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 "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_destructor(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_destructor);
 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_C_NULL_OID;
 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         /* don't do DNS lookups of any kind, it might/will fail for a netbios name */
 221         ret = gsskrb5_set_dns_canonicalize(lp_parm_bool(-1, "krb5", "set_dns_canonicalize", false));
 222         if (ret) {
 223                 DEBUG(1,("gensec_krb5_start: gsskrb5_set_dns_canonicalize failed\n"));
 224                 talloc_free(gensec_gssapi_state);
 225                 return NT_STATUS_INTERNAL_ERROR;
 226         }
 227
 228         ret = smb_krb5_init_context(gensec_gssapi_state,
 229                                     &gensec_gssapi_state->smb_krb5_context);
 230         if (ret) {
 231                 DEBUG(1,("gensec_krb5_start: krb5_init_context failed (%s)\n",
 232                          error_message(ret)));
 233                 talloc_free(gensec_gssapi_state);
 234                 return NT_STATUS_INTERNAL_ERROR;
 235         }
 236         return NT_STATUS_OK;
 237 }
 238
 239 static NTSTATUS gensec_gssapi_server_start(struct gensec_security *gensec_security)
 240 {
 241         NTSTATUS nt_status;
 242         int ret;
 243         struct gensec_gssapi_state *gensec_gssapi_state;
 244         struct cli_credentials *machine_account;
 245         struct gssapi_creds_container *gcc;
 246
 247         nt_status = gensec_gssapi_start(gensec_security);
 248         if (!NT_STATUS_IS_OK(nt_status)) {
 249                 return nt_status;
 250         }
 251
 252         gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 253
 254         machine_account = gensec_get_credentials(gensec_security);
 255
 256         if (!machine_account) {
 257                 DEBUG(3, ("No machine account credentials specified\n"));
 258                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 259         } else {
 260                 ret = cli_credentials_get_server_gss_creds(machine_account, &gcc);
 261                 if (ret) {
 262                         DEBUG(1, ("Aquiring acceptor credentials failed: %s\n",
 263                                   error_message(ret)));
 264                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 265                 }
 266         }
 267
 268         gensec_gssapi_state->server_cred = gcc;
 269         return NT_STATUS_OK;
 270
 271 }
 272
 273 static NTSTATUS gensec_gssapi_sasl_server_start(struct gensec_security *gensec_security)
 274 {
 275         NTSTATUS nt_status;
 276         struct gensec_gssapi_state *gensec_gssapi_state;
 277         nt_status = gensec_gssapi_server_start(gensec_security);
 278
 279         if (NT_STATUS_IS_OK(nt_status)) {
 280                 gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 281                 gensec_gssapi_state->sasl = True;
 282         }
 283         return nt_status;
 284 }
 285
 286 static NTSTATUS gensec_gssapi_client_start(struct gensec_security *gensec_security)
 287 {
 288         struct gensec_gssapi_state *gensec_gssapi_state;
 289         struct cli_credentials *creds = gensec_get_credentials(gensec_security);
 290         krb5_error_code ret;
 291         NTSTATUS nt_status;
 292         gss_buffer_desc name_token;
 293         gss_OID name_type;
 294         OM_uint32 maj_stat, min_stat;
 295         const char *hostname = gensec_get_target_hostname(gensec_security);
 296         const char *principal;
 297         struct gssapi_creds_container *gcc;
 298
 299         if (!hostname) {
 300                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 301                 return NT_STATUS_INVALID_PARAMETER;
 302         }
 303         if (is_ipaddress(hostname)) {
 304                 DEBUG(2, ("Cannot do GSSAPI to an IP address\n"));
 305                 return NT_STATUS_INVALID_PARAMETER;
 306         }
 307         if (strcmp(hostname, "localhost") == 0) {
 308                 DEBUG(2, ("GSSAPI to 'localhost' does not make sense\n"));
 309                 return NT_STATUS_INVALID_PARAMETER;
 310         }
 311
 312         nt_status = gensec_gssapi_start(gensec_security);
 313         if (!NT_STATUS_IS_OK(nt_status)) {
 314                 return nt_status;
 315         }
 316
 317         gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 318
 319         gensec_gssapi_state->gss_oid = gss_mech_krb5;
 320
 321         principal = gensec_get_target_principal(gensec_security);
 322         if (principal && lp_client_use_spnego_principal()) {
 323                 name_type = GSS_C_NULL_OID;
 324         } else {
 325                 principal = talloc_asprintf(gensec_gssapi_state, "%s@%s",
 326                                             gensec_get_target_service(gensec_security),
 327                                             hostname);
 328
 329                 name_type = GSS_C_NT_HOSTBASED_SERVICE;
 330         }
 331         name_token.value  = discard_const_p(uint8_t, principal);
 332         name_token.length = strlen(principal);
 333
 334
 335         maj_stat = gss_import_name (&min_stat,
 336                                     &name_token,
 337                                     name_type,
 338                                     &gensec_gssapi_state->server_name);
 339         if (maj_stat) {
 340                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 341                           (char *)name_token.value,
 342                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 343                 return NT_STATUS_INVALID_PARAMETER;
 344         }
 345
 346         ret = cli_credentials_get_client_gss_creds(creds, &gcc);
 347         switch (ret) {
 348         case 0:
 349                 break;
 350         case KRB5KDC_ERR_PREAUTH_FAILED:
 351                 return NT_STATUS_LOGON_FAILURE;
 352         case KRB5_KDC_UNREACH:
 353                 DEBUG(3, ("Cannot reach a KDC we require to contact %s\n", principal));
 354                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 355         default:
 356                 DEBUG(1, ("Aquiring initiator credentails failed\n"));
 357                 return NT_STATUS_UNSUCCESSFUL;
 358         }
 359
 360         gensec_gssapi_state->client_cred = gcc;
 361
 362         return NT_STATUS_OK;
 363 }
 364
 365 static NTSTATUS gensec_gssapi_sasl_client_start(struct gensec_security *gensec_security)
 366 {
 367         NTSTATUS nt_status;
 368         struct gensec_gssapi_state *gensec_gssapi_state;
 369         nt_status = gensec_gssapi_client_start(gensec_security);
 370
 371         if (NT_STATUS_IS_OK(nt_status)) {
 372                 gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 373                 gensec_gssapi_state->sasl = True;
 374         }
 375         return nt_status;
 376 }
 377
 378
 379 /**
 380  * Check if the packet is one for this mechansim
 381  *
 382  * @param gensec_security GENSEC state
 383  * @param in The request, as a DATA_BLOB
 384  * @return Error, INVALID_PARAMETER if it's not a packet for us
 385  *                or NT_STATUS_OK if the packet is ok.
 386  */
 387
 388 static NTSTATUS gensec_gssapi_magic(struct gensec_security *gensec_security,
 389                                     const DATA_BLOB *in)
 390 {
 391         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 392                 return NT_STATUS_OK;
 393         } else {
 394                 return NT_STATUS_INVALID_PARAMETER;
 395         }
 396 }
 397
 398
 399 /**
 400  * Next state function for the GSSAPI GENSEC mechanism
 401  *
 402  * @param gensec_gssapi_state GSSAPI State
 403  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 404  * @param in The request, as a DATA_BLOB
 405  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 406  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 407  *                or NT_STATUS_OK if the user is authenticated.
 408  */
 409
 410 static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 411                                    TALLOC_CTX *out_mem_ctx,
 412                                    const DATA_BLOB in, DATA_BLOB *out)
 413 {
 414         struct gensec_gssapi_state *gensec_gssapi_state
 415                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 416         NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
 417         OM_uint32 maj_stat, min_stat;
 418         OM_uint32 min_stat2;
 419         gss_buffer_desc input_token, output_token;
 420         gss_OID gss_oid_p = NULL;
 421         input_token.length = in.length;
 422         input_token.value = in.data;
 423
 424         switch (gensec_gssapi_state->sasl_state) {
 425         case STAGE_GSS_NEG:
 426         {
 427                 switch (gensec_security->gensec_role) {
 428                 case GENSEC_CLIENT:
 429                 {
 430                         maj_stat = gss_init_sec_context(&min_stat,
 431                                                         gensec_gssapi_state->client_cred->creds,
 432                                                         &gensec_gssapi_state->gssapi_context,
 433                                                         gensec_gssapi_state->server_name,
 434                                                         discard_const_p(gss_OID_desc, gensec_gssapi_state->gss_oid),
 435                                                         gensec_gssapi_state->want_flags,
 436                                                         0,
 437                                                         gensec_gssapi_state->input_chan_bindings,
 438                                                         &input_token,
 439                                                         &gss_oid_p,
 440                                                         &output_token,
 441                                                         &gensec_gssapi_state->got_flags, /* ret flags */
 442                                                         NULL);
 443                         if (gss_oid_p) {
 444                                 gensec_gssapi_state->gss_oid = gss_oid_p;
 445                         }
 446                         break;
 447                 }
 448                 case GENSEC_SERVER:
 449                 {
 450                         maj_stat = gss_accept_sec_context(&min_stat,
 451                                                           &gensec_gssapi_state->gssapi_context,
 452                                                           gensec_gssapi_state->server_cred->creds,
 453                                                           &input_token,
 454                                                           gensec_gssapi_state->input_chan_bindings,
 455                                                           &gensec_gssapi_state->client_name,
 456                                                           &gss_oid_p,
 457                                                           &output_token,
 458                                                           &gensec_gssapi_state->got_flags,
 459                                                           NULL,
 460                                                           &gensec_gssapi_state->delegated_cred_handle);
 461                         if (gss_oid_p) {
 462                                 gensec_gssapi_state->gss_oid = gss_oid_p;
 463                         }
 464                         break;
 465                 }
 466                 default:
 467                         return NT_STATUS_INVALID_PARAMETER;
 468
 469                 }
 470
 471                 gensec_gssapi_state->gss_exchange_count++;
 472
 473                 if (maj_stat == GSS_S_COMPLETE) {
 474                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 475                         gss_release_buffer(&min_stat2, &output_token);
 476
 477                         if (gensec_gssapi_state->got_flags & GSS_C_DELEG_FLAG) {
 478                                 DEBUG(5, ("gensec_gssapi: credentials were delegated\n"));
 479                         } else {
 480                                 DEBUG(5, ("gensec_gssapi: NO credentials were delegated\n"));
 481                         }
 482
 483                         /* We may have been invoked as SASL, so there
 484                          * is more work to do */
 485                         if (gensec_gssapi_state->sasl) {
 486                                 /* Due to a very subtle interaction
 487                                  * with SASL and the LDAP libs, we
 488                                  * must ensure the data pointer is
 489                                  * != NULL, but the length is 0.
 490                                  *
 491                                  * This ensures we send a 'zero
 492                                  * length' (rather than NULL) response
 493                                  */
 494
 495                                 if (!out->data) {
 496                                         out->data = (uint8_t *)talloc_strdup(out_mem_ctx, "\0");
 497                                 }
 498
 499                                 gensec_gssapi_state->sasl_state = STAGE_SASL_SSF_NEG;
 500                                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 501                         } else {
 502                                 gensec_gssapi_state->sasl_state = STAGE_DONE;
 503
 504                                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 505                                         DEBUG(5, ("GSSAPI Connection will be cryptographicly sealed\n"));
 506                                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 507                                         DEBUG(5, ("GSSAPI Connection will be cryptographicly signed\n"));
 508                                 } else {
 509                                         DEBUG(5, ("GSSAPI Connection will have no cryptographic protection\n"));
 510                                 }
 511
 512                                 return NT_STATUS_OK;
 513                         }
 514                 } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 515                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 516                         gss_release_buffer(&min_stat2, &output_token);
 517
 518                         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 519                 } else if (gss_oid_equal(gensec_gssapi_state->gss_oid, gss_mech_krb5)) {
 520                         switch (min_stat) {
 521                         case KRB5_KDC_UNREACH:
 522                                 DEBUG(3, ("Cannot reach a KDC we require: %s\n",
 523                                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 524                                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 525                         case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 526                                 DEBUG(3, ("Server is not registered with our KDC: %s\n",
 527                                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 528                                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 529                         case KRB5KRB_AP_ERR_MSG_TYPE:
 530                                 /* garbage input, possibly from the auto-mech detection */
 531                                 return NT_STATUS_INVALID_PARAMETER;
 532                         default:
 533                                 DEBUG(1, ("GSS Update(krb5)(%d) Update failed: %s\n",
 534                                           gensec_gssapi_state->gss_exchange_count,
 535                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 536                                 return nt_status;
 537                         }
 538                 } else {
 539                         DEBUG(1, ("GSS Update(%d) failed: %s\n",
 540                                   gensec_gssapi_state->gss_exchange_count,
 541                                   gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 542                         return nt_status;
 543                 }
 544                 break;
 545         }
 546
 547         /* These last two stages are only done if we were invoked as SASL */
 548         case STAGE_SASL_SSF_NEG:
 549         {
 550                 switch (gensec_security->gensec_role) {
 551                 case GENSEC_CLIENT:
 552                 {
 553                         uint8_t maxlength_proposed[4];
 554                         uint8_t maxlength_accepted[4];
 555                         uint8_t security_supported;
 556                         int conf_state;
 557                         gss_qop_t qop_state;
 558                         input_token.length = in.length;
 559                         input_token.value = in.data;
 560
 561                         /* As a client, we have just send a
 562                          * zero-length blob to the server (after the
 563                          * normal GSSAPI exchange), and it has replied
 564                          * with it's SASL negotiation */
 565
 566                         maj_stat = gss_unwrap(&min_stat,
 567                                               gensec_gssapi_state->gssapi_context,
 568                                               &input_token,
 569                                               &output_token,
 570                                               &conf_state,
 571                                               &qop_state);
 572                         if (GSS_ERROR(maj_stat)) {
 573                                 DEBUG(1, ("gensec_gssapi_update: GSS UnWrap of SASL protection negotiation failed: %s\n",
 574                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 575                                 return NT_STATUS_ACCESS_DENIED;
 576                         }
 577
 578                         if (output_token.length < 4) {
 579                                 return NT_STATUS_INVALID_PARAMETER;
 580                         }
 581
 582                         memcpy(maxlength_proposed, output_token.value, 4);
 583                         gss_release_buffer(&min_stat, &output_token);
 584
 585                         /* first byte is the proposed security */
 586                         security_supported = maxlength_proposed[0];
 587                         maxlength_proposed[0] = '\0';
 588
 589                         /* Rest is the proposed max wrap length */
 590                         gensec_gssapi_state->max_wrap_buf_size = MIN(RIVAL(maxlength_proposed, 0),
 591                                                                      gensec_gssapi_state->max_wrap_buf_size);
 592                         gensec_gssapi_state->sasl_protection = 0;
 593                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 594                                 if (security_supported & NEG_SEAL) {
 595                                         gensec_gssapi_state->sasl_protection |= NEG_SEAL;
 596                                 }
 597                         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 598                                 if (security_supported & NEG_SIGN) {
 599                                         gensec_gssapi_state->sasl_protection |= NEG_SIGN;
 600                                 }
 601                         } else if (security_supported & NEG_NONE) {
 602                                 gensec_gssapi_state->sasl_protection |= NEG_NONE;
 603                         } else {
 604                                 DEBUG(1, ("Remote server does not support unprotected connections"));
 605                                 return NT_STATUS_ACCESS_DENIED;
 606                         }
 607
 608                         /* Send back the negotiated max length */
 609
 610                         RSIVAL(maxlength_accepted, 0, gensec_gssapi_state->max_wrap_buf_size);
 611
 612                         maxlength_accepted[0] = gensec_gssapi_state->sasl_protection;
 613
 614                         input_token.value = maxlength_accepted;
 615                         input_token.length = sizeof(maxlength_accepted);
 616
 617                         maj_stat = gss_wrap(&min_stat,
 618                                             gensec_gssapi_state->gssapi_context,
 619                                             False,
 620                                             GSS_C_QOP_DEFAULT,
 621                                             &input_token,
 622                                             &conf_state,
 623                                             &output_token);
 624                         if (GSS_ERROR(maj_stat)) {
 625                                 DEBUG(1, ("GSS Update(SSF_NEG): GSS Wrap failed: %s\n",
 626                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 627                                 return NT_STATUS_ACCESS_DENIED;
 628                         }
 629
 630                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 631                         gss_release_buffer(&min_stat, &output_token);
 632
 633                         /* quirk:  This changes the value that gensec_have_feature returns, to be that after SASL negotiation */
 634                         gensec_gssapi_state->sasl_state = STAGE_DONE;
 635
 636                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 637                                 DEBUG(3, ("SASL/GSSAPI Connection to server will be cryptographicly sealed\n"));
 638                         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 639                                 DEBUG(3, ("SASL/GSSAPI Connection to server will be cryptographicly signed\n"));
 640                         } else {
 641                                 DEBUG(3, ("SASL/GSSAPI Connection to server will have no cryptographicly protection\n"));
 642                         }
 643
 644                         return NT_STATUS_OK;
 645                 }
 646                 case GENSEC_SERVER:
 647                 {
 648                         uint8_t maxlength_proposed[4];
 649                         uint8_t security_supported = 0x0;
 650                         int conf_state;
 651
 652                         /* As a server, we have just been sent a zero-length blob (note this, but it isn't fatal) */
 653                         if (in.length != 0) {
 654                                 DEBUG(1, ("SASL/GSSAPI: client sent non-zero length starting SASL negotiation!\n"));
 655                         }
 656
 657                         /* Give the client some idea what we will support */
 658
 659                         RSIVAL(maxlength_proposed, 0, gensec_gssapi_state->max_wrap_buf_size);
 660                         /* first byte is the proposed security */
 661                         maxlength_proposed[0] = '\0';
 662
 663                         gensec_gssapi_state->sasl_protection = 0;
 664                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 665                                 security_supported |= NEG_SEAL;
 666                         }
 667                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 668                                 security_supported |= NEG_SIGN;
 669                         }
 670                         if (security_supported == 0) {
 671                                 /* If we don't support anything, this must be 0 */
 672                                 RSIVAL(maxlength_proposed, 0, 0x0);
 673                         }
 674
 675                         /* TODO:  We may not wish to support this */
 676                         security_supported |= NEG_NONE;
 677                         maxlength_proposed[0] = security_supported;
 678
 679                         input_token.value = maxlength_proposed;
 680                         input_token.length = sizeof(maxlength_proposed);
 681
 682                         maj_stat = gss_wrap(&min_stat,
 683                                             gensec_gssapi_state->gssapi_context,
 684                                             False,
 685                                             GSS_C_QOP_DEFAULT,
 686                                             &input_token,
 687                                             &conf_state,
 688                                             &output_token);
 689                         if (GSS_ERROR(maj_stat)) {
 690                                 DEBUG(1, ("GSS Update(SSF_NEG): GSS Wrap failed: %s\n",
 691                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 692                                 return NT_STATUS_ACCESS_DENIED;
 693                         }
 694
 695                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 696                         gss_release_buffer(&min_stat, &output_token);
 697
 698                         gensec_gssapi_state->sasl_state = STAGE_SASL_SSF_ACCEPT;
 699                         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 700                 }
 701                 default:
 702                         return NT_STATUS_INVALID_PARAMETER;
 703
 704                 }
 705         }
 706         /* This is s server-only stage */
 707         case STAGE_SASL_SSF_ACCEPT:
 708         {
 709                 uint8_t maxlength_accepted[4];
 710                 uint8_t security_accepted;
 711                 int conf_state;
 712                 gss_qop_t qop_state;
 713                 input_token.length = in.length;
 714                 input_token.value = in.data;
 715
 716                 maj_stat = gss_unwrap(&min_stat,
 717                                       gensec_gssapi_state->gssapi_context,
 718                                       &input_token,
 719                                       &output_token,
 720                                       &conf_state,
 721                                       &qop_state);
 722                 if (GSS_ERROR(maj_stat)) {
 723                         DEBUG(1, ("gensec_gssapi_update: GSS UnWrap of SASL protection negotiation failed: %s\n",
 724                                   gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 725                         return NT_STATUS_ACCESS_DENIED;
 726                 }
 727
 728                 if (output_token.length < 4) {
 729                         return NT_STATUS_INVALID_PARAMETER;
 730                 }
 731
 732                 memcpy(maxlength_accepted, output_token.value, 4);
 733                 gss_release_buffer(&min_stat, &output_token);
 734
 735                 /* first byte is the proposed security */
 736                 security_accepted = maxlength_accepted[0];
 737                 maxlength_accepted[0] = '\0';
 738
 739                 /* Rest is the proposed max wrap length */
 740                 gensec_gssapi_state->max_wrap_buf_size = MIN(RIVAL(maxlength_accepted, 0),
 741                                                              gensec_gssapi_state->max_wrap_buf_size);
 742
 743                 gensec_gssapi_state->sasl_protection = 0;
 744                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 745                         if (security_accepted & NEG_SEAL) {
 746                                 gensec_gssapi_state->sasl_protection |= NEG_SEAL;
 747                         }
 748                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 749                         if (security_accepted & NEG_SIGN) {
 750                                 gensec_gssapi_state->sasl_protection |= NEG_SIGN;
 751                         }
 752                 } else if (security_accepted & NEG_NONE) {
 753                         gensec_gssapi_state->sasl_protection |= NEG_NONE;
 754                 } else {
 755                         DEBUG(1, ("Remote client does not support unprotected connections, but we failed to negotiate anything better"));
 756                         return NT_STATUS_ACCESS_DENIED;
 757                 }
 758
 759                 /* quirk:  This changes the value that gensec_have_feature returns, to be that after SASL negotiation */
 760                 gensec_gssapi_state->sasl_state = STAGE_DONE;
 761                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 762                         DEBUG(5, ("SASL/GSSAPI Connection from client will be cryptographicly sealed\n"));
 763                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 764                         DEBUG(5, ("SASL/GSSAPI Connection from client will be cryptographicly signed\n"));
 765                 } else {
 766                         DEBUG(5, ("SASL/GSSAPI Connection from client will have no cryptographic protection\n"));
 767                 }
 768
 769                 *out = data_blob(NULL, 0);
 770                 return NT_STATUS_OK;
 771         }
 772         default:
 773                 return NT_STATUS_INVALID_PARAMETER;
 774         }
 775 }
 776
 777 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 778                                    TALLOC_CTX *mem_ctx,
 779                                    const DATA_BLOB *in,
 780                                    DATA_BLOB *out)
 781 {
 782         struct gensec_gssapi_state *gensec_gssapi_state
 783                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 784         OM_uint32 maj_stat, min_stat;
 785         gss_buffer_desc input_token, output_token;
 786         int conf_state;
 787         input_token.length = in->length;
 788         input_token.value = in->data;
 789
 790         maj_stat = gss_wrap(&min_stat,
 791                             gensec_gssapi_state->gssapi_context,
 792                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 793                             GSS_C_QOP_DEFAULT,
 794                             &input_token,
 795                             &conf_state,
 796                             &output_token);
 797         if (GSS_ERROR(maj_stat)) {
 798                 DEBUG(1, ("gensec_gssapi_wrap: GSS Wrap failed: %s\n",
 799                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 800                 return NT_STATUS_ACCESS_DENIED;
 801         }
 802
 803         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 804         gss_release_buffer(&min_stat, &output_token);
 805
 806         if (gensec_gssapi_state->sasl) {
 807                 size_t max_wrapped_size = gensec_gssapi_max_wrapped_size(gensec_security);
 808                 if (max_wrapped_size < out->length) {
 809                         DEBUG(1, ("gensec_gssapi_wrap: when wrapped, INPUT data (%u) is grew to be larger than SASL negotiated maximum output size (%u > %u)\n",
 810                                   (unsigned)in->length,
 811                                   (unsigned)out->length,
 812                                   (unsigned int)max_wrapped_size));
 813                         return NT_STATUS_INVALID_PARAMETER;
 814                 }
 815         }
 816
 817         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 818             && !conf_state) {
 819                 return NT_STATUS_ACCESS_DENIED;
 820         }
 821         return NT_STATUS_OK;
 822 }
 823
 824 static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 825                                      TALLOC_CTX *mem_ctx,
 826                                      const DATA_BLOB *in,
 827                                      DATA_BLOB *out)
 828 {
 829         struct gensec_gssapi_state *gensec_gssapi_state
 830                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 831         OM_uint32 maj_stat, min_stat;
 832         gss_buffer_desc input_token, output_token;
 833         int conf_state;
 834         gss_qop_t qop_state;
 835         input_token.length = in->length;
 836         input_token.value = in->data;
 837
 838         if (gensec_gssapi_state->sasl) {
 839                 size_t max_wrapped_size = gensec_gssapi_max_wrapped_size(gensec_security);
 840                 if (max_wrapped_size < in->length) {
 841                         DEBUG(1, ("gensec_gssapi_unwrap: WRAPPED data is larger than SASL negotiated maximum size\n"));
 842                         return NT_STATUS_INVALID_PARAMETER;
 843                 }
 844         }
 845
 846         maj_stat = gss_unwrap(&min_stat,
 847                               gensec_gssapi_state->gssapi_context,
 848                               &input_token,
 849                               &output_token,
 850                               &conf_state,
 851                               &qop_state);
 852         if (GSS_ERROR(maj_stat)) {
 853                 DEBUG(1, ("gensec_gssapi_unwrap: GSS UnWrap failed: %s\n",
 854                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 855                 return NT_STATUS_ACCESS_DENIED;
 856         }
 857
 858         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 859         gss_release_buffer(&min_stat, &output_token);
 860
 861         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 862             && !conf_state) {
 863                 return NT_STATUS_ACCESS_DENIED;
 864         }
 865         return NT_STATUS_OK;
 866 }
 867
 868 /* Find out the maximum input size negotiated on this connection */
 869
 870 static size_t gensec_gssapi_max_input_size(struct gensec_security *gensec_security)
 871 {
 872         struct gensec_gssapi_state *gensec_gssapi_state
 873                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 874         OM_uint32 maj_stat, min_stat;
 875         OM_uint32 max_input_size;
 876
 877         maj_stat = gss_wrap_size_limit(&min_stat,
 878                                        gensec_gssapi_state->gssapi_context,
 879                                        gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 880                                        GSS_C_QOP_DEFAULT,
 881                                        gensec_gssapi_state->max_wrap_buf_size,
 882                                        &max_input_size);
 883         if (GSS_ERROR(maj_stat)) {
 884                 TALLOC_CTX *mem_ctx = talloc_new(NULL);
 885                 DEBUG(1, ("gensec_gssapi_max_input_size: determinaing signature size with gss_wrap_size_limit failed: %s\n",
 886                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 887                 talloc_free(mem_ctx);
 888                 return 0;
 889         }
 890
 891         return max_input_size;
 892 }
 893
 894 /* Find out the maximum output size negotiated on this connection */
 895 static size_t gensec_gssapi_max_wrapped_size(struct gensec_security *gensec_security)
 896 {
 897         struct gensec_gssapi_state *gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);;
 898         return gensec_gssapi_state->max_wrap_buf_size;
 899 }
 900
 901 static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_security,
 902                                           TALLOC_CTX *mem_ctx,
 903                                           uint8_t *data, size_t length,
 904                                           const uint8_t *whole_pdu, size_t pdu_length,
 905                                           DATA_BLOB *sig)
 906 {
 907         struct gensec_gssapi_state *gensec_gssapi_state
 908                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 909         OM_uint32 maj_stat, min_stat;
 910         gss_buffer_desc input_token, output_token;
 911         int conf_state;
 912         ssize_t sig_length;
 913
 914         input_token.length = length;
 915         input_token.value = data;
 916
 917         maj_stat = gss_wrap(&min_stat,
 918                             gensec_gssapi_state->gssapi_context,
 919                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 920                             GSS_C_QOP_DEFAULT,
 921                             &input_token,
 922                             &conf_state,
 923                             &output_token);
 924         if (GSS_ERROR(maj_stat)) {
 925                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap failed: %s\n",
 926                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 927                 return NT_STATUS_ACCESS_DENIED;
 928         }
 929
 930         if (output_token.length < input_token.length) {
 931                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap length [%ld] *less* than caller length [%ld]\n",
 932                           (long)output_token.length, (long)length));
 933                 return NT_STATUS_INTERNAL_ERROR;
 934         }
 935         sig_length = output_token.length - input_token.length;
 936
 937         memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);
 938         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 939
 940         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 941         dump_data_pw("gensec_gssapi_seal_packet: clear\n", data, length);
 942         dump_data_pw("gensec_gssapi_seal_packet: sealed\n", ((uint8_t *)output_token.value) + sig_length, output_token.length - sig_length);
 943
 944         gss_release_buffer(&min_stat, &output_token);
 945
 946         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 947             && !conf_state) {
 948                 return NT_STATUS_ACCESS_DENIED;
 949         }
 950         return NT_STATUS_OK;
 951 }
 952
 953 static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_security,
 954                                             TALLOC_CTX *mem_ctx,
 955                                             uint8_t *data, size_t length,
 956                                             const uint8_t *whole_pdu, size_t pdu_length,
 957                                             const DATA_BLOB *sig)
 958 {
 959         struct gensec_gssapi_state *gensec_gssapi_state
 960                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 961         OM_uint32 maj_stat, min_stat;
 962         gss_buffer_desc input_token, output_token;
 963         int conf_state;
 964         gss_qop_t qop_state;
 965         DATA_BLOB in;
 966
 967         dump_data_pw("gensec_gssapi_unseal_packet: sig\n", sig->data, sig->length);
 968
 969         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 970
 971         memcpy(in.data, sig->data, sig->length);
 972         memcpy(in.data + sig->length, data, length);
 973
 974         input_token.length = in.length;
 975         input_token.value = in.data;
 976
 977         maj_stat = gss_unwrap(&min_stat,
 978                               gensec_gssapi_state->gssapi_context,
 979                               &input_token,
 980                               &output_token,
 981                               &conf_state,
 982                               &qop_state);
 983         if (GSS_ERROR(maj_stat)) {
 984                 DEBUG(1, ("gensec_gssapi_unseal_packet: GSS UnWrap failed: %s\n",
 985                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 986                 return NT_STATUS_ACCESS_DENIED;
 987         }
 988
 989         if (output_token.length != length) {
 990                 return NT_STATUS_INTERNAL_ERROR;
 991         }
 992
 993         memcpy(data, output_token.value, length);
 994
 995         gss_release_buffer(&min_stat, &output_token);
 996
 997         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 998             && !conf_state) {
 999                 return NT_STATUS_ACCESS_DENIED;
1000         }
1001         return NT_STATUS_OK;
1002 }
1003
1004 static NTSTATUS gensec_gssapi_sign_packet(struct gensec_security *gensec_security,
1005                                           TALLOC_CTX *mem_ctx,
1006                                           const uint8_t *data, size_t length,
1007                                           const uint8_t *whole_pdu, size_t pdu_length,
1008                                           DATA_BLOB *sig)
1009 {
1010         struct gensec_gssapi_state *gensec_gssapi_state
1011                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1012         OM_uint32 maj_stat, min_stat;
1013         gss_buffer_desc input_token, output_token;
1014         int conf_state;
1015         ssize_t sig_length = 0;
1016
1017         input_token.length = length;
1018         input_token.value = discard_const_p(uint8_t *, data);
1019
1020         maj_stat = gss_wrap(&min_stat,
1021                             gensec_gssapi_state->gssapi_context,
1022                             0,
1023                             GSS_C_QOP_DEFAULT,
1024                             &input_token,
1025                             &conf_state,
1026                             &output_token);
1027         if (GSS_ERROR(maj_stat)) {
1028                 DEBUG(1, ("GSS Wrap failed: %s\n",
1029                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1030                 return NT_STATUS_ACCESS_DENIED;
1031         }
1032
1033         if (output_token.length < input_token.length) {
1034                 DEBUG(1, ("gensec_gssapi_sign_packet: GSS Wrap length [%ld] *less* than caller length [%ld]\n",
1035                           (long)output_token.length, (long)length));
1036                 return NT_STATUS_INTERNAL_ERROR;
1037         }
1038
1039         /* Caller must pad to right boundary */
1040         sig_length = output_token.length - input_token.length;
1041
1042         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
1043
1044         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
1045
1046         gss_release_buffer(&min_stat, &output_token);
1047
1048         return NT_STATUS_OK;
1049 }
1050
1051 static NTSTATUS gensec_gssapi_check_packet(struct gensec_security *gensec_security,
1052                                            TALLOC_CTX *mem_ctx,
1053                                            const uint8_t *data, size_t length,
1054                                            const uint8_t *whole_pdu, size_t pdu_length,
1055                                            const DATA_BLOB *sig)
1056 {
1057         struct gensec_gssapi_state *gensec_gssapi_state
1058                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1059         OM_uint32 maj_stat, min_stat;
1060         gss_buffer_desc input_token, output_token;
1061         int conf_state;
1062         gss_qop_t qop_state;
1063         DATA_BLOB in;
1064
1065         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
1066
1067         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
1068
1069         memcpy(in.data, sig->data, sig->length);
1070         memcpy(in.data + sig->length, data, length);
1071
1072         input_token.length = in.length;
1073         input_token.value = in.data;
1074
1075         maj_stat = gss_unwrap(&min_stat,
1076                               gensec_gssapi_state->gssapi_context,
1077                               &input_token,
1078                               &output_token,
1079                               &conf_state,
1080                               &qop_state);
1081         if (GSS_ERROR(maj_stat)) {
1082                 DEBUG(1, ("GSS UnWrap failed: %s\n",
1083                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1084                 return NT_STATUS_ACCESS_DENIED;
1085         }
1086
1087         if (output_token.length != length) {
1088                 return NT_STATUS_INTERNAL_ERROR;
1089         }
1090
1091         gss_release_buffer(&min_stat, &output_token);
1092
1093         return NT_STATUS_OK;
1094 }
1095
1096 /* Try to figure out what features we actually got on the connection */
1097 static BOOL gensec_gssapi_have_feature(struct gensec_security *gensec_security,
1098                                        uint32_t feature)
1099 {
1100         struct gensec_gssapi_state *gensec_gssapi_state
1101                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1102         if (feature & GENSEC_FEATURE_SIGN) {
1103                 /* If we are going GSSAPI SASL, then we honour the second negotiation */
1104                 if (gensec_gssapi_state->sasl
1105                     && gensec_gssapi_state->sasl_state == STAGE_DONE) {
1106                         return ((gensec_gssapi_state->sasl_protection & NEG_SIGN)
1107                                 && (gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG));
1108                 }
1109                 return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
1110         }
1111         if (feature & GENSEC_FEATURE_SEAL) {
1112                 /* If we are going GSSAPI SASL, then we honour the second negotiation */
1113                 if (gensec_gssapi_state->sasl
1114                     && gensec_gssapi_state->sasl_state == STAGE_DONE) {
1115                         return ((gensec_gssapi_state->sasl_protection & NEG_SEAL)
1116                                  && (gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG));
1117                 }
1118                 return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
1119         }
1120         if (feature & GENSEC_FEATURE_SESSION_KEY) {
1121                 /* Only for GSSAPI/Krb5 */
1122                 if (gss_oid_equal(gensec_gssapi_state->gss_oid, gss_mech_krb5)) {
1123                         return True;
1124                 }
1125         }
1126         if (feature & GENSEC_FEATURE_DCE_STYLE) {
1127                 return gensec_gssapi_state->got_flags & GSS_C_DCE_STYLE;
1128         }
1129         /* We can always do async (rather than strict request/reply) packets.  */
1130         if (feature & GENSEC_FEATURE_ASYNC_REPLIES) {
1131                 return True;
1132         }
1133         return False;
1134 }
1135
1136 /*
1137  * Extract the 'sesssion key' needed by SMB signing and ncacn_np
1138  * (for encrypting some passwords).
1139  *
1140  * This breaks all the abstractions, but what do you expect...
1141  */
1142 static NTSTATUS gensec_gssapi_session_key(struct gensec_security *gensec_security,
1143                                           DATA_BLOB *session_key)
1144 {
1145         struct gensec_gssapi_state *gensec_gssapi_state
1146                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1147         OM_uint32 maj_stat, min_stat;
1148         krb5_keyblock *subkey;
1149
1150         if (gensec_gssapi_state->session_key.data) {
1151                 *session_key = gensec_gssapi_state->session_key;
1152                 return NT_STATUS_OK;
1153         }
1154
1155         maj_stat = gsskrb5_get_initiator_subkey(&min_stat,
1156                                                 gensec_gssapi_state->gssapi_context,
1157                                                 &subkey);
1158         if (maj_stat != 0) {
1159                 DEBUG(1, ("NO session key for this mech\n"));
1160                 return NT_STATUS_NO_USER_SESSION_KEY;
1161         }
1162
1163         DEBUG(10, ("Got KRB5 session key of length %d\n",
1164                    (int)KRB5_KEY_LENGTH(subkey)));
1165         gensec_gssapi_state->session_key = data_blob_talloc(gensec_gssapi_state,
1166                                                             KRB5_KEY_DATA(subkey), KRB5_KEY_LENGTH(subkey));
1167         krb5_free_keyblock(gensec_gssapi_state->smb_krb5_context->krb5_context, subkey);
1168         *session_key = gensec_gssapi_state->session_key;
1169         dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
1170
1171         return NT_STATUS_OK;
1172 }
1173
1174 /* Get some basic (and authorization) information about the user on
1175  * this session.  This uses either the PAC (if present) or a local
1176  * database lookup */
1177 static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_security,
1178                                            struct auth_session_info **_session_info)
1179 {
1180         NTSTATUS nt_status;
1181         TALLOC_CTX *mem_ctx;
1182         struct gensec_gssapi_state *gensec_gssapi_state
1183                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1184         struct auth_serversupplied_info *server_info = NULL;
1185         struct auth_session_info *session_info = NULL;
1186         struct PAC_LOGON_INFO *logon_info;
1187         OM_uint32 maj_stat, min_stat;
1188         gss_buffer_desc name_token;
1189         gss_buffer_desc pac;
1190         krb5_keyblock *keyblock;
1191         time_t authtime;
1192         krb5_principal principal;
1193         char *principal_string;
1194         DATA_BLOB pac_blob;
1195
1196         if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
1197             || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
1198                        gensec_gssapi_state->gss_oid->length) != 0)) {
1199                 DEBUG(1, ("NO session info available for this mech\n"));
1200                 return NT_STATUS_INVALID_PARAMETER;
1201         }
1202
1203         mem_ctx = talloc_named(gensec_gssapi_state, 0, "gensec_gssapi_session_info context");
1204         NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
1205
1206         maj_stat = gss_display_name (&min_stat,
1207                                      gensec_gssapi_state->client_name,
1208                                      &name_token,
1209                                      NULL);
1210         if (GSS_ERROR(maj_stat)) {
1211                 DEBUG(1, ("GSS display_name failed: %s\n",
1212                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
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 = gsskrb5_extract_authz_data_from_sec_context(&min_stat,
1227                                                                gensec_gssapi_state->gssapi_context,
1228                                                                KRB5_AUTHDATA_WIN2K_PAC,
1229                                                                &pac);
1230
1231
1232         if (maj_stat == 0) {
1233                 pac_blob = data_blob_talloc(mem_ctx, pac.value, pac.length);
1234                 gss_release_buffer(&min_stat, &pac);
1235
1236         } else {
1237                 pac_blob = data_blob(NULL, 0);
1238         }
1239
1240         /* IF we have the PAC - otherwise we need to get this
1241          * data from elsewere - local ldb, or (TODO) lookup of some
1242          * kind...
1243          */
1244         if (pac_blob.length) {
1245                 krb5_error_code ret;
1246                 union netr_Validation validation;
1247
1248                 maj_stat = gsskrb5_extract_authtime_from_sec_context(&min_stat,
1249                                                                      gensec_gssapi_state->gssapi_context,
1250                                                                      &authtime);
1251
1252                 if (GSS_ERROR(maj_stat)) {
1253                         DEBUG(1, ("gsskrb5_extract_authtime_from_sec_context: %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                 maj_stat = gsskrb5_extract_service_keyblock(&min_stat,
1260                                                             gensec_gssapi_state->gssapi_context,
1261                                                             &keyblock);
1262
1263                 if (GSS_ERROR(maj_stat)) {
1264                         DEBUG(1, ("gsskrb5_copy_service_keyblock failed: %s\n",
1265                                   gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1266                         talloc_free(mem_ctx);
1267                         return NT_STATUS_FOOBAR;
1268                 }
1269
1270                 ret = krb5_parse_name_flags(gensec_gssapi_state->smb_krb5_context->krb5_context,
1271                                             principal_string,
1272                                             KRB5_PRINCIPAL_PARSE_MUST_REALM,
1273                                             &principal);
1274                 if (ret) {
1275                         krb5_free_keyblock(gensec_gssapi_state->smb_krb5_context->krb5_context,
1276                                            keyblock);
1277                         talloc_free(mem_ctx);
1278                         return NT_STATUS_INVALID_PARAMETER;
1279                 }
1280
1281                 /* decode and verify the pac */
1282                 nt_status = kerberos_pac_logon_info(mem_ctx, &logon_info, pac_blob,
1283                                                     gensec_gssapi_state->smb_krb5_context->krb5_context,
1284                                                     NULL, keyblock, principal, authtime, NULL);
1285                 krb5_free_principal(gensec_gssapi_state->smb_krb5_context->krb5_context, principal);
1286                 krb5_free_keyblock(gensec_gssapi_state->smb_krb5_context->krb5_context,
1287                                    keyblock);
1288
1289                 if (!NT_STATUS_IS_OK(nt_status)) {
1290                         talloc_free(mem_ctx);
1291                         return nt_status;
1292                 }
1293                 validation.sam3 = &logon_info->info3;
1294                 nt_status = make_server_info_netlogon_validation(gensec_gssapi_state,
1295                                                                  NULL,
1296                                                                  3, &validation,
1297                                                                  &server_info);
1298                 if (!NT_STATUS_IS_OK(nt_status)) {
1299                         talloc_free(mem_ctx);
1300                         return nt_status;
1301                 }
1302         } else if (!lp_parm_bool(-1, "gensec", "require_pac", False)) {
1303                 DEBUG(1, ("Unable to find PAC, resorting to local user lookup: %s\n",
1304                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1305                 nt_status = sam_get_server_info_principal(mem_ctx, principal_string,
1306                                                           &server_info);
1307
1308                 if (!NT_STATUS_IS_OK(nt_status)) {
1309                         talloc_free(mem_ctx);
1310                         return nt_status;
1311                 }
1312         } else {
1313                 DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access: %s\n",
1314                           principal_string,
1315                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1316                 return NT_STATUS_ACCESS_DENIED;
1317         }
1318
1319         /* references the server_info into the session_info */
1320         nt_status = auth_generate_session_info(mem_ctx, server_info, &session_info);
1321         if (!NT_STATUS_IS_OK(nt_status)) {
1322                 talloc_free(mem_ctx);
1323                 return nt_status;
1324         }
1325
1326         nt_status = gensec_gssapi_session_key(gensec_security, &session_info->session_key);
1327         if (!NT_STATUS_IS_OK(nt_status)) {
1328                 talloc_free(mem_ctx);
1329                 return nt_status;
1330         }
1331
1332         if (!(gensec_gssapi_state->got_flags & GSS_C_DELEG_FLAG)) {
1333                 DEBUG(10, ("gensec_gssapi: NO delegated credentials supplied by client\n"));
1334         } else {
1335                 krb5_error_code ret;
1336                 DEBUG(10, ("gensec_gssapi: delegated credentials supplied by client\n"));
1337                 session_info->credentials = cli_credentials_init(session_info);
1338                 if (!session_info->credentials) {
1339                         talloc_free(mem_ctx);
1340                         return NT_STATUS_NO_MEMORY;
1341                 }
1342
1343                 cli_credentials_set_conf(session_info->credentials);
1344                 /* Just so we don't segfault trying to get at a username */
1345                 cli_credentials_set_anonymous(session_info->credentials);
1346
1347                 ret = cli_credentials_set_client_gss_creds(session_info->credentials,
1348                                                            gensec_gssapi_state->delegated_cred_handle,
1349                                                            CRED_SPECIFIED);
1350                 if (ret) {
1351                         talloc_free(mem_ctx);
1352                         return NT_STATUS_NO_MEMORY;
1353                 }
1354
1355                 /* This credential handle isn't useful for password authentication, so ensure nobody tries to do that */
1356                 cli_credentials_set_kerberos_state(session_info->credentials, CRED_MUST_USE_KERBEROS);
1357
1358                 /* It has been taken from this place... */
1359                 gensec_gssapi_state->delegated_cred_handle = GSS_C_NO_CREDENTIAL;
1360         }
1361         talloc_steal(gensec_gssapi_state, session_info);
1362         talloc_free(mem_ctx);
1363         *_session_info = session_info;
1364
1365         return NT_STATUS_OK;
1366 }
1367
1368 static const char *gensec_gssapi_krb5_oids[] = {
1369         GENSEC_OID_KERBEROS5_OLD,
1370         GENSEC_OID_KERBEROS5,
1371         NULL
1372 };
1373
1374 static const char *gensec_gssapi_spnego_oids[] = {
1375         GENSEC_OID_SPNEGO,
1376         NULL
1377 };
1378
1379 /* As a server, this could in theory accept any GSSAPI mech */
1380 static const struct gensec_security_ops gensec_gssapi_spnego_security_ops = {
1381         .name           = "gssapi_spnego",
1382         .sasl_name      = "GSS-SPNEGO",
1383         .auth_type      = DCERPC_AUTH_TYPE_SPNEGO,
1384         .oid            = gensec_gssapi_spnego_oids,
1385         .client_start   = gensec_gssapi_client_start,
1386         .server_start   = gensec_gssapi_server_start,
1387         .magic          = gensec_gssapi_magic,
1388         .update         = gensec_gssapi_update,
1389         .session_key    = gensec_gssapi_session_key,
1390         .session_info   = gensec_gssapi_session_info,
1391         .sign_packet    = gensec_gssapi_sign_packet,
1392         .check_packet   = gensec_gssapi_check_packet,
1393         .seal_packet    = gensec_gssapi_seal_packet,
1394         .unseal_packet  = gensec_gssapi_unseal_packet,
1395         .wrap           = gensec_gssapi_wrap,
1396         .unwrap         = gensec_gssapi_unwrap,
1397         .have_feature   = gensec_gssapi_have_feature,
1398         .enabled        = False,
1399         .kerberos       = True,
1400         .priority       = GENSEC_GSSAPI
1401 };
1402
1403 /* As a server, this could in theory accept any GSSAPI mech */
1404 static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
1405         .name           = "gssapi_krb5",
1406         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
1407         .oid            = gensec_gssapi_krb5_oids,
1408         .client_start   = gensec_gssapi_client_start,
1409         .server_start   = gensec_gssapi_server_start,
1410         .magic          = gensec_gssapi_magic,
1411         .update         = gensec_gssapi_update,
1412         .session_key    = gensec_gssapi_session_key,
1413         .session_info   = gensec_gssapi_session_info,
1414         .sign_packet    = gensec_gssapi_sign_packet,
1415         .check_packet   = gensec_gssapi_check_packet,
1416         .seal_packet    = gensec_gssapi_seal_packet,
1417         .unseal_packet  = gensec_gssapi_unseal_packet,
1418         .wrap           = gensec_gssapi_wrap,
1419         .unwrap         = gensec_gssapi_unwrap,
1420         .have_feature   = gensec_gssapi_have_feature,
1421         .enabled        = True,
1422         .kerberos       = True,
1423         .priority       = GENSEC_GSSAPI
1424 };
1425
1426 /* As a server, this could in theory accept any GSSAPI mech */
1427 static const struct gensec_security_ops gensec_gssapi_sasl_krb5_security_ops = {
1428         .name             = "gssapi_krb5_sasl",
1429         .sasl_name        = "GSSAPI",
1430         .client_start     = gensec_gssapi_sasl_client_start,
1431         .server_start     = gensec_gssapi_sasl_server_start,
1432         .update           = gensec_gssapi_update,
1433         .session_key      = gensec_gssapi_session_key,
1434         .session_info     = gensec_gssapi_session_info,
1435         .max_input_size   = gensec_gssapi_max_input_size,
1436         .max_wrapped_size = gensec_gssapi_max_wrapped_size,
1437         .wrap             = gensec_gssapi_wrap,
1438         .unwrap           = gensec_gssapi_unwrap,
1439         .have_feature     = gensec_gssapi_have_feature,
1440         .enabled          = True,
1441         .kerberos         = True,
1442         .priority         = GENSEC_GSSAPI
1443 };
1444
1445 NTSTATUS gensec_gssapi_init(void)
1446 {
1447         NTSTATUS ret;
1448
1449         ret = gensec_register(&gensec_gssapi_spnego_security_ops);
1450         if (!NT_STATUS_IS_OK(ret)) {
1451                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1452                         gensec_gssapi_spnego_security_ops.name));
1453                 return ret;
1454         }
1455
1456         ret = gensec_register(&gensec_gssapi_krb5_security_ops);
1457         if (!NT_STATUS_IS_OK(ret)) {
1458                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1459                         gensec_gssapi_krb5_security_ops.name));
1460                 return ret;
1461         }
1462
1463         ret = gensec_register(&gensec_gssapi_sasl_krb5_security_ops);
1464         if (!NT_STATUS_IS_OK(ret)) {
1465                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1466                         gensec_gssapi_sasl_krb5_security_ops.name));
1467                 return ret;
1468         }
1469
1470         return ret;
1471 }