public AesXtsFile(OpenMode mode, IFile baseFile, U8String path, ReadOnlySpan <byte> kekSeed, ReadOnlySpan <byte> verificationKey, int blockSize)
{
Mode = mode;
BaseFile = baseFile;
Path = path;
KekSeed = kekSeed.ToArray();
VerificationKey = verificationKey.ToArray();
BlockSize = blockSize;
Header = new AesXtsFileHeader(BaseFile);
baseFile.GetSize(out long fileSize).ThrowIfFailure();
if (!Header.TryDecryptHeader(Path.ToString(), KekSeed, VerificationKey))
{
ThrowHelper.ThrowResult(ResultFs.AesXtsFileHeaderInvalidKeys.Value, "NAX0 key derivation failed.");
}
if (HeaderLength + Utilities.AlignUp(Header.Size, 0x10) > fileSize)
{
ThrowHelper.ThrowResult(ResultFs.AesXtsFileTooShort.Value, "NAX0 key derivation failed.");
}
var fileStorage = new FileStorage2(baseFile);
var encStorage = new SubStorage(fileStorage, HeaderLength, fileSize - HeaderLength);
encStorage.SetResizable(true);
BaseStorage = new CachedStorage(new Aes128XtsStorage(encStorage, Header.DecryptedKey1, Header.DecryptedKey2, BlockSize, true), 4, true);
}
public AesXtsFile(OpenMode mode, IFile baseFile, string path, ReadOnlySpan <byte> kekSeed, ReadOnlySpan <byte> verificationKey, int blockSize)
{
Mode = mode;
BaseFile = baseFile;
Path = path;
KekSeed = kekSeed.ToArray();
VerificationKey = verificationKey.ToArray();
BlockSize = blockSize;
Header = new AesXtsFileHeader(BaseFile);
baseFile.GetSize(out long fileSize).ThrowIfFailure();
if (!Header.TryDecryptHeader(Path, KekSeed, VerificationKey))
{
ThrowHelper.ThrowResult(ResultFs.AesXtsFileHeaderInvalidKeys, "NAX0 key derivation failed.");
}
if (HeaderLength + Util.AlignUp(Header.Size, 0x10) > fileSize)
{
ThrowHelper.ThrowResult(ResultFs.AesXtsFileTooShort, "NAX0 key derivation failed.");
}
IStorage encStorage = BaseFile.AsStorage().Slice(HeaderLength, Util.AlignUp(Header.Size, 0x10));
BaseStorage = new CachedStorage(new Aes128XtsStorage(encStorage, Header.DecryptedKey1, Header.DecryptedKey2, BlockSize, true), 4, true);
}
private bool TryReadXtsHeader(string filePath, string keyPath, out AesXtsFileHeader header)
{
Debug.Assert(PathTools.IsNormalized(filePath.AsSpan()));
Debug.Assert(PathTools.IsNormalized(keyPath.AsSpan()));
header = null;
Result rc = BaseFileSystem.OpenFile(out IFile file, filePath.ToU8Span(), OpenMode.Read);
if (rc.IsFailure())
{
return(false);
}
using (file)
{
header = new AesXtsFileHeader(file);
return(header.TryDecryptHeader(keyPath, KekSource, ValidationKey));
}
}