feat(cli): Add web3signer KeySource

[merklefruit]

Relevant links:

• https://consensys.github.io/web3signer/web3signer-eth2.html#tag/Signing/operation/ETH2_SIGN
• https://docs.web3signer.consensys.io/how-to

This is analogue to #309 but for Web3Signer.

[EdwardJES]

Hey @merklefruit, are you guys open to community contributions at the moment?

[merklefruit]

Hey @EdwardJES for sure!

We also have a few "good-first-issue" issues sprinkled here and there, but we can provide guidance if you are interested in something more specific

[EdwardJES]

Okay awesome @merklefruit. This issue really interests me actually. I'll take a deeper look throughout the week on this API and post any details/questions I may have. Ty 🙏

[merklefruit]

Awesome, here for any questions :)

[EdwardJES]

Hey @merklefruit, I think I'll focus on getting the signing and listing (these map to the post and get requests in https://consensys.github.io/web3signer/web3signer-eth2.html#tag/Public-Key/operation/ETH2_LIST) commands in a draft PR as a first milestone. I think what would really help me is if you could provide an example of the usage of both of these commands, please 🙏 .

I've also been reading this as a reference: https://lighthouse-book.sigmaprime.io/validator-web3signer.html.

[merklefruit]

@EdwardJES sure!

so the goal is to add web3signer as KeySource so that we can use it in our pubkeys and delegate commands.
The delegate command is the most important, and it is used to read a keystore and generate signed delegation messages.
Here is an example:

bolt delegate --delegatee-pubkey 87a0...d3b3 local-keystore --path validators/ --password-path secrets/

in this example the KeySource is LocalKeystore which looks for an EIP-2335 keystore.
We also have one KeySource for Dirk and this issue is to add Web3Signer to that list.

For how I imagine this to be used:

bolt delegate --delegatee-pubkey 87a0...d3b3 web3signer [options]

[options] here will depend on what Web3Signer actually needs to connect, I haven't looked into its authorization methods yet.
Let me know if this is helpful in any way or if I can help clear up other parts.

post and get requests in consensys.github.io/web3signer/web3signer-eth2.html#tag/Public-Key/operation/ETH2_LIST) commands in a draft PR as a first milestone.

that sounds awesome.

[EdwardJES]

Hey @merklefruit, thank you for the prompt and detailed reply. That makes sense.

I just wanted to clarify another thing 🙏. The Web3Signer ETH2 REST API, specifically https://consensys.github.io/web3signer/web3signer-eth2.html#tag/Signing/operation/ETH2_SIGN does not support signing over arbitrary payloads, such as a delegation and only supports those listed in the type field of the schema. This makes having the Web3Signer server as a keysource a bit tough.

I believe the pubkeys command is still possible via https://consensys.github.io/web3signer/web3signer-eth2.html#tag/Public-Key/operation/ETH2_LIST.

There may be a path forward for the delegate command using the Web3Signer CLI, but unsure if this was the intention for this issue, https://docs.web3signer.consensys.io/how-to/load-keys.

Thank you.

[merklefruit]

Ah, good point, this throws a wrench in our plan to generate delegations.

However, I see that Web3Signer has implemented the commit-boost signing api here: Consensys/web3signer#1045 (just 2 days ago!)

I think we could use it for our goal since it allows for a generic consensus signature to be generated over an objectRoot, which is what we need. However since this feature is not released on Web3Signer yet, we'll have to either test by building it from source or wait for a release.

Even if there are no docs, it looks like they are following the commit-boost api specs that can be found here: https://commit-boost.github.io/commit-boost-client/api.

[EdwardJES]

Nice find! Awesome, I don't think the pending release should be a blocker. I'll work from this 💪

[EdwardJES]

Update: things are progressing well. I have the account listing and and signing tests passing for commit boost using the Web3Signer. I think I'll be able to have a draft PR up by end of the working week.

[merklefruit]

Great! Thanks for the update