[EDIT:]
这个问题很难解决,至少通过修改MFT是不可行的,因为NTFS MFT结构本身并不完全“开放”,所以我开始涉足逆向工程领域,这将带来法律后果,而我不想处理。此外,在.NET中进行此操作是一项超级繁琐的过程,需要基于许多猜测来映射和调用结构(更不用说大多数MFT结构以奇怪的方式压缩了)。简而言之,虽然我确实学到了关于NTFS“工作”的很多知识,但我离解决这个问题还有很长的路要走。
[/EDIT]
呃......太多的调用和调度了....
这引起了我的注意,因此我被迫探究这个问题...这仍然是一个“正在进行中的答案”,但我想发布我所拥有的所有内容,以帮助其他人得出一些结论。 :)
此外,我大致感觉在FAT32上会容易得多,但考虑到我只有NTFS可以使用...
所以 - 很多pinvoking和marshalling,让我们从那里开始并向后工作:
正如人们可能猜到的那样,标准的.NET文件/IO API在这里无法帮助你太多 - 我们需要设备级别的访问:
[DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
static extern SafeFileHandle CreateFile(
string lpFileName,
[MarshalAs(UnmanagedType.U4)] FileAccess dwDesiredAccess,
[MarshalAs(UnmanagedType.U4)] FileShare dwShareMode,
IntPtr lpSecurityAttributes,
[MarshalAs(UnmanagedType.U4)] FileMode dwCreationDisposition,
[MarshalAs(UnmanagedType.U4)] FileAttributes dwFlagsAndAttributes,
IntPtr hTemplateFile);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
public static extern bool ReadFile(
SafeFileHandle hFile, // handle to file
byte[] pBuffer, // data buffer, should be fixed
int NumberOfBytesToRead, // number of bytes to read
IntPtr pNumberOfBytesRead, // number of bytes read, provide NULL here
ref NativeOverlapped lpOverlapped // should be fixed, if not null
);
[DllImport("Kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
public static extern bool SetFilePointerEx(
SafeFileHandle hFile,
long liDistanceToMove,
out long lpNewFilePointer,
SeekOrigin dwMoveMethod);
我们将这些令人讨厌的win32野兽用于以下方式:
using (var fileHandle = NativeMethods.CreateFile(
@"\\.\c:",
FileAccess.Read | FileAccess.Write,
FileShare.Write | FileShare.Read,
IntPtr.Zero,
FileMode.Open,
FileAttributes.Normal,
IntPtr.Zero))
{
if (fileHandle.IsInvalid)
{
throw new Win32Exception();
}
else
{
byte[] buffer = new byte[512];
NativeOverlapped overlapped = new NativeOverlapped();
NativeMethods.ReadFile(fileHandle, buffer, buffer.Length, IntPtr.Zero, ref overlapped);
var handle = GCHandle.Alloc(buffer, GCHandleType.Pinned);
try
{
var bootSector = (BootSector_NTFS)Marshal.PtrToStructure(
handle.AddrOfPinnedObject(),
typeof(BootSector_NTFS));
哇,哇哇哇 - 什么是 BootSector_NTFS
?它是一个字节映射的 struct
,据我所知,它最接近 NTFS 结构(也包括 FAT32):
[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi, Pack=0)]
public struct JumpBoot
{
[MarshalAs(UnmanagedType.ByValArray, ArraySubType=UnmanagedType.U1, SizeConst=3)]
public byte[] BS_jmpBoot;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst=8)]
public string BS_OEMName;
}
[StructLayout(LayoutKind.Explicit, CharSet = CharSet.Ansi, Pack = 0, Size = 90)]
public struct BootSector_NTFS
{
[FieldOffset(0)]
public JumpBoot JumpBoot;
[FieldOffset(0xb)]
public short BytesPerSector;
[FieldOffset(0xd)]
public byte SectorsPerCluster;
[FieldOffset(0xe)]
public short ReservedSectorCount;
[FieldOffset(0x10)]
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 5)]
public byte[] Reserved0_MUSTBEZEROs;
[FieldOffset(0x15)]
public byte BPB_Media;
[FieldOffset(0x16)]
public short Reserved1_MUSTBEZERO;
[FieldOffset(0x18)]
public short SectorsPerTrack;
[FieldOffset(0x1A)]
public short HeadCount;
[FieldOffset(0x1c)]
public int HiddenSectorCount;
[FieldOffset(0x20)]
public int LargeSectors;
[FieldOffset(0x24)]
public int Reserved6;
[FieldOffset(0x28)]
public long TotalSectors;
[FieldOffset(0x30)]
public long MftClusterNumber;
[FieldOffset(0x38)]
public long MftMirrorClusterNumber;
[FieldOffset(0x40)]
public byte ClustersPerMftRecord;
[FieldOffset(0x41)]
public byte Reserved7;
[FieldOffset(0x42)]
public short Reserved8;
[FieldOffset(0x44)]
public byte ClustersPerIndexBuffer;
[FieldOffset(0x45)]
public byte Reserved9;
[FieldOffset(0x46)]
public short ReservedA;
[FieldOffset(0x48)]
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
public byte[] SerialNumber;
[FieldOffset(0x50)]
public int Checksum;
[FieldOffset(0x54)]
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 0x1AA)]
public byte[] BootupCode;
[FieldOffset(0x1FE)]
public ushort EndOfSectorMarker;
public long GetMftAbsoluteIndex(int recordIndex = 0)
{
return (BytesPerSector * SectorsPerCluster * MftClusterNumber) + (GetMftEntrySize() * recordIndex);
}
public long GetMftEntrySize()
{
return (BytesPerSector * SectorsPerCluster * ClustersPerMftRecord);
}
}
[StructLayout(LayoutKind.Explicit, CharSet=CharSet.Auto, Pack=0, Size=90)]
public struct BootSector_FAT32
{
[FieldOffset(0)]
public JumpBoot JumpBoot;
[FieldOffset(11)]
public short BPB_BytsPerSec;
[FieldOffset(13)]
public byte BPB_SecPerClus;
[FieldOffset(14)]
public short BPB_RsvdSecCnt;
[FieldOffset(16)]
public byte BPB_NumFATs;
[FieldOffset(17)]
public short BPB_RootEntCnt;
[FieldOffset(19)]
public short BPB_TotSec16;
[FieldOffset(21)]
public byte BPB_Media;
[FieldOffset(22)]
public short BPB_FATSz16;
[FieldOffset(24)]
public short BPB_SecPerTrk;
[FieldOffset(26)]
public short BPB_NumHeads;
[FieldOffset(28)]
public int BPB_HiddSec;
[FieldOffset(32)]
public int BPB_TotSec32;
[FieldOffset(36)]
public FAT32 FAT;
}
[StructLayout(LayoutKind.Sequential)]
public struct FAT32
{
public int BPB_FATSz32;
public short BPB_ExtFlags;
public short BPB_FSVer;
public int BPB_RootClus;
public short BPB_FSInfo;
public short BPB_BkBootSec;
[MarshalAs(UnmanagedType.ByValArray, SizeConst=12)]
public byte[] BPB_Reserved;
public byte BS_DrvNum;
public byte BS_Reserved1;
public byte BS_BootSig;
public int BS_VolID;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst=11)]
public string BS_VolLab;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst=8)]
public string BS_FilSysType;
}
现在我们可以将一大堆乱码映射回到这个结构中:
// Pin it so we can transmogrify it into a FAT structure
var handle = GCHandle.Alloc(buffer, GCHandleType.Pinned);
try
{
// note, I've got an NTFS drive, change yours to suit
var bootSector = (BootSector_NTFS)Marshal.PtrToStructure(
handle.AddrOfPinnedObject(),
typeof(BootSector_NTFS));
Console.WriteLine(
"I think that the Master File Table is at absolute position:{0}, sector:{1}",
bootSector.GetMftAbsoluteIndex(),
bootSector.GetMftAbsoluteIndex() / bootSector.BytesPerSector);
此时输出如下:
I think that the Master File Table is at
absolute position:3221225472, sector:6291456
让我们使用原始设备制造商支持工具nfi.exe
来快速确认:
C:\tools\OEMTools\nfi>nfi c:
NTFS File Sector Information Utility.
Copyright (C) Microsoft Corporation 1999. All rights reserved.
File 0
Master File Table ($Mft)
$STANDARD_INFORMATION (resident)
$FILE_NAME (resident)
$DATA (nonresident)
logical sectors 6291456-6487039 (0x600000-0x62fbff)
logical sectors 366267960-369153591 (0x15d4ce38-0x1600d637)
$BITMAP (nonresident)
logical sectors 6291448-6291455 (0x5ffff8-0x5fffff)
logical sectors 7273984-7274367 (0x6efe00-0x6eff7f)
酷,看起来我们在正确的轨道上...继续前进!
bootSector.Dump();
Console.WriteLine("Jumping to Master File Table...");
long lpNewFilePointer;
if (!NativeMethods.SetFilePointerEx(
fileHandle,
bootSector.GetMftAbsoluteIndex(),
out lpNewFilePointer,
SeekOrigin.Begin))
{
throw new Win32Exception();
}
Console.WriteLine("Position now: {0}", lpNewFilePointer);
byte[] mft_buffer = new byte[bootSector.GetMftEntrySize()];
Console.WriteLine("Reading $MFT entry...calculated size: 0x{0}",
bootSector.GetMftEntrySize().ToString("X"));
var seekIndex = bootSector.GetMftAbsoluteIndex();
overlapped.OffsetHigh = (int)(seekIndex >> 32);
overlapped.OffsetLow = (int)seekIndex;
NativeMethods.ReadFile(
fileHandle,
mft_buffer,
mft_buffer.Length,
IntPtr.Zero,
ref overlapped);
var mft_handle = GCHandle.Alloc(mft_buffer, GCHandleType.Pinned);
try
{
var mftRecords = (MFTSystemRecords)Marshal.PtrToStructure(
mft_handle.AddrOfPinnedObject(),
typeof(MFTSystemRecords));
mftRecords.Dump();
}
finally
{
mft_handle.Free();
}
}
finally
{
handle.Free();
}
啊,还有更多的本地结构需要讨论 - 因此MFT的排列是这样的,前16个或左右的条目是“固定”的:
[StructLayout(LayoutKind.Sequential)]
public struct MFTSystemRecords
{
public MFTRecord Mft;
public MFTRecord MftMirror;
public MFTRecord LogFile;
public MFTRecord Volume;
public MFTRecord AttributeDefs;
public MFTRecord RootFile;
public MFTRecord ClusterBitmap;
public MFTRecord BootSector;
public MFTRecord BadClusterFile;
public MFTRecord SecurityFile;
public MFTRecord UpcaseTable;
public MFTRecord ExtensionFile;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 16)]
public MFTRecord[] MftReserved;
public MFTRecord MftFileExt;
}
这里的MFTRecord
是:
[StructLayout(LayoutKind.Sequential, Size = 1024)]
public struct MFTRecord
{
const int BASE_RECORD_SIZE = 48;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 4)]
public string Type;
public short UsaOffset;
public short UsaCount;
public long Lsn;
public short SequenceNumber;
public short LinkCount;
public short AttributeOffset;
public short MftRecordFlags;
public int BytesInUse;
public int BytesAllocated;
public long BaseFileRecord;
public short NextAttributeNumber;
public short Reserved;
public int MftRecordNumber;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 976)]
public byte[] Data;
public byte[] SetData
{
get
{
return this.Data
.Skip(AttributeOffset - BASE_RECORD_SIZE)
.Take(BytesInUse - BASE_RECORD_SIZE)
.ToArray();
}
}
public MftAttribute[] Attributes
{
get
{
var idx = 0;
var ret = new List<MftAttribute>();
while (idx < SetData.Length)
{
var attr = MftAttribute.FromBytes(SetData.Skip(idx).ToArray());
ret.Add(attr);
idx += attr.Attribute.Length;
if (attr.Attribute.AttributeType == MftAttributeType.AT_END) break;
}
return ret.ToArray();
}
}
}
这里是我的限制,我得去吃晚饭之类的原因所在。但是我会回来的!
参考文献(部分为了自己记忆,部分为了协助其他调查人员):
以下是完整的代码转储:
上面我略过的所有本地映射(由于帖子大小限制而不是全面回顾):
public enum MftRecordFlags : ushort
{
MFT_RECORD_IN_USE = 0x0001,
MFT_RECORD_IS_DIRECTORY = 0x0002,
MFT_RECORD_IN_EXTEND = 0x0004,
MFT_RECORD_IS_VIEW_INDEX = 0x0008,
MFT_REC_SPACE_FILLER = 0xffff
}
public enum MftAttributeType : uint
{
AT_UNUSED = 0,
AT_STANDARD_INFORMATION = 0x10,
AT_ATTRIBUTE_LIST = 0x20,
AT_FILENAME = 0x30,
AT_OBJECT_ID = 0x40,
AT_SECURITY_DESCRIPTOR = 0x50,
AT_VOLUME_NAME = 0x60,
AT_VOLUME_INFORMATION = 0x70,
AT_DATA = 0x80,
AT_INDEX_ROOT = 0x90,
AT_INDEX_ALLOCATION = 0xa0,
AT_BITMAP = 0xb0,
AT_REPARSE_POINT = 0xc0,
AT_EA_INFORMATION = 0xd0,
AT_EA = 0xe0,
AT_PROPERTY_SET = 0xf0,
AT_LOGGED_UTILITY_STREAM = 0x100,
AT_FIRST_USER_DEFINED_ATTRIBUTE = 0x1000,
AT_END = 0xffffffff
}
public enum MftAttributeDefFlags : byte
{
ATTR_DEF_INDEXABLE = 0x02,
ATTR_DEF_MULTIPLE = 0x04,
ATTR_DEF_NOT_ZERO = 0x08,
ATTR_DEF_INDEXED_UNIQUE = 0x10,
ATTR_DEF_NAMED_UNIQUE = 0x20,
ATTR_DEF_RESIDENT = 0x40,
ATTR_DEF_ALWAYS_LOG = 0x80,
}
[StructLayout(LayoutKind.Explicit)]
public struct MftInternalAttribute
{
[FieldOffset(0)]
public MftAttributeType AttributeType;
[FieldOffset(4)]
public int Length;
[FieldOffset(8)]
[MarshalAs(UnmanagedType.Bool)]
public bool NonResident;
[FieldOffset(9)]
public byte NameLength;
[FieldOffset(10)]
public short NameOffset;
[FieldOffset(12)]
public int AttributeFlags;
[FieldOffset(14)]
public short Instance;
[FieldOffset(16)]
public ResidentAttribute ResidentAttribute;
[FieldOffset(16)]
public NonResidentAttribute NonResidentAttribute;
}
[StructLayout(LayoutKind.Sequential)]
public struct ResidentAttribute
{
public int ValueLength;
public short ValueOffset;
public byte ResidentAttributeFlags;
public byte Reserved;
public override string ToString()
{
return string.Format("{0}:{1}:{2}:{3}", ValueLength, ValueOffset, ResidentAttributeFlags, Reserved);
}
}
[StructLayout(LayoutKind.Sequential)]
public struct NonResidentAttribute
{
public long LowestVcn;
public long HighestVcn;
public short MappingPairsOffset;
public byte CompressionUnit;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 5)]
public byte[] Reserved;
public long AllocatedSize;
public long DataSize;
public long InitializedSize;
public long CompressedSize;
public override string ToString()
{
return string.Format("{0}:{1}:{2}:{3}:{4}:{5}:{6}:{7}", LowestVcn, HighestVcn, MappingPairsOffset, CompressionUnit, AllocatedSize, DataSize, InitializedSize, CompressedSize);
}
}
public struct MftAttribute
{
public MftInternalAttribute Attribute;
[field: NonSerialized]
public string Name;
[field: NonSerialized]
public byte[] Data;
[field: NonSerialized]
public object Payload;
public static MftAttribute FromBytes(byte[] buffer)
{
var hnd = GCHandle.Alloc(buffer, GCHandleType.Pinned);
try
{
var attr = (MftInternalAttribute)Marshal.PtrToStructure(hnd.AddrOfPinnedObject(), typeof(MftInternalAttribute));
var ret = new MftAttribute() { Attribute = attr };
ret.Data = buffer.Skip(Marshal.SizeOf(attr)).Take(attr.Length).ToArray();
if (ret.Attribute.AttributeType == MftAttributeType.AT_STANDARD_INFORMATION)
{
var payloadHnd = GCHandle.Alloc(ret.Data, GCHandleType.Pinned);
try
{
var payload = (MftStandardInformation)Marshal.PtrToStructure(payloadHnd.AddrOfPinnedObject(), typeof(MftStandardInformation));
ret.Payload = payload;
}
finally
{
payloadHnd.Free();
}
}
return ret;
}
finally
{
hnd.Free();
}
}
}
[StructLayout(LayoutKind.Sequential)]
public struct MftStandardInformation
{
public ulong CreationTime;
public ulong LastDataChangeTime;
public ulong LastMftChangeTime;
public ulong LastAccessTime;
public int FileAttributes;
public int MaximumVersions;
public int VersionNumber;
public int ClassId;
public int OwnerId;
public int SecurityId;
public long QuotaChanged;
public long Usn;
}
[StructLayout(LayoutKind.Explicit, CharSet = CharSet.Auto, Pack = 0, Size = 90)]
public struct BootSector_FAT32
{
[FieldOffset(0)]
public JumpBoot JumpBoot;
[FieldOffset(11)]
public short BPB_BytsPerSec;
[FieldOffset(13)]
public byte BPB_SecPerClus;
[FieldOffset(14)]
public short BPB_RsvdSecCnt;
[FieldOffset(16)]
public byte BPB_NumFATs;
[FieldOffset(17)]
public short BPB_RootEntCnt;
[FieldOffset(19)]
public short BPB_TotSec16;
[FieldOffset(21)]
public byte BPB_Media;
[FieldOffset(22)]
public short BPB_FATSz16;
[FieldOffset(24)]
public short BPB_SecPerTrk;
[FieldOffset(26)]
public short BPB_NumHeads;
[FieldOffset(28)]
public int BPB_HiddSec;
[FieldOffset(32)]
public int BPB_TotSec32;
[FieldOffset(36)]
public FAT32 FAT;
}
[StructLayout(LayoutKind.Sequential)]
public struct FAT32
{
public int BPB_FATSz32;
public short BPB_ExtFlags;
public short BPB_FSVer;
public int BPB_RootClus;
public short BPB_FSInfo;
public short BPB_BkBootSec;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 12)]
public byte[] BPB_Reserved;
public byte BS_DrvNum;
public byte BS_Reserved1;
public byte BS_BootSig;
public int BS_VolID;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 11)]
public string BS_VolLab;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 8)]
public string BS_FilSysType;
}
还有测试工具:
class Program
{
static void Main(string[] args)
{
using (var fileHandle = NativeMethods.CreateFile(
@"\\.\c:",
FileAccess.Read | FileAccess.Write,
FileShare.Write | FileShare.Read,
IntPtr.Zero,
FileMode.Open,
FileAttributes.Normal,
IntPtr.Zero))
{
if (fileHandle.IsInvalid)
{
throw new Win32Exception();
}
else
{
byte[] buffer = new byte[512];
NativeOverlapped overlapped = new NativeOverlapped();
NativeMethods.ReadFile(fileHandle, buffer, buffer.Length, IntPtr.Zero, ref overlapped);
var handle = GCHandle.Alloc(buffer, GCHandleType.Pinned);
try
{
var bootSector = (BootSector_NTFS)Marshal.PtrToStructure(handle.AddrOfPinnedObject(), typeof(BootSector_NTFS));
Console.WriteLine(
"I think that the Master File Table is at absolute position:{0}, sector:{1}",
bootSector.GetMftAbsoluteIndex(),
bootSector.GetMftAbsoluteIndex() / bootSector.BytesPerSector);
Console.WriteLine("MFT record size:{0}", bootSector.ClustersPerMftRecord * bootSector.SectorsPerCluster * bootSector.BytesPerSector);
bootSector.DumpToHtmlString();
Pause();
Console.WriteLine("Jumping to Master File Table...");
long lpNewFilePointer;
if (!NativeMethods.SetFilePointerEx(fileHandle, bootSector.GetMftAbsoluteIndex(), out lpNewFilePointer, SeekOrigin.Begin))
{
throw new Win32Exception();
}
Console.WriteLine("Position now: {0}", lpNewFilePointer);
byte[] mft_buffer = new byte[bootSector.GetMftEntrySize()];
Console.WriteLine("Reading $MFT entry...calculated size: 0x{0}", bootSector.GetMftEntrySize().ToString("X"));
var seekIndex = bootSector.GetMftAbsoluteIndex();
overlapped.OffsetHigh = (int)(seekIndex >> 32);
overlapped.OffsetLow = (int)seekIndex;
NativeMethods.ReadFile(fileHandle, mft_buffer, mft_buffer.Length, IntPtr.Zero, ref overlapped);
var mft_handle = GCHandle.Alloc(mft_buffer, GCHandleType.Pinned);
try
{
var mftRecords = (MFTSystemRecords)Marshal.PtrToStructure(mft_handle.AddrOfPinnedObject(), typeof(MFTSystemRecords));
mftRecords.DumpToHtmlString();
}
finally
{
mft_handle.Free();
}
}
finally
{
handle.Free();
}
}
}
Pause();
}
private static void Pause()
{
Console.WriteLine("Press enter to continue...");
Console.ReadLine();
}
}
public static class Dumper
{
public static string DumpToHtmlString<T>(this T objectToSerialize)
{
string strHTML = "";
try
{
var writer = LINQPad.Util.CreateXhtmlWriter(true);
writer.Write(objectToSerialize);
strHTML = writer.ToString();
}
catch (Exception exc)
{
Debug.Assert(false, "Investigate why ?" + exc);
}
var shower = new Thread(
() =>
{
var dumpWin = new Window();
var browser = new WebBrowser();
dumpWin.Content = browser;
browser.NavigateToString(strHTML);
dumpWin.ShowDialog();
});
shower.SetApartmentState(ApartmentState.STA);
shower.Start();
return strHTML;
}
public static string Dump(this object value)
{
return JsonConvert.SerializeObject(value, Formatting.Indented);
}
}