def test_AddRoundKey(self):
# for input = key the result should be 0
instance = AES(key=("test" * 3))
input = [gf._cache.fetch_int(i) for i in xrange(16)]
key = [gf._cache.fetch_int(i) for i in xrange(16)]
expected_result = [gf(0)] * 16
result = instance.AddRoundKey(input, key)
self.assertEquals(expected_result, result)
# for each position the result should be the xor result
input = [gf._cache.fetch_int(i) for i in xrange(16)]
key = [gf._cache.fetch_int(i + i) for i in xrange(16)]
result = instance.AddRoundKey(input, key)
self.assertEquals(len(result), len(input))
for i in xrange(len(result)):
self.assertEquals(input[i] + key[i], result[i])
# inversion test: applying the same key again should invert the effect
input = [gf._cache.fetch_int(2 * i) for i in xrange(16)]
key = [gf._cache.fetch_int(i**2) for i in xrange(16)]
result = instance.AddRoundKey(input, key)
self.assertEquals(input, instance.AddRoundKey(result, key))
