development diary -- UCAN

nichoth/fission-did is a repo I made to test the fission DID and UCAN libraries. See that readme & example.js file for discussion & examples.

fission-suite/ucan is the newer fission library for creating & working with UCANs. The difficult part is that the UCAN library and the webnative library each return a different interface for UCANs.

The ucans library has and API like this:

// in-memory keypair
const keypair = await ucan.keypair.create(ucan.KeyType.Edwards)

const u = await{
  audience: audience.did(), //recipient
  issuer: keypair, //signing key
  // ...

You'll notice that the keypair returned by ucans has a method .did.

Which is great for testing, because it makes it easy to create a temporary, in memory keypair. But how do you keep the same keypair over time?

Normally you would use the webnative library, which uses the keystore-idb library to get a key. It stores the keys in the browser via local forage, and you would get the did like this:

webnative.did.ucan().then(ourDID =>  // ...

But keystore-idb has a different keypair API than ucans. That's why I made nichoth/keystore-idb. It has a method getKeypair that returns the same keypair API as ucans.

I would submit this as a PR, but I don't really know what direction the rest of the team wants to go in regarding reconciling the webnative and ucans APIs. Also my test is a little wonky because I'm using a totally different bundler and test library.