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 "heimdal/lib/gssapi/gssapi/gssapi.h"
  28 #include "auth/kerberos/kerberos.h"
  29 #include "librpc/gen_ndr/krb5pac.h"
  30 #include "auth/auth.h"
  31 #include "lib/ldb/include/ldb.h"
  32 #include "auth/auth_sam.h"
  33 #include "librpc/rpc/dcerpc.h"
  34 #include "auth/credentials/credentials.h"
  35 #include "auth/credentials/credentials_krb5.h"
  36 #include "auth/gensec/gensec.h"
  37 #include "auth/gensec/gensec_proto.h"
  38 #include "param/param.h"
  39 #include "auth/session_proto.h"
  40
  41 enum gensec_gssapi_sasl_state
  42 {
  43         STAGE_GSS_NEG,
  44         STAGE_SASL_SSF_NEG,
  45         STAGE_SASL_SSF_ACCEPT,
  46         STAGE_DONE
  47 };
  48
  49 #define NEG_SEAL 0x4
  50 #define NEG_SIGN 0x2
  51 #define NEG_NONE 0x1
  52
  53 struct gensec_gssapi_state {
  54         gss_ctx_id_t gssapi_context;
  55         struct gss_channel_bindings_struct *input_chan_bindings;
  56         gss_name_t server_name;
  57         gss_name_t client_name;
  58         OM_uint32 want_flags, got_flags;
  59         gss_OID gss_oid;
  60
  61         DATA_BLOB session_key;
  62         DATA_BLOB pac;
  63
  64         struct smb_krb5_context *smb_krb5_context;
  65         struct gssapi_creds_container *client_cred;
  66         struct gssapi_creds_container *server_cred;
  67
  68         gss_cred_id_t delegated_cred_handle;
  69
  70         bool sasl; /* We have two different mechs in this file: One
  71                     * for SASL wrapped GSSAPI and another for normal
  72                     * GSSAPI */
  73         enum gensec_gssapi_sasl_state sasl_state;
  74         uint8_t sasl_protection; /* What was negotiated at the SASL
  75                                   * layer, independent of the GSSAPI
  76                                   * layer... */
  77
  78         size_t max_wrap_buf_size;
  79         int gss_exchange_count;
  80 };
  81
  82 static size_t gensec_gssapi_max_input_size(struct gensec_security *gensec_security);
  83 static size_t gensec_gssapi_max_wrapped_size(struct gensec_security *gensec_security);
  84
  85 static char *gssapi_error_string(TALLOC_CTX *mem_ctx,
  86                                  OM_uint32 maj_stat, OM_uint32 min_stat,
  87                                  const gss_OID mech)
  88 {
  89         OM_uint32 disp_min_stat, disp_maj_stat;
  90         gss_buffer_desc maj_error_message;
  91         gss_buffer_desc min_error_message;
  92         char *maj_error_string, *min_error_string;
  93         OM_uint32 msg_ctx = 0;
  94
  95         char *ret;
  96
  97         maj_error_message.value = NULL;
  98         min_error_message.value = NULL;
  99         maj_error_message.length = 0;
 100         min_error_message.length = 0;
 101
 102         disp_maj_stat = gss_display_status(&disp_min_stat, maj_stat, GSS_C_GSS_CODE,
 103                            mech, &msg_ctx, &maj_error_message);
 104         disp_maj_stat = gss_display_status(&disp_min_stat, min_stat, GSS_C_MECH_CODE,
 105                            mech, &msg_ctx, &min_error_message);
 106
 107         maj_error_string = talloc_strndup(mem_ctx, (char *)maj_error_message.value, maj_error_message.length);
 108
 109         min_error_string = talloc_strndup(mem_ctx, (char *)min_error_message.value, min_error_message.length);
 110
 111         ret = talloc_asprintf(mem_ctx, "%s: %s", maj_error_string, min_error_string);
 112
 113         talloc_free(maj_error_string);
 114         talloc_free(min_error_string);
 115
 116         gss_release_buffer(&disp_min_stat, &maj_error_message);
 117         gss_release_buffer(&disp_min_stat, &min_error_message);
 118
 119         return ret;
 120 }
 121
 122
 123 static int gensec_gssapi_destructor(struct gensec_gssapi_state *gensec_gssapi_state)
 124 {
 125         OM_uint32 maj_stat, min_stat;
 126
 127         if (gensec_gssapi_state->delegated_cred_handle != GSS_C_NO_CREDENTIAL) {
 128                 maj_stat = gss_release_cred(&min_stat,
 129                                             &gensec_gssapi_state->delegated_cred_handle);
 130         }
 131
 132         if (gensec_gssapi_state->gssapi_context != GSS_C_NO_CONTEXT) {
 133                 maj_stat = gss_delete_sec_context (&min_stat,
 134                                                    &gensec_gssapi_state->gssapi_context,
 135                                                    GSS_C_NO_BUFFER);
 136         }
 137
 138         if (gensec_gssapi_state->server_name != GSS_C_NO_NAME) {
 139                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->server_name);
 140         }
 141         if (gensec_gssapi_state->client_name != GSS_C_NO_NAME) {
 142                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->client_name);
 143         }
 144         return 0;
 145 }
 146
 147 static NTSTATUS gensec_gssapi_start(struct gensec_security *gensec_security)
 148 {
 149         struct gensec_gssapi_state *gensec_gssapi_state;
 150         krb5_error_code ret;
 151         struct gsskrb5_send_to_kdc send_to_kdc;
 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                 = lp_parm_int(gensec_security->lp_ctx, NULL, "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
 171         /* TODO: Fill in channel bindings */
 172         gensec_gssapi_state->input_chan_bindings = GSS_C_NO_CHANNEL_BINDINGS;
 173
 174         gensec_gssapi_state->want_flags = 0;
 175         if (lp_parm_bool(gensec_security->lp_ctx, NULL, "gensec_gssapi", "mutual", true)) {
 176                 gensec_gssapi_state->want_flags |= GSS_C_MUTUAL_FLAG;
 177         }
 178         if (lp_parm_bool(gensec_security->lp_ctx, NULL, "gensec_gssapi", "delegation", true)) {
 179                 gensec_gssapi_state->want_flags |= GSS_C_DELEG_FLAG;
 180         }
 181         if (lp_parm_bool(gensec_security->lp_ctx, NULL, "gensec_gssapi", "replay", true)) {
 182                 gensec_gssapi_state->want_flags |= GSS_C_REPLAY_FLAG;
 183         }
 184         if (lp_parm_bool(gensec_security->lp_ctx, NULL, "gensec_gssapi", "sequence", true)) {
 185                 gensec_gssapi_state->want_flags |= GSS_C_SEQUENCE_FLAG;
 186         }
 187
 188         gensec_gssapi_state->got_flags = 0;
 189
 190         gensec_gssapi_state->session_key = data_blob(NULL, 0);
 191         gensec_gssapi_state->pac = data_blob(NULL, 0);
 192
 193         gensec_gssapi_state->delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 194
 195         talloc_set_destructor(gensec_gssapi_state, gensec_gssapi_destructor);
 196
 197         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 198                 gensec_gssapi_state->want_flags |= GSS_C_INTEG_FLAG;
 199         }
 200         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 201                 gensec_gssapi_state->want_flags |= GSS_C_CONF_FLAG;
 202         }
 203         if (gensec_security->want_features & GENSEC_FEATURE_DCE_STYLE) {
 204                 gensec_gssapi_state->want_flags |= GSS_C_DCE_STYLE;
 205         }
 206
 207         gensec_gssapi_state->gss_oid = GSS_C_NULL_OID;
 208
 209         send_to_kdc.func = smb_krb5_send_and_recv_func;
 210         send_to_kdc.ptr = gensec_security->event_ctx;
 211
 212         ret = gsskrb5_set_send_to_kdc(&send_to_kdc);
 213         if (ret) {
 214                 DEBUG(1,("gensec_krb5_start: gsskrb5_set_send_to_kdc failed\n"));
 215                 talloc_free(gensec_gssapi_state);
 216                 return NT_STATUS_INTERNAL_ERROR;
 217         }
 218         if (lp_realm(gensec_security->lp_ctx) && *lp_realm(gensec_security->lp_ctx)) {
 219                 char *upper_realm = strupper_talloc(gensec_gssapi_state, lp_realm(gensec_security->lp_ctx));
 220                 if (!upper_realm) {
 221                         DEBUG(1,("gensec_krb5_start: could not uppercase realm: %s\n", lp_realm(gensec_security->lp_ctx)));
 222                         talloc_free(gensec_gssapi_state);
 223                         return NT_STATUS_NO_MEMORY;
 224                 }
 225                 ret = gsskrb5_set_default_realm(upper_realm);
 226                 talloc_free(upper_realm);
 227                 if (ret) {
 228                         DEBUG(1,("gensec_krb5_start: gsskrb5_set_default_realm failed\n"));
 229                         talloc_free(gensec_gssapi_state);
 230                         return NT_STATUS_INTERNAL_ERROR;
 231                 }
 232         }
 233
 234         /* don't do DNS lookups of any kind, it might/will fail for a netbios name */
 235         ret = gsskrb5_set_dns_canonicalize(lp_parm_bool(gensec_security->lp_ctx, NULL, "krb5", "set_dns_canonicalize", false));
 236         if (ret) {
 237                 DEBUG(1,("gensec_krb5_start: gsskrb5_set_dns_canonicalize failed\n"));
 238                 talloc_free(gensec_gssapi_state);
 239                 return NT_STATUS_INTERNAL_ERROR;
 240         }
 241
 242         ret = smb_krb5_init_context(gensec_gssapi_state,
 243                                     gensec_security->event_ctx,
 244                                     gensec_security->lp_ctx,
 245                                     &gensec_gssapi_state->smb_krb5_context);
 246         if (ret) {
 247                 DEBUG(1,("gensec_krb5_start: krb5_init_context failed (%s)\n",
 248                          error_message(ret)));
 249                 talloc_free(gensec_gssapi_state);
 250                 return NT_STATUS_INTERNAL_ERROR;
 251         }
 252         return NT_STATUS_OK;
 253 }
 254
 255 static NTSTATUS gensec_gssapi_server_start(struct gensec_security *gensec_security)
 256 {
 257         NTSTATUS nt_status;
 258         int ret;
 259         struct gensec_gssapi_state *gensec_gssapi_state;
 260         struct cli_credentials *machine_account;
 261         struct gssapi_creds_container *gcc;
 262
 263         nt_status = gensec_gssapi_start(gensec_security);
 264         if (!NT_STATUS_IS_OK(nt_status)) {
 265                 return nt_status;
 266         }
 267
 268         gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 269
 270         machine_account = gensec_get_credentials(gensec_security);
 271
 272         if (!machine_account) {
 273                 DEBUG(3, ("No machine account credentials specified\n"));
 274                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 275         } else {
 276                 ret = cli_credentials_get_server_gss_creds(machine_account, gensec_security->lp_ctx, &gcc);
 277                 if (ret) {
 278                         DEBUG(1, ("Aquiring acceptor credentials failed: %s\n",
 279                                   error_message(ret)));
 280                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 281                 }
 282         }
 283
 284         gensec_gssapi_state->server_cred = gcc;
 285         return NT_STATUS_OK;
 286
 287 }
 288
 289 static NTSTATUS gensec_gssapi_sasl_server_start(struct gensec_security *gensec_security)
 290 {
 291         NTSTATUS nt_status;
 292         struct gensec_gssapi_state *gensec_gssapi_state;
 293         nt_status = gensec_gssapi_server_start(gensec_security);
 294
 295         if (NT_STATUS_IS_OK(nt_status)) {
 296                 gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 297                 gensec_gssapi_state->sasl = true;
 298         }
 299         return nt_status;
 300 }
 301
 302 static NTSTATUS gensec_gssapi_client_start(struct gensec_security *gensec_security)
 303 {
 304         struct gensec_gssapi_state *gensec_gssapi_state;
 305         struct cli_credentials *creds = gensec_get_credentials(gensec_security);
 306         krb5_error_code ret;
 307         NTSTATUS nt_status;
 308         gss_buffer_desc name_token;
 309         gss_OID name_type;
 310         OM_uint32 maj_stat, min_stat;
 311         const char *hostname = gensec_get_target_hostname(gensec_security);
 312         const char *principal;
 313         struct gssapi_creds_container *gcc;
 314
 315         if (!hostname) {
 316                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 317                 return NT_STATUS_INVALID_PARAMETER;
 318         }
 319         if (is_ipaddress(hostname)) {
 320                 DEBUG(2, ("Cannot do GSSAPI to an IP address\n"));
 321                 return NT_STATUS_INVALID_PARAMETER;
 322         }
 323         if (strcmp(hostname, "localhost") == 0) {
 324                 DEBUG(2, ("GSSAPI to 'localhost' does not make sense\n"));
 325                 return NT_STATUS_INVALID_PARAMETER;
 326         }
 327
 328         nt_status = gensec_gssapi_start(gensec_security);
 329         if (!NT_STATUS_IS_OK(nt_status)) {
 330                 return nt_status;
 331         }
 332
 333         gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 334
 335         gensec_gssapi_state->gss_oid = gss_mech_krb5;
 336
 337         principal = gensec_get_target_principal(gensec_security);
 338         if (principal && lp_client_use_spnego_principal(gensec_security->lp_ctx)) {
 339                 name_type = GSS_C_NULL_OID;
 340         } else {
 341                 principal = talloc_asprintf(gensec_gssapi_state, "%s@%s",
 342                                             gensec_get_target_service(gensec_security),
 343                                             hostname);
 344
 345                 name_type = GSS_C_NT_HOSTBASED_SERVICE;
 346         }
 347         name_token.value  = discard_const_p(uint8_t, principal);
 348         name_token.length = strlen(principal);
 349
 350
 351         maj_stat = gss_import_name (&min_stat,
 352                                     &name_token,
 353                                     name_type,
 354                                     &gensec_gssapi_state->server_name);
 355         if (maj_stat) {
 356                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 357                           (char *)name_token.value,
 358                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 359                 return NT_STATUS_INVALID_PARAMETER;
 360         }
 361
 362         ret = cli_credentials_get_client_gss_creds(creds, gensec_security->lp_ctx, &gcc);
 363         switch (ret) {
 364         case 0:
 365                 break;
 366         case KRB5KDC_ERR_PREAUTH_FAILED:
 367                 return NT_STATUS_LOGON_FAILURE;
 368         case KRB5_KDC_UNREACH:
 369                 DEBUG(3, ("Cannot reach a KDC we require to contact %s\n", principal));
 370                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 371         default:
 372                 DEBUG(1, ("Aquiring initiator credentials failed\n"));
 373                 return NT_STATUS_UNSUCCESSFUL;
 374         }
 375
 376         gensec_gssapi_state->client_cred = gcc;
 377         if (!talloc_reference(gensec_gssapi_state, gcc)) {
 378                 return NT_STATUS_NO_MEMORY;
 379         }
 380
 381         return NT_STATUS_OK;
 382 }
 383
 384 static NTSTATUS gensec_gssapi_sasl_client_start(struct gensec_security *gensec_security)
 385 {
 386         NTSTATUS nt_status;
 387         struct gensec_gssapi_state *gensec_gssapi_state;
 388         nt_status = gensec_gssapi_client_start(gensec_security);
 389
 390         if (NT_STATUS_IS_OK(nt_status)) {
 391                 gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 392                 gensec_gssapi_state->sasl = true;
 393         }
 394         return nt_status;
 395 }
 396
 397
 398 /**
 399  * Check if the packet is one for this mechansim
 400  *
 401  * @param gensec_security GENSEC state
 402  * @param in The request, as a DATA_BLOB
 403  * @return Error, INVALID_PARAMETER if it's not a packet for us
 404  *                or NT_STATUS_OK if the packet is ok.
 405  */
 406
 407 static NTSTATUS gensec_gssapi_magic(struct gensec_security *gensec_security,
 408                                     const DATA_BLOB *in)
 409 {
 410         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 411                 return NT_STATUS_OK;
 412         } else {
 413                 return NT_STATUS_INVALID_PARAMETER;
 414         }
 415 }
 416
 417
 418 /**
 419  * Next state function for the GSSAPI GENSEC mechanism
 420  *
 421  * @param gensec_gssapi_state GSSAPI State
 422  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 423  * @param in The request, as a DATA_BLOB
 424  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 425  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 426  *                or NT_STATUS_OK if the user is authenticated.
 427  */
 428
 429 static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 430                                    TALLOC_CTX *out_mem_ctx,
 431                                    const DATA_BLOB in, DATA_BLOB *out)
 432 {
 433         struct gensec_gssapi_state *gensec_gssapi_state
 434                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 435         NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
 436         OM_uint32 maj_stat, min_stat;
 437         OM_uint32 min_stat2;
 438         gss_buffer_desc input_token, output_token;
 439         gss_OID gss_oid_p = NULL;
 440         input_token.length = in.length;
 441         input_token.value = in.data;
 442
 443         switch (gensec_gssapi_state->sasl_state) {
 444         case STAGE_GSS_NEG:
 445         {
 446                 switch (gensec_security->gensec_role) {
 447                 case GENSEC_CLIENT:
 448                 {
 449                         maj_stat = gss_init_sec_context(&min_stat,
 450                                                         gensec_gssapi_state->client_cred->creds,
 451                                                         &gensec_gssapi_state->gssapi_context,
 452                                                         gensec_gssapi_state->server_name,
 453                                                         gensec_gssapi_state->gss_oid,
 454                                                         gensec_gssapi_state->want_flags,
 455                                                         0,
 456                                                         gensec_gssapi_state->input_chan_bindings,
 457                                                         &input_token,
 458                                                         &gss_oid_p,
 459                                                         &output_token,
 460                                                         &gensec_gssapi_state->got_flags, /* ret flags */
 461                                                         NULL);
 462                         if (gss_oid_p) {
 463                                 gensec_gssapi_state->gss_oid = gss_oid_p;
 464                         }
 465                         break;
 466                 }
 467                 case GENSEC_SERVER:
 468                 {
 469                         maj_stat = gss_accept_sec_context(&min_stat,
 470                                                           &gensec_gssapi_state->gssapi_context,
 471                                                           gensec_gssapi_state->server_cred->creds,
 472                                                           &input_token,
 473                                                           gensec_gssapi_state->input_chan_bindings,
 474                                                           &gensec_gssapi_state->client_name,
 475                                                           &gss_oid_p,
 476                                                           &output_token,
 477                                                           &gensec_gssapi_state->got_flags,
 478                                                           NULL,
 479                                                           &gensec_gssapi_state->delegated_cred_handle);
 480                         if (gss_oid_p) {
 481                                 gensec_gssapi_state->gss_oid = gss_oid_p;
 482                         }
 483                         break;
 484                 }
 485                 default:
 486                         return NT_STATUS_INVALID_PARAMETER;
 487
 488                 }
 489
 490                 gensec_gssapi_state->gss_exchange_count++;
 491
 492                 if (maj_stat == GSS_S_COMPLETE) {
 493                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 494                         gss_release_buffer(&min_stat2, &output_token);
 495
 496                         if (gensec_gssapi_state->got_flags & GSS_C_DELEG_FLAG) {
 497                                 DEBUG(5, ("gensec_gssapi: credentials were delegated\n"));
 498                         } else {
 499                                 DEBUG(5, ("gensec_gssapi: NO credentials were delegated\n"));
 500                         }
 501
 502                         /* We may have been invoked as SASL, so there
 503                          * is more work to do */
 504                         if (gensec_gssapi_state->sasl) {
 505                                 /* Due to a very subtle interaction
 506                                  * with SASL and the LDAP libs, we
 507                                  * must ensure the data pointer is
 508                                  * != NULL, but the length is 0.
 509                                  *
 510                                  * This ensures we send a 'zero
 511                                  * length' (rather than NULL) response
 512                                  */
 513
 514                                 if (!out->data) {
 515                                         out->data = (uint8_t *)talloc_strdup(out_mem_ctx, "\0");
 516                                 }
 517
 518                                 gensec_gssapi_state->sasl_state = STAGE_SASL_SSF_NEG;
 519                                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 520                         } else {
 521                                 gensec_gssapi_state->sasl_state = STAGE_DONE;
 522
 523                                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 524                                         DEBUG(5, ("GSSAPI Connection will be cryptographicly sealed\n"));
 525                                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 526                                         DEBUG(5, ("GSSAPI Connection will be cryptographicly signed\n"));
 527                                 } else {
 528                                         DEBUG(5, ("GSSAPI Connection will have no cryptographic protection\n"));
 529                                 }
 530
 531                                 return NT_STATUS_OK;
 532                         }
 533                 } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 534                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 535                         gss_release_buffer(&min_stat2, &output_token);
 536
 537                         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 538                 } else if (gss_oid_equal(gensec_gssapi_state->gss_oid, gss_mech_krb5)) {
 539                         switch (min_stat) {
 540                         case KRB5_KDC_UNREACH:
 541                                 DEBUG(3, ("Cannot reach a KDC we require: %s\n",
 542                                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 543                                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 544                         case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 545                                 DEBUG(3, ("Server is not registered with our KDC: %s\n",
 546                                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 547                                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 548                         case KRB5KRB_AP_ERR_MSG_TYPE:
 549                                 /* garbage input, possibly from the auto-mech detection */
 550                                 return NT_STATUS_INVALID_PARAMETER;
 551                         default:
 552                                 DEBUG(1, ("GSS Update(krb5)(%d) Update failed: %s\n",
 553                                           gensec_gssapi_state->gss_exchange_count,
 554                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 555                                 return nt_status;
 556                         }
 557                 } else {
 558                         DEBUG(1, ("GSS Update(%d) failed: %s\n",
 559                                   gensec_gssapi_state->gss_exchange_count,
 560                                   gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 561                         return nt_status;
 562                 }
 563                 break;
 564         }
 565
 566         /* These last two stages are only done if we were invoked as SASL */
 567         case STAGE_SASL_SSF_NEG:
 568         {
 569                 switch (gensec_security->gensec_role) {
 570                 case GENSEC_CLIENT:
 571                 {
 572                         uint8_t maxlength_proposed[4];
 573                         uint8_t maxlength_accepted[4];
 574                         uint8_t security_supported;
 575                         int conf_state;
 576                         gss_qop_t qop_state;
 577                         input_token.length = in.length;
 578                         input_token.value = in.data;
 579
 580                         /* As a client, we have just send a
 581                          * zero-length blob to the server (after the
 582                          * normal GSSAPI exchange), and it has replied
 583                          * with it's SASL negotiation */
 584
 585                         maj_stat = gss_unwrap(&min_stat,
 586                                               gensec_gssapi_state->gssapi_context,
 587                                               &input_token,
 588                                               &output_token,
 589                                               &conf_state,
 590                                               &qop_state);
 591                         if (GSS_ERROR(maj_stat)) {
 592                                 DEBUG(1, ("gensec_gssapi_update: GSS UnWrap of SASL protection negotiation failed: %s\n",
 593                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 594                                 return NT_STATUS_ACCESS_DENIED;
 595                         }
 596
 597                         if (output_token.length < 4) {
 598                                 return NT_STATUS_INVALID_PARAMETER;
 599                         }
 600
 601                         memcpy(maxlength_proposed, output_token.value, 4);
 602                         gss_release_buffer(&min_stat, &output_token);
 603
 604                         /* first byte is the proposed security */
 605                         security_supported = maxlength_proposed[0];
 606                         maxlength_proposed[0] = '\0';
 607
 608                         /* Rest is the proposed max wrap length */
 609                         gensec_gssapi_state->max_wrap_buf_size = MIN(RIVAL(maxlength_proposed, 0),
 610                                                                      gensec_gssapi_state->max_wrap_buf_size);
 611                         gensec_gssapi_state->sasl_protection = 0;
 612                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 613                                 if (security_supported & NEG_SEAL) {
 614                                         gensec_gssapi_state->sasl_protection |= NEG_SEAL;
 615                                 }
 616                         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 617                                 if (security_supported & NEG_SIGN) {
 618                                         gensec_gssapi_state->sasl_protection |= NEG_SIGN;
 619                                 }
 620                         } else if (security_supported & NEG_NONE) {
 621                                 gensec_gssapi_state->sasl_protection |= NEG_NONE;
 622                         } else {
 623                                 DEBUG(1, ("Remote server does not support unprotected connections"));
 624                                 return NT_STATUS_ACCESS_DENIED;
 625                         }
 626
 627                         /* Send back the negotiated max length */
 628
 629                         RSIVAL(maxlength_accepted, 0, gensec_gssapi_state->max_wrap_buf_size);
 630
 631                         maxlength_accepted[0] = gensec_gssapi_state->sasl_protection;
 632
 633                         input_token.value = maxlength_accepted;
 634                         input_token.length = sizeof(maxlength_accepted);
 635
 636                         maj_stat = gss_wrap(&min_stat,
 637                                             gensec_gssapi_state->gssapi_context,
 638                                             false,
 639                                             GSS_C_QOP_DEFAULT,
 640                                             &input_token,
 641                                             &conf_state,
 642                                             &output_token);
 643                         if (GSS_ERROR(maj_stat)) {
 644                                 DEBUG(1, ("GSS Update(SSF_NEG): GSS Wrap failed: %s\n",
 645                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 646                                 return NT_STATUS_ACCESS_DENIED;
 647                         }
 648
 649                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 650                         gss_release_buffer(&min_stat, &output_token);
 651
 652                         /* quirk:  This changes the value that gensec_have_feature returns, to be that after SASL negotiation */
 653                         gensec_gssapi_state->sasl_state = STAGE_DONE;
 654
 655                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 656                                 DEBUG(3, ("SASL/GSSAPI Connection to server will be cryptographicly sealed\n"));
 657                         } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 658                                 DEBUG(3, ("SASL/GSSAPI Connection to server will be cryptographicly signed\n"));
 659                         } else {
 660                                 DEBUG(3, ("SASL/GSSAPI Connection to server will have no cryptographicly protection\n"));
 661                         }
 662
 663                         return NT_STATUS_OK;
 664                 }
 665                 case GENSEC_SERVER:
 666                 {
 667                         uint8_t maxlength_proposed[4];
 668                         uint8_t security_supported = 0x0;
 669                         int conf_state;
 670
 671                         /* As a server, we have just been sent a zero-length blob (note this, but it isn't fatal) */
 672                         if (in.length != 0) {
 673                                 DEBUG(1, ("SASL/GSSAPI: client sent non-zero length starting SASL negotiation!\n"));
 674                         }
 675
 676                         /* Give the client some idea what we will support */
 677
 678                         RSIVAL(maxlength_proposed, 0, gensec_gssapi_state->max_wrap_buf_size);
 679                         /* first byte is the proposed security */
 680                         maxlength_proposed[0] = '\0';
 681
 682                         gensec_gssapi_state->sasl_protection = 0;
 683                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 684                                 security_supported |= NEG_SEAL;
 685                         }
 686                         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 687                                 security_supported |= NEG_SIGN;
 688                         }
 689                         if (security_supported == 0) {
 690                                 /* If we don't support anything, this must be 0 */
 691                                 RSIVAL(maxlength_proposed, 0, 0x0);
 692                         }
 693
 694                         /* TODO:  We may not wish to support this */
 695                         security_supported |= NEG_NONE;
 696                         maxlength_proposed[0] = security_supported;
 697
 698                         input_token.value = maxlength_proposed;
 699                         input_token.length = sizeof(maxlength_proposed);
 700
 701                         maj_stat = gss_wrap(&min_stat,
 702                                             gensec_gssapi_state->gssapi_context,
 703                                             false,
 704                                             GSS_C_QOP_DEFAULT,
 705                                             &input_token,
 706                                             &conf_state,
 707                                             &output_token);
 708                         if (GSS_ERROR(maj_stat)) {
 709                                 DEBUG(1, ("GSS Update(SSF_NEG): GSS Wrap failed: %s\n",
 710                                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 711                                 return NT_STATUS_ACCESS_DENIED;
 712                         }
 713
 714                         *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 715                         gss_release_buffer(&min_stat, &output_token);
 716
 717                         gensec_gssapi_state->sasl_state = STAGE_SASL_SSF_ACCEPT;
 718                         return NT_STATUS_MORE_PROCESSING_REQUIRED;
 719                 }
 720                 default:
 721                         return NT_STATUS_INVALID_PARAMETER;
 722
 723                 }
 724         }
 725         /* This is s server-only stage */
 726         case STAGE_SASL_SSF_ACCEPT:
 727         {
 728                 uint8_t maxlength_accepted[4];
 729                 uint8_t security_accepted;
 730                 int conf_state;
 731                 gss_qop_t qop_state;
 732                 input_token.length = in.length;
 733                 input_token.value = in.data;
 734
 735                 maj_stat = gss_unwrap(&min_stat,
 736                                       gensec_gssapi_state->gssapi_context,
 737                                       &input_token,
 738                                       &output_token,
 739                                       &conf_state,
 740                                       &qop_state);
 741                 if (GSS_ERROR(maj_stat)) {
 742                         DEBUG(1, ("gensec_gssapi_update: GSS UnWrap of SASL protection negotiation failed: %s\n",
 743                                   gssapi_error_string(out_mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 744                         return NT_STATUS_ACCESS_DENIED;
 745                 }
 746
 747                 if (output_token.length < 4) {
 748                         return NT_STATUS_INVALID_PARAMETER;
 749                 }
 750
 751                 memcpy(maxlength_accepted, output_token.value, 4);
 752                 gss_release_buffer(&min_stat, &output_token);
 753
 754                 /* first byte is the proposed security */
 755                 security_accepted = maxlength_accepted[0];
 756                 maxlength_accepted[0] = '\0';
 757
 758                 /* Rest is the proposed max wrap length */
 759                 gensec_gssapi_state->max_wrap_buf_size = MIN(RIVAL(maxlength_accepted, 0),
 760                                                              gensec_gssapi_state->max_wrap_buf_size);
 761
 762                 gensec_gssapi_state->sasl_protection = 0;
 763                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 764                         if (security_accepted & NEG_SEAL) {
 765                                 gensec_gssapi_state->sasl_protection |= NEG_SEAL;
 766                         }
 767                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 768                         if (security_accepted & NEG_SIGN) {
 769                                 gensec_gssapi_state->sasl_protection |= NEG_SIGN;
 770                         }
 771                 } else if (security_accepted & NEG_NONE) {
 772                         gensec_gssapi_state->sasl_protection |= NEG_NONE;
 773                 } else {
 774                         DEBUG(1, ("Remote client does not support unprotected connections, but we failed to negotiate anything better"));
 775                         return NT_STATUS_ACCESS_DENIED;
 776                 }
 777
 778                 /* quirk:  This changes the value that gensec_have_feature returns, to be that after SASL negotiation */
 779                 gensec_gssapi_state->sasl_state = STAGE_DONE;
 780                 if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) {
 781                         DEBUG(5, ("SASL/GSSAPI Connection from client will be cryptographicly sealed\n"));
 782                 } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) {
 783                         DEBUG(5, ("SASL/GSSAPI Connection from client will be cryptographicly signed\n"));
 784                 } else {
 785                         DEBUG(5, ("SASL/GSSAPI Connection from client will have no cryptographic protection\n"));
 786                 }
 787
 788                 *out = data_blob(NULL, 0);
 789                 return NT_STATUS_OK;
 790         }
 791         default:
 792                 return NT_STATUS_INVALID_PARAMETER;
 793         }
 794 }
 795
 796 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 797                                    TALLOC_CTX *mem_ctx,
 798                                    const DATA_BLOB *in,
 799                                    DATA_BLOB *out)
 800 {
 801         struct gensec_gssapi_state *gensec_gssapi_state
 802                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 803         OM_uint32 maj_stat, min_stat;
 804         gss_buffer_desc input_token, output_token;
 805         int conf_state;
 806         input_token.length = in->length;
 807         input_token.value = in->data;
 808
 809         maj_stat = gss_wrap(&min_stat,
 810                             gensec_gssapi_state->gssapi_context,
 811                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 812                             GSS_C_QOP_DEFAULT,
 813                             &input_token,
 814                             &conf_state,
 815                             &output_token);
 816         if (GSS_ERROR(maj_stat)) {
 817                 DEBUG(1, ("gensec_gssapi_wrap: GSS Wrap failed: %s\n",
 818                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 819                 return NT_STATUS_ACCESS_DENIED;
 820         }
 821
 822         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 823         gss_release_buffer(&min_stat, &output_token);
 824
 825         if (gensec_gssapi_state->sasl) {
 826                 size_t max_wrapped_size = gensec_gssapi_max_wrapped_size(gensec_security);
 827                 if (max_wrapped_size < out->length) {
 828                         DEBUG(1, ("gensec_gssapi_wrap: when wrapped, INPUT data (%u) is grew to be larger than SASL negotiated maximum output size (%u > %u)\n",
 829                                   (unsigned)in->length,
 830                                   (unsigned)out->length,
 831                                   (unsigned int)max_wrapped_size));
 832                         return NT_STATUS_INVALID_PARAMETER;
 833                 }
 834         }
 835
 836         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 837             && !conf_state) {
 838                 return NT_STATUS_ACCESS_DENIED;
 839         }
 840         return NT_STATUS_OK;
 841 }
 842
 843 static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 844                                      TALLOC_CTX *mem_ctx,
 845                                      const DATA_BLOB *in,
 846                                      DATA_BLOB *out)
 847 {
 848         struct gensec_gssapi_state *gensec_gssapi_state
 849                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 850         OM_uint32 maj_stat, min_stat;
 851         gss_buffer_desc input_token, output_token;
 852         int conf_state;
 853         gss_qop_t qop_state;
 854         input_token.length = in->length;
 855         input_token.value = in->data;
 856
 857         if (gensec_gssapi_state->sasl) {
 858                 size_t max_wrapped_size = gensec_gssapi_max_wrapped_size(gensec_security);
 859                 if (max_wrapped_size < in->length) {
 860                         DEBUG(1, ("gensec_gssapi_unwrap: WRAPPED data is larger than SASL negotiated maximum size\n"));
 861                         return NT_STATUS_INVALID_PARAMETER;
 862                 }
 863         }
 864
 865         maj_stat = gss_unwrap(&min_stat,
 866                               gensec_gssapi_state->gssapi_context,
 867                               &input_token,
 868                               &output_token,
 869                               &conf_state,
 870                               &qop_state);
 871         if (GSS_ERROR(maj_stat)) {
 872                 DEBUG(1, ("gensec_gssapi_unwrap: GSS UnWrap failed: %s\n",
 873                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 874                 return NT_STATUS_ACCESS_DENIED;
 875         }
 876
 877         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 878         gss_release_buffer(&min_stat, &output_token);
 879
 880         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 881             && !conf_state) {
 882                 return NT_STATUS_ACCESS_DENIED;
 883         }
 884         return NT_STATUS_OK;
 885 }
 886
 887 /* Find out the maximum input size negotiated on this connection */
 888
 889 static size_t gensec_gssapi_max_input_size(struct gensec_security *gensec_security)
 890 {
 891         struct gensec_gssapi_state *gensec_gssapi_state
 892                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 893         OM_uint32 maj_stat, min_stat;
 894         OM_uint32 max_input_size;
 895
 896         maj_stat = gss_wrap_size_limit(&min_stat,
 897                                        gensec_gssapi_state->gssapi_context,
 898                                        gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 899                                        GSS_C_QOP_DEFAULT,
 900                                        gensec_gssapi_state->max_wrap_buf_size,
 901                                        &max_input_size);
 902         if (GSS_ERROR(maj_stat)) {
 903                 TALLOC_CTX *mem_ctx = talloc_new(NULL);
 904                 DEBUG(1, ("gensec_gssapi_max_input_size: determinaing signature size with gss_wrap_size_limit failed: %s\n",
 905                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 906                 talloc_free(mem_ctx);
 907                 return 0;
 908         }
 909
 910         return max_input_size;
 911 }
 912
 913 /* Find out the maximum output size negotiated on this connection */
 914 static size_t gensec_gssapi_max_wrapped_size(struct gensec_security *gensec_security)
 915 {
 916         struct gensec_gssapi_state *gensec_gssapi_state = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);;
 917         return gensec_gssapi_state->max_wrap_buf_size;
 918 }
 919
 920 static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_security,
 921                                           TALLOC_CTX *mem_ctx,
 922                                           uint8_t *data, size_t length,
 923                                           const uint8_t *whole_pdu, size_t pdu_length,
 924                                           DATA_BLOB *sig)
 925 {
 926         struct gensec_gssapi_state *gensec_gssapi_state
 927                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 928         OM_uint32 maj_stat, min_stat;
 929         gss_buffer_desc input_token, output_token;
 930         int conf_state;
 931         ssize_t sig_length;
 932
 933         input_token.length = length;
 934         input_token.value = data;
 935
 936         maj_stat = gss_wrap(&min_stat,
 937                             gensec_gssapi_state->gssapi_context,
 938                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 939                             GSS_C_QOP_DEFAULT,
 940                             &input_token,
 941                             &conf_state,
 942                             &output_token);
 943         if (GSS_ERROR(maj_stat)) {
 944                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap failed: %s\n",
 945                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
 946                 return NT_STATUS_ACCESS_DENIED;
 947         }
 948
 949         if (output_token.length < input_token.length) {
 950                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap length [%ld] *less* than caller length [%ld]\n",
 951                           (long)output_token.length, (long)length));
 952                 return NT_STATUS_INTERNAL_ERROR;
 953         }
 954         sig_length = output_token.length - input_token.length;
 955
 956         memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);
 957         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 958
 959         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 960         dump_data_pw("gensec_gssapi_seal_packet: clear\n", data, length);
 961         dump_data_pw("gensec_gssapi_seal_packet: sealed\n", ((uint8_t *)output_token.value) + sig_length, output_token.length - sig_length);
 962
 963         gss_release_buffer(&min_stat, &output_token);
 964
 965         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 966             && !conf_state) {
 967                 return NT_STATUS_ACCESS_DENIED;
 968         }
 969         return NT_STATUS_OK;
 970 }
 971
 972 static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_security,
 973                                             TALLOC_CTX *mem_ctx,
 974                                             uint8_t *data, size_t length,
 975                                             const uint8_t *whole_pdu, size_t pdu_length,
 976                                             const DATA_BLOB *sig)
 977 {
 978         struct gensec_gssapi_state *gensec_gssapi_state
 979                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
 980         OM_uint32 maj_stat, min_stat;
 981         gss_buffer_desc input_token, output_token;
 982         int conf_state;
 983         gss_qop_t qop_state;
 984         DATA_BLOB in;
 985
 986         dump_data_pw("gensec_gssapi_unseal_packet: sig\n", sig->data, sig->length);
 987
 988         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 989
 990         memcpy(in.data, sig->data, sig->length);
 991         memcpy(in.data + sig->length, data, length);
 992
 993         input_token.length = in.length;
 994         input_token.value = in.data;
 995
 996         maj_stat = gss_unwrap(&min_stat,
 997                               gensec_gssapi_state->gssapi_context,
 998                               &input_token,
 999                               &output_token,
1000                               &conf_state,
1001                               &qop_state);
1002         if (GSS_ERROR(maj_stat)) {
1003                 DEBUG(1, ("gensec_gssapi_unseal_packet: GSS UnWrap failed: %s\n",
1004                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1005                 return NT_STATUS_ACCESS_DENIED;
1006         }
1007
1008         if (output_token.length != length) {
1009                 return NT_STATUS_INTERNAL_ERROR;
1010         }
1011
1012         memcpy(data, output_token.value, length);
1013
1014         gss_release_buffer(&min_stat, &output_token);
1015
1016         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
1017             && !conf_state) {
1018                 return NT_STATUS_ACCESS_DENIED;
1019         }
1020         return NT_STATUS_OK;
1021 }
1022
1023 static NTSTATUS gensec_gssapi_sign_packet(struct gensec_security *gensec_security,
1024                                           TALLOC_CTX *mem_ctx,
1025                                           const uint8_t *data, size_t length,
1026                                           const uint8_t *whole_pdu, size_t pdu_length,
1027                                           DATA_BLOB *sig)
1028 {
1029         struct gensec_gssapi_state *gensec_gssapi_state
1030                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1031         OM_uint32 maj_stat, min_stat;
1032         gss_buffer_desc input_token, output_token;
1033         int conf_state;
1034         ssize_t sig_length = 0;
1035
1036         input_token.length = length;
1037         input_token.value = discard_const_p(uint8_t *, data);
1038
1039         maj_stat = gss_wrap(&min_stat,
1040                             gensec_gssapi_state->gssapi_context,
1041                             0,
1042                             GSS_C_QOP_DEFAULT,
1043                             &input_token,
1044                             &conf_state,
1045                             &output_token);
1046         if (GSS_ERROR(maj_stat)) {
1047                 DEBUG(1, ("GSS Wrap failed: %s\n",
1048                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1049                 return NT_STATUS_ACCESS_DENIED;
1050         }
1051
1052         if (output_token.length < input_token.length) {
1053                 DEBUG(1, ("gensec_gssapi_sign_packet: GSS Wrap length [%ld] *less* than caller length [%ld]\n",
1054                           (long)output_token.length, (long)length));
1055                 return NT_STATUS_INTERNAL_ERROR;
1056         }
1057
1058         /* Caller must pad to right boundary */
1059         sig_length = output_token.length - input_token.length;
1060
1061         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
1062
1063         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
1064
1065         gss_release_buffer(&min_stat, &output_token);
1066
1067         return NT_STATUS_OK;
1068 }
1069
1070 static NTSTATUS gensec_gssapi_check_packet(struct gensec_security *gensec_security,
1071                                            TALLOC_CTX *mem_ctx,
1072                                            const uint8_t *data, size_t length,
1073                                            const uint8_t *whole_pdu, size_t pdu_length,
1074                                            const DATA_BLOB *sig)
1075 {
1076         struct gensec_gssapi_state *gensec_gssapi_state
1077                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1078         OM_uint32 maj_stat, min_stat;
1079         gss_buffer_desc input_token, output_token;
1080         int conf_state;
1081         gss_qop_t qop_state;
1082         DATA_BLOB in;
1083
1084         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
1085
1086         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
1087
1088         memcpy(in.data, sig->data, sig->length);
1089         memcpy(in.data + sig->length, data, length);
1090
1091         input_token.length = in.length;
1092         input_token.value = in.data;
1093
1094         maj_stat = gss_unwrap(&min_stat,
1095                               gensec_gssapi_state->gssapi_context,
1096                               &input_token,
1097                               &output_token,
1098                               &conf_state,
1099                               &qop_state);
1100         if (GSS_ERROR(maj_stat)) {
1101                 DEBUG(1, ("GSS UnWrap failed: %s\n",
1102                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1103                 return NT_STATUS_ACCESS_DENIED;
1104         }
1105
1106         if (output_token.length != length) {
1107                 return NT_STATUS_INTERNAL_ERROR;
1108         }
1109
1110         gss_release_buffer(&min_stat, &output_token);
1111
1112         return NT_STATUS_OK;
1113 }
1114
1115 /* Try to figure out what features we actually got on the connection */
1116 static bool gensec_gssapi_have_feature(struct gensec_security *gensec_security,
1117                                        uint32_t feature)
1118 {
1119         struct gensec_gssapi_state *gensec_gssapi_state
1120                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1121         if (feature & GENSEC_FEATURE_SIGN) {
1122                 /* If we are going GSSAPI SASL, then we honour the second negotiation */
1123                 if (gensec_gssapi_state->sasl
1124                     && gensec_gssapi_state->sasl_state == STAGE_DONE) {
1125                         return ((gensec_gssapi_state->sasl_protection & NEG_SIGN)
1126                                 && (gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG));
1127                 }
1128                 return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
1129         }
1130         if (feature & GENSEC_FEATURE_SEAL) {
1131                 /* If we are going GSSAPI SASL, then we honour the second negotiation */
1132                 if (gensec_gssapi_state->sasl
1133                     && gensec_gssapi_state->sasl_state == STAGE_DONE) {
1134                         return ((gensec_gssapi_state->sasl_protection & NEG_SEAL)
1135                                  && (gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG));
1136                 }
1137                 return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
1138         }
1139         if (feature & GENSEC_FEATURE_SESSION_KEY) {
1140                 /* Only for GSSAPI/Krb5 */
1141                 if (gss_oid_equal(gensec_gssapi_state->gss_oid, gss_mech_krb5)) {
1142                         return true;
1143                 }
1144         }
1145         if (feature & GENSEC_FEATURE_DCE_STYLE) {
1146                 return gensec_gssapi_state->got_flags & GSS_C_DCE_STYLE;
1147         }
1148         /* We can always do async (rather than strict request/reply) packets.  */
1149         if (feature & GENSEC_FEATURE_ASYNC_REPLIES) {
1150                 return true;
1151         }
1152         return false;
1153 }
1154
1155 /*
1156  * Extract the 'sesssion key' needed by SMB signing and ncacn_np
1157  * (for encrypting some passwords).
1158  *
1159  * This breaks all the abstractions, but what do you expect...
1160  */
1161 static NTSTATUS gensec_gssapi_session_key(struct gensec_security *gensec_security,
1162                                           DATA_BLOB *session_key)
1163 {
1164         struct gensec_gssapi_state *gensec_gssapi_state
1165                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1166         OM_uint32 maj_stat, min_stat;
1167         krb5_keyblock *subkey;
1168
1169         if (gensec_gssapi_state->session_key.data) {
1170                 *session_key = gensec_gssapi_state->session_key;
1171                 return NT_STATUS_OK;
1172         }
1173
1174         maj_stat = gsskrb5_get_initiator_subkey(&min_stat,
1175                                                 gensec_gssapi_state->gssapi_context,
1176                                                 &subkey);
1177         if (maj_stat != 0) {
1178                 DEBUG(1, ("NO session key for this mech\n"));
1179                 return NT_STATUS_NO_USER_SESSION_KEY;
1180         }
1181
1182         DEBUG(10, ("Got KRB5 session key of length %d\n",
1183                    (int)KRB5_KEY_LENGTH(subkey)));
1184         gensec_gssapi_state->session_key = data_blob_talloc(gensec_gssapi_state,
1185                                                             KRB5_KEY_DATA(subkey), KRB5_KEY_LENGTH(subkey));
1186         krb5_free_keyblock(gensec_gssapi_state->smb_krb5_context->krb5_context, subkey);
1187         *session_key = gensec_gssapi_state->session_key;
1188         dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
1189
1190         return NT_STATUS_OK;
1191 }
1192
1193 /* Get some basic (and authorization) information about the user on
1194  * this session.  This uses either the PAC (if present) or a local
1195  * database lookup */
1196 static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_security,
1197                                            struct auth_session_info **_session_info)
1198 {
1199         NTSTATUS nt_status;
1200         TALLOC_CTX *mem_ctx;
1201         struct gensec_gssapi_state *gensec_gssapi_state
1202                 = talloc_get_type(gensec_security->private_data, struct gensec_gssapi_state);
1203         struct auth_serversupplied_info *server_info = NULL;
1204         struct auth_session_info *session_info = NULL;
1205         struct PAC_LOGON_INFO *logon_info;
1206         OM_uint32 maj_stat, min_stat;
1207         gss_buffer_desc name_token;
1208         gss_buffer_desc pac;
1209         krb5_keyblock *keyblock;
1210         time_t authtime;
1211         krb5_principal principal;
1212         char *principal_string;
1213         DATA_BLOB pac_blob;
1214
1215         if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
1216             || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
1217                        gensec_gssapi_state->gss_oid->length) != 0)) {
1218                 DEBUG(1, ("NO session info available for this mech\n"));
1219                 return NT_STATUS_INVALID_PARAMETER;
1220         }
1221
1222         mem_ctx = talloc_named(gensec_gssapi_state, 0, "gensec_gssapi_session_info context");
1223         NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
1224
1225         maj_stat = gss_display_name (&min_stat,
1226                                      gensec_gssapi_state->client_name,
1227                                      &name_token,
1228                                      NULL);
1229         if (GSS_ERROR(maj_stat)) {
1230                 DEBUG(1, ("GSS display_name failed: %s\n",
1231                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1232                 talloc_free(mem_ctx);
1233                 return NT_STATUS_FOOBAR;
1234         }
1235
1236         principal_string = talloc_strndup(mem_ctx,
1237                                           (const char *)name_token.value,
1238                                           name_token.length);
1239
1240         gss_release_buffer(&min_stat, &name_token);
1241
1242         if (!principal_string) {
1243                 talloc_free(mem_ctx);
1244                 return NT_STATUS_NO_MEMORY;
1245         }
1246
1247         maj_stat = gsskrb5_extract_authz_data_from_sec_context(&min_stat,
1248                                                                gensec_gssapi_state->gssapi_context,
1249                                                                KRB5_AUTHDATA_WIN2K_PAC,
1250                                                                &pac);
1251
1252
1253         if (maj_stat == 0) {
1254                 pac_blob = data_blob_talloc(mem_ctx, pac.value, pac.length);
1255                 gss_release_buffer(&min_stat, &pac);
1256
1257         } else {
1258                 pac_blob = data_blob(NULL, 0);
1259         }
1260
1261         /* IF we have the PAC - otherwise we need to get this
1262          * data from elsewere - local ldb, or (TODO) lookup of some
1263          * kind...
1264          */
1265         if (pac_blob.length) {
1266                 krb5_error_code ret;
1267                 union netr_Validation validation;
1268
1269                 maj_stat = gsskrb5_extract_authtime_from_sec_context(&min_stat,
1270                                                                      gensec_gssapi_state->gssapi_context,
1271                                                                      &authtime);
1272
1273                 if (GSS_ERROR(maj_stat)) {
1274                         DEBUG(1, ("gsskrb5_extract_authtime_from_sec_context: %s\n",
1275                                   gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1276                         talloc_free(mem_ctx);
1277                         return NT_STATUS_FOOBAR;
1278                 }
1279
1280                 maj_stat = gsskrb5_extract_service_keyblock(&min_stat,
1281                                                             gensec_gssapi_state->gssapi_context,
1282                                                             &keyblock);
1283
1284                 if (GSS_ERROR(maj_stat)) {
1285                         DEBUG(1, ("gsskrb5_copy_service_keyblock failed: %s\n",
1286                                   gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1287                         talloc_free(mem_ctx);
1288                         return NT_STATUS_FOOBAR;
1289                 }
1290
1291                 ret = krb5_parse_name_flags(gensec_gssapi_state->smb_krb5_context->krb5_context,
1292                                             principal_string,
1293                                             KRB5_PRINCIPAL_PARSE_MUST_REALM,
1294                                             &principal);
1295                 if (ret) {
1296                         krb5_free_keyblock(gensec_gssapi_state->smb_krb5_context->krb5_context,
1297                                            keyblock);
1298                         talloc_free(mem_ctx);
1299                         return NT_STATUS_INVALID_PARAMETER;
1300                 }
1301
1302                 /* decode and verify the pac */
1303                 nt_status = kerberos_pac_logon_info(mem_ctx, lp_iconv_convenience(gensec_security->lp_ctx), &logon_info, pac_blob,
1304                                                     gensec_gssapi_state->smb_krb5_context->krb5_context,
1305                                                     NULL, keyblock, principal, authtime, NULL);
1306                 krb5_free_principal(gensec_gssapi_state->smb_krb5_context->krb5_context, principal);
1307                 krb5_free_keyblock(gensec_gssapi_state->smb_krb5_context->krb5_context,
1308                                    keyblock);
1309
1310                 if (!NT_STATUS_IS_OK(nt_status)) {
1311                         talloc_free(mem_ctx);
1312                         return nt_status;
1313                 }
1314                 validation.sam3 = &logon_info->info3;
1315                 nt_status = make_server_info_netlogon_validation(gensec_gssapi_state,
1316                                                                  NULL,
1317                                                                  3, &validation,
1318                                                                  &server_info);
1319                 if (!NT_STATUS_IS_OK(nt_status)) {
1320                         talloc_free(mem_ctx);
1321                         return nt_status;
1322                 }
1323         } else if (!lp_parm_bool(gensec_security->lp_ctx, NULL, "gensec", "require_pac", false)) {
1324                 DEBUG(1, ("Unable to find PAC, resorting to local user lookup: %s\n",
1325                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1326                 nt_status = sam_get_server_info_principal(mem_ctx, gensec_security->lp_ctx, principal_string,
1327                                                           &server_info);
1328
1329                 if (!NT_STATUS_IS_OK(nt_status)) {
1330                         talloc_free(mem_ctx);
1331                         return nt_status;
1332                 }
1333         } else {
1334                 DEBUG(1, ("Unable to find PAC in ticket from %s, failing to allow access: %s\n",
1335                           principal_string,
1336                           gssapi_error_string(mem_ctx, maj_stat, min_stat, gensec_gssapi_state->gss_oid)));
1337                 return NT_STATUS_ACCESS_DENIED;
1338         }
1339
1340         /* references the server_info into the session_info */
1341         nt_status = auth_generate_session_info(mem_ctx, gensec_security->lp_ctx, server_info, &session_info);
1342         if (!NT_STATUS_IS_OK(nt_status)) {
1343                 talloc_free(mem_ctx);
1344                 return nt_status;
1345         }
1346
1347         nt_status = gensec_gssapi_session_key(gensec_security, &session_info->session_key);
1348         if (!NT_STATUS_IS_OK(nt_status)) {
1349                 talloc_free(mem_ctx);
1350                 return nt_status;
1351         }
1352
1353         if (!(gensec_gssapi_state->got_flags & GSS_C_DELEG_FLAG)) {
1354                 DEBUG(10, ("gensec_gssapi: NO delegated credentials supplied by client\n"));
1355         } else {
1356                 krb5_error_code ret;
1357                 DEBUG(10, ("gensec_gssapi: delegated credentials supplied by client\n"));
1358                 session_info->credentials = cli_credentials_init(session_info);
1359                 if (!session_info->credentials) {
1360                         talloc_free(mem_ctx);
1361                         return NT_STATUS_NO_MEMORY;
1362                 }
1363
1364                 cli_credentials_set_event_context(session_info->credentials, gensec_security->event_ctx);
1365                 cli_credentials_set_conf(session_info->credentials, gensec_security->lp_ctx);
1366                 /* Just so we don't segfault trying to get at a username */
1367                 cli_credentials_set_anonymous(session_info->credentials);
1368
1369                 ret = cli_credentials_set_client_gss_creds(session_info->credentials,
1370                                                            gensec_security->lp_ctx,
1371                                                            gensec_gssapi_state->delegated_cred_handle,
1372                                                            CRED_SPECIFIED);
1373                 if (ret) {
1374                         talloc_free(mem_ctx);
1375                         return NT_STATUS_NO_MEMORY;
1376                 }
1377
1378                 /* This credential handle isn't useful for password authentication, so ensure nobody tries to do that */
1379                 cli_credentials_set_kerberos_state(session_info->credentials, CRED_MUST_USE_KERBEROS);
1380
1381                 /* It has been taken from this place... */
1382                 gensec_gssapi_state->delegated_cred_handle = GSS_C_NO_CREDENTIAL;
1383         }
1384         talloc_steal(gensec_gssapi_state, session_info);
1385         talloc_free(mem_ctx);
1386         *_session_info = session_info;
1387
1388         return NT_STATUS_OK;
1389 }
1390
1391 static const char *gensec_gssapi_krb5_oids[] = {
1392         GENSEC_OID_KERBEROS5_OLD,
1393         GENSEC_OID_KERBEROS5,
1394         NULL
1395 };
1396
1397 static const char *gensec_gssapi_spnego_oids[] = {
1398         GENSEC_OID_SPNEGO,
1399         NULL
1400 };
1401
1402 /* As a server, this could in theory accept any GSSAPI mech */
1403 static const struct gensec_security_ops gensec_gssapi_spnego_security_ops = {
1404         .name           = "gssapi_spnego",
1405         .sasl_name      = "GSS-SPNEGO",
1406         .auth_type      = DCERPC_AUTH_TYPE_SPNEGO,
1407         .oid            = gensec_gssapi_spnego_oids,
1408         .client_start   = gensec_gssapi_client_start,
1409         .server_start   = gensec_gssapi_server_start,
1410         .magic          = gensec_gssapi_magic,
1411         .update         = gensec_gssapi_update,
1412         .session_key    = gensec_gssapi_session_key,
1413         .session_info   = gensec_gssapi_session_info,
1414         .sign_packet    = gensec_gssapi_sign_packet,
1415         .check_packet   = gensec_gssapi_check_packet,
1416         .seal_packet    = gensec_gssapi_seal_packet,
1417         .unseal_packet  = gensec_gssapi_unseal_packet,
1418         .wrap           = gensec_gssapi_wrap,
1419         .unwrap         = gensec_gssapi_unwrap,
1420         .have_feature   = gensec_gssapi_have_feature,
1421         .enabled        = false,
1422         .kerberos       = true,
1423         .priority       = GENSEC_GSSAPI
1424 };
1425
1426 /* As a server, this could in theory accept any GSSAPI mech */
1427 static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
1428         .name           = "gssapi_krb5",
1429         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
1430         .oid            = gensec_gssapi_krb5_oids,
1431         .client_start   = gensec_gssapi_client_start,
1432         .server_start   = gensec_gssapi_server_start,
1433         .magic          = gensec_gssapi_magic,
1434         .update         = gensec_gssapi_update,
1435         .session_key    = gensec_gssapi_session_key,
1436         .session_info   = gensec_gssapi_session_info,
1437         .sign_packet    = gensec_gssapi_sign_packet,
1438         .check_packet   = gensec_gssapi_check_packet,
1439         .seal_packet    = gensec_gssapi_seal_packet,
1440         .unseal_packet  = gensec_gssapi_unseal_packet,
1441         .wrap           = gensec_gssapi_wrap,
1442         .unwrap         = gensec_gssapi_unwrap,
1443         .have_feature   = gensec_gssapi_have_feature,
1444         .enabled        = true,
1445         .kerberos       = true,
1446         .priority       = GENSEC_GSSAPI
1447 };
1448
1449 /* As a server, this could in theory accept any GSSAPI mech */
1450 static const struct gensec_security_ops gensec_gssapi_sasl_krb5_security_ops = {
1451         .name             = "gssapi_krb5_sasl",
1452         .sasl_name        = "GSSAPI",
1453         .client_start     = gensec_gssapi_sasl_client_start,
1454         .server_start     = gensec_gssapi_sasl_server_start,
1455         .update           = gensec_gssapi_update,
1456         .session_key      = gensec_gssapi_session_key,
1457         .session_info     = gensec_gssapi_session_info,
1458         .max_input_size   = gensec_gssapi_max_input_size,
1459         .max_wrapped_size = gensec_gssapi_max_wrapped_size,
1460         .wrap             = gensec_gssapi_wrap,
1461         .unwrap           = gensec_gssapi_unwrap,
1462         .have_feature     = gensec_gssapi_have_feature,
1463         .enabled          = true,
1464         .kerberos         = true,
1465         .priority         = GENSEC_GSSAPI
1466 };
1467
1468 _PUBLIC_ NTSTATUS gensec_gssapi_init(void)
1469 {
1470         NTSTATUS ret;
1471
1472         ret = gensec_register(&gensec_gssapi_spnego_security_ops);
1473         if (!NT_STATUS_IS_OK(ret)) {
1474                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1475                         gensec_gssapi_spnego_security_ops.name));
1476                 return ret;
1477         }
1478
1479         ret = gensec_register(&gensec_gssapi_krb5_security_ops);
1480         if (!NT_STATUS_IS_OK(ret)) {
1481                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1482                         gensec_gssapi_krb5_security_ops.name));
1483                 return ret;
1484         }
1485
1486         ret = gensec_register(&gensec_gssapi_sasl_krb5_security_ops);
1487         if (!NT_STATUS_IS_OK(ret)) {
1488                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
1489                         gensec_gssapi_sasl_krb5_security_ops.name));
1490                 return ret;
1491         }
1492
1493         return ret;
1494 }