EIP-712 Derive Macro

This crate provides a derive macro Eip712 that is used to encode a rust struct into a payload hash, according to https://eips.ethereum.org/EIPS/eip-712

The trait used to derive the macro is found in ethers_core::transaction::eip712::Eip712 Both the derive macro and the trait must be in context when using

This derive macro requires the #[eip712] attributes to be included for specifying the domain separator used in encoding the hash.

NOTE: In addition to deriving Eip712 trait, the EthAbiType trait must also be derived. This allows the struct to be parsed into ethers_core::abi::Token for encoding.

Optional Eip712 Parameters

The only optional parameter is salt, which accepts a string that is hashed using keccak256 and stored as bytes.

Example Usage

use ethers_contract::EthAbiType;
use ethers_derive_eip712::*;
use ethers_core::types::{transaction::eip712::Eip712, H160};

#[derive(Debug, Eip712, EthAbiType)]
#[eip712(
name = "Radicle",
version = "1",
chain_id = 1,
verifying_contract = "0x0000000000000000000000000000000000000000"
// salt is an optional parameter
salt = "my-unique-spice"
)]
pub struct Puzzle {
pub organization: H160,
pub contributor: H160,
pub commit: String,
pub project: String,
}

let puzzle = Puzzle {
organization: "0000000000000000000000000000000000000000"
.parse::<H160>()
.expect("failed to parse address"),
contributor: "0000000000000000000000000000000000000000"
.parse::<H160>()
.expect("failed to parse address"),
commit: "5693b7019eb3e4487a81273c6f5e1832d77acb53".to_string(),
project: "radicle-reward".to_string(),
};

let hash = puzzle.encode_eip712()?;

Limitations

At the moment, the derive macro does not recursively encode nested Eip712 structs.

There is an Inner helper attribute #[eip712] for fields that will eventually be used to determine if there is a nested eip712 struct. However, this work is not yet complete.