token.js

const jwt = require('jsonwebtoken');

const SECRET_KEY = process.env.JWT_SECRET;

const PERMISSION = {
  principalId: 'user',
  policyDocument: {
    Version: '2012-10-17',
    Statement: [
      {
        Action: 'execute-api:Invoke',
        Effect: 'Allow',
        Resource: [
          // fill here the resources
        ],
      },
    ],
  },
};

function extractTokenFromHeader(e) {
  if (e.authorizationToken && e.authorizationToken.split(' ')[0] === 'Bearer') {
    return e.authorizationToken.split(' ')[1];
  } else {
    return e.authorizationToken;
  }
}

exports.createToken = ({ id, name, organization }) => {
  const EXPIRES_IN = 60 * 60 * 1000;

  return jwt.sign(
    {
      exp: Math.floor((Date.now() + EXPIRES_IN) / 1000),
      customer: {
        id,
        name,
        organization,
      },
    },
    SECRET_KEY
  );
};

exports.tokenValidation = async (event, ctx, callback) => {
  try {
    const token = extractTokenFromHeader(event);
    const decoded = jwt.verify(token, SECRET_KEY);
    ctx.customer = decoded.customer;

    return callback(null, {
      ...PERMISSION,
      principalId: decoded.customer.id,
    });
  } catch (e) {
    return callback('Unauthorized');
  }
};