wallet: support metamask signing

[tac0turtle]

Summary

Support metamask signing. This is a larger endeavour that is a mix of frontend work and sdk work. the team over at secret did an implementation that looks good to me.

• SIGN_MODE_EIP_191 scrtlabs/cosmos-sdk#183
• EIP191: Prettify Amino JSON scrtlabs/cosmos-sdk#194

Adding metamask support would enable new users to use their metamask account in cosmos.

Proposal

Look into the above pull requests/implementation in order to see if we can upstream it and enable it for more users in the ecosystem.

[cmgoes]

I am quite interested in how it's possible to work with metamask on Cosmos network?
Do you mean any evm side chain that has been scaffoled by Cosmos?

[facundomedica]

@ytdbuolf you can derive a Cosmos address from an Ethereum public key and sign messages using your private key. Secret is doing this with EIP191 and Amino StdDoc.
I'm currently working on finding an alternative to Amino, maybe an specific struct

[itsdevbear]

Injected wallets i.e Metamask would go a long way towards user adoption.

[tac0turtle]

there is work ongoing for metamask snaps, but i was talking to @sunnya97 about creating an rpc tool that would translate cosmos to eth semantics in order to use metamask without snaps

[tac0turtle]

this is being done by an external party no need to keep the issue open here

[itsdevbear]

@tac0turtle @sunnya97 and I were talking about this in Paris. I still owe him a doc....

Basically it's how Polaris works.