You don't have to follow TDD at all in order to build a test suite for a project. I think all anyone's suggesting is that some of the complicated nature of get

You don't have to follow TDD at all in order to build a test suite for a project. I think all anyone's suggesting is that some of the complicated nature of getting crypto right actually can be put into a suite of tests. I know I could come up with a very basic set of test cases, and my only experience with TLS is reading parts of some book I found in my company's library. Heck, OpenSSL has a ton of tests it runs on every build, I know this much. And even in Haskell you'd need tests. At no time will you ever be able to write code without testing it.