source/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 "heimdal/lib/gssapi/gssapi/gssapi.h"
  28 #include "auth/kerberos/kerberos.h"
  29 #include "librpc/gen_ndr/krb5pac.h"
  30 #include "auth/auth.h"
  31 #include "lib/ldb/include/ldb.h"
  32 #include "auth/auth_sam.h"
  33 #include "librpc/rpc/dcerpc.h"
  34 #include "auth/credentials/credentials.h"
  35 #include "auth/credentials/credentials_krb5.h"
  36 #include "auth/gensec/gensec.h"
  37
  38 enum gensec_gssapi_sasl_state
  39 {
  40         STAGE_GSS_NEG,
  41         STAGE_SASL_SSF_NEG,
  42         STAGE_SASL_SSF_ACCEPT,
  43         STAGE_DONE
  44 };
  45
  46 #define NEG_SEAL 0x4
  47 #define NEG_SIGN 0x2
  48 #define NEG_NONE 0x1
  49
  50 struct gensec_gssapi_state {
  51         gss_ctx_id_t gssapi_context;
  52         struct gss_channel_bindings_struct *input_chan_bindings;
  53         gss_name_t server_name;
  54         gss_name_t client_name;
  55         OM_uint32 want_flags, got_flags;
  56         const gss_OID_desc *gss_oid;
  57
  58         DATA_BLOB session_key;
  59         DATA_BLOB pac;
  60
  61         struct smb_krb5_context *smb_krb5_context;
  62         struct gssapi_creds_container *client_cred;
  63         struct gssapi_creds_container *server_cred;
  64
  65         gss_cred_id_t delegated_cred_handle;
  66
  67         BOOL sasl; /* We have two different mechs in this file: One
  68                     * for SASL wrapped GSSAPI and another for normal
  69                     * GSSAPI */
  70         enum gensec_gssapi_sasl_state sasl_state;
  71         uint8_t sasl_protection; /* What was negotiated at the SASL
  72                                   * layer, independent of the GSSAPI
  73                                   * layer... */
  74
  75         size_t max_wrap_buf_size;
  76         int gss_exchange_count;
  77 };
  78
  79 static size_t gensec_gssapi_max_input_size(struct gensec_security *gensec_security);
  80 static size_t gensec_gssapi_max_wrapped_size(struct gensec_security *gensec_security);
  81
  82 static char *gssapi_error_string(TALLOC_CTX *mem_ctx,
  83                                  OM_uint32 maj_stat, OM_uint32 min_stat,
  84                                  const gss_OID_desc *mech)
  85 {
  86         OM_uint32 disp_min_stat, disp_maj_stat;
  87         gss_buffer_desc maj_error_message;
  88         gss_buffer_desc min_error_message;
  89         OM_uint32 msg_ctx = 0;
  90
  91         char *ret;
  92
  93         maj_error_message.value = NULL;
  94         min_error_message.value = NULL;
  95
  96         disp_maj_stat = gss_display_status(&disp_min_stat, maj_stat, GSS_C_GSS_CODE,
  97                            mech, &msg_ctx, &maj_error_message);
  98         disp_maj_stat = gss_display_status(&disp_min_stat, min_stat, GSS_C_MECH_CODE,
  99                            mech, &msg_ctx, &min_error_message);
 100         ret = talloc_asprintf(mem_ctx, "%s: %s", (char *)maj_error_message.value, (char *)min_error_message.value);
 101
 102         gss_release_buffer(&disp_min_stat, &maj_error_message);
 103         gss_release_buffer(&disp_min_stat, &min_error_message);
 104
 105         return ret;
 106 }
 107
 108
 109 static int gensec_gssapi_destory(struct gensec_gssapi_state *gensec_gssapi_state)
 110 {
 111         OM_uint32 maj_stat, min_stat;
 112
 113         if (gensec_gssapi_state->delegated_cred_handle != GSS_C_NO_CREDENTIAL) {
 114                 maj_stat = gss_release_cred(&min_stat,
 115                                             &gensec_gssapi_state->delegated_cred_handle);
 116         }
 117
 118         if (gensec_gssapi_state->gssapi_context != GSS_C_NO_CONTEXT) {
 119                 maj_stat = gss_delete_sec_context (&min_stat,
 120                                                    &gensec_gssapi_state->gssapi_context,
 121                                                    GSS_C_NO_BUFFER);
 122         }
 123
 124         if (gensec_gssapi_state->server_name != GSS_C_NO_NAME) {
 125                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->server_name);
 126         }
 127         if (gensec_gssapi_state->client_name != GSS_C_NO_NAME) {
 128                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->client_name);
 129         }
 130         return 0;
 131 }
 132
 133 static NTSTATUS gensec_gssapi_start(struct gensec_security *gensec_security)
 134 {
 135         struct gensec_gssapi_state *gensec_gssapi_state;
 136         krb5_error_code ret;
 137         struct gsskrb5_send_to_kdc send_to_kdc;
 138
 139         gensec_gssapi_state = talloc(gensec_security, struct gensec_gssapi_state);
 140         if (!gensec_gssapi_state) {
 141                 return NT_STATUS_NO_MEMORY;
 142         }
 143
 144         gensec_gssapi_state->gss_exchange_count = 0;
 145         gensec_gssapi_state->max_wrap_buf_size
 146                 = lp_parm_int(-1, "gensec_gssapi", "max wrap buf size", 65536);
 147
 148         gensec_gssapi_state->sasl = False;
 149         gensec_gssapi_state->sasl_state = STAGE_GSS_NEG;
 150
 151         gensec_security->private_data = gensec_gssapi_state;
 152
 153         gensec_gssapi_state->gssapi_context = GSS_C_NO_CONTEXT;
 154         gensec_gssapi_state->server_name = GSS_C_NO_NAME;
 155         gensec_gssapi_state->client_name = GSS_C_NO_NAME;
 156
 157         /* TODO: Fill in channel bindings */
 158         gensec_gssapi_state->input_chan_bindings = GSS_C_NO_CHANNEL_BINDINGS;
 159
 160         gensec_gssapi_state->want_flags = 0;
 161         if (lp_parm_bool(-1, "gensec_gssapi", "mutual", True)) {
 162                 gensec_gssapi_state->want_flags |= GSS_C_MUTUAL_FLAG;
 163         }
 164         if (lp_parm_bool(-1, "gensec_gssapi", "delegation", True)) {
 165                 gensec_gssapi_state->want_flags |= GSS_C_DELEG_FLAG;
 166         }
 167         if (lp_parm_bool(-1, "gensec_gssapi", "replay", True)) {
 168                 gensec_gssapi_state->want_flags |= GSS_C_REPLAY_FLAG;
 169         }
 170         if (lp_parm_bool(-1, "gensec_gssapi", "sequence", True)) {
 171                 gensec_gssapi_state->want_flags |= GSS_C_SEQUENCE_FLAG;
 172         }
 173
 174         gensec_gssapi_state->got_flags = 0;
 175
 176         gensec_gssapi_state->session_key = data_blob(NULL, 0);
 177         gensec_gssapi_state->pac = data_blob(NULL, 0);
 178
 179         gensec_gssapi_state->delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 180
 181         talloc_set_destructor(gensec_gssapi_state, gensec_gssapi_destory);
 182
 183         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 184                 gensec_gssapi_state->want_flags |= GSS_C_INTEG_FLAG;
 185         }
 186         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 187                 gensec_gssapi_state->want_flags |= GSS_C_CONF_FLAG;
 188         }
 189         if (gensec_security->want_features & GENSEC_FEATURE_DCE_STYLE) {
 190                 gensec_gssapi_state->want_flags |= GSS_C_DCE_STYLE;
 191         }
 192
 193         gensec_gssapi_state->gss_oid = gss_mech_krb5;
 194
 195         send_to_kdc.func = smb_krb5_send_and_recv_func;
 196         send_to_kdc.ptr = gensec_security->event_ctx;
 197
 198         ret = gsskrb5_set_send_to_kdc(&send_to_kdc);
 199         if (ret) {
 200                 DEBUG(1,("gensec_krb5_start: gsskrb5_set_send_to_kdc failed\n"));
 201                 talloc_free(gensec_gssapi_state);
 202                 return NT_STATUS_INTERNAL_ERROR;
 203         }
 204         if (lp_realm() && *lp_realm()) {
 205                 char *upper_realm = strupper_talloc(gensec_gssapi_state, lp_realm());
 206                 if (!upper_realm) {
 207                         DEBUG(1,("gensec_krb5_start: could not uppercase realm: %s\n", lp_realm()));
 208                         talloc_free(gensec_gssapi_state);
 209                         return NT_STATUS_NO_MEMORY;
 210                 }
 211                 ret = gsskrb5_set_default_realm(upper_realm);
 212                 talloc_free(upper_realm);
 213                 if (ret) {
 214                         DEBUG(1,("gensec_krb5_start: gsskrb5_set_default_realm failed\n"));
 215                         talloc_free(gensec_gssapi_state);
 216                         return NT_STATUS_INTERNAL_ERROR;
 217                 }
 218         }
 219
 220         ret = smb_krb5_init_context(gensec_gssapi_state,
 221                                     &gensec_gssapi_state->smb_krb5_context);
 222         if (ret) {
 223                 DEBUG(1,("gensec_krb5_start: krb5_init_context failed (%s)\n",
 224                          error_message(ret)));
 225                 talloc_free(gensec_gssapi_state);
 226                 return NT_STATUS_INTERNAL_ERROR;
 227         }
 228         return NT_STATUS_OK;
 229 }
 230
 231 static NTSTATUS gensec_gssapi_server_start(struct gensec_security *gensec_security)
 232 {
 233         NTSTATUS nt_status;
 234         int ret;
 235         struct gensec_gssapi_state *gensec_gssapi_state;
 236         struct cli_credentials *machine_account;
 237         struct gssapi_creds_container *gcc;
 238
 239         nt_status = gensec_gssapi_start(gensec_security);
 240         if (!NT_STATUS_IS_OK(nt_status)) {
 241                 return nt_status;
 242         }
 243
 244         gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 245
 246         machine_account = gensec_get_credentials(gensec_security);
 247
 248         if (!machine_account) {
 249                 DEBUG(3, ("No machine account credentials specified\n"));
 250                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 251         } else {
 252                 ret = cli_credentials_get_server_gss_creds(machine_account, &gcc);
 253                 if (ret) {
 254                         DEBUG(1, ("Aquiring acceptor credentials failed: %s\n",
 255                                   error_message(ret)));
 256                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 257                 }
 258         }
 259
 260         gensec_gssapi_state->server_cred = gcc;
 261         return NT_STATUS_OK;
 262
 263 }
 264
 265 static NTSTATUS gensec_gssapi_sasl_server_start(struct gensec_security *gensec_security)
 266 {
 267         NTSTATUS nt_status;
 268         struct gensec_gssapi_state *gensec_gssapi_state;
 269         nt_status = gensec_gssapi_server_start(gensec_security);
 270
 271         if (NT_STATUS_IS_OK(nt_status)) {
 272                 gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 273                 gensec_gssapi_state->sasl = True;
 274         }
 275         return nt_status;
 276 }
 277
 278 static NTSTATUS gensec_gssapi_client_start(struct gensec_security *gensec_security)
 279 {
 280         struct gensec_gssapi_state *gensec_gssapi_state;
 281         struct cli_credentials *creds = gensec_get_credentials(gensec_security);
 282         krb5_error_code ret;
 283         NTSTATUS nt_status;
 284         gss_buffer_desc name_token;
 285         gss_OID name_type;
 286         OM_uint32 maj_stat, min_stat;
 287         const char *hostname = gensec_get_target_hostname(gensec_security);
 288         const char *principal;
 289         struct gssapi_creds_container *gcc;
 290
 291         if (!hostname) {
 292                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 293                 return NT_STATUS_INVALID_PARAMETER;
 294         }
 295         if (is_ipaddress(hostname)) {
 296                 DEBUG(2, ("Cannot do GSSAPI to an IP address\n"));
 297                 return NT_STATUS_INVALID_PARAMETER;
 298         }
 299         if (strcmp(hostname, "localhost") == 0) {
 300                 DEBUG(2, ("GSSAPI to 'localhost' does not make sense\n"));
 301                 return NT_STATUS_INVALID_PARAMETER;
 302         }
 303
 304         nt_status = gensec_gssapi_start(gensec_security);
 305         if (!NT_STATUS_IS_OK(nt_status)) {
 306                 return nt_status;
 307         }
 308
 309         gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 310
 311         principal = gensec_get_target_principal(gensec_security);
 312         if (principal && lp_client_use_spnego_principal()) {
 313                 name_token.value  = discard_const_p(uint8_t, principal);
 314                 name_token.length = strlen(principal);
 315
 316                 name_type = GSS_C_NULL_OID;
 317         } else {
 318                 principal = talloc_asprintf(gensec_gssapi_state, "%s@%s",
 319                                             gensec_get_target_service(gensec_security),
 320                                             hostname);
 321
 322                 name_token.value  = discard_const_p(uint8_t, principal);
 323                 name_token.length = strlen(principal);
 324
 325                 name_type = GSS_C_NT_HOSTBASED_SERVICE;
 326         }
 327
 328         maj_stat = gss_import_name (&min_stat,
 329                                     &name_token,
 330                                     name_type,
 331                                     &gensec_gssapi_state->server_name);
 332         if (maj_stat) {
 333                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 334                           (char *)name_token.value,
 335                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 336                 return NT_STATUS_INVALID_PARAMETER;
 337         }
 338
 339         ret = cli_credentials_get_client_gss_creds(creds, &gcc);
 340         switch (ret) {
 341         case 0:
 342                 break;
 343         case KRB5_KDC_UNREACH:
 344                 DEBUG(3, ("Cannot reach a KDC we require\n"));
 345                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 346         default:
 347                 DEBUG(1, ("Aquiring initiator credentails failed\n"));
 348                 return NT_STATUS_UNSUCCESSFUL;
 349         }
 350
 351         gensec_gssapi_state->client_cred = gcc;
 352
 353         return NT_STATUS_OK;
 354 }
 355
 356 static NTSTATUS gensec_gssapi_sasl_client_start(struct gensec_security *gensec_security)
 357 {
 358         NTSTATUS nt_status;
 359         struct gensec_gssapi_state *gensec_gssapi_state;
 360         nt_status = gensec_gssapi_client_start(gensec_security);
 361
 362         if (NT_STATUS_IS_OK(nt_status)) {
 363                 gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 364                 gensec_gssapi_state->sasl = True;
 365         }
 366         return nt_status;
 367 }
 368
 369
 370 /**
 371  * Check if the packet is one for this mechansim
 372  *
 373  * @param gensec_security GENSEC state
 374  * @param in The request, as a DATA_BLOB
 375  * @return Error, INVALID_PARAMETER if it's not a packet for us
 376  *                or NT_STATUS_OK if the packet is ok.
 377  */
 378
 379 static NTSTATUS gensec_gssapi_magic(struct gensec_security *gensec_security,
 380                                     const DATA_BLOB *in)
 381 {
 382         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 383                 return NT_STATUS_OK;
 384         } else {
 385                 return NT_STATUS_INVALID_PARAMETER;
 386         }
 387 }
 388
 389
 390 /**
 391  * Next state function for the GSSAPI GENSEC mechanism
 392  *
 393  * @param gensec_gssapi_state GSSAPI State
 394  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 395  * @param in The request, as a DATA_BLOB
 396  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 397  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 398  *                or NT_STATUS_OK if the user is authenticated.
 399  */
 400
 401 static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 402                                    TALLOC_CTX *out_mem_ctx,
 403                                    const DATA_BLOB in, DATA_BLOB *out)
 404 {
 405         struct gensec_gssapi_state *gensec_gssapi_state
 406                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 407         NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
 408         OM_uint32 maj_stat, min_stat;
 409         OM_uint32 min_stat2;
 410         gss_buffer_desc input_token, output_token;
 411         gss_OID gss_oid_p;
 412         input_token.length = in.length;
 413         input_token.value = in.data;
 414
 415         switch (gensec_gssapi_state->sasl_state) {
 416         case STAGE_GSS_NEG:
 417         {
 418                 switch (gensec_security->gensec_role) {
 419                 case GENSEC_CLIENT:
 420                 {
 421                         maj_stat = gss_init_sec_context(&min_stat,
 422                                                         gensec_gssapi_state->client_cred->creds,
 423                                                         &gensec_gssapi_state->gssapi_context,
 424                                                         gensec_gssapi_state->server_name,
 425                                                         discard_const_p(gss_OID_desc, gensec_gssapi_state->gss_oid),
 426                                                         gensec_gssapi_state->want_flags,
 427                                                         0,
 428                                                         gensec_gssapi_state->input_chan_bindings,
 429                                                         &input_token,
 430                                                         NULL,
 431                                                         &output_token,
 432                                                         &gensec_gssapi_state->got_flags, /* ret flags */
 433                                                         NULL);
 434                         break;
 435                 }
 436                 case GENSEC_SERVER:
 437                 {
 438                         maj_stat = gss_accept_sec_context(&min_stat,
 439                                                           &gensec_gssapi_state->gssapi_context,
 440                                                           gensec_gssapi_state->server_cred->creds,
 441                                                           &input_token,
 442                                                           gensec_gssapi_state->input_chan_bindings,
 443                                                           &gensec_gssapi_state->client_name,
 444                                                           &gss_oid_p,
 445                                                           &output_token,
 446                                                           &gensec_gssapi_state->got_flags,
 447                                                           NULL,
 448                                                           &gensec_gssapi_state->delegated_cred_handle);
 449                         gensec_gssapi_state->gss_oid = gss_oid_p;
 450                         break;
 451                 }
 452                 default:
 453                         return NT_STATUS_INVALID_PARAMETER;
 454
 455                 }
 456
 457                 gensec_gssapi_state->gss_exchange_count++;
 458
 459                 if (maj_stat == GSS_S_COMPLETE) {
 460                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 461                         gss_release_buffer(&min_stat2, &output_token);
 462
 463                         if (gensec_gssapi_state->got_flags & GSS_C_DELEG_FLAG) {
 464                                 DEBUG(5, ("gensec_gssapi: credentials were delegated\n"));
 465                         } else {
 466                                 DEBUG(5, ("gensec_gssapi: NO credentials were delegated\n"));
 467                         }
 468
 469                         /* We may have been invoked as SASL, so there
 470                          * is more work to do */
 471                         if (gensec_gssapi_state->sasl) {
 472                                 /* Due to a very subtle interaction
 473                                  * with SASL and the LDAP libs, we
 474                                  * must ensure the data pointer is
 475                                  * != NULL, but the length is 0.
 476                                  *
 477                                  * This ensures we send a 'zero
 478                                  * length' (rather than NULL) response
 479                                  */
 480
 481                                 if (!out->data) {
 482                                         out->data = (uint8_t *)talloc_strdup(out_mem_ctx, "\0");
 483                                 }
 484
 485                                 gensec_gssapi_state->sasl_state = STAGE_SASL_SSF_NEG;
 486                                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 487                         } else {
 488                                 gensec_gssapi_state->sasl_state = STAGE_DONE;
 489
 490                                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 491                                         DEBUG(5, ("GSSAPI Connection will be cryptographicly sealed\n"));
 492                                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 493                                         DEBUG(5, ("GSSAPI Connection will be cryptographicly signed\n"));
 494                                 } else {
 495                                         DEBUG(5, ("GSSAPI Connection will have no cryptographic protection\n"));
 496                                 }
 497
 498                                 return NT_STATUS_OK;
 499                         }
 500                 } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 501                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 502                         gss_release_buffer(&min_stat2, &output_token);
 503
 504                         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 505                 } else if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 506                            && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 507                                       gensec_gssapi_state->gss_oid->length) == 0)) {
 508                         switch (min_stat) {
 509                         case KRB5_KDC_UNREACH:
 510                                 DEBUG(3, ("Cannot reach a KDC we require: %s\n",
 511                                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 512                                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 513                         case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 514                                 DEBUG(3, ("Server is not registered with our KDC: %s\n",
 515                                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 516                                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 517                         case KRB5KRB_AP_ERR_MSG_TYPE:
 518                                 /* garbage input, possibly from the auto-mech detection */
 519                                 return NT_STATUS_INVALID_PARAMETER;
 520                         default:
 521                                 DEBUG(1, ("GSS Update(krb5)(%d) Update failed: %s\n",
 522                                           gensec_gssapi_state->gss_exchange_count,
 523                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 524                                 return nt_status;
 525                         }
 526                 } else {
 527                         DEBUG(1, ("GSS Update(%d) failed: %s\n",
 528                                   gensec_gssapi_state->gss_exchange_count,
 529                                   gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 530                         return nt_status;
 531                 }
 532                 break;
 533         }
 534
 535         /* These last two stages are only done if we were invoked as SASL */
 536         case STAGE_SASL_SSF_NEG:
 537         {
 538                 switch (gensec_security->gensec_role) {
 539                 case GENSEC_CLIENT:
 540                 {
 541                         uint8_t maxlength_proposed[4];
 542                         uint8_t maxlength_accepted[4];
 543                         uint8_t security_supported;
 544                         int conf_state;
 545                         gss_qop_t qop_state;
 546                         input_token.length = in.length;
 547                         input_token.value = in.data;
 548
 549                         /* As a client, we have just send a
 550                          * zero-length blob to the server (after the
 551                          * normal GSSAPI exchange), and it has replied
 552                          * with it's SASL negotiation */
 553
 554                         maj_stat = gss_unwrap(&min_stat,
 555                                               gensec_gssapi_state->gssapi_context,
 556                                               &input_token,
 557                                               &output_token,
 558                                               &conf_state,
 559                                               &qop_state);
 560                         if (GSS_ERROR(maj_stat)) {
 561                                 DEBUG(1, ("gensec_gssapi_update: GSS UnWrap of SASL protection negotiation failed: %s\n",
 562                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 563                                 return NT_STATUS_ACCESS_DENIED;
 564                         }
 565
 566                         if (output_token.length < 4) {
 567                                 return NT_STATUS_INVALID_PARAMETER;
 568                         }
 569
 570                         memcpy(maxlength_proposed, output_token.value, 4);
 571                         gss_release_buffer(&min_stat, &output_token);
 572
 573                         /* first byte is the proposed security */
 574                         security_supported = maxlength_proposed[0];
 575                         maxlength_proposed[0] = '\0';
 576
 577                         /* Rest is the proposed max wrap length */
 578                         gensec_gssapi_state->max_wrap_buf_size = MIN(RIVAL(maxlength_proposed, 0),
 579                                                                      gensec_gssapi_state->max_wrap_buf_size);
 580                         gensec_gssapi_state->sasl_protection = 0;
 581                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 582                                 if (security_supported & NEG_SEAL) {
 583                                         gensec_gssapi_state->sasl_protection |= NEG_SEAL;
 584                                 }
 585                         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 586                                 if (security_supported & NEG_SIGN) {
 587                                         gensec_gssapi_state->sasl_protection |= NEG_SIGN;
 588                                 }
 589                         } else if (security_supported & NEG_NONE) {
 590                                 gensec_gssapi_state->sasl_protection |= NEG_NONE;
 591                         } else {
 592                                 DEBUG(1, ("Remote server does not support unprotected connections"));
 593                                 return NT_STATUS_ACCESS_DENIED;
 594                         }
 595
 596                         /* Send back the negotiated max length */
 597
 598                         RSIVAL(maxlength_accepted, 0, gensec_gssapi_state->max_wrap_buf_size);
 599
 600                         maxlength_accepted[0] = gensec_gssapi_state->sasl_protection;
 601
 602                         input_token.value = maxlength_accepted;
 603                         input_token.length = sizeof(maxlength_accepted);
 604
 605                         maj_stat = gss_wrap(&min_stat,
 606                                             gensec_gssapi_state->gssapi_context,
 607                                             False,
 608                                             GSS_C_QOP_DEFAULT,
 609                                             &input_token,
 610                                             &conf_state,
 611                                             &output_token);
 612                         if (GSS_ERROR(maj_stat)) {
 613                                 DEBUG(1, ("GSS Update(SSF_NEG): GSS Wrap failed: %s\n",
 614                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 615                                 return NT_STATUS_ACCESS_DENIED;
 616                         }
 617
 618                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 619                         gss_release_buffer(&min_stat, &output_token);
 620
 621                         /* quirk:  This changes the value that gensec_have_feature returns, to be that after SASL negotiation */
 622                         gensec_gssapi_state->sasl_state = STAGE_DONE;
 623
 624                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 625                                 DEBUG(3, ("SASL/GSSAPI Connection to server will be cryptographicly sealed\n"));
 626                         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 627                                 DEBUG(3, ("SASL/GSSAPI Connection to server will be cryptographicly signed\n"));
 628                         } else {
 629                                 DEBUG(3, ("SASL/GSSAPI Connection to server will have no cryptographicly protection\n"));
 630                         }
 631
 632                         return NT_STATUS_OK;
 633                 }
 634                 case GENSEC_SERVER:
 635                 {
 636                         uint8_t maxlength_proposed[4];
 637                         uint8_t security_supported = 0x0;
 638                         int conf_state;
 639
 640                         /* As a server, we have just been sent a zero-length blob (note this, but it isn't fatal) */
 641                         if (in.length != 0) {
 642                                 DEBUG(1, ("SASL/GSSAPI: client sent non-zero length starting SASL negotiation!\n"));
 643                         }
 644
 645                         /* Give the client some idea what we will support */
 646
 647                         RSIVAL(maxlength_proposed, 0, gensec_gssapi_state->max_wrap_buf_size);
 648                         /* first byte is the proposed security */
 649                         maxlength_proposed[0] = '\0';
 650
 651                         gensec_gssapi_state->sasl_protection = 0;
 652                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 653                                 security_supported |= NEG_SEAL;
 654                         }
 655                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 656                                 security_supported |= NEG_SIGN;
 657                         }
 658                         if (security_supported == 0) {
 659                                 /* If we don't support anything, this must be 0 */
 660                                 RSIVAL(maxlength_proposed, 0, 0x0);
 661                         }
 662
 663                         /* TODO:  We may not wish to support this */
 664                         security_supported |= NEG_NONE;
 665                         maxlength_proposed[0] = security_supported;
 666
 667                         input_token.value = maxlength_proposed;
 668                         input_token.length = sizeof(maxlength_proposed);
 669
 670                         maj_stat = gss_wrap(&min_stat,
 671                                             gensec_gssapi_state->gssapi_context,
 672                                             False,
 673                                             GSS_C_QOP_DEFAULT,
 674                                             &input_token,
 675                                             &conf_state,
 676                                             &output_token);
 677                         if (GSS_ERROR(maj_stat)) {
 678                                 DEBUG(1, ("GSS Update(SSF_NEG): GSS Wrap failed: %s\n",
 679                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 680                                 return NT_STATUS_ACCESS_DENIED;
 681                         }
 682
 683                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 684                         gss_release_buffer(&min_stat, &output_token);
 685
 686                         gensec_gssapi_state->sasl_state = STAGE_SASL_SSF_ACCEPT;
 687                         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 688                 }
 689                 default:
 690                         return NT_STATUS_INVALID_PARAMETER;
 691
 692                 }
 693         }
 694         /* This is s server-only stage */
 695         case STAGE_SASL_SSF_ACCEPT:
 696         {
 697                 uint8_t maxlength_accepted[4];
 698                 uint8_t security_accepted;
 699                 int conf_state;
 700                 gss_qop_t qop_state;
 701                 input_token.length = in.length;
 702                 input_token.value = in.data;
 703
 704                 maj_stat = gss_unwrap(&min_stat,
 705                                       gensec_gssapi_state->gssapi_context,
 706                                       &input_token,
 707                                       &output_token,
 708                                       &conf_state,
 709                                       &qop_state);
 710                 if (GSS_ERROR(maj_stat)) {
 711                         DEBUG(1, ("gensec_gssapi_update: GSS UnWrap of SASL protection negotiation failed: %s\n",
 712                                   gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 713                         return NT_STATUS_ACCESS_DENIED;
 714                 }
 715
 716                 if (output_token.length < 4) {
 717                         return NT_STATUS_INVALID_PARAMETER;
 718                 }
 719
 720                 memcpy(maxlength_accepted, output_token.value, 4);
 721                 gss_release_buffer(&min_stat, &output_token);
 722
 723                 /* first byte is the proposed security */
 724                 security_accepted = maxlength_accepted[0];
 725                 maxlength_accepted[0] = '\0';
 726
 727                 /* Rest is the proposed max wrap length */
 728                 gensec_gssapi_state->max_wrap_buf_size = MIN(RIVAL(maxlength_accepted, 0),
 729                                                              gensec_gssapi_state->max_wrap_buf_size);
 730
 731                 gensec_gssapi_state->sasl_protection = 0;
 732                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 733                         if (security_accepted & NEG_SEAL) {
 734                                 gensec_gssapi_state->sasl_protection |= NEG_SEAL;
 735                         }
 736                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 737                         if (security_accepted & NEG_SIGN) {
 738                                 gensec_gssapi_state->sasl_protection |= NEG_SIGN;
 739                         }
 740                 } else if (security_accepted & NEG_NONE) {
 741                         gensec_gssapi_state->sasl_protection |= NEG_NONE;
 742                 } else {
 743                         DEBUG(1, ("Remote client does not support unprotected connections, but we failed to negotiate anything better"));
 744                         return NT_STATUS_ACCESS_DENIED;
 745                 }
 746
 747                 /* quirk:  This changes the value that gensec_have_feature returns, to be that after SASL negotiation */
 748                 gensec_gssapi_state->sasl_state = STAGE_DONE;
 749                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 750                         DEBUG(5, ("SASL/GSSAPI Connection from client will be cryptographicly sealed\n"));
 751                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 752                         DEBUG(5, ("SASL/GSSAPI Connection from client will be cryptographicly signed\n"));
 753                 } else {
 754                         DEBUG(5, ("SASL/GSSAPI Connection from client will have no cryptographic protection\n"));
 755                 }
 756
 757                 *out = data_blob(NULL, 0);
 758                 return NT_STATUS_OK;
 759         }
 760         default:
 761                 return NT_STATUS_INVALID_PARAMETER;
 762         }
 763 }
 764
 765 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 766                                    TALLOC_CTX *mem_ctx,
 767                                    const DATA_BLOB *in,
 768                                    DATA_BLOB *out)
 769 {
 770         struct gensec_gssapi_state *gensec_gssapi_state
 771                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 772         OM_uint32 maj_stat, min_stat;
 773         gss_buffer_desc input_token, output_token;
 774         int conf_state;
 775         input_token.length = in->length;
 776         input_token.value = in->data;
 777
 778         maj_stat = gss_wrap(&min_stat,
 779                             gensec_gssapi_state->gssapi_context,
 780                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 781                             GSS_C_QOP_DEFAULT,
 782                             &input_token,
 783                             &conf_state,
 784                             &output_token);
 785         if (GSS_ERROR(maj_stat)) {
 786                 DEBUG(1, ("gensec_gssapi_wrap: GSS Wrap failed: %s\n",
 787                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 788                 return NT_STATUS_ACCESS_DENIED;
 789         }
 790
 791         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 792         gss_release_buffer(&min_stat, &output_token);
 793
 794         if (gensec_gssapi_state->sasl) {
 795                 size_t max_wrapped_size = gensec_gssapi_max_wrapped_size(gensec_security);
 796                 if (max_wrapped_size < out->length) {
 797                         DEBUG(1, ("gensec_gssapi_wrap: when wrapped, INPUT data (%u) is grew to be larger than SASL negotiated maximum output size (%u > %u)\n",
 798                                   (unsigned)in->length,
 799                                   (unsigned)out->length,
 800                                   (unsigned int)max_wrapped_size));
 801                         return NT_STATUS_INVALID_PARAMETER;
 802                 }
 803         }
 804
 805         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 806             && !conf_state) {
 807                 return NT_STATUS_ACCESS_DENIED;
 808         }
 809         return NT_STATUS_OK;
 810 }
 811
 812 static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 813                                      TALLOC_CTX *mem_ctx,
 814                                      const DATA_BLOB *in,
 815                                      DATA_BLOB *out)
 816 {
 817         struct gensec_gssapi_state *gensec_gssapi_state
 818                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 819         OM_uint32 maj_stat, min_stat;
 820         gss_buffer_desc input_token, output_token;
 821         int conf_state;
 822         gss_qop_t qop_state;
 823         input_token.length = in->length;
 824         input_token.value = in->data;
 825
 826         if (gensec_gssapi_state->sasl) {
 827                 size_t max_wrapped_size = gensec_gssapi_max_wrapped_size(gensec_security);
 828                 if (max_wrapped_size < in->length) {
 829                         DEBUG(1, ("gensec_gssapi_unwrap: WRAPPED data is larger than SASL negotiated maximum size\n"));
 830                         return NT_STATUS_INVALID_PARAMETER;
 831                 }
 832         }
 833
 834         maj_stat = gss_unwrap(&min_stat,
 835                               gensec_gssapi_state->gssapi_context,
 836                               &input_token,
 837                               &output_token,
 838                               &conf_state,
 839                               &qop_state);
 840         if (GSS_ERROR(maj_stat)) {
 841                 DEBUG(1, ("gensec_gssapi_unwrap: GSS UnWrap failed: %s\n",
 842                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 843                 return NT_STATUS_ACCESS_DENIED;
 844         }
 845
 846         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 847         gss_release_buffer(&min_stat, &output_token);
 848
 849         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 850             && !conf_state) {
 851                 return NT_STATUS_ACCESS_DENIED;
 852         }
 853         return NT_STATUS_OK;
 854 }
 855
 856 /* Find out the maximum input size negotiated on this connection */
 857
 858 static size_t gensec_gssapi_max_input_size(struct gensec_security *gensec_security)
 859 {
 860         struct gensec_gssapi_state *gensec_gssapi_state
 861                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 862         OM_uint32 maj_stat, min_stat;
 863         OM_uint32 max_input_size;
 864
 865         maj_stat = gss_wrap_size_limit(&min_stat,
 866                                        gensec_gssapi_state->gssapi_context,
 867                                        gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 868                                        GSS_C_QOP_DEFAULT,
 869                                        gensec_gssapi_state->max_wrap_buf_size,
 870                                        &max_input_size);
 871         if (GSS_ERROR(maj_stat)) {
 872                 TALLOC_CTX *mem_ctx = talloc_new(NULL);
 873                 DEBUG(1, ("gensec_gssapi_max_input_size: determinaing signature size with gss_wrap_size_limit failed: %s\n",
 874                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 875                 talloc_free(mem_ctx);
 876                 return 0;
 877         }
 878
 879         return max_input_size;
 880 }
 881
 882 /* Find out the maximum output size negotiated on this connection */
 883 static size_t gensec_gssapi_max_wrapped_size(struct gensec_security *gensec_security)
 884 {
 885         struct gensec_gssapi_state *gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);;
 886         return gensec_gssapi_state->max_wrap_buf_size;
 887 }
 888
 889 static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_security,
 890                                           TALLOC_CTX *mem_ctx,
 891                                           uint8_t *data, size_t length,
 892                                           const uint8_t *whole_pdu, size_t pdu_length,
 893                                           DATA_BLOB *sig)
 894 {
 895         struct gensec_gssapi_state *gensec_gssapi_state
 896                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 897         OM_uint32 maj_stat, min_stat;
 898         gss_buffer_desc input_token, output_token;
 899         int conf_state;
 900         ssize_t sig_length;
 901
 902         input_token.length = length;
 903         input_token.value = data;
 904
 905         maj_stat = gss_wrap(&min_stat,
 906                             gensec_gssapi_state->gssapi_context,
 907                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 908                             GSS_C_QOP_DEFAULT,
 909                             &input_token,
 910                             &conf_state,
 911                             &output_token);
 912         if (GSS_ERROR(maj_stat)) {
 913                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap failed: %s\n",
 914                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 915                 return NT_STATUS_ACCESS_DENIED;
 916         }
 917
 918         if (output_token.length < input_token.length) {
 919                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap length [%ld] *less* than caller length [%ld]\n",
 920                           (long)output_token.length, (long)length));
 921                 return NT_STATUS_INTERNAL_ERROR;
 922         }
 923         sig_length = output_token.length - input_token.length;
 924
 925         memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);
 926         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 927
 928         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 929         dump_data_pw("gensec_gssapi_seal_packet: clear\n", data, length);
 930         dump_data_pw("gensec_gssapi_seal_packet: sealed\n", ((uint8_t *)output_token.value) + sig_length, output_token.length - sig_length);
 931
 932         gss_release_buffer(&min_stat, &output_token);
 933
 934         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 935             && !conf_state) {
 936                 return NT_STATUS_ACCESS_DENIED;
 937         }
 938         return NT_STATUS_OK;
 939 }
 940
 941 static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_security,
 942                                             TALLOC_CTX *mem_ctx,
 943                                             uint8_t *data, size_t length,
 944                                             const uint8_t *whole_pdu, size_t pdu_length,
 945                                             const DATA_BLOB *sig)
 946 {
 947         struct gensec_gssapi_state *gensec_gssapi_state
 948                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 949         OM_uint32 maj_stat, min_stat;
 950         gss_buffer_desc input_token, output_token;
 951         int conf_state;
 952         gss_qop_t qop_state;
 953         DATA_BLOB in;
 954
 955         dump_data_pw("gensec_gssapi_unseal_packet: sig\n", sig->data, sig->length);
 956
 957         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 958
 959         memcpy(in.data, sig->data, sig->length);
 960         memcpy(in.data + sig->length, data, length);
 961
 962         input_token.length = in.length;
 963         input_token.value = in.data;
 964
 965         maj_stat = gss_unwrap(&min_stat,
 966                               gensec_gssapi_state->gssapi_context,
 967                               &input_token,
 968                               &output_token,
 969                               &conf_state,
 970                               &qop_state);
 971         if (GSS_ERROR(maj_stat)) {
 972                 DEBUG(1, ("gensec_gssapi_unseal_packet: GSS UnWrap failed: %s\n",
 973                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 974                 return NT_STATUS_ACCESS_DENIED;
 975         }
 976
 977         if (output_token.length != length) {
 978                 return NT_STATUS_INTERNAL_ERROR;
 979         }
 980
 981         memcpy(data, output_token.value, length);
 982
 983         gss_release_buffer(&min_stat, &output_token);
 984
 985         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 986             && !conf_state) {
 987                 return NT_STATUS_ACCESS_DENIED;
 988         }
 989         return NT_STATUS_OK;
 990 }
 991
 992 static NTSTATUS gensec_gssapi_sign_packet(struct gensec_security *gensec_security,
 993                                           TALLOC_CTX *mem_ctx,
 994                                           const uint8_t *data, size_t length,
 995                                           const uint8_t *whole_pdu, size_t pdu_length,
 996                                           DATA_BLOB *sig)
 997 {
 998         struct gensec_gssapi_state *gensec_gssapi_state
 999                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1000         OM_uint32 maj_stat, min_stat;
1001         gss_buffer_desc input_token, output_token;
1002         int conf_state;
1003         ssize_t sig_length = 0;
1004
1005         input_token.length = length;
1006         input_token.value = discard_const_p(uint8_t *, data);
1007
1008         maj_stat = gss_wrap(&min_stat,
1009                             gensec_gssapi_state->gssapi_context,
1010                             0,
1011                             GSS_C_QOP_DEFAULT,
1012                             &input_token,
1013                             &conf_state,
1014                             &output_token);
1015         if (GSS_ERROR(maj_stat)) {
1016                 DEBUG(1, ("GSS Wrap failed: %s\n",
1017                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1018                 return NT_STATUS_ACCESS_DENIED;
1019         }
1020
1021         if (output_token.length < input_token.length) {
1022                 DEBUG(1, ("gensec_gssapi_sign_packet: GSS Wrap length [%ld] *less* than caller length [%ld]\n",
1023                           (long)output_token.length, (long)length));
1024                 return NT_STATUS_INTERNAL_ERROR;
1025         }
1026
1027         /* Caller must pad to right boundary */
1028         sig_length = output_token.length - input_token.length;
1029
1030         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
1031
1032         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
1033
1034         gss_release_buffer(&min_stat, &output_token);
1035
1036         return NT_STATUS_OK;
1037 }
1038
1039 static NTSTATUS gensec_gssapi_check_packet(struct gensec_security *gensec_security,
1040                                            TALLOC_CTX *mem_ctx,
1041                                            const uint8_t *data, size_t length,
1042                                            const uint8_t *whole_pdu, size_t pdu_length,
1043                                            const DATA_BLOB *sig)
1044 {
1045         struct gensec_gssapi_state *gensec_gssapi_state
1046                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1047         OM_uint32 maj_stat, min_stat;
1048         gss_buffer_desc input_token, output_token;
1049         int conf_state;
1050         gss_qop_t qop_state;
1051         DATA_BLOB in;
1052
1053         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
1054
1055         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
1056
1057         memcpy(in.data, sig->data, sig->length);
1058         memcpy(in.data + sig->length, data, length);
1059
1060         input_token.length = in.length;
1061         input_token.value = in.data;
1062
1063         maj_stat = gss_unwrap(&min_stat,
1064                               gensec_gssapi_state->gssapi_context,
1065                               &input_token,
1066                               &output_token,
1067                               &conf_state,
1068                               &qop_state);
1069         if (GSS_ERROR(maj_stat)) {
1070                 DEBUG(1, ("GSS UnWrap failed: %s\n",
1071                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1072                 return NT_STATUS_ACCESS_DENIED;
1073         }
1074
1075         if (output_token.length != length) {
1076                 return NT_STATUS_INTERNAL_ERROR;
1077         }
1078
1079         gss_release_buffer(&min_stat, &output_token);
1080
1081         return NT_STATUS_OK;
1082 }
1083
1084 /* Try to figure out what features we actually got on the connection */
1085 static BOOL gensec_gssapi_have_feature(struct gensec_security *gensec_security,
1086                                        uint32_t feature)
1087 {
1088         struct gensec_gssapi_state *gensec_gssapi_state
1089                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1090         if (feature & GENSEC_FEATURE_SIGN) {
1091                 /* If we are going GSSAPI SASL, then we honour the second negotiation */
1092                 if (gensec_gssapi_state->sasl
1093                     && gensec_gssapi_state->sasl_state == STAGE_DONE) {
1094                         return ((gensec_gssapi_state->sasl_protection & NEG_SIGN)
1095                                 && (gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG));
1096                 }
1097                 return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
1098         }
1099         if (feature & GENSEC_FEATURE_SEAL) {
1100                 /* If we are going GSSAPI SASL, then we honour the second negotiation */
1101                 if (gensec_gssapi_state->sasl
1102                     && gensec_gssapi_state->sasl_state == STAGE_DONE) {
1103                         return ((gensec_gssapi_state->sasl_protection & NEG_SEAL)
1104                                  && (gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG));
1105                 }
1106                 return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
1107         }
1108         if (feature & GENSEC_FEATURE_SESSION_KEY) {
1109                 /* Only for GSSAPI/Krb5 */
1110                 if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
1111                     && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements, gensec_gssapi_state->gss_oid->length) == 0)) {
1112                         return True;
1113                 }
1114         }
1115         if (feature & GENSEC_FEATURE_DCE_STYLE) {
1116                 return gensec_gssapi_state->got_flags & GSS_C_DCE_STYLE;
1117         }
1118         /* We can always do async (rather than strict request/reply) packets.  */
1119         if (feature & GENSEC_FEATURE_ASYNC_REPLIES) {
1120                 return True;
1121         }
1122         return False;
1123 }
1124
1125 /*
1126  * Extract the 'sesssion key' needed by SMB signing and ncacn_np
1127  * (for encrypting some passwords).
1128  *
1129  * This breaks all the abstractions, but what do you expect...
1130  */
1131 static NTSTATUS gensec_gssapi_session_key(struct gensec_security *gensec_security,
1132                                           DATA_BLOB *session_key)
1133 {
1134         struct gensec_gssapi_state *gensec_gssapi_state
1135                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1136         OM_uint32 maj_stat, min_stat;
1137         krb5_keyblock *subkey;
1138
1139         if (gensec_gssapi_state->session_key.data) {
1140                 *session_key = gensec_gssapi_state->session_key;
1141                 return NT_STATUS_OK;
1142         }
1143
1144         maj_stat = gsskrb5_get_initiator_subkey(&min_stat,
1145                                                 gensec_gssapi_state->gssapi_context,
1146                                                 &subkey);
1147         if (maj_stat != 0) {
1148                 DEBUG(1, ("NO session key for this mech\n"));
1149                 return NT_STATUS_NO_USER_SESSION_KEY;
1150         }
1151
1152         DEBUG(10, ("Got KRB5 session key of length %d\n",
1153                    (int)KRB5_KEY_LENGTH(subkey)));
1154         gensec_gssapi_state->session_key = data_blob_talloc(gensec_gssapi_state,
1155                                                             KRB5_KEY_DATA(subkey), KRB5_KEY_LENGTH(subkey));
1156         krb5_free_keyblock(gensec_gssapi_state->smb_krb5_context->krb5_context, subkey);
1157         *session_key = gensec_gssapi_state->session_key;
1158         dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
1159
1160         return NT_STATUS_OK;
1161 }
1162
1163 /* Get some basic (and authorization) information about the user on
1164  * this session.  This uses either the PAC (if present) or a local
1165  * database lookup */
1166 static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_security,
1167                                            struct auth_session_info **_session_info)
1168 {
1169         NTSTATUS nt_status;
1170         TALLOC_CTX *mem_ctx;
1171         struct gensec_gssapi_state *gensec_gssapi_state
1172                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1173         struct auth_serversupplied_info *server_info = NULL;
1174         struct auth_session_info *session_info = NULL;
1175         struct PAC_LOGON_INFO *logon_info;
1176         OM_uint32 maj_stat, min_stat;
1177         gss_buffer_desc name_token;
1178         gss_buffer_desc pac;
1179         krb5_keyblock *keyblock;
1180         time_t authtime;
1181         krb5_principal principal;
1182         char *principal_string;
1183         DATA_BLOB pac_blob;
1184
1185         if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
1186             || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
1187                        gensec_gssapi_state->gss_oid->length) != 0)) {
1188                 DEBUG(1, ("NO session info available for this mech\n"));
1189                 return NT_STATUS_INVALID_PARAMETER;
1190         }
1191
1192         mem_ctx = talloc_named(gensec_gssapi_state, 0, "gensec_gssapi_session_info context");
1193         NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
1194
1195         maj_stat = gss_display_name (&min_stat,
1196                                      gensec_gssapi_state->client_name,
1197                                      &name_token,
1198                                      NULL);
1199         if (GSS_ERROR(maj_stat)) {
1200                 DEBUG(1, ("GSS display_name failed: %s\n",
1201                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1202                 talloc_free(mem_ctx);
1203                 return NT_STATUS_FOOBAR;
1204         }
1205
1206         principal_string = talloc_strndup(mem_ctx, name_token.value, name_token.length);
1207
1208         gss_release_buffer(&min_stat, &name_token);
1209
1210         if (!principal_string) {
1211                 talloc_free(mem_ctx);
1212                 return NT_STATUS_NO_MEMORY;
1213         }
1214
1215         maj_stat = gsskrb5_extract_authz_data_from_sec_context(&min_stat,
1216                                                                gensec_gssapi_state->gssapi_context,
1217                                                                KRB5_AUTHDATA_WIN2K_PAC,
1218                                                                &pac);
1219
1220
1221         if (maj_stat == 0) {
1222                 pac_blob = data_blob_talloc(mem_ctx, pac.value, pac.length);
1223                 gss_release_buffer(&min_stat, &pac);
1224
1225         } else {
1226                 pac_blob = data_blob(NULL, 0);
1227         }
1228
1229         /* IF we have the PAC - otherwise we need to get this
1230          * data from elsewere - local ldb, or (TODO) lookup of some
1231          * kind...
1232          */
1233         if (pac_blob.length) {
1234                 krb5_error_code ret;
1235                 union netr_Validation validation;
1236
1237                 maj_stat = gsskrb5_extract_authtime_from_sec_context(&min_stat,
1238                                                                      gensec_gssapi_state->gssapi_context,
1239                                                                      &authtime);
1240
1241                 if (GSS_ERROR(maj_stat)) {
1242                         DEBUG(1, ("gsskrb5_extract_authtime_from_sec_context: %s\n",
1243                                   gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1244                         talloc_free(mem_ctx);
1245                         return NT_STATUS_FOOBAR;
1246                 }
1247
1248                 maj_stat = gsskrb5_extract_service_keyblock(&min_stat,
1249                                                             gensec_gssapi_state->gssapi_context,
1250                                                             &keyblock);
1251
1252                 if (GSS_ERROR(maj_stat)) {
1253                         DEBUG(1, ("gsskrb5_copy_service_keyblock failed: %s\n",
1254                                   gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1255                         talloc_free(mem_ctx);
1256                         return NT_STATUS_FOOBAR;
1257                 }
1258
1259                 ret = krb5_parse_name_flags(gensec_gssapi_state->smb_krb5_context->krb5_context,
1260                                             principal_string,
1261                                             KRB5_PRINCIPAL_PARSE_MUST_REALM,
1262                                             &principal);
1263                 if (ret) {
1264                         krb5_free_keyblock(gensec_gssapi_state->smb_krb5_context->krb5_context,
1265                                            keyblock);
1266                         talloc_free(mem_ctx);
1267                         return NT_STATUS_INVALID_PARAMETER;
1268                 }
1269
1270                 /* decode and verify the pac */
1271                 nt_status = kerberos_pac_logon_info(mem_ctx, &logon_info, pac_blob,
1272                                                     gensec_gssapi_state->smb_krb5_context->krb5_context,
1273                                                     NULL, keyblock, principal, authtime, NULL);
1274                 krb5_free_principal(gensec_gssapi_state->smb_krb5_context->krb5_context, principal);
1275                 krb5_free_keyblock(gensec_gssapi_state->smb_krb5_context->krb5_context,
1276                                    keyblock);
1277
1278                 if (!NT_STATUS_IS_OK(nt_status)) {
1279                         talloc_free(mem_ctx);
1280                         return nt_status;
1281                 }
1282                 validation.sam3 = &logon_info->info3;
1283                 nt_status = make_server_info_netlogon_validation(gensec_gssapi_state,
1284                                                                  NULL,
1285                                                                  3, &validation,
1286                                                                  &server_info);
1287                 if (!NT_STATUS_IS_OK(nt_status)) {
1288                         talloc_free(mem_ctx);
1289                         return nt_status;
1290                 }
1291         } else if (!lp_parm_bool(-1, "gensec", "require_pac", False)) {
1292                 DEBUG(1, ("Unable to find PAC, resorting to local user lookup: %s\n",
1293                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1294                 nt_status = sam_get_server_info_principal(mem_ctx, principal_string,
1295                                                           &server_info);
1296
1297                 if (!NT_STATUS_IS_OK(nt_status)) {
1298                         talloc_free(mem_ctx);
1299                         return nt_status;
1300                 }
1301         } else {
1302                 DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access: %s\n",
1303                           principal_string,
1304                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1305                 return NT_STATUS_ACCESS_DENIED;
1306         }
1307
1308         /* references the server_info into the session_info */
1309         nt_status = auth_generate_session_info(mem_ctx, server_info, &session_info);
1310         if (!NT_STATUS_IS_OK(nt_status)) {
1311                 talloc_free(mem_ctx);
1312                 return nt_status;
1313         }
1314
1315         nt_status = gensec_gssapi_session_key(gensec_security, &session_info->session_key);
1316         if (!NT_STATUS_IS_OK(nt_status)) {
1317                 talloc_free(mem_ctx);
1318                 return nt_status;
1319         }
1320
1321         if (!(gensec_gssapi_state->got_flags & GSS_C_DELEG_FLAG)) {
1322                 DEBUG(10, ("gensec_gssapi: NO delegated credentials supplied by client\n"));
1323         } else {
1324                 krb5_error_code ret;
1325                 DEBUG(10, ("gensec_gssapi: delegated credentials supplied by client\n"));
1326                 session_info->credentials = cli_credentials_init(session_info);
1327                 if (!session_info->credentials) {
1328                         talloc_free(mem_ctx);
1329                         return NT_STATUS_NO_MEMORY;
1330                 }
1331
1332                 cli_credentials_set_conf(session_info->credentials);
1333
1334                 ret = cli_credentials_set_client_gss_creds(session_info->credentials,
1335                                                            gensec_gssapi_state->delegated_cred_handle,
1336                                                            CRED_SPECIFIED);
1337                 if (ret) {
1338                         talloc_free(mem_ctx);
1339                         return NT_STATUS_NO_MEMORY;
1340                 }
1341                 /* It has been taken from this place... */
1342                 gensec_gssapi_state->delegated_cred_handle = GSS_C_NO_CREDENTIAL;
1343         }
1344         talloc_steal(gensec_gssapi_state, session_info);
1345         talloc_free(mem_ctx);
1346         *_session_info = session_info;
1347
1348         return NT_STATUS_OK;
1349 }
1350
1351 static const char *gensec_gssapi_krb5_oids[] = {
1352         GENSEC_OID_KERBEROS5,
1353         GENSEC_OID_KERBEROS5_OLD,
1354         NULL
1355 };
1356
1357 /* As a server, this could in theory accept any GSSAPI mech */
1358 static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
1359         .name           = "gssapi_krb5",
1360         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
1361         .oid            = gensec_gssapi_krb5_oids,
1362         .client_start   = gensec_gssapi_client_start,
1363         .server_start   = gensec_gssapi_server_start,
1364         .magic          = gensec_gssapi_magic,
1365         .update         = gensec_gssapi_update,
1366         .session_key    = gensec_gssapi_session_key,
1367         .session_info   = gensec_gssapi_session_info,
1368         .sign_packet    = gensec_gssapi_sign_packet,
1369         .check_packet   = gensec_gssapi_check_packet,
1370         .seal_packet    = gensec_gssapi_seal_packet,
1371         .unseal_packet  = gensec_gssapi_unseal_packet,
1372         .wrap           = gensec_gssapi_wrap,
1373         .unwrap         = gensec_gssapi_unwrap,
1374         .have_feature   = gensec_gssapi_have_feature,
1375         .enabled        = True,
1376         .kerberos       = True,
1377         .priority       = GENSEC_GSSAPI
1378 };
1379
1380 /* As a server, this could in theory accept any GSSAPI mech */
1381 static const struct gensec_security_ops gensec_gssapi_sasl_krb5_security_ops = {
1382         .name             = "gssapi_krb5_sasl",
1383         .sasl_name        = "GSSAPI",
1384         .client_start     = gensec_gssapi_sasl_client_start,
1385         .server_start     = gensec_gssapi_sasl_server_start,
1386         .update           = gensec_gssapi_update,
1387         .session_key      = gensec_gssapi_session_key,
1388         .session_info     = gensec_gssapi_session_info,
1389         .max_input_size   = gensec_gssapi_max_input_size,
1390         .max_wrapped_size = gensec_gssapi_max_wrapped_size,
1391         .wrap             = gensec_gssapi_wrap,
1392         .unwrap           = gensec_gssapi_unwrap,
1393         .have_feature     = gensec_gssapi_have_feature,
1394         .enabled          = True,
1395         .kerberos         = True,
1396         .priority         = GENSEC_GSSAPI
1397 };
1398
1399 NTSTATUS gensec_gssapi_init(void)
1400 {
1401         NTSTATUS ret;
1402
1403         ret = gensec_register(&gensec_gssapi_krb5_security_ops);
1404         if (!NT_STATUS_IS_OK(ret)) {
1405                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1406                         gensec_gssapi_krb5_security_ops.name));
1407                 return ret;
1408         }
1409
1410         ret = gensec_register(&gensec_gssapi_sasl_krb5_security_ops);
1411         if (!NT_STATUS_IS_OK(ret)) {
1412                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1413                         gensec_gssapi_sasl_krb5_security_ops.name));
1414                 return ret;
1415         }
1416
1417         return ret;
1418 }