source4/auth/gensec/gensec_gssapi.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Kerberos backend for GENSEC
   5
   6    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
   7    Copyright (C) Stefan Metzmacher <metze@samba.org> 2004-2005
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23 */
  24
  25 #include "includes.h"
  26 #include "system/kerberos.h"
  27 #include "auth/kerberos/kerberos.h"
  28 #include "librpc/gen_ndr/ndr_krb5pac.h"
  29 #include "auth/auth.h"
  30
  31 struct gensec_gssapi_state {
  32         gss_ctx_id_t gssapi_context;
  33         struct gss_channel_bindings_struct *input_chan_bindings;
  34         gss_name_t server_name;
  35         gss_name_t client_name;
  36         OM_uint32 want_flags, got_flags;
  37         const gss_OID_desc *gss_oid;
  38
  39         DATA_BLOB session_key;
  40         DATA_BLOB pac;
  41
  42         struct smb_krb5_context *smb_krb5_context;
  43         struct gssapi_creds_container *client_cred;
  44         struct gssapi_creds_container *server_cred;
  45
  46         gss_cred_id_t delegated_cred_handle;
  47 };
  48
  49 static char *gssapi_error_string(TALLOC_CTX *mem_ctx,
  50                                  OM_uint32 maj_stat, OM_uint32 min_stat)
  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         OM_uint32 msg_ctx = 0;
  56
  57         char *ret;
  58
  59         maj_error_message.value = NULL;
  60         min_error_message.value = NULL;
  61
  62         disp_maj_stat = gss_display_status(&disp_min_stat, maj_stat, GSS_C_GSS_CODE,
  63                            GSS_C_NULL_OID, &msg_ctx, &maj_error_message);
  64         disp_maj_stat = gss_display_status(&disp_min_stat, min_stat, GSS_C_MECH_CODE,
  65                            GSS_C_NULL_OID, &msg_ctx, &min_error_message);
  66         ret = talloc_asprintf(mem_ctx, "%s: %s", (char *)maj_error_message.value, (char *)min_error_message.value);
  67
  68         gss_release_buffer(&disp_min_stat, &maj_error_message);
  69         gss_release_buffer(&disp_min_stat, &min_error_message);
  70
  71         return ret;
  72 }
  73
  74
  75 static int gensec_gssapi_destory(void *ptr)
  76 {
  77         struct gensec_gssapi_state *gensec_gssapi_state = ptr;
  78         OM_uint32 maj_stat, min_stat;
  79
  80         if (gensec_gssapi_state->delegated_cred_handle != GSS_C_NO_CREDENTIAL) {
  81                 maj_stat = gss_release_cred(&min_stat,
  82                                             &gensec_gssapi_state->delegated_cred_handle);
  83         }
  84
  85         if (gensec_gssapi_state->gssapi_context != GSS_C_NO_CONTEXT) {
  86                 maj_stat = gss_delete_sec_context (&min_stat,
  87                                                    &gensec_gssapi_state->gssapi_context,
  88                                                    GSS_C_NO_BUFFER);
  89         }
  90
  91         if (gensec_gssapi_state->server_name != GSS_C_NO_NAME) {
  92                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->server_name);
  93         }
  94         if (gensec_gssapi_state->client_name != GSS_C_NO_NAME) {
  95                 maj_stat = gss_release_name(&min_stat, &gensec_gssapi_state->client_name);
  96         }
  97         return 0;
  98 }
  99
 100 static NTSTATUS gensec_gssapi_start(struct gensec_security *gensec_security)
 101 {
 102         struct gensec_gssapi_state *gensec_gssapi_state;
 103         krb5_error_code ret;
 104
 105         gensec_gssapi_state = talloc(gensec_security, struct gensec_gssapi_state);
 106         if (!gensec_gssapi_state) {
 107                 return NT_STATUS_NO_MEMORY;
 108         }
 109
 110         gensec_security->private_data = gensec_gssapi_state;
 111
 112         gensec_gssapi_state->gssapi_context = GSS_C_NO_CONTEXT;
 113         gensec_gssapi_state->server_name = GSS_C_NO_NAME;
 114         gensec_gssapi_state->client_name = GSS_C_NO_NAME;
 115
 116         /* TODO: Fill in channel bindings */
 117         gensec_gssapi_state->input_chan_bindings = GSS_C_NO_CHANNEL_BINDINGS;
 118
 119         gensec_gssapi_state->want_flags = 0;
 120         if (lp_parm_bool(-1, "gensec_gssapi", "mutual", True)) {
 121                 gensec_gssapi_state->want_flags |= GSS_C_MUTUAL_FLAG;
 122         }
 123         if (lp_parm_bool(-1, "gensec_gssapi", "delegation", True)) {
 124                 gensec_gssapi_state->want_flags |= GSS_C_DELEG_FLAG;
 125         }
 126
 127         gensec_gssapi_state->got_flags = 0;
 128
 129         gensec_gssapi_state->session_key = data_blob(NULL, 0);
 130         gensec_gssapi_state->pac = data_blob(NULL, 0);
 131
 132         gensec_gssapi_state->delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 133
 134         talloc_set_destructor(gensec_gssapi_state, gensec_gssapi_destory);
 135
 136         if (gensec_security->want_features & GENSEC_FEATURE_SIGN) {
 137                 gensec_gssapi_state->want_flags |= GSS_C_INTEG_FLAG;
 138         }
 139         if (gensec_security->want_features & GENSEC_FEATURE_SEAL) {
 140                 gensec_gssapi_state->want_flags |= GSS_C_CONF_FLAG;
 141         }
 142         if (gensec_security->want_features & GENSEC_FEATURE_DCE_STYLE) {
 143                 gensec_gssapi_state->want_flags |= GSS_C_DCE_STYLE;
 144         }
 145
 146         gensec_gssapi_state->gss_oid = gss_mech_krb5;
 147
 148         ret = smb_krb5_init_context(gensec_gssapi_state,
 149                                     &gensec_gssapi_state->smb_krb5_context);
 150         if (ret) {
 151                 DEBUG(1,("gensec_krb5_start: krb5_init_context failed (%s)\n",
 152                          error_message(ret)));
 153                 return NT_STATUS_INTERNAL_ERROR;
 154         }
 155         return NT_STATUS_OK;
 156 }
 157
 158 static NTSTATUS gensec_gssapi_server_start(struct gensec_security *gensec_security)
 159 {
 160         NTSTATUS nt_status;
 161         int ret;
 162         struct gensec_gssapi_state *gensec_gssapi_state;
 163         struct cli_credentials *machine_account;
 164         struct gssapi_creds_container *gcc;
 165
 166         nt_status = gensec_gssapi_start(gensec_security);
 167         if (!NT_STATUS_IS_OK(nt_status)) {
 168                 return nt_status;
 169         }
 170
 171         gensec_gssapi_state = gensec_security->private_data;
 172
 173         machine_account = gensec_get_credentials(gensec_security);
 174
 175         if (!machine_account) {
 176                 DEBUG(3, ("No machine account credentials specified\n"));
 177                 return NT_STATUS_INVALID_PARAMETER;
 178         } else {
 179                 ret = cli_credentials_get_server_gss_creds(machine_account, &gcc);
 180                 if (ret) {
 181                         DEBUG(1, ("Aquiring acceptor credentials failed: %s\n",
 182                                   error_message(ret)));
 183                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 184                 }
 185         }
 186
 187         gensec_gssapi_state->server_cred = gcc;
 188         return NT_STATUS_OK;
 189
 190 }
 191
 192 static NTSTATUS gensec_gssapi_client_start(struct gensec_security *gensec_security)
 193 {
 194         struct gensec_gssapi_state *gensec_gssapi_state;
 195         struct cli_credentials *creds = gensec_get_credentials(gensec_security);
 196         krb5_error_code ret;
 197         NTSTATUS nt_status;
 198         gss_buffer_desc name_token;
 199         gss_OID name_type;
 200         OM_uint32 maj_stat, min_stat;
 201         const char *hostname = gensec_get_target_hostname(gensec_security);
 202         const char *principal;
 203         struct gssapi_creds_container *gcc;
 204
 205         if (!hostname) {
 206                 DEBUG(1, ("Could not determine hostname for target computer, cannot use kerberos\n"));
 207                 return NT_STATUS_INVALID_PARAMETER;
 208         }
 209         if (is_ipaddress(hostname)) {
 210                 DEBUG(2, ("Cannot do GSSAPI to an IP address\n"));
 211                 return NT_STATUS_INVALID_PARAMETER;
 212         }
 213         if (strequal(hostname, "localhost")) {
 214                 DEBUG(2, ("GSSAPI to 'localhost' does not make sense\n"));
 215                 return NT_STATUS_INVALID_PARAMETER;
 216         }
 217
 218         nt_status = gensec_gssapi_start(gensec_security);
 219         if (!NT_STATUS_IS_OK(nt_status)) {
 220                 return nt_status;
 221         }
 222
 223         gensec_gssapi_state = gensec_security->private_data;
 224
 225         principal = gensec_get_target_principal(gensec_security);
 226         if (principal && lp_client_use_spnego_principal()) {
 227                 name_token.value  = discard_const_p(uint8_t, principal);
 228                 name_token.length = strlen(principal);
 229
 230                 name_type = GSS_C_NULL_OID;
 231         } else {
 232                 principal = talloc_asprintf(gensec_gssapi_state, "%s@%s",
 233                                             gensec_get_target_service(gensec_security),
 234                                             hostname);
 235
 236                 name_token.value  = discard_const_p(uint8_t, principal);
 237                 name_token.length = strlen(principal);
 238
 239                 name_type = GSS_C_NT_HOSTBASED_SERVICE;
 240         }
 241
 242         maj_stat = gss_import_name (&min_stat,
 243                                     &name_token,
 244                                     name_type,
 245                                     &gensec_gssapi_state->server_name);
 246         if (maj_stat) {
 247                 DEBUG(2, ("GSS Import name of %s failed: %s\n",
 248                           (char *)name_token.value,
 249                           gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 250                 return NT_STATUS_INVALID_PARAMETER;
 251         }
 252
 253         ret = cli_credentials_get_client_gss_creds(creds, &gcc);
 254         switch (ret) {
 255         case 0:
 256                 break;
 257         case KRB5_KDC_UNREACH:
 258                 DEBUG(3, ("Cannot reach a KDC we require\n"));
 259                 return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 260         default:
 261                 DEBUG(1, ("Aquiring initiator credentails failed\n"));
 262                 return NT_STATUS_UNSUCCESSFUL;
 263         }
 264
 265         gensec_gssapi_state->client_cred = gcc;
 266
 267         return NT_STATUS_OK;
 268 }
 269
 270
 271 /**
 272  * Check if the packet is one for this mechansim
 273  *
 274  * @param gensec_security GENSEC state
 275  * @param in The request, as a DATA_BLOB
 276  * @return Error, INVALID_PARAMETER if it's not a packet for us
 277  *                or NT_STATUS_OK if the packet is ok.
 278  */
 279
 280 static NTSTATUS gensec_gssapi_magic(struct gensec_security *gensec_security,
 281                                     const DATA_BLOB *in)
 282 {
 283         if (gensec_gssapi_check_oid(in, GENSEC_OID_KERBEROS5)) {
 284                 return NT_STATUS_OK;
 285         } else {
 286                 return NT_STATUS_INVALID_PARAMETER;
 287         }
 288 }
 289
 290
 291 /**
 292  * Next state function for the GSSAPI GENSEC mechanism
 293  *
 294  * @param gensec_gssapi_state GSSAPI State
 295  * @param out_mem_ctx The TALLOC_CTX for *out to be allocated on
 296  * @param in The request, as a DATA_BLOB
 297  * @param out The reply, as an talloc()ed DATA_BLOB, on *out_mem_ctx
 298  * @return Error, MORE_PROCESSING_REQUIRED if a reply is sent,
 299  *                or NT_STATUS_OK if the user is authenticated.
 300  */
 301
 302 static NTSTATUS gensec_gssapi_update(struct gensec_security *gensec_security,
 303                                    TALLOC_CTX *out_mem_ctx,
 304                                    const DATA_BLOB in, DATA_BLOB *out)
 305 {
 306         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 307         NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE;
 308         OM_uint32 maj_stat, min_stat;
 309         OM_uint32 min_stat2;
 310         gss_buffer_desc input_token, output_token;
 311         gss_OID gss_oid_p;
 312         input_token.length = in.length;
 313         input_token.value = in.data;
 314
 315         switch (gensec_security->gensec_role) {
 316         case GENSEC_CLIENT:
 317         {
 318                 maj_stat = gss_init_sec_context(&min_stat,
 319                                                 gensec_gssapi_state->client_cred->creds,
 320                                                 &gensec_gssapi_state->gssapi_context,
 321                                                 gensec_gssapi_state->server_name,
 322                                                 discard_const_p(gss_OID_desc, gensec_gssapi_state->gss_oid),
 323                                                 gensec_gssapi_state->want_flags,
 324                                                 0,
 325                                                 gensec_gssapi_state->input_chan_bindings,
 326                                                 &input_token,
 327                                                 NULL,
 328                                                 &output_token,
 329                                                 &gensec_gssapi_state->got_flags, /* ret flags */
 330                                                 NULL);
 331                 break;
 332         }
 333         case GENSEC_SERVER:
 334         {
 335                 maj_stat = gss_accept_sec_context(&min_stat,
 336                                                   &gensec_gssapi_state->gssapi_context,
 337                                                   gensec_gssapi_state->server_cred->creds,
 338                                                   &input_token,
 339                                                   gensec_gssapi_state->input_chan_bindings,
 340                                                   &gensec_gssapi_state->client_name,
 341                                                   &gss_oid_p,
 342                                                   &output_token,
 343                                                   &gensec_gssapi_state->got_flags,
 344                                                   NULL,
 345                                                   &gensec_gssapi_state->delegated_cred_handle);
 346                 gensec_gssapi_state->gss_oid = gss_oid_p;
 347                 break;
 348         }
 349         default:
 350                 return NT_STATUS_INVALID_PARAMETER;
 351
 352         }
 353
 354         if (maj_stat == GSS_S_COMPLETE) {
 355                 *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 356                 gss_release_buffer(&min_stat2, &output_token);
 357
 358                 if (gensec_gssapi_state->got_flags & GSS_C_DELEG_FLAG) {
 359                         DEBUG(5, ("gensec_gssapi: credentials were delegated\n"));
 360                 } else {
 361                         DEBUG(5, ("gensec_gssapi: NO credentials were delegated\n"));
 362                 }
 363
 364                 return NT_STATUS_OK;
 365         } else if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 366                 *out = data_blob_talloc(out_mem_ctx, output_token.value, output_token.length);
 367                 gss_release_buffer(&min_stat2, &output_token);
 368
 369                 return NT_STATUS_MORE_PROCESSING_REQUIRED;
 370         } else if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 371             && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 372                        gensec_gssapi_state->gss_oid->length) == 0)) {
 373                 switch (min_stat) {
 374                 case KRB5_KDC_UNREACH:
 375                         DEBUG(3, ("Cannot reach a KDC we require: %s\n",
 376                                   gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 377                         return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 378                 case KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN:
 379                         DEBUG(3, ("Server is not registered with our KDC: %s\n",
 380                                   gssapi_error_string(gensec_gssapi_state, maj_stat, min_stat)));
 381                         return NT_STATUS_INVALID_PARAMETER; /* Make SPNEGO ignore us, we can't go any further here */
 382                 case KRB5KRB_AP_ERR_MSG_TYPE:
 383                         /* garbage input, possibly from the auto-mech detection */
 384                         return NT_STATUS_INVALID_PARAMETER;
 385                 default:
 386                         DEBUG(1, ("GSS(krb5) Update failed: %s\n",
 387                                   gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 388                         return nt_status;
 389                 }
 390         } else {
 391                 DEBUG(1, ("GSS Update failed: %s\n",
 392                           gssapi_error_string(out_mem_ctx, maj_stat, min_stat)));
 393                 return nt_status;
 394         }
 395 }
 396
 397 static NTSTATUS gensec_gssapi_wrap(struct gensec_security *gensec_security,
 398                                    TALLOC_CTX *mem_ctx,
 399                                    const DATA_BLOB *in,
 400                                    DATA_BLOB *out)
 401 {
 402         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 403         OM_uint32 maj_stat, min_stat;
 404         gss_buffer_desc input_token, output_token;
 405         int conf_state;
 406         input_token.length = in->length;
 407         input_token.value = in->data;
 408
 409         maj_stat = gss_wrap(&min_stat,
 410                             gensec_gssapi_state->gssapi_context,
 411                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 412                             GSS_C_QOP_DEFAULT,
 413                             &input_token,
 414                             &conf_state,
 415                             &output_token);
 416         if (GSS_ERROR(maj_stat)) {
 417                 DEBUG(1, ("gensec_gssapi_wrap: GSS Wrap failed: %s\n",
 418                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 419                 return NT_STATUS_ACCESS_DENIED;
 420         }
 421
 422         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 423         gss_release_buffer(&min_stat, &output_token);
 424
 425         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 426             && !conf_state) {
 427                 return NT_STATUS_ACCESS_DENIED;
 428         }
 429         return NT_STATUS_OK;
 430 }
 431
 432 static NTSTATUS gensec_gssapi_unwrap(struct gensec_security *gensec_security,
 433                                      TALLOC_CTX *mem_ctx,
 434                                      const DATA_BLOB *in,
 435                                      DATA_BLOB *out)
 436 {
 437         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 438         OM_uint32 maj_stat, min_stat;
 439         gss_buffer_desc input_token, output_token;
 440         int conf_state;
 441         gss_qop_t qop_state;
 442         input_token.length = in->length;
 443         input_token.value = in->data;
 444
 445         maj_stat = gss_unwrap(&min_stat,
 446                               gensec_gssapi_state->gssapi_context,
 447                               &input_token,
 448                               &output_token,
 449                               &conf_state,
 450                               &qop_state);
 451         if (GSS_ERROR(maj_stat)) {
 452                 DEBUG(1, ("gensec_gssapi_unwrap: GSS UnWrap failed: %s\n",
 453                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 454                 return NT_STATUS_ACCESS_DENIED;
 455         }
 456
 457         *out = data_blob_talloc(mem_ctx, output_token.value, output_token.length);
 458         gss_release_buffer(&min_stat, &output_token);
 459
 460         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 461             && !conf_state) {
 462                 return NT_STATUS_ACCESS_DENIED;
 463         }
 464         return NT_STATUS_OK;
 465 }
 466
 467 static size_t gensec_gssapi_sig_size(struct gensec_security *gensec_security, size_t data_size)
 468 {
 469         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 470         OM_uint32 maj_stat, min_stat;
 471         OM_uint32 output_size;
 472         if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
 473             || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 474                        gensec_gssapi_state->gss_oid->length) != 0)) {
 475                 DEBUG(1, ("NO sig size available for this mech\n"));
 476                 return 0;
 477         }
 478
 479         maj_stat = gsskrb5_wrap_size(&min_stat,
 480                                      gensec_gssapi_state->gssapi_context,
 481                                      gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 482                                      GSS_C_QOP_DEFAULT,
 483                                      data_size,
 484                                      &output_size);
 485         if (GSS_ERROR(maj_stat)) {
 486                 TALLOC_CTX *mem_ctx = talloc_new(NULL);
 487                 DEBUG(1, ("gensec_gssapi_seal_packet: determinaing signature size with gss_wrap_size_limit failed: %s\n",
 488                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 489                 talloc_free(mem_ctx);
 490                 return 0;
 491         }
 492
 493         if (output_size < data_size) {
 494                 return 0;
 495         }
 496
 497         /* The difference between the max output and the max input must be the signature */
 498         return output_size - data_size;
 499 }
 500
 501 static NTSTATUS gensec_gssapi_seal_packet(struct gensec_security *gensec_security,
 502                                           TALLOC_CTX *mem_ctx,
 503                                           uint8_t *data, size_t length,
 504                                           const uint8_t *whole_pdu, size_t pdu_length,
 505                                           DATA_BLOB *sig)
 506 {
 507         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 508         OM_uint32 maj_stat, min_stat;
 509         gss_buffer_desc input_token, output_token;
 510         int conf_state;
 511         ssize_t sig_length;
 512
 513         input_token.length = length;
 514         input_token.value = data;
 515
 516         maj_stat = gss_wrap(&min_stat,
 517                             gensec_gssapi_state->gssapi_context,
 518                             gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL),
 519                             GSS_C_QOP_DEFAULT,
 520                             &input_token,
 521                             &conf_state,
 522                             &output_token);
 523         if (GSS_ERROR(maj_stat)) {
 524                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap failed: %s\n",
 525                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 526                 return NT_STATUS_ACCESS_DENIED;
 527         }
 528
 529         sig_length = gensec_gssapi_sig_size(gensec_security, length);
 530
 531         /* Caller must pad to right boundary */
 532         if (output_token.length != (length + sig_length)) {
 533                 DEBUG(1, ("gensec_gssapi_seal_packet: GSS Wrap length [%ld] does not match caller length [%ld] plus sig size [%ld] = [%ld]\n",
 534                           (long)output_token.length, (long)length, (long)sig_length, (long)(length + sig_length)));
 535                 return NT_STATUS_INTERNAL_ERROR;
 536         }
 537
 538         memcpy(data, ((uint8_t *)output_token.value) + sig_length, length);
 539         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 540
 541         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 542         dump_data_pw("gensec_gssapi_seal_packet: clear\n", data, length);
 543         dump_data_pw("gensec_gssapi_seal_packet: sealed\n", ((uint8_t *)output_token.value) + sig_length, output_token.length - sig_length);
 544
 545         gss_release_buffer(&min_stat, &output_token);
 546
 547         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 548             && !conf_state) {
 549                 return NT_STATUS_ACCESS_DENIED;
 550         }
 551         return NT_STATUS_OK;
 552 }
 553
 554 static NTSTATUS gensec_gssapi_unseal_packet(struct gensec_security *gensec_security,
 555                                             TALLOC_CTX *mem_ctx,
 556                                             uint8_t *data, size_t length,
 557                                             const uint8_t *whole_pdu, size_t pdu_length,
 558                                             const DATA_BLOB *sig)
 559 {
 560         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 561         OM_uint32 maj_stat, min_stat;
 562         gss_buffer_desc input_token, output_token;
 563         int conf_state;
 564         gss_qop_t qop_state;
 565         DATA_BLOB in;
 566
 567         dump_data_pw("gensec_gssapi_unseal_packet: sig\n", sig->data, sig->length);
 568
 569         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 570
 571         memcpy(in.data, sig->data, sig->length);
 572         memcpy(in.data + sig->length, data, length);
 573
 574         input_token.length = in.length;
 575         input_token.value = in.data;
 576
 577         maj_stat = gss_unwrap(&min_stat,
 578                               gensec_gssapi_state->gssapi_context,
 579                               &input_token,
 580                               &output_token,
 581                               &conf_state,
 582                               &qop_state);
 583         if (GSS_ERROR(maj_stat)) {
 584                 DEBUG(1, ("gensec_gssapi_unseal_packet: GSS UnWrap failed: %s\n",
 585                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 586                 return NT_STATUS_ACCESS_DENIED;
 587         }
 588
 589         if (output_token.length != length) {
 590                 return NT_STATUS_INTERNAL_ERROR;
 591         }
 592
 593         memcpy(data, output_token.value, length);
 594
 595         gss_release_buffer(&min_stat, &output_token);
 596
 597         if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)
 598             && !conf_state) {
 599                 return NT_STATUS_ACCESS_DENIED;
 600         }
 601         return NT_STATUS_OK;
 602 }
 603
 604 static NTSTATUS gensec_gssapi_sign_packet(struct gensec_security *gensec_security,
 605                                           TALLOC_CTX *mem_ctx,
 606                                           const uint8_t *data, size_t length,
 607                                           const uint8_t *whole_pdu, size_t pdu_length,
 608                                           DATA_BLOB *sig)
 609 {
 610         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 611         OM_uint32 maj_stat, min_stat;
 612         gss_buffer_desc input_token, output_token;
 613         int conf_state;
 614         ssize_t sig_length = 0;
 615
 616         input_token.length = length;
 617         input_token.value = discard_const_p(uint8_t *, data);
 618
 619         maj_stat = gss_wrap(&min_stat,
 620                             gensec_gssapi_state->gssapi_context,
 621                             0,
 622                             GSS_C_QOP_DEFAULT,
 623                             &input_token,
 624                             &conf_state,
 625                             &output_token);
 626         if (GSS_ERROR(maj_stat)) {
 627                 DEBUG(1, ("GSS Wrap failed: %s\n",
 628                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 629                 return NT_STATUS_ACCESS_DENIED;
 630         }
 631
 632         if (output_token.length < length) {
 633                 return NT_STATUS_INTERNAL_ERROR;
 634         }
 635
 636         sig_length = gensec_gssapi_sig_size(gensec_security, length);
 637
 638         /* Caller must pad to right boundary */
 639         if (output_token.length != (length + sig_length)) {
 640                 DEBUG(1, ("gensec_gssapi_sign_packet: GSS Wrap length [%ld] does not match caller length [%ld] plus sig size [%ld] = [%ld]\n",
 641                           (long)output_token.length, (long)length, (long)sig_length, (long)(length + sig_length)));
 642                 return NT_STATUS_INTERNAL_ERROR;
 643         }
 644
 645         *sig = data_blob_talloc(mem_ctx, (uint8_t *)output_token.value, sig_length);
 646
 647         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 648
 649         gss_release_buffer(&min_stat, &output_token);
 650
 651         return NT_STATUS_OK;
 652 }
 653
 654 static NTSTATUS gensec_gssapi_check_packet(struct gensec_security *gensec_security,
 655                                            TALLOC_CTX *mem_ctx,
 656                                            const uint8_t *data, size_t length,
 657                                            const uint8_t *whole_pdu, size_t pdu_length,
 658                                            const DATA_BLOB *sig)
 659 {
 660         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 661         OM_uint32 maj_stat, min_stat;
 662         gss_buffer_desc input_token, output_token;
 663         int conf_state;
 664         gss_qop_t qop_state;
 665         DATA_BLOB in;
 666
 667         dump_data_pw("gensec_gssapi_seal_packet: sig\n", sig->data, sig->length);
 668
 669         in = data_blob_talloc(mem_ctx, NULL, sig->length + length);
 670
 671         memcpy(in.data, sig->data, sig->length);
 672         memcpy(in.data + sig->length, data, length);
 673
 674         input_token.length = in.length;
 675         input_token.value = in.data;
 676
 677         maj_stat = gss_unwrap(&min_stat,
 678                               gensec_gssapi_state->gssapi_context,
 679                               &input_token,
 680                               &output_token,
 681                               &conf_state,
 682                               &qop_state);
 683         if (GSS_ERROR(maj_stat)) {
 684                 DEBUG(1, ("GSS UnWrap failed: %s\n",
 685                           gssapi_error_string(mem_ctx, maj_stat, min_stat)));
 686                 return NT_STATUS_ACCESS_DENIED;
 687         }
 688
 689         if (output_token.length != length) {
 690                 return NT_STATUS_INTERNAL_ERROR;
 691         }
 692
 693         gss_release_buffer(&min_stat, &output_token);
 694
 695         return NT_STATUS_OK;
 696 }
 697
 698 static BOOL gensec_gssapi_have_feature(struct gensec_security *gensec_security,
 699                                        uint32_t feature)
 700 {
 701         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 702         if (feature & GENSEC_FEATURE_SIGN) {
 703                 return gensec_gssapi_state->got_flags & GSS_C_INTEG_FLAG;
 704         }
 705         if (feature & GENSEC_FEATURE_SEAL) {
 706                 return gensec_gssapi_state->got_flags & GSS_C_CONF_FLAG;
 707         }
 708         if (feature & GENSEC_FEATURE_SESSION_KEY) {
 709                 if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 710                     && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements, gensec_gssapi_state->gss_oid->length) == 0)) {
 711                         return True;
 712                 }
 713         }
 714         if (feature & GENSEC_FEATURE_DCE_STYLE) {
 715                 return gensec_gssapi_state->got_flags & GSS_C_DCE_STYLE;
 716         }
 717         if (feature & GENSEC_FEATURE_ASYNC_REPLIES) {
 718                 return True;
 719         }
 720         return False;
 721 }
 722
 723 static NTSTATUS gensec_gssapi_session_key(struct gensec_security *gensec_security,
 724                                           DATA_BLOB *session_key)
 725 {
 726         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 727
 728         if (gensec_gssapi_state->session_key.data) {
 729                 *session_key = gensec_gssapi_state->session_key;
 730                 return NT_STATUS_OK;
 731         }
 732
 733         /* Ensure we only call this for GSSAPI/krb5, otherwise things could get very ugly */
 734         if ((gensec_gssapi_state->gss_oid->length == gss_mech_krb5->length)
 735             && (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 736                        gensec_gssapi_state->gss_oid->length) == 0)) {
 737                 OM_uint32 maj_stat, min_stat;
 738                 gss_buffer_desc skey;
 739
 740                 maj_stat = gsskrb5_get_initiator_subkey(&min_stat,
 741                                                         gensec_gssapi_state->gssapi_context,
 742                                                         &skey);
 743
 744                 if (maj_stat == 0) {
 745                         DEBUG(10, ("Got KRB5 session key of length %d\n",
 746                                    (int)skey.length));
 747                         gensec_gssapi_state->session_key = data_blob_talloc(gensec_gssapi_state,
 748                                                                             skey.value, skey.length);
 749                         *session_key = gensec_gssapi_state->session_key;
 750                         dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
 751
 752                         gss_release_buffer(&min_stat, &skey);
 753                         return NT_STATUS_OK;
 754                 }
 755                 return NT_STATUS_NO_USER_SESSION_KEY;
 756         }
 757
 758         DEBUG(1, ("NO session key for this mech\n"));
 759         return NT_STATUS_NO_USER_SESSION_KEY;
 760 }
 761
 762 static NTSTATUS gensec_gssapi_session_info(struct gensec_security *gensec_security,
 763                                          struct auth_session_info **_session_info)
 764 {
 765         NTSTATUS nt_status;
 766         TALLOC_CTX *mem_ctx;
 767         struct gensec_gssapi_state *gensec_gssapi_state = gensec_security->private_data;
 768         struct auth_serversupplied_info *server_info = NULL;
 769         struct auth_session_info *session_info = NULL;
 770         struct PAC_LOGON_INFO *logon_info;
 771         OM_uint32 maj_stat, min_stat;
 772         gss_buffer_desc name_token;
 773         gss_buffer_desc pac;
 774         krb5_keyblock *keyblock;
 775         time_t authtime;
 776         krb5_principal principal;
 777         char *principal_string;
 778         DATA_BLOB pac_blob;
 779
 780         if ((gensec_gssapi_state->gss_oid->length != gss_mech_krb5->length)
 781             || (memcmp(gensec_gssapi_state->gss_oid->elements, gss_mech_krb5->elements,
 782                        gensec_gssapi_state->gss_oid->length) != 0)) {
 783                 DEBUG(1, ("NO session info available for this mech\n"));
 784                 return NT_STATUS_INVALID_PARAMETER;
 785         }
 786
 787         mem_ctx = talloc_named(gensec_gssapi_state, 0, "gensec_gssapi_session_info context");
 788         NT_STATUS_HAVE_NO_MEMORY(mem_ctx);
 789
 790         maj_stat = gss_display_name (&min_stat,
 791                                      gensec_gssapi_state->client_name,
 792                                      &name_token,
 793                                      NULL);
 794         if (maj_stat) {
 795                 return NT_STATUS_FOOBAR;
 796         }
 797
 798         principal_string = talloc_strndup(mem_ctx, name_token.value, name_token.length);
 799
 800         gss_release_buffer(&min_stat, &name_token);
 801
 802         if (!principal_string) {
 803                 talloc_free(mem_ctx);
 804                 return NT_STATUS_NO_MEMORY;
 805         }
 806
 807         maj_stat = gss_krb5_copy_service_keyblock(&min_stat,
 808                                                   gensec_gssapi_state->gssapi_context,
 809                                                   &keyblock);
 810
 811         if (maj_stat == 0) {
 812                 maj_stat = gsskrb5_extract_authtime_from_sec_context(&min_stat,
 813                                                                      gensec_gssapi_state->gssapi_context,
 814                                                                      &authtime);
 815         }
 816
 817         if (maj_stat == 0) {
 818                 maj_stat = gsskrb5_extract_authz_data_from_sec_context(&min_stat,
 819                                                                        gensec_gssapi_state->gssapi_context,
 820                                                                        KRB5_AUTHDATA_WIN2K_PAC,
 821                                                                        &pac);
 822         }
 823
 824         if (maj_stat == 0) {
 825                 pac_blob = data_blob_talloc(mem_ctx, pac.value, pac.length);
 826                 gss_release_buffer(&min_stat, &pac);
 827         }
 828
 829         /* IF we have the PAC - otherwise we need to get this
 830          * data from elsewere - local ldb, or (TODO) lookup of some
 831          * kind...
 832          */
 833         if (maj_stat == 0) {
 834                 krb5_error_code ret;
 835
 836                 ret = krb5_parse_name(gensec_gssapi_state->smb_krb5_context->krb5_context,
 837                                       principal_string, &principal);
 838                 if (ret) {
 839                         talloc_free(mem_ctx);
 840                         return NT_STATUS_INVALID_PARAMETER;
 841                 }
 842
 843                 /* decode and verify the pac */
 844                 nt_status = kerberos_pac_logon_info(mem_ctx, &logon_info, pac_blob,
 845                                                     gensec_gssapi_state->smb_krb5_context->krb5_context,
 846                                                     NULL, keyblock, principal, authtime, NULL);
 847                 krb5_free_principal(gensec_gssapi_state->smb_krb5_context->krb5_context, principal);
 848
 849                 if (NT_STATUS_IS_OK(nt_status)) {
 850                         union netr_Validation validation;
 851                         validation.sam3 = &logon_info->info3;
 852                         nt_status = make_server_info_netlogon_validation(gensec_gssapi_state,
 853                                                                          NULL,
 854                                                                          3, &validation,
 855                                                                          &server_info);
 856                         if (!NT_STATUS_IS_OK(nt_status)) {
 857                                 talloc_free(mem_ctx);
 858                                 return nt_status;
 859                         }
 860                 } else {
 861                         maj_stat = 1;
 862                 }
 863         }
 864
 865         if (maj_stat) {
 866                 DEBUG(1, ("Unable to use PAC, resorting to local user lookup!\n"));
 867                 nt_status = sam_get_server_info_principal(mem_ctx, principal_string,
 868                                                           &server_info);
 869
 870                 if (!NT_STATUS_IS_OK(nt_status)) {
 871                         talloc_free(mem_ctx);
 872                         return nt_status;
 873                 }
 874         }
 875
 876         /* references the server_info into the session_info */
 877         nt_status = auth_generate_session_info(gensec_gssapi_state, server_info, &session_info);
 878         talloc_free(mem_ctx);
 879         talloc_free(server_info);
 880         NT_STATUS_NOT_OK_RETURN(nt_status);
 881
 882         nt_status = gensec_gssapi_session_key(gensec_security, &session_info->session_key);
 883         NT_STATUS_NOT_OK_RETURN(nt_status);
 884
 885         if (!(gensec_gssapi_state->got_flags & GSS_C_DELEG_FLAG)) {
 886                 DEBUG(10, ("gensec_gssapi: NO delegated credentials supplied by client\n"));
 887         } else {
 888                 krb5_error_code ret;
 889                 DEBUG(10, ("gensec_gssapi: delegated credentials supplied by client\n"));
 890                 session_info->credentials = cli_credentials_init(session_info);
 891                 if (!session_info->credentials) {
 892                         return NT_STATUS_NO_MEMORY;
 893                 }
 894
 895                 cli_credentials_set_conf(session_info->credentials);
 896
 897                 ret = cli_credentials_set_client_gss_creds(session_info->credentials,
 898                                                            gensec_gssapi_state->delegated_cred_handle,
 899                                                            CRED_SPECIFIED);
 900                 if (ret) {
 901                         return NT_STATUS_NO_MEMORY;
 902                 }
 903                 /* It has been taken from this place... */
 904                 gensec_gssapi_state->delegated_cred_handle = GSS_C_NO_CREDENTIAL;
 905         }
 906         *_session_info = session_info;
 907
 908         return NT_STATUS_OK;
 909 }
 910
 911 static const char *gensec_gssapi_krb5_oids[] = {
 912         GENSEC_OID_KERBEROS5,
 913         GENSEC_OID_KERBEROS5_OLD,
 914         NULL
 915 };
 916
 917 /* As a server, this could in theory accept any GSSAPI mech */
 918 static const struct gensec_security_ops gensec_gssapi_krb5_security_ops = {
 919         .name           = "gssapi_krb5",
 920         .sasl_name      = "GSSAPI",
 921         .auth_type      = DCERPC_AUTH_TYPE_KRB5,
 922         .oid            = gensec_gssapi_krb5_oids,
 923         .client_start   = gensec_gssapi_client_start,
 924         .server_start   = gensec_gssapi_server_start,
 925         .magic          = gensec_gssapi_magic,
 926         .update         = gensec_gssapi_update,
 927         .session_key    = gensec_gssapi_session_key,
 928         .session_info   = gensec_gssapi_session_info,
 929         .sig_size       = gensec_gssapi_sig_size,
 930         .sign_packet    = gensec_gssapi_sign_packet,
 931         .check_packet   = gensec_gssapi_check_packet,
 932         .seal_packet    = gensec_gssapi_seal_packet,
 933         .unseal_packet  = gensec_gssapi_unseal_packet,
 934         .wrap           = gensec_gssapi_wrap,
 935         .unwrap         = gensec_gssapi_unwrap,
 936         .have_feature   = gensec_gssapi_have_feature,
 937         .enabled        = True
 938 };
 939
 940 NTSTATUS gensec_gssapi_init(void)
 941 {
 942         NTSTATUS ret;
 943
 944         ret = gensec_register(&gensec_gssapi_krb5_security_ops);
 945         if (!NT_STATUS_IS_OK(ret)) {
 946                 DEBUG(0,("Failed to register '%s' gensec backend!\n",
 947                         gensec_gssapi_krb5_security_ops.name));
 948                 return ret;
 949         }
 950
 951         return ret;
 952 }