Splitting tests

Another issue where opinions might be very helpful is the question whether some tests should be split into more files. Currently, algorithms for symmetric encryption have just one test file, that mixes tests for encryption and decryption. In other cases (e.g. RSA encryption) test vectors that require indistinguishable behavior during decryption are mixed with test vectors for other purposes. Maybe it would be preferable to split the test files for different purposes (e.g. one for encryption and and one for decryption). It might even make sense to add separate tests for invalid/insecure or otherwise strange parameter selections.