Using a pre-computed Domain Hash with signTypedData? (answer: you cannot)

[thegostep]

Using the hashed domain directly would make integration with this standard easier.
https://eips.ethereum.org/EIPS/eip-2612#specification

[ricmoo]

No, it’s actually not possible to do this.

The contents of the hash are required by any higher-level UI. For example, MetaMask needs to know the validating address and chain ID since it checks both those things before showing the message to the user. If you pass in the hash instead, there would be no way for MetaMask to vet these.

I’m not familiar with that EIP, but will look into it shortly to see if I have any guidance. :)

My guess is you might have to use the TypedDataEncoder directly though.

[ricmoo]

It looks like you just need to use EIP-712 normally. The EIP provides the structure to use, for ethers simply remove the EIP712Domain structure, and include the domain values.

It should just work, I think. If I understand the EIP properly.

[thegostep]

I see - the challenge is wanting to have a generalized solution that does not rely on hardcoding the domain for each token being interacted with.

It seems like this is a shortcoming of the standard.

[ricmoo]

Yeah... The EIP is in draft though, so you should feel free to comment on it. :)

There are plenty of comments, but the latest is from April...

[ricmoo]

(converting this to a discussion)

[frangio]

This is a shortcoming of EIP712 IMO... I raised this in Ethereum Magicians but no one replied. 😕

https://ethereum-magicians.org/t/eip-712-eth-signtypeddata-as-a-standard-for-machine-verifiable-and-human-readable-typed-data-signing/397/29?u=frangio

[ricmoo]

I have made no effort to hide the fast I’m against EIP-712 in general, but I agree. :)

I’m working on an article now to explain my EIPs to do away with EIP-712 and solve the real UX problem. :)