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/*
* Unix SMB/CIFS implementation.
* Group Policy Object Support
* Copyright (C) Guenther Deschner 2007
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "includes.h"
/* When modifiying security filtering with gpmc.msc (on w2k3) the
* following ACE is created in the DACL:
------- ACE (type: 0x05, flags: 0x02, size: 0x38, mask: 0x100, object flags: 0x1)
access SID: $SID
access type: ALLOWED OBJECT
Permissions:
[Apply Group Policy] (0x00000100)
------- ACE (type: 0x00, flags: 0x02, size: 0x24, mask: 0x20014)
access SID: $SID
access type: ALLOWED
Permissions:
[List Contents] (0x00000004)
[Read All Properties] (0x00000010)
[Read Permissions] (0x00020000)
* by default all "Authenticated Users" (S-1-5-11) have an ALLOW
* OBJECT ace with SEC_RIGHTS_APPLY_GROUP_POLICY mask */
/****************************************************************
****************************************************************/
static BOOL gpo_sd_check_agp_access_bits(uint32 access_mask)
{
return (access_mask & SEC_RIGHTS_APPLY_GROUP_POLICY);
}
/****************************************************************
****************************************************************/
static BOOL gpo_sd_check_read_access_bits(uint32 access_mask)
{
uint32 read_bits = SEC_RIGHTS_LIST_CONTENTS |
SEC_RIGHTS_READ_ALL_PROP |
SEC_RIGHTS_READ_PERMS;
return (read_bits == (access_mask & read_bits));
}
/****************************************************************
****************************************************************/
static BOOL gpo_sd_check_trustee_in_sid_token(const DOM_SID *trustee,
const struct GPO_SID_TOKEN *token)
{
int i;
if (sid_equal(trustee, &token->object_sid)) {
return True;
}
if (sid_equal(trustee, &token->primary_group_sid)) {
return True;
}
for (i = 0; i < token->num_token_sids; i++) {
if (sid_equal(trustee, &token->token_sids[i])) {
return True;
}
}
return False;
}
/****************************************************************
****************************************************************/
static NTSTATUS gpo_sd_check_ace_denied_object(const SEC_ACE *ace,
const struct GPO_SID_TOKEN *token)
{
if (gpo_sd_check_agp_access_bits(ace->access_mask) &&
gpo_sd_check_trustee_in_sid_token(&ace->trustee, token)) {
DEBUG(10,("gpo_sd_check_ace_denied_object: Access denied as of ace for %s\n",
sid_string_static(&ace->trustee)));
return NT_STATUS_ACCESS_DENIED;
}
return STATUS_MORE_ENTRIES;
}
/****************************************************************
****************************************************************/
static NTSTATUS gpo_sd_check_ace_allowed_object(const SEC_ACE *ace,
const struct GPO_SID_TOKEN *token)
{
if (gpo_sd_check_agp_access_bits(ace->access_mask) &&
gpo_sd_check_trustee_in_sid_token(&ace->trustee, token)) {
DEBUG(10,("gpo_sd_check_ace_allowed_object: Access granted as of ace for %s\n",
sid_string_static(&ace->trustee)));
return NT_STATUS_OK;
}
return STATUS_MORE_ENTRIES;
}
/****************************************************************
****************************************************************/
static NTSTATUS gpo_sd_check_ace(const SEC_ACE *ace,
const struct GPO_SID_TOKEN *token)
{
switch (ace->type) {
case SEC_ACE_TYPE_ACCESS_DENIED_OBJECT:
return gpo_sd_check_ace_denied_object(ace, token);
case SEC_ACE_TYPE_ACCESS_ALLOWED_OBJECT:
return gpo_sd_check_ace_allowed_object(ace, token);
default:
return STATUS_MORE_ENTRIES;
}
}
/****************************************************************
****************************************************************/
NTSTATUS gpo_apply_security_filtering(const struct GROUP_POLICY_OBJECT *gpo,
const struct GPO_SID_TOKEN *token)
{
SEC_DESC *sd = gpo->security_descriptor;
SEC_ACL *dacl = NULL;
NTSTATUS status = NT_STATUS_ACCESS_DENIED;
int i;
if (!token) {
return NT_STATUS_INVALID_USER_BUFFER;
}
if (!sd) {
return NT_STATUS_INVALID_SECURITY_DESCR;
}
dacl = sd->dacl;
if (!dacl) {
return NT_STATUS_INVALID_SECURITY_DESCR;
}
/* check all aces and only return NT_STATUS_OK (== Access granted) or
* NT_STATUS_ACCESS_DENIED ( == Access denied) - the default is to
* deny access */
for (i = 0; i < dacl->num_aces; i ++) {
status = gpo_sd_check_ace(&dacl->aces[i], token);
if (NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
return status;
} else if (NT_STATUS_IS_OK(status)) {
return status;
}
continue;
}
return NT_STATUS_ACCESS_DENIED;
}
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