Verify Signature on Server-Side

---

Here we learn how to verify our signature on the server side.

index.js

const { SIWWeb3 } = require("@web3auth/sign-in-with-web3");

async function verifyMessage(jsonPayload) {
  const { header, payload, signature, network } = JSON.parse(jsonPayload);
  const message = new SIWWeb3({
    header,
    payload,
    network,
  });
  return await message.verify(payload, signature, network);
}

const verify = async function () {
  const isVerified = await verifyMessage(`{
    "header":{
       "t":"eip191"
    },
    "payload":{
       "domain":"localhost:1234",
       "address":"0xC3ac3a49b6f4D4221e886434496CF6F9327454d4",
       "statement":"Sign in with Ethereum to the app.",
       "uri":"http://localhost:1234",
       "version":"1",
       "chainId":1,
       "nonce":"JJ2V8kwvZZYueDLOB",
       "issuedAt": "2022-06-01T02:09:27.405Z"
    },
     "signature":{
        "s":"0xc0da894b04198482a58a5d043aa9704cdcc414371494093228a9241b0e62514c4860eb08352c37d32c13dd44a2e9d64a0652180e51fcd21b636360f5b16c64001c",
        "t":"eip191"
     },
     "network": "ethereum"
    }`);
  if (isVerified.success) {
    console.log("Verified!");
  } else {
    console.log("Not Verified!");
  }
};

verify();

The header, payload and signature fields will be obtained from the client side. We generate a SIWWeb3 message using the header and payload and then call the verify method with payload and signature as arguments.

If you haven't followed the previous tutorial or don't know how to execute this code, follow the steps :-

npm init --yes
npm install --save @web3auth/sign-in-with-web3 @babel/runtime

create index.js with the code given above and then execute

node index.js