /* As a server, this could in theory accept any GSSAPI mech */
 971 static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
 972         .name           = "gssapi_krb5",
 973         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 974         .oid            = gensec_gssapi_krb5_oids,
 975         .client_start   = gensec_gssapi_client_start,
 976         .server_start   = gensec_gssapi_server_start,
 977         .magic          = gensec_gssapi_magic,
 978         .update         = gensec_gssapi_update,
 979         .session_key    = gensec_gssapi_session_key,
 980         .session_info   = gensec_gssapi_session_info,
 981         .sig_size       = gensec_gssapi_sig_size,
 982         .sign_packet    = gensec_gssapi_sign_packet,
 983         .check_packet   = gensec_gssapi_check_packet,
 984         .seal_packet    = gensec_gssapi_seal_packet,
 985         .unseal_packet  = gensec_gssapi_unseal_packet,
 986         .wrap           = gensec_gssapi_wrap,
 987         .unwrap         = gensec_gssapi_unwrap,
 988         .have_feature   = gensec_gssapi_have_feature,
 989         .enabled        = True
 990 };
 991
 992 NTSTATUS gensec_gssapi_init(void)
 993 {
 994         NTSTATUS ret;
 995
 996         ret = gensec_register(&gensec_gssapi_krb5_security_ops);
 997         if (!NT_STATUS_IS_OK(ret)) {
 998                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 999                         gensec_gssapi_krb5_security_ops.name));
1000                 return ret;
1001         }
1002
1003         return ret;
1004 }