It's better if you don't build crypto directly into your application at all, because you can still screw things up even if you build on Nacl. But with that said: Sodium/Nacl is better than virtually any of your other options for working directly with cryptography.

> It's better if you don't build crypto directly into your application at all, because you can still screw things up even if you build on Nacl.

Nacl was built to provide an API that is incredibly hard to screw up. That was one of djbs primary motivations. If you just need asymmetric encryption, or signing, or hashing, then it's the bees knees. These broad concepts aren't difficult to comprehend, and every developer should strive to understand and be able to use them. We shouldn't be encouraging people to be afraid... especially when things like dumb, plaintext username and password authentication is routinely implemented by developers without a second thought already.

Nacl makes it hard to screw up the constructions. It doesn't make it hard to make invalid assumptions about what a signed encrypted blob actually means.

+ makes it easy to add two numbers. It doesn't make it hard to make invalid assumptions about what adding two numbers together actually means.

Nacl is a good thing. But crypto is just a tool. It's not a magic wand. People have already built vulnerable systems by making bogus assumptions about what Nacl can do.

That's a shame :(

Can you recommend how to wrap crypto _around_ our applications if we aren't building it in?

"It's better if you don't build crypto directly into your application at all"

Plaintext all of the things! :P

I'm curious to know what you'd recommend for people who are looking to build applications around novel network protocols that aren't interested in the the certificate authority aspect of TLS?

There's no reason you have to use CAs to authenticate TLS. Plenty of enterprise tools keep whitelists of certificate hashes instead.

There's an RFC on TLS with raw public keys that you should probably check out: http://tools.ietf.org/html/draft-ietf-tls-oob-pubkey-02.

There are several TLS modes that don't use certificates. SRP and PSK are the two that I have some limited experience with. Both require sharing a password or key beforehand through some other medium.

If you're not concerned with man-in-the-middle attacks, then you could also use the ANON modes.

If you control the client software, theres no reason to use a certificate authority instead of making your own CA or just using self-signed certificates.

This maybe:

https://github.com/okTurtles/dnschain

To add to what others have said here, I'll point you to the authors of TweetNaCl, which sort-of competes with Sodium:

http://tweetnacl.cr.yp.to/papers.html

Little is said, other than that TweetNaCl is smaller and thus more easily auditable. No criticism. No pointing out failures. Considering the source, that's IMO a serious compliment. (For comparison, read what is said of OpenSSL...)

So in short, Sodium is a great library. It was forked from NaCl (the most trustable there is) and has some good features added, like scrypt, BLAKE2 and ChaCha.

I think NaCl, TweetNaCl, and Sodium are a great ecosystem, each with different strengths. All great libraries, and the only ones I'd recommend unless you're doing TLS.

The ecosystem is actually bigger, and includes projects such as TweetNaCl.js (pure Javascript implementation), Salt (pure PHP implementation) and Chaos.NaCl (pure C# implementation).

All these projects play well with each other: they have a decent set of primitives and constructions in common, accessible via a very similar API.

I believe it's safe to use in the sense of being stable. I don't believe they've had a full security audit yet, though.

People have weird ideas about the protective powers of a "full security audit". This is Bernstein, Lange, and Schwabe's code. There aren't many auditors qualified to review it.

It's more about having a third party look at it rather than the credentials of the authors being in question.

I understand the idea, but again: there aren't many third parties that are qualified to evaluate crypto code at all.

Theorem provers?

If you want proven crypto, there's always this project: https://github.com/idris-hackers/idris-crypto

Let's not wait 5 years then crowdfund it like TrueCrypt ;)

It's probably save to use in the sense that there are a number of projects (dnscrypt, zeromq, tox, ...) are using it already.

When I first started paging through the docs it seemed like sort of a useless, dangerous thing. But now (after reading your comment and looking those projects up) it seems like it's an officially blessed version of NaCL, which makes it seem much safer.