source/auth/gensec/gensec_gssapi.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Kerberos backend for GENSEC
   5
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
   7    Copyright (C) Stefan Metzmacher <metze@samba.org> 2004-2005
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 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, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "includes.h"
  25 #include "lib/events/events.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 #include "param/param.h"
  38
  39 enum gensec_gssapi_sasl_state
  40 {
  41         STAGE_GSS_NEG,
  42         STAGE_SASL_SSF_NEG,
  43         STAGE_SASL_SSF_ACCEPT,
  44         STAGE_DONE
  45 };
  46
  47 #define NEG_SEAL 0x4
  48 #define NEG_SIGN 0x2
  49 #define NEG_NONE 0x1
  50
  51 struct gensec_gssapi_state {
  52         gss_ctx_id_t gssapi_context;
  53         struct gss_channel_bindings_struct *input_chan_bindings;
  54         gss_name_t server_name;
  55         gss_name_t client_name;
  56         OM_uint32 want_flags, got_flags;
  57         const gss_OID_desc *gss_oid;
  58
  59         DATA_BLOB session_key;
  60         DATA_BLOB pac;
  61
  62         struct smb_krb5_context *smb_krb5_context;
  63         struct gssapi_creds_container *client_cred;
  64         struct gssapi_creds_container *server_cred;
  65
  66         gss_cred_id_t delegated_cred_handle;
  67
  68         bool sasl; /* We have two different mechs in this file: One
  69                     * for SASL wrapped GSSAPI and another for normal
  70                     * GSSAPI */
  71         enum gensec_gssapi_sasl_state sasl_state;
  72         uint8_t sasl_protection; /* What was negotiated at the SASL
  73                                   * layer, independent of the GSSAPI
  74                                   * layer... */
  75
  76         size_t max_wrap_buf_size;
  77         int gss_exchange_count;
  78 };
  79
  80 static size_t gensec_gssapi_max_input_size(struct gensec_security *gensec_security);
  81 static size_t gensec_gssapi_max_wrapped_size(struct gensec_security *gensec_security);
  82
  83 static char *gssapi_error_string(TALLOC_CTX *mem_ctx,
  84                                  OM_uint32 maj_stat, OM_uint32 min_stat,
  85                                  const gss_OID_desc *mech)
  86 {
  87         OM_uint32 disp_min_stat, disp_maj_stat;
  88         gss_buffer_desc maj_error_message;
  89         gss_buffer_desc min_error_message;
  90         char *maj_error_string, *min_error_string;
  91         OM_uint32 msg_ctx = 0;
  92
  93         char *ret;
  94
  95         maj_error_message.value = NULL;
  96         min_error_message.value = NULL;
  97         maj_error_message.length = 0;
  98         min_error_message.length = 0;
  99
 100         disp_maj_stat = gss_display_status(&disp_min_stat, maj_stat, GSS_C_GSS_CODE,
 101                            mech, &msg_ctx, &maj_error_message);
 102         disp_maj_stat = gss_display_status(&disp_min_stat, min_stat, GSS_C_MECH_CODE,
 103                            mech, &msg_ctx, &min_error_message);
 104
 105         maj_error_string = talloc_strndup(mem_ctx, (char *)maj_error_message.value, maj_error_message.length);
 106
 107         min_error_string = talloc_strndup(mem_ctx, (char *)min_error_message.value, min_error_message.length);
 108
 109         ret = talloc_asprintf(mem_ctx, "%s: %s", maj_error_string, min_error_string);
 110
 111         talloc_free(maj_error_string);
 112         talloc_free(min_error_string);
 113
 114         gss_release_buffer(&disp_min_stat, &maj_error_message);
 115         gss_release_buffer(&disp_min_stat, &min_error_message);
 116
 117         return ret;
 118 }
 119
 120
 121 static int gensec_gssapi_destructor(struct gensec_gssapi_state *gensec_gssapi_state)
 122 {
 123         OM_uint32 maj_stat, min_stat;
 124
 125         if (gensec_gssapi_state->delegated_cred_handle != GSS_C_NO_CREDENTIAL) {
 126                 maj_stat = gss_release_cred(&min_stat,
 127                                             &gensec_gssapi_state->delegated_cred_handle);
 128         }
 129
 130         if (gensec_gssapi_state->gssapi_context != GSS_C_NO_CONTEXT) {
 131                 maj_stat = gss_delete_sec_context (&min_stat,
 132                                                    &gensec_gssapi_state->gssapi_context,
 133                                                    GSS_C_NO_BUFFER);
 134         }
 135
 136         if (gensec_gssapi_state->server_name != GSS_C_NO_NAME) {
 137                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->server_name);
 138         }
 139         if (gensec_gssapi_state->client_name != GSS_C_NO_NAME) {
 140                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->client_name);
 141         }
 142         return 0;
 143 }
 144
 145 static NTSTATUS gensec_gssapi_start(struct gensec_security *gensec_security)
 146 {
 147         struct gensec_gssapi_state *gensec_gssapi_state;
 148         krb5_error_code ret;
 149         struct gsskrb5_send_to_kdc send_to_kdc;
 150
 151         gensec_gssapi_state = talloc(gensec_security, struct gensec_gssapi_state);
 152         if (!gensec_gssapi_state) {
 153                 return NT_STATUS_NO_MEMORY;
 154         }
 155
 156         gensec_gssapi_state->gss_exchange_count = 0;
 157         gensec_gssapi_state->max_wrap_buf_size
 158                 = lp_parm_int(global_loadparm, NULL, "gensec_gssapi", "max wrap buf size", 65536);
 159
 160         gensec_gssapi_state->sasl = false;
 161         gensec_gssapi_state->sasl_state = STAGE_GSS_NEG;
 162
 163         gensec_security->private_data = gensec_gssapi_state;
 164
 165         gensec_gssapi_state->gssapi_context = GSS_C_NO_CONTEXT;
 166         gensec_gssapi_state->server_name = GSS_C_NO_NAME;
 167         gensec_gssapi_state->client_name = GSS_C_NO_NAME;
 168
 169         /* TODO: Fill in channel bindings */
 170         gensec_gssapi_state->input_chan_bindings = GSS_C_NO_CHANNEL_BINDINGS;
 171
 172         gensec_gssapi_state->want_flags = 0;
 173         if (lp_parm_bool(global_loadparm, NULL, "gensec_gssapi", "mutual", true)) {
 174                 gensec_gssapi_state->want_flags |= GSS_C_MUTUAL_FLAG;
 175         }
 176         if (lp_parm_bool(global_loadparm, NULL, "gensec_gssapi", "delegation", true)) {
 177                 gensec_gssapi_state->want_flags |= GSS_C_DELEG_FLAG;
 178         }
 179         if (lp_parm_bool(global_loadparm, NULL, "gensec_gssapi", "replay", true)) {
 180                 gensec_gssapi_state->want_flags |= GSS_C_REPLAY_FLAG;
 181         }
 182         if (lp_parm_bool(global_loadparm, NULL, "gensec_gssapi", "sequence", true)) {
 183                 gensec_gssapi_state->want_flags |= GSS_C_SEQUENCE_FLAG;
 184         }
 185
 186         gensec_gssapi_state->got_flags = 0;
 187
 188         gensec_gssapi_state->session_key = data_blob(NULL, 0);
 189         gensec_gssapi_state->pac = data_blob(NULL, 0);
 190
 191         gensec_gssapi_state->delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 192
 193         talloc_set_destructor(gensec_gssapi_state, gensec_gssapi_destructor);
 194
 195         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 196                 gensec_gssapi_state->want_flags |= GSS_C_INTEG_FLAG;
 197         }
 198         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 199                 gensec_gssapi_state->want_flags |= GSS_C_CONF_FLAG;
 200         }
 201         if (gensec_security->want_features & GENSEC_FEATURE_DCE_STYLE) {
 202                 gensec_gssapi_state->want_flags |= GSS_C_DCE_STYLE;
 203         }
 204
 205         gensec_gssapi_state->gss_oid = GSS_C_NULL_OID;
 206
 207         send_to_kdc.func = smb_krb5_send_and_recv_func;
 208         send_to_kdc.ptr = gensec_security->event_ctx;
 209
 210         ret = gsskrb5_set_send_to_kdc(&send_to_kdc);
 211         if (ret) {
 212                 DEBUG(1,("gensec_krb5_start: gsskrb5_set_send_to_kdc failed\n"));
 213                 talloc_free(gensec_gssapi_state);
 214                 return NT_STATUS_INTERNAL_ERROR;
 215         }
 216         if (lp_realm(global_loadparm) && *lp_realm(global_loadparm)) {
 217                 char *upper_realm = strupper_talloc(gensec_gssapi_state, lp_realm(global_loadparm));
 218                 if (!upper_realm) {
 219                         DEBUG(1,("gensec_krb5_start: could not uppercase realm: %s\n", lp_realm(global_loadparm)));
 220                         talloc_free(gensec_gssapi_state);
 221                         return NT_STATUS_NO_MEMORY;
 222                 }
 223                 ret = gsskrb5_set_default_realm(upper_realm);
 224                 talloc_free(upper_realm);
 225                 if (ret) {
 226                         DEBUG(1,("gensec_krb5_start: gsskrb5_set_default_realm failed\n"));
 227                         talloc_free(gensec_gssapi_state);
 228                         return NT_STATUS_INTERNAL_ERROR;
 229                 }
 230         }
 231
 232         /* don't do DNS lookups of any kind, it might/will fail for a netbios name */
 233         ret = gsskrb5_set_dns_canonicalize(lp_parm_bool(global_loadparm, NULL, "krb5", "set_dns_canonicalize", false));
 234         if (ret) {
 235                 DEBUG(1,("gensec_krb5_start: gsskrb5_set_dns_canonicalize failed\n"));
 236                 talloc_free(gensec_gssapi_state);
 237                 return NT_STATUS_INTERNAL_ERROR;
 238         }
 239
 240         ret = smb_krb5_init_context(gensec_gssapi_state,
 241                                     gensec_security->event_ctx,
 242                                     &gensec_gssapi_state->smb_krb5_context);
 243         if (ret) {
 244                 DEBUG(1,("gensec_krb5_start: krb5_init_context failed (%s)\n",
 245                          error_message(ret)));
 246                 talloc_free(gensec_gssapi_state);
 247                 return NT_STATUS_INTERNAL_ERROR;
 248         }
 249         return NT_STATUS_OK;
 250 }
 251
 252 static NTSTATUS gensec_gssapi_server_start(struct gensec_security *gensec_security)
 253 {
 254         NTSTATUS nt_status;
 255         int ret;
 256         struct gensec_gssapi_state *gensec_gssapi_state;
 257         struct cli_credentials *machine_account;
 258         struct gssapi_creds_container *gcc;
 259
 260         nt_status = gensec_gssapi_start(gensec_security);
 261         if (!NT_STATUS_IS_OK(nt_status)) {
 262                 return nt_status;
 263         }
 264
 265         gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 266
 267         machine_account = gensec_get_credentials(gensec_security);
 268
 269         if (!machine_account) {
 270                 DEBUG(3, ("No machine account credentials specified\n"));
 271                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 272         } else {
 273                 ret = cli_credentials_get_server_gss_creds(machine_account, &gcc);
 274                 if (ret) {
 275                         DEBUG(1, ("Aquiring acceptor credentials failed: %s\n",
 276                                   error_message(ret)));
 277                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 278                 }
 279         }
 280
 281         gensec_gssapi_state->server_cred = gcc;
 282         return NT_STATUS_OK;
 283
 284 }
 285
 286 static NTSTATUS gensec_gssapi_sasl_server_start(struct gensec_security *gensec_security)
 287 {
 288         NTSTATUS nt_status;
 289         struct gensec_gssapi_state *gensec_gssapi_state;
 290         nt_status = gensec_gssapi_server_start(gensec_security);
 291
 292         if (NT_STATUS_IS_OK(nt_status)) {
 293                 gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 294                 gensec_gssapi_state->sasl = true;
 295         }
 296         return nt_status;
 297 }
 298
 299 static NTSTATUS gensec_gssapi_client_start(struct gensec_security *gensec_security)
 300 {
 301         struct gensec_gssapi_state *gensec_gssapi_state;
 302         struct cli_credentials *creds = gensec_get_credentials(gensec_security);
 303         krb5_error_code ret;
 304         NTSTATUS nt_status;
 305         gss_buffer_desc name_token;
 306         gss_OID name_type;
 307         OM_uint32 maj_stat, min_stat;
 308         const char *hostname = gensec_get_target_hostname(gensec_security);
 309         const char *principal;
 310         struct gssapi_creds_container *gcc;
 311
 312         if (!hostname) {
 313                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 314                 return NT_STATUS_INVALID_PARAMETER;
 315         }
 316         if (is_ipaddress(hostname)) {
 317                 DEBUG(2, ("Cannot do GSSAPI to an IP address\n"));
 318                 return NT_STATUS_INVALID_PARAMETER;
 319         }
 320         if (strcmp(hostname, "localhost") == 0) {
 321                 DEBUG(2, ("GSSAPI to 'localhost' does not make sense\n"));
 322                 return NT_STATUS_INVALID_PARAMETER;
 323         }
 324
 325         nt_status = gensec_gssapi_start(gensec_security);
 326         if (!NT_STATUS_IS_OK(nt_status)) {
 327                 return nt_status;
 328         }
 329
 330         gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 331
 332         gensec_gssapi_state->gss_oid = gss_mech_krb5;
 333
 334         principal = gensec_get_target_principal(gensec_security);
 335         if (principal && lp_client_use_spnego_principal(global_loadparm)) {
 336                 name_type = GSS_C_NULL_OID;
 337         } else {
 338                 principal = talloc_asprintf(gensec_gssapi_state, "%s@%s",
 339                                             gensec_get_target_service(gensec_security),
 340                                             hostname);
 341
 342                 name_type = GSS_C_NT_HOSTBASED_SERVICE;
 343         }
 344         name_token.value  = discard_const_p(uint8_t, principal);
 345         name_token.length = strlen(principal);
 346
 347
 348         maj_stat = gss_import_name (&min_stat,
 349                                     &name_token,
 350                                     name_type,
 351                                     &gensec_gssapi_state->server_name);
 352         if (maj_stat) {
 353                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 354                           (char *)name_token.value,
 355                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 356                 return NT_STATUS_INVALID_PARAMETER;
 357         }
 358
 359         ret = cli_credentials_get_client_gss_creds(creds, &gcc);
 360         switch (ret) {
 361         case 0:
 362                 break;
 363         case KRB5KDC_ERR_PREAUTH_FAILED:
 364                 return NT_STATUS_LOGON_FAILURE;
 365         case KRB5_KDC_UNREACH:
 366                 DEBUG(3, ("Cannot reach a KDC we require to contact %s\n", principal));
 367                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 368         default:
 369                 DEBUG(1, ("Aquiring initiator credentails failed\n"));
 370                 return NT_STATUS_UNSUCCESSFUL;
 371         }
 372
 373         gensec_gssapi_state->client_cred = gcc;
 374         if (!talloc_reference(gensec_gssapi_state, gcc)) {
 375                 return NT_STATUS_NO_MEMORY;
 376         }
 377
 378         return NT_STATUS_OK;
 379 }
 380
 381 static NTSTATUS gensec_gssapi_sasl_client_start(struct gensec_security *gensec_security)
 382 {
 383         NTSTATUS nt_status;
 384         struct gensec_gssapi_state *gensec_gssapi_state;
 385         nt_status = gensec_gssapi_client_start(gensec_security);
 386
 387         if (NT_STATUS_IS_OK(nt_status)) {
 388                 gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 389                 gensec_gssapi_state->sasl = true;
 390         }
 391         return nt_status;
 392 }
 393
 394
 395 /**
 396  * Check if the packet is one for this mechansim
 397  *
 398  * @param gensec_security GENSEC state
 399  * @param in The request, as a DATA_BLOB
 400  * @return Error, INVALID_PARAMETER if it's not a packet for us
 401  *                or NT_STATUS_OK if the packet is ok.
 402  */
 403
 404 static NTSTATUS gensec_gssapi_magic(struct gensec_security *gensec_security,
 405                                     const DATA_BLOB *in)
 406 {
 407         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 408                 return NT_STATUS_OK;
 409         } else {
 410                 return NT_STATUS_INVALID_PARAMETER;
 411         }
 412 }
 413
 414
 415 /**
 416  * Next state function for the GSSAPI GENSEC mechanism
 417  *
 418  * @param gensec_gssapi_state GSSAPI State
 419  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 420  * @param in The request, as a DATA_BLOB
 421  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 422  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 423  *                or NT_STATUS_OK if the user is authenticated.
 424  */
 425
 426 static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 427                                    TALLOC_CTX *out_mem_ctx,
 428                                    const DATA_BLOB in, DATA_BLOB *out)
 429 {
 430         struct gensec_gssapi_state *gensec_gssapi_state
 431                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 432         NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
 433         OM_uint32 maj_stat, min_stat;
 434         OM_uint32 min_stat2;
 435         gss_buffer_desc input_token, output_token;
 436         gss_OID gss_oid_p = NULL;
 437         input_token.length = in.length;
 438         input_token.value = in.data;
 439
 440         switch (gensec_gssapi_state->sasl_state) {
 441         case STAGE_GSS_NEG:
 442         {
 443                 switch (gensec_security->gensec_role) {
 444                 case GENSEC_CLIENT:
 445                 {
 446                         maj_stat = gss_init_sec_context(&min_stat,
 447                                                         gensec_gssapi_state->client_cred->creds,
 448                                                         &gensec_gssapi_state->gssapi_context,
 449                                                         gensec_gssapi_state->server_name,
 450                                                         discard_const_p(gss_OID_desc, gensec_gssapi_state->gss_oid),
 451                                                         gensec_gssapi_state->want_flags,
 452                                                         0,
 453                                                         gensec_gssapi_state->input_chan_bindings,
 454                                                         &input_token,
 455                                                         &gss_oid_p,
 456                                                         &output_token,
 457                                                         &gensec_gssapi_state->got_flags, /* ret flags */
 458                                                         NULL);
 459                         if (gss_oid_p) {
 460                                 gensec_gssapi_state->gss_oid = gss_oid_p;
 461                         }
 462                         break;
 463                 }
 464                 case GENSEC_SERVER:
 465                 {
 466                         maj_stat = gss_accept_sec_context(&min_stat,
 467                                                           &gensec_gssapi_state->gssapi_context,
 468                                                           gensec_gssapi_state->server_cred->creds,
 469                                                           &input_token,
 470                                                           gensec_gssapi_state->input_chan_bindings,
 471                                                           &gensec_gssapi_state->client_name,
 472                                                           &gss_oid_p,
 473                                                           &output_token,
 474                                                           &gensec_gssapi_state->got_flags,
 475                                                           NULL,
 476                                                           &gensec_gssapi_state->delegated_cred_handle);
 477                         if (gss_oid_p) {
 478                                 gensec_gssapi_state->gss_oid = gss_oid_p;
 479                         }
 480                         break;
 481                 }
 482                 default:
 483                         return NT_STATUS_INVALID_PARAMETER;
 484
 485                 }
 486
 487                 gensec_gssapi_state->gss_exchange_count++;
 488
 489                 if (maj_stat == GSS_S_COMPLETE) {
 490                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 491                         gss_release_buffer(&min_stat2, &output_token);
 492
 493                         if (gensec_gssapi_state->got_flags & GSS_C_DELEG_FLAG) {
 494                                 DEBUG(5, ("gensec_gssapi: credentials were delegated\n"));
 495                         } else {
 496                                 DEBUG(5, ("gensec_gssapi: NO credentials were delegated\n"));
 497                         }
 498
 499                         /* We may have been invoked as SASL, so there
 500                          * is more work to do */
 501                         if (gensec_gssapi_state->sasl) {
 502                                 /* Due to a very subtle interaction
 503                                  * with SASL and the LDAP libs, we
 504                                  * must ensure the data pointer is
 505                                  * != NULL, but the length is 0.
 506                                  *
 507                                  * This ensures we send a 'zero
 508                                  * length' (rather than NULL) response
 509                                  */
 510
 511                                 if (!out->data) {
 512                                         out->data = (uint8_t *)talloc_strdup(out_mem_ctx, "\0");
 513                                 }
 514
 515                                 gensec_gssapi_state->sasl_state = STAGE_SASL_SSF_NEG;
 516                                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 517                         } else {
 518                                 gensec_gssapi_state->sasl_state = STAGE_DONE;
 519
 520                                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 521                                         DEBUG(5, ("GSSAPI Connection will be cryptographicly sealed\n"));
 522                                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 523                                         DEBUG(5, ("GSSAPI Connection will be cryptographicly signed\n"));
 524                                 } else {
 525                                         DEBUG(5, ("GSSAPI Connection will have no cryptographic protection\n"));
 526                                 }
 527
 528                                 return NT_STATUS_OK;
 529                         }
 530                 } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 531                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 532                         gss_release_buffer(&min_stat2, &output_token);
 533
 534                         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 535                 } else if (gss_oid_equal(gensec_gssapi_state->gss_oid, gss_mech_krb5)) {
 536                         switch (min_stat) {
 537                         case KRB5_KDC_UNREACH:
 538                                 DEBUG(3, ("Cannot reach a KDC we require: %s\n",
 539                                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 540                                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 541                         case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 542                                 DEBUG(3, ("Server is not registered with our KDC: %s\n",
 543                                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 544                                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 545                         case KRB5KRB_AP_ERR_MSG_TYPE:
 546                                 /* garbage input, possibly from the auto-mech detection */
 547                                 return NT_STATUS_INVALID_PARAMETER;
 548                         default:
 549                                 DEBUG(1, ("GSS Update(krb5)(%d) Update failed: %s\n",
 550                                           gensec_gssapi_state->gss_exchange_count,
 551                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 552                                 return nt_status;
 553                         }
 554                 } else {
 555                         DEBUG(1, ("GSS Update(%d) failed: %s\n",
 556                                   gensec_gssapi_state->gss_exchange_count,
 557                                   gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 558                         return nt_status;
 559                 }
 560                 break;
 561         }
 562
 563         /* These last two stages are only done if we were invoked as SASL */
 564         case STAGE_SASL_SSF_NEG:
 565         {
 566                 switch (gensec_security->gensec_role) {
 567                 case GENSEC_CLIENT:
 568                 {
 569                         uint8_t maxlength_proposed[4];
 570                         uint8_t maxlength_accepted[4];
 571                         uint8_t security_supported;
 572                         int conf_state;
 573                         gss_qop_t qop_state;
 574                         input_token.length = in.length;
 575                         input_token.value = in.data;
 576
 577                         /* As a client, we have just send a
 578                          * zero-length blob to the server (after the
 579                          * normal GSSAPI exchange), and it has replied
 580                          * with it's SASL negotiation */
 581
 582                         maj_stat = gss_unwrap(&min_stat,
 583                                               gensec_gssapi_state->gssapi_context,
 584                                               &input_token,
 585                                               &output_token,
 586                                               &conf_state,
 587                                               &qop_state);
 588                         if (GSS_ERROR(maj_stat)) {
 589                                 DEBUG(1, ("gensec_gssapi_update: GSS UnWrap of SASL protection negotiation failed: %s\n",
 590                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 591                                 return NT_STATUS_ACCESS_DENIED;
 592                         }
 593
 594                         if (output_token.length < 4) {
 595                                 return NT_STATUS_INVALID_PARAMETER;
 596                         }
 597
 598                         memcpy(maxlength_proposed, output_token.value, 4);
 599                         gss_release_buffer(&min_stat, &output_token);
 600
 601                         /* first byte is the proposed security */
 602                         security_supported = maxlength_proposed[0];
 603                         maxlength_proposed[0] = '\0';
 604
 605                         /* Rest is the proposed max wrap length */
 606                         gensec_gssapi_state->max_wrap_buf_size = MIN(RIVAL(maxlength_proposed, 0),
 607                                                                      gensec_gssapi_state->max_wrap_buf_size);
 608                         gensec_gssapi_state->sasl_protection = 0;
 609                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 610                                 if (security_supported & NEG_SEAL) {
 611                                         gensec_gssapi_state->sasl_protection |= NEG_SEAL;
 612                                 }
 613                         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 614                                 if (security_supported & NEG_SIGN) {
 615                                         gensec_gssapi_state->sasl_protection |= NEG_SIGN;
 616                                 }
 617                         } else if (security_supported & NEG_NONE) {
 618                                 gensec_gssapi_state->sasl_protection |= NEG_NONE;
 619                         } else {
 620                                 DEBUG(1, ("Remote server does not support unprotected connections"));
 621                                 return NT_STATUS_ACCESS_DENIED;
 622                         }
 623
 624                         /* Send back the negotiated max length */
 625
 626                         RSIVAL(maxlength_accepted, 0, gensec_gssapi_state->max_wrap_buf_size);
 627
 628                         maxlength_accepted[0] = gensec_gssapi_state->sasl_protection;
 629
 630                         input_token.value = maxlength_accepted;
 631                         input_token.length = sizeof(maxlength_accepted);
 632
 633                         maj_stat = gss_wrap(&min_stat,
 634                                             gensec_gssapi_state->gssapi_context,
 635                                             false,
 636                                             GSS_C_QOP_DEFAULT,
 637                                             &input_token,
 638                                             &conf_state,
 639                                             &output_token);
 640                         if (GSS_ERROR(maj_stat)) {
 641                                 DEBUG(1, ("GSS Update(SSF_NEG): GSS Wrap failed: %s\n",
 642                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 643                                 return NT_STATUS_ACCESS_DENIED;
 644                         }
 645
 646                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 647                         gss_release_buffer(&min_stat, &output_token);
 648
 649                         /* quirk:  This changes the value that gensec_have_feature returns, to be that after SASL negotiation */
 650                         gensec_gssapi_state->sasl_state = STAGE_DONE;
 651
 652                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 653                                 DEBUG(3, ("SASL/GSSAPI Connection to server will be cryptographicly sealed\n"));
 654                         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 655                                 DEBUG(3, ("SASL/GSSAPI Connection to server will be cryptographicly signed\n"));
 656                         } else {
 657                                 DEBUG(3, ("SASL/GSSAPI Connection to server will have no cryptographicly protection\n"));
 658                         }
 659
 660                         return NT_STATUS_OK;
 661                 }
 662                 case GENSEC_SERVER:
 663                 {
 664                         uint8_t maxlength_proposed[4];
 665                         uint8_t security_supported = 0x0;
 666                         int conf_state;
 667
 668                         /* As a server, we have just been sent a zero-length blob (note this, but it isn't fatal) */
 669                         if (in.length != 0) {
 670                                 DEBUG(1, ("SASL/GSSAPI: client sent non-zero length starting SASL negotiation!\n"));
 671                         }
 672
 673                         /* Give the client some idea what we will support */
 674
 675                         RSIVAL(maxlength_proposed, 0, gensec_gssapi_state->max_wrap_buf_size);
 676                         /* first byte is the proposed security */
 677                         maxlength_proposed[0] = '\0';
 678
 679                         gensec_gssapi_state->sasl_protection = 0;
 680                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 681                                 security_supported |= NEG_SEAL;
 682                         }
 683                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 684                                 security_supported |= NEG_SIGN;
 685                         }
 686                         if (security_supported == 0) {
 687                                 /* If we don't support anything, this must be 0 */
 688                                 RSIVAL(maxlength_proposed, 0, 0x0);
 689                         }
 690
 691                         /* TODO:  We may not wish to support this */
 692                         security_supported |= NEG_NONE;
 693                         maxlength_proposed[0] = security_supported;
 694
 695                         input_token.value = maxlength_proposed;
 696                         input_token.length = sizeof(maxlength_proposed);
 697
 698                         maj_stat = gss_wrap(&min_stat,
 699                                             gensec_gssapi_state->gssapi_context,
 700                                             false,
 701                                             GSS_C_QOP_DEFAULT,
 702                                             &input_token,
 703                                             &conf_state,
 704                                             &output_token);
 705                         if (GSS_ERROR(maj_stat)) {
 706                                 DEBUG(1, ("GSS Update(SSF_NEG): GSS Wrap failed: %s\n",
 707                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 708                                 return NT_STATUS_ACCESS_DENIED;
 709                         }
 710
 711                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 712                         gss_release_buffer(&min_stat, &output_token);
 713
 714                         gensec_gssapi_state->sasl_state = STAGE_SASL_SSF_ACCEPT;
 715                         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 716                 }
 717                 default:
 718                         return NT_STATUS_INVALID_PARAMETER;
 719
 720                 }
 721         }
 722         /* This is s server-only stage */
 723         case STAGE_SASL_SSF_ACCEPT:
 724         {
 725                 uint8_t maxlength_accepted[4];
 726                 uint8_t security_accepted;
 727                 int conf_state;
 728                 gss_qop_t qop_state;
 729                 input_token.length = in.length;
 730                 input_token.value = in.data;
 731
 732                 maj_stat = gss_unwrap(&min_stat,
 733                                       gensec_gssapi_state->gssapi_context,
 734                                       &input_token,
 735                                       &output_token,
 736                                       &conf_state,
 737                                       &qop_state);
 738                 if (GSS_ERROR(maj_stat)) {
 739                         DEBUG(1, ("gensec_gssapi_update: GSS UnWrap of SASL protection negotiation failed: %s\n",
 740                                   gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 741                         return NT_STATUS_ACCESS_DENIED;
 742                 }
 743
 744                 if (output_token.length < 4) {
 745                         return NT_STATUS_INVALID_PARAMETER;
 746                 }
 747
 748                 memcpy(maxlength_accepted, output_token.value, 4);
 749                 gss_release_buffer(&min_stat, &output_token);
 750
 751                 /* first byte is the proposed security */
 752                 security_accepted = maxlength_accepted[0];
 753                 maxlength_accepted[0] = '\0';
 754
 755                 /* Rest is the proposed max wrap length */
 756                 gensec_gssapi_state->max_wrap_buf_size = MIN(RIVAL(maxlength_accepted, 0),
 757                                                              gensec_gssapi_state->max_wrap_buf_size);
 758
 759                 gensec_gssapi_state->sasl_protection = 0;
 760                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 761                         if (security_accepted & NEG_SEAL) {
 762                                 gensec_gssapi_state->sasl_protection |= NEG_SEAL;
 763                         }
 764                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 765                         if (security_accepted & NEG_SIGN) {
 766                                 gensec_gssapi_state->sasl_protection |= NEG_SIGN;
 767                         }
 768                 } else if (security_accepted & NEG_NONE) {
 769                         gensec_gssapi_state->sasl_protection |= NEG_NONE;
 770                 } else {
 771                         DEBUG(1, ("Remote client does not support unprotected connections, but we failed to negotiate anything better"));
 772                         return NT_STATUS_ACCESS_DENIED;
 773                 }
 774
 775                 /* quirk:  This changes the value that gensec_have_feature returns, to be that after SASL negotiation */
 776                 gensec_gssapi_state->sasl_state = STAGE_DONE;
 777                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 778                         DEBUG(5, ("SASL/GSSAPI Connection from client will be cryptographicly sealed\n"));
 779                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 780                         DEBUG(5, ("SASL/GSSAPI Connection from client will be cryptographicly signed\n"));
 781                 } else {
 782                         DEBUG(5, ("SASL/GSSAPI Connection from client will have no cryptographic protection\n"));
 783                 }
 784
 785                 *out = data_blob(NULL, 0);
 786                 return NT_STATUS_OK;
 787         }
 788         default:
 789                 return NT_STATUS_INVALID_PARAMETER;
 790         }
 791 }
 792
 793 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 794                                    TALLOC_CTX *mem_ctx,
 795                                    const DATA_BLOB *in,
 796                                    DATA_BLOB *out)
 797 {
 798         struct gensec_gssapi_state *gensec_gssapi_state
 799                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 800         OM_uint32 maj_stat, min_stat;
 801         gss_buffer_desc input_token, output_token;
 802         int conf_state;
 803         input_token.length = in->length;
 804         input_token.value = in->data;
 805
 806         maj_stat = gss_wrap(&min_stat,
 807                             gensec_gssapi_state->gssapi_context,
 808                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 809                             GSS_C_QOP_DEFAULT,
 810                             &input_token,
 811                             &conf_state,
 812                             &output_token);
 813         if (GSS_ERROR(maj_stat)) {
 814                 DEBUG(1, ("gensec_gssapi_wrap: GSS Wrap failed: %s\n",
 815                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 816                 return NT_STATUS_ACCESS_DENIED;
 817         }
 818
 819         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 820         gss_release_buffer(&min_stat, &output_token);
 821
 822         if (gensec_gssapi_state->sasl) {
 823                 size_t max_wrapped_size = gensec_gssapi_max_wrapped_size(gensec_security);
 824                 if (max_wrapped_size < out->length) {
 825                         DEBUG(1, ("gensec_gssapi_wrap: when wrapped, INPUT data (%u) is grew to be larger than SASL negotiated maximum output size (%u > %u)\n",
 826                                   (unsigned)in->length,
 827                                   (unsigned)out->length,
 828                                   (unsigned int)max_wrapped_size));
 829                         return NT_STATUS_INVALID_PARAMETER;
 830                 }
 831         }
 832
 833         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 834             && !conf_state) {
 835                 return NT_STATUS_ACCESS_DENIED;
 836         }
 837         return NT_STATUS_OK;
 838 }
 839
 840 static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 841                                      TALLOC_CTX *mem_ctx,
 842                                      const DATA_BLOB *in,
 843                                      DATA_BLOB *out)
 844 {
 845         struct gensec_gssapi_state *gensec_gssapi_state
 846                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 847         OM_uint32 maj_stat, min_stat;
 848         gss_buffer_desc input_token, output_token;
 849         int conf_state;
 850         gss_qop_t qop_state;
 851         input_token.length = in->length;
 852         input_token.value = in->data;
 853
 854         if (gensec_gssapi_state->sasl) {
 855                 size_t max_wrapped_size = gensec_gssapi_max_wrapped_size(gensec_security);
 856                 if (max_wrapped_size < in->length) {
 857                         DEBUG(1, ("gensec_gssapi_unwrap: WRAPPED data is larger than SASL negotiated maximum size\n"));
 858                         return NT_STATUS_INVALID_PARAMETER;
 859                 }
 860         }
 861
 862         maj_stat = gss_unwrap(&min_stat,
 863                               gensec_gssapi_state->gssapi_context,
 864                               &input_token,
 865                               &output_token,
 866                               &conf_state,
 867                               &qop_state);
 868         if (GSS_ERROR(maj_stat)) {
 869                 DEBUG(1, ("gensec_gssapi_unwrap: GSS UnWrap failed: %s\n",
 870                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 871                 return NT_STATUS_ACCESS_DENIED;
 872         }
 873
 874         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 875         gss_release_buffer(&min_stat, &output_token);
 876
 877         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 878             && !conf_state) {
 879                 return NT_STATUS_ACCESS_DENIED;
 880         }
 881         return NT_STATUS_OK;
 882 }
 883
 884 /* Find out the maximum input size negotiated on this connection */
 885
 886 static size_t gensec_gssapi_max_input_size(struct gensec_security *gensec_security)
 887 {
 888         struct gensec_gssapi_state *gensec_gssapi_state
 889                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 890         OM_uint32 maj_stat, min_stat;
 891         OM_uint32 max_input_size;
 892
 893         maj_stat = gss_wrap_size_limit(&min_stat,
 894                                        gensec_gssapi_state->gssapi_context,
 895                                        gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 896                                        GSS_C_QOP_DEFAULT,
 897                                        gensec_gssapi_state->max_wrap_buf_size,
 898                                        &max_input_size);
 899         if (GSS_ERROR(maj_stat)) {
 900                 TALLOC_CTX *mem_ctx = talloc_new(NULL);
 901                 DEBUG(1, ("gensec_gssapi_max_input_size: determinaing signature size with gss_wrap_size_limit failed: %s\n",
 902                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 903                 talloc_free(mem_ctx);
 904                 return 0;
 905         }
 906
 907         return max_input_size;
 908 }
 909
 910 /* Find out the maximum output size negotiated on this connection */
 911 static size_t gensec_gssapi_max_wrapped_size(struct gensec_security *gensec_security)
 912 {
 913         struct gensec_gssapi_state *gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);;
 914         return gensec_gssapi_state->max_wrap_buf_size;
 915 }
 916
 917 static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_security,
 918                                           TALLOC_CTX *mem_ctx,
 919                                           uint8_t *data, size_t length,
 920                                           const uint8_t *whole_pdu, size_t pdu_length,
 921                                           DATA_BLOB *sig)
 922 {
 923         struct gensec_gssapi_state *gensec_gssapi_state
 924                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 925         OM_uint32 maj_stat, min_stat;
 926         gss_buffer_desc input_token, output_token;
 927         int conf_state;
 928         ssize_t sig_length;
 929
 930         input_token.length = length;
 931         input_token.value = data;
 932
 933         maj_stat = gss_wrap(&min_stat,
 934                             gensec_gssapi_state->gssapi_context,
 935                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 936                             GSS_C_QOP_DEFAULT,
 937                             &input_token,
 938                             &conf_state,
 939                             &output_token);
 940         if (GSS_ERROR(maj_stat)) {
 941                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap failed: %s\n",
 942                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 943                 return NT_STATUS_ACCESS_DENIED;
 944         }
 945
 946         if (output_token.length < input_token.length) {
 947                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap length [%ld] *less* than caller length [%ld]\n",
 948                           (long)output_token.length, (long)length));
 949                 return NT_STATUS_INTERNAL_ERROR;
 950         }
 951         sig_length = output_token.length - input_token.length;
 952
 953         memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);
 954         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 955
 956         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 957         dump_data_pw("gensec_gssapi_seal_packet: clear\n", data, length);
 958         dump_data_pw("gensec_gssapi_seal_packet: sealed\n", ((uint8_t *)output_token.value) + sig_length, output_token.length - sig_length);
 959
 960         gss_release_buffer(&min_stat, &output_token);
 961
 962         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 963             && !conf_state) {
 964                 return NT_STATUS_ACCESS_DENIED;
 965         }
 966         return NT_STATUS_OK;
 967 }
 968
 969 static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_security,
 970                                             TALLOC_CTX *mem_ctx,
 971                                             uint8_t *data, size_t length,
 972                                             const uint8_t *whole_pdu, size_t pdu_length,
 973                                             const DATA_BLOB *sig)
 974 {
 975         struct gensec_gssapi_state *gensec_gssapi_state
 976                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 977         OM_uint32 maj_stat, min_stat;
 978         gss_buffer_desc input_token, output_token;
 979         int conf_state;
 980         gss_qop_t qop_state;
 981         DATA_BLOB in;
 982
 983         dump_data_pw("gensec_gssapi_unseal_packet: sig\n", sig->data, sig->length);
 984
 985         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 986
 987         memcpy(in.data, sig->data, sig->length);
 988         memcpy(in.data + sig->length, data, length);
 989
 990         input_token.length = in.length;
 991         input_token.value = in.data;
 992
 993         maj_stat = gss_unwrap(&min_stat,
 994                               gensec_gssapi_state->gssapi_context,
 995                               &input_token,
 996                               &output_token,
 997                               &conf_state,
 998                               &qop_state);
 999         if (GSS_ERROR(maj_stat)) {
1000                 DEBUG(1, ("gensec_gssapi_unseal_packet: GSS UnWrap failed: %s\n",
1001                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1002                 return NT_STATUS_ACCESS_DENIED;
1003         }
1004
1005         if (output_token.length != length) {
1006                 return NT_STATUS_INTERNAL_ERROR;
1007         }
1008
1009         memcpy(data, output_token.value, length);
1010
1011         gss_release_buffer(&min_stat, &output_token);
1012
1013         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
1014             && !conf_state) {
1015                 return NT_STATUS_ACCESS_DENIED;
1016         }
1017         return NT_STATUS_OK;
1018 }
1019
1020 static NTSTATUS gensec_gssapi_sign_packet(struct gensec_security *gensec_security,
1021                                           TALLOC_CTX *mem_ctx,
1022                                           const uint8_t *data, size_t length,
1023                                           const uint8_t *whole_pdu, size_t pdu_length,
1024                                           DATA_BLOB *sig)
1025 {
1026         struct gensec_gssapi_state *gensec_gssapi_state
1027                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1028         OM_uint32 maj_stat, min_stat;
1029         gss_buffer_desc input_token, output_token;
1030         int conf_state;
1031         ssize_t sig_length = 0;
1032
1033         input_token.length = length;
1034         input_token.value = discard_const_p(uint8_t *, data);
1035
1036         maj_stat = gss_wrap(&min_stat,
1037                             gensec_gssapi_state->gssapi_context,
1038                             0,
1039                             GSS_C_QOP_DEFAULT,
1040                             &input_token,
1041                             &conf_state,
1042                             &output_token);
1043         if (GSS_ERROR(maj_stat)) {
1044                 DEBUG(1, ("GSS Wrap failed: %s\n",
1045                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1046                 return NT_STATUS_ACCESS_DENIED;
1047         }
1048
1049         if (output_token.length < input_token.length) {
1050                 DEBUG(1, ("gensec_gssapi_sign_packet: GSS Wrap length [%ld] *less* than caller length [%ld]\n",
1051                           (long)output_token.length, (long)length));
1052                 return NT_STATUS_INTERNAL_ERROR;
1053         }
1054
1055         /* Caller must pad to right boundary */
1056         sig_length = output_token.length - input_token.length;
1057
1058         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
1059
1060         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
1061
1062         gss_release_buffer(&min_stat, &output_token);
1063
1064         return NT_STATUS_OK;
1065 }
1066
1067 static NTSTATUS gensec_gssapi_check_packet(struct gensec_security *gensec_security,
1068                                            TALLOC_CTX *mem_ctx,
1069                                            const uint8_t *data, size_t length,
1070                                            const uint8_t *whole_pdu, size_t pdu_length,
1071                                            const DATA_BLOB *sig)
1072 {
1073         struct gensec_gssapi_state *gensec_gssapi_state
1074                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1075         OM_uint32 maj_stat, min_stat;
1076         gss_buffer_desc input_token, output_token;
1077         int conf_state;
1078         gss_qop_t qop_state;
1079         DATA_BLOB in;
1080
1081         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
1082
1083         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
1084
1085         memcpy(in.data, sig->data, sig->length);
1086         memcpy(in.data + sig->length, data, length);
1087
1088         input_token.length = in.length;
1089         input_token.value = in.data;
1090
1091         maj_stat = gss_unwrap(&min_stat,
1092                               gensec_gssapi_state->gssapi_context,
1093                               &input_token,
1094                               &output_token,
1095                               &conf_state,
1096                               &qop_state);
1097         if (GSS_ERROR(maj_stat)) {
1098                 DEBUG(1, ("GSS UnWrap failed: %s\n",
1099                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1100                 return NT_STATUS_ACCESS_DENIED;
1101         }
1102
1103         if (output_token.length != length) {
1104                 return NT_STATUS_INTERNAL_ERROR;
1105         }
1106
1107         gss_release_buffer(&min_stat, &output_token);
1108
1109         return NT_STATUS_OK;
1110 }
1111
1112 /* Try to figure out what features we actually got on the connection */
1113 static bool gensec_gssapi_have_feature(struct gensec_security *gensec_security,
1114                                        uint32_t feature)
1115 {
1116         struct gensec_gssapi_state *gensec_gssapi_state
1117                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1118         if (feature & GENSEC_FEATURE_SIGN) {
1119                 /* If we are going GSSAPI SASL, then we honour the second negotiation */
1120                 if (gensec_gssapi_state->sasl
1121                     && gensec_gssapi_state->sasl_state == STAGE_DONE) {
1122                         return ((gensec_gssapi_state->sasl_protection & NEG_SIGN)
1123                                 && (gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG));
1124                 }
1125                 return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
1126         }
1127         if (feature & GENSEC_FEATURE_SEAL) {
1128                 /* If we are going GSSAPI SASL, then we honour the second negotiation */
1129                 if (gensec_gssapi_state->sasl
1130                     && gensec_gssapi_state->sasl_state == STAGE_DONE) {
1131                         return ((gensec_gssapi_state->sasl_protection & NEG_SEAL)
1132                                  && (gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG));
1133                 }
1134                 return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
1135         }
1136         if (feature & GENSEC_FEATURE_SESSION_KEY) {
1137                 /* Only for GSSAPI/Krb5 */
1138                 if (gss_oid_equal(gensec_gssapi_state->gss_oid, gss_mech_krb5)) {
1139                         return true;
1140                 }
1141         }
1142         if (feature & GENSEC_FEATURE_DCE_STYLE) {
1143                 return gensec_gssapi_state->got_flags & GSS_C_DCE_STYLE;
1144         }
1145         /* We can always do async (rather than strict request/reply) packets.  */
1146         if (feature & GENSEC_FEATURE_ASYNC_REPLIES) {
1147                 return true;
1148         }
1149         return false;
1150 }
1151
1152 /*
1153  * Extract the 'sesssion key' needed by SMB signing and ncacn_np
1154  * (for encrypting some passwords).
1155  *
1156  * This breaks all the abstractions, but what do you expect...
1157  */
1158 static NTSTATUS gensec_gssapi_session_key(struct gensec_security *gensec_security,
1159                                           DATA_BLOB *session_key)
1160 {
1161         struct gensec_gssapi_state *gensec_gssapi_state
1162                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1163         OM_uint32 maj_stat, min_stat;
1164         krb5_keyblock *subkey;
1165
1166         if (gensec_gssapi_state->session_key.data) {
1167                 *session_key = gensec_gssapi_state->session_key;
1168                 return NT_STATUS_OK;
1169         }
1170
1171         maj_stat = gsskrb5_get_initiator_subkey(&min_stat,
1172                                                 gensec_gssapi_state->gssapi_context,
1173                                                 &subkey);
1174         if (maj_stat != 0) {
1175                 DEBUG(1, ("NO session key for this mech\n"));
1176                 return NT_STATUS_NO_USER_SESSION_KEY;
1177         }
1178
1179         DEBUG(10, ("Got KRB5 session key of length %d\n",
1180                    (int)KRB5_KEY_LENGTH(subkey)));
1181         gensec_gssapi_state->session_key = data_blob_talloc(gensec_gssapi_state,
1182                                                             KRB5_KEY_DATA(subkey), KRB5_KEY_LENGTH(subkey));
1183         krb5_free_keyblock(gensec_gssapi_state->smb_krb5_context->krb5_context, subkey);
1184         *session_key = gensec_gssapi_state->session_key;
1185         dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
1186
1187         return NT_STATUS_OK;
1188 }
1189
1190 /* Get some basic (and authorization) information about the user on
1191  * this session.  This uses either the PAC (if present) or a local
1192  * database lookup */
1193 static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_security,
1194                                            struct auth_session_info **_session_info)
1195 {
1196         NTSTATUS nt_status;
1197         TALLOC_CTX *mem_ctx;
1198         struct gensec_gssapi_state *gensec_gssapi_state
1199                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1200         struct auth_serversupplied_info *server_info = NULL;
1201         struct auth_session_info *session_info = NULL;
1202         struct PAC_LOGON_INFO *logon_info;
1203         OM_uint32 maj_stat, min_stat;
1204         gss_buffer_desc name_token;
1205         gss_buffer_desc pac;
1206         krb5_keyblock *keyblock;
1207         time_t authtime;
1208         krb5_principal principal;
1209         char *principal_string;
1210         DATA_BLOB pac_blob;
1211
1212         if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
1213             || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
1214                        gensec_gssapi_state->gss_oid->length) != 0)) {
1215                 DEBUG(1, ("NO session info available for this mech\n"));
1216                 return NT_STATUS_INVALID_PARAMETER;
1217         }
1218
1219         mem_ctx = talloc_named(gensec_gssapi_state, 0, "gensec_gssapi_session_info context");
1220         NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
1221
1222         maj_stat = gss_display_name (&min_stat,
1223                                      gensec_gssapi_state->client_name,
1224                                      &name_token,
1225                                      NULL);
1226         if (GSS_ERROR(maj_stat)) {
1227                 DEBUG(1, ("GSS display_name failed: %s\n",
1228                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1229                 talloc_free(mem_ctx);
1230                 return NT_STATUS_FOOBAR;
1231         }
1232
1233         principal_string = talloc_strndup(mem_ctx,
1234                                           (const char *)name_token.value,
1235                                           name_token.length);
1236
1237         gss_release_buffer(&min_stat, &name_token);
1238
1239         if (!principal_string) {
1240                 talloc_free(mem_ctx);
1241                 return NT_STATUS_NO_MEMORY;
1242         }
1243
1244         maj_stat = gsskrb5_extract_authz_data_from_sec_context(&min_stat,
1245                                                                gensec_gssapi_state->gssapi_context,
1246                                                                KRB5_AUTHDATA_WIN2K_PAC,
1247                                                                &pac);
1248
1249
1250         if (maj_stat == 0) {
1251                 pac_blob = data_blob_talloc(mem_ctx, pac.value, pac.length);
1252                 gss_release_buffer(&min_stat, &pac);
1253
1254         } else {
1255                 pac_blob = data_blob(NULL, 0);
1256         }
1257
1258         /* IF we have the PAC - otherwise we need to get this
1259          * data from elsewere - local ldb, or (TODO) lookup of some
1260          * kind...
1261          */
1262         if (pac_blob.length) {
1263                 krb5_error_code ret;
1264                 union netr_Validation validation;
1265
1266                 maj_stat = gsskrb5_extract_authtime_from_sec_context(&min_stat,
1267                                                                      gensec_gssapi_state->gssapi_context,
1268                                                                      &authtime);
1269
1270                 if (GSS_ERROR(maj_stat)) {
1271                         DEBUG(1, ("gsskrb5_extract_authtime_from_sec_context: %s\n",
1272                                   gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1273                         talloc_free(mem_ctx);
1274                         return NT_STATUS_FOOBAR;
1275                 }
1276
1277                 maj_stat = gsskrb5_extract_service_keyblock(&min_stat,
1278                                                             gensec_gssapi_state->gssapi_context,
1279                                                             &keyblock);
1280
1281                 if (GSS_ERROR(maj_stat)) {
1282                         DEBUG(1, ("gsskrb5_copy_service_keyblock failed: %s\n",
1283                                   gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1284                         talloc_free(mem_ctx);
1285                         return NT_STATUS_FOOBAR;
1286                 }
1287
1288                 ret = krb5_parse_name_flags(gensec_gssapi_state->smb_krb5_context->krb5_context,
1289                                             principal_string,
1290                                             KRB5_PRINCIPAL_PARSE_MUST_REALM,
1291                                             &principal);
1292                 if (ret) {
1293                         krb5_free_keyblock(gensec_gssapi_state->smb_krb5_context->krb5_context,
1294                                            keyblock);
1295                         talloc_free(mem_ctx);
1296                         return NT_STATUS_INVALID_PARAMETER;
1297                 }
1298
1299                 /* decode and verify the pac */
1300                 nt_status = kerberos_pac_logon_info(mem_ctx, &logon_info, pac_blob,
1301                                                     gensec_gssapi_state->smb_krb5_context->krb5_context,
1302                                                     NULL, keyblock, principal, authtime, NULL);
1303                 krb5_free_principal(gensec_gssapi_state->smb_krb5_context->krb5_context, principal);
1304                 krb5_free_keyblock(gensec_gssapi_state->smb_krb5_context->krb5_context,
1305                                    keyblock);
1306
1307                 if (!NT_STATUS_IS_OK(nt_status)) {
1308                         talloc_free(mem_ctx);
1309                         return nt_status;
1310                 }
1311                 validation.sam3 = &logon_info->info3;
1312                 nt_status = make_server_info_netlogon_validation(gensec_gssapi_state,
1313                                                                  NULL,
1314                                                                  3, &validation,
1315                                                                  &server_info);
1316                 if (!NT_STATUS_IS_OK(nt_status)) {
1317                         talloc_free(mem_ctx);
1318                         return nt_status;
1319                 }
1320         } else if (!lp_parm_bool(global_loadparm, NULL, "gensec", "require_pac", false)) {
1321                 DEBUG(1, ("Unable to find PAC, resorting to local user lookup: %s\n",
1322                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1323                 nt_status = sam_get_server_info_principal(mem_ctx, principal_string,
1324                                                           &server_info);
1325
1326                 if (!NT_STATUS_IS_OK(nt_status)) {
1327                         talloc_free(mem_ctx);
1328                         return nt_status;
1329                 }
1330         } else {
1331                 DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access: %s\n",
1332                           principal_string,
1333                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1334                 return NT_STATUS_ACCESS_DENIED;
1335         }
1336
1337         /* references the server_info into the session_info */
1338         nt_status = auth_generate_session_info(mem_ctx, server_info, &session_info);
1339         if (!NT_STATUS_IS_OK(nt_status)) {
1340                 talloc_free(mem_ctx);
1341                 return nt_status;
1342         }
1343
1344         nt_status = gensec_gssapi_session_key(gensec_security, &session_info->session_key);
1345         if (!NT_STATUS_IS_OK(nt_status)) {
1346                 talloc_free(mem_ctx);
1347                 return nt_status;
1348         }
1349
1350         if (!(gensec_gssapi_state->got_flags & GSS_C_DELEG_FLAG)) {
1351                 DEBUG(10, ("gensec_gssapi: NO delegated credentials supplied by client\n"));
1352         } else {
1353                 krb5_error_code ret;
1354                 DEBUG(10, ("gensec_gssapi: delegated credentials supplied by client\n"));
1355                 session_info->credentials = cli_credentials_init(session_info);
1356                 if (!session_info->credentials) {
1357                         talloc_free(mem_ctx);
1358                         return NT_STATUS_NO_MEMORY;
1359                 }
1360
1361                 cli_credentials_set_event_context(session_info->credentials, gensec_security->event_ctx);
1362                 cli_credentials_set_conf(session_info->credentials, global_loadparm);
1363                 /* Just so we don't segfault trying to get at a username */
1364                 cli_credentials_set_anonymous(session_info->credentials);
1365
1366                 ret = cli_credentials_set_client_gss_creds(session_info->credentials,
1367                                                            gensec_gssapi_state->delegated_cred_handle,
1368                                                            CRED_SPECIFIED);
1369                 if (ret) {
1370                         talloc_free(mem_ctx);
1371                         return NT_STATUS_NO_MEMORY;
1372                 }
1373
1374                 /* This credential handle isn't useful for password authentication, so ensure nobody tries to do that */
1375                 cli_credentials_set_kerberos_state(session_info->credentials, CRED_MUST_USE_KERBEROS);
1376
1377                 /* It has been taken from this place... */
1378                 gensec_gssapi_state->delegated_cred_handle = GSS_C_NO_CREDENTIAL;
1379         }
1380         talloc_steal(gensec_gssapi_state, session_info);
1381         talloc_free(mem_ctx);
1382         *_session_info = session_info;
1383
1384         return NT_STATUS_OK;
1385 }
1386
1387 static const char *gensec_gssapi_krb5_oids[] = {
1388         GENSEC_OID_KERBEROS5_OLD,
1389         GENSEC_OID_KERBEROS5,
1390         NULL
1391 };
1392
1393 static const char *gensec_gssapi_spnego_oids[] = {
1394         GENSEC_OID_SPNEGO,
1395         NULL
1396 };
1397
1398 /* As a server, this could in theory accept any GSSAPI mech */
1399 static const struct gensec_security_ops gensec_gssapi_spnego_security_ops = {
1400         .name           = "gssapi_spnego",
1401         .sasl_name      = "GSS-SPNEGO",
1402         .auth_type      = DCERPC_AUTH_TYPE_SPNEGO,
1403         .oid            = gensec_gssapi_spnego_oids,
1404         .client_start   = gensec_gssapi_client_start,
1405         .server_start   = gensec_gssapi_server_start,
1406         .magic          = gensec_gssapi_magic,
1407         .update         = gensec_gssapi_update,
1408         .session_key    = gensec_gssapi_session_key,
1409         .session_info   = gensec_gssapi_session_info,
1410         .sign_packet    = gensec_gssapi_sign_packet,
1411         .check_packet   = gensec_gssapi_check_packet,
1412         .seal_packet    = gensec_gssapi_seal_packet,
1413         .unseal_packet  = gensec_gssapi_unseal_packet,
1414         .wrap           = gensec_gssapi_wrap,
1415         .unwrap         = gensec_gssapi_unwrap,
1416         .have_feature   = gensec_gssapi_have_feature,
1417         .enabled        = false,
1418         .kerberos       = true,
1419         .priority       = GENSEC_GSSAPI
1420 };
1421
1422 /* As a server, this could in theory accept any GSSAPI mech */
1423 static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
1424         .name           = "gssapi_krb5",
1425         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
1426         .oid            = gensec_gssapi_krb5_oids,
1427         .client_start   = gensec_gssapi_client_start,
1428         .server_start   = gensec_gssapi_server_start,
1429         .magic          = gensec_gssapi_magic,
1430         .update         = gensec_gssapi_update,
1431         .session_key    = gensec_gssapi_session_key,
1432         .session_info   = gensec_gssapi_session_info,
1433         .sign_packet    = gensec_gssapi_sign_packet,
1434         .check_packet   = gensec_gssapi_check_packet,
1435         .seal_packet    = gensec_gssapi_seal_packet,
1436         .unseal_packet  = gensec_gssapi_unseal_packet,
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 /* As a server, this could in theory accept any GSSAPI mech */
1446 static const struct gensec_security_ops gensec_gssapi_sasl_krb5_security_ops = {
1447         .name             = "gssapi_krb5_sasl",
1448         .sasl_name        = "GSSAPI",
1449         .client_start     = gensec_gssapi_sasl_client_start,
1450         .server_start     = gensec_gssapi_sasl_server_start,
1451         .update           = gensec_gssapi_update,
1452         .session_key      = gensec_gssapi_session_key,
1453         .session_info     = gensec_gssapi_session_info,
1454         .max_input_size   = gensec_gssapi_max_input_size,
1455         .max_wrapped_size = gensec_gssapi_max_wrapped_size,
1456         .wrap             = gensec_gssapi_wrap,
1457         .unwrap           = gensec_gssapi_unwrap,
1458         .have_feature     = gensec_gssapi_have_feature,
1459         .enabled          = true,
1460         .kerberos         = true,
1461         .priority         = GENSEC_GSSAPI
1462 };
1463
1464 NTSTATUS gensec_gssapi_init(void)
1465 {
1466         NTSTATUS ret;
1467
1468         ret = gensec_register(&gensec_gssapi_spnego_security_ops);
1469         if (!NT_STATUS_IS_OK(ret)) {
1470                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1471                         gensec_gssapi_spnego_security_ops.name));
1472                 return ret;
1473         }
1474
1475         ret = gensec_register(&gensec_gssapi_krb5_security_ops);
1476         if (!NT_STATUS_IS_OK(ret)) {
1477                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1478                         gensec_gssapi_krb5_security_ops.name));
1479                 return ret;
1480         }
1481
1482         ret = gensec_register(&gensec_gssapi_sasl_krb5_security_ops);
1483         if (!NT_STATUS_IS_OK(ret)) {
1484                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1485                         gensec_gssapi_sasl_krb5_security_ops.name));
1486                 return ret;
1487         }
1488
1489         return ret;
1490 }