Hello I'd like to create a hash using ethersjs that encodes a number of arguments. I previously used ethereumjs-abi's soliditySHA3 function but not sure which of ethersjs crypto utilities is the correct one. It currently looks like this:

const hash = "0x" + abi.soliditySHA3("address", "uint256", "uint256", "address"],[recipient, amount, nonce, contractAddress]).toString("hex");

signature = await web3.eth.personal.sign(hash, from, pwd);

Also, I'd like to know how to make an Ethereum-aware signature using this hash and the sender's address (above). A contract should then be able to decrypt this signature using the same signature, nonce and expected amount. Like so:

 function claimPayment(uint256 amount, uint256 nonce, bytes memory signature) public {
        require(!usedNonces[nonce], "contract already used");
        usedNonces[nonce] = true;

        // this recreates the message that was signed on the client
        bytes32 message = prefixed(keccak256(abi.encodePacked(msg.sender, amount, nonce, this)));
        require(recoverSigner(message, signature) == owner, "signer must be same as owner");


source: Solidity docs


I have found that ethers carries a utility that mimics ethereumjs in the following: ethers.utils.solidityKeccak256.

I also believe the web3 sign can be recreated with the following:

const signingKey = new ethers.utils.SigningKey(connectedWallet.privateKey);
const messageDigest = "0x" + ethers.utils.solidityKeccak256(["address", "uint256", "uint256", "address"],[recepient, amount, nonce, contract.address])
const signature = signingKey.signDigest(messageDigest);

However, I get an error, "Error: invalid hexidecimal string" and still debuggint this.


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