;@echo off
;goto make

;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
;
;  FileWorks - File creation, writing, reading etc...
;
;  Written by Four-F (four-f@mail.ru)
;
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

.386
.model flat, stdcall
option casemap:none

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;                                  I N C L U D E   F I L E S                                        
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

include \masm32\include\w2k\ntstatus.inc
include \masm32\include\w2k\ntifs.inc
include \masm32\include\w2k\ntoskrnl.inc

includelib \masm32\lib\w2k\ntoskrnl.lib

include \masm32\Macros\Strings.mac

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;                                 R E A D O N L Y    D A T A                                        
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

.const

CCOUNTED_UNICODE_STRING	"\\??\\c:\\FileWorks\\test.txt", g_usFileName, 4
CCOUNTED_UNICODE_STRING	"\\??\\c:\\FileWorks", g_usDirName, 4

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;                                         C O D E                                                   
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

.code

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;                                      CreateDirectory                                              
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

CreateDirectory proc

local oa:OBJECT_ATTRIBUTES
local iosb:IO_STATUS_BLOCK
local hDirectory:HANDLE

	; Remember that the Unicode format codes (%C, %S, %lc, %ls, %wc, %ws, %wZ)
	; can only be used at IRQL PASSIVE_LEVEL. 
	invoke DbgPrint, $CTA0("\nFileWorks: Creating %ws directory\n"), g_usDirName.Buffer

	; Pay attention at OBJ_KERNEL_HANDLE flag. It's applicable for all object types not only for files.

	; DDK stands:
	; "Driver routines that run in a process context other than that of the system process
	; must set the OBJ_KERNEL_HANDLE attribute for the ObjectAttributes parameter of ZwCreateFile.
	; This restricts the use of the handle returned by ZwCreateFile to processes
	; running only in kernel mode. Otherwise, the handle can be accessed by the process
	; in whose context the driver is running."
	
	; But in reality even you get a handle in system process context without specifying
	; OBJ_KERNEL_HANDLE you can NOT touch this object in any other process context.
	; So better always specify OBJ_KERNEL_HANDLE if you plan access object by handle
	; in different processes. A kernel handle doesn抰 disappear until the operating system
	; shuts down and can be used without ambiguity in any process.

	InitializeObjectAttributes addr oa, addr g_usDirName, \
						OBJ_CASE_INSENSITIVE + OBJ_KERNEL_HANDLE, NULL, NULL
	invoke ZwCreateFile, addr hDirectory, SYNCHRONIZE, addr oa, addr iosb, 0, FILE_ATTRIBUTE_NORMAL, \
						0, FILE_OPEN_IF, FILE_DIRECTORY_FILE + FILE_SYNCHRONOUS_IO_NONALERT, NULL, 0
	.if eax == STATUS_SUCCESS
		.if iosb.Information == FILE_CREATED
			invoke DbgPrint, $CTA0("FileWorks: Directory created\n")
		.elseif iosb.Information == FILE_OPENED
			invoke DbgPrint, $CTA0("FileWorks: Directory exists and was opened\n")
		.endif
		invoke ZwClose, hDirectory
	.else
		invoke DbgPrint, $CTA0("FileWorks: Can't create directory. Status: %08X\n"), eax
	.endif
	
	ret

CreateDirectory endp

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;                                        CreateFile                                                 
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

CreateFile proc

local oa:OBJECT_ATTRIBUTES
local iosb:IO_STATUS_BLOCK
local hFile:HANDLE

	; Remember that the Unicode format codes (%C, %S, %lc, %ls, %wc, %ws, %wZ)
	; can only be used at IRQL PASSIVE_LEVEL. 
	invoke DbgPrint, $CTA0("\nFileWorks: Creating %ws file\n"), g_usFileName.Buffer

	InitializeObjectAttributes addr oa, addr g_usFileName, \
						OBJ_CASE_INSENSITIVE + OBJ_KERNEL_HANDLE, NULL, NULL

	; If the file already exists, fail the request and do not create or open the given file.
	; If it does not, create the given file.

	invoke ZwCreateFile, addr hFile, SYNCHRONIZE, addr oa, addr iosb, 0, FILE_ATTRIBUTE_NORMAL, \
						0, FILE_CREATE, FILE_SYNCHRONOUS_IO_NONALERT, NULL, 0
	.if eax == STATUS_SUCCESS

		invoke DbgPrint, $CTA0("FileWorks: File created\n")
		invoke ZwClose, hFile
	.else
		invoke DbgPrint, $CTA0("FileWorks: Can't create file. Status: %08X\n"), eax
	.endif
	
	ret

CreateFile endp

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;                                            WriteFile                                              
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

WriteFile proc

local oa:OBJECT_ATTRIBUTES
local iosb:IO_STATUS_BLOCK
local hFile:HANDLE

	invoke DbgPrint, $CTA0("\nFileWorks: Opening file for writing\n")

	InitializeObjectAttributes addr oa, addr g_usFileName, \
						OBJ_CASE_INSENSITIVE + OBJ_KERNEL_HANDLE, NULL, NULL
	
	; ZwCreateFile can be used for opening existing file. FILE_OPEN should be specified.
	; I use:
	; - FILE_WRITE_DATA because only I want is to write data into the file;
	; - SYNCHRONIZE because of FILE_SYNCHRONOUS_IO_NONALERT.
	; But you can simply use less strict FILE_ALL_ACCESS.

	invoke ZwCreateFile, addr hFile, FILE_WRITE_DATA + SYNCHRONIZE, addr oa, addr iosb, \
						0, 0, FILE_SHARE_READ, FILE_OPEN, FILE_SYNCHRONOUS_IO_NONALERT, NULL, 0
	.if eax == STATUS_SUCCESS
		invoke DbgPrint, $CTA0("FileWorks: File openeded\n")

		CTA0 "Data can be written to an open file", g_szData, 4

		invoke ZwWriteFile, hFile, 0, NULL, NULL, addr iosb, \
						addr g_szData, sizeof g_szData - 1, NULL, NULL
		.if eax == STATUS_SUCCESS
			invoke DbgPrint, $CTA0("FileWorks: File was written\n")
		.else
			invoke DbgPrint, $CTA0("FileWorks: Can't write to the file. Status: %08X\n"), eax
		.endif

		invoke ZwClose, hFile
	.else
		invoke DbgPrint, $CTA0("FileWorks: Can't open file. Status: %08X\n"), eax
	.endif

	ret

WriteFile endp

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;                                        MarkAsReadOnly                                             
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

MarkAsReadOnly proc

local oa:OBJECT_ATTRIBUTES
local iosb:IO_STATUS_BLOCK
local hFile:HANDLE
local fbi:FILE_BASIC_INFORMATION

	invoke DbgPrint, $CTA0("\nFileWorks: Opening file for changing attributes\n")

	InitializeObjectAttributes addr oa, addr g_usFileName, \
						OBJ_CASE_INSENSITIVE + OBJ_KERNEL_HANDLE, NULL, NULL
	
	; ZwCreateFile can be used for opening existing file. FILE_OPEN should be specified.
	; I use:
	; - FILE_READ_ATTRIBUTES because I want to query file attributes;
	; - FILE_WRITE_ATTRIBUTES because I want to change file attributes;
	; - SYNCHRONIZE because of FILE_SYNCHRONOUS_IO_NONALERT.
	; But you can simply use less strict FILE_ALL_ACCESS.

	invoke ZwCreateFile, addr hFile, FILE_READ_ATTRIBUTES + FILE_WRITE_ATTRIBUTES + SYNCHRONIZE, \
						addr oa, addr iosb, 0, 0, FILE_SHARE_READ, \
						FILE_OPEN, FILE_SYNCHRONOUS_IO_NONALERT, NULL, 0
	.if eax == STATUS_SUCCESS
		invoke DbgPrint, $CTA0("FileWorks: File openeded\n")

		; Protect the file from deletion.
		invoke ZwQueryInformationFile, hFile, addr iosb, addr fbi, sizeof fbi, FileBasicInformation
		; Undocumented ZwQueryAttributesFile does the same.
		.if eax == STATUS_SUCCESS
			invoke DbgPrint, $CTA0("FileWorks: File attributes were: %08X\n"), fbi.FileAttributes
			or fbi.FileAttributes, FILE_ATTRIBUTE_READONLY
			invoke ZwSetInformationFile, hFile, addr iosb, addr fbi, sizeof fbi, FileBasicInformation
			.if eax == STATUS_SUCCESS
				invoke DbgPrint, $CTA0("FileWorks: Now file marked as read-only\n")
			.else
				invoke DbgPrint, $CTA0("FileWorks: Can't change file attributes. Status: %08X\n"), eax
			.endif
		.else
			invoke DbgPrint, $CTA0("FileWorks: Can't query file attributes. Status: %08X\n"), eax
		.endif

		invoke ZwClose, hFile
	.else
		invoke DbgPrint, $CTA0("FileWorks: Can't open file. Status: %08X\n"), eax
	.endif

	ret

MarkAsReadOnly endp

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;                                          ReadFile                                                 
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

ReadFile proc

local oa:OBJECT_ATTRIBUTES
local iosb:IO_STATUS_BLOCK
local hFile:HANDLE
local p:PVOID
local cb:DWORD
local fsi:FILE_STANDARD_INFORMATION

	invoke DbgPrint, $CTA0("\nFileWorks: Opening file for reading\n")

	InitializeObjectAttributes addr oa, addr g_usFileName, \
						OBJ_CASE_INSENSITIVE + OBJ_KERNEL_HANDLE, NULL, NULL
	invoke ZwOpenFile, addr hFile, FILE_READ_DATA + SYNCHRONIZE, addr oa, addr iosb, \
				FILE_SHARE_READ + FILE_SHARE_WRITE + FILE_SHARE_DELETE, FILE_SYNCHRONOUS_IO_NONALERT
	.if eax == STATUS_SUCCESS

		invoke DbgPrint, $CTA0("FileWorks: File openeded\n")

		invoke ZwQueryInformationFile, hFile, addr iosb, addr fsi, sizeof fsi, FileStandardInformation
		.if eax == STATUS_SUCCESS

			mov eax, fsi.EndOfFile.LowPart
			inc eax								; one byte more for terminating zero
			mov cb, eax

			invoke ExAllocatePool, PagedPool, cb
			.if eax != NULL
				mov p, eax

				invoke RtlZeroMemory, p, cb

				invoke ZwReadFile, hFile, 0, NULL, NULL, addr iosb, p, cb, 0, NULL
				.if eax == STATUS_SUCCESS
					invoke DbgPrint, $CTA0("FileWorks: File content: \=%s\=\n"), p
				.else
					invoke DbgPrint, $CTA0("FileWorks: Can't read from the file. Status: %08X\n"), eax
				.endif

				invoke ExFreePool, p

			.else
				invoke DbgPrint, $CTA0("FileWorks: Can't allocate memory. Status: %08X\n"), eax
			.endif
		.else
			invoke DbgPrint, $CTA0("FileWorks: Can't query file size. Status: %08X\n"), eax
		.endif

		invoke ZwClose, hFile

	.else
		invoke DbgPrint, $CTA0("FileWorks: Can't open file. Status: %08X\n"), eax
	.endif

	ret

ReadFile endp

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;                                        UnmarkAsReadOnly                                           
;:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

UnmarkAsReadOnly proc

local oa:OBJECT_ATTRIBUTES
local iosb:IO_STATUS_BLOCK
local hFile:HANDLE
local fbi:FILE_BASIC_INFORMATION

	invoke DbgPrint, $CTA0("\nFileWorks: Opening file for changing attributes\n")

	InitializeObjectAttributes addr oa, addr g_usFileName, \
						OBJ_CASE_INSENSITIVE + OBJ_KERNEL_HANDLE, NULL, NULL
	
	; ZwCreateFile can be used for opening existing file. FILE_OPEN should be specified.
	; I use:
	; - FILE_READ_ATTRIBUTES because I want to query file attributes;
	; - FILE_WRITE_ATTRIBUTES because I want to change file attributes;
	; - SYNCHRONIZE because of FILE_SYNCHRONOUS_IO_NONALERT.
	; But you can simply use less strict FILE_ALL_ACCESS.

	invoke ZwCreateFile, addr hFile, FILE_READ_ATTRIBUTES + FILE_WRITE_ATTRIBUTES + SYNCHRONIZE, \
						addr oa, addr iosb, 0, 0, FILE_SHARE_READ, FILE_OPEN, \
						FILE_SYNCHRONOUS_IO_NONALERT, NULL, 0
	.if eax == STATUS_SUCCESS
		invoke DbgPrint, $CTA0("FileWorks: File openeded\n")

		; Allow delete file.
		invoke ZwQueryInformationFile, hFile, addr iosb, addr fbi, sizeof fbi, FileBasicInformation
		; Undocumented ZwQueryAttributesFile does the same.
		.if eax == STATUS_SUCCESS
			invoke DbgPrint, $CTA0("FileWorks: File attributes were: %08X\n"), fbi.FileAttributes
			and fbi.FileAttributes, not FILE_ATTRIBUTE_READONLY
			invoke ZwSetInformationFile, hFile, addr iosb, addr fbi, sizeof fbi, FileBasicInformation
			.if eax == STATUS_SUCCESS
				invoke DbgPrint, $CTA0("FileWorks: Now file can be written or deleted\n")
			.else
				invoke DbgPrint, $CTA0("FileWorks: Can't change file attributes. Status: %08X\n"), eax
			.endif
		.else
			invoke DbgPrint, $CTA0("FileWorks: Can't query file attributes. Status: %08X\n"), eax
		.endif

		invoke ZwClose, hFile
	.else
		invoke DbgPrint, $CTA0("FileWorks: Can't open file. Status: %08X\n"), eax
	.endif

	ret

UnmarkAsReadOnly endp