public ulong[] VerifyDataHashTree(bool rehash = false)
{
ulong dataBlockCount = XvdMath.OffsetToPageNumber((ulong)_io.Stream.Length - UserDataOffset);
var invalidBlocks = new List <ulong>();
for (ulong i = 0; i < dataBlockCount; i++)
{
var hashEntryOffset = CalculateHashEntryOffsetForBlock(i, 0);
_io.Stream.Position = (long)hashEntryOffset;
byte[] oldhash = _io.Reader.ReadBytes((int)DataHashEntryLength);
var dataToHashOffset = XvdMath.PageNumberToOffset(i) + UserDataOffset;
_io.Stream.Position = (long)dataToHashOffset;
byte[] data = _io.Reader.ReadBytes((int)PAGE_SIZE);
byte[] hash = HashUtils.ComputeSha256(data);
Array.Resize(ref hash, (int)DataHashEntryLength);
if (hash.IsEqualTo(oldhash))
{
continue;
}
invalidBlocks.Add(i);
if (!rehash)
{
continue;
}
_io.Stream.Position = (long)hashEntryOffset;
_io.Writer.Write(hash);
}
return(invalidBlocks.ToArray());
}
public bool VirtualToLogicalDriveOffset(ulong virtualOffset, out ulong logicalOffset)
{
logicalOffset = 0;
if (virtualOffset >= Header.DriveSize)
{
throw new InvalidOperationException(
$"Virtual offset 0x{virtualOffset:X} is outside drivedata length 0x{Header.DriveSize:X}");
}
if (Header.Type > XvdType.Dynamic)
{
throw new NotSupportedException($"Xvd type {Header.Type} is unhandled");
}
if (Header.Type == XvdType.Dynamic)
{
var dataStartOffset = virtualOffset + XvdMath.PageNumberToOffset(Header.NumberOfMetadataPages);
var pageNumber = XvdMath.OffsetToPageNumber(dataStartOffset);
var inBlockOffset = XvdMath.InBlockOffset(dataStartOffset);
var firstDynamicPage = XvdMath.QueryFirstDynamicPage(Header.NumberOfMetadataPages);
if (pageNumber >= firstDynamicPage)
{
var firstDynamicPageBytes = XvdMath.PageNumberToOffset(firstDynamicPage);
var blockNumber = XvdMath.OffsetToBlockNumber(dataStartOffset - firstDynamicPageBytes);
ulong allocatedBlock = ReadBat(blockNumber);
if (allocatedBlock == INVALID_SECTOR)
{
return(false);
}
dataStartOffset = XvdMath.PageNumberToOffset(allocatedBlock) + inBlockOffset;
pageNumber = XvdMath.OffsetToPageNumber(dataStartOffset);
}
var dataBackingBlockNum = XvdMath.ComputeDataBackingPageNumber(Header.Type,
HashTreeLevels,
HashTreePageCount,
pageNumber);
logicalOffset = XvdMath.PageNumberToOffset(dataBackingBlockNum);
logicalOffset += XvdMath.InPageOffset(dataStartOffset);
logicalOffset += XvdMath.PageNumberToOffset(Header.EmbeddedXvdPageCount);
logicalOffset += Header.MutableDataLength;
logicalOffset += XVD_HEADER_INCL_SIGNATURE_SIZE;
logicalOffset += PAGE_SIZE;
}
else
{ // Xvd type fixed
logicalOffset = virtualOffset;
logicalOffset += XvdMath.PageNumberToOffset(Header.EmbeddedXvdPageCount);
logicalOffset += Header.MutableDataLength;
logicalOffset += XvdMath.PageNumberToOffset(Header.NumberOfMetadataPages);
logicalOffset += XVD_HEADER_INCL_SIGNATURE_SIZE;
logicalOffset += PAGE_SIZE;
}
return(true);
}
public bool VerifyHashTree()
{
if (!IsDataIntegrityEnabled)
{
return(true);
}
_io.Stream.Position = (long)HashTreeOffset;
byte[] hash = HashUtils.ComputeSha256(_io.Reader.ReadBytes((int)PAGE_SIZE));
if (!Header.TopHashBlockHash.IsEqualTo(hash))
{
return(false);
}
if (HashTreeLevels == 1)
{
return(true);
}
var blocksPerLevel = 0xAA;
ulong topHashTreeBlock = 0;
uint hashTreeLevel = 1;
while (hashTreeLevel < HashTreeLevels)
{
uint dataBlockNum = 0;
if (Header.NumberOfHashedPages != 0)
{
while (dataBlockNum < Header.NumberOfHashedPages)
{
_io.Stream.Position = (long)CalculateHashEntryOffsetForBlock(dataBlockNum, hashTreeLevel - 1);
byte[] blockHash = HashUtils.ComputeSha256(_io.Reader.ReadBytes((int)PAGE_SIZE));
Array.Resize(ref blockHash, (int)HASH_ENTRY_LENGTH);
var upperHashBlockOffset = CalculateHashEntryOffsetForBlock(dataBlockNum, hashTreeLevel);
topHashTreeBlock = XvdMath.OffsetToPageNumber(upperHashBlockOffset - HashTreeOffset);
_io.Stream.Position = (long)upperHashBlockOffset;
byte[] expectedHash = _io.Reader.ReadBytes((int)HASH_ENTRY_LENGTH);
if (!expectedHash.IsEqualTo(blockHash))
{
// wrong hash
return(false);
}
dataBlockNum += (uint)blocksPerLevel;
}
}
hashTreeLevel++;
blocksPerLevel = blocksPerLevel * 0xAA;
}
if (topHashTreeBlock != 0)
{
Console.WriteLine(@"Top level hash page calculated to be at {0}, should be 0!", topHashTreeBlock);
}
return(true);
}
internal bool RemoveData(ulong offset, ulong numPages)
{
var page = XvdMath.OffsetToPageNumber(offset);
var length = numPages * PAGE_SIZE;
_io.Stream.Position = (long)offset;
if (!_io.DeleteBytes((long)length))
{
return(false);
}
if (!IsXvcFile)
{
return(true);
}
if (XvcInfo.InitialPlayOffset > offset)
{
XvcInfo.InitialPlayOffset -= length;
}
if (XvcInfo.PreviewOffset > offset)
{
XvcInfo.PreviewOffset -= length;
}
for (int i = 0; i < RegionHeaders.Count; i++)
{
var region = RegionHeaders[i];
region.Hash = 0; // ???
if (offset >= region.Offset && region.Offset + region.Length > offset)
{
region.Length -= length; // offset is part of region, reduce length
}
else if (region.Offset > offset)
{
region.Offset -= length; // offset is before region, reduce offset
}
RegionHeaders[i] = region; // region is a copy instead of a reference due to it being a struct, so we have to replace the original data ourselves
}
for (int i = 0; i < UpdateSegments.Count; i++)
{
var segment = UpdateSegments[i];
if (segment.PageNum < page)
{
continue;
}
segment.PageNum -= (uint)numPages;
UpdateSegments[i] = segment;
}
return(true);
}
internal bool AddData(ulong offset, ulong numPages)
{
var page = XvdMath.OffsetToPageNumber(offset);
var length = numPages * PAGE_SIZE;
_io.Stream.Position = (long)offset;
if (!_io.AddBytes((long)length))
{
return(false);
}
if (!IsXvcFile)
{
return(true);
}
if (XvcInfo.InitialPlayOffset > offset)
{
XvcInfo.InitialPlayOffset += length;
}
if (XvcInfo.PreviewOffset > offset)
{
XvcInfo.PreviewOffset += length;
}
for (int i = 0; i < RegionHeaders.Count; i++)
{
var region = RegionHeaders[i];
region.Hash = 0; // ???
if (offset >= region.Offset && region.Offset + region.Length > offset)
{
region.Length += length; // offset is part of region, add to length
}
else if (region.Offset > offset)
{
region.Offset += length; // offset is before region, add to offset
}
RegionHeaders[i] = region;
}
for (int i = 0; i < UpdateSegments.Count; i++)
{
var segment = UpdateSegments[i];
if (segment.PageNum < page)
{
continue;
}
segment.PageNum += (uint)numPages;
UpdateSegments[i] = segment;
}
return(true);
}
internal bool CryptSectionXts(bool encrypt, byte[] key, uint headerId, ulong offset, ulong length)
{
var startPage = XvdMath.OffsetToPageNumber(offset - UserDataOffset);
ulong numPages = XvdMath.BytesToPages(length);
// Pre-read data unit numbers to minimize needing to seek around the file
List <uint> dataUnits = null;
if (IsDataIntegrityEnabled)
{
dataUnits = new List <uint>();
for (uint page = 0; page < numPages; page++)
{
// fetch dataUnit from hash table entry for this page
// TODO: seems we'll have to insert dataUnit when re-adding hashtables...
// last 4 bytes of hash entry = dataUnit
_io.Stream.Position = (long)CalculateHashEntryOffsetForBlock(startPage + page, 0) + 0x14;
dataUnits.Add(_io.Reader.ReadUInt32());
}
}
var tweakAesKey = new byte[0x10];
var dataAesKey = new byte[0x10];
var tweak = new byte[0x10];
// Split tweak- / Data AES key
Array.Copy(key, tweakAesKey, 0x10);
Array.Copy(key, 0x10, dataAesKey, 0, 0x10);
// Copy VDUID and header Id as tweak
var headerIdBytes = BitConverter.GetBytes(headerId);
Array.Copy(Header.VDUID, 0, tweak, 0x8, 0x8);
Array.Copy(headerIdBytes, 0, tweak, 0x4, 0x4);
var cipher = new AesXtsTransform(tweak, dataAesKey, tweakAesKey, encrypt);
// Perform crypto!
_io.Stream.Position = (long)offset;
for (uint page = 0; page < numPages; page++)
{
var transformedData = new byte[PAGE_SIZE];
var pageOffset = _io.Stream.Position;
var origData = _io.Reader.ReadBytes((int)PAGE_SIZE);
cipher.TransformDataUnit(origData, 0, origData.Length, transformedData, 0, dataUnits?[(int)page] ?? page);
_io.Stream.Position = pageOffset;
_io.Writer.Write(transformedData);
}
return(true);
}
