Using the API of NACL to Implement a Crypto Protocol?

The random padding helped a little bit, but not quite enough. I feel like they were influenced by the library API they had as opposed to trying to design what they wanted to have and then picking the libraries to fit that need. That's an interesting point because picking your primitives is very important when you're trying to implement a specific one. But it feels like a lot of the protocol decisions of three, ma, the end to end part and the C2s, the client server part, were hamstrung by the API of NACL.