secretstream support?

[spieglt]

Are there plans to implement the secretstream API? If so, would it be in webassembly? I saw xchacha20poly1305 mentioned in this issue. Wondering if I'll be able to use this for a react-native version of a project of mine.

[spieglt]

If I take a pass at writing it, would anyone be willing to review?

[emilbayes]

Of course! Happy to review

[spieglt]

Okay, I figured I should start with hchacha20 since the issue I linked to said it was somewhat involved. The test at the bottom should be in https://github.com/sodium-friends/sodium-test, and I can submit a separate PR for that, but I wanted to run what I have so far by you so you can tell me if I'm on the wrong track. PR is #55. Thanks!

[spieglt]

The rest of secretstream is in #57.