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 "auth/kerberos/kerberos.h"
  28 #include "librpc/gen_ndr/krb5pac.h"
  29 #include "auth/auth.h"
  30 #include "lib/ldb/include/ldb.h"
  31 #include "auth/auth_sam.h"
  32 #include "librpc/rpc/dcerpc.h"
  33
  34 enum gensec_gssapi_sasl_state
  35 {
  36         STAGE_GSS_NEG,
  37         STAGE_SASL_SSF_NEG,
  38         STAGE_SASL_SSF_ACCEPT,
  39         STAGE_DONE
  40 };
  41
  42 #define NEG_SEAL 0x4
  43 #define NEG_SIGN 0x2
  44 #define NEG_NONE 0x1
  45
  46 struct gensec_gssapi_state {
  47         gss_ctx_id_t gssapi_context;
  48         struct gss_channel_bindings_struct *input_chan_bindings;
  49         gss_name_t server_name;
  50         gss_name_t client_name;
  51         OM_uint32 want_flags, got_flags;
  52         const gss_OID_desc *gss_oid;
  53
  54         DATA_BLOB session_key;
  55         DATA_BLOB pac;
  56
  57         struct smb_krb5_context *smb_krb5_context;
  58         struct gssapi_creds_container *client_cred;
  59         struct gssapi_creds_container *server_cred;
  60
  61         gss_cred_id_t delegated_cred_handle;
  62
  63         BOOL sasl; /* We have two different mechs in this file: One
  64                     * for SASL wrapped GSSAPI and another for normal
  65                     * GSSAPI */
  66         enum gensec_gssapi_sasl_state sasl_state;
  67         uint8_t sasl_protection; /* What was negotiated at the SASL
  68                                   * layer, independent of the GSSAPI
  69                                   * layer... */
  70
  71         size_t max_wrap_buf_size;
  72 };
  73
  74 static size_t gensec_gssapi_max_input_size(struct gensec_security *gensec_security);
  75 static size_t gensec_gssapi_max_wrapped_size(struct gensec_security *gensec_security);
  76
  77 static char *gssapi_error_string(TALLOC_CTX *mem_ctx,
  78                                  OM_uint32 maj_stat, OM_uint32 min_stat)
  79 {
  80         OM_uint32 disp_min_stat, disp_maj_stat;
  81         gss_buffer_desc maj_error_message;
  82         gss_buffer_desc min_error_message;
  83         OM_uint32 msg_ctx = 0;
  84
  85         char *ret;
  86
  87         maj_error_message.value = NULL;
  88         min_error_message.value = NULL;
  89
  90         disp_maj_stat = gss_display_status(&disp_min_stat, maj_stat, GSS_C_GSS_CODE,
  91                            GSS_C_NULL_OID, &msg_ctx, &maj_error_message);
  92         disp_maj_stat = gss_display_status(&disp_min_stat, min_stat, GSS_C_MECH_CODE,
  93                            GSS_C_NULL_OID, &msg_ctx, &min_error_message);
  94         ret = talloc_asprintf(mem_ctx, "%s: %s", (char *)maj_error_message.value, (char *)min_error_message.value);
  95
  96         gss_release_buffer(&disp_min_stat, &maj_error_message);
  97         gss_release_buffer(&disp_min_stat, &min_error_message);
  98
  99         return ret;
 100 }
 101
 102
 103 static int gensec_gssapi_destory(struct gensec_gssapi_state *gensec_gssapi_state)
 104 {
 105         OM_uint32 maj_stat, min_stat;
 106
 107         if (gensec_gssapi_state->delegated_cred_handle != GSS_C_NO_CREDENTIAL) {
 108                 maj_stat = gss_release_cred(&min_stat,
 109                                             &gensec_gssapi_state->delegated_cred_handle);
 110         }
 111
 112         if (gensec_gssapi_state->gssapi_context != GSS_C_NO_CONTEXT) {
 113                 maj_stat = gss_delete_sec_context (&min_stat,
 114                                                    &gensec_gssapi_state->gssapi_context,
 115                                                    GSS_C_NO_BUFFER);
 116         }
 117
 118         if (gensec_gssapi_state->server_name != GSS_C_NO_NAME) {
 119                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->server_name);
 120         }
 121         if (gensec_gssapi_state->client_name != GSS_C_NO_NAME) {
 122                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->client_name);
 123         }
 124         return 0;
 125 }
 126
 127 static NTSTATUS gensec_gssapi_start(struct gensec_security *gensec_security)
 128 {
 129         struct gensec_gssapi_state *gensec_gssapi_state;
 130         krb5_error_code ret;
 131
 132         gensec_gssapi_state = talloc(gensec_security, struct gensec_gssapi_state);
 133         if (!gensec_gssapi_state) {
 134                 return NT_STATUS_NO_MEMORY;
 135         }
 136
 137         gensec_gssapi_state->max_wrap_buf_size
 138                 = lp_parm_int(-1, "gensec_gssapi", "max wrap buf size", 65536);
 139
 140         gensec_gssapi_state->sasl = False;
 141         gensec_gssapi_state->sasl_state = STAGE_GSS_NEG;
 142
 143         gensec_security->private_data = gensec_gssapi_state;
 144
 145         gensec_gssapi_state->gssapi_context = GSS_C_NO_CONTEXT;
 146         gensec_gssapi_state->server_name = GSS_C_NO_NAME;
 147         gensec_gssapi_state->client_name = GSS_C_NO_NAME;
 148
 149         /* TODO: Fill in channel bindings */
 150         gensec_gssapi_state->input_chan_bindings = GSS_C_NO_CHANNEL_BINDINGS;
 151
 152         gensec_gssapi_state->want_flags = 0;
 153         if (lp_parm_bool(-1, "gensec_gssapi", "mutual", True)) {
 154                 gensec_gssapi_state->want_flags |= GSS_C_MUTUAL_FLAG;
 155         }
 156         if (lp_parm_bool(-1, "gensec_gssapi", "delegation", True)) {
 157                 gensec_gssapi_state->want_flags |= GSS_C_DELEG_FLAG;
 158         }
 159         if (lp_parm_bool(-1, "gensec_gssapi", "sequence", True)) {
 160                 gensec_gssapi_state->want_flags |= GSS_C_SEQUENCE_FLAG;
 161         }
 162
 163         gensec_gssapi_state->got_flags = 0;
 164
 165         gensec_gssapi_state->session_key = data_blob(NULL, 0);
 166         gensec_gssapi_state->pac = data_blob(NULL, 0);
 167
 168         gensec_gssapi_state->delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 169
 170         talloc_set_destructor(gensec_gssapi_state, gensec_gssapi_destory);
 171
 172         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 173                 gensec_gssapi_state->want_flags |= GSS_C_INTEG_FLAG;
 174         }
 175         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 176                 gensec_gssapi_state->want_flags |= GSS_C_CONF_FLAG;
 177         }
 178         if (gensec_security->want_features & GENSEC_FEATURE_DCE_STYLE) {
 179                 gensec_gssapi_state->want_flags |= GSS_C_DCE_STYLE;
 180         }
 181
 182         gensec_gssapi_state->gss_oid = gss_mech_krb5;
 183
 184         ret = smb_krb5_init_context(gensec_gssapi_state,
 185                                     &gensec_gssapi_state->smb_krb5_context);
 186         if (ret) {
 187                 DEBUG(1,("gensec_krb5_start: krb5_init_context failed (%s)\n",
 188                          error_message(ret)));
 189                 return NT_STATUS_INTERNAL_ERROR;
 190         }
 191         return NT_STATUS_OK;
 192 }
 193
 194 static NTSTATUS gensec_gssapi_server_start(struct gensec_security *gensec_security)
 195 {
 196         NTSTATUS nt_status;
 197         int ret;
 198         struct gensec_gssapi_state *gensec_gssapi_state;
 199         struct cli_credentials *machine_account;
 200         struct gssapi_creds_container *gcc;
 201
 202         nt_status = gensec_gssapi_start(gensec_security);
 203         if (!NT_STATUS_IS_OK(nt_status)) {
 204                 return nt_status;
 205         }
 206
 207         gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 208
 209         machine_account = gensec_get_credentials(gensec_security);
 210
 211         if (!machine_account) {
 212                 DEBUG(3, ("No machine account credentials specified\n"));
 213                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 214         } else {
 215                 ret = cli_credentials_get_server_gss_creds(machine_account, &gcc);
 216                 if (ret) {
 217                         DEBUG(1, ("Aquiring acceptor credentials failed: %s\n",
 218                                   error_message(ret)));
 219                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 220                 }
 221         }
 222
 223         gensec_gssapi_state->server_cred = gcc;
 224         return NT_STATUS_OK;
 225
 226 }
 227
 228 static NTSTATUS gensec_gssapi_sasl_server_start(struct gensec_security *gensec_security)
 229 {
 230         NTSTATUS nt_status;
 231         struct gensec_gssapi_state *gensec_gssapi_state;
 232         nt_status = gensec_gssapi_server_start(gensec_security);
 233
 234         if (NT_STATUS_IS_OK(nt_status)) {
 235                 gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 236                 gensec_gssapi_state->sasl = True;
 237         }
 238         return nt_status;
 239 }
 240
 241 static NTSTATUS gensec_gssapi_client_start(struct gensec_security *gensec_security)
 242 {
 243         struct gensec_gssapi_state *gensec_gssapi_state;
 244         struct cli_credentials *creds = gensec_get_credentials(gensec_security);
 245         krb5_error_code ret;
 246         NTSTATUS nt_status;
 247         gss_buffer_desc name_token;
 248         gss_OID name_type;
 249         OM_uint32 maj_stat, min_stat;
 250         const char *hostname = gensec_get_target_hostname(gensec_security);
 251         const char *principal;
 252         struct gssapi_creds_container *gcc;
 253
 254         if (!hostname) {
 255                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 256                 return NT_STATUS_INVALID_PARAMETER;
 257         }
 258         if (is_ipaddress(hostname)) {
 259                 DEBUG(2, ("Cannot do GSSAPI to an IP address\n"));
 260                 return NT_STATUS_INVALID_PARAMETER;
 261         }
 262         if (strcmp(hostname, "localhost") == 0) {
 263                 DEBUG(2, ("GSSAPI to 'localhost' does not make sense\n"));
 264                 return NT_STATUS_INVALID_PARAMETER;
 265         }
 266
 267         if (((gensec_security->want_features & GENSEC_FEATURE_SIGN)
 268              || (gensec_security->want_features & GENSEC_FEATURE_SEAL))
 269             && (gensec_security->want_features & GENSEC_FEATURE_DCE_STYLE)
 270             && !lp_parm_bool(-1, "gensec_gssapi", "dce_signseal",
 271                              cli_credentials_get_kerberos_state(creds) == CRED_MUST_USE_KERBEROS)) {
 272                 DEBUG(2, ("GSSAPI sign/seal disabled for DCE/RPC. "));
 273                 return NT_STATUS_INVALID_PARAMETER;
 274         }
 275
 276         nt_status = gensec_gssapi_start(gensec_security);
 277         if (!NT_STATUS_IS_OK(nt_status)) {
 278                 return nt_status;
 279         }
 280
 281         gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 282
 283         principal = gensec_get_target_principal(gensec_security);
 284         if (principal && lp_client_use_spnego_principal()) {
 285                 name_token.value  = discard_const_p(uint8_t, principal);
 286                 name_token.length = strlen(principal);
 287
 288                 name_type = GSS_C_NULL_OID;
 289         } else {
 290                 principal = talloc_asprintf(gensec_gssapi_state, "%s@%s",
 291                                             gensec_get_target_service(gensec_security),
 292                                             hostname);
 293
 294                 name_token.value  = discard_const_p(uint8_t, principal);
 295                 name_token.length = strlen(principal);
 296
 297                 name_type = GSS_C_NT_HOSTBASED_SERVICE;
 298         }
 299
 300         maj_stat = gss_import_name (&min_stat,
 301                                     &name_token,
 302                                     name_type,
 303                                     &gensec_gssapi_state->server_name);
 304         if (maj_stat) {
 305                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 306                           (char *)name_token.value,
 307                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 308                 return NT_STATUS_INVALID_PARAMETER;
 309         }
 310
 311         ret = cli_credentials_get_client_gss_creds(creds, &gcc);
 312         switch (ret) {
 313         case 0:
 314                 break;
 315         case KRB5_KDC_UNREACH:
 316                 DEBUG(3, ("Cannot reach a KDC we require\n"));
 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\n"));
 320                 return NT_STATUS_UNSUCCESSFUL;
 321         }
 322
 323         gensec_gssapi_state->client_cred = gcc;
 324
 325         return NT_STATUS_OK;
 326 }
 327
 328 static NTSTATUS gensec_gssapi_sasl_client_start(struct gensec_security *gensec_security)
 329 {
 330         NTSTATUS nt_status;
 331         struct gensec_gssapi_state *gensec_gssapi_state;
 332         nt_status = gensec_gssapi_client_start(gensec_security);
 333
 334         if (NT_STATUS_IS_OK(nt_status)) {
 335                 gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 336                 gensec_gssapi_state->sasl = True;
 337         }
 338         return nt_status;
 339 }
 340
 341
 342 /**
 343  * Check if the packet is one for this mechansim
 344  *
 345  * @param gensec_security GENSEC state
 346  * @param in The request, as a DATA_BLOB
 347  * @return Error, INVALID_PARAMETER if it's not a packet for us
 348  *                or NT_STATUS_OK if the packet is ok.
 349  */
 350
 351 static NTSTATUS gensec_gssapi_magic(struct gensec_security *gensec_security,
 352                                     const DATA_BLOB *in)
 353 {
 354         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 355                 return NT_STATUS_OK;
 356         } else {
 357                 return NT_STATUS_INVALID_PARAMETER;
 358         }
 359 }
 360
 361
 362 /**
 363  * Next state function for the GSSAPI GENSEC mechanism
 364  *
 365  * @param gensec_gssapi_state GSSAPI State
 366  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 367  * @param in The request, as a DATA_BLOB
 368  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 369  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 370  *                or NT_STATUS_OK if the user is authenticated.
 371  */
 372
 373 static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 374                                    TALLOC_CTX *out_mem_ctx,
 375                                    const DATA_BLOB in, DATA_BLOB *out)
 376 {
 377         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 378         NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
 379         OM_uint32 maj_stat, min_stat;
 380         OM_uint32 min_stat2;
 381         gss_buffer_desc input_token, output_token;
 382         gss_OID gss_oid_p;
 383         input_token.length = in.length;
 384         input_token.value = in.data;
 385
 386         switch (gensec_gssapi_state->sasl_state) {
 387         case STAGE_GSS_NEG:
 388         {
 389                 switch (gensec_security->gensec_role) {
 390                 case GENSEC_CLIENT:
 391                 {
 392                         maj_stat = gss_init_sec_context(&min_stat,
 393                                                         gensec_gssapi_state->client_cred->creds,
 394                                                         &gensec_gssapi_state->gssapi_context,
 395                                                         gensec_gssapi_state->server_name,
 396                                                         discard_const_p(gss_OID_desc, gensec_gssapi_state->gss_oid),
 397                                                         gensec_gssapi_state->want_flags,
 398                                                         0,
 399                                                         gensec_gssapi_state->input_chan_bindings,
 400                                                         &input_token,
 401                                                         NULL,
 402                                                         &output_token,
 403                                                         &gensec_gssapi_state->got_flags, /* ret flags */
 404                                                         NULL);
 405                         break;
 406                 }
 407                 case GENSEC_SERVER:
 408                 {
 409                         maj_stat = gss_accept_sec_context(&min_stat,
 410                                                           &gensec_gssapi_state->gssapi_context,
 411                                                           gensec_gssapi_state->server_cred->creds,
 412                                                           &input_token,
 413                                                           gensec_gssapi_state->input_chan_bindings,
 414                                                           &gensec_gssapi_state->client_name,
 415                                                           &gss_oid_p,
 416                                                           &output_token,
 417                                                           &gensec_gssapi_state->got_flags,
 418                                                           NULL,
 419                                                           &gensec_gssapi_state->delegated_cred_handle);
 420                         gensec_gssapi_state->gss_oid = gss_oid_p;
 421                         break;
 422                 }
 423                 default:
 424                         return NT_STATUS_INVALID_PARAMETER;
 425
 426                 }
 427
 428                 if (maj_stat == GSS_S_COMPLETE) {
 429                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 430                         gss_release_buffer(&min_stat2, &output_token);
 431
 432                         if (gensec_gssapi_state->got_flags & GSS_C_DELEG_FLAG) {
 433                                 DEBUG(5, ("gensec_gssapi: credentials were delegated\n"));
 434                         } else {
 435                                 DEBUG(5, ("gensec_gssapi: NO credentials were delegated\n"));
 436                         }
 437
 438                         /* We may have been invoked as SASL, so there
 439                          * is more work to do */
 440                         if (gensec_gssapi_state->sasl) {
 441                                 /* Due to a very subtle interaction
 442                                  * with SASL and the LDAP libs, we
 443                                  * must ensure the data pointer is
 444                                  * != NULL, but the length is 0.
 445                                  *
 446                                  * This ensures we send a 'zero
 447                                  * length' (rather than NULL) response
 448                                  */
 449
 450                                 if (!out->data) {
 451                                         out->data = (uint8_t *)talloc_strdup(out_mem_ctx, "\0");
 452                                 }
 453
 454                                 gensec_gssapi_state->sasl_state = STAGE_SASL_SSF_NEG;
 455                                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 456                         } else {
 457                                 gensec_gssapi_state->sasl_state = STAGE_DONE;
 458
 459                                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 460                                         DEBUG(5, ("GSSAPI Connection will be cryptographicly sealed\n"));
 461                                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 462                                         DEBUG(5, ("GSSAPI Connection will be cryptographicly signed\n"));
 463                                 } else {
 464                                         DEBUG(5, ("GSSAPI Connection will have no cryptographic protection\n"));
 465                                 }
 466
 467                                 return NT_STATUS_OK;
 468                         }
 469                 } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 470                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 471                         gss_release_buffer(&min_stat2, &output_token);
 472
 473                         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 474                 } else if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 475                            && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 476                                       gensec_gssapi_state->gss_oid->length) == 0)) {
 477                         switch (min_stat) {
 478                         case KRB5_KDC_UNREACH:
 479                                 DEBUG(3, ("Cannot reach a KDC we require: %s\n",
 480                                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 481                                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 482                         case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 483                                 DEBUG(3, ("Server is not registered with our KDC: %s\n",
 484                                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 485                                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 486                         case KRB5KRB_AP_ERR_MSG_TYPE:
 487                                 /* garbage input, possibly from the auto-mech detection */
 488                                 return NT_STATUS_INVALID_PARAMETER;
 489                         default:
 490                                 DEBUG(1, ("GSS(krb5) Update failed: %s\n",
 491                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 492                                 return nt_status;
 493                         }
 494                 } else {
 495                         DEBUG(1, ("GSS Update failed: %s\n",
 496                                   gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 497                         return nt_status;
 498                 }
 499                 break;
 500         }
 501
 502         /* These last two stages are only done if we were invoked as SASL */
 503         case STAGE_SASL_SSF_NEG:
 504         {
 505                 switch (gensec_security->gensec_role) {
 506                 case GENSEC_CLIENT:
 507                 {
 508                         uint8_t maxlength_proposed[4];
 509                         uint8_t maxlength_accepted[4];
 510                         uint8_t security_supported;
 511                         int conf_state;
 512                         gss_qop_t qop_state;
 513                         input_token.length = in.length;
 514                         input_token.value = in.data;
 515
 516                         /* As a client, we have just send a
 517                          * zero-length blob to the server (after the
 518                          * normal GSSAPI exchange), and it has replied
 519                          * with it's SASL negotiation */
 520
 521                         maj_stat = gss_unwrap(&min_stat,
 522                                               gensec_gssapi_state->gssapi_context,
 523                                               &input_token,
 524                                               &output_token,
 525                                               &conf_state,
 526                                               &qop_state);
 527                         if (GSS_ERROR(maj_stat)) {
 528                                 DEBUG(1, ("gensec_gssapi_update: GSS UnWrap of SASL protection negotiation failed: %s\n",
 529                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 530                                 return NT_STATUS_ACCESS_DENIED;
 531                         }
 532
 533                         if (output_token.length < 4) {
 534                                 return NT_STATUS_INVALID_PARAMETER;
 535                         }
 536
 537                         memcpy(maxlength_proposed, output_token.value, 4);
 538                         gss_release_buffer(&min_stat, &output_token);
 539
 540                         /* first byte is the proposed security */
 541                         security_supported = maxlength_proposed[0];
 542                         maxlength_proposed[0] = '\0';
 543
 544                         /* Rest is the proposed max wrap length */
 545                         gensec_gssapi_state->max_wrap_buf_size = MIN(RIVAL(maxlength_proposed, 0),
 546                                                                      gensec_gssapi_state->max_wrap_buf_size);
 547                         gensec_gssapi_state->sasl_protection = 0;
 548                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 549                                 if (security_supported & NEG_SEAL) {
 550                                         gensec_gssapi_state->sasl_protection |= NEG_SEAL;
 551                                 }
 552                         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 553                                 if (security_supported & NEG_SIGN) {
 554                                         gensec_gssapi_state->sasl_protection |= NEG_SIGN;
 555                                 }
 556                         } else if (security_supported & NEG_NONE) {
 557                                 gensec_gssapi_state->sasl_protection |= NEG_NONE;
 558                         } else {
 559                                 DEBUG(1, ("Remote server does not support unprotected connections"));
 560                                 return NT_STATUS_ACCESS_DENIED;
 561                         }
 562
 563                         /* Send back the negotiated max length */
 564
 565                         RSIVAL(maxlength_accepted, 0, gensec_gssapi_state->max_wrap_buf_size);
 566
 567                         maxlength_accepted[0] = gensec_gssapi_state->sasl_protection;
 568
 569                         input_token.value = maxlength_accepted;
 570                         input_token.length = sizeof(maxlength_accepted);
 571
 572                         maj_stat = gss_wrap(&min_stat,
 573                                             gensec_gssapi_state->gssapi_context,
 574                                             False,
 575                                             GSS_C_QOP_DEFAULT,
 576                                             &input_token,
 577                                             &conf_state,
 578                                             &output_token);
 579                         if (GSS_ERROR(maj_stat)) {
 580                                 DEBUG(1, ("gensec_gssapi_wrap: GSS Wrap failed: %s\n",
 581                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 582                                 return NT_STATUS_ACCESS_DENIED;
 583                         }
 584
 585                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 586                         gss_release_buffer(&min_stat, &output_token);
 587
 588                         /* quirk:  This changes the value that gensec_have_feature returns, to be that after SASL negotiation */
 589                         gensec_gssapi_state->sasl_state = STAGE_DONE;
 590
 591                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 592                                 DEBUG(3, ("SASL/GSSAPI Connection to server will be cryptographicly sealed\n"));
 593                         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 594                                 DEBUG(3, ("SASL/GSSAPI Connection to server will be cryptographicly signed\n"));
 595                         } else {
 596                                 DEBUG(3, ("SASL/GSSAPI Connection to server will have no cryptographicly protection\n"));
 597                         }
 598
 599                         return NT_STATUS_OK;
 600                 }
 601                 case GENSEC_SERVER:
 602                 {
 603                         uint8_t maxlength_proposed[4];
 604                         uint8_t security_supported = 0x0;
 605                         int conf_state;
 606
 607                         /* As a server, we have just been sent a zero-length blob (note this, but it isn't fatal) */
 608                         if (in.length != 0) {
 609                                 DEBUG(1, ("SASL/GSSAPI: client sent non-zero length starting SASL negotiation!\n"));
 610                         }
 611
 612                         /* Give the client some idea what we will support */
 613
 614                         RSIVAL(maxlength_proposed, 0, gensec_gssapi_state->max_wrap_buf_size);
 615                         /* first byte is the proposed security */
 616                         maxlength_proposed[0] = '\0';
 617
 618                         gensec_gssapi_state->sasl_protection = 0;
 619                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 620                                 security_supported |= NEG_SEAL;
 621                         }
 622                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 623                                 security_supported |= NEG_SIGN;
 624                         }
 625                         if (security_supported == 0) {
 626                                 /* If we don't support anything, this must be 0 */
 627                                 RSIVAL(maxlength_proposed, 0, 0x0);
 628                         }
 629
 630                         /* TODO:  We may not wish to support this */
 631                         security_supported |= NEG_NONE;
 632                         maxlength_proposed[0] = security_supported;
 633
 634                         input_token.value = maxlength_proposed;
 635                         input_token.length = sizeof(maxlength_proposed);
 636
 637                         maj_stat = gss_wrap(&min_stat,
 638                                             gensec_gssapi_state->gssapi_context,
 639                                             False,
 640                                             GSS_C_QOP_DEFAULT,
 641                                             &input_token,
 642                                             &conf_state,
 643                                             &output_token);
 644                         if (GSS_ERROR(maj_stat)) {
 645                                 DEBUG(1, ("gensec_gssapi_wrap: GSS Wrap failed: %s\n",
 646                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 647                                 return NT_STATUS_ACCESS_DENIED;
 648                         }
 649
 650                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 651                         gss_release_buffer(&min_stat, &output_token);
 652
 653                         gensec_gssapi_state->sasl_state = STAGE_SASL_SSF_ACCEPT;
 654                         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 655                 }
 656                 default:
 657                         return NT_STATUS_INVALID_PARAMETER;
 658
 659                 }
 660         }
 661         /* This is s server-only stage */
 662         case STAGE_SASL_SSF_ACCEPT:
 663         {
 664                 uint8_t maxlength_accepted[4];
 665                 uint8_t security_accepted;
 666                 int conf_state;
 667                 gss_qop_t qop_state;
 668                 input_token.length = in.length;
 669                 input_token.value = in.data;
 670
 671                 maj_stat = gss_unwrap(&min_stat,
 672                                       gensec_gssapi_state->gssapi_context,
 673                                       &input_token,
 674                                       &output_token,
 675                                       &conf_state,
 676                                       &qop_state);
 677                 if (GSS_ERROR(maj_stat)) {
 678                         DEBUG(1, ("gensec_gssapi_update: GSS UnWrap of SASL protection negotiation failed: %s\n",
 679                                   gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 680                         return NT_STATUS_ACCESS_DENIED;
 681                 }
 682
 683                 if (output_token.length < 4) {
 684                         return NT_STATUS_INVALID_PARAMETER;
 685                 }
 686
 687                 memcpy(maxlength_accepted, output_token.value, 4);
 688                 gss_release_buffer(&min_stat, &output_token);
 689
 690                 /* first byte is the proposed security */
 691                 security_accepted = maxlength_accepted[0];
 692                 maxlength_accepted[0] = '\0';
 693
 694                 /* Rest is the proposed max wrap length */
 695                 gensec_gssapi_state->max_wrap_buf_size = MIN(RIVAL(maxlength_accepted, 0),
 696                                                              gensec_gssapi_state->max_wrap_buf_size);
 697
 698                 gensec_gssapi_state->sasl_protection = 0;
 699                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 700                         if (security_accepted & NEG_SEAL) {
 701                                 gensec_gssapi_state->sasl_protection |= NEG_SEAL;
 702                         }
 703                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 704                         if (security_accepted & NEG_SIGN) {
 705                                 gensec_gssapi_state->sasl_protection |= NEG_SIGN;
 706                         }
 707                 } else if (security_accepted & NEG_NONE) {
 708                         gensec_gssapi_state->sasl_protection |= NEG_NONE;
 709                 } else {
 710                         DEBUG(1, ("Remote client does not support unprotected connections, but we failed to negotiate anything better"));
 711                         return NT_STATUS_ACCESS_DENIED;
 712                 }
 713
 714                 /* quirk:  This changes the value that gensec_have_feature returns, to be that after SASL negotiation */
 715                 gensec_gssapi_state->sasl_state = STAGE_DONE;
 716                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 717                         DEBUG(5, ("SASL/GSSAPI Connection from client will be cryptographicly sealed\n"));
 718                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 719                         DEBUG(5, ("SASL/GSSAPI Connection from client will be cryptographicly signed\n"));
 720                 } else {
 721                         DEBUG(5, ("SASL/GSSAPI Connection from client will have no cryptographic protection\n"));
 722                 }
 723
 724                 *out = data_blob(NULL, 0);
 725                 return NT_STATUS_OK;
 726         }
 727         default:
 728                 return NT_STATUS_INVALID_PARAMETER;
 729         }
 730 }
 731
 732 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 733                                    TALLOC_CTX *mem_ctx,
 734                                    const DATA_BLOB *in,
 735                                    DATA_BLOB *out)
 736 {
 737         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 738         OM_uint32 maj_stat, min_stat;
 739         gss_buffer_desc input_token, output_token;
 740         int conf_state;
 741         input_token.length = in->length;
 742         input_token.value = in->data;
 743
 744         maj_stat = gss_wrap(&min_stat,
 745                             gensec_gssapi_state->gssapi_context,
 746                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 747                             GSS_C_QOP_DEFAULT,
 748                             &input_token,
 749                             &conf_state,
 750                             &output_token);
 751         if (GSS_ERROR(maj_stat)) {
 752                 DEBUG(1, ("gensec_gssapi_wrap: GSS Wrap failed: %s\n",
 753                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 754                 return NT_STATUS_ACCESS_DENIED;
 755         }
 756
 757         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 758         gss_release_buffer(&min_stat, &output_token);
 759
 760         if (gensec_gssapi_state->sasl) {
 761                 size_t max_wrapped_size = gensec_gssapi_max_wrapped_size(gensec_security);
 762                 if (max_wrapped_size < out->length) {
 763                         DEBUG(1, ("gensec_gssapi_wrap: when wrapped, INPUT data (%u) is grew to be larger than SASL negotiated maximum output size (%u > %u)\n",
 764                                   in->length,
 765                                   out->length,
 766                                   (unsigned int)max_wrapped_size));
 767                         return NT_STATUS_INVALID_PARAMETER;
 768                 }
 769         }
 770
 771         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 772             && !conf_state) {
 773                 return NT_STATUS_ACCESS_DENIED;
 774         }
 775         return NT_STATUS_OK;
 776 }
 777
 778 static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 779                                      TALLOC_CTX *mem_ctx,
 780                                      const DATA_BLOB *in,
 781                                      DATA_BLOB *out)
 782 {
 783         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 784         OM_uint32 maj_stat, min_stat;
 785         gss_buffer_desc input_token, output_token;
 786         int conf_state;
 787         gss_qop_t qop_state;
 788         input_token.length = in->length;
 789         input_token.value = in->data;
 790
 791         if (gensec_gssapi_state->sasl) {
 792                 size_t max_wrapped_size = gensec_gssapi_max_wrapped_size(gensec_security);
 793                 if (max_wrapped_size < in->length) {
 794                         DEBUG(1, ("gensec_gssapi_unwrap: WRAPPED data is larger than SASL negotiated maximum size\n"));
 795                         return NT_STATUS_INVALID_PARAMETER;
 796                 }
 797         }
 798
 799         maj_stat = gss_unwrap(&min_stat,
 800                               gensec_gssapi_state->gssapi_context,
 801                               &input_token,
 802                               &output_token,
 803                               &conf_state,
 804                               &qop_state);
 805         if (GSS_ERROR(maj_stat)) {
 806                 DEBUG(1, ("gensec_gssapi_unwrap: GSS UnWrap failed: %s\n",
 807                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 808                 return NT_STATUS_ACCESS_DENIED;
 809         }
 810
 811         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 812         gss_release_buffer(&min_stat, &output_token);
 813
 814         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 815             && !conf_state) {
 816                 return NT_STATUS_ACCESS_DENIED;
 817         }
 818         return NT_STATUS_OK;
 819 }
 820
 821 /* Find out the size of the signature, assuming (incorrectly) that it
 822  * GSSAPI provides any guarantees as to it's size.
 823  *
 824  * This is needed by the DCE/RPC code, which uses AEAD
 825  * (signed headers, including signature legnth and a sealed body)
 826  */
 827 static size_t gensec_gssapi_sig_size(struct gensec_security *gensec_security, size_t data_size)
 828 {
 829         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 830         OM_uint32 maj_stat, min_stat;
 831         OM_uint32 output_size;
 832         if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
 833             || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 834                        gensec_gssapi_state->gss_oid->length) != 0)) {
 835                 DEBUG(1, ("NO sig size available for this mech\n"));
 836                 return 0;
 837         }
 838
 839         maj_stat = gsskrb5_wrap_size(&min_stat,
 840                                      gensec_gssapi_state->gssapi_context,
 841                                      gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 842                                      GSS_C_QOP_DEFAULT,
 843                                      data_size,
 844                                      &output_size);
 845         if (GSS_ERROR(maj_stat)) {
 846                 TALLOC_CTX *mem_ctx = talloc_new(NULL);
 847                 DEBUG(1, ("gensec_gssapi_sig_size: determinaing signature size with gsskrb5_wrap_size failed: %s\n",
 848                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 849                 talloc_free(mem_ctx);
 850                 return 0;
 851         }
 852
 853         if (output_size < data_size) {
 854                 return 0;
 855         }
 856
 857         /* The difference between the max output and the max input must be the signature */
 858         return output_size - data_size;
 859 }
 860
 861 /* Find out the maximum input size negotiated on this connection */
 862
 863 static size_t gensec_gssapi_max_input_size(struct gensec_security *gensec_security)
 864 {
 865         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 866         OM_uint32 maj_stat, min_stat;
 867         OM_uint32 max_input_size;
 868
 869         maj_stat = gss_wrap_size_limit(&min_stat,
 870                                        gensec_gssapi_state->gssapi_context,
 871                                        gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 872                                        GSS_C_QOP_DEFAULT,
 873                                        gensec_gssapi_state->max_wrap_buf_size,
 874                                        &max_input_size);
 875         if (GSS_ERROR(maj_stat)) {
 876                 TALLOC_CTX *mem_ctx = talloc_new(NULL);
 877                 DEBUG(1, ("gensec_gssapi_max_input_size: determinaing signature size with gss_wrap_size_limit failed: %s\n",
 878                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 879                 talloc_free(mem_ctx);
 880                 return 0;
 881         }
 882
 883         return max_input_size;
 884 }
 885
 886 /* Find out the maximum output size negotiated on this connection */
 887 static size_t gensec_gssapi_max_wrapped_size(struct gensec_security *gensec_security)
 888 {
 889         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 890         return gensec_gssapi_state->max_wrap_buf_size;
 891 }
 892
 893 static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_security,
 894                                           TALLOC_CTX *mem_ctx,
 895                                           uint8_t *data, size_t length,
 896                                           const uint8_t *whole_pdu, size_t pdu_length,
 897                                           DATA_BLOB *sig)
 898 {
 899         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 900         OM_uint32 maj_stat, min_stat;
 901         gss_buffer_desc input_token, output_token;
 902         int conf_state;
 903         ssize_t sig_length;
 904
 905         input_token.length = length;
 906         input_token.value = data;
 907
 908         maj_stat = gss_wrap(&min_stat,
 909                             gensec_gssapi_state->gssapi_context,
 910                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 911                             GSS_C_QOP_DEFAULT,
 912                             &input_token,
 913                             &conf_state,
 914                             &output_token);
 915         if (GSS_ERROR(maj_stat)) {
 916                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap failed: %s\n",
 917                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 918                 return NT_STATUS_ACCESS_DENIED;
 919         }
 920
 921         sig_length = gensec_gssapi_sig_size(gensec_security, length);
 922
 923         /* Caller must pad to right boundary */
 924         if (output_token.length != (length + sig_length)) {
 925                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap length [%ld] does not match caller length [%ld] plus sig size [%ld] = [%ld]\n",
 926                           (long)output_token.length, (long)length, (long)sig_length, (long)(length + sig_length)));
 927                 return NT_STATUS_INTERNAL_ERROR;
 928         }
 929
 930         memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);
 931         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 932
 933         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 934         dump_data_pw("gensec_gssapi_seal_packet: clear\n", data, length);
 935         dump_data_pw("gensec_gssapi_seal_packet: sealed\n", ((uint8_t *)output_token.value) + sig_length, output_token.length - sig_length);
 936
 937         gss_release_buffer(&min_stat, &output_token);
 938
 939         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 940             && !conf_state) {
 941                 return NT_STATUS_ACCESS_DENIED;
 942         }
 943         return NT_STATUS_OK;
 944 }
 945
 946 static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_security,
 947                                             TALLOC_CTX *mem_ctx,
 948                                             uint8_t *data, size_t length,
 949                                             const uint8_t *whole_pdu, size_t pdu_length,
 950                                             const DATA_BLOB *sig)
 951 {
 952         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 953         OM_uint32 maj_stat, min_stat;
 954         gss_buffer_desc input_token, output_token;
 955         int conf_state;
 956         gss_qop_t qop_state;
 957         DATA_BLOB in;
 958
 959         dump_data_pw("gensec_gssapi_unseal_packet: sig\n", sig->data, sig->length);
 960
 961         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 962
 963         memcpy(in.data, sig->data, sig->length);
 964         memcpy(in.data + sig->length, data, length);
 965
 966         input_token.length = in.length;
 967         input_token.value = in.data;
 968
 969         maj_stat = gss_unwrap(&min_stat,
 970                               gensec_gssapi_state->gssapi_context,
 971                               &input_token,
 972                               &output_token,
 973                               &conf_state,
 974                               &qop_state);
 975         if (GSS_ERROR(maj_stat)) {
 976                 DEBUG(1, ("gensec_gssapi_unseal_packet: GSS UnWrap failed: %s\n",
 977                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 978                 return NT_STATUS_ACCESS_DENIED;
 979         }
 980
 981         if (output_token.length != length) {
 982                 return NT_STATUS_INTERNAL_ERROR;
 983         }
 984
 985         memcpy(data, output_token.value, length);
 986
 987         gss_release_buffer(&min_stat, &output_token);
 988
 989         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 990             && !conf_state) {
 991                 return NT_STATUS_ACCESS_DENIED;
 992         }
 993         return NT_STATUS_OK;
 994 }
 995
 996 static NTSTATUS gensec_gssapi_sign_packet(struct gensec_security *gensec_security,
 997                                           TALLOC_CTX *mem_ctx,
 998                                           const uint8_t *data, size_t length,
 999                                           const uint8_t *whole_pdu, size_t pdu_length,
1000                                           DATA_BLOB *sig)
1001 {
1002         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
1003         OM_uint32 maj_stat, min_stat;
1004         gss_buffer_desc input_token, output_token;
1005         int conf_state;
1006         ssize_t sig_length = 0;
1007
1008         input_token.length = length;
1009         input_token.value = discard_const_p(uint8_t *, data);
1010
1011         maj_stat = gss_wrap(&min_stat,
1012                             gensec_gssapi_state->gssapi_context,
1013                             0,
1014                             GSS_C_QOP_DEFAULT,
1015                             &input_token,
1016                             &conf_state,
1017                             &output_token);
1018         if (GSS_ERROR(maj_stat)) {
1019                 DEBUG(1, ("GSS Wrap failed: %s\n",
1020                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
1021                 return NT_STATUS_ACCESS_DENIED;
1022         }
1023
1024         if (output_token.length < length) {
1025                 return NT_STATUS_INTERNAL_ERROR;
1026         }
1027
1028         sig_length = gensec_gssapi_sig_size(gensec_security, length);
1029
1030         /* Caller must pad to right boundary */
1031         if (output_token.length != (length + sig_length)) {
1032                 DEBUG(1, ("gensec_gssapi_sign_packet: GSS Wrap length [%ld] does not match caller length [%ld] plus sig size [%ld] = [%ld]\n",
1033                           (long)output_token.length, (long)length, (long)sig_length, (long)(length + sig_length)));
1034                 return NT_STATUS_INTERNAL_ERROR;
1035         }
1036
1037         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
1038
1039         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
1040
1041         gss_release_buffer(&min_stat, &output_token);
1042
1043         return NT_STATUS_OK;
1044 }
1045
1046 static NTSTATUS gensec_gssapi_check_packet(struct gensec_security *gensec_security,
1047                                            TALLOC_CTX *mem_ctx,
1048                                            const uint8_t *data, size_t length,
1049                                            const uint8_t *whole_pdu, size_t pdu_length,
1050                                            const DATA_BLOB *sig)
1051 {
1052         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
1053         OM_uint32 maj_stat, min_stat;
1054         gss_buffer_desc input_token, output_token;
1055         int conf_state;
1056         gss_qop_t qop_state;
1057         DATA_BLOB in;
1058
1059         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
1060
1061         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
1062
1063         memcpy(in.data, sig->data, sig->length);
1064         memcpy(in.data + sig->length, data, length);
1065
1066         input_token.length = in.length;
1067         input_token.value = in.data;
1068
1069         maj_stat = gss_unwrap(&min_stat,
1070                               gensec_gssapi_state->gssapi_context,
1071                               &input_token,
1072                               &output_token,
1073                               &conf_state,
1074                               &qop_state);
1075         if (GSS_ERROR(maj_stat)) {
1076                 DEBUG(1, ("GSS UnWrap failed: %s\n",
1077                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
1078                 return NT_STATUS_ACCESS_DENIED;
1079         }
1080
1081         if (output_token.length != length) {
1082                 return NT_STATUS_INTERNAL_ERROR;
1083         }
1084
1085         gss_release_buffer(&min_stat, &output_token);
1086
1087         return NT_STATUS_OK;
1088 }
1089
1090 /* Try to figure out what features we actually got on the connection */
1091 static BOOL gensec_gssapi_have_feature(struct gensec_security *gensec_security,
1092                                        uint32_t feature)
1093 {
1094         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
1095         if (feature & GENSEC_FEATURE_SIGN) {
1096                 /* If we are going GSSAPI SASL, then we honour the second negotiation */
1097                 if (gensec_gssapi_state->sasl
1098                     && gensec_gssapi_state->sasl_state == STAGE_DONE) {
1099                         return ((gensec_gssapi_state->sasl_protection & NEG_SIGN)
1100                                 && (gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG));
1101                 }
1102                 return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
1103         }
1104         if (feature & GENSEC_FEATURE_SEAL) {
1105                 /* If we are going GSSAPI SASL, then we honour the second negotiation */
1106                 if (gensec_gssapi_state->sasl
1107                     && gensec_gssapi_state->sasl_state == STAGE_DONE) {
1108                         return ((gensec_gssapi_state->sasl_protection & NEG_SEAL)
1109                                  && (gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG));
1110                 }
1111                 return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
1112         }
1113         if (feature & GENSEC_FEATURE_SESSION_KEY) {
1114                 /* Only for GSSAPI/Krb5 */
1115                 if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
1116                     && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements, gensec_gssapi_state->gss_oid->length) == 0)) {
1117                         return True;
1118                 }
1119         }
1120         if (feature & GENSEC_FEATURE_DCE_STYLE) {
1121                 return gensec_gssapi_state->got_flags & GSS_C_DCE_STYLE;
1122         }
1123         /* We can always do async (rather than strict request/reply) packets.  */
1124         if (feature & GENSEC_FEATURE_ASYNC_REPLIES) {
1125                 return True;
1126         }
1127         return False;
1128 }
1129
1130 /*
1131  * Extract the 'sesssion key' needed by SMB signing and ncacn_np
1132  * (for encrypting some passwords).
1133  *
1134  * This breaks all the abstractions, but what do you expect...
1135  */
1136 static NTSTATUS gensec_gssapi_session_key(struct gensec_security *gensec_security,
1137                                           DATA_BLOB *session_key)
1138 {
1139         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
1140
1141         if (gensec_gssapi_state->session_key.data) {
1142                 *session_key = gensec_gssapi_state->session_key;
1143                 return NT_STATUS_OK;
1144         }
1145
1146         /* Ensure we only call this for GSSAPI/krb5, otherwise things
1147          * could get very ugly */
1148         if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
1149             && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
1150                        gensec_gssapi_state->gss_oid->length) == 0)) {
1151                 OM_uint32 maj_stat, min_stat;
1152                 gss_buffer_desc skey;
1153
1154                 maj_stat = gsskrb5_get_initiator_subkey(&min_stat,
1155                                                         gensec_gssapi_state->gssapi_context,
1156                                                         &skey);
1157
1158                 if (maj_stat == 0) {
1159                         DEBUG(10, ("Got KRB5 session key of length %d\n",
1160                                    (int)skey.length));
1161                         gensec_gssapi_state->session_key = data_blob_talloc(gensec_gssapi_state,
1162                                                                             skey.value, skey.length);
1163                         *session_key = gensec_gssapi_state->session_key;
1164                         dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
1165
1166                         gss_release_buffer(&min_stat, &skey);
1167                         return NT_STATUS_OK;
1168                 }
1169                 return NT_STATUS_NO_USER_SESSION_KEY;
1170         }
1171
1172         DEBUG(1, ("NO session key for this mech\n"));
1173         return NT_STATUS_NO_USER_SESSION_KEY;
1174 }
1175
1176
1177 /* Get some basic (and authorization) information about the user on
1178  * this session.  This uses either the PAC (if present) or a local
1179  * database lookup */
1180 static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_security,
1181                                            struct auth_session_info **_session_info)
1182 {
1183         NTSTATUS nt_status;
1184         TALLOC_CTX *mem_ctx;
1185         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
1186         struct auth_serversupplied_info *server_info = NULL;
1187         struct auth_session_info *session_info = NULL;
1188         struct PAC_LOGON_INFO *logon_info;
1189         OM_uint32 maj_stat, min_stat;
1190         gss_buffer_desc name_token;
1191         gss_buffer_desc pac;
1192         krb5_keyblock *keyblock;
1193         time_t authtime;
1194         krb5_principal principal;
1195         char *principal_string;
1196         DATA_BLOB pac_blob;
1197
1198         if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
1199             || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
1200                        gensec_gssapi_state->gss_oid->length) != 0)) {
1201                 DEBUG(1, ("NO session info available for this mech\n"));
1202                 return NT_STATUS_INVALID_PARAMETER;
1203         }
1204
1205         mem_ctx = talloc_named(gensec_gssapi_state, 0, "gensec_gssapi_session_info context");
1206         NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
1207
1208         maj_stat = gss_display_name (&min_stat,
1209                                      gensec_gssapi_state->client_name,
1210                                      &name_token,
1211                                      NULL);
1212         if (maj_stat) {
1213                 talloc_free(mem_ctx);
1214                 return NT_STATUS_FOOBAR;
1215         }
1216
1217         principal_string = talloc_strndup(mem_ctx, name_token.value, name_token.length);
1218
1219         gss_release_buffer(&min_stat, &name_token);
1220
1221         if (!principal_string) {
1222                 talloc_free(mem_ctx);
1223                 return NT_STATUS_NO_MEMORY;
1224         }
1225
1226         maj_stat = gss_krb5_copy_service_keyblock(&min_stat,
1227                                                   gensec_gssapi_state->gssapi_context,
1228                                                   &keyblock);
1229
1230         if (maj_stat == 0) {
1231                 maj_stat = gsskrb5_extract_authtime_from_sec_context(&min_stat,
1232                                                                      gensec_gssapi_state->gssapi_context,
1233                                                                      &authtime);
1234         }
1235
1236         if (maj_stat == 0) {
1237                 maj_stat = gsskrb5_extract_authz_data_from_sec_context(&min_stat,
1238                                                                        gensec_gssapi_state->gssapi_context,
1239                                                                        KRB5_AUTHDATA_WIN2K_PAC,
1240                                                                        &pac);
1241         }
1242
1243         if (maj_stat == 0) {
1244                 pac_blob = data_blob_talloc(mem_ctx, pac.value, pac.length);
1245                 gss_release_buffer(&min_stat, &pac);
1246         }
1247
1248         /* IF we have the PAC - otherwise we need to get this
1249          * data from elsewere - local ldb, or (TODO) lookup of some
1250          * kind...
1251          */
1252         if (maj_stat == 0) {
1253                 krb5_error_code ret;
1254
1255                 ret = krb5_parse_name(gensec_gssapi_state->smb_krb5_context->krb5_context,
1256                                       principal_string, &principal);
1257                 if (ret) {
1258                         talloc_free(mem_ctx);
1259                         return NT_STATUS_INVALID_PARAMETER;
1260                 }
1261
1262                 /* decode and verify the pac */
1263                 nt_status = kerberos_pac_logon_info(mem_ctx, &logon_info, pac_blob,
1264                                                     gensec_gssapi_state->smb_krb5_context->krb5_context,
1265                                                     NULL, keyblock, principal, authtime, NULL);
1266                 krb5_free_principal(gensec_gssapi_state->smb_krb5_context->krb5_context, principal);
1267
1268                 if (NT_STATUS_IS_OK(nt_status)) {
1269                         union netr_Validation validation;
1270                         validation.sam3 = &logon_info->info3;
1271                         nt_status = make_server_info_netlogon_validation(gensec_gssapi_state,
1272                                                                          NULL,
1273                                                                          3, &validation,
1274                                                                          &server_info);
1275                         if (!NT_STATUS_IS_OK(nt_status)) {
1276                                 talloc_free(mem_ctx);
1277                                 return nt_status;
1278                         }
1279                 } else {
1280                         maj_stat = 1;
1281                 }
1282         }
1283
1284         if (maj_stat) {
1285                 DEBUG(1, ("Unable to use PAC, resorting to local user lookup!\n"));
1286                 nt_status = sam_get_server_info_principal(mem_ctx, principal_string,
1287                                                           &server_info);
1288
1289                 if (!NT_STATUS_IS_OK(nt_status)) {
1290                         talloc_free(mem_ctx);
1291                         return nt_status;
1292                 }
1293         }
1294
1295         /* references the server_info into the session_info */
1296         nt_status = auth_generate_session_info(mem_ctx, server_info, &session_info);
1297         if (!NT_STATUS_IS_OK(nt_status)) {
1298                 talloc_free(mem_ctx);
1299                 return nt_status;
1300         }
1301
1302         nt_status = gensec_gssapi_session_key(gensec_security, &session_info->session_key);
1303         if (!NT_STATUS_IS_OK(nt_status)) {
1304                 talloc_free(mem_ctx);
1305                 return nt_status;
1306         }
1307
1308         if (!(gensec_gssapi_state->got_flags & GSS_C_DELEG_FLAG)) {
1309                 DEBUG(10, ("gensec_gssapi: NO delegated credentials supplied by client\n"));
1310         } else {
1311                 krb5_error_code ret;
1312                 DEBUG(10, ("gensec_gssapi: delegated credentials supplied by client\n"));
1313                 session_info->credentials = cli_credentials_init(session_info);
1314                 if (!session_info->credentials) {
1315                         talloc_free(mem_ctx);
1316                         return NT_STATUS_NO_MEMORY;
1317                 }
1318
1319                 cli_credentials_set_conf(session_info->credentials);
1320
1321                 ret = cli_credentials_set_client_gss_creds(session_info->credentials,
1322                                                            gensec_gssapi_state->delegated_cred_handle,
1323                                                            CRED_SPECIFIED);
1324                 if (ret) {
1325                         talloc_free(mem_ctx);
1326                         return NT_STATUS_NO_MEMORY;
1327                 }
1328                 /* It has been taken from this place... */
1329                 gensec_gssapi_state->delegated_cred_handle = GSS_C_NO_CREDENTIAL;
1330         }
1331         talloc_steal(gensec_gssapi_state, session_info);
1332         talloc_free(mem_ctx);
1333         *_session_info = session_info;
1334
1335         return NT_STATUS_OK;
1336 }
1337
1338 static const char *gensec_gssapi_krb5_oids[] = {
1339         GENSEC_OID_KERBEROS5,
1340         GENSEC_OID_KERBEROS5_OLD,
1341         NULL
1342 };
1343
1344 /* As a server, this could in theory accept any GSSAPI mech */
1345 static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
1346         .name           = "gssapi_krb5",
1347         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
1348         .oid            = gensec_gssapi_krb5_oids,
1349         .client_start   = gensec_gssapi_client_start,
1350         .server_start   = gensec_gssapi_server_start,
1351         .magic          = gensec_gssapi_magic,
1352         .update         = gensec_gssapi_update,
1353         .session_key    = gensec_gssapi_session_key,
1354         .session_info   = gensec_gssapi_session_info,
1355         .sig_size       = gensec_gssapi_sig_size,
1356         .sign_packet    = gensec_gssapi_sign_packet,
1357         .check_packet   = gensec_gssapi_check_packet,
1358         .seal_packet    = gensec_gssapi_seal_packet,
1359         .unseal_packet  = gensec_gssapi_unseal_packet,
1360         .wrap           = gensec_gssapi_wrap,
1361         .unwrap         = gensec_gssapi_unwrap,
1362         .have_feature   = gensec_gssapi_have_feature,
1363         .enabled        = True,
1364         .kerberos       = True,
1365         .priority       = GENSEC_GSSAPI
1366 };
1367
1368 /* As a server, this could in theory accept any GSSAPI mech */
1369 static const struct gensec_security_ops gensec_gssapi_sasl_krb5_security_ops = {
1370         .name             = "gssapi_krb5_sasl",
1371         .sasl_name        = "GSSAPI",
1372         .client_start     = gensec_gssapi_sasl_client_start,
1373         .server_start     = gensec_gssapi_sasl_server_start,
1374         .update           = gensec_gssapi_update,
1375         .session_key      = gensec_gssapi_session_key,
1376         .session_info     = gensec_gssapi_session_info,
1377         .max_input_size   = gensec_gssapi_max_input_size,
1378         .max_wrapped_size = gensec_gssapi_max_wrapped_size,
1379         .wrap             = gensec_gssapi_wrap,
1380         .unwrap           = gensec_gssapi_unwrap,
1381         .have_feature     = gensec_gssapi_have_feature,
1382         .enabled          = True,
1383         .kerberos         = True,
1384         .priority         = GENSEC_GSSAPI
1385 };
1386
1387 NTSTATUS gensec_gssapi_init(void)
1388 {
1389         NTSTATUS ret;
1390
1391         ret = gensec_register(&gensec_gssapi_krb5_security_ops);
1392         if (!NT_STATUS_IS_OK(ret)) {
1393                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1394                         gensec_gssapi_krb5_security_ops.name));
1395                 return ret;
1396         }
1397
1398         ret = gensec_register(&gensec_gssapi_sasl_krb5_security_ops);
1399         if (!NT_STATUS_IS_OK(ret)) {
1400                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1401                         gensec_gssapi_sasl_krb5_security_ops.name));
1402                 return ret;
1403         }
1404
1405         return ret;
1406 }