[Naive Receiver] How do I sign data in Foundry?

[AlexGorgut]

I think I found how to exploit this contract, but I don't understand how to generate a NaiveReceiverTest::signature to pass in BasicForwarder::execute function.

I found the similar vulnerability that been exploited using hardhat and ether.js library(
Image (https://github.com/user-attachments/assets/60c05a63-ed9c-4d64-9b20-729b5ca25b54) )
Exact line to generate signature :

const signature = await wallet.signTypedData(domain, types, data);

But I don't understand how to get this signature function in Foundry, as there is no existing library that I can import to generate it. These are the last lines of my test that I am stuck on in Foundry:

    bytes32 memory domain = forwarder.domainSperator();
    bytes32 memory types = forwarder.getRequestTypehash();
    bytes32 memory dataHash = forwarder.getDataHash(request);

    bytes memory signature = ??? ;


    forwarder.execute(request,signature);

[Schereo]

You can get the signature from the forge cheat code vm.sign() as explained here: https://book.getfoundry.sh/cheatcodes/sign.

So basically you would do the following to obtain the signature:

(uint8 v, bytes32 r, bytes32 s) = vm.sign(playerPk, eip712Hash);
bytes memory signature = abi.encodePacked(r, s, v);

In addition make sure to supply the hash in a EIP721 compliant format. That means to use your dataHash and hash it again with the following parameters:

bytes32 eip712Hash = keccak256(
            abi.encodePacked("\x19\x01", forwarder.domainSeparator(), dataHash)
        );

For more information have a look at the EIP712: https://eips.ethereum.org/EIPS/eip-712