source3/modules/vfs_acl_common.c

   1 /*
   2  * Store Windows ACLs in data store - common functions.
   3  * #included into modules/vfs_acl_xattr.c and modules/vfs_acl_tdb.c
   4  *
   5  * Copyright (C) Volker Lendecke, 2008
   6  * Copyright (C) Jeremy Allison, 2009
   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 static NTSTATUS create_acl_blob(const struct security_descriptor *psd,
  23                         DATA_BLOB *pblob,
  24                         uint16_t hash_type,
  25                         uint8_t hash[XATTR_SD_HASH_SIZE]);
  26
  27 static NTSTATUS get_acl_blob(TALLOC_CTX *ctx,
  28                         vfs_handle_struct *handle,
  29                         files_struct *fsp,
  30                         const char *name,
  31                         DATA_BLOB *pblob);
  32
  33 static NTSTATUS store_acl_blob_fsp(vfs_handle_struct *handle,
  34                         files_struct *fsp,
  35                         DATA_BLOB *pblob);
  36
  37 static NTSTATUS store_acl_blob_pathname(vfs_handle_struct *handle,
  38                         const char *fname,
  39                         DATA_BLOB *pblob);
  40
  41 #define HASH_SECURITY_INFO (OWNER_SECURITY_INFORMATION | \
  42                                 GROUP_SECURITY_INFORMATION | \
  43                                 DACL_SECURITY_INFORMATION | \
  44                                 SACL_SECURITY_INFORMATION)
  45
  46 /*******************************************************************
  47  Hash a security descriptor.
  48 *******************************************************************/
  49
  50 static NTSTATUS hash_sd_sha256(struct security_descriptor *psd,
  51                         uint8_t *hash)
  52 {
  53         DATA_BLOB blob;
  54         SHA256_CTX tctx;
  55         NTSTATUS status;
  56
  57         memset(hash, '\0', XATTR_SD_HASH_SIZE);
  58         status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
  59         if (!NT_STATUS_IS_OK(status)) {
  60                 return status;
  61         }
  62
  63         SHA256_Init(&tctx);
  64         SHA256_Update(&tctx, blob.data, blob.length);
  65         SHA256_Final(hash, &tctx);
  66
  67         return NT_STATUS_OK;
  68 }
  69
  70 /*******************************************************************
  71  Parse out a struct security_descriptor from a DATA_BLOB.
  72 *******************************************************************/
  73
  74 static NTSTATUS parse_acl_blob(const DATA_BLOB *pblob,
  75                                 struct security_descriptor **ppdesc,
  76                                 uint16_t *p_hash_type,
  77                                 uint8_t hash[XATTR_SD_HASH_SIZE])
  78 {
  79         TALLOC_CTX *ctx = talloc_tos();
  80         struct xattr_NTACL xacl;
  81         enum ndr_err_code ndr_err;
  82         size_t sd_size;
  83
  84         ndr_err = ndr_pull_struct_blob(pblob, ctx, NULL, &xacl,
  85                         (ndr_pull_flags_fn_t)ndr_pull_xattr_NTACL);
  86
  87         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
  88                 DEBUG(5, ("parse_acl_blob: ndr_pull_xattr_NTACL failed: %s\n",
  89                         ndr_errstr(ndr_err)));
  90                 return ndr_map_error2ntstatus(ndr_err);;
  91         }
  92
  93         switch (xacl.version) {
  94                 case 2:
  95                         *ppdesc = make_sec_desc(ctx, SEC_DESC_REVISION,
  96                                         xacl.info.sd_hs2->sd->type | SEC_DESC_SELF_RELATIVE,
  97                                         xacl.info.sd_hs2->sd->owner_sid,
  98                                         xacl.info.sd_hs2->sd->group_sid,
  99                                         xacl.info.sd_hs2->sd->sacl,
 100                                         xacl.info.sd_hs2->sd->dacl,
 101                                         &sd_size);
 102                         /* No hash - null out. */
 103                         *p_hash_type = XATTR_SD_HASH_TYPE_NONE;
 104                         memset(hash, '\0', XATTR_SD_HASH_SIZE);
 105                         break;
 106                 case 3:
 107                         *ppdesc = make_sec_desc(ctx, SEC_DESC_REVISION,
 108                                         xacl.info.sd_hs3->sd->type | SEC_DESC_SELF_RELATIVE,
 109                                         xacl.info.sd_hs3->sd->owner_sid,
 110                                         xacl.info.sd_hs3->sd->group_sid,
 111                                         xacl.info.sd_hs3->sd->sacl,
 112                                         xacl.info.sd_hs3->sd->dacl,
 113                                         &sd_size);
 114                         *p_hash_type = xacl.info.sd_hs3->hash_type;
 115                         /* Current version 3. */
 116                         memcpy(hash, xacl.info.sd_hs3->hash, XATTR_SD_HASH_SIZE);
 117                         break;
 118                 default:
 119                         return NT_STATUS_REVISION_MISMATCH;
 120         }
 121
 122         TALLOC_FREE(xacl.info.sd);
 123
 124         return (*ppdesc != NULL) ? NT_STATUS_OK : NT_STATUS_NO_MEMORY;
 125 }
 126
 127 /*******************************************************************
 128  Create a DATA_BLOB from a security descriptor.
 129 *******************************************************************/
 130
 131 static NTSTATUS create_acl_blob(const struct security_descriptor *psd,
 132                         DATA_BLOB *pblob,
 133                         uint16_t hash_type,
 134                         uint8_t hash[XATTR_SD_HASH_SIZE])
 135 {
 136         struct xattr_NTACL xacl;
 137         struct security_descriptor_hash_v3 sd_hs3;
 138         enum ndr_err_code ndr_err;
 139         TALLOC_CTX *ctx = talloc_tos();
 140
 141         ZERO_STRUCT(xacl);
 142         ZERO_STRUCT(sd_hs3);
 143
 144         xacl.version = 3;
 145         xacl.info.sd_hs3 = &sd_hs3;
 146         xacl.info.sd_hs3->sd = CONST_DISCARD(struct security_descriptor *, psd);
 147         xacl.info.sd_hs3->hash_type = hash_type;
 148         memcpy(&xacl.info.sd_hs3->hash[0], hash, XATTR_SD_HASH_SIZE);
 149
 150         ndr_err = ndr_push_struct_blob(
 151                         pblob, ctx, NULL, &xacl,
 152                         (ndr_push_flags_fn_t)ndr_push_xattr_NTACL);
 153
 154         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 155                 DEBUG(5, ("create_acl_blob: ndr_push_xattr_NTACL failed: %s\n",
 156                         ndr_errstr(ndr_err)));
 157                 return ndr_map_error2ntstatus(ndr_err);;
 158         }
 159
 160         return NT_STATUS_OK;
 161 }
 162
 163 /*******************************************************************
 164  Store a DATA_BLOB into an xattr given a pathname.
 165 *******************************************************************/
 166
 167 static NTSTATUS get_nt_acl_internal(vfs_handle_struct *handle,
 168                                 files_struct *fsp,
 169                                 const char *name,
 170                                 uint32_t security_info,
 171                                 struct security_descriptor **ppdesc)
 172 {
 173         DATA_BLOB blob;
 174         NTSTATUS status;
 175         uint16_t hash_type;
 176         uint8_t hash[XATTR_SD_HASH_SIZE];
 177         uint8_t hash_tmp[XATTR_SD_HASH_SIZE];
 178         struct security_descriptor *pdesc_next = NULL;
 179
 180         if (fsp && name == NULL) {
 181                 name = fsp->fsp_name->base_name;
 182         }
 183
 184         DEBUG(10, ("get_nt_acl_internal: name=%s\n", name));
 185
 186         status = get_acl_blob(talloc_tos(), handle, fsp, name, &blob);
 187         if (!NT_STATUS_IS_OK(status)) {
 188                 DEBUG(10, ("get_acl_blob returned %s\n", nt_errstr(status)));
 189                 return status;
 190         }
 191
 192         status = parse_acl_blob(&blob, ppdesc,
 193                                 &hash_type, &hash[0]);
 194         if (!NT_STATUS_IS_OK(status)) {
 195                 DEBUG(10, ("parse_acl_blob returned %s\n",
 196                                 nt_errstr(status)));
 197                 return status;
 198         }
 199
 200         /* Ensure the hash type is one we know. */
 201         switch (hash_type) {
 202                 case XATTR_SD_HASH_TYPE_NONE:
 203                         /* No hash, goto return blob sd. */
 204                         goto out;
 205                 case XATTR_SD_HASH_TYPE_SHA256:
 206                         break;
 207                 default:
 208                         return NT_STATUS_REVISION_MISMATCH;
 209         }
 210
 211         /* Get the full underlying sd, then hash. */
 212         if (fsp) {
 213                 status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 214                                 fsp,
 215                                 HASH_SECURITY_INFO,
 216                                 &pdesc_next);
 217         } else {
 218                 status = SMB_VFS_NEXT_GET_NT_ACL(handle,
 219                                 name,
 220                                 HASH_SECURITY_INFO,
 221                                 &pdesc_next);
 222         }
 223
 224         if (!NT_STATUS_IS_OK(status)) {
 225                 goto out;
 226         }
 227
 228         status = hash_sd_sha256(pdesc_next, hash_tmp);
 229         if (!NT_STATUS_IS_OK(status)) {
 230                 goto out;
 231         }
 232
 233         if (memcmp(&hash[0], &hash_tmp[0], XATTR_SD_HASH_SIZE) == 0) {
 234                 TALLOC_FREE(pdesc_next);
 235                 /* Hash matches, return blob sd. */
 236                 goto out;
 237         }
 238
 239         /* Hash doesn't match, return underlying sd. */
 240
 241         if (!(security_info & OWNER_SECURITY_INFORMATION)) {
 242                 pdesc_next->owner_sid = NULL;
 243         }
 244         if (!(security_info & GROUP_SECURITY_INFORMATION)) {
 245                 pdesc_next->group_sid = NULL;
 246         }
 247         if (!(security_info & DACL_SECURITY_INFORMATION)) {
 248                 pdesc_next->dacl = NULL;
 249         }
 250         if (!(security_info & SACL_SECURITY_INFORMATION)) {
 251                 pdesc_next->sacl = NULL;
 252         }
 253
 254         TALLOC_FREE(*ppdesc);
 255         *ppdesc = pdesc_next;
 256
 257   out:
 258
 259         if (!(security_info & OWNER_SECURITY_INFORMATION)) {
 260                 (*ppdesc)->owner_sid = NULL;
 261         }
 262         if (!(security_info & GROUP_SECURITY_INFORMATION)) {
 263                 (*ppdesc)->group_sid = NULL;
 264         }
 265         if (!(security_info & DACL_SECURITY_INFORMATION)) {
 266                 (*ppdesc)->dacl = NULL;
 267         }
 268         if (!(security_info & SACL_SECURITY_INFORMATION)) {
 269                 (*ppdesc)->sacl = NULL;
 270         }
 271
 272         TALLOC_FREE(blob.data);
 273         return status;
 274 }
 275
 276 /*********************************************************************
 277  Create a default security descriptor for a file in case no inheritance
 278  exists. All permissions to the owner and SYSTEM.
 279 *********************************************************************/
 280
 281 static struct security_descriptor *default_file_sd(TALLOC_CTX *mem_ctx,
 282                                                 SMB_STRUCT_STAT *psbuf,
 283                                                 bool force_inherit)
 284 {
 285         struct dom_sid owner_sid, group_sid;
 286         size_t sd_size;
 287         struct security_ace *pace = NULL;
 288         struct security_acl *pacl = NULL;
 289
 290         uid_to_sid(&owner_sid, psbuf->st_ex_uid);
 291         gid_to_sid(&group_sid, psbuf->st_ex_gid);
 292
 293         pace = TALLOC_ARRAY(mem_ctx, struct security_ace, 2);
 294         if (!pace) {
 295                 return NULL;
 296         }
 297
 298         /* If force_inherit is set, this means we are initializing the ACEs for
 299          * a container and we want the ACEs for owner_sid and "SYSTEM" to be
 300          * inheritable by their children (See Bug #6802).
 301          */
 302
 303         init_sec_ace(&pace[0], &owner_sid, SEC_ACE_TYPE_ACCESS_ALLOWED,
 304                         SEC_RIGHTS_FILE_ALL, (force_inherit ?
 305                                         (SEC_ACE_FLAG_OBJECT_INHERIT|
 306                                         SEC_ACE_FLAG_CONTAINER_INHERIT) :
 307                                         0));
 308
 309         init_sec_ace(&pace[1], &global_sid_System, SEC_ACE_TYPE_ACCESS_ALLOWED,
 310                         SEC_RIGHTS_FILE_ALL, (force_inherit ?
 311                                         (SEC_ACE_FLAG_OBJECT_INHERIT|
 312                                         SEC_ACE_FLAG_CONTAINER_INHERIT) :
 313                                         0));
 314
 315         pacl = make_sec_acl(mem_ctx,
 316                                 NT4_ACL_REVISION,
 317                                 2,
 318                                 pace);
 319         if (!pacl) {
 320                 return NULL;
 321         }
 322         return make_sec_desc(mem_ctx,
 323                         SECURITY_DESCRIPTOR_REVISION_1,
 324                         SEC_DESC_SELF_RELATIVE|SEC_DESC_DACL_PRESENT,
 325                         &owner_sid,
 326                         &group_sid,
 327                         NULL,
 328                         pacl,
 329                         &sd_size);
 330 }
 331
 332 /*********************************************************************
 333 *********************************************************************/
 334
 335 static NTSTATUS inherit_new_acl(vfs_handle_struct *handle,
 336                                         struct smb_filename *smb_fname,
 337                                         files_struct *fsp,
 338                                         bool container)
 339 {
 340         TALLOC_CTX *ctx = talloc_tos();
 341         NTSTATUS status;
 342         struct security_descriptor *parent_desc = NULL;
 343         struct security_descriptor *psd = NULL;
 344         struct security_descriptor *pdesc_next = NULL;
 345         DATA_BLOB blob;
 346         size_t size;
 347         char *parent_name;
 348         bool force_inherit = false;
 349         uint8_t hash[XATTR_SD_HASH_SIZE];
 350
 351         if (!parent_dirname(ctx, smb_fname->base_name, &parent_name, NULL)) {
 352                 return NT_STATUS_NO_MEMORY;
 353         }
 354
 355         DEBUG(10,("inherit_new_acl: check directory %s\n",
 356                         parent_name));
 357
 358         status = get_nt_acl_internal(handle,
 359                                 NULL,
 360                                 parent_name,
 361                                 (OWNER_SECURITY_INFORMATION |
 362                                  GROUP_SECURITY_INFORMATION |
 363                                  DACL_SECURITY_INFORMATION),
 364                                 &parent_desc);
 365         if (NT_STATUS_IS_OK(status)) {
 366                 /* Create an inherited descriptor from the parent. */
 367
 368                 if (DEBUGLEVEL >= 10) {
 369                         DEBUG(10,("inherit_new_acl: parent acl is:\n"));
 370                         NDR_PRINT_DEBUG(security_descriptor, parent_desc);
 371                 }
 372
 373                 status = se_create_child_secdesc(ctx,
 374                                 &psd,
 375                                 &size,
 376                                 parent_desc,
 377                                 &handle->conn->server_info->ptok->user_sids[PRIMARY_USER_SID_INDEX],
 378                                 &handle->conn->server_info->ptok->user_sids[PRIMARY_GROUP_SID_INDEX],
 379                                 container);
 380                 if (!NT_STATUS_IS_OK(status)) {
 381                         return status;
 382                 }
 383
 384                 if (DEBUGLEVEL >= 10) {
 385                         DEBUG(10,("inherit_new_acl: child acl is:\n"));
 386                         NDR_PRINT_DEBUG(security_descriptor, psd);
 387                 }
 388
 389         } else {
 390                 DEBUG(10,("inherit_new_acl: directory %s failed "
 391                         "to get acl %s\n",
 392                         parent_name,
 393                         nt_errstr(status) ));
 394         }
 395
 396         if (!psd || psd->dacl == NULL) {
 397
 398                 TALLOC_FREE(psd);
 399                 if (fsp) {
 400                         status = vfs_stat_fsp(fsp);
 401                         smb_fname->st = fsp->fsp_name->st;
 402                 } else {
 403                         int ret;
 404                         if (lp_posix_pathnames()) {
 405                                 ret = SMB_VFS_LSTAT(handle->conn, smb_fname);
 406                         } else {
 407                                 ret = SMB_VFS_STAT(handle->conn, smb_fname);
 408                         }
 409                         if (ret == -1) {
 410                                 status = map_nt_error_from_unix(errno);
 411                         }
 412                 }
 413                 if (!NT_STATUS_IS_OK(status)) {
 414                         return status;
 415                 }
 416
 417                 /* If we get here, we could have the following possibilities:
 418                  *      1. No ACLs exist on the parent container.
 419                  *      2. ACLs exist on the parent container but they were
 420                  *      not inheritable.
 421                  *
 422                  *      Check to see if case #1 occurred.
 423                  *
 424                  */
 425                 if (container &&
 426                         (parent_desc == NULL || parent_desc->dacl == NULL)) {
 427
 428                         /* If no parent descriptor exists, then there were
 429                          * no ACLs on the parent and then we must create
 430                          * the ACLs on this newly created folder so that they
 431                          * will be inherited by their children (See Bug #6802).
 432                          */
 433
 434                         force_inherit = true;
 435                 }
 436
 437                 psd = default_file_sd(ctx, &smb_fname->st, force_inherit);
 438                 if (!psd) {
 439                         return NT_STATUS_NO_MEMORY;
 440                 }
 441
 442                 if (DEBUGLEVEL >= 10) {
 443                         DEBUG(10,("inherit_new_acl: default acl is:\n"));
 444                         NDR_PRINT_DEBUG(security_descriptor, psd);
 445                 }
 446         }
 447
 448         /* Object exists. Read the current SD to get the hash. */
 449         if (fsp) {
 450                 status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 451                                 fsp,
 452                                 HASH_SECURITY_INFO,
 453                                 &pdesc_next);
 454         } else {
 455                 status = SMB_VFS_NEXT_GET_NT_ACL(handle,
 456                                 smb_fname->base_name,
 457                                 HASH_SECURITY_INFO,
 458                                 &pdesc_next);
 459         }
 460
 461         if (!NT_STATUS_IS_OK(status)) {
 462                 return status;
 463         }
 464
 465         status = hash_sd_sha256(pdesc_next, hash);
 466         if (!NT_STATUS_IS_OK(status)) {
 467                 return status;
 468         }
 469         status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
 470         if (!NT_STATUS_IS_OK(status)) {
 471                 return status;
 472         }
 473         if (fsp) {
 474                 return store_acl_blob_fsp(handle, fsp, &blob);
 475         } else {
 476                 return store_acl_blob_pathname(handle, smb_fname->base_name,
 477                                                &blob);
 478         }
 479 }
 480
 481 /*********************************************************************
 482  Check ACL on open. For new files inherit from parent directory.
 483 *********************************************************************/
 484
 485 static int open_acl_common(vfs_handle_struct *handle,
 486                         struct smb_filename *smb_fname,
 487                         files_struct *fsp,
 488                         int flags,
 489                         mode_t mode)
 490 {
 491         uint32_t access_granted = 0;
 492         struct security_descriptor *pdesc = NULL;
 493         bool file_existed = true;
 494         char *fname = NULL;
 495         NTSTATUS status;
 496
 497         if (fsp->base_fsp) {
 498                 /* Stream open. Base filename open already did the ACL check. */
 499                 DEBUG(10,("open_acl_common: stream open on %s\n",
 500                         smb_fname_str_dbg(smb_fname) ));
 501                 return SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
 502         }
 503
 504         status = get_full_smb_filename(talloc_tos(), smb_fname,
 505                                        &fname);
 506         if (!NT_STATUS_IS_OK(status)) {
 507                 errno = map_errno_from_nt_status(status);
 508                 return -1;
 509         }
 510
 511         status = get_nt_acl_internal(handle,
 512                                 NULL,
 513                                 fname,
 514                                 (OWNER_SECURITY_INFORMATION |
 515                                  GROUP_SECURITY_INFORMATION |
 516                                  DACL_SECURITY_INFORMATION),
 517                                 &pdesc);
 518         if (NT_STATUS_IS_OK(status)) {
 519                 /* See if we can access it. */
 520                 status = smb1_file_se_access_check(pdesc,
 521                                         handle->conn->server_info->ptok,
 522                                         fsp->access_mask,
 523                                         &access_granted);
 524                 if (!NT_STATUS_IS_OK(status)) {
 525                         DEBUG(10,("open_acl_xattr: file %s open "
 526                                 "refused with error %s\n",
 527                                 smb_fname_str_dbg(smb_fname),
 528                                 nt_errstr(status) ));
 529                         errno = map_errno_from_nt_status(status);
 530                         return -1;
 531                 }
 532         } else if (NT_STATUS_EQUAL(status,NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
 533                 file_existed = false;
 534         }
 535
 536         DEBUG(10,("open_acl_xattr: get_nt_acl_attr_internal for "
 537                 "file %s returned %s\n",
 538                 smb_fname_str_dbg(smb_fname),
 539                 nt_errstr(status) ));
 540
 541         fsp->fh->fd = SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
 542
 543         if (!file_existed && fsp->fh->fd != -1) {
 544                 /* File was created. Inherit from parent directory. */
 545                 status = fsp_set_smb_fname(fsp, smb_fname);
 546                 if (!NT_STATUS_IS_OK(status)) {
 547                         errno = map_errno_from_nt_status(status);
 548                         return -1;
 549                 }
 550                 inherit_new_acl(handle, smb_fname, fsp, false);
 551         }
 552
 553         return fsp->fh->fd;
 554 }
 555
 556 static int mkdir_acl_common(vfs_handle_struct *handle, const char *path, mode_t mode)
 557 {
 558         struct smb_filename *smb_fname = NULL;
 559         int ret = SMB_VFS_NEXT_MKDIR(handle, path, mode);
 560         NTSTATUS status;
 561
 562         if (ret == -1) {
 563                 return ret;
 564         }
 565
 566         status = create_synthetic_smb_fname(talloc_tos(), path, NULL, NULL,
 567                                             &smb_fname);
 568         if (!NT_STATUS_IS_OK(status)) {
 569                 errno = map_errno_from_nt_status(status);
 570                 return -1;
 571         }
 572
 573         /* New directory - inherit from parent. */
 574         inherit_new_acl(handle, smb_fname, NULL, true);
 575         TALLOC_FREE(smb_fname);
 576         return ret;
 577 }
 578
 579 /*********************************************************************
 580  Fetch a security descriptor given an fsp.
 581 *********************************************************************/
 582
 583 static NTSTATUS fget_nt_acl_common(vfs_handle_struct *handle, files_struct *fsp,
 584         uint32_t security_info, struct security_descriptor **ppdesc)
 585 {
 586         return get_nt_acl_internal(handle, fsp,
 587                                 NULL, security_info, ppdesc);
 588 }
 589
 590 /*********************************************************************
 591  Fetch a security descriptor given a pathname.
 592 *********************************************************************/
 593
 594 static NTSTATUS get_nt_acl_common(vfs_handle_struct *handle,
 595         const char *name, uint32_t security_info, struct security_descriptor **ppdesc)
 596 {
 597         return get_nt_acl_internal(handle, NULL,
 598                                 name, security_info, ppdesc);
 599 }
 600
 601 /*********************************************************************
 602  Store a security descriptor given an fsp.
 603 *********************************************************************/
 604
 605 static NTSTATUS fset_nt_acl_common(vfs_handle_struct *handle, files_struct *fsp,
 606         uint32_t security_info_sent, const struct security_descriptor *psd)
 607 {
 608         NTSTATUS status;
 609         DATA_BLOB blob;
 610         struct security_descriptor *pdesc_next = NULL;
 611         uint8_t hash[XATTR_SD_HASH_SIZE];
 612
 613         if (DEBUGLEVEL >= 10) {
 614                 DEBUG(10,("fset_nt_acl_xattr: incoming sd for file %s\n",
 615                           fsp_str_dbg(fsp)));
 616                 NDR_PRINT_DEBUG(security_descriptor,
 617                         CONST_DISCARD(struct security_descriptor *,psd));
 618         }
 619
 620         /* Ensure owner and group are set. */
 621         if (!psd->owner_sid || !psd->group_sid) {
 622                 DOM_SID owner_sid, group_sid;
 623                 struct security_descriptor *nc_psd = dup_sec_desc(talloc_tos(), psd);
 624
 625                 if (!nc_psd) {
 626                         return NT_STATUS_OK;
 627                 }
 628                 status = vfs_stat_fsp(fsp);
 629                 if (!NT_STATUS_IS_OK(status)) {
 630                         /* Lower level acl set succeeded,
 631                          * so still return OK. */
 632                         return NT_STATUS_OK;
 633                 }
 634                 create_file_sids(&fsp->fsp_name->st, &owner_sid, &group_sid);
 635                 /* This is safe as nc_psd is discarded at fn exit. */
 636                 nc_psd->owner_sid = &owner_sid;
 637                 nc_psd->group_sid = &group_sid;
 638                 security_info_sent |= (OWNER_SECURITY_INFORMATION|GROUP_SECURITY_INFORMATION);
 639                 psd = nc_psd;
 640         }
 641
 642         status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
 643         if (!NT_STATUS_IS_OK(status)) {
 644                 return status;
 645         }
 646
 647         /* Get the full underlying sd, then hash. */
 648         status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 649                                 fsp,
 650                                 HASH_SECURITY_INFO,
 651                                 &pdesc_next);
 652
 653         if (!NT_STATUS_IS_OK(status)) {
 654                 return status;
 655         }
 656
 657         status = hash_sd_sha256(pdesc_next, hash);
 658         if (!NT_STATUS_IS_OK(status)) {
 659                 return status;
 660         }
 661
 662         if (DEBUGLEVEL >= 10) {
 663                 DEBUG(10,("fset_nt_acl_xattr: storing xattr sd for file %s\n",
 664                           fsp_str_dbg(fsp)));
 665                 NDR_PRINT_DEBUG(security_descriptor,
 666                         CONST_DISCARD(struct security_descriptor *,psd));
 667         }
 668         create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
 669         store_acl_blob_fsp(handle, fsp, &blob);
 670
 671         return NT_STATUS_OK;
 672 }