padding.py 文件源码

def _byte_unpadding_update(buffer_, data, block_size):
    if buffer_ is None:
        raise AlreadyFinalized("Context was already finalized.")

    if not isinstance(data, bytes):
        raise TypeError("data must be bytes.")

    buffer_ += data

    finished_blocks = max(len(buffer_) // (block_size // 8) - 1, 0)

    result = buffer_[:finished_blocks * (block_size // 8)]
    buffer_ = buffer_[finished_blocks * (block_size // 8):]

    return buffer_, result