A little help migrating from Ethers

[rgarcia1129]

Hi all,
I'm working on the server side looking to rewrite the following function using viem instead of ethers. It seems simple enough and I've kinda made some progress but the hashes continue to not match and the sign message gives me an error of "personal_sign" is not supported.

Any help would be appreciated thanks!

const provider = new ethers.providers.AlchemyProvider(
"homestead",
"<ALCHEMY_API_KEY"
);

const signer = new Wallet(
"<SIGNER_ADDRESS>",
provider
);

const hash = ethers.utils.solidityKeccak256(
["bytes"],
[
ethers.utils.defaultAbiCoder.encode(
["address", "uint256"],
[minter, salt]
),
]
);
const signature = await signer.signMessage(ethers.utils.arrayify(hash));

return signature

[rgarcia1129]

I know that signer would be defined like this so Im really just looking for matching the hashes and generating the signature.

const signer = createWalletClient({ account: privateKeyToAccount( "0x" + <PRIVATE_KEY>" ), chain: mainnet, transport: http( "https://eth-mainnet.g.alchemy.com/v2/<ALCHEMY_KEY" ) });

[jxom]

You may be getting signature differences because viem does not support signing of raw hex/bytes data yet. There is actually a PR open for that right now, and it should be released by the end of the week.

Here is an viem equivalent example of the code you gave:

import { createWalletClient, http, keccak256, encodeAbiParameters, encodePacked } from 'viem'
import { privateKeyToAccount } from 'viem/accounts' 

const walletClient = createWalletClient({
  account: privateKeyToAccount('0x...')
  chain: mainnet,
  transport: http('https://eth-mainnet.alchemyapi.io/v2/ALCHEMY_API_KEY')
})

const hash = keccak256(
  encodePacked(
    ['bytes'], 
    [encodeAbiParameters(['address', 'uint256'], [minter, salt])]
  )
 )

await walletClient.signMessage({ message: { raw: hash } })

Note: the raw attribute in signMessage won't work yet! Waiting until #610 is merged.

[rgarcia1129]

thanks for the quick response!
when using this code snippet to get the hash I get the following error: Argument of type '(bigint | 0x${string})[]' is not assignable to parameter of type 'never'.ts(2345)

[wslyvh]

I realize this an old discussion item, but ended up here while searching to migrate from defaultAbiCoder.encode
So sharing here for others..

The format for encodeAbiParameters is incorrect and you need to specify the types like

const encodedData = encodeAbiParameters(
    [{ type: 'address' }, { type: 'uint256' }],
    [minter, salt]
)

[rgarcia1129]

I figured out that these are generating equivalent hashes. Do you see any issues with this viem method of generating a hash?

  const encodedParams = ethers.utils.defaultAbiCoder.encode(
    ["address", "uint256"],
    [minter, salt]
  );

  const hash = ethers.utils.solidityKeccak256(["bytes"], [encodedParams]);

  const encodedParams = pad(
    encodePacked(["address", "uint256"], [minter, salt]),
    {
      dir: "left",
      size: 64,
    }
  );

  const hash = keccak256(encodedParams);

[jxom]

Should be fine!

[rgarcia1129]

will keep an eye that pr for the message signature 👍

[jxom]

Released!

[rgarcia1129]

already updated, it worked like a charm 👍 thanks for getting this out so quick

[sbauch]

I had some trouble getting this figured out, so in case anyone hits a similar issue and comes across this, this is the key aspect that helped me migrate from ethers:

You may be getting signature differences because viem does not support signing of raw hex/bytes data yet. There is actually a #610, and it should be released by the end of the week.

signMessage by default adds the EIP-191 format to the front of the signature. So you probably want to use this:

  const signature = await account.signMessage({ message: { raw: message } });