def randombytes(size):
    """
    Returns ``size`` number of random bytes from a cryptographically secure
    random source.

    :param size: int
    :rtype: bytes
    """
    buf = ffi.new("unsigned char[]", size)
    lib.randombytes(buf, size)
    return ffi.buffer(buf, size)[:]
Returns ``size`` number of random bytes from a cryptographically secure
    random source.

    :param size: int
    :rtype: bytes