Answers for "sign data metamask"

sign data metamask

signTypedDataV4Button.addEventListener('click', function (event) {
  event.preventDefault();

  const msgParams = JSON.stringify({
    domain: {
      // Defining the chain aka Rinkeby testnet or Ethereum Main Net
      chainId: 1,
      // Give a user friendly name to the specific contract you are signing for.
      name: 'Ether Mail',
      // If name isn't enough add verifying contract to make sure you are establishing contracts with the proper entity
      verifyingContract: '0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC',
      // Just let's you know the latest version. Definitely make sure the field name is correct.
      version: '1',
    },

    // Defining the message signing data content.
    message: {
      /*
       - Anything you want. Just a JSON Blob that encodes the data you want to send
       - No required fields
       - This is DApp Specific
       - Be as explicit as possible when building out the message schema.
      */
      contents: 'Hello, Bob!',
      attachedMoneyInEth: 4.2,
      from: {
        name: 'Cow',
        wallets: [
          '0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826',
          '0xDeaDbeefdEAdbeefdEadbEEFdeadbeEFdEaDbeeF',
        ],
      },
      to: [
        {
          name: 'Bob',
          wallets: [
            '0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB',
            '0xB0BdaBea57B0BDABeA57b0bdABEA57b0BDabEa57',
            '0xB0B0b0b0b0b0B000000000000000000000000000',
          ],
        },
      ],
    },
    // Refers to the keys of the *types* object below.
    primaryType: 'Mail',
    types: {
      // TODO: Clarify if EIP712Domain refers to the domain the contract is hosted on
      EIP712Domain: [
        { name: 'name', type: 'string' },
        { name: 'version', type: 'string' },
        { name: 'chainId', type: 'uint256' },
        { name: 'verifyingContract', type: 'address' },
      ],
      // Not an EIP712Domain definition
      Group: [
        { name: 'name', type: 'string' },
        { name: 'members', type: 'Person[]' },
      ],
      // Refer to PrimaryType
      Mail: [
        { name: 'from', type: 'Person' },
        { name: 'to', type: 'Person[]' },
        { name: 'contents', type: 'string' },
      ],
      // Not an EIP712Domain definition
      Person: [
        { name: 'name', type: 'string' },
        { name: 'wallets', type: 'address[]' },
      ],
    },
  });

  var from = web3.eth.accounts[0];

  var params = [from, msgParams];
  var method = 'eth_signTypedData_v4';

  web3.currentProvider.sendAsync(
    {
      method,
      params,
      from,
    },
    function (err, result) {
      if (err) return console.dir(err);
      if (result.error) {
        alert(result.error.message);
      }
      if (result.error) return console.error('ERROR', result);
      console.log('TYPED SIGNED:' + JSON.stringify(result.result));

      const recovered = sigUtil.recoverTypedSignature_v4({
        data: JSON.parse(msgParams),
        sig: result.result,
      });

      if (
        ethUtil.toChecksumAddress(recovered) === ethUtil.toChecksumAddress(from)
      ) {
        alert('Successfully recovered signer as ' + from);
      } else {
        alert(
          'Failed to verify signer when comparing ' + result + ' to ' + from
        );
      }
    }
  );
});