EIP712

[BlinkyStitt]

I'm wanting to hash 0x orders and they use EIP712. I'm trying to write this in rust and not javascript. Is this currently possible with rust-web3?

[tomusdrw]

@WyseNynja We don't have that method exposed yet (PRs welcome!). You can freely extend rust-web3 though, you will just need to define all the input and output types and their deserialization.

[That3Percent]

There is a separate crate which may fit the bill here: eip-712

[gakonst]

Doesn't that conflict with this library's MIT license?

[tomusdrw]

@gakonst Correct, the crate mentioned here can't really be included in web3, but you are fine to build a GPL-3.0 project that uses both web3 and eip-712 to achieve what you need.

[That3Percent]

Dismayed by the licensing, I went ahead to build a replacement for the GPL licensed eip-712 crate that is MIT licensed and is based on structs instead of JSON. It's not yet batteries included, but you can see examples of how to use it in the tests section.

https://github.com/graphprotocol/eip-712-derive

Example usage:

struct Mail {
    from: Person,
    to: Person,
    contents: String,
}
// This is all that is necessary to implement any EIP-712 signable struct
impl StructType for Mail {
    const TYPE_NAME: &'static str = "Mail";
    fn visit_members<T: MemberVisitor>(&self, visitor: &mut T) {
        visitor.visit("from", &self.from);
        visitor.visit("to", &self.to);
        visitor.visit("contents", &self.contents);
    }
}

/* Elided Person struct, etc */

fn test() -> (Signature, RecoveryId) {
 let domain = DomainStruct {
        name: "Ether Mail".to_owned(),
        version: "1".to_owned(),
        chain_id: chain_id::MAIN_NET,
        verifying_contract: Address(
            (&(hex::decode("CcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC").unwrap())[..])
                .try_into()
                .unwrap(),
        ),
    };
let domain_separator = DomainSeparator::new(&domain);
let message = Mail {
        from: Person { /* elided */ },
        to: Person { /* elided */ },
        contents: "Hello, Bob!".to_owned(),
    };
 sign_typed(&domain_separator, &message, &pk)
}