[Mysterise]

You're testing recall only when asking about TLS. You may be testing recall for "how to implement a known algorithm", but there's still plenty of room for testing actual problem solving too.

If you are the interviewer, even if you are asking a standard "how to invert a binary tree" type algorithm question, you hold the cards to keep pushing the bounds for problem solving by extending the question.

[bawolff]

Well if you're willing to push boundries, you can certainly do the same with TLS. Ask why the TLS spec does X instead of Y, for various subtle design decisions. This is probably actually much easier to do than with a binary tree, as TLS is a lot more complex and a lot more subtle. It would certainly be an appropriate line of questioning if you were hiring a crypto engineer, not sure it would be relavent to a security engineer or software engineer.