Why the EIP712Domain defined by evmos inconsistent with the EIP712 protocol

[luchenqun]

I found that ethers.js cannot be used to provide EIP712 signatures for evmos due to the main reason that ethers.js and the EIP domain definitions defined by evmos have different types.

The EIP712 domain defined by ethers.js is as follows, for details please refer to https://github.com/ethers-io/ethers.js/blob/main/src.ts/hash/typed-data.ts#L83-L89 and https://eips.ethereum.org/EIPS/eip-712

const domainFieldTypes: Record<string, string> = {
    name: "string",
    version: "string",
    chainId: "uint256",
    verifyingContract: "address",
    salt: "bytes32"
};

The EIP712 domain defined by evmos is as follows, for details please refer to https://github.com/evmos/evmos/blob/main/ethereum/eip712/eip712_legacy.go#L89C19-L110C4

[
    {
        "Name":"name",
        "Type":"string"
    },
    {
        "Name":"version",
        "Type":"string"
    },
    {
        "Name":"chainId",
        "Type":"uint256"
    },
    {
        "Name":"verifyingContract",
        "Type":"string"
    },
    {
        "Name":"salt",
        "Type":"string"
    }
]

There is an inconsistency between the type defined in quarix and the verifyingContract and salt values provided by ethers.js.

The ethers.js library provides the signTypedData method for signing structured data following the EIP712 standard. However, it only allows users to provide the data domain and does not support custom EIP712 domain definitions. This causes a problem when validating signatures in evmos as the provided signature does not match the expected.