source4/rpc_server/backupkey/dcesrv_backupkey.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    endpoint server for the backupkey interface
   5
   6    Copyright (C) Matthieu Patou <mat@samba.org> 2010
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "rpc_server/dcerpc_server.h"
  24 #include "librpc/gen_ndr/ndr_backupkey.h"
  25 #include "dsdb/common/util.h"
  26 #include "dsdb/samdb/samdb.h"
  27 #include "lib/ldb/include/ldb_errors.h"
  28 #include "../lib/util/util_ldb.h"
  29 #include "param/param.h"
  30 #include "auth/session.h"
  31 #include "system/network.h"
  32 #include <com_err.h>
  33 #include <hx509.h>
  34 #include <hcrypto/rsa.h>
  35 #include <hcrypto/bn.h>
  36 #include <hcrypto/sha.h>
  37 #include <der.h>
  38 #include "../lib/tsocket/tsocket.h"
  39 #include "../libcli/security/security.h"
  40
  41 #define BACKUPKEY_MIN_VERSION 2
  42 #define BACKUPKEY_MAX_VERSION 3
  43
  44 static const unsigned rsa_with_var_num[] = { 1, 2, 840, 113549, 1, 1, 1 };
  45 /* Equivalent to asn1_oid_id_pkcs1_rsaEncryption*/
  46 static const AlgorithmIdentifier _hx509_signature_rsa_with_var_num = {
  47         { 7, discard_const_p(unsigned, rsa_with_var_num) }, NULL
  48 };
  49
  50 static NTSTATUS set_lsa_secret(TALLOC_CTX *mem_ctx,
  51                                struct ldb_context *ldb,
  52                                const char *name,
  53                                const DATA_BLOB *secret)
  54 {
  55         struct ldb_message *msg;
  56         struct ldb_result *res;
  57         struct ldb_dn *domain_dn;
  58         struct ldb_dn *system_dn;
  59         struct ldb_val val;
  60         int ret;
  61         char *name2;
  62         struct timeval now = timeval_current();
  63         NTTIME nt_now = timeval_to_nttime(&now);
  64         const char *attrs[] = {
  65                 NULL
  66         };
  67
  68         domain_dn = ldb_get_default_basedn(ldb);
  69         if (!domain_dn) {
  70                 return NT_STATUS_INTERNAL_ERROR;
  71         }
  72
  73         msg = ldb_msg_new(mem_ctx);
  74         if (msg == NULL) {
  75                 return NT_STATUS_NO_MEMORY;
  76         }
  77
  78         /*
  79          * This function is a lot like dcesrv_lsa_CreateSecret
  80          * in the rpc_server/lsa directory
  81          * The reason why we duplicate the effort here is that:
  82          * * we want to keep the former function static
  83          * * we want to avoid the burden of doing LSA calls
  84          *   when we can just manipulate the secrets directly
  85          * * taillor the function to the particular needs of backup protocol
  86          */
  87
  88         system_dn = samdb_search_dn(ldb, msg, domain_dn, "(&(objectClass=container)(cn=System))");
  89         if (system_dn == NULL) {
  90                 talloc_free(msg);
  91                 return NT_STATUS_NO_MEMORY;
  92         }
  93
  94         name2 = talloc_asprintf(msg, "%s Secret", name);
  95         if (name2 == NULL) {
  96                 talloc_free(msg);
  97                 return NT_STATUS_NO_MEMORY;
  98         }
  99
 100         ret = ldb_search(ldb, mem_ctx, &res, system_dn, LDB_SCOPE_SUBTREE, attrs,
 101                            "(&(cn=%s)(objectclass=secret))",
 102                            ldb_binary_encode_string(mem_ctx, name2));
 103
 104         if (ret != LDB_SUCCESS ||  res->count != 0 ) {
 105                 DEBUG(2, ("Secret %s already exists !\n", name2));
 106                 talloc_free(msg);
 107                 return NT_STATUS_OBJECT_NAME_COLLISION;
 108         }
 109
 110         /*
 111          * We don't care about previous value as we are
 112          * here only if the key didn't exists before
 113          */
 114
 115         msg->dn = ldb_dn_copy(mem_ctx, system_dn);
 116         if (msg->dn == NULL) {
 117                 talloc_free(msg);
 118                 return NT_STATUS_NO_MEMORY;
 119         }
 120         if (!ldb_dn_add_child_fmt(msg->dn, "cn=%s", name2)) {
 121                 talloc_free(msg);
 122                 return NT_STATUS_NO_MEMORY;
 123         }
 124
 125         ret = ldb_msg_add_string(msg, "cn", name2);
 126         if (ret != LDB_SUCCESS) {
 127                 talloc_free(msg);
 128                 return NT_STATUS_NO_MEMORY;
 129         }
 130         ret = ldb_msg_add_string(msg, "objectClass", "secret");
 131         if (ret != LDB_SUCCESS) {
 132                 talloc_free(msg);
 133                 return NT_STATUS_NO_MEMORY;
 134         }
 135         ret = samdb_msg_add_uint64(ldb, mem_ctx, msg, "priorSetTime", nt_now);
 136         if (ret != LDB_SUCCESS) {
 137                 talloc_free(msg);
 138                 return NT_STATUS_NO_MEMORY;
 139         }
 140         val.data = secret->data;
 141         val.length = secret->length;
 142         ret = ldb_msg_add_value(msg, "currentValue", &val, NULL);
 143         if (ret != LDB_SUCCESS) {
 144                 talloc_free(msg);
 145                 return NT_STATUS_NO_MEMORY;
 146         }
 147         ret = samdb_msg_add_uint64(ldb, mem_ctx, msg, "lastSetTime", nt_now);
 148         if (ret != LDB_SUCCESS) {
 149                 talloc_free(msg);
 150                 return NT_STATUS_NO_MEMORY;
 151         }
 152
 153         /*
 154          * create the secret with DSDB_MODIFY_RELAX
 155          * otherwise dsdb/samdb/ldb_modules/objectclass.c forbid
 156          * the create of LSA secret object
 157          */
 158         ret = dsdb_add(ldb, msg, DSDB_MODIFY_RELAX);
 159         if (ret != LDB_SUCCESS) {
 160                 DEBUG(2,("Failed to create secret record %s: %s\n",
 161                         ldb_dn_get_linearized(msg->dn),
 162                         ldb_errstring(ldb)));
 163                 talloc_free(msg);
 164                 return NT_STATUS_ACCESS_DENIED;
 165         }
 166
 167         talloc_free(msg);
 168         return NT_STATUS_OK;
 169 }
 170
 171 /* This function is pretty much like dcesrv_lsa_QuerySecret */
 172 static NTSTATUS get_lsa_secret(TALLOC_CTX *mem_ctx,
 173                                struct ldb_context *ldb,
 174                                const char *name,
 175                                DATA_BLOB *secret)
 176 {
 177         TALLOC_CTX *tmp_mem;
 178         struct ldb_result *res;
 179         struct ldb_dn *domain_dn;
 180         struct ldb_dn *system_dn;
 181         const struct ldb_val *val;
 182         uint8_t *data;
 183         const char *attrs[] = {
 184                 "currentValue",
 185                 NULL
 186         };
 187         int ret;
 188
 189         secret->data = NULL;
 190         secret->length = 0;
 191
 192         domain_dn = ldb_get_default_basedn(ldb);
 193         if (!domain_dn) {
 194                 return NT_STATUS_INTERNAL_ERROR;
 195         }
 196
 197         tmp_mem = talloc_new(mem_ctx);
 198         if (tmp_mem == NULL) {
 199                 return NT_STATUS_NO_MEMORY;
 200         }
 201
 202         system_dn = samdb_search_dn(ldb, tmp_mem, domain_dn, "(&(objectClass=container)(cn=System))");
 203         if (system_dn == NULL) {
 204                 talloc_free(tmp_mem);
 205                 return NT_STATUS_NO_MEMORY;
 206         }
 207
 208         ret = ldb_search(ldb, mem_ctx, &res, system_dn, LDB_SCOPE_SUBTREE, attrs,
 209                            "(&(cn=%s Secret)(objectclass=secret))",
 210                            ldb_binary_encode_string(tmp_mem, name));
 211
 212         if (ret != LDB_SUCCESS || res->count == 0) {
 213                 talloc_free(tmp_mem);
 214                 /*
 215                  * Important NOT to use NT_STATUS_OBJECT_NAME_NOT_FOUND
 216                  * as this return value is used to detect the case
 217                  * when we have the secret but without the currentValue
 218                  * (case RODC)
 219                  */
 220                 return NT_STATUS_RESOURCE_NAME_NOT_FOUND;
 221         }
 222
 223         if (res->count > 1) {
 224                 DEBUG(2, ("Secret %s collision\n", name));
 225                 talloc_free(tmp_mem);
 226                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 227         }
 228
 229         val = ldb_msg_find_ldb_val(res->msgs[0], "currentValue");
 230         if (val == NULL) {
 231                 /*
 232                  * The secret object is here but we don't have the secret value
 233                  * The most common case is a RODC
 234                  */
 235                 talloc_free(tmp_mem);
 236                 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
 237         }
 238
 239         data = val->data;
 240         secret->data = talloc_move(mem_ctx, &data);
 241         secret->length = val->length;
 242
 243         talloc_free(tmp_mem);
 244         return NT_STATUS_OK;
 245 }
 246
 247 static DATA_BLOB *reverse_and_get_blob(TALLOC_CTX *mem_ctx, BIGNUM *bn)
 248 {
 249         DATA_BLOB blob;
 250         DATA_BLOB *rev = talloc(mem_ctx, DATA_BLOB);
 251         uint32_t i;
 252
 253         blob.length = BN_num_bytes(bn);
 254         blob.data = talloc_array(mem_ctx, uint8_t, blob.length);
 255
 256         if (blob.data == NULL) {
 257                 return NULL;
 258         }
 259
 260         BN_bn2bin(bn, blob.data);
 261
 262         rev->data = talloc_array(mem_ctx, uint8_t, blob.length);
 263         if (rev->data == NULL) {
 264                 return NULL;
 265         }
 266
 267         for(i=0; i < blob.length; i++) {
 268                 rev->data[i] = blob.data[blob.length - i -1];
 269         }
 270         rev->length = blob.length;
 271         talloc_free(blob.data);
 272         return rev;
 273 }
 274
 275 static BIGNUM *reverse_and_get_bignum(TALLOC_CTX *mem_ctx, DATA_BLOB *blob)
 276 {
 277         BIGNUM *ret;
 278         DATA_BLOB rev;
 279         uint32_t i;
 280
 281         rev.data = talloc_array(mem_ctx, uint8_t, blob->length);
 282         if (rev.data == NULL) {
 283                 return NULL;
 284         }
 285
 286         for(i=0; i < blob->length; i++) {
 287                 rev.data[i] = blob->data[blob->length - i -1];
 288         }
 289         rev.length = blob->length;
 290
 291         ret = BN_bin2bn(rev.data, rev.length, NULL);
 292         talloc_free(rev.data);
 293
 294         return ret;
 295 }
 296
 297 static NTSTATUS get_pk_from_raw_keypair_params(TALLOC_CTX *ctx,
 298                                 struct bkrp_exported_RSA_key_pair *keypair,
 299                                 hx509_private_key *pk)
 300 {
 301         hx509_context hctx;
 302         RSA *rsa;
 303         struct hx509_private_key_ops *ops;
 304
 305         hx509_context_init(&hctx);
 306         ops = hx509_find_private_alg(&_hx509_signature_rsa_with_var_num.algorithm);
 307         if (ops == NULL) {
 308                 DEBUG(2, ("Not supported algorithm\n"));
 309                 return NT_STATUS_INTERNAL_ERROR;
 310         }
 311
 312         if (hx509_private_key_init(pk, ops, NULL) != 0) {
 313                 hx509_context_free(&hctx);
 314                 return NT_STATUS_NO_MEMORY;
 315         }
 316
 317         rsa = RSA_new();
 318         if (rsa ==NULL) {
 319                 hx509_context_free(&hctx);
 320                 return NT_STATUS_INVALID_PARAMETER;
 321         }
 322
 323         rsa->n = reverse_and_get_bignum(ctx, &(keypair->modulus));
 324         if (rsa->n == NULL) {
 325                 RSA_free(rsa);
 326                 hx509_context_free(&hctx);
 327                 return NT_STATUS_INVALID_PARAMETER;
 328         }
 329         rsa->d = reverse_and_get_bignum(ctx, &(keypair->private_exponent));
 330         if (rsa->d == NULL) {
 331                 RSA_free(rsa);
 332                 hx509_context_free(&hctx);
 333                 return NT_STATUS_INVALID_PARAMETER;
 334         }
 335         rsa->p = reverse_and_get_bignum(ctx, &(keypair->prime1));
 336         if (rsa->p == NULL) {
 337                 RSA_free(rsa);
 338                 hx509_context_free(&hctx);
 339                 return NT_STATUS_INVALID_PARAMETER;
 340         }
 341         rsa->q = reverse_and_get_bignum(ctx, &(keypair->prime2));
 342         if (rsa->q == NULL) {
 343                 RSA_free(rsa);
 344                 hx509_context_free(&hctx);
 345                 return NT_STATUS_INVALID_PARAMETER;
 346         }
 347         rsa->dmp1 = reverse_and_get_bignum(ctx, &(keypair->exponent1));
 348         if (rsa->dmp1 == NULL) {
 349                 RSA_free(rsa);
 350                 hx509_context_free(&hctx);
 351                 return NT_STATUS_INVALID_PARAMETER;
 352         }
 353         rsa->dmq1 = reverse_and_get_bignum(ctx, &(keypair->exponent2));
 354         if (rsa->dmq1 == NULL) {
 355                 RSA_free(rsa);
 356                 hx509_context_free(&hctx);
 357                 return NT_STATUS_INVALID_PARAMETER;
 358         }
 359         rsa->iqmp = reverse_and_get_bignum(ctx, &(keypair->coefficient));
 360         if (rsa->iqmp == NULL) {
 361                 RSA_free(rsa);
 362                 hx509_context_free(&hctx);
 363                 return NT_STATUS_INVALID_PARAMETER;
 364         }
 365         rsa->e = reverse_and_get_bignum(ctx, &(keypair->public_exponent));
 366         if (rsa->e == NULL) {
 367                 RSA_free(rsa);
 368                 hx509_context_free(&hctx);
 369                 return NT_STATUS_INVALID_PARAMETER;
 370         }
 371
 372         hx509_private_key_assign_rsa(*pk, rsa);
 373
 374         hx509_context_free(&hctx);
 375         return NT_STATUS_OK;
 376 }
 377
 378 static WERROR get_and_verify_access_check(TALLOC_CTX *sub_ctx,
 379                                           uint32_t version,
 380                                           uint8_t *key_and_iv,
 381                                           uint8_t *access_check,
 382                                           uint32_t access_check_len,
 383                                           struct dom_sid **access_sid)
 384 {
 385         heim_octet_string iv;
 386         heim_octet_string access_check_os;
 387         hx509_crypto crypto;
 388
 389         DATA_BLOB blob_us;
 390         uint32_t key_len;
 391         uint32_t iv_len;
 392         int res;
 393         enum ndr_err_code ndr_err;
 394         hx509_context hctx;
 395
 396         /* This one should not be freed */
 397         const AlgorithmIdentifier *alg;
 398
 399         *access_sid = NULL;
 400         switch (version) {
 401         case 2:
 402                 key_len = 24;
 403                 iv_len = 8;
 404                 alg = hx509_crypto_des_rsdi_ede3_cbc();
 405                 break;
 406
 407         case 3:
 408                 key_len = 32;
 409                 iv_len = 16;
 410                 alg =hx509_crypto_aes256_cbc();
 411                 break;
 412
 413         default:
 414                 return WERR_INVALID_DATA;
 415         }
 416
 417         hx509_context_init(&hctx);
 418         res = hx509_crypto_init(hctx, NULL,
 419                                 &(alg->algorithm),
 420                                 &crypto);
 421         hx509_context_free(&hctx);
 422
 423         if (res != 0) {
 424                 return WERR_INVALID_DATA;
 425         }
 426
 427         res = hx509_crypto_set_key_data(crypto, key_and_iv, key_len);
 428
 429         iv.data = talloc_memdup(sub_ctx, key_len + key_and_iv, iv_len);
 430         iv.length = iv_len;
 431
 432         if (res != 0) {
 433                 hx509_crypto_destroy(crypto);
 434                 return WERR_INVALID_DATA;
 435         }
 436
 437         hx509_crypto_set_padding(crypto, HX509_CRYPTO_PADDING_NONE);
 438         res = hx509_crypto_decrypt(crypto,
 439                 access_check,
 440                 access_check_len,
 441                 &iv,
 442                 &access_check_os);
 443
 444         if (res != 0) {
 445                 hx509_crypto_destroy(crypto);
 446                 return WERR_INVALID_DATA;
 447         }
 448
 449         blob_us.data = access_check_os.data;
 450         blob_us.length = access_check_os.length;
 451
 452         hx509_crypto_destroy(crypto);
 453
 454         if (version == 2) {
 455                 uint32_t hash_size = 20;
 456                 uint8_t hash[hash_size];
 457                 struct sha sctx;
 458                 struct bkrp_access_check_v2 uncrypted_accesscheckv2;
 459
 460                 ndr_err = ndr_pull_struct_blob(&blob_us, sub_ctx, &uncrypted_accesscheckv2,
 461                                         (ndr_pull_flags_fn_t)ndr_pull_bkrp_access_check_v2);
 462                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 463                         /* Unable to unmarshall */
 464                         der_free_octet_string(&access_check_os);
 465                         return WERR_INVALID_DATA;
 466                 }
 467                 if (uncrypted_accesscheckv2.magic != 0x1) {
 468                         /* wrong magic */
 469                         der_free_octet_string(&access_check_os);
 470                         return WERR_INVALID_DATA;
 471                 }
 472
 473                 SHA1_Init(&sctx);
 474                 SHA1_Update(&sctx, blob_us.data, blob_us.length - hash_size);
 475                 SHA1_Final(hash, &sctx);
 476                 der_free_octet_string(&access_check_os);
 477                 /*
 478                  * We free it after the sha1 calculation because blob.data
 479                  * point to the same area
 480                  */
 481
 482                 if (memcmp(hash, uncrypted_accesscheckv2.hash, hash_size) != 0) {
 483                         DEBUG(2, ("Wrong hash value in the access check in backup key remote protocol\n"));
 484                         return WERR_INVALID_DATA;
 485                 }
 486                 *access_sid = dom_sid_dup(sub_ctx, &(uncrypted_accesscheckv2.sid));
 487                 if (*access_sid == NULL) {
 488                         return WERR_NOMEM;
 489                 }
 490                 return WERR_OK;
 491         }
 492
 493         if (version == 3) {
 494                 uint32_t hash_size = 64;
 495                 uint8_t hash[hash_size];
 496                 struct hc_sha512state sctx;
 497                 struct bkrp_access_check_v3 uncrypted_accesscheckv3;
 498
 499                 ndr_err = ndr_pull_struct_blob(&blob_us, sub_ctx, &uncrypted_accesscheckv3,
 500                                         (ndr_pull_flags_fn_t)ndr_pull_bkrp_access_check_v3);
 501                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 502                         /* Unable to unmarshall */
 503                         der_free_octet_string(&access_check_os);
 504                         return WERR_INVALID_DATA;
 505                 }
 506                 if (uncrypted_accesscheckv3.magic != 0x1) {
 507                         /* wrong magic */
 508                         der_free_octet_string(&access_check_os);
 509                         return WERR_INVALID_DATA;
 510                 }
 511
 512                 SHA512_Init(&sctx);
 513                 SHA512_Update(&sctx, blob_us.data, blob_us.length - hash_size);
 514                 SHA512_Final(hash, &sctx);
 515                 der_free_octet_string(&access_check_os);
 516                 /*
 517                  * We free it after the sha1 calculation because blob.data
 518                  * point to the same area
 519                  */
 520
 521                 if (memcmp(hash, uncrypted_accesscheckv3.hash, hash_size) != 0) {
 522                         DEBUG(2, ("Wrong hash value in the access check in backup key remote protocol\n"));
 523                         return WERR_INVALID_DATA;
 524                 }
 525                 *access_sid = dom_sid_dup(sub_ctx, &(uncrypted_accesscheckv3.sid));
 526                 if (*access_sid == NULL) {
 527                         return WERR_NOMEM;
 528                 }
 529                 return WERR_OK;
 530         }
 531
 532         /* Never reached normally as we filtered at the switch / case level */
 533         return WERR_INVALID_DATA;
 534 }
 535
 536 static WERROR bkrp_do_uncrypt_client_wrap_key(struct dcesrv_call_state *dce_call,
 537                                               TALLOC_CTX *mem_ctx,
 538                                               struct bkrp_BackupKey *r,
 539                                               struct ldb_context *ldb_ctx)
 540 {
 541         struct bkrp_client_side_wrapped uncrypt_request;
 542         DATA_BLOB blob;
 543         enum ndr_err_code ndr_err;
 544         char *guid_string;
 545         char *cert_secret_name;
 546         DATA_BLOB secret;
 547         DATA_BLOB *uncrypted;
 548         NTSTATUS status;
 549
 550         blob.data = r->in.data_in;
 551         blob.length = r->in.data_in_len;
 552
 553         if (r->in.data_in_len == 0 || r->in.data_in == NULL) {
 554                 return WERR_INVALID_PARAM;
 555         }
 556
 557         ndr_err = ndr_pull_struct_blob(&blob, mem_ctx, &uncrypt_request,
 558                                        (ndr_pull_flags_fn_t)ndr_pull_bkrp_client_side_wrapped);
 559         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 560                 return WERR_INVALID_PARAM;
 561         }
 562
 563         if (uncrypt_request.version < BACKUPKEY_MIN_VERSION) {
 564                 return WERR_INVALID_PARAMETER;
 565         }
 566
 567         if (uncrypt_request.version > BACKUPKEY_MAX_VERSION) {
 568                 return WERR_INVALID_PARAMETER;
 569         }
 570
 571         guid_string = GUID_string(mem_ctx, &uncrypt_request.guid);
 572         if (guid_string == NULL) {
 573                 return WERR_NOMEM;
 574         }
 575
 576         cert_secret_name = talloc_asprintf(mem_ctx,
 577                                            "BCKUPKEY_%s",
 578                                            guid_string);
 579         if (cert_secret_name == NULL) {
 580                 return WERR_NOMEM;
 581         }
 582
 583         status = get_lsa_secret(mem_ctx,
 584                                 ldb_ctx,
 585                                 cert_secret_name,
 586                                 &secret);
 587         if (!NT_STATUS_IS_OK(status)) {
 588                 DEBUG(10, ("Error while fetching secret %s\n", cert_secret_name));
 589                 if (NT_STATUS_EQUAL(status,NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
 590                         /* we do not have the real secret attribute */
 591                         return WERR_INVALID_PARAMETER;
 592                 } else {
 593                         return WERR_FILE_NOT_FOUND;
 594                 }
 595         }
 596
 597         if (secret.length != 0) {
 598                 hx509_context hctx;
 599                 struct bkrp_exported_RSA_key_pair keypair;
 600                 hx509_private_key pk;
 601                 uint32_t i, res;
 602                 struct dom_sid *access_sid = NULL;
 603                 heim_octet_string reversed_secret;
 604                 heim_octet_string uncrypted_secret;
 605                 AlgorithmIdentifier alg;
 606                 struct dom_sid *caller_sid;
 607                 DATA_BLOB blob_us;
 608                 WERROR werr;
 609
 610                 ndr_err = ndr_pull_struct_blob(&secret, mem_ctx, &keypair, (ndr_pull_flags_fn_t)ndr_pull_bkrp_exported_RSA_key_pair);
 611                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 612                         DEBUG(2, ("Unable to parse the ndr encoded cert in key %s\n", cert_secret_name));
 613                         return WERR_FILE_NOT_FOUND;
 614                 }
 615
 616                 status = get_pk_from_raw_keypair_params(mem_ctx, &keypair, &pk);
 617                 if (!NT_STATUS_IS_OK(status)) {
 618                         return WERR_INTERNAL_ERROR;
 619                 }
 620
 621                 reversed_secret.data = talloc_array(mem_ctx, uint8_t,
 622                                                     uncrypt_request.encrypted_secret_len);
 623                 if (reversed_secret.data == NULL) {
 624                         hx509_private_key_free(&pk);
 625                         return WERR_NOMEM;
 626                 }
 627
 628                 /* The secret has to be reversed ... */
 629                 for(i=0; i< uncrypt_request.encrypted_secret_len; i++) {
 630                         uint8_t *reversed = (uint8_t *)reversed_secret.data;
 631                         uint8_t *uncrypt = uncrypt_request.encrypted_secret;
 632                         reversed[i] = uncrypt[uncrypt_request.encrypted_secret_len - 1 - i];
 633                 }
 634                 reversed_secret.length = uncrypt_request.encrypted_secret_len;
 635
 636                 /*
 637                  * Let's try to decrypt the secret now that
 638                  * we have the private key ...
 639                  */
 640                 hx509_context_init(&hctx);
 641                 res = hx509_private_key_private_decrypt(hctx, &reversed_secret,
 642                                                          &alg.algorithm, pk,
 643                                                          &uncrypted_secret);
 644                 hx509_context_free(&hctx);
 645                 hx509_private_key_free(&pk);
 646                 if (res != 0) {
 647                         /* We are not able to decrypt the secret, looks like something is wrong */
 648                         return WERR_INVALID_DATA;
 649                 }
 650                 blob_us.data = uncrypted_secret.data;
 651                 blob_us.length = uncrypted_secret.length;
 652
 653                 if (uncrypt_request.version == 2) {
 654                         struct bkrp_encrypted_secret_v2 uncrypted_secretv2;
 655
 656                         ndr_err = ndr_pull_struct_blob(&blob_us, mem_ctx, &uncrypted_secretv2,
 657                                         (ndr_pull_flags_fn_t)ndr_pull_bkrp_encrypted_secret_v2);
 658                         der_free_octet_string(&uncrypted_secret);
 659                         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 660                                 /* Unable to unmarshall */
 661                                 return WERR_INVALID_DATA;
 662                         }
 663                         if (uncrypted_secretv2.magic != 0x20) {
 664                                 /* wrong magic */
 665                                 return WERR_INVALID_DATA;
 666                         }
 667
 668                         werr = get_and_verify_access_check(mem_ctx, 2,
 669                                                            uncrypted_secretv2.payload_key,
 670                                                            uncrypt_request.access_check,
 671                                                            uncrypt_request.access_check_len,
 672                                                            &access_sid);
 673                         if (!W_ERROR_IS_OK(werr)) {
 674                                 return werr;
 675                         }
 676                         uncrypted = talloc(mem_ctx, DATA_BLOB);
 677                         if (uncrypted == NULL) {
 678                                 return WERR_INVALID_DATA;
 679                         }
 680
 681                         uncrypted->data = uncrypted_secretv2.secret;
 682                         uncrypted->length = uncrypted_secretv2.secret_len;
 683                 }
 684                 if (uncrypt_request.version == 3) {
 685                         struct bkrp_encrypted_secret_v3 uncrypted_secretv3;
 686
 687                         ndr_err = ndr_pull_struct_blob(&blob_us, mem_ctx, &uncrypted_secretv3,
 688                                         (ndr_pull_flags_fn_t)ndr_pull_bkrp_encrypted_secret_v3);
 689
 690                         der_free_octet_string(&uncrypted_secret);
 691                         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 692                                 /* Unable to unmarshall */
 693                                 return WERR_INVALID_DATA;
 694                         }
 695
 696                         if (uncrypted_secretv3.magic1 != 0x30  ||
 697                             uncrypted_secretv3.magic2 != 0x6610 ||
 698                             uncrypted_secretv3.magic3 != 0x800e) {
 699                                 /* wrong magic */
 700                                 return WERR_INVALID_DATA;
 701                         }
 702
 703                         werr = get_and_verify_access_check(mem_ctx, 3,
 704                                                            uncrypted_secretv3.payload_key,
 705                                                            uncrypt_request.access_check,
 706                                                            uncrypt_request.access_check_len,
 707                                                            &access_sid);
 708                         if (!W_ERROR_IS_OK(werr)) {
 709                                 return werr;
 710                         }
 711
 712                         uncrypted = talloc(mem_ctx, DATA_BLOB);
 713                         if (uncrypted == NULL) {
 714                                 return WERR_INVALID_DATA;
 715                         }
 716
 717                         uncrypted->data = uncrypted_secretv3.secret;
 718                         uncrypted->length = uncrypted_secretv3.secret_len;
 719                 }
 720
 721                 caller_sid = &dce_call->conn->auth_state.session_info->security_token->sids[PRIMARY_USER_SID_INDEX];
 722
 723                 if (!dom_sid_equal(caller_sid, access_sid)) {
 724                         talloc_free(uncrypted);
 725                         return WERR_INVALID_ACCESS;
 726                 }
 727
 728                 /*
 729                  * Yeah if we are here all looks pretty good:
 730                  * - hash is ok
 731                  * - user sid is the same as the one in access check
 732                  * - we were able to decrypt the whole stuff
 733                  */
 734         }
 735
 736         if (uncrypted->data == NULL) {
 737                 return WERR_INVALID_DATA;
 738         }
 739
 740         /* There is a magic value a the beginning of the data
 741          * we can use an adhoc structure but as the
 742          * parent structure is just an array of bytes it a lot of work
 743          * work just prepending 4 bytes
 744          */
 745         *(r->out.data_out) = talloc_zero_array(mem_ctx, uint8_t, uncrypted->length + 4);
 746         W_ERROR_HAVE_NO_MEMORY(*(r->out.data_out));
 747         memcpy(4+*(r->out.data_out), uncrypted->data, uncrypted->length);
 748         *(r->out.data_out_len) = uncrypted->length + 4;
 749
 750         return WERR_OK;
 751 }
 752
 753 static WERROR create_heimdal_rsa_key(TALLOC_CTX *ctx, hx509_context *hctx,
 754                                      hx509_private_key *pk, RSA **_rsa)
 755 {
 756         BIGNUM *pub_expo;
 757         RSA *rsa;
 758         int ret;
 759         uint8_t *p0, *p;
 760         size_t len;
 761         int bits = 2048;
 762
 763         *_rsa = NULL;
 764
 765         pub_expo = BN_new();
 766         if(pub_expo == NULL) {
 767                 return WERR_INTERNAL_ERROR;
 768         }
 769
 770         /* set the public expo to 65537 like everyone */
 771         BN_set_word(pub_expo, 0x10001);
 772
 773         rsa = RSA_new();
 774         if(rsa == NULL) {
 775                 BN_free(pub_expo);
 776                 return WERR_INTERNAL_ERROR;
 777         }
 778
 779         ret = RSA_generate_key_ex(rsa, bits, pub_expo, NULL);
 780         if(ret != 1) {
 781                 RSA_free(rsa);
 782                 BN_free(pub_expo);
 783                 return WERR_INTERNAL_ERROR;
 784         }
 785         BN_free(pub_expo);
 786
 787         len = i2d_RSAPrivateKey(rsa, NULL);
 788         if (len < 1) {
 789                 RSA_free(rsa);
 790                 return WERR_INTERNAL_ERROR;
 791         }
 792
 793         p0 = p = talloc_array(ctx, uint8_t, len);
 794         if (p == NULL) {
 795                 RSA_free(rsa);
 796                 return WERR_INTERNAL_ERROR;
 797         }
 798
 799         len = i2d_RSAPrivateKey(rsa, &p);
 800         if (len < 1) {
 801                 RSA_free(rsa);
 802                 talloc_free(p0);
 803                 return WERR_INTERNAL_ERROR;
 804         }
 805
 806         /*
 807          * To dump the key we can use :
 808          * rk_dumpdata("h5lkey", p0, len);
 809          */
 810         ret = hx509_parse_private_key(*hctx, &_hx509_signature_rsa_with_var_num ,
 811                                        p0, len, HX509_KEY_FORMAT_DER, pk);
 812         memset(p0, 0, len);
 813         talloc_free(p0);
 814         if (ret !=0) {
 815                 RSA_free(rsa);
 816                 return WERR_INTERNAL_ERROR;
 817         }
 818
 819         *_rsa = rsa;
 820         return WERR_OK;
 821 }
 822
 823 static WERROR self_sign_cert(TALLOC_CTX *ctx, hx509_context *hctx, hx509_request *req,
 824                                 time_t lifetime, hx509_private_key *private_key,
 825                                 hx509_cert *cert, DATA_BLOB *guidblob)
 826 {
 827         SubjectPublicKeyInfo spki;
 828         hx509_name subject = NULL;
 829         hx509_ca_tbs tbs;
 830         struct heim_bit_string uniqueid;
 831         int ret;
 832
 833         uniqueid.data = talloc_memdup(ctx, guidblob->data, guidblob->length);
 834         /* uniqueid is a bit string in which each byte represent 1 bit (1 or 0)
 835          * so as 1 byte is 8 bits we need to provision 8 times more space as in the
 836          * blob
 837          */
 838         uniqueid.length = 8 * guidblob->length;
 839
 840         memset(&spki, 0, sizeof(spki));
 841
 842         ret = hx509_request_get_name(*hctx, *req, &subject);
 843         if (ret !=0) {
 844                 talloc_free(uniqueid.data);
 845                 return WERR_INTERNAL_ERROR;
 846         }
 847         ret = hx509_request_get_SubjectPublicKeyInfo(*hctx, *req, &spki);
 848         if (ret !=0) {
 849                 talloc_free(uniqueid.data);
 850                 hx509_name_free(&subject);
 851                 return WERR_INTERNAL_ERROR;
 852         }
 853
 854         ret = hx509_ca_tbs_init(*hctx, &tbs);
 855         if (ret !=0) {
 856                 talloc_free(uniqueid.data);
 857                 hx509_name_free(&subject);
 858                 free_SubjectPublicKeyInfo(&spki);
 859                 return WERR_INTERNAL_ERROR;
 860         }
 861
 862         ret = hx509_ca_tbs_set_spki(*hctx, tbs, &spki);
 863         if (ret !=0) {
 864                 talloc_free(uniqueid.data);
 865                 hx509_name_free(&subject);
 866                 free_SubjectPublicKeyInfo(&spki);
 867                 return WERR_INTERNAL_ERROR;
 868         }
 869         ret = hx509_ca_tbs_set_subject(*hctx, tbs, subject);
 870         if (ret !=0) {
 871                 talloc_free(uniqueid.data);
 872                 hx509_name_free(&subject);
 873                 free_SubjectPublicKeyInfo(&spki);
 874                 hx509_ca_tbs_free(&tbs);
 875                 return WERR_INTERNAL_ERROR;
 876         }
 877         ret = hx509_ca_tbs_set_ca(*hctx, tbs, 1);
 878         if (ret !=0) {
 879                 talloc_free(uniqueid.data);
 880                 hx509_name_free(&subject);
 881                 free_SubjectPublicKeyInfo(&spki);
 882                 hx509_ca_tbs_free(&tbs);
 883                 return WERR_INTERNAL_ERROR;
 884         }
 885         ret = hx509_ca_tbs_set_notAfter_lifetime(*hctx, tbs, lifetime);
 886         if (ret !=0) {
 887                 talloc_free(uniqueid.data);
 888                 hx509_name_free(&subject);
 889                 free_SubjectPublicKeyInfo(&spki);
 890                 hx509_ca_tbs_free(&tbs);
 891                 return WERR_INTERNAL_ERROR;
 892         }
 893         ret = hx509_ca_tbs_set_unique(*hctx, tbs, &uniqueid, &uniqueid);
 894         if (ret !=0) {
 895                 talloc_free(uniqueid.data);
 896                 hx509_name_free(&subject);
 897                 free_SubjectPublicKeyInfo(&spki);
 898                 hx509_ca_tbs_free(&tbs);
 899                 return WERR_INTERNAL_ERROR;
 900         }
 901         ret = hx509_ca_sign_self(*hctx, tbs, *private_key, cert);
 902         if (ret !=0) {
 903                 talloc_free(uniqueid.data);
 904                 hx509_name_free(&subject);
 905                 free_SubjectPublicKeyInfo(&spki);
 906                 hx509_ca_tbs_free(&tbs);
 907                 return WERR_INTERNAL_ERROR;
 908         }
 909         hx509_name_free(&subject);
 910         free_SubjectPublicKeyInfo(&spki);
 911         hx509_ca_tbs_free(&tbs);
 912
 913         return WERR_OK;
 914 }
 915
 916 static WERROR create_req(TALLOC_CTX *ctx, hx509_context *hctx, hx509_request *req,
 917                          hx509_private_key *signer,RSA **rsa, const char *dn)
 918 {
 919         int ret;
 920         SubjectPublicKeyInfo key;
 921
 922         hx509_name name;
 923         WERROR w_err;
 924
 925         w_err = create_heimdal_rsa_key(ctx, hctx, signer, rsa);
 926         if (!W_ERROR_IS_OK(w_err)) {
 927                 return w_err;
 928         }
 929
 930         hx509_request_init(*hctx, req);
 931         ret = hx509_parse_name(*hctx, dn, &name);
 932         if (ret != 0) {
 933                 RSA_free(*rsa);
 934                 hx509_private_key_free(signer);
 935                 hx509_request_free(req);
 936                 hx509_name_free(&name);
 937                 return WERR_INTERNAL_ERROR;
 938         }
 939
 940         ret = hx509_request_set_name(*hctx, *req, name);
 941         if (ret != 0) {
 942                 RSA_free(*rsa);
 943                 hx509_private_key_free(signer);
 944                 hx509_request_free(req);
 945                 hx509_name_free(&name);
 946                 return WERR_INTERNAL_ERROR;
 947         }
 948         hx509_name_free(&name);
 949
 950         ret = hx509_private_key2SPKI(*hctx, *signer, &key);
 951         if (ret != 0) {
 952                 RSA_free(*rsa);
 953                 hx509_private_key_free(signer);
 954                 hx509_request_free(req);
 955                 return WERR_INTERNAL_ERROR;
 956         }
 957         ret = hx509_request_set_SubjectPublicKeyInfo(*hctx, *req, &key);
 958         if (ret != 0) {
 959                 RSA_free(*rsa);
 960                 hx509_private_key_free(signer);
 961                 free_SubjectPublicKeyInfo(&key);
 962                 hx509_request_free(req);
 963                 return WERR_INTERNAL_ERROR;
 964         }
 965
 966         free_SubjectPublicKeyInfo(&key);
 967
 968         return WERR_OK;
 969 }
 970
 971 /* Return an error when we fail to generate a certificate */
 972 static WERROR generate_bkrp_cert(TALLOC_CTX *ctx, struct dcesrv_call_state *dce_call, struct ldb_context *ldb_ctx, const char *dn)
 973 {
 974
 975         struct heim_octet_string data;
 976         WERROR w_err;
 977         RSA *rsa;
 978         hx509_context hctx;
 979         hx509_private_key pk;
 980         hx509_request req;
 981         hx509_cert cert;
 982         DATA_BLOB blob;
 983         DATA_BLOB blobkeypair;
 984         DATA_BLOB *tmp;
 985         int ret;
 986         bool ok = true;
 987         struct GUID guid = GUID_random();
 988         NTSTATUS status;
 989         char *secret_name;
 990         struct bkrp_exported_RSA_key_pair keypair;
 991         enum ndr_err_code ndr_err;
 992         uint32_t nb_days_validity = 365;
 993
 994         DEBUG(6, ("Trying to generate a certificate\n"));
 995         hx509_context_init(&hctx);
 996         w_err = create_req(ctx, &hctx, &req, &pk, &rsa, dn);
 997         if (!W_ERROR_IS_OK(w_err)) {
 998                 hx509_context_free(&hctx);
 999                 return w_err;
1000         }
1001
1002         status = GUID_to_ndr_blob(&guid, ctx, &blob);
1003         if (!NT_STATUS_IS_OK(status)) {
1004                 hx509_context_free(&hctx);
1005                 hx509_private_key_free(&pk);
1006                 RSA_free(rsa);
1007                 return WERR_INVALID_DATA;
1008         }
1009
1010         w_err = self_sign_cert(ctx, &hctx, &req, nb_days_validity, &pk, &cert, &blob);
1011         if (!W_ERROR_IS_OK(w_err)) {
1012                 hx509_private_key_free(&pk);
1013                 hx509_context_free(&hctx);
1014                 return WERR_INVALID_DATA;
1015         }
1016
1017         ret = hx509_cert_binary(hctx, cert, &data);
1018         if (ret !=0) {
1019                 hx509_cert_free(cert);
1020                 hx509_private_key_free(&pk);
1021                 hx509_context_free(&hctx);
1022                 return WERR_INVALID_DATA;
1023         }
1024
1025         keypair.cert.data = talloc_memdup(ctx, data.data, data.length);
1026         keypair.cert.length = data.length;
1027
1028         /*
1029          * Heimdal's bignum are big endian and the
1030          * structure expect it to be in little endian
1031          * so we reverse the buffer to make it work
1032          */
1033         tmp = reverse_and_get_blob(ctx, rsa->e);
1034         if (tmp == NULL) {
1035                 ok = false;
1036         } else {
1037                 keypair.public_exponent = *tmp;
1038                 SMB_ASSERT(tmp->length <= 4);
1039                 /*
1040                  * The value is now in little endian but if can happen that the length is
1041                  * less than 4 bytes.
1042                  * So if we have less than 4 bytes we pad with zeros so that it correctly
1043                  * fit into the structure.
1044                  */
1045                 if (tmp->length < 4) {
1046                         /*
1047                          * We need the expo to fit 4 bytes
1048                          */
1049                         keypair.public_exponent.data = talloc_zero_array(ctx, uint8_t, 4);
1050                         memcpy(keypair.public_exponent.data, tmp->data, tmp->length);
1051                         keypair.public_exponent.length = 4;
1052                 }
1053         }
1054
1055         tmp = reverse_and_get_blob(ctx,rsa->d);
1056         if (tmp == NULL) {
1057                 ok = false;
1058         } else {
1059                 keypair.private_exponent = *tmp;
1060         }
1061
1062         tmp = reverse_and_get_blob(ctx,rsa->n);
1063         if (tmp == NULL) {
1064                 ok = false;
1065         } else {
1066                 keypair.modulus = *tmp;
1067         }
1068
1069         tmp = reverse_and_get_blob(ctx,rsa->p);
1070         if (tmp == NULL) {
1071                 ok = false;
1072         } else {
1073                 keypair.prime1 = *tmp;
1074         }
1075
1076         tmp = reverse_and_get_blob(ctx,rsa->q);
1077         if (tmp == NULL) {
1078                 ok = false;
1079         } else {
1080                 keypair.prime2 = *tmp;
1081         }
1082
1083         tmp = reverse_and_get_blob(ctx,rsa->dmp1);
1084         if (tmp == NULL) {
1085                 ok = false;
1086         } else {
1087                 keypair.exponent1 = *tmp;
1088         }
1089
1090         tmp = reverse_and_get_blob(ctx,rsa->dmq1);
1091         if (tmp == NULL) {
1092                 ok = false;
1093         } else {
1094                 keypair.exponent2 = *tmp;
1095         }
1096
1097         tmp = reverse_and_get_blob(ctx,rsa->iqmp);
1098         if (tmp == NULL) {
1099                 ok = false;
1100         } else {
1101                 keypair.coefficient = *tmp;
1102         }
1103
1104         /* One of the keypair allocation was wrong */
1105         if (ok == false) {
1106                 der_free_octet_string(&data);
1107                 hx509_cert_free(cert);
1108                 hx509_private_key_free(&pk);
1109                 hx509_context_free(&hctx);
1110                 RSA_free(rsa);
1111                 return WERR_INVALID_DATA;
1112         }
1113         keypair.certificate_len = keypair.cert.length;
1114         ndr_err = ndr_push_struct_blob(&blobkeypair, ctx, &keypair, (ndr_push_flags_fn_t)ndr_push_bkrp_exported_RSA_key_pair);
1115         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
1116                 der_free_octet_string(&data);
1117                 hx509_cert_free(cert);
1118                 hx509_private_key_free(&pk);
1119                 hx509_context_free(&hctx);
1120                 RSA_free(rsa);
1121                 return WERR_INVALID_DATA;
1122         }
1123
1124         secret_name = talloc_asprintf(ctx, "BCKUPKEY_%s", GUID_string(ctx, &guid));
1125         if (secret_name == NULL) {
1126                 der_free_octet_string(&data);
1127                 hx509_cert_free(cert);
1128                 hx509_private_key_free(&pk);
1129                 hx509_context_free(&hctx);
1130                 RSA_free(rsa);
1131                 return WERR_OUTOFMEMORY;
1132         }
1133
1134         status = set_lsa_secret(ctx, ldb_ctx, secret_name, &blobkeypair);
1135         if (!NT_STATUS_IS_OK(status)) {
1136                 DEBUG(2, ("Failed to save the secret %s\n", secret_name));
1137         }
1138         talloc_free(secret_name);
1139
1140         GUID_to_ndr_blob(&guid, ctx, &blob);
1141         status = set_lsa_secret(ctx, ldb_ctx, "BCKUPKEY_PREFERRED", &blob);
1142         if (!NT_STATUS_IS_OK(status)) {
1143                 DEBUG(2, ("Failed to save the secret BCKUPKEY_PREFERRED\n"));
1144         }
1145
1146         der_free_octet_string(&data);
1147         hx509_cert_free(cert);
1148         hx509_private_key_free(&pk);
1149         hx509_context_free(&hctx);
1150         RSA_free(rsa);
1151         return WERR_OK;
1152 }
1153
1154 static WERROR bkrp_do_retreive_client_wrap_key(struct dcesrv_call_state *dce_call, TALLOC_CTX *mem_ctx,
1155                 struct bkrp_BackupKey *r ,struct ldb_context *ldb_ctx)
1156 {
1157         struct GUID guid;
1158         char *guid_string;
1159         DATA_BLOB secret;
1160         enum ndr_err_code ndr_err;
1161         NTSTATUS status;
1162
1163         /*
1164          * here we basicaly need to return our certificate
1165          * search for lsa secret BCKUPKEY_PREFERRED first
1166          */
1167
1168         status = get_lsa_secret(mem_ctx,
1169                                 ldb_ctx,
1170                                 "BCKUPKEY_PREFERRED",
1171                                 &secret);
1172         if (!NT_STATUS_IS_OK(status)) {
1173                 DEBUG(10, ("Error while fetching secret BCKUPKEY_PREFERRED\n"));
1174                 if (!NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
1175                         /* Ok we can be in this case if there was no certs */
1176                         struct loadparm_context *lp_ctx = dce_call->conn->dce_ctx->lp_ctx;
1177                         char *dn = talloc_asprintf(mem_ctx, "CN=%s.%s",
1178                                                         lpcfg_netbios_name(lp_ctx),
1179                                                         lpcfg_realm(lp_ctx));
1180
1181                         WERROR werr =  generate_bkrp_cert(mem_ctx, dce_call, ldb_ctx, dn);
1182                         if (!W_ERROR_IS_OK(werr)) {
1183                                 return WERR_INVALID_PARAMETER;
1184                         }
1185                         status = get_lsa_secret(mem_ctx,
1186                                         ldb_ctx,
1187                                         "BCKUPKEY_PREFERRED",
1188                                         &secret);
1189
1190                         if (!NT_STATUS_IS_OK(status)) {
1191                                 /* Ok we really don't manage to get this certs ...*/
1192                                 DEBUG(2, ("Unable to locate BCKUPKEY_PREFERRED after cert generation\n"));
1193                                 return WERR_FILE_NOT_FOUND;
1194                         }
1195                 } else {
1196                         /* In theory we should NEVER reach this point as it
1197                            should only appear in a rodc server */
1198                         /* we do not have the real secret attribute */
1199                         return WERR_INVALID_PARAMETER;
1200                 }
1201         }
1202
1203         if (secret.length != 0) {
1204                 char *cert_secret_name;
1205
1206                 status = GUID_from_ndr_blob(&secret, &guid);
1207                 if (!NT_STATUS_IS_OK(status)) {
1208                         return WERR_FILE_NOT_FOUND;
1209                 }
1210
1211                 guid_string = GUID_string(mem_ctx, &guid);
1212                 if (guid_string == NULL) {
1213                         /* We return file not found because the client
1214                          * expect this error
1215                          */
1216                         return WERR_FILE_NOT_FOUND;
1217                 }
1218
1219                 cert_secret_name = talloc_asprintf(mem_ctx,
1220                                                         "BCKUPKEY_%s",
1221                                                         guid_string);
1222                 status = get_lsa_secret(mem_ctx,
1223                                         ldb_ctx,
1224                                         cert_secret_name,
1225                                         &secret);
1226                 if (!NT_STATUS_IS_OK(status)) {
1227                         return WERR_FILE_NOT_FOUND;
1228                 }
1229
1230                 if (secret.length != 0) {
1231                         struct bkrp_exported_RSA_key_pair keypair;
1232                         ndr_err = ndr_pull_struct_blob(&secret, mem_ctx, &keypair,
1233                                         (ndr_pull_flags_fn_t)ndr_pull_bkrp_exported_RSA_key_pair);
1234                         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
1235                                 return WERR_FILE_NOT_FOUND;
1236                         }
1237                         *(r->out.data_out_len) = keypair.cert.length;
1238                         *(r->out.data_out) = talloc_memdup(mem_ctx, keypair.cert.data, keypair.cert.length);
1239                         W_ERROR_HAVE_NO_MEMORY(*(r->out.data_out));
1240                         return WERR_OK;
1241                 } else {
1242                         DEBUG(10, ("No or broken secret called %s\n", cert_secret_name));
1243                         return WERR_FILE_NOT_FOUND;
1244                 }
1245         } else {
1246                 DEBUG(10, ("No secret BCKUPKEY_PREFERRED\n"));
1247                 return WERR_FILE_NOT_FOUND;
1248         }
1249
1250         return WERR_NOT_SUPPORTED;
1251 }
1252
1253 static WERROR dcesrv_bkrp_BackupKey(struct dcesrv_call_state *dce_call,
1254                                     TALLOC_CTX *mem_ctx, struct bkrp_BackupKey *r)
1255 {
1256         WERROR error = WERR_INVALID_PARAM;
1257         struct ldb_context *ldb_ctx;
1258         bool is_rodc;
1259         const char *addr = "unknown";
1260         /* At which level we start to add more debug of what is done in the protocol */
1261         const int debuglevel = 4;
1262
1263         if (DEBUGLVL(debuglevel)) {
1264                 const struct tsocket_address *remote_address;
1265                 remote_address = dcesrv_connection_get_remote_address(dce_call->conn);
1266                 if (tsocket_address_is_inet(remote_address, "ip")) {
1267                         addr = tsocket_address_inet_addr_string(remote_address, mem_ctx);
1268                         W_ERROR_HAVE_NO_MEMORY(addr);
1269                 }
1270         }
1271
1272         if (lpcfg_server_role(dce_call->conn->dce_ctx->lp_ctx) != ROLE_DOMAIN_CONTROLLER) {
1273                 return WERR_NOT_SUPPORTED;
1274         }
1275
1276         if (!dce_call->conn->auth_state.auth_info ||
1277                 dce_call->conn->auth_state.auth_info->auth_level != DCERPC_AUTH_LEVEL_PRIVACY) {
1278                 DCESRV_FAULT(DCERPC_FAULT_ACCESS_DENIED);
1279         }
1280
1281         ldb_ctx = samdb_connect(mem_ctx, dce_call->event_ctx,
1282                                 dce_call->conn->dce_ctx->lp_ctx,
1283                                 system_session(dce_call->conn->dce_ctx->lp_ctx), 0);
1284
1285         if (samdb_rodc(ldb_ctx, &is_rodc) != LDB_SUCCESS) {
1286                 talloc_unlink(mem_ctx, ldb_ctx);
1287                 return WERR_INVALID_PARAM;
1288         }
1289
1290         if (!is_rodc) {
1291                 if(strncasecmp(GUID_string(mem_ctx, r->in.guidActionAgent),
1292                         BACKUPKEY_RESTORE_GUID, strlen(BACKUPKEY_RESTORE_GUID)) == 0) {
1293                         DEBUG(debuglevel, ("Client %s requested to decrypt a client side wrapped secret\n", addr));
1294                         error = bkrp_do_uncrypt_client_wrap_key(dce_call, mem_ctx, r, ldb_ctx);
1295                 }
1296
1297                 if (strncasecmp(GUID_string(mem_ctx, r->in.guidActionAgent),
1298                         BACKUPKEY_RETRIEVE_BACKUP_KEY_GUID, strlen(BACKUPKEY_RETRIEVE_BACKUP_KEY_GUID)) == 0) {
1299                         DEBUG(debuglevel, ("Client %s requested certificate for client wrapped secret\n", addr));
1300                         error = bkrp_do_retreive_client_wrap_key(dce_call, mem_ctx, r, ldb_ctx);
1301                 }
1302         }
1303         /*else: I am a RODC so I don't handle backup key protocol */
1304
1305         talloc_unlink(mem_ctx, ldb_ctx);
1306         return error;
1307 }
1308
1309 /* include the generated boilerplate */
1310 #include "librpc/gen_ndr/ndr_backupkey_s.c"