def crypto_scalarmult_base(n):
    """
    Computes and returns the scalar product of a standard group element and an
    integer ``n``.

    :param n: bytes
    :rtype: bytes
    """
    q = ffi.new("unsigned char[]", crypto_scalarmult_BYTES)

    rc = lib.crypto_scalarmult_base(q, n)
    ensure(rc == 0,
           'Unexpected library error',
           raising=exc.RuntimeError)

    return ffi.buffer(q, crypto_scalarmult_SCALARBYTES)[:]