ethers.utils._TypedDataEncoder.getPayload return verifyingContract in lowercase and it losts checksum

[fosgate29]

I was trying to sign a message following EIP 712 and I bumped this line in the ethers.js documentation:
https://github.com/ethers-io/ethers.js/blame/master/docs/v5/api/utils/hashing/README.md#L287

It is in lowercase:
verifyingContract: '0xcccccccccccccccccccccccccccccccccccccccc',

It had to be like this:
verifyingContract: '0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC',

I checked tests and if I am not wrong, we don't have a test for ethers.utils._TypedDataEncoder.getPayload

I added a simple test here and it failed:

ethers.js/packages/tests/src.ts/test-utils.ts

Line 769 in bcda16d

it(`encoding ${ test.name }`, function() {

 const payload = ethers.utils._TypedDataEncoder.getPayload(test.domain, test.types,test.data );
 assert.equal(payload.domain.verifyingContract, test.domain.verifyingContract, "verifyingContract");

For some reason it is setting verifyingContract to lower case in this line:

ethers.js/packages/hash/src.ts/typed-data.ts

Line 66 in bcda16d

return getAddress(value).toLowerCase();

and all address types to lowercase here

ethers.js/packages/hash/src.ts/typed-data.ts

Line 498 in bcda16d

return value.toLowerCase();

Is there any reason to return in lowercase?

[ricmoo]

The reason all addresses are set to lower case is some backends used to fail if they were checksummed in the JSON-RPC api.

I don't know which, if any, still do, but it is safer to do in case you are talking to services that use older Geth/Parity/Ganache/etc. backends that failed...

I seem to recall some backends would throw an error and others would simply "hang", never resolving or rejecting. So, now I lowercase all addresses that are sent over JSON-RPC... :)

Why do you want them not-lower-cased?

[fosgate29]

Thank you. Now I got it why it is in lowercase.

But everything started when in my frontend ( it was hardhat frontend example - https://github.com/nomiclabs/hardhat-hackathon-boilerplate) I tried to signed a message and it wasn't working.

I used same data in the EIP 712 and etherjs documentation to try to get the same result (signature) and I couldn't.
I debugged and it was executing that line (to lowercase) when signing a message. And because of that the signature was different.

But now I noticed the difference. I got different results because I used JsonRpcSigner instead of Wallet.

      const signer = this._provider.getSigner(0);
      let signature = await signer._signTypedData(domain, types, value);

I just don't know how to sign it using Wallet right now, but I will read docs again to learn and check if it is possible.

thanks.

[ricmoo]

Should be the same: wallet._signTypedData(...). :)

[fosgate29]

Actually I didn't t want to deal with a private key in my frontend. But since it isn't a bug, I need to figure it out how other projects solve this issue. Thanks

[ricmoo]

Oh. Sorry, I don’t think I understand the issue. What is the the problem you are having?

[fosgate29]

I noticed something weird here.

In the v5 documentation, we have an example of how to use Signer and EIP712.
I tried it using same data (domain, types and value) and I am not getting the same result in the Singer documentation.

https://github.com/ethers-io/ethers.js/blob/master/docs/v5/api/signer/README.md#L153

const signature = await signer._signTypedData(domain, types, value);
// '0x463b9c9971d1a144507d2e905f4e98becd159139421a4bb8d3c9c2ed04eb401057dd0698d504fd6ca48829a3c8a7a98c1c961eae617096cb54264bbdd082e13d1c'

I got this signature: 0x86c004b12bbb925d3303990a44ea81f4a11556bccb793f299a9c1e0b41b71bdc7e62811e2b5cbac5af302c8826eca2f69b7c4e961636339119cec5ec2695147a1b

And to make things worse, Signer example data is the same in the Wallet.sign test case (ethers.js/packages/tests/src.ts/test-utils.ts) and the signature is different. Wallet.sign test case gets this signature, which is the signature in EIP712 (https://github.com/ethereum/EIPs/blob/master/EIPS/eip-712.md) example that also gets:
0x4355c47d63924e8a72e509b65029052eb6c299d53a04e167c5775fd466751c9d07299936d304c153f6443dfa05f40ff007d72911b6f72307f996231605b915621c

And testcase also has the signature from EIP712:

ethers.js/packages/testcases/generation/src.ts/eip712-test.ts

Line 135 in bcda16d

signature: "0x4355c47d63924e8a72e509b65029052eb6c299d53a04e167c5775fd466751c9d07299936d304c153f6443dfa05f40ff007d72911b6f72307f996231605b915621c"