An express.js authentication middleware using AWS Cognito & the CognitoExpress package

cognitoMw.js

const CognitoExpress = require('cognito-express')

exports.validateToken = (req, res, next) => {
    if (req.headers && req.headers.authorization && req.headers.authorization.split(' ')[0] === 'Bearer') {
        let cognitoConfig = {
            region: process.env.COGNITO_REGION,
            cognitoUserPoolId: process.env.COGNITO_USERPOOL_ID,
            tokenUse: 'id',
            tokenExpiration: 3600000
        }

        if(req.headers['bm-cognito-token-type']) {
            cognitoConfig.tokenUse = req.headers['bm-cognito-token-type'].toLowerCase()
        }

        const cognitoExpress = new CognitoExpress(cognitoConfig)

        let token = req.headers.authorization.split(' ')[1]

        cognitoExpress.validate(token, function(err, response) {
            if (err) {
                req.user = undefined
                res.status(401).json({ error: 'Unauthorized.' })
            } else {
                req.user = response
                next()
            }
        })
    } else {
        req.user = undefined
        res.status(401).json({ error: 'Unauthorized.' })
    }
}