/* $Id$
 * reactos security thin manager emulation of libcaptive
 * Copyright (C) 2002-2003 Jan Kratochvil <project-captive@jankratochvil.net>
 * 
 * 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; exactly version 2 of June 1991 is required
 * 
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


#include "config.h"

#include "reactos/ddk/setypes.h"	/* self */
#include <glib/gmessages.h>
#include "reactos/ddk/status.h"
#include "reactos/ddk/exfuncs.h"	/* for ExAllocatePool() */


/**
 * SeLockSubjectContext:
 * @SubjectContext: Security context to read lock.
 * %NULL value is forbidden.
 *
 * Obtain read locks on the security context @SubjectContext.
 * @SubjectContext must be already acquired by SeCaptureSubjectContext().
 *
 * This functions is a NOP in libcaptive as there is no threading implemented.
 * FIXME: No sanity checks are currently done by libcaptive.
 */
VOID SeLockSubjectContext(IN PSECURITY_SUBJECT_CONTEXT SubjectContext)
{
	g_return_if_fail(SubjectContext!=NULL);

	/* NOP; TODO:thread */
}


/**
 * SeUnlockSubjectContext:
 * @SubjectContext: Security context to unlock.
 * %NULL value is forbidden.
 *
 * Release read locks on the security context @SubjectContext.
 * @SubjectContext must be currently locked by SeLockSubjectContext().
 *
 * This functions is a NOP in libcaptive as there is no threading implemented.
 * FIXME: No sanity checks are currently done by libcaptive.
 */
VOID SeUnlockSubjectContext(IN PSECURITY_SUBJECT_CONTEXT SubjectContext)
{
	g_return_if_fail(SubjectContext!=NULL);

	/* NOP; TODO:thread */
}


static SID *SID_dup(SID *sid,SECURITY_DESCRIPTOR *src,SECURITY_DESCRIPTOR *dest,gpointer *destdatap)
{
SID *r;
gsize size;

	/* 'sid' may be NULL */
	g_return_val_if_fail(src!=NULL,NULL);
	g_return_val_if_fail(dest!=NULL,NULL);
	g_return_val_if_fail(destdatap!=NULL,NULL);
	g_return_val_if_fail(*destdatap!=NULL,NULL);

	if (!sid)
		return NULL;
	if (src->Control & SE_SELF_RELATIVE)
		sid=(SID *)(((ULONG)sid)+((ULONG)src));
	if (!sid)
		return NULL;

	size=sizeof(*r)+sizeof(*r->SubAuthority)*(sid->SubAuthorityCount-1);
	g_assert(size==(gsize)((*(guint8 *)(((char *)sid)+0x01))*4+8));	/* 0x14h is sizeof(SECURITY_DESCRIPTOR) */
	g_assert(!(size&3));	/* sizeof(ULONG)-alignment */
	r=*destdatap;
	(*(char **)destdatap)+=size;
	memcpy(r,sid,size);
	if (dest->Control & SE_SELF_RELATIVE)
		r=(SID *)(((ULONG)r)-((ULONG)dest));

	return r;
}

static ACL *ACL_dup(ACL *acl,SECURITY_DESCRIPTOR *src,SECURITY_DESCRIPTOR *dest,gpointer *destdatap)
{
ACL *r;
gsize size;

	/* 'acl' may be NULL */
	g_return_val_if_fail(src!=NULL,NULL);
	g_return_val_if_fail(dest!=NULL,NULL);
	g_return_val_if_fail(destdatap!=NULL,NULL);
	g_return_val_if_fail(*destdatap!=NULL,NULL);

	if (!acl)
		return NULL;
	if (src->Control & SE_SELF_RELATIVE)
		acl=(ACL *)(((ULONG)acl)+((ULONG)src));
	if (!acl)
		r=NULL;
	else {
		/* W32 undocumented: ReactOS uses '&0xFF' notation, I have seen value PAGE_SIZE.
		 * W32 doc says it is a regular size.
		 */
		size=acl->AclSize;
		g_assert(!(size&3));	/* sizeof(ULONG)-alignment */
		r=*destdatap;
		(*(char **)destdatap)+=size;
		memcpy(r,acl,size);
		}
	if (dest->Control & SE_SELF_RELATIVE)
		r=(ACL *)(((ULONG)r)-((ULONG)dest));

	return r;
}

/**
 * SeAssignSecurity:
 * @ParentDescriptor: Optional parent object security descriptor.
 * %NULL value is permitted.
 * @ExplicitDescriptor: Optional overriding descriptor for the new object.
 * FIXME: %NULL value should be permitted but it is currently forbidden by libcaptive.
 * @NewDescriptor: Returns the new generated descriptor.
 * %NULL value is forbidden.
 * @IsDirectoryObject: Will the new object contain its subobjects?
 * @SubjectContext: Security context of the caller.
 * %NULL value is forbidden.
 * @GenericMapping: Rights mapping (?).
 * %NULL value is forbidden.
 * @PoolType: #POOL_TYPE to allocate new @NewDescriptor from.
 *
 * libcaptive requires either @ExplicitDescriptor or @ParentDescriptor
 * to be presents and it recursively copies the structures to the
 * target (allocated) @NewDescriptor. @ExplicitDescriptor is preferred
 * over @ParentDescriptor if present. No structures merging is done.
 *
 * Returns: %STATUS_SUCCESS if @NewDescriptor was successfuly filled.
 */
NTSTATUS SeAssignSecurity(PSECURITY_DESCRIPTOR ParentDescriptor OPTIONAL,
		PSECURITY_DESCRIPTOR ExplicitDescriptor OPTIONAL,PSECURITY_DESCRIPTOR *NewDescriptor,
		BOOLEAN IsDirectoryObject,PSECURITY_SUBJECT_CONTEXT SubjectContext,PGENERIC_MAPPING GenericMapping,POOL_TYPE PoolType)
{
SECURITY_DESCRIPTOR *src,*dest;
ULONG size;
gpointer destdata;

	g_return_val_if_fail(NewDescriptor!=NULL,STATUS_INVALID_PARAMETER);
	g_return_val_if_fail(SubjectContext!=NULL,STATUS_INVALID_PARAMETER);
	g_return_val_if_fail(GenericMapping!=NULL,STATUS_INVALID_PARAMETER);

	/* #2  0x40067021 in SeAssignSecurity (ParentDescriptor=0x0,
	 *     ExplicitDescriptor=0xbfffe7f4, NewDescriptor=0x40b5873c,
	 *     IsDirectoryObject=0 '\0', SubjectContext=0x409d2ff0,
	 *     GenericMapping=0x40088014, PoolType=1) at semgr.c:79
	 * #2  0x4006fe45 in SeAssignSecurity (ParentDescriptor=0x411b3fd0,
	 *     ExplicitDescriptor=0x0, NewDescriptor=0xbfffe39c,
	 *     IsDirectoryObject=1 '\001', SubjectContext=0xbfffe90c,
	 *     GenericMapping=0x40094014, PoolType=1) at semgr.c:99
	 */
	g_return_val_if_fail(ExplicitDescriptor!=NULL || ParentDescriptor!=NULL,STATUS_NOT_IMPLEMENTED);	/* NOT YET IMPLEMENTED */

	src=(ExplicitDescriptor ? ExplicitDescriptor : ParentDescriptor);

	size=RtlLengthSecurityDescriptor(src);
	g_assert(!(size&3));	/* sizeof(ULONG)-alignment */

	dest=ExAllocatePool(PagedPool,size);
	g_return_val_if_fail(dest!=NULL,STATUS_NO_MEMORY);

	dest->Revision=src->Revision;
	dest->Control=src->Control;
	destdata=(dest+1);
	dest->Owner=SID_dup(src->Owner,src,dest,&destdata);
	dest->Group=SID_dup(src->Group,src,dest,&destdata);
	if (src->Control & SE_SACL_PRESENT) {
		/* 'SE_SACL_PRESENT' may be site while 'Sacl==NULL'.
		 * FIXME: How it differs from '!SE_SACL_PRESENT'?
		 */
		dest->Sacl=ACL_dup(src->Sacl,src,dest,&destdata);
		}
	else
		dest->Sacl=NULL;
	if (src->Control & SE_DACL_PRESENT) {
		/* 'SE_DACL_PRESENT' may be site while 'Dacl==NULL'.
		 * FIXME: How it differs from '!SE_DACL_PRESENT'?
		 */
		dest->Dacl=ACL_dup(src->Dacl,src,dest,&destdata);
		}
	else
		dest->Dacl=NULL;

	g_assert(((char *)dest)+size==destdata);

	*NewDescriptor=dest;

	return STATUS_SUCCESS;
}


/**
 * SeAccessCheck:
 * @SecurityDescriptor: IGNORED; ignored by libcaptive.
 * %NULL value is forbidden.
 * @SubjectSecurityContext: IGNORED; ignored by libcaptive.
 * %NULL value is forbidden.
 * @SubjectContextLocked: IGNORED; ignored by libcaptive.
 * @DesiredAccess: IGNORED; ignored by libcaptive.
 * @PreviouslyGrantedAccess: IGNORED; ignored by libcaptive.
 * @Privileges: IGNORED; ignored by libcaptive.
 * %NULL value is forbidden.
 * @GenericMapping: IGNORED; ignored by libcaptive.
 * %NULL value is forbidden.
 * @AccessMode: IGNORED; ignored by libcaptive.
 * @GrantedAccess: IGNORED; ignored by libcaptive.
 * %NULL value is forbidden.
 * @AccessStatus: IGNORED; ignored by libcaptive.
 * %NULL value is forbidden.
 * 
 * Query the rights of IGNORED to access IGNORED.
 *
 * libcaptive does not support any security and therefore it always returns %TRUE.
 *
 * Returns: %TRUE if the access is granted.
 */
BOOLEAN SeAccessCheck(IN PSECURITY_DESCRIPTOR SecurityDescriptor,IN PSECURITY_SUBJECT_CONTEXT SubjectSecurityContext,
		IN BOOLEAN SubjectContextLocked,IN ACCESS_MASK DesiredAccess,IN ACCESS_MASK PreviouslyGrantedAccess,
		OUT PPRIVILEGE_SET* Privileges,IN PGENERIC_MAPPING GenericMapping,IN KPROCESSOR_MODE AccessMode,
		OUT PACCESS_MODE GrantedAccess,OUT PNTSTATUS AccessStatus)
{
	g_return_val_if_fail(SecurityDescriptor!=NULL,FALSE);	/* means 'access denied' */
	g_return_val_if_fail(SubjectSecurityContext!=NULL,FALSE);	/* means 'access denied' */
	g_return_val_if_fail(Privileges!=NULL,FALSE);	/* means 'access denied' */
	g_return_val_if_fail(GenericMapping!=NULL,FALSE);	/* means 'access denied' */
	g_return_val_if_fail(GrantedAccess!=NULL,FALSE);	/* means 'access denied' */
	g_return_val_if_fail(AccessStatus!=NULL,FALSE);	/* means 'access denied' */

	return TRUE;	/* access granted */
}