o 5 h @sdddZdS)FcCsH|ddkr td|}||krtd||f|d||||dS)aCreate a stateful counter block function suitable for CTR encryption modes. Each call to the function returns the next counter block. Each counter block is made up by three parts: +------+--------------+-------+ |prefix| counter value|postfix| +------+--------------+-------+ The counter value is incremented by 1 at each call. Args: nbits (integer): Length of the desired counter value, in bits. It must be a multiple of 8. prefix (byte string): The constant prefix of the counter block. By default, no prefix is used. suffix (byte string): The constant postfix of the counter block. By default, no suffix is used. initial_value (integer): The initial value of the counter. Default value is 1. Its length in bits must not exceed the argument ``nbits``. little_endian (boolean): If ``True``, the counter number will be encoded in little endian format. If ``False`` (default), in big endian format. allow_wraparound (boolean): This parameter is ignored. An ``OverflowError`` exception is always raised when the counter wraps around to zero. Returns: An object that can be passed with the :data:`counter` parameter to a CTR mode cipher. It must hold that *len(prefix) + nbits//8 + len(suffix)* matches the block size of the underlying block cipher. z'nbits' must be a multiple of 8zGInitial value takes %d bits but it is longer than the counter (%d bits)) counter_lenprefixsuffix initial_value little_endian) ValueError bit_length)nbitsrrrr allow_wraparoundiv_blrg/var/www/html/construction_image-detection-poc/venv/lib/python3.10/site-packages/Crypto/Util/Counter.pynews 'rN)rrrFF)rrrrrs