def unpad_aes256(s):
    """
    Removes padding from an input string based on a given block size.
    :param s: string
    :returns: The unpadded string.
    """
    if not s:
        return s

    try:
        return Padding.removePadding(s, blocksize=AES.block_size)
    except AssertionError:
        # if there's an error while removing padding, just return s.
        return s
Removes padding from an input string based on a given block size.
    :param s: string
    :returns: The unpadded string.