func TestTe(t *testing.T) {
	for i := 0; i < 256; i++ {
		s := uint32(sbox0[i])
		s2 := mul(s, 2)
		s3 := mul(s, 3)
		w := s2<<24 | s<<16 | s<<8 | s3
		te := [][256]uint32{te0, te1, te2, te3}
		for j := 0; j < 4; j++ {
			if x := te[j][i]; x != w {
				t.Fatalf("te[%d][%d] = %#x, want %#x", j, i, x, w)
			}
			w = w<<24 | w>>8
		}
	}
}

// Test that decryption tables are correct.