As signatures can be daunting at times, this is a library aiming to implement universal signature verification, supporting:

• Standard message verification (eth_sign)
• EIP-712 Typed data verification (eth_signTypedData_v*)
• ERC-1271 Smart contract on-chain verification (isValidSignature)
• ERC-6492: Signature verification for pre-deploy counterfactual contracts

Simple eth_sign verification

import ethers from 'ethers';
import { verifyMessage } from '@ambire/signature-validator';

const provider = new ethers.providers.JsonRpcProvider('https://polygon-rpc.com')

async function run() {
	// Replace `ethers.verifyMessage(message, signature) === signer` with this:
	const isValidSig = await verifyMessage({
	    signer: '0xaC39b311DCEb2A4b2f5d8461c1cdaF756F4F7Ae9',
	    message: 'My funds are SAFU with Ambire Wallet',
	    signature: '0x9863d84f3119ac01d9e3bf9294e6c0c3572a07780fc7c49e8dc913806f4b1dbd4cc075462dc84422a9b981b2556f9c9197d76da7ba3603e53e9300869c574d821c',
	    // this is needed so that smart contract signatures can be verified
	    provider,
	})
	console.log('is the sig valid: ', isValidSig)
}
run().catch(e => console.error(e))

For more examples, you can check the /tests folder

To test signatures in an easier manner, you can use the signature-validator UI here: https://sigtool.ambire.com/

A formal audit was done on the ERC-6492 reference implementation used here, and all remarks were resolved. You can find the audit here. This repo uses a simplified variant of that reference implementation that the audit also applies to (except all of the issues related to prepare which is not used here).

Furthermore, you can self-audit the library quite easily as it's only ~80 lines of code (index.js).

npm i --development
npm test