/// <summary>
/// Creates a new <see cref="AesXtsFile"/> using the provided key.
/// </summary>
/// <param name="path">The full path of the file to create.</param>
/// <param name="size">The initial size of the created file.</param>
/// <param name="options">Flags to control how the file is created.
/// Should usually be <see cref="CreateFileOptions.None"/></param>
/// <param name="key">The 256-bit key containing a 128-bit data key followed by a 128-bit tweak key.</param>
public Result CreateFile(U8Span path, long size, CreateFileOptions options, byte[] key)
{
long containerSize = AesXtsFile.HeaderLength + Utilities.AlignUp(size, 0x10);
Result rc = BaseFileSystem.CreateFile(path, containerSize, options);
if (rc.IsFailure())
{
return(rc);
}
var header = new AesXtsFileHeader(key, size, path.ToString(), KekSource, ValidationKey);
rc = BaseFileSystem.OpenFile(out IFile baseFile, path, OpenMode.Write);
if (rc.IsFailure())
{
return(rc);
}
using (baseFile)
{
rc = baseFile.Write(0, header.ToBytes(false));
if (rc.IsFailure())
{
return(rc);
}
}
return(Result.Success);
}
private void WriteXtsHeader(AesXtsFileHeader header, string filePath, string keyPath)
{
Debug.Assert(PathTools.IsNormalized(filePath.AsSpan()));
Debug.Assert(PathTools.IsNormalized(keyPath.AsSpan()));
header.EncryptHeader(keyPath, KekSource, ValidationKey);
BaseFileSystem.OpenFile(out IFile file, filePath.ToU8Span(), OpenMode.ReadWrite);
using (file)
{
file.Write(0, header.ToBytes(false), WriteOption.Flush).ThrowIfFailure();
}
}
