public static extern void MD5Init(ref MD5Obj Obj, byte[] Data, uint Size);
 public static extern void MD5Encrypt(ref MD5Obj Obj, byte[] input, [In, Out] byte[] output, int len);
 public static extern void MD5Encrypt(ref MD5Obj Obj, byte[] input, [In, Out] byte[] output, int len);
 public static extern void MD5Init(ref MD5Obj Obj, byte[] Data, uint Size);