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_security->private_data = gensec_gssapi_state;
 159
 160         gensec_gssapi_state->gssapi_context = GSS_C_NO_CONTEXT;
 161
 162         /* TODO: Fill in channel bindings */
 163         gensec_gssapi_state->input_chan_bindings = GSS_C_NO_CHANNEL_BINDINGS;
 164
 165         gensec_gssapi_state->server_name = GSS_C_NO_NAME;
 166         gensec_gssapi_state->client_name = GSS_C_NO_NAME;
 167
 168         gensec_gssapi_state->want_flags = 0;
 169
 170         if (gensec_setting_bool(gensec_security->settings, "gensec_gssapi", "delegation_by_kdc_policy", true)) {
 171                 gensec_gssapi_state->want_flags |= GSS_C_DELEG_POLICY_FLAG;
 172         }
 173         if (gensec_setting_bool(gensec_security->settings, "gensec_gssapi", "mutual", true)) {
 174                 gensec_gssapi_state->want_flags |= GSS_C_MUTUAL_FLAG;
 175         }
 176         if (gensec_setting_bool(gensec_security->settings, "gensec_gssapi", "delegation", true)) {
 177                 gensec_gssapi_state->want_flags |= GSS_C_DELEG_FLAG;
 178         }
 179         if (gensec_setting_bool(gensec_security->settings, "gensec_gssapi", "replay", true)) {
 180                 gensec_gssapi_state->want_flags |= GSS_C_REPLAY_FLAG;
 181         }
 182         if (gensec_setting_bool(gensec_security->settings, "gensec_gssapi", "sequence", true)) {
 183                 gensec_gssapi_state->want_flags |= GSS_C_SEQUENCE_FLAG;
 184         }
 185
 186         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 187                 gensec_gssapi_state->want_flags |= GSS_C_INTEG_FLAG;
 188         }
 189         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 190                 gensec_gssapi_state->want_flags |= GSS_C_CONF_FLAG;
 191         }
 192         if (gensec_security->want_features & GENSEC_FEATURE_DCE_STYLE) {
 193                 gensec_gssapi_state->want_flags |= GSS_C_DCE_STYLE;
 194         }
 195
 196         gensec_gssapi_state->got_flags = 0;
 197
 198         switch (gensec_security->ops->auth_type) {
 199         case DCERPC_AUTH_TYPE_SPNEGO:
 200                 gensec_gssapi_state->gss_oid = gss_mech_spnego;
 201                 break;
 202         case DCERPC_AUTH_TYPE_KRB5:
 203         default:
 204                 gensec_gssapi_state->gss_oid = gss_mech_krb5;
 205                 break;
 206         }
 207
 208         gensec_gssapi_state->session_key = data_blob(NULL, 0);
 209         gensec_gssapi_state->pac = data_blob(NULL, 0);
 210
 211         ret = smb_krb5_init_context(gensec_gssapi_state,
 212                                     gensec_security->event_ctx,
 213                                     gensec_security->settings->lp_ctx,
 214                                     &gensec_gssapi_state->smb_krb5_context);
 215         if (ret) {
 216                 DEBUG(1,("gensec_krb5_start: krb5_init_context failed (%s)\n",
 217                          error_message(ret)));
 218                 talloc_free(gensec_gssapi_state);
 219                 return NT_STATUS_INTERNAL_ERROR;
 220         }
 221
 222         gensec_gssapi_state->client_cred = NULL;
 223         gensec_gssapi_state->server_cred = NULL;
 224
 225         gensec_gssapi_state->lucid = NULL;
 226
 227         gensec_gssapi_state->delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 228
 229         gensec_gssapi_state->sasl = false;
 230         gensec_gssapi_state->sasl_state = STAGE_GSS_NEG;
 231         gensec_gssapi_state->sasl_protection = 0;
 232
 233         gensec_gssapi_state->max_wrap_buf_size
 234                 = gensec_setting_int(gensec_security->settings, "gensec_gssapi", "max wrap buf size", 65536);
 235         gensec_gssapi_state->gss_exchange_count = 0;
 236         gensec_gssapi_state->sig_size = 0;
 237
 238         talloc_set_destructor(gensec_gssapi_state, gensec_gssapi_destructor);
 239
 240         send_to_kdc.func = smb_krb5_send_and_recv_func;
 241         send_to_kdc.ptr = gensec_security->event_ctx;
 242
 243         ret = gsskrb5_set_send_to_kdc(&send_to_kdc);
 244         if (ret) {
 245                 DEBUG(1,("gensec_krb5_start: gsskrb5_set_send_to_kdc failed\n"));
 246                 talloc_free(gensec_gssapi_state);
 247                 return NT_STATUS_INTERNAL_ERROR;
 248         }
 249
 250         realm = lpcfg_realm(gensec_security->settings->lp_ctx);
 251         if (realm != NULL) {
 252                 ret = gsskrb5_set_default_realm(realm);
 253                 if (ret) {
 254                         DEBUG(1,("gensec_krb5_start: gsskrb5_set_default_realm failed\n"));
 255                         talloc_free(gensec_gssapi_state);
 256                         return NT_STATUS_INTERNAL_ERROR;
 257                 }
 258         }
 259
 260         /* don't do DNS lookups of any kind, it might/will fail for a netbios name */
 261         ret = gsskrb5_set_dns_canonicalize(gensec_setting_bool(gensec_security->settings, "krb5", "set_dns_canonicalize", false));
 262         if (ret) {
 263                 DEBUG(1,("gensec_krb5_start: gsskrb5_set_dns_canonicalize failed\n"));
 264                 talloc_free(gensec_gssapi_state);
 265                 return NT_STATUS_INTERNAL_ERROR;
 266         }
 267
 268         return NT_STATUS_OK;
 269 }
 270
 271 static NTSTATUS gensec_gssapi_server_start(struct gensec_security *gensec_security)
 272 {
 273         NTSTATUS nt_status;
 274         int ret;
 275         struct gensec_gssapi_state *gensec_gssapi_state;
 276         struct cli_credentials *machine_account;
 277         struct gssapi_creds_container *gcc;
 278
 279         nt_status = gensec_gssapi_start(gensec_security);
 280         if (!NT_STATUS_IS_OK(nt_status)) {
 281                 return nt_status;
 282         }
 283
 284         gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 285
 286         machine_account = gensec_get_credentials(gensec_security);
 287
 288         if (!machine_account) {
 289                 DEBUG(3, ("No machine account credentials specified\n"));
 290                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 291         } else {
 292                 ret = cli_credentials_get_server_gss_creds(machine_account,
 293                                                            gensec_security->event_ctx,
 294                                                            gensec_security->settings->lp_ctx, &gcc);
 295                 if (ret) {
 296                         DEBUG(1, ("Aquiring acceptor credentials failed: %s\n",
 297                                   error_message(ret)));
 298                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 299                 }
 300         }
 301
 302         gensec_gssapi_state->server_cred = gcc;
 303         return NT_STATUS_OK;
 304
 305 }
 306
 307 static NTSTATUS gensec_gssapi_sasl_server_start(struct gensec_security *gensec_security)
 308 {
 309         NTSTATUS nt_status;
 310         struct gensec_gssapi_state *gensec_gssapi_state;
 311         nt_status = gensec_gssapi_server_start(gensec_security);
 312
 313         if (NT_STATUS_IS_OK(nt_status)) {
 314                 gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 315                 gensec_gssapi_state->sasl = true;
 316         }
 317         return nt_status;
 318 }
 319
 320 static NTSTATUS gensec_gssapi_client_start(struct gensec_security *gensec_security)
 321 {
 322         struct gensec_gssapi_state *gensec_gssapi_state;
 323         struct cli_credentials *creds = gensec_get_credentials(gensec_security);
 324         krb5_error_code ret;
 325         NTSTATUS nt_status;
 326         gss_buffer_desc name_token;
 327         gss_OID name_type;
 328         OM_uint32 maj_stat, min_stat;
 329         const char *hostname = gensec_get_target_hostname(gensec_security);
 330         const char *principal;
 331         struct gssapi_creds_container *gcc;
 332         const char *error_string;
 333
 334         if (!hostname) {
 335                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 336                 return NT_STATUS_INVALID_PARAMETER;
 337         }
 338         if (is_ipaddress(hostname)) {
 339                 DEBUG(2, ("Cannot do GSSAPI to an IP address\n"));
 340                 return NT_STATUS_INVALID_PARAMETER;
 341         }
 342         if (strcmp(hostname, "localhost") == 0) {
 343                 DEBUG(2, ("GSSAPI to 'localhost' does not make sense\n"));
 344                 return NT_STATUS_INVALID_PARAMETER;
 345         }
 346
 347         nt_status = gensec_gssapi_start(gensec_security);
 348         if (!NT_STATUS_IS_OK(nt_status)) {
 349                 return nt_status;
 350         }
 351
 352         gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 353
 354         principal = gensec_get_target_principal(gensec_security);
 355         if (principal && lpcfg_client_use_spnego_principal(gensec_security->settings->lp_ctx)) {
 356                 name_type = GSS_C_NULL_OID;
 357         } else {
 358                 principal = talloc_asprintf(gensec_gssapi_state, "%s/%s@%s",
 359                                             gensec_get_target_service(gensec_security),
 360                                             hostname, lpcfg_realm(gensec_security->settings->lp_ctx));
 361
 362                 name_type = GSS_C_NT_USER_NAME;
 363         }
 364         name_token.value  = discard_const_p(uint8_t, principal);
 365         name_token.length = strlen(principal);
 366
 367
 368         maj_stat = gss_import_name (&min_stat,
 369                                     &name_token,
 370                                     name_type,
 371                                     &gensec_gssapi_state->server_name);
 372         if (maj_stat) {
 373                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 374                           (char *)name_token.value,
 375                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 376                 return NT_STATUS_INVALID_PARAMETER;
 377         }
 378
 379         ret = cli_credentials_get_client_gss_creds(creds,
 380                                                    gensec_security->event_ctx,
 381                                                    gensec_security->settings->lp_ctx, &gcc, &error_string);
 382         switch (ret) {
 383         case 0:
 384                 break;
 385         case KRB5KDC_ERR_PREAUTH_FAILED:
 386                 return NT_STATUS_LOGON_FAILURE;
 387         case KRB5_KDC_UNREACH:
 388                 DEBUG(3, ("Cannot reach a KDC we require to contact %s : %s\n", principal, error_string));
 389                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 390         case KRB5_CC_NOTFOUND:
 391         case KRB5_CC_END:
 392                 DEBUG(3, ("Error preparing credentials we require to contact %s : %s\n", principal, error_string));
 393                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 394         default:
 395                 DEBUG(1, ("Aquiring initiator credentials failed: %s\n", error_string));
 396                 return NT_STATUS_UNSUCCESSFUL;
 397         }
 398
 399         gensec_gssapi_state->client_cred = gcc;
 400         if (!talloc_reference(gensec_gssapi_state, gcc)) {
 401                 return NT_STATUS_NO_MEMORY;
 402         }
 403
 404         return NT_STATUS_OK;
 405 }
 406
 407 static NTSTATUS gensec_gssapi_sasl_client_start(struct gensec_security *gensec_security)
 408 {
 409         NTSTATUS nt_status;
 410         struct gensec_gssapi_state *gensec_gssapi_state;
 411         nt_status = gensec_gssapi_client_start(gensec_security);
 412
 413         if (NT_STATUS_IS_OK(nt_status)) {
 414                 gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 415                 gensec_gssapi_state->sasl = true;
 416         }
 417         return nt_status;
 418 }
 419
 420
 421 /**
 422  * Check if the packet is one for this mechansim
 423  *
 424  * @param gensec_security GENSEC state
 425  * @param in The request, as a DATA_BLOB
 426  * @return Error, INVALID_PARAMETER if it's not a packet for us
 427  *                or NT_STATUS_OK if the packet is ok.
 428  */
 429
 430 static NTSTATUS gensec_gssapi_magic(struct gensec_security *gensec_security,
 431                                     const DATA_BLOB *in)
 432 {
 433         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 434                 return NT_STATUS_OK;
 435         } else {
 436                 return NT_STATUS_INVALID_PARAMETER;
 437         }
 438 }
 439
 440
 441 /**
 442  * Next state function for the GSSAPI GENSEC mechanism
 443  *
 444  * @param gensec_gssapi_state GSSAPI State
 445  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 446  * @param in The request, as a DATA_BLOB
 447  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 448  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 449  *                or NT_STATUS_OK if the user is authenticated.
 450  */
 451
 452 static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 453                                    TALLOC_CTX *out_mem_ctx,
 454                                    const DATA_BLOB in, DATA_BLOB *out)
 455 {
 456         struct gensec_gssapi_state *gensec_gssapi_state
 457                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 458         NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
 459         OM_uint32 maj_stat, min_stat;
 460         OM_uint32 min_stat2;
 461         gss_buffer_desc input_token, output_token;
 462         gss_OID gss_oid_p = NULL;
 463         input_token.length = in.length;
 464         input_token.value = in.data;
 465
 466         switch (gensec_gssapi_state->sasl_state) {
 467         case STAGE_GSS_NEG:
 468         {
 469                 switch (gensec_security->gensec_role) {
 470                 case GENSEC_CLIENT:
 471                 {
 472                         maj_stat = gss_init_sec_context(&min_stat,
 473                                                         gensec_gssapi_state->client_cred->creds,
 474                                                         &gensec_gssapi_state->gssapi_context,
 475                                                         gensec_gssapi_state->server_name,
 476                                                         gensec_gssapi_state->gss_oid,
 477                                                         gensec_gssapi_state->want_flags,
 478                                                         0,
 479                                                         gensec_gssapi_state->input_chan_bindings,
 480                                                         &input_token,
 481                                                         &gss_oid_p,
 482                                                         &output_token,
 483                                                         &gensec_gssapi_state->got_flags, /* ret flags */
 484                                                         NULL);
 485                         if (gss_oid_p) {
 486                                 gensec_gssapi_state->gss_oid = gss_oid_p;
 487                         }
 488                         break;
 489                 }
 490                 case GENSEC_SERVER:
 491                 {
 492                         maj_stat = gss_accept_sec_context(&min_stat,
 493                                                           &gensec_gssapi_state->gssapi_context,
 494                                                           gensec_gssapi_state->server_cred->creds,
 495                                                           &input_token,
 496                                                           gensec_gssapi_state->input_chan_bindings,
 497                                                           &gensec_gssapi_state->client_name,
 498                                                           &gss_oid_p,
 499                                                           &output_token,
 500                                                           &gensec_gssapi_state->got_flags,
 501                                                           NULL,
 502                                                           &gensec_gssapi_state->delegated_cred_handle);
 503                         if (gss_oid_p) {
 504                                 gensec_gssapi_state->gss_oid = gss_oid_p;
 505                         }
 506                         break;
 507                 }
 508                 default:
 509                         return NT_STATUS_INVALID_PARAMETER;
 510
 511                 }
 512
 513                 gensec_gssapi_state->gss_exchange_count++;
 514
 515                 if (maj_stat == GSS_S_COMPLETE) {
 516                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 517                         gss_release_buffer(&min_stat2, &output_token);
 518
 519                         if (gensec_gssapi_state->got_flags & GSS_C_DELEG_FLAG) {
 520                                 DEBUG(5, ("gensec_gssapi: credentials were delegated\n"));
 521                         } else {
 522                                 DEBUG(5, ("gensec_gssapi: NO credentials were delegated\n"));
 523                         }
 524
 525                         /* We may have been invoked as SASL, so there
 526                          * is more work to do */
 527                         if (gensec_gssapi_state->sasl) {
 528                                 /* Due to a very subtle interaction
 529                                  * with SASL and the LDAP libs, we
 530                                  * must ensure the data pointer is
 531                                  * != NULL, but the length is 0.
 532                                  *
 533                                  * This ensures we send a 'zero
 534                                  * length' (rather than NULL) response
 535                                  */
 536
 537                                 if (!out->data) {
 538                                         out->data = (uint8_t *)talloc_strdup(out_mem_ctx, "\0");
 539                                 }
 540
 541                                 gensec_gssapi_state->sasl_state = STAGE_SASL_SSF_NEG;
 542                                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 543                         } else {
 544                                 gensec_gssapi_state->sasl_state = STAGE_DONE;
 545
 546                                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 547                                         DEBUG(5, ("GSSAPI Connection will be cryptographicly sealed\n"));
 548                                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 549                                         DEBUG(5, ("GSSAPI Connection will be cryptographicly signed\n"));
 550                                 } else {
 551                                         DEBUG(5, ("GSSAPI Connection will have no cryptographic protection\n"));
 552                                 }
 553
 554                                 return NT_STATUS_OK;
 555                         }
 556                 } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 557                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 558                         gss_release_buffer(&min_stat2, &output_token);
 559
 560                         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 561                 } else if (gss_oid_equal(gensec_gssapi_state->gss_oid, gss_mech_krb5)) {
 562                         switch (min_stat) {
 563                         case KRB5_KDC_UNREACH:
 564                                 DEBUG(3, ("Cannot reach a KDC we require: %s\n",
 565                                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 566                                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 567                         case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 568                                 DEBUG(3, ("Server is not registered with our KDC: %s\n",
 569                                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 570                                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 571                         case KRB5KRB_AP_ERR_MSG_TYPE:
 572                                 /* garbage input, possibly from the auto-mech detection */
 573                                 return NT_STATUS_INVALID_PARAMETER;
 574                         default:
 575                                 DEBUG(1, ("GSS Update(krb5)(%d) Update failed: %s\n",
 576                                           gensec_gssapi_state->gss_exchange_count,
 577                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 578                                 return nt_status;
 579                         }
 580                 } else {
 581                         DEBUG(1, ("GSS Update(%d) failed: %s\n",
 582                                   gensec_gssapi_state->gss_exchange_count,
 583                                   gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 584                         return nt_status;
 585                 }
 586                 break;
 587         }
 588
 589         /* These last two stages are only done if we were invoked as SASL */
 590         case STAGE_SASL_SSF_NEG:
 591         {
 592                 switch (gensec_security->gensec_role) {
 593                 case GENSEC_CLIENT:
 594                 {
 595                         uint8_t maxlength_proposed[4];
 596                         uint8_t maxlength_accepted[4];
 597                         uint8_t security_supported;
 598                         int conf_state;
 599                         gss_qop_t qop_state;
 600                         input_token.length = in.length;
 601                         input_token.value = in.data;
 602
 603                         /* As a client, we have just send a
 604                          * zero-length blob to the server (after the
 605                          * normal GSSAPI exchange), and it has replied
 606                          * with it's SASL negotiation */
 607
 608                         maj_stat = gss_unwrap(&min_stat,
 609                                               gensec_gssapi_state->gssapi_context,
 610                                               &input_token,
 611                                               &output_token,
 612                                               &conf_state,
 613                                               &qop_state);
 614                         if (GSS_ERROR(maj_stat)) {
 615                                 DEBUG(1, ("gensec_gssapi_update: GSS UnWrap of SASL protection negotiation failed: %s\n",
 616                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 617                                 return NT_STATUS_ACCESS_DENIED;
 618                         }
 619
 620                         if (output_token.length < 4) {
 621                                 return NT_STATUS_INVALID_PARAMETER;
 622                         }
 623
 624                         memcpy(maxlength_proposed, output_token.value, 4);
 625                         gss_release_buffer(&min_stat, &output_token);
 626
 627                         /* first byte is the proposed security */
 628                         security_supported = maxlength_proposed[0];
 629                         maxlength_proposed[0] = '\0';
 630
 631                         /* Rest is the proposed max wrap length */
 632                         gensec_gssapi_state->max_wrap_buf_size = MIN(RIVAL(maxlength_proposed, 0),
 633                                                                      gensec_gssapi_state->max_wrap_buf_size);
 634                         gensec_gssapi_state->sasl_protection = 0;
 635                         if (security_supported & NEG_SEAL) {
 636                                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 637                                         gensec_gssapi_state->sasl_protection |= NEG_SEAL;
 638                                 }
 639                         }
 640                         if (security_supported & NEG_SIGN) {
 641                                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 642                                         gensec_gssapi_state->sasl_protection |= NEG_SIGN;
 643                                 }
 644                         }
 645                         if (security_supported & NEG_NONE) {
 646                                 gensec_gssapi_state->sasl_protection |= NEG_NONE;
 647                         }
 648                         if (gensec_gssapi_state->sasl_protection == 0) {
 649                                 DEBUG(1, ("Remote server does not support unprotected connections\n"));
 650                                 return NT_STATUS_ACCESS_DENIED;
 651                         }
 652
 653                         /* Send back the negotiated max length */
 654
 655                         RSIVAL(maxlength_accepted, 0, gensec_gssapi_state->max_wrap_buf_size);
 656
 657                         maxlength_accepted[0] = gensec_gssapi_state->sasl_protection;
 658
 659                         input_token.value = maxlength_accepted;
 660                         input_token.length = sizeof(maxlength_accepted);
 661
 662                         maj_stat = gss_wrap(&min_stat,
 663                                             gensec_gssapi_state->gssapi_context,
 664                                             false,
 665                                             GSS_C_QOP_DEFAULT,
 666                                             &input_token,
 667                                             &conf_state,
 668                                             &output_token);
 669                         if (GSS_ERROR(maj_stat)) {
 670                                 DEBUG(1, ("GSS Update(SSF_NEG): GSS Wrap failed: %s\n",
 671                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 672                                 return NT_STATUS_ACCESS_DENIED;
 673                         }
 674
 675                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 676                         gss_release_buffer(&min_stat, &output_token);
 677
 678                         /* quirk:  This changes the value that gensec_have_feature returns, to be that after SASL negotiation */
 679                         gensec_gssapi_state->sasl_state = STAGE_DONE;
 680
 681                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 682                                 DEBUG(3, ("SASL/GSSAPI Connection to server will be cryptographicly sealed\n"));
 683                         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 684                                 DEBUG(3, ("SASL/GSSAPI Connection to server will be cryptographicly signed\n"));
 685                         } else {
 686                                 DEBUG(3, ("SASL/GSSAPI Connection to server will have no cryptographicly protection\n"));
 687                         }
 688
 689                         return NT_STATUS_OK;
 690                 }
 691                 case GENSEC_SERVER:
 692                 {
 693                         uint8_t maxlength_proposed[4];
 694                         uint8_t security_supported = 0x0;
 695                         int conf_state;
 696
 697                         /* As a server, we have just been sent a zero-length blob (note this, but it isn't fatal) */
 698                         if (in.length != 0) {
 699                                 DEBUG(1, ("SASL/GSSAPI: client sent non-zero length starting SASL negotiation!\n"));
 700                         }
 701
 702                         /* Give the client some idea what we will support */
 703
 704                         RSIVAL(maxlength_proposed, 0, gensec_gssapi_state->max_wrap_buf_size);
 705                         /* first byte is the proposed security */
 706                         maxlength_proposed[0] = '\0';
 707
 708                         gensec_gssapi_state->sasl_protection = 0;
 709                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 710                                 security_supported |= NEG_SEAL;
 711                         }
 712                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 713                                 security_supported |= NEG_SIGN;
 714                         }
 715                         if (security_supported == 0) {
 716                                 /* If we don't support anything, this must be 0 */
 717                                 RSIVAL(maxlength_proposed, 0, 0x0);
 718                         }
 719
 720                         /* TODO:  We may not wish to support this */
 721                         security_supported |= NEG_NONE;
 722                         maxlength_proposed[0] = security_supported;
 723
 724                         input_token.value = maxlength_proposed;
 725                         input_token.length = sizeof(maxlength_proposed);
 726
 727                         maj_stat = gss_wrap(&min_stat,
 728                                             gensec_gssapi_state->gssapi_context,
 729                                             false,
 730                                             GSS_C_QOP_DEFAULT,
 731                                             &input_token,
 732                                             &conf_state,
 733                                             &output_token);
 734                         if (GSS_ERROR(maj_stat)) {
 735                                 DEBUG(1, ("GSS Update(SSF_NEG): GSS Wrap failed: %s\n",
 736                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 737                                 return NT_STATUS_ACCESS_DENIED;
 738                         }
 739
 740                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 741                         gss_release_buffer(&min_stat, &output_token);
 742
 743                         gensec_gssapi_state->sasl_state = STAGE_SASL_SSF_ACCEPT;
 744                         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 745                 }
 746                 default:
 747                         return NT_STATUS_INVALID_PARAMETER;
 748
 749                 }
 750         }
 751         /* This is s server-only stage */
 752         case STAGE_SASL_SSF_ACCEPT:
 753         {
 754                 uint8_t maxlength_accepted[4];
 755                 uint8_t security_accepted;
 756                 int conf_state;
 757                 gss_qop_t qop_state;
 758                 input_token.length = in.length;
 759                 input_token.value = in.data;
 760
 761                 maj_stat = gss_unwrap(&min_stat,
 762                                       gensec_gssapi_state->gssapi_context,
 763                                       &input_token,
 764                                       &output_token,
 765                                       &conf_state,
 766                                       &qop_state);
 767                 if (GSS_ERROR(maj_stat)) {
 768                         DEBUG(1, ("gensec_gssapi_update: GSS UnWrap of SASL protection negotiation failed: %s\n",
 769                                   gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 770                         return NT_STATUS_ACCESS_DENIED;
 771                 }
 772
 773                 if (output_token.length < 4) {
 774                         return NT_STATUS_INVALID_PARAMETER;
 775                 }
 776
 777                 memcpy(maxlength_accepted, output_token.value, 4);
 778                 gss_release_buffer(&min_stat, &output_token);
 779
 780                 /* first byte is the proposed security */
 781                 security_accepted = maxlength_accepted[0];
 782                 maxlength_accepted[0] = '\0';
 783
 784                 /* Rest is the proposed max wrap length */
 785                 gensec_gssapi_state->max_wrap_buf_size = MIN(RIVAL(maxlength_accepted, 0),
 786                                                              gensec_gssapi_state->max_wrap_buf_size);
 787
 788                 gensec_gssapi_state->sasl_protection = 0;
 789                 if (security_accepted & NEG_SEAL) {
 790                         if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 791                                 DEBUG(1, ("Remote client wanted seal, but gensec refused\n"));
 792                                 return NT_STATUS_ACCESS_DENIED;
 793                         }
 794                         gensec_gssapi_state->sasl_protection |= NEG_SEAL;
 795                 }
 796                 if (security_accepted & NEG_SIGN) {
 797                         if (!gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 798                                 DEBUG(1, ("Remote client wanted sign, but gensec refused\n"));
 799                                 return NT_STATUS_ACCESS_DENIED;
 800                         }
 801                         gensec_gssapi_state->sasl_protection |= NEG_SIGN;
 802                 }
 803                 if (security_accepted & NEG_NONE) {
 804                         gensec_gssapi_state->sasl_protection |= NEG_NONE;
 805                 }
 806
 807                 /* quirk:  This changes the value that gensec_have_feature returns, to be that after SASL negotiation */
 808                 gensec_gssapi_state->sasl_state = STAGE_DONE;
 809                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 810                         DEBUG(5, ("SASL/GSSAPI Connection from client will be cryptographicly sealed\n"));
 811                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 812                         DEBUG(5, ("SASL/GSSAPI Connection from client will be cryptographicly signed\n"));
 813                 } else {
 814                         DEBUG(5, ("SASL/GSSAPI Connection from client will have no cryptographic protection\n"));
 815                 }
 816
 817                 *out = data_blob(NULL, 0);
 818                 return NT_STATUS_OK;
 819         }
 820         default:
 821                 return NT_STATUS_INVALID_PARAMETER;
 822         }
 823 }
 824
 825 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 826                                    TALLOC_CTX *mem_ctx,
 827                                    const DATA_BLOB *in,
 828                                    DATA_BLOB *out)
 829 {
 830         struct gensec_gssapi_state *gensec_gssapi_state
 831                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 832         OM_uint32 maj_stat, min_stat;
 833         gss_buffer_desc input_token, output_token;
 834         int conf_state;
 835         input_token.length = in->length;
 836         input_token.value = in->data;
 837
 838         maj_stat = gss_wrap(&min_stat,
 839                             gensec_gssapi_state->gssapi_context,
 840                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 841                             GSS_C_QOP_DEFAULT,
 842                             &input_token,
 843                             &conf_state,
 844                             &output_token);
 845         if (GSS_ERROR(maj_stat)) {
 846                 DEBUG(1, ("gensec_gssapi_wrap: GSS Wrap failed: %s\n",
 847                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 848                 return NT_STATUS_ACCESS_DENIED;
 849         }
 850
 851         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 852         gss_release_buffer(&min_stat, &output_token);
 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 < out->length) {
 857                         DEBUG(1, ("gensec_gssapi_wrap: when wrapped, INPUT data (%u) is grew to be larger than SASL negotiated maximum output size (%u > %u)\n",
 858                                   (unsigned)in->length,
 859                                   (unsigned)out->length,
 860                                   (unsigned int)max_wrapped_size));
 861                         return NT_STATUS_INVALID_PARAMETER;
 862                 }
 863         }
 864
 865         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 866             && !conf_state) {
 867                 return NT_STATUS_ACCESS_DENIED;
 868         }
 869         return NT_STATUS_OK;
 870 }
 871
 872 static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 873                                      TALLOC_CTX *mem_ctx,
 874                                      const DATA_BLOB *in,
 875                                      DATA_BLOB *out)
 876 {
 877         struct gensec_gssapi_state *gensec_gssapi_state
 878                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 879         OM_uint32 maj_stat, min_stat;
 880         gss_buffer_desc input_token, output_token;
 881         int conf_state;
 882         gss_qop_t qop_state;
 883         input_token.length = in->length;
 884         input_token.value = in->data;
 885
 886         if (gensec_gssapi_state->sasl) {
 887                 size_t max_wrapped_size = gensec_gssapi_max_wrapped_size(gensec_security);
 888                 if (max_wrapped_size < in->length) {
 889                         DEBUG(1, ("gensec_gssapi_unwrap: WRAPPED data is larger than SASL negotiated maximum size\n"));
 890                         return NT_STATUS_INVALID_PARAMETER;
 891                 }
 892         }
 893
 894         maj_stat = gss_unwrap(&min_stat,
 895                               gensec_gssapi_state->gssapi_context,
 896                               &input_token,
 897                               &output_token,
 898                               &conf_state,
 899                               &qop_state);
 900         if (GSS_ERROR(maj_stat)) {
 901                 DEBUG(1, ("gensec_gssapi_unwrap: GSS UnWrap failed: %s\n",
 902                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 903                 return NT_STATUS_ACCESS_DENIED;
 904         }
 905
 906         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 907         gss_release_buffer(&min_stat, &output_token);
 908
 909         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 910             && !conf_state) {
 911                 return NT_STATUS_ACCESS_DENIED;
 912         }
 913         return NT_STATUS_OK;
 914 }
 915
 916 /* Find out the maximum input size negotiated on this connection */
 917
 918 static size_t gensec_gssapi_max_input_size(struct gensec_security *gensec_security)
 919 {
 920         struct gensec_gssapi_state *gensec_gssapi_state
 921                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 922         OM_uint32 maj_stat, min_stat;
 923         OM_uint32 max_input_size;
 924
 925         maj_stat = gss_wrap_size_limit(&min_stat,
 926                                        gensec_gssapi_state->gssapi_context,
 927                                        gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 928                                        GSS_C_QOP_DEFAULT,
 929                                        gensec_gssapi_state->max_wrap_buf_size,
 930                                        &max_input_size);
 931         if (GSS_ERROR(maj_stat)) {
 932                 TALLOC_CTX *mem_ctx = talloc_new(NULL);
 933                 DEBUG(1, ("gensec_gssapi_max_input_size: determinaing signature size with gss_wrap_size_limit failed: %s\n",
 934                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 935                 talloc_free(mem_ctx);
 936                 return 0;
 937         }
 938
 939         return max_input_size;
 940 }
 941
 942 /* Find out the maximum output size negotiated on this connection */
 943 static size_t gensec_gssapi_max_wrapped_size(struct gensec_security *gensec_security)
 944 {
 945         struct gensec_gssapi_state *gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);;
 946         return gensec_gssapi_state->max_wrap_buf_size;
 947 }
 948
 949 static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_security,
 950                                           TALLOC_CTX *mem_ctx,
 951                                           uint8_t *data, size_t length,
 952                                           const uint8_t *whole_pdu, size_t pdu_length,
 953                                           DATA_BLOB *sig)
 954 {
 955         struct gensec_gssapi_state *gensec_gssapi_state
 956                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 957         OM_uint32 maj_stat, min_stat;
 958         gss_buffer_desc input_token, output_token;
 959         int conf_state;
 960         ssize_t sig_length;
 961
 962         input_token.length = length;
 963         input_token.value = data;
 964
 965         maj_stat = gss_wrap(&min_stat,
 966                             gensec_gssapi_state->gssapi_context,
 967                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 968                             GSS_C_QOP_DEFAULT,
 969                             &input_token,
 970                             &conf_state,
 971                             &output_token);
 972         if (GSS_ERROR(maj_stat)) {
 973                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap failed: %s\n",
 974                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 975                 return NT_STATUS_ACCESS_DENIED;
 976         }
 977
 978         if (output_token.length < input_token.length) {
 979                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap length [%ld] *less* than caller length [%ld]\n",
 980                           (long)output_token.length, (long)length));
 981                 return NT_STATUS_INTERNAL_ERROR;
 982         }
 983         sig_length = output_token.length - input_token.length;
 984
 985         memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);
 986         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 987
 988         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 989         dump_data_pw("gensec_gssapi_seal_packet: clear\n", data, length);
 990         dump_data_pw("gensec_gssapi_seal_packet: sealed\n", ((uint8_t *)output_token.value) + sig_length, output_token.length - sig_length);
 991
 992         gss_release_buffer(&min_stat, &output_token);
 993
 994         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 995             && !conf_state) {
 996                 return NT_STATUS_ACCESS_DENIED;
 997         }
 998         return NT_STATUS_OK;
 999 }
1000
1001 static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_security,
1002                                             TALLOC_CTX *mem_ctx,
1003                                             uint8_t *data, size_t length,
1004                                             const uint8_t *whole_pdu, size_t pdu_length,
1005                                             const DATA_BLOB *sig)
1006 {
1007         struct gensec_gssapi_state *gensec_gssapi_state
1008                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1009         OM_uint32 maj_stat, min_stat;
1010         gss_buffer_desc input_token, output_token;
1011         int conf_state;
1012         gss_qop_t qop_state;
1013         DATA_BLOB in;
1014
1015         dump_data_pw("gensec_gssapi_unseal_packet: sig\n", sig->data, sig->length);
1016
1017         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
1018
1019         memcpy(in.data, sig->data, sig->length);
1020         memcpy(in.data + sig->length, data, length);
1021
1022         input_token.length = in.length;
1023         input_token.value = in.data;
1024
1025         maj_stat = gss_unwrap(&min_stat,
1026                               gensec_gssapi_state->gssapi_context,
1027                               &input_token,
1028                               &output_token,
1029                               &conf_state,
1030                               &qop_state);
1031         if (GSS_ERROR(maj_stat)) {
1032                 DEBUG(1, ("gensec_gssapi_unseal_packet: GSS UnWrap failed: %s\n",
1033                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1034                 return NT_STATUS_ACCESS_DENIED;
1035         }
1036
1037         if (output_token.length != length) {
1038                 return NT_STATUS_INTERNAL_ERROR;
1039         }
1040
1041         memcpy(data, output_token.value, length);
1042
1043         gss_release_buffer(&min_stat, &output_token);
1044
1045         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
1046             && !conf_state) {
1047                 return NT_STATUS_ACCESS_DENIED;
1048         }
1049         return NT_STATUS_OK;
1050 }
1051
1052 static NTSTATUS gensec_gssapi_sign_packet(struct gensec_security *gensec_security,
1053                                           TALLOC_CTX *mem_ctx,
1054                                           const uint8_t *data, size_t length,
1055                                           const uint8_t *whole_pdu, size_t pdu_length,
1056                                           DATA_BLOB *sig)
1057 {
1058         struct gensec_gssapi_state *gensec_gssapi_state
1059                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1060         OM_uint32 maj_stat, min_stat;
1061         gss_buffer_desc input_token, output_token;
1062
1063         if (gensec_security->want_features & GENSEC_FEATURE_SIGN_PKT_HEADER) {
1064                 input_token.length = pdu_length;
1065                 input_token.value = discard_const_p(uint8_t *, whole_pdu);
1066         } else {
1067                 input_token.length = length;
1068                 input_token.value = discard_const_p(uint8_t *, data);
1069         }
1070
1071         maj_stat = gss_get_mic(&min_stat,
1072                             gensec_gssapi_state->gssapi_context,
1073                             GSS_C_QOP_DEFAULT,
1074                             &input_token,
1075                             &output_token);
1076         if (GSS_ERROR(maj_stat)) {
1077                 DEBUG(1, ("GSS GetMic failed: %s\n",
1078                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1079                 return NT_STATUS_ACCESS_DENIED;
1080         }
1081
1082         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, output_token.length);
1083
1084         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
1085
1086         gss_release_buffer(&min_stat, &output_token);
1087
1088         return NT_STATUS_OK;
1089 }
1090
1091 static NTSTATUS gensec_gssapi_check_packet(struct gensec_security *gensec_security,
1092                                            TALLOC_CTX *mem_ctx,
1093                                            const uint8_t *data, size_t length,
1094                                            const uint8_t *whole_pdu, size_t pdu_length,
1095                                            const DATA_BLOB *sig)
1096 {
1097         struct gensec_gssapi_state *gensec_gssapi_state
1098                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1099         OM_uint32 maj_stat, min_stat;
1100         gss_buffer_desc input_token;
1101         gss_buffer_desc input_message;
1102         gss_qop_t qop_state;
1103
1104         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
1105
1106         if (gensec_security->want_features & GENSEC_FEATURE_SIGN_PKT_HEADER) {
1107                 input_message.length = pdu_length;
1108                 input_message.value = discard_const(whole_pdu);
1109         } else {
1110                 input_message.length = length;
1111                 input_message.value = discard_const(data);
1112         }
1113
1114         input_token.length = sig->length;
1115         input_token.value = sig->data;
1116
1117         maj_stat = gss_verify_mic(&min_stat,
1118                               gensec_gssapi_state->gssapi_context,
1119                               &input_message,
1120                               &input_token,
1121                               &qop_state);
1122         if (GSS_ERROR(maj_stat)) {
1123                 DEBUG(1, ("GSS VerifyMic failed: %s\n",
1124                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1125                 return NT_STATUS_ACCESS_DENIED;
1126         }
1127
1128         return NT_STATUS_OK;
1129 }
1130
1131 /* Try to figure out what features we actually got on the connection */
1132 static bool gensec_gssapi_have_feature(struct gensec_security *gensec_security,
1133                                        uint32_t feature)
1134 {
1135         struct gensec_gssapi_state *gensec_gssapi_state
1136                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1137         if (feature & GENSEC_FEATURE_SIGN) {
1138                 /* If we are going GSSAPI SASL, then we honour the second negotiation */
1139                 if (gensec_gssapi_state->sasl
1140                     && gensec_gssapi_state->sasl_state == STAGE_DONE) {
1141                         return ((gensec_gssapi_state->sasl_protection & NEG_SIGN)
1142                                 && (gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG));
1143                 }
1144                 return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
1145         }
1146         if (feature & GENSEC_FEATURE_SEAL) {
1147                 /* If we are going GSSAPI SASL, then we honour the second negotiation */
1148                 if (gensec_gssapi_state->sasl
1149                     && gensec_gssapi_state->sasl_state == STAGE_DONE) {
1150                         return ((gensec_gssapi_state->sasl_protection & NEG_SEAL)
1151                                  && (gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG));
1152                 }
1153                 return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
1154         }
1155         if (feature & GENSEC_FEATURE_SESSION_KEY) {
1156                 /* Only for GSSAPI/Krb5 */
1157                 if (gss_oid_equal(gensec_gssapi_state->gss_oid, gss_mech_krb5)) {
1158                         return true;
1159                 }
1160         }
1161         if (feature & GENSEC_FEATURE_DCE_STYLE) {
1162                 return gensec_gssapi_state->got_flags & GSS_C_DCE_STYLE;
1163         }
1164         if (feature & GENSEC_FEATURE_NEW_SPNEGO) {
1165                 NTSTATUS status;
1166
1167                 if (!(gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG)) {
1168                         return false;
1169                 }
1170
1171                 if (gensec_setting_bool(gensec_security->settings, "gensec_gssapi", "force_new_spnego", false)) {
1172                         return true;
1173                 }
1174                 if (gensec_setting_bool(gensec_security->settings, "gensec_gssapi", "disable_new_spnego", false)) {
1175                         return false;
1176                 }
1177
1178                 status = gensec_gssapi_init_lucid(gensec_gssapi_state);
1179                 if (!NT_STATUS_IS_OK(status)) {
1180                         return false;
1181                 }
1182
1183                 if (gensec_gssapi_state->lucid->protocol == 1) {
1184                         return true;
1185                 }
1186
1187                 return false;
1188         }
1189         /* We can always do async (rather than strict request/reply) packets.  */
1190         if (feature & GENSEC_FEATURE_ASYNC_REPLIES) {
1191                 return true;
1192         }
1193         return false;
1194 }
1195
1196 /*
1197  * Extract the 'sesssion key' needed by SMB signing and ncacn_np
1198  * (for encrypting some passwords).
1199  *
1200  * This breaks all the abstractions, but what do you expect...
1201  */
1202 static NTSTATUS gensec_gssapi_session_key(struct gensec_security *gensec_security,
1203                                           DATA_BLOB *session_key)
1204 {
1205         struct gensec_gssapi_state *gensec_gssapi_state
1206                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1207         OM_uint32 maj_stat, min_stat;
1208         krb5_keyblock *subkey;
1209
1210         if (gensec_gssapi_state->sasl_state != STAGE_DONE) {
1211                 return NT_STATUS_NO_USER_SESSION_KEY;
1212         }
1213
1214         if (gensec_gssapi_state->session_key.data) {
1215                 *session_key = gensec_gssapi_state->session_key;
1216                 return NT_STATUS_OK;
1217         }
1218
1219         maj_stat = gsskrb5_get_subkey(&min_stat,
1220                                       gensec_gssapi_state->gssapi_context,
1221                                       &subkey);
1222         if (maj_stat != 0) {
1223                 DEBUG(1, ("NO session key for this mech\n"));
1224                 return NT_STATUS_NO_USER_SESSION_KEY;
1225         }
1226
1227         DEBUG(10, ("Got KRB5 session key of length %d%s\n",
1228                    (int)KRB5_KEY_LENGTH(subkey),
1229                    (gensec_gssapi_state->sasl_state == STAGE_DONE)?" (done)":""));
1230         *session_key = data_blob_talloc(gensec_gssapi_state,
1231                                         KRB5_KEY_DATA(subkey), KRB5_KEY_LENGTH(subkey));
1232         krb5_free_keyblock(gensec_gssapi_state->smb_krb5_context->krb5_context, subkey);
1233         gensec_gssapi_state->session_key = *session_key;
1234         dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
1235
1236         return NT_STATUS_OK;
1237 }
1238
1239 /* Get some basic (and authorization) information about the user on
1240  * this session.  This uses either the PAC (if present) or a local
1241  * database lookup */
1242 static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_security,
1243                                            struct auth_session_info **_session_info)
1244 {
1245         NTSTATUS nt_status;
1246         TALLOC_CTX *mem_ctx;
1247         struct gensec_gssapi_state *gensec_gssapi_state
1248                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1249         struct auth_serversupplied_info *server_info = NULL;
1250         struct auth_session_info *session_info = NULL;
1251         OM_uint32 maj_stat, min_stat;
1252         gss_buffer_desc pac;
1253         DATA_BLOB pac_blob;
1254
1255         if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
1256             || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
1257                        gensec_gssapi_state->gss_oid->length) != 0)) {
1258                 DEBUG(1, ("NO session info available for this mech\n"));
1259                 return NT_STATUS_INVALID_PARAMETER;
1260         }
1261
1262         mem_ctx = talloc_named(gensec_gssapi_state, 0, "gensec_gssapi_session_info context");
1263         NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
1264
1265         maj_stat = gsskrb5_extract_authz_data_from_sec_context(&min_stat,
1266                                                                gensec_gssapi_state->gssapi_context,
1267                                                                KRB5_AUTHDATA_WIN2K_PAC,
1268                                                                &pac);
1269
1270
1271         if (maj_stat == 0) {
1272                 pac_blob = data_blob_talloc(mem_ctx, pac.value, pac.length);
1273                 gss_release_buffer(&min_stat, &pac);
1274
1275         } else {
1276                 pac_blob = data_blob(NULL, 0);
1277         }
1278
1279         /* IF we have the PAC - otherwise we need to get this
1280          * data from elsewere - local ldb, or (TODO) lookup of some
1281          * kind...
1282          */
1283         if (pac_blob.length) {
1284                 nt_status = kerberos_pac_blob_to_server_info(mem_ctx,
1285                                                              pac_blob,
1286                                                              gensec_gssapi_state->smb_krb5_context->krb5_context,
1287                                                              &server_info);
1288                 if (!NT_STATUS_IS_OK(nt_status)) {
1289                         talloc_free(mem_ctx);
1290                         return nt_status;
1291                 }
1292         } else {
1293                 gss_buffer_desc name_token;
1294                 char *principal_string;
1295
1296                 maj_stat = gss_display_name (&min_stat,
1297                                              gensec_gssapi_state->client_name,
1298                                              &name_token,
1299                                              NULL);
1300                 if (GSS_ERROR(maj_stat)) {
1301                         DEBUG(1, ("GSS display_name failed: %s\n",
1302                                   gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1303                         talloc_free(mem_ctx);
1304                         return NT_STATUS_FOOBAR;
1305                 }
1306
1307                 principal_string = talloc_strndup(mem_ctx,
1308                                                   (const char *)name_token.value,
1309                                                   name_token.length);
1310
1311                 gss_release_buffer(&min_stat, &name_token);
1312
1313                 if (!principal_string) {
1314                         talloc_free(mem_ctx);
1315                         return NT_STATUS_NO_MEMORY;
1316                 }
1317
1318                 if (gensec_security->auth_context &&
1319                     !gensec_setting_bool(gensec_security->settings, "gensec", "require_pac", false)) {
1320                         DEBUG(1, ("Unable to find PAC, resorting to local user lookup: %s\n",
1321                                   gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1322                         nt_status = gensec_security->auth_context->get_server_info_principal(mem_ctx,
1323                                                                                              gensec_security->auth_context,
1324                                                                                              principal_string,
1325                                                                                              NULL,
1326                                                                                              &server_info);
1327
1328                         if (!NT_STATUS_IS_OK(nt_status)) {
1329                                 talloc_free(mem_ctx);
1330                                 return nt_status;
1331                         }
1332                 } else {
1333                         DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access: %s\n",
1334                                   principal_string,
1335                                   gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1336                         return NT_STATUS_ACCESS_DENIED;
1337                 }
1338         }
1339
1340         /* references the server_info into the session_info */
1341         nt_status = gensec_generate_session_info(mem_ctx, gensec_security,
1342                                                  server_info, &session_info);
1343         if (!NT_STATUS_IS_OK(nt_status)) {
1344                 talloc_free(mem_ctx);
1345                 return nt_status;
1346         }
1347
1348         nt_status = gensec_gssapi_session_key(gensec_security, &session_info->session_key);
1349         if (!NT_STATUS_IS_OK(nt_status)) {
1350                 talloc_free(mem_ctx);
1351                 return nt_status;
1352         }
1353
1354         if (!(gensec_gssapi_state->got_flags & GSS_C_DELEG_FLAG)) {
1355                 DEBUG(10, ("gensec_gssapi: NO delegated credentials supplied by client\n"));
1356         } else {
1357                 krb5_error_code ret;
1358                 const char *error_string;
1359
1360                 DEBUG(10, ("gensec_gssapi: delegated credentials supplied by client\n"));
1361                 session_info->credentials = cli_credentials_init(session_info);
1362                 if (!session_info->credentials) {
1363                         talloc_free(mem_ctx);
1364                         return NT_STATUS_NO_MEMORY;
1365                 }
1366
1367                 cli_credentials_set_conf(session_info->credentials, gensec_security->settings->lp_ctx);
1368                 /* Just so we don't segfault trying to get at a username */
1369                 cli_credentials_set_anonymous(session_info->credentials);
1370
1371                 ret = cli_credentials_set_client_gss_creds(session_info->credentials,
1372                                                            gensec_security->event_ctx,
1373                                                            gensec_security->settings->lp_ctx,
1374                                                            gensec_gssapi_state->delegated_cred_handle,
1375                                                            CRED_SPECIFIED, &error_string);
1376                 if (ret) {
1377                         talloc_free(mem_ctx);
1378                         DEBUG(2,("Failed to get gss creds: %s\n", error_string));
1379                         return NT_STATUS_NO_MEMORY;
1380                 }
1381
1382                 /* This credential handle isn't useful for password authentication, so ensure nobody tries to do that */
1383                 cli_credentials_set_kerberos_state(session_info->credentials, CRED_MUST_USE_KERBEROS);
1384
1385                 /* It has been taken from this place... */
1386                 gensec_gssapi_state->delegated_cred_handle = GSS_C_NO_CREDENTIAL;
1387         }
1388         talloc_steal(gensec_gssapi_state, session_info);
1389         talloc_free(mem_ctx);
1390         *_session_info = session_info;
1391
1392         return NT_STATUS_OK;
1393 }
1394
1395 static size_t gensec_gssapi_sig_size(struct gensec_security *gensec_security, size_t data_size)
1396 {
1397         struct gensec_gssapi_state *gensec_gssapi_state
1398                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1399         NTSTATUS status;
1400
1401         if (gensec_gssapi_state->sig_size) {
1402                 return gensec_gssapi_state->sig_size;
1403         }
1404
1405         if (gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG) {
1406                 gensec_gssapi_state->sig_size = 45;
1407         } else {
1408                 gensec_gssapi_state->sig_size = 37;
1409         }
1410
1411         status = gensec_gssapi_init_lucid(gensec_gssapi_state);
1412         if (!NT_STATUS_IS_OK(status)) {
1413                 return gensec_gssapi_state->sig_size;
1414         }
1415
1416         if (gensec_gssapi_state->lucid->protocol == 1) {
1417                 if (gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG) {
1418                         /*
1419                          * TODO: windows uses 76 here, but we don't know
1420                          *       gss_wrap works with aes keys yet
1421                          */
1422                         gensec_gssapi_state->sig_size = 76;
1423                 } else {
1424                         gensec_gssapi_state->sig_size = 28;
1425                 }
1426         } else if (gensec_gssapi_state->lucid->protocol == 0) {
1427                 switch (gensec_gssapi_state->lucid->rfc1964_kd.ctx_key.type) {
1428                 case KEYTYPE_DES:
1429                 case KEYTYPE_ARCFOUR:
1430                 case KEYTYPE_ARCFOUR_56:
1431                         if (gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG) {
1432                                 gensec_gssapi_state->sig_size = 45;
1433                         } else {
1434                                 gensec_gssapi_state->sig_size = 37;
1435                         }
1436                         break;
1437                 case KEYTYPE_DES3:
1438                         if (gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG) {
1439                                 gensec_gssapi_state->sig_size = 57;
1440                         } else {
1441                                 gensec_gssapi_state->sig_size = 49;
1442                         }
1443                         break;
1444                 }
1445         }
1446
1447         return gensec_gssapi_state->sig_size;
1448 }
1449
1450 static const char *gensec_gssapi_krb5_oids[] = {
1451         GENSEC_OID_KERBEROS5_OLD,
1452         GENSEC_OID_KERBEROS5,
1453         NULL
1454 };
1455
1456 static const char *gensec_gssapi_spnego_oids[] = {
1457         GENSEC_OID_SPNEGO,
1458         NULL
1459 };
1460
1461 /* As a server, this could in theory accept any GSSAPI mech */
1462 static const struct gensec_security_ops gensec_gssapi_spnego_security_ops = {
1463         .name           = "gssapi_spnego",
1464         .sasl_name      = "GSS-SPNEGO",
1465         .auth_type      = DCERPC_AUTH_TYPE_SPNEGO,
1466         .oid            = gensec_gssapi_spnego_oids,
1467         .client_start   = gensec_gssapi_client_start,
1468         .server_start   = gensec_gssapi_server_start,
1469         .magic          = gensec_gssapi_magic,
1470         .update         = gensec_gssapi_update,
1471         .session_key    = gensec_gssapi_session_key,
1472         .session_info   = gensec_gssapi_session_info,
1473         .sign_packet    = gensec_gssapi_sign_packet,
1474         .check_packet   = gensec_gssapi_check_packet,
1475         .seal_packet    = gensec_gssapi_seal_packet,
1476         .unseal_packet  = gensec_gssapi_unseal_packet,
1477         .wrap           = gensec_gssapi_wrap,
1478         .unwrap         = gensec_gssapi_unwrap,
1479         .have_feature   = gensec_gssapi_have_feature,
1480         .enabled        = false,
1481         .kerberos       = true,
1482         .priority       = GENSEC_GSSAPI
1483 };
1484
1485 /* As a server, this could in theory accept any GSSAPI mech */
1486 static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
1487         .name           = "gssapi_krb5",
1488         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
1489         .oid            = gensec_gssapi_krb5_oids,
1490         .client_start   = gensec_gssapi_client_start,
1491         .server_start   = gensec_gssapi_server_start,
1492         .magic          = gensec_gssapi_magic,
1493         .update         = gensec_gssapi_update,
1494         .session_key    = gensec_gssapi_session_key,
1495         .session_info   = gensec_gssapi_session_info,
1496         .sig_size       = gensec_gssapi_sig_size,
1497         .sign_packet    = gensec_gssapi_sign_packet,
1498         .check_packet   = gensec_gssapi_check_packet,
1499         .seal_packet    = gensec_gssapi_seal_packet,
1500         .unseal_packet  = gensec_gssapi_unseal_packet,
1501         .wrap           = gensec_gssapi_wrap,
1502         .unwrap         = gensec_gssapi_unwrap,
1503         .have_feature   = gensec_gssapi_have_feature,
1504         .enabled        = true,
1505         .kerberos       = true,
1506         .priority       = GENSEC_GSSAPI
1507 };
1508
1509 /* As a server, this could in theory accept any GSSAPI mech */
1510 static const struct gensec_security_ops gensec_gssapi_sasl_krb5_security_ops = {
1511         .name             = "gssapi_krb5_sasl",
1512         .sasl_name        = "GSSAPI",
1513         .client_start     = gensec_gssapi_sasl_client_start,
1514         .server_start     = gensec_gssapi_sasl_server_start,
1515         .update           = gensec_gssapi_update,
1516         .session_key      = gensec_gssapi_session_key,
1517         .session_info     = gensec_gssapi_session_info,
1518         .max_input_size   = gensec_gssapi_max_input_size,
1519         .max_wrapped_size = gensec_gssapi_max_wrapped_size,
1520         .wrap             = gensec_gssapi_wrap,
1521         .unwrap           = gensec_gssapi_unwrap,
1522         .have_feature     = gensec_gssapi_have_feature,
1523         .enabled          = true,
1524         .kerberos         = true,
1525         .priority         = GENSEC_GSSAPI
1526 };
1527
1528 _PUBLIC_ NTSTATUS gensec_gssapi_init(void)
1529 {
1530         NTSTATUS ret;
1531
1532         ret = gensec_register(&gensec_gssapi_spnego_security_ops);
1533         if (!NT_STATUS_IS_OK(ret)) {
1534                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1535                         gensec_gssapi_spnego_security_ops.name));
1536                 return ret;
1537         }
1538
1539         ret = gensec_register(&gensec_gssapi_krb5_security_ops);
1540         if (!NT_STATUS_IS_OK(ret)) {
1541                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1542                         gensec_gssapi_krb5_security_ops.name));
1543                 return ret;
1544         }
1545
1546         ret = gensec_register(&gensec_gssapi_sasl_krb5_security_ops);
1547         if (!NT_STATUS_IS_OK(ret)) {
1548                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1549                         gensec_gssapi_sasl_krb5_security_ops.name));
1550                 return ret;
1551         }
1552
1553         return ret;
1554 }