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 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 "auth/kerberos/kerberos.h"
  28 #include "librpc/gen_ndr/krb5pac.h"
  29 #include "auth/auth.h"
  30 #include "lib/ldb/include/ldb.h"
  31 #include "auth/auth_sam.h"
  32 #include "librpc/rpc/dcerpc.h"
  33 #include "auth/credentials/credentials.h"
  34 #include "auth/credentials/credentials_krb5.h"
  35 #include "auth/gensec/gensec.h"
  36 #include "auth/gensec/gensec_proto.h"
  37 #include "param/param.h"
  38 #include "auth/session_proto.h"
  39 #include <gssapi/gssapi.h>
  40 #include <gssapi/gssapi_krb5.h>
  41 #include <gssapi/gssapi_spnego.h>
  42 #include "auth/gensec/gensec_gssapi.h"
  43 #include "lib/util/util_net.h"
  44
  45 static size_t gensec_gssapi_max_input_size(struct gensec_security *gensec_security);
  46 static size_t gensec_gssapi_max_wrapped_size(struct gensec_security *gensec_security);
  47
  48 static char *gssapi_error_string(TALLOC_CTX *mem_ctx,
  49                                  OM_uint32 maj_stat, OM_uint32 min_stat,
  50                                  const gss_OID mech)
  51 {
  52         OM_uint32 disp_min_stat, disp_maj_stat;
  53         gss_buffer_desc maj_error_message;
  54         gss_buffer_desc min_error_message;
  55         char *maj_error_string, *min_error_string;
  56         OM_uint32 msg_ctx = 0;
  57
  58         char *ret;
  59
  60         maj_error_message.value = NULL;
  61         min_error_message.value = NULL;
  62         maj_error_message.length = 0;
  63         min_error_message.length = 0;
  64
  65         disp_maj_stat = gss_display_status(&disp_min_stat, maj_stat, GSS_C_GSS_CODE,
  66                            mech, &msg_ctx, &maj_error_message);
  67         disp_maj_stat = gss_display_status(&disp_min_stat, min_stat, GSS_C_MECH_CODE,
  68                            mech, &msg_ctx, &min_error_message);
  69
  70         maj_error_string = talloc_strndup(mem_ctx, (char *)maj_error_message.value, maj_error_message.length);
  71
  72         min_error_string = talloc_strndup(mem_ctx, (char *)min_error_message.value, min_error_message.length);
  73
  74         ret = talloc_asprintf(mem_ctx, "%s: %s", maj_error_string, min_error_string);
  75
  76         talloc_free(maj_error_string);
  77         talloc_free(min_error_string);
  78
  79         gss_release_buffer(&disp_min_stat, &maj_error_message);
  80         gss_release_buffer(&disp_min_stat, &min_error_message);
  81
  82         return ret;
  83 }
  84
  85
  86 static int gensec_gssapi_destructor(struct gensec_gssapi_state *gensec_gssapi_state)
  87 {
  88         OM_uint32 maj_stat, min_stat;
  89
  90         if (gensec_gssapi_state->delegated_cred_handle != GSS_C_NO_CREDENTIAL) {
  91                 maj_stat = gss_release_cred(&min_stat,
  92                                             &gensec_gssapi_state->delegated_cred_handle);
  93         }
  94
  95         if (gensec_gssapi_state->gssapi_context != GSS_C_NO_CONTEXT) {
  96                 maj_stat = gss_delete_sec_context (&min_stat,
  97                                                    &gensec_gssapi_state->gssapi_context,
  98                                                    GSS_C_NO_BUFFER);
  99         }
 100
 101         if (gensec_gssapi_state->server_name != GSS_C_NO_NAME) {
 102                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->server_name);
 103         }
 104         if (gensec_gssapi_state->client_name != GSS_C_NO_NAME) {
 105                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->client_name);
 106         }
 107
 108         if (gensec_gssapi_state->lucid) {
 109                 gss_krb5_free_lucid_sec_context(&min_stat, gensec_gssapi_state->lucid);
 110         }
 111
 112         return 0;
 113 }
 114
 115 static NTSTATUS gensec_gssapi_init_lucid(struct gensec_gssapi_state *gensec_gssapi_state)
 116 {
 117         OM_uint32 maj_stat, min_stat;
 118
 119         if (gensec_gssapi_state->lucid) {
 120                 return NT_STATUS_OK;
 121         }
 122
 123         maj_stat = gss_krb5_export_lucid_sec_context(&min_stat,
 124                                                      &gensec_gssapi_state->gssapi_context,
 125                                                      1,
 126                                                      (void **)&gensec_gssapi_state->lucid);
 127         if (maj_stat != GSS_S_COMPLETE) {
 128                 DEBUG(0,("gensec_gssapi_init_lucid: %s\n",
 129                         gssapi_error_string(gensec_gssapi_state,
 130                                             maj_stat, min_stat,
 131                                             gensec_gssapi_state->gss_oid)));
 132                 return NT_STATUS_INTERNAL_ERROR;
 133         }
 134
 135         if (gensec_gssapi_state->lucid->version != 1) {
 136                 DEBUG(0,("gensec_gssapi_init_lucid: lucid version[%d] != 1\n",
 137                         gensec_gssapi_state->lucid->version));
 138                 gss_krb5_free_lucid_sec_context(&min_stat, gensec_gssapi_state->lucid);
 139                 gensec_gssapi_state->lucid = NULL;
 140                 return NT_STATUS_INTERNAL_ERROR;
 141         }
 142
 143         return NT_STATUS_OK;
 144 }
 145
 146 static NTSTATUS gensec_gssapi_start(struct gensec_security *gensec_security)
 147 {
 148         struct gensec_gssapi_state *gensec_gssapi_state;
 149         krb5_error_code ret;
 150         struct gsskrb5_send_to_kdc send_to_kdc;
 151         const char *realm;
 152
 153         gensec_gssapi_state = talloc(gensec_security, struct gensec_gssapi_state);
 154         if (!gensec_gssapi_state) {
 155                 return NT_STATUS_NO_MEMORY;
 156         }
 157
 158         gensec_gssapi_state->gss_exchange_count = 0;
 159         gensec_gssapi_state->max_wrap_buf_size
 160                 = gensec_setting_int(gensec_security->settings, "gensec_gssapi", "max wrap buf size", 65536);
 161
 162         gensec_gssapi_state->sasl = false;
 163         gensec_gssapi_state->sasl_state = STAGE_GSS_NEG;
 164
 165         gensec_security->private_data = gensec_gssapi_state;
 166
 167         gensec_gssapi_state->gssapi_context = GSS_C_NO_CONTEXT;
 168         gensec_gssapi_state->server_name = GSS_C_NO_NAME;
 169         gensec_gssapi_state->client_name = GSS_C_NO_NAME;
 170         gensec_gssapi_state->lucid = NULL;
 171
 172         /* TODO: Fill in channel bindings */
 173         gensec_gssapi_state->input_chan_bindings = GSS_C_NO_CHANNEL_BINDINGS;
 174
 175         gensec_gssapi_state->want_flags = 0;
 176         if (gensec_setting_bool(gensec_security->settings, "gensec_gssapi", "delegation_by_kdc_policy", true)) {
 177                 gensec_gssapi_state->want_flags |= GSS_C_DELEG_POLICY_FLAG;
 178         }
 179         if (gensec_setting_bool(gensec_security->settings, "gensec_gssapi", "mutual", true)) {
 180                 gensec_gssapi_state->want_flags |= GSS_C_MUTUAL_FLAG;
 181         }
 182         if (gensec_setting_bool(gensec_security->settings, "gensec_gssapi", "delegation", true)) {
 183                 gensec_gssapi_state->want_flags |= GSS_C_DELEG_FLAG;
 184         }
 185         if (gensec_setting_bool(gensec_security->settings, "gensec_gssapi", "replay", true)) {
 186                 gensec_gssapi_state->want_flags |= GSS_C_REPLAY_FLAG;
 187         }
 188         if (gensec_setting_bool(gensec_security->settings, "gensec_gssapi", "sequence", true)) {
 189                 gensec_gssapi_state->want_flags |= GSS_C_SEQUENCE_FLAG;
 190         }
 191
 192         gensec_gssapi_state->got_flags = 0;
 193
 194         gensec_gssapi_state->session_key = data_blob(NULL, 0);
 195         gensec_gssapi_state->pac = data_blob(NULL, 0);
 196
 197         gensec_gssapi_state->delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 198         gensec_gssapi_state->sig_size = 0;
 199
 200         talloc_set_destructor(gensec_gssapi_state, gensec_gssapi_destructor);
 201
 202         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 203                 gensec_gssapi_state->want_flags |= GSS_C_INTEG_FLAG;
 204         }
 205         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 206                 gensec_gssapi_state->want_flags |= GSS_C_CONF_FLAG;
 207         }
 208         if (gensec_security->want_features & GENSEC_FEATURE_DCE_STYLE) {
 209                 gensec_gssapi_state->want_flags |= GSS_C_DCE_STYLE;
 210         }
 211
 212         switch (gensec_security->ops->auth_type) {
 213         case DCERPC_AUTH_TYPE_SPNEGO:
 214                 gensec_gssapi_state->gss_oid = gss_mech_spnego;
 215                 break;
 216         case DCERPC_AUTH_TYPE_KRB5:
 217         default:
 218                 gensec_gssapi_state->gss_oid = gss_mech_krb5;
 219                 break;
 220         }
 221
 222         send_to_kdc.func = smb_krb5_send_and_recv_func;
 223         send_to_kdc.ptr = gensec_security->event_ctx;
 224
 225         ret = gsskrb5_set_send_to_kdc(&send_to_kdc);
 226         if (ret) {
 227                 DEBUG(1,("gensec_krb5_start: gsskrb5_set_send_to_kdc failed\n"));
 228                 talloc_free(gensec_gssapi_state);
 229                 return NT_STATUS_INTERNAL_ERROR;
 230         }
 231
 232         realm = lp_realm(gensec_security->settings->lp_ctx);
 233         if (realm != NULL) {
 234                 ret = gsskrb5_set_default_realm(realm);
 235                 if (ret) {
 236                         DEBUG(1,("gensec_krb5_start: gsskrb5_set_default_realm failed\n"));
 237                         talloc_free(gensec_gssapi_state);
 238                         return NT_STATUS_INTERNAL_ERROR;
 239                 }
 240         }
 241
 242         /* don't do DNS lookups of any kind, it might/will fail for a netbios name */
 243         ret = gsskrb5_set_dns_canonicalize(gensec_setting_bool(gensec_security->settings, "krb5", "set_dns_canonicalize", false));
 244         if (ret) {
 245                 DEBUG(1,("gensec_krb5_start: gsskrb5_set_dns_canonicalize failed\n"));
 246                 talloc_free(gensec_gssapi_state);
 247                 return NT_STATUS_INTERNAL_ERROR;
 248         }
 249
 250         ret = smb_krb5_init_context(gensec_gssapi_state,
 251                                     gensec_security->event_ctx,
 252                                     gensec_security->settings->lp_ctx,
 253                                     &gensec_gssapi_state->smb_krb5_context);
 254         if (ret) {
 255                 DEBUG(1,("gensec_krb5_start: krb5_init_context failed (%s)\n",
 256                          error_message(ret)));
 257                 talloc_free(gensec_gssapi_state);
 258                 return NT_STATUS_INTERNAL_ERROR;
 259         }
 260         return NT_STATUS_OK;
 261 }
 262
 263 static NTSTATUS gensec_gssapi_server_start(struct gensec_security *gensec_security)
 264 {
 265         NTSTATUS nt_status;
 266         int ret;
 267         struct gensec_gssapi_state *gensec_gssapi_state;
 268         struct cli_credentials *machine_account;
 269         struct gssapi_creds_container *gcc;
 270
 271         nt_status = gensec_gssapi_start(gensec_security);
 272         if (!NT_STATUS_IS_OK(nt_status)) {
 273                 return nt_status;
 274         }
 275
 276         gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 277
 278         machine_account = gensec_get_credentials(gensec_security);
 279
 280         if (!machine_account) {
 281                 DEBUG(3, ("No machine account credentials specified\n"));
 282                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 283         } else {
 284                 ret = cli_credentials_get_server_gss_creds(machine_account,
 285                                                            gensec_security->event_ctx,
 286                                                            gensec_security->settings->lp_ctx, &gcc);
 287                 if (ret) {
 288                         DEBUG(1, ("Aquiring acceptor credentials failed: %s\n",
 289                                   error_message(ret)));
 290                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 291                 }
 292         }
 293
 294         gensec_gssapi_state->server_cred = gcc;
 295         return NT_STATUS_OK;
 296
 297 }
 298
 299 static NTSTATUS gensec_gssapi_sasl_server_start(struct gensec_security *gensec_security)
 300 {
 301         NTSTATUS nt_status;
 302         struct gensec_gssapi_state *gensec_gssapi_state;
 303         nt_status = gensec_gssapi_server_start(gensec_security);
 304
 305         if (NT_STATUS_IS_OK(nt_status)) {
 306                 gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 307                 gensec_gssapi_state->sasl = true;
 308         }
 309         return nt_status;
 310 }
 311
 312 static NTSTATUS gensec_gssapi_client_start(struct gensec_security *gensec_security)
 313 {
 314         struct gensec_gssapi_state *gensec_gssapi_state;
 315         struct cli_credentials *creds = gensec_get_credentials(gensec_security);
 316         krb5_error_code ret;
 317         NTSTATUS nt_status;
 318         gss_buffer_desc name_token;
 319         gss_OID name_type;
 320         OM_uint32 maj_stat, min_stat;
 321         const char *hostname = gensec_get_target_hostname(gensec_security);
 322         const char *principal;
 323         struct gssapi_creds_container *gcc;
 324         const char *error_string;
 325
 326         if (!hostname) {
 327                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 328                 return NT_STATUS_INVALID_PARAMETER;
 329         }
 330         if (is_ipaddress(hostname)) {
 331                 DEBUG(2, ("Cannot do GSSAPI to an IP address\n"));
 332                 return NT_STATUS_INVALID_PARAMETER;
 333         }
 334         if (strcmp(hostname, "localhost") == 0) {
 335                 DEBUG(2, ("GSSAPI to 'localhost' does not make sense\n"));
 336                 return NT_STATUS_INVALID_PARAMETER;
 337         }
 338
 339         nt_status = gensec_gssapi_start(gensec_security);
 340         if (!NT_STATUS_IS_OK(nt_status)) {
 341                 return nt_status;
 342         }
 343
 344         gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 345
 346         principal = gensec_get_target_principal(gensec_security);
 347         if (principal && lp_client_use_spnego_principal(gensec_security->settings->lp_ctx)) {
 348                 name_type = GSS_C_NULL_OID;
 349         } else {
 350                 principal = talloc_asprintf(gensec_gssapi_state, "%s/%s@%s",
 351                                             gensec_get_target_service(gensec_security),
 352                                             hostname, lp_realm(gensec_security->settings->lp_ctx));
 353
 354                 name_type = GSS_C_NT_USER_NAME;
 355         }
 356         name_token.value  = discard_const_p(uint8_t, principal);
 357         name_token.length = strlen(principal);
 358
 359
 360         maj_stat = gss_import_name (&min_stat,
 361                                     &name_token,
 362                                     name_type,
 363                                     &gensec_gssapi_state->server_name);
 364         if (maj_stat) {
 365                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 366                           (char *)name_token.value,
 367                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 368                 return NT_STATUS_INVALID_PARAMETER;
 369         }
 370
 371         ret = cli_credentials_get_client_gss_creds(creds,
 372                                                    gensec_security->event_ctx,
 373                                                    gensec_security->settings->lp_ctx, &gcc, &error_string);
 374         switch (ret) {
 375         case 0:
 376                 break;
 377         case KRB5KDC_ERR_PREAUTH_FAILED:
 378                 return NT_STATUS_LOGON_FAILURE;
 379         case KRB5_KDC_UNREACH:
 380                 DEBUG(3, ("Cannot reach a KDC we require to contact %s : %s\n", principal, error_string));
 381                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 382         case KRB5_CC_NOTFOUND:
 383         case KRB5_CC_END:
 384                 DEBUG(3, ("Error preparing credentials we require to contact %s : %s\n", principal, error_string));
 385                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 386         default:
 387                 DEBUG(1, ("Aquiring initiator credentials failed: %s\n", error_string));
 388                 return NT_STATUS_UNSUCCESSFUL;
 389         }
 390
 391         gensec_gssapi_state->client_cred = gcc;
 392         if (!talloc_reference(gensec_gssapi_state, gcc)) {
 393                 return NT_STATUS_NO_MEMORY;
 394         }
 395
 396         return NT_STATUS_OK;
 397 }
 398
 399 static NTSTATUS gensec_gssapi_sasl_client_start(struct gensec_security *gensec_security)
 400 {
 401         NTSTATUS nt_status;
 402         struct gensec_gssapi_state *gensec_gssapi_state;
 403         nt_status = gensec_gssapi_client_start(gensec_security);
 404
 405         if (NT_STATUS_IS_OK(nt_status)) {
 406                 gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 407                 gensec_gssapi_state->sasl = true;
 408         }
 409         return nt_status;
 410 }
 411
 412
 413 /**
 414  * Check if the packet is one for this mechansim
 415  *
 416  * @param gensec_security GENSEC state
 417  * @param in The request, as a DATA_BLOB
 418  * @return Error, INVALID_PARAMETER if it's not a packet for us
 419  *                or NT_STATUS_OK if the packet is ok.
 420  */
 421
 422 static NTSTATUS gensec_gssapi_magic(struct gensec_security *gensec_security,
 423                                     const DATA_BLOB *in)
 424 {
 425         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 426                 return NT_STATUS_OK;
 427         } else {
 428                 return NT_STATUS_INVALID_PARAMETER;
 429         }
 430 }
 431
 432
 433 /**
 434  * Next state function for the GSSAPI GENSEC mechanism
 435  *
 436  * @param gensec_gssapi_state GSSAPI State
 437  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 438  * @param in The request, as a DATA_BLOB
 439  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 440  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 441  *                or NT_STATUS_OK if the user is authenticated.
 442  */
 443
 444 static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 445                                    TALLOC_CTX *out_mem_ctx,
 446                                    const DATA_BLOB in, DATA_BLOB *out)
 447 {
 448         struct gensec_gssapi_state *gensec_gssapi_state
 449                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 450         NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
 451         OM_uint32 maj_stat, min_stat;
 452         OM_uint32 min_stat2;
 453         gss_buffer_desc input_token, output_token;
 454         gss_OID gss_oid_p = NULL;
 455         input_token.length = in.length;
 456         input_token.value = in.data;
 457
 458         switch (gensec_gssapi_state->sasl_state) {
 459         case STAGE_GSS_NEG:
 460         {
 461                 switch (gensec_security->gensec_role) {
 462                 case GENSEC_CLIENT:
 463                 {
 464                         maj_stat = gss_init_sec_context(&min_stat,
 465                                                         gensec_gssapi_state->client_cred->creds,
 466                                                         &gensec_gssapi_state->gssapi_context,
 467                                                         gensec_gssapi_state->server_name,
 468                                                         gensec_gssapi_state->gss_oid,
 469                                                         gensec_gssapi_state->want_flags,
 470                                                         0,
 471                                                         gensec_gssapi_state->input_chan_bindings,
 472                                                         &input_token,
 473                                                         &gss_oid_p,
 474                                                         &output_token,
 475                                                         &gensec_gssapi_state->got_flags, /* ret flags */
 476                                                         NULL);
 477                         if (gss_oid_p) {
 478                                 gensec_gssapi_state->gss_oid = gss_oid_p;
 479                         }
 480                         break;
 481                 }
 482                 case GENSEC_SERVER:
 483                 {
 484                         maj_stat = gss_accept_sec_context(&min_stat,
 485                                                           &gensec_gssapi_state->gssapi_context,
 486                                                           gensec_gssapi_state->server_cred->creds,
 487                                                           &input_token,
 488                                                           gensec_gssapi_state->input_chan_bindings,
 489                                                           &gensec_gssapi_state->client_name,
 490                                                           &gss_oid_p,
 491                                                           &output_token,
 492                                                           &gensec_gssapi_state->got_flags,
 493                                                           NULL,
 494                                                           &gensec_gssapi_state->delegated_cred_handle);
 495                         if (gss_oid_p) {
 496                                 gensec_gssapi_state->gss_oid = gss_oid_p;
 497                         }
 498                         break;
 499                 }
 500                 default:
 501                         return NT_STATUS_INVALID_PARAMETER;
 502
 503                 }
 504
 505                 gensec_gssapi_state->gss_exchange_count++;
 506
 507                 if (maj_stat == GSS_S_COMPLETE) {
 508                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 509                         gss_release_buffer(&min_stat2, &output_token);
 510
 511                         if (gensec_gssapi_state->got_flags & GSS_C_DELEG_FLAG) {
 512                                 DEBUG(5, ("gensec_gssapi: credentials were delegated\n"));
 513                         } else {
 514                                 DEBUG(5, ("gensec_gssapi: NO credentials were delegated\n"));
 515                         }
 516
 517                         /* We may have been invoked as SASL, so there
 518                          * is more work to do */
 519                         if (gensec_gssapi_state->sasl) {
 520                                 /* Due to a very subtle interaction
 521                                  * with SASL and the LDAP libs, we
 522                                  * must ensure the data pointer is
 523                                  * != NULL, but the length is 0.
 524                                  *
 525                                  * This ensures we send a 'zero
 526                                  * length' (rather than NULL) response
 527                                  */
 528
 529                                 if (!out->data) {
 530                                         out->data = (uint8_t *)talloc_strdup(out_mem_ctx, "\0");
 531                                 }
 532
 533                                 gensec_gssapi_state->sasl_state = STAGE_SASL_SSF_NEG;
 534                                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 535                         } else {
 536                                 gensec_gssapi_state->sasl_state = STAGE_DONE;
 537
 538                                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 539                                         DEBUG(5, ("GSSAPI Connection will be cryptographicly sealed\n"));
 540                                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 541                                         DEBUG(5, ("GSSAPI Connection will be cryptographicly signed\n"));
 542                                 } else {
 543                                         DEBUG(5, ("GSSAPI Connection will have no cryptographic protection\n"));
 544                                 }
 545
 546                                 return NT_STATUS_OK;
 547                         }
 548                 } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 549                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 550                         gss_release_buffer(&min_stat2, &output_token);
 551
 552                         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 553                 } else if (gss_oid_equal(gensec_gssapi_state->gss_oid, gss_mech_krb5)) {
 554                         switch (min_stat) {
 555                         case KRB5_KDC_UNREACH:
 556                                 DEBUG(3, ("Cannot reach a KDC we require: %s\n",
 557                                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 558                                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 559                         case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 560                                 DEBUG(3, ("Server is not registered with our KDC: %s\n",
 561                                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 562                                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 563                         case KRB5KRB_AP_ERR_MSG_TYPE:
 564                                 /* garbage input, possibly from the auto-mech detection */
 565                                 return NT_STATUS_INVALID_PARAMETER;
 566                         default:
 567                                 DEBUG(1, ("GSS Update(krb5)(%d) Update failed: %s\n",
 568                                           gensec_gssapi_state->gss_exchange_count,
 569                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 570                                 return nt_status;
 571                         }
 572                 } else {
 573                         DEBUG(1, ("GSS Update(%d) failed: %s\n",
 574                                   gensec_gssapi_state->gss_exchange_count,
 575                                   gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 576                         return nt_status;
 577                 }
 578                 break;
 579         }
 580
 581         /* These last two stages are only done if we were invoked as SASL */
 582         case STAGE_SASL_SSF_NEG:
 583         {
 584                 switch (gensec_security->gensec_role) {
 585                 case GENSEC_CLIENT:
 586                 {
 587                         uint8_t maxlength_proposed[4];
 588                         uint8_t maxlength_accepted[4];
 589                         uint8_t security_supported;
 590                         int conf_state;
 591                         gss_qop_t qop_state;
 592                         input_token.length = in.length;
 593                         input_token.value = in.data;
 594
 595                         /* As a client, we have just send a
 596                          * zero-length blob to the server (after the
 597                          * normal GSSAPI exchange), and it has replied
 598                          * with it's SASL negotiation */
 599
 600                         maj_stat = gss_unwrap(&min_stat,
 601                                               gensec_gssapi_state->gssapi_context,
 602                                               &input_token,
 603                                               &output_token,
 604                                               &conf_state,
 605                                               &qop_state);
 606                         if (GSS_ERROR(maj_stat)) {
 607                                 DEBUG(1, ("gensec_gssapi_update: GSS UnWrap of SASL protection negotiation failed: %s\n",
 608                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 609                                 return NT_STATUS_ACCESS_DENIED;
 610                         }
 611
 612                         if (output_token.length < 4) {
 613                                 return NT_STATUS_INVALID_PARAMETER;
 614                         }
 615
 616                         memcpy(maxlength_proposed, output_token.value, 4);
 617                         gss_release_buffer(&min_stat, &output_token);
 618
 619                         /* first byte is the proposed security */
 620                         security_supported = maxlength_proposed[0];
 621                         maxlength_proposed[0] = '\0';
 622
 623                         /* Rest is the proposed max wrap length */
 624                         gensec_gssapi_state->max_wrap_buf_size = MIN(RIVAL(maxlength_proposed, 0),
 625                                                                      gensec_gssapi_state->max_wrap_buf_size);
 626                         gensec_gssapi_state->sasl_protection = 0;
 627                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 628                                 if (security_supported & NEG_SEAL) {
 629                                         gensec_gssapi_state->sasl_protection |= NEG_SEAL;
 630                                 }
 631                         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 632                                 if (security_supported & NEG_SIGN) {
 633                                         gensec_gssapi_state->sasl_protection |= NEG_SIGN;
 634                                 }
 635                         } else if (security_supported & NEG_NONE) {
 636                                 gensec_gssapi_state->sasl_protection |= NEG_NONE;
 637                         } else {
 638                                 DEBUG(1, ("Remote server does not support unprotected connections"));
 639                                 return NT_STATUS_ACCESS_DENIED;
 640                         }
 641
 642                         /* Send back the negotiated max length */
 643
 644                         RSIVAL(maxlength_accepted, 0, gensec_gssapi_state->max_wrap_buf_size);
 645
 646                         maxlength_accepted[0] = gensec_gssapi_state->sasl_protection;
 647
 648                         input_token.value = maxlength_accepted;
 649                         input_token.length = sizeof(maxlength_accepted);
 650
 651                         maj_stat = gss_wrap(&min_stat,
 652                                             gensec_gssapi_state->gssapi_context,
 653                                             false,
 654                                             GSS_C_QOP_DEFAULT,
 655                                             &input_token,
 656                                             &conf_state,
 657                                             &output_token);
 658                         if (GSS_ERROR(maj_stat)) {
 659                                 DEBUG(1, ("GSS Update(SSF_NEG): GSS Wrap failed: %s\n",
 660                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 661                                 return NT_STATUS_ACCESS_DENIED;
 662                         }
 663
 664                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 665                         gss_release_buffer(&min_stat, &output_token);
 666
 667                         /* quirk:  This changes the value that gensec_have_feature returns, to be that after SASL negotiation */
 668                         gensec_gssapi_state->sasl_state = STAGE_DONE;
 669
 670                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 671                                 DEBUG(3, ("SASL/GSSAPI Connection to server will be cryptographicly sealed\n"));
 672                         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 673                                 DEBUG(3, ("SASL/GSSAPI Connection to server will be cryptographicly signed\n"));
 674                         } else {
 675                                 DEBUG(3, ("SASL/GSSAPI Connection to server will have no cryptographicly protection\n"));
 676                         }
 677
 678                         return NT_STATUS_OK;
 679                 }
 680                 case GENSEC_SERVER:
 681                 {
 682                         uint8_t maxlength_proposed[4];
 683                         uint8_t security_supported = 0x0;
 684                         int conf_state;
 685
 686                         /* As a server, we have just been sent a zero-length blob (note this, but it isn't fatal) */
 687                         if (in.length != 0) {
 688                                 DEBUG(1, ("SASL/GSSAPI: client sent non-zero length starting SASL negotiation!\n"));
 689                         }
 690
 691                         /* Give the client some idea what we will support */
 692
 693                         RSIVAL(maxlength_proposed, 0, gensec_gssapi_state->max_wrap_buf_size);
 694                         /* first byte is the proposed security */
 695                         maxlength_proposed[0] = '\0';
 696
 697                         gensec_gssapi_state->sasl_protection = 0;
 698                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 699                                 security_supported |= NEG_SEAL;
 700                         }
 701                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 702                                 security_supported |= NEG_SIGN;
 703                         }
 704                         if (security_supported == 0) {
 705                                 /* If we don't support anything, this must be 0 */
 706                                 RSIVAL(maxlength_proposed, 0, 0x0);
 707                         }
 708
 709                         /* TODO:  We may not wish to support this */
 710                         security_supported |= NEG_NONE;
 711                         maxlength_proposed[0] = security_supported;
 712
 713                         input_token.value = maxlength_proposed;
 714                         input_token.length = sizeof(maxlength_proposed);
 715
 716                         maj_stat = gss_wrap(&min_stat,
 717                                             gensec_gssapi_state->gssapi_context,
 718                                             false,
 719                                             GSS_C_QOP_DEFAULT,
 720                                             &input_token,
 721                                             &conf_state,
 722                                             &output_token);
 723                         if (GSS_ERROR(maj_stat)) {
 724                                 DEBUG(1, ("GSS Update(SSF_NEG): GSS Wrap failed: %s\n",
 725                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 726                                 return NT_STATUS_ACCESS_DENIED;
 727                         }
 728
 729                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 730                         gss_release_buffer(&min_stat, &output_token);
 731
 732                         gensec_gssapi_state->sasl_state = STAGE_SASL_SSF_ACCEPT;
 733                         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 734                 }
 735                 default:
 736                         return NT_STATUS_INVALID_PARAMETER;
 737
 738                 }
 739         }
 740         /* This is s server-only stage */
 741         case STAGE_SASL_SSF_ACCEPT:
 742         {
 743                 uint8_t maxlength_accepted[4];
 744                 uint8_t security_accepted;
 745                 int conf_state;
 746                 gss_qop_t qop_state;
 747                 input_token.length = in.length;
 748                 input_token.value = in.data;
 749
 750                 maj_stat = gss_unwrap(&min_stat,
 751                                       gensec_gssapi_state->gssapi_context,
 752                                       &input_token,
 753                                       &output_token,
 754                                       &conf_state,
 755                                       &qop_state);
 756                 if (GSS_ERROR(maj_stat)) {
 757                         DEBUG(1, ("gensec_gssapi_update: GSS UnWrap of SASL protection negotiation failed: %s\n",
 758                                   gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 759                         return NT_STATUS_ACCESS_DENIED;
 760                 }
 761
 762                 if (output_token.length < 4) {
 763                         return NT_STATUS_INVALID_PARAMETER;
 764                 }
 765
 766                 memcpy(maxlength_accepted, output_token.value, 4);
 767                 gss_release_buffer(&min_stat, &output_token);
 768
 769                 /* first byte is the proposed security */
 770                 security_accepted = maxlength_accepted[0];
 771                 maxlength_accepted[0] = '\0';
 772
 773                 /* Rest is the proposed max wrap length */
 774                 gensec_gssapi_state->max_wrap_buf_size = MIN(RIVAL(maxlength_accepted, 0),
 775                                                              gensec_gssapi_state->max_wrap_buf_size);
 776
 777                 gensec_gssapi_state->sasl_protection = 0;
 778                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 779                         if (security_accepted & NEG_SEAL) {
 780                                 gensec_gssapi_state->sasl_protection |= NEG_SEAL;
 781                         }
 782                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 783                         if (security_accepted & NEG_SIGN) {
 784                                 gensec_gssapi_state->sasl_protection |= NEG_SIGN;
 785                         }
 786                 } else if (security_accepted & NEG_NONE) {
 787                         gensec_gssapi_state->sasl_protection |= NEG_NONE;
 788                 } else {
 789                         DEBUG(1, ("Remote client does not support unprotected connections, but we failed to negotiate anything better"));
 790                         return NT_STATUS_ACCESS_DENIED;
 791                 }
 792
 793                 /* quirk:  This changes the value that gensec_have_feature returns, to be that after SASL negotiation */
 794                 gensec_gssapi_state->sasl_state = STAGE_DONE;
 795                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 796                         DEBUG(5, ("SASL/GSSAPI Connection from client will be cryptographicly sealed\n"));
 797                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 798                         DEBUG(5, ("SASL/GSSAPI Connection from client will be cryptographicly signed\n"));
 799                 } else {
 800                         DEBUG(5, ("SASL/GSSAPI Connection from client will have no cryptographic protection\n"));
 801                 }
 802
 803                 *out = data_blob(NULL, 0);
 804                 return NT_STATUS_OK;
 805         }
 806         default:
 807                 return NT_STATUS_INVALID_PARAMETER;
 808         }
 809 }
 810
 811 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 812                                    TALLOC_CTX *mem_ctx,
 813                                    const DATA_BLOB *in,
 814                                    DATA_BLOB *out)
 815 {
 816         struct gensec_gssapi_state *gensec_gssapi_state
 817                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 818         OM_uint32 maj_stat, min_stat;
 819         gss_buffer_desc input_token, output_token;
 820         int conf_state;
 821         input_token.length = in->length;
 822         input_token.value = in->data;
 823
 824         maj_stat = gss_wrap(&min_stat,
 825                             gensec_gssapi_state->gssapi_context,
 826                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 827                             GSS_C_QOP_DEFAULT,
 828                             &input_token,
 829                             &conf_state,
 830                             &output_token);
 831         if (GSS_ERROR(maj_stat)) {
 832                 DEBUG(1, ("gensec_gssapi_wrap: GSS Wrap failed: %s\n",
 833                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 834                 return NT_STATUS_ACCESS_DENIED;
 835         }
 836
 837         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 838         gss_release_buffer(&min_stat, &output_token);
 839
 840         if (gensec_gssapi_state->sasl) {
 841                 size_t max_wrapped_size = gensec_gssapi_max_wrapped_size(gensec_security);
 842                 if (max_wrapped_size < out->length) {
 843                         DEBUG(1, ("gensec_gssapi_wrap: when wrapped, INPUT data (%u) is grew to be larger than SASL negotiated maximum output size (%u > %u)\n",
 844                                   (unsigned)in->length,
 845                                   (unsigned)out->length,
 846                                   (unsigned int)max_wrapped_size));
 847                         return NT_STATUS_INVALID_PARAMETER;
 848                 }
 849         }
 850
 851         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 852             && !conf_state) {
 853                 return NT_STATUS_ACCESS_DENIED;
 854         }
 855         return NT_STATUS_OK;
 856 }
 857
 858 static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 859                                      TALLOC_CTX *mem_ctx,
 860                                      const DATA_BLOB *in,
 861                                      DATA_BLOB *out)
 862 {
 863         struct gensec_gssapi_state *gensec_gssapi_state
 864                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 865         OM_uint32 maj_stat, min_stat;
 866         gss_buffer_desc input_token, output_token;
 867         int conf_state;
 868         gss_qop_t qop_state;
 869         input_token.length = in->length;
 870         input_token.value = in->data;
 871
 872         if (gensec_gssapi_state->sasl) {
 873                 size_t max_wrapped_size = gensec_gssapi_max_wrapped_size(gensec_security);
 874                 if (max_wrapped_size < in->length) {
 875                         DEBUG(1, ("gensec_gssapi_unwrap: WRAPPED data is larger than SASL negotiated maximum size\n"));
 876                         return NT_STATUS_INVALID_PARAMETER;
 877                 }
 878         }
 879
 880         maj_stat = gss_unwrap(&min_stat,
 881                               gensec_gssapi_state->gssapi_context,
 882                               &input_token,
 883                               &output_token,
 884                               &conf_state,
 885                               &qop_state);
 886         if (GSS_ERROR(maj_stat)) {
 887                 DEBUG(1, ("gensec_gssapi_unwrap: GSS UnWrap failed: %s\n",
 888                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 889                 return NT_STATUS_ACCESS_DENIED;
 890         }
 891
 892         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 893         gss_release_buffer(&min_stat, &output_token);
 894
 895         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 896             && !conf_state) {
 897                 return NT_STATUS_ACCESS_DENIED;
 898         }
 899         return NT_STATUS_OK;
 900 }
 901
 902 /* Find out the maximum input size negotiated on this connection */
 903
 904 static size_t gensec_gssapi_max_input_size(struct gensec_security *gensec_security)
 905 {
 906         struct gensec_gssapi_state *gensec_gssapi_state
 907                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 908         OM_uint32 maj_stat, min_stat;
 909         OM_uint32 max_input_size;
 910
 911         maj_stat = gss_wrap_size_limit(&min_stat,
 912                                        gensec_gssapi_state->gssapi_context,
 913                                        gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 914                                        GSS_C_QOP_DEFAULT,
 915                                        gensec_gssapi_state->max_wrap_buf_size,
 916                                        &max_input_size);
 917         if (GSS_ERROR(maj_stat)) {
 918                 TALLOC_CTX *mem_ctx = talloc_new(NULL);
 919                 DEBUG(1, ("gensec_gssapi_max_input_size: determinaing signature size with gss_wrap_size_limit failed: %s\n",
 920                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 921                 talloc_free(mem_ctx);
 922                 return 0;
 923         }
 924
 925         return max_input_size;
 926 }
 927
 928 /* Find out the maximum output size negotiated on this connection */
 929 static size_t gensec_gssapi_max_wrapped_size(struct gensec_security *gensec_security)
 930 {
 931         struct gensec_gssapi_state *gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);;
 932         return gensec_gssapi_state->max_wrap_buf_size;
 933 }
 934
 935 static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_security,
 936                                           TALLOC_CTX *mem_ctx,
 937                                           uint8_t *data, size_t length,
 938                                           const uint8_t *whole_pdu, size_t pdu_length,
 939                                           DATA_BLOB *sig)
 940 {
 941         struct gensec_gssapi_state *gensec_gssapi_state
 942                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 943         OM_uint32 maj_stat, min_stat;
 944         gss_buffer_desc input_token, output_token;
 945         int conf_state;
 946         ssize_t sig_length;
 947
 948         input_token.length = length;
 949         input_token.value = data;
 950
 951         maj_stat = gss_wrap(&min_stat,
 952                             gensec_gssapi_state->gssapi_context,
 953                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 954                             GSS_C_QOP_DEFAULT,
 955                             &input_token,
 956                             &conf_state,
 957                             &output_token);
 958         if (GSS_ERROR(maj_stat)) {
 959                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap failed: %s\n",
 960                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 961                 return NT_STATUS_ACCESS_DENIED;
 962         }
 963
 964         if (output_token.length < input_token.length) {
 965                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap length [%ld] *less* than caller length [%ld]\n",
 966                           (long)output_token.length, (long)length));
 967                 return NT_STATUS_INTERNAL_ERROR;
 968         }
 969         sig_length = output_token.length - input_token.length;
 970
 971         memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);
 972         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 973
 974         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 975         dump_data_pw("gensec_gssapi_seal_packet: clear\n", data, length);
 976         dump_data_pw("gensec_gssapi_seal_packet: sealed\n", ((uint8_t *)output_token.value) + sig_length, output_token.length - sig_length);
 977
 978         gss_release_buffer(&min_stat, &output_token);
 979
 980         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 981             && !conf_state) {
 982                 return NT_STATUS_ACCESS_DENIED;
 983         }
 984         return NT_STATUS_OK;
 985 }
 986
 987 static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_security,
 988                                             TALLOC_CTX *mem_ctx,
 989                                             uint8_t *data, size_t length,
 990                                             const uint8_t *whole_pdu, size_t pdu_length,
 991                                             const DATA_BLOB *sig)
 992 {
 993         struct gensec_gssapi_state *gensec_gssapi_state
 994                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 995         OM_uint32 maj_stat, min_stat;
 996         gss_buffer_desc input_token, output_token;
 997         int conf_state;
 998         gss_qop_t qop_state;
 999         DATA_BLOB in;
1000
1001         dump_data_pw("gensec_gssapi_unseal_packet: sig\n", sig->data, sig->length);
1002
1003         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
1004
1005         memcpy(in.data, sig->data, sig->length);
1006         memcpy(in.data + sig->length, data, length);
1007
1008         input_token.length = in.length;
1009         input_token.value = in.data;
1010
1011         maj_stat = gss_unwrap(&min_stat,
1012                               gensec_gssapi_state->gssapi_context,
1013                               &input_token,
1014                               &output_token,
1015                               &conf_state,
1016                               &qop_state);
1017         if (GSS_ERROR(maj_stat)) {
1018                 DEBUG(1, ("gensec_gssapi_unseal_packet: GSS UnWrap failed: %s\n",
1019                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1020                 return NT_STATUS_ACCESS_DENIED;
1021         }
1022
1023         if (output_token.length != length) {
1024                 return NT_STATUS_INTERNAL_ERROR;
1025         }
1026
1027         memcpy(data, output_token.value, length);
1028
1029         gss_release_buffer(&min_stat, &output_token);
1030
1031         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
1032             && !conf_state) {
1033                 return NT_STATUS_ACCESS_DENIED;
1034         }
1035         return NT_STATUS_OK;
1036 }
1037
1038 static NTSTATUS gensec_gssapi_sign_packet(struct gensec_security *gensec_security,
1039                                           TALLOC_CTX *mem_ctx,
1040                                           const uint8_t *data, size_t length,
1041                                           const uint8_t *whole_pdu, size_t pdu_length,
1042                                           DATA_BLOB *sig)
1043 {
1044         struct gensec_gssapi_state *gensec_gssapi_state
1045                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1046         OM_uint32 maj_stat, min_stat;
1047         gss_buffer_desc input_token, output_token;
1048
1049         if (gensec_security->want_features & GENSEC_FEATURE_SIGN_PKT_HEADER) {
1050                 input_token.length = pdu_length;
1051                 input_token.value = discard_const_p(uint8_t *, whole_pdu);
1052         } else {
1053                 input_token.length = length;
1054                 input_token.value = discard_const_p(uint8_t *, data);
1055         }
1056
1057         maj_stat = gss_get_mic(&min_stat,
1058                             gensec_gssapi_state->gssapi_context,
1059                             GSS_C_QOP_DEFAULT,
1060                             &input_token,
1061                             &output_token);
1062         if (GSS_ERROR(maj_stat)) {
1063                 DEBUG(1, ("GSS GetMic failed: %s\n",
1064                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1065                 return NT_STATUS_ACCESS_DENIED;
1066         }
1067
1068         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, output_token.length);
1069
1070         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
1071
1072         gss_release_buffer(&min_stat, &output_token);
1073
1074         return NT_STATUS_OK;
1075 }
1076
1077 static NTSTATUS gensec_gssapi_check_packet(struct gensec_security *gensec_security,
1078                                            TALLOC_CTX *mem_ctx,
1079                                            const uint8_t *data, size_t length,
1080                                            const uint8_t *whole_pdu, size_t pdu_length,
1081                                            const DATA_BLOB *sig)
1082 {
1083         struct gensec_gssapi_state *gensec_gssapi_state
1084                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1085         OM_uint32 maj_stat, min_stat;
1086         gss_buffer_desc input_token;
1087         gss_buffer_desc input_message;
1088         gss_qop_t qop_state;
1089
1090         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
1091
1092         if (gensec_security->want_features & GENSEC_FEATURE_SIGN_PKT_HEADER) {
1093                 input_message.length = pdu_length;
1094                 input_message.value = discard_const(whole_pdu);
1095         } else {
1096                 input_message.length = length;
1097                 input_message.value = discard_const(data);
1098         }
1099
1100         input_token.length = sig->length;
1101         input_token.value = sig->data;
1102
1103         maj_stat = gss_verify_mic(&min_stat,
1104                               gensec_gssapi_state->gssapi_context,
1105                               &input_message,
1106                               &input_token,
1107                               &qop_state);
1108         if (GSS_ERROR(maj_stat)) {
1109                 DEBUG(1, ("GSS VerifyMic failed: %s\n",
1110                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1111                 return NT_STATUS_ACCESS_DENIED;
1112         }
1113
1114         return NT_STATUS_OK;
1115 }
1116
1117 /* Try to figure out what features we actually got on the connection */
1118 static bool gensec_gssapi_have_feature(struct gensec_security *gensec_security,
1119                                        uint32_t feature)
1120 {
1121         struct gensec_gssapi_state *gensec_gssapi_state
1122                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1123         if (feature & GENSEC_FEATURE_SIGN) {
1124                 /* If we are going GSSAPI SASL, then we honour the second negotiation */
1125                 if (gensec_gssapi_state->sasl
1126                     && gensec_gssapi_state->sasl_state == STAGE_DONE) {
1127                         return ((gensec_gssapi_state->sasl_protection & NEG_SIGN)
1128                                 && (gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG));
1129                 }
1130                 return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
1131         }
1132         if (feature & GENSEC_FEATURE_SEAL) {
1133                 /* If we are going GSSAPI SASL, then we honour the second negotiation */
1134                 if (gensec_gssapi_state->sasl
1135                     && gensec_gssapi_state->sasl_state == STAGE_DONE) {
1136                         return ((gensec_gssapi_state->sasl_protection & NEG_SEAL)
1137                                  && (gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG));
1138                 }
1139                 return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
1140         }
1141         if (feature & GENSEC_FEATURE_SESSION_KEY) {
1142                 /* Only for GSSAPI/Krb5 */
1143                 if (gss_oid_equal(gensec_gssapi_state->gss_oid, gss_mech_krb5)) {
1144                         return true;
1145                 }
1146         }
1147         if (feature & GENSEC_FEATURE_DCE_STYLE) {
1148                 return gensec_gssapi_state->got_flags & GSS_C_DCE_STYLE;
1149         }
1150         if (feature & GENSEC_FEATURE_NEW_SPNEGO) {
1151                 NTSTATUS status;
1152
1153                 if (!(gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG)) {
1154                         return false;
1155                 }
1156
1157                 if (gensec_setting_bool(gensec_security->settings, "gensec_gssapi", "force_new_spnego", false)) {
1158                         return true;
1159                 }
1160                 if (gensec_setting_bool(gensec_security->settings, "gensec_gssapi", "disable_new_spnego", false)) {
1161                         return false;
1162                 }
1163
1164                 status = gensec_gssapi_init_lucid(gensec_gssapi_state);
1165                 if (!NT_STATUS_IS_OK(status)) {
1166                         return false;
1167                 }
1168
1169                 if (gensec_gssapi_state->lucid->protocol == 1) {
1170                         return true;
1171                 }
1172
1173                 return false;
1174         }
1175         /* We can always do async (rather than strict request/reply) packets.  */
1176         if (feature & GENSEC_FEATURE_ASYNC_REPLIES) {
1177                 return true;
1178         }
1179         return false;
1180 }
1181
1182 /*
1183  * Extract the 'sesssion key' needed by SMB signing and ncacn_np
1184  * (for encrypting some passwords).
1185  *
1186  * This breaks all the abstractions, but what do you expect...
1187  */
1188 static NTSTATUS gensec_gssapi_session_key(struct gensec_security *gensec_security,
1189                                           DATA_BLOB *session_key)
1190 {
1191         struct gensec_gssapi_state *gensec_gssapi_state
1192                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1193         OM_uint32 maj_stat, min_stat;
1194         krb5_keyblock *subkey;
1195
1196         if (gensec_gssapi_state->sasl_state != STAGE_DONE) {
1197                 return NT_STATUS_NO_USER_SESSION_KEY;
1198         }
1199
1200         if (gensec_gssapi_state->session_key.data) {
1201                 *session_key = gensec_gssapi_state->session_key;
1202                 return NT_STATUS_OK;
1203         }
1204
1205         maj_stat = gsskrb5_get_subkey(&min_stat,
1206                                       gensec_gssapi_state->gssapi_context,
1207                                       &subkey);
1208         if (maj_stat != 0) {
1209                 DEBUG(1, ("NO session key for this mech\n"));
1210                 return NT_STATUS_NO_USER_SESSION_KEY;
1211         }
1212
1213         DEBUG(10, ("Got KRB5 session key of length %d%s\n",
1214                    (int)KRB5_KEY_LENGTH(subkey),
1215                    (gensec_gssapi_state->sasl_state == STAGE_DONE)?" (done)":""));
1216         *session_key = data_blob_talloc(gensec_gssapi_state,
1217                                         KRB5_KEY_DATA(subkey), KRB5_KEY_LENGTH(subkey));
1218         krb5_free_keyblock(gensec_gssapi_state->smb_krb5_context->krb5_context, subkey);
1219         gensec_gssapi_state->session_key = *session_key;
1220         dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
1221
1222         return NT_STATUS_OK;
1223 }
1224
1225 /* Get some basic (and authorization) information about the user on
1226  * this session.  This uses either the PAC (if present) or a local
1227  * database lookup */
1228 static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_security,
1229                                            struct auth_session_info **_session_info)
1230 {
1231         NTSTATUS nt_status;
1232         TALLOC_CTX *mem_ctx;
1233         struct gensec_gssapi_state *gensec_gssapi_state
1234                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1235         struct auth_serversupplied_info *server_info = NULL;
1236         struct auth_session_info *session_info = NULL;
1237         OM_uint32 maj_stat, min_stat;
1238         gss_buffer_desc pac;
1239         DATA_BLOB pac_blob;
1240
1241         if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
1242             || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
1243                        gensec_gssapi_state->gss_oid->length) != 0)) {
1244                 DEBUG(1, ("NO session info available for this mech\n"));
1245                 return NT_STATUS_INVALID_PARAMETER;
1246         }
1247
1248         mem_ctx = talloc_named(gensec_gssapi_state, 0, "gensec_gssapi_session_info context");
1249         NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
1250
1251         maj_stat = gsskrb5_extract_authz_data_from_sec_context(&min_stat,
1252                                                                gensec_gssapi_state->gssapi_context,
1253                                                                KRB5_AUTHDATA_WIN2K_PAC,
1254                                                                &pac);
1255
1256
1257         if (maj_stat == 0) {
1258                 pac_blob = data_blob_talloc(mem_ctx, pac.value, pac.length);
1259                 gss_release_buffer(&min_stat, &pac);
1260
1261         } else {
1262                 pac_blob = data_blob(NULL, 0);
1263         }
1264
1265         /* IF we have the PAC - otherwise we need to get this
1266          * data from elsewere - local ldb, or (TODO) lookup of some
1267          * kind...
1268          */
1269         if (pac_blob.length) {
1270                 nt_status = kerberos_pac_blob_to_server_info(mem_ctx,
1271                                                              gensec_security->settings->iconv_convenience,
1272                                                              pac_blob,
1273                                                              gensec_gssapi_state->smb_krb5_context->krb5_context,
1274                                                              &server_info);
1275                 if (!NT_STATUS_IS_OK(nt_status)) {
1276                         talloc_free(mem_ctx);
1277                         return nt_status;
1278                 }
1279         } else {
1280                 gss_buffer_desc name_token;
1281                 char *principal_string;
1282
1283                 maj_stat = gss_display_name (&min_stat,
1284                                              gensec_gssapi_state->client_name,
1285                                              &name_token,
1286                                              NULL);
1287                 if (GSS_ERROR(maj_stat)) {
1288                         DEBUG(1, ("GSS display_name failed: %s\n",
1289                                   gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1290                         talloc_free(mem_ctx);
1291                         return NT_STATUS_FOOBAR;
1292                 }
1293
1294                 principal_string = talloc_strndup(mem_ctx,
1295                                                   (const char *)name_token.value,
1296                                                   name_token.length);
1297
1298                 gss_release_buffer(&min_stat, &name_token);
1299
1300                 if (!principal_string) {
1301                         talloc_free(mem_ctx);
1302                         return NT_STATUS_NO_MEMORY;
1303                 }
1304
1305                 if (gensec_security->auth_context &&
1306                     !gensec_setting_bool(gensec_security->settings, "gensec", "require_pac", false)) {
1307                         DEBUG(1, ("Unable to find PAC, resorting to local user lookup: %s\n",
1308                                   gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1309                         nt_status = gensec_security->auth_context->get_server_info_principal(mem_ctx,
1310                                                                                              gensec_security->auth_context,
1311                                                                                              principal_string,
1312                                                                                              &server_info);
1313
1314                         if (!NT_STATUS_IS_OK(nt_status)) {
1315                                 talloc_free(mem_ctx);
1316                                 return nt_status;
1317                         }
1318                 } else {
1319                         DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access: %s\n",
1320                                   principal_string,
1321                                   gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1322                         return NT_STATUS_ACCESS_DENIED;
1323                 }
1324         }
1325
1326         /* references the server_info into the session_info */
1327         nt_status = gensec_generate_session_info(mem_ctx, gensec_security,
1328                                                  server_info, &session_info);
1329         if (!NT_STATUS_IS_OK(nt_status)) {
1330                 talloc_free(mem_ctx);
1331                 return nt_status;
1332         }
1333
1334         nt_status = gensec_gssapi_session_key(gensec_security, &session_info->session_key);
1335         if (!NT_STATUS_IS_OK(nt_status)) {
1336                 talloc_free(mem_ctx);
1337                 return nt_status;
1338         }
1339
1340         if (!(gensec_gssapi_state->got_flags & GSS_C_DELEG_FLAG)) {
1341                 DEBUG(10, ("gensec_gssapi: NO delegated credentials supplied by client\n"));
1342         } else {
1343                 krb5_error_code ret;
1344                 const char *error_string;
1345
1346                 DEBUG(10, ("gensec_gssapi: delegated credentials supplied by client\n"));
1347                 session_info->credentials = cli_credentials_init(session_info);
1348                 if (!session_info->credentials) {
1349                         talloc_free(mem_ctx);
1350                         return NT_STATUS_NO_MEMORY;
1351                 }
1352
1353                 cli_credentials_set_conf(session_info->credentials, gensec_security->settings->lp_ctx);
1354                 /* Just so we don't segfault trying to get at a username */
1355                 cli_credentials_set_anonymous(session_info->credentials);
1356
1357                 ret = cli_credentials_set_client_gss_creds(session_info->credentials,
1358                                                            gensec_security->event_ctx,
1359                                                            gensec_security->settings->lp_ctx,
1360                                                            gensec_gssapi_state->delegated_cred_handle,
1361                                                            CRED_SPECIFIED, &error_string);
1362                 if (ret) {
1363                         talloc_free(mem_ctx);
1364                         DEBUG(2,("Failed to get gss creds: %s\n", error_string));
1365                         return NT_STATUS_NO_MEMORY;
1366                 }
1367
1368                 /* This credential handle isn't useful for password authentication, so ensure nobody tries to do that */
1369                 cli_credentials_set_kerberos_state(session_info->credentials, CRED_MUST_USE_KERBEROS);
1370
1371                 /* It has been taken from this place... */
1372                 gensec_gssapi_state->delegated_cred_handle = GSS_C_NO_CREDENTIAL;
1373         }
1374         talloc_steal(gensec_gssapi_state, session_info);
1375         talloc_free(mem_ctx);
1376         *_session_info = session_info;
1377
1378         return NT_STATUS_OK;
1379 }
1380
1381 static size_t gensec_gssapi_sig_size(struct gensec_security *gensec_security, size_t data_size)
1382 {
1383         struct gensec_gssapi_state *gensec_gssapi_state
1384                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1385         NTSTATUS status;
1386
1387         if (gensec_gssapi_state->sig_size) {
1388                 return gensec_gssapi_state->sig_size;
1389         }
1390
1391         if (gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG) {
1392                 gensec_gssapi_state->sig_size = 45;
1393         } else {
1394                 gensec_gssapi_state->sig_size = 37;
1395         }
1396
1397         status = gensec_gssapi_init_lucid(gensec_gssapi_state);
1398         if (!NT_STATUS_IS_OK(status)) {
1399                 return gensec_gssapi_state->sig_size;
1400         }
1401
1402         if (gensec_gssapi_state->lucid->protocol == 1) {
1403                 if (gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG) {
1404                         /*
1405                          * TODO: windows uses 76 here, but we don't know
1406                          *       gss_wrap works with aes keys yet
1407                          */
1408                         gensec_gssapi_state->sig_size = 76;
1409                 } else {
1410                         gensec_gssapi_state->sig_size = 28;
1411                 }
1412         } else if (gensec_gssapi_state->lucid->protocol == 0) {
1413                 switch (gensec_gssapi_state->lucid->rfc1964_kd.ctx_key.type) {
1414                 case KEYTYPE_DES:
1415                 case KEYTYPE_ARCFOUR:
1416                 case KEYTYPE_ARCFOUR_56:
1417                         if (gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG) {
1418                                 gensec_gssapi_state->sig_size = 45;
1419                         } else {
1420                                 gensec_gssapi_state->sig_size = 37;
1421                         }
1422                         break;
1423                 case KEYTYPE_DES3:
1424                         if (gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG) {
1425                                 gensec_gssapi_state->sig_size = 57;
1426                         } else {
1427                                 gensec_gssapi_state->sig_size = 49;
1428                         }
1429                         break;
1430                 }
1431         }
1432
1433         return gensec_gssapi_state->sig_size;
1434 }
1435
1436 static const char *gensec_gssapi_krb5_oids[] = {
1437         GENSEC_OID_KERBEROS5_OLD,
1438         GENSEC_OID_KERBEROS5,
1439         NULL
1440 };
1441
1442 static const char *gensec_gssapi_spnego_oids[] = {
1443         GENSEC_OID_SPNEGO,
1444         NULL
1445 };
1446
1447 /* As a server, this could in theory accept any GSSAPI mech */
1448 static const struct gensec_security_ops gensec_gssapi_spnego_security_ops = {
1449         .name           = "gssapi_spnego",
1450         .sasl_name      = "GSS-SPNEGO",
1451         .auth_type      = DCERPC_AUTH_TYPE_SPNEGO,
1452         .oid            = gensec_gssapi_spnego_oids,
1453         .client_start   = gensec_gssapi_client_start,
1454         .server_start   = gensec_gssapi_server_start,
1455         .magic          = gensec_gssapi_magic,
1456         .update         = gensec_gssapi_update,
1457         .session_key    = gensec_gssapi_session_key,
1458         .session_info   = gensec_gssapi_session_info,
1459         .sign_packet    = gensec_gssapi_sign_packet,
1460         .check_packet   = gensec_gssapi_check_packet,
1461         .seal_packet    = gensec_gssapi_seal_packet,
1462         .unseal_packet  = gensec_gssapi_unseal_packet,
1463         .wrap           = gensec_gssapi_wrap,
1464         .unwrap         = gensec_gssapi_unwrap,
1465         .have_feature   = gensec_gssapi_have_feature,
1466         .enabled        = false,
1467         .kerberos       = true,
1468         .priority       = GENSEC_GSSAPI
1469 };
1470
1471 /* As a server, this could in theory accept any GSSAPI mech */
1472 static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
1473         .name           = "gssapi_krb5",
1474         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
1475         .oid            = gensec_gssapi_krb5_oids,
1476         .client_start   = gensec_gssapi_client_start,
1477         .server_start   = gensec_gssapi_server_start,
1478         .magic          = gensec_gssapi_magic,
1479         .update         = gensec_gssapi_update,
1480         .session_key    = gensec_gssapi_session_key,
1481         .session_info   = gensec_gssapi_session_info,
1482         .sig_size       = gensec_gssapi_sig_size,
1483         .sign_packet    = gensec_gssapi_sign_packet,
1484         .check_packet   = gensec_gssapi_check_packet,
1485         .seal_packet    = gensec_gssapi_seal_packet,
1486         .unseal_packet  = gensec_gssapi_unseal_packet,
1487         .wrap           = gensec_gssapi_wrap,
1488         .unwrap         = gensec_gssapi_unwrap,
1489         .have_feature   = gensec_gssapi_have_feature,
1490         .enabled        = true,
1491         .kerberos       = true,
1492         .priority       = GENSEC_GSSAPI
1493 };
1494
1495 /* As a server, this could in theory accept any GSSAPI mech */
1496 static const struct gensec_security_ops gensec_gssapi_sasl_krb5_security_ops = {
1497         .name             = "gssapi_krb5_sasl",
1498         .sasl_name        = "GSSAPI",
1499         .client_start     = gensec_gssapi_sasl_client_start,
1500         .server_start     = gensec_gssapi_sasl_server_start,
1501         .update           = gensec_gssapi_update,
1502         .session_key      = gensec_gssapi_session_key,
1503         .session_info     = gensec_gssapi_session_info,
1504         .max_input_size   = gensec_gssapi_max_input_size,
1505         .max_wrapped_size = gensec_gssapi_max_wrapped_size,
1506         .wrap             = gensec_gssapi_wrap,
1507         .unwrap           = gensec_gssapi_unwrap,
1508         .have_feature     = gensec_gssapi_have_feature,
1509         .enabled          = true,
1510         .kerberos         = true,
1511         .priority         = GENSEC_GSSAPI
1512 };
1513
1514 _PUBLIC_ NTSTATUS gensec_gssapi_init(void)
1515 {
1516         NTSTATUS ret;
1517
1518         ret = gensec_register(&gensec_gssapi_spnego_security_ops);
1519         if (!NT_STATUS_IS_OK(ret)) {
1520                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1521                         gensec_gssapi_spnego_security_ops.name));
1522                 return ret;
1523         }
1524
1525         ret = gensec_register(&gensec_gssapi_krb5_security_ops);
1526         if (!NT_STATUS_IS_OK(ret)) {
1527                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1528                         gensec_gssapi_krb5_security_ops.name));
1529                 return ret;
1530         }
1531
1532         ret = gensec_register(&gensec_gssapi_sasl_krb5_security_ops);
1533         if (!NT_STATUS_IS_OK(ret)) {
1534                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1535                         gensec_gssapi_sasl_krb5_security_ops.name));
1536                 return ret;
1537         }
1538
1539         return ret;
1540 }