Based on NIST KATs, build a list of Tests for the instantiated AES algorithm.
e.g. runTests $ makeAESTests (undefined :: AES128)
This is just a hack-job, if the BlockCipher instance doesn't toss keys of incorrect length then you'll get this test running, say, AES128 being tested with the first 128 bits of AES192 and AES256 tests.