Web3 Token

Web3 Token is a new way to authenticate users. See this article for more info (later I'll add this info to this readme). Implementation of EIP-4361.

Version 2 updates 🎉

• I'm now 90% following EIP-4361. Why 90%? Because i don't like some things in that standard that makes it more difficult to use it for developers.
• body (3rd parameter) is now deprecated.

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Install

With web3 package:

$ npm i web3-token web3

or with ethers package:

$ npm i web3-token ethers

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Example usage (Client side)

Using Web3 package:

import Web3 from 'web3';
import Web3Token from 'web3-token';

// Connection to MetaMask wallet
const web3 = new Web3(ethereum);
await ethereum.request({ method: 'eth_requestAccounts'});

// getting address from which we will sign message
const address = (await web3.eth.getAccounts())[0];

// generating a token with 1 day of expiration time
const token = await Web3Token.sign(msg => web3.eth.personal.sign(msg, address), '1d');

// attaching token to authorization header ... for example

Using Ethers package:

import { ethers } from "ethers";
import Web3Token from 'web3-token';

// Connection to MetaMask wallet
const provider = new ethers.providers.Web3Provider(window.ethereum);
const signer = provider.getSigner();

// generating a token with 1 day of expiration time
const token = await Web3Token.sign(async msg => await signer.signMessage(msg), '1d');

// attaching token to authorization header ... for example

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Example usage (Server side)

const Web3Token = require('web3-token');

// getting token from authorization header ... for example
const token = req.headers['Authorization']

const { address, body } = await Web3Token.verify(token);

// now you can find that user by his address 
// (better to do it case insensitive)
req.user = await User.findOne({ address });

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Handle exceptions

const generateToken = async () => {
  if (!window.ethereum) {
    return console.log('Please install and activate the metamask extension!');
  }

  const provider = new ethers.providers.Web3Provider(window.ethereum);
  const signer = provider.getSigner();

  try {
    return await Web3Token.sign(async msg => {
      try {
        return await signer.signMessage(msg);
      }
      catch (err) {
        const { reason } = err;
        if (reason === "unknown account #0") {
          return console.log('Have you unlocked metamask and are connected to this page?')
        }

        console.log(err.toString());
      }
    }, '1d');
  }
  catch (err) {
    if (/returns a signature/.test(err.toString())) {
      return;
    }
    console.log(err.toString());
  }
}

Advanced usage with options (Client&Server side)

// I assume here a lot of things to be imported 😀

const token = await Web3Token.sign(async msg => await signer.signMessage(msg), {
  domain: 'worldofdefish.com',
  statement: 'I accept the WoD Terms of Service: https://service.org/tos',
  expire_in: '3 days',
  // won't be able to use this token for one hour
  not_before: new Date(Date.now() + (3600 * 1000)),
  nonce: 11111111,
});

const { address, body } = await Web3Token.verify(token, {
  // verify that received token is signed only for our domain
  domain: 'worldofdefish.com'
});

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API

sign(signer, options)

Name	Description	Required	Example
signer	A function that returns a promise with signature string eg: web3.personal.sign(data, address)	required	(body) => web3.personal.sign(body, '0x23..1234')
options	An options object or, if passed a string, will be used as an expire_in option	optional (default: '1d')	{} or '1 day'
options.expires_in	A string that represents a time span (see ms module) or a number of milliseconds	optional (default: 1d)	'1 day'
options.not_before	A date after which the token becomes usable	optional	new Date('12-12-2012')
options.expiration_time	A date till when token is valid. Overwrites expire_in parameter	optional	new Date('12-12-2012')
options.statement	A human-readable ASCII assertion that the user will sign, and it must not contain '\n'	optional	'I accept the ServiceOrg Terms of Service: https://service.org/tos'
options.domain	Authority that is requesting the signing.	optional(Unless verifier won't ask for it)	'example.com'
options.nonce	A randomized token used to prevent replay attacks, at least 8 alphanumeric characters.	optional	12345678
options.request_id	A system-specific identifier that may be used to uniquely refer to the sign-in request.	optional	231

verify(token, options)

Name	Description	Required	Example
token	A token string that is generated from sign()	required	...
options	An options object	optional	{ domain: 'example.com' }
options.domain	The domain you want to accept	optional	'example.com'

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License

Web3 Token is released under the MIT license. © 2021 Miroslaw Shpak