code: def crypto_scalarmult_base(n):
      
      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)[:]
docs: Computes and returns the scalar product of a standard group element and an
      integer ``n``.
  
      :param n: bytes
      :rtype: bytes