PayZen with NodeJS

config.json

{
	"payZen": {
		"url": "https://secure.payzen.eu/vads-payment/",
		"certificat": "XXXXXXXXX",
		"vads_site_id": "YYYYYYYY",
		"vads_version": "V2",
		"vads_ctx_mode": "TEST"
	}
}

controller.js

var _ = require('lodash');
var moment = require('moment');
var validator = require('validator');
var async = require('async');
var PayZenTransactionId = require('./payZenTransactionId');
var S = require('string');
var payZen = require('./payZen');
var config = require('config');


// create PayZen request:

exports.payZenRequest = function (req, res, next) {

    var user = req.user;
    var cart = req.cart;

    async.waterfall([

        function getNewTransactionId(cb) {
            PayZenTransactionId.getNewTransactionId(cb);
        },

        function createRequestParams(payZenTransactionId, cb) {

            var params = {};

            params.vads_version = config.payZen.vads_version;
            params.vads_trans_date = moment.utc().format('YYYYMMDDHHmmss');
            params.vads_ctx_mode = config.payZen.vads_ctx_mode;
            params.vads_site_id = config.payZen.vads_site_id;
            params.vads_page_action = cart.subscription ? 'REGISTER_PAY_SUBSCRIBE' /* = S5 */ : 'PAYMENT';
            params.vads_action_mode = 'INTERACTIVE';

            // TRANSACTION
            params.vads_trans_id = S(payZenTransactionId.transactionId).padLeft(6, '0').s;
            params.vads_amount = cart.subscription ? Math.round((cart.total - cart.subscription.price) * 100) : Math.round(cart.total * 100);
            params.vads_currency = 978; // euro
            params.vads_payment_config = 'SINGLE';

            // SUBSCRIPTION
            if (cart.subscription) {
                var tomorrow = moment().add(1, 'days');
                params.vads_sub_effect_date = tomorrow.format('YYYYMMDD');// subscription begins @ D+1
                params.vads_sub_amount = Math.round(cart.subscription.price * 100);
                params.vads_sub_currency = 978;
                params.vads_sub_desc = 'RRULE:FREQ=MONTHLY;COUNT=' + cart.subscription.term + ';BYMONTHDAY=5';
            }

            // SHOP RETURN
            params.vads_return_mode = 'GET';
            params.vads_url_return = config.baseUrl + '/cart';
            params.vads_url_error = config.baseUrl + '/cart?error=internal';
            params.vads_url_referral = config.baseUrl + '/cart?error=referral';
            params.vads_url_refused = config.baseUrl + '/cart?error=refused';
            params.vads_url_success = config.baseUrl + '/cart?success=1';
            params.vads_url_cancel = config.baseUrl + '/cart?cancel=1';

            // ORDER
            params.vads_order_id = cart.id;
            //vads_order_info1
            //vads_order_info2
            //vads_order_info3

            // CUSTOMER
            params.vads_cust_email = user.email;
            params.vads_cust_id = user.id;
            params.vads_cust_last_name = user.lastName;
            params.vads_cust_first_name = user.firstName;
            params.vads_cust_title = user.gender === 'fr' ? 'Mr' : 'Mme';

            // PAYMENT PAGE
            params.vads_payment_cards = 'CB';
            params.vads_available_languages = 'fr;en';
            params.vads_language = req.locale;

            // etc.

            var signature = payZen.signRequest(params);

            cb(null, _.assign(params, {signature: signature}));
        },

        function saveRequestParams(params, cb) {
            cart.payZen.request.params = params;
            cart.save(cb);
        }

    ], function (err, cart) {
        if (err) {
            return res.status(400).send({message: 'Unknown error...'});
        }
        res.status(200).json(cart.payZen.request);
    });
};


// Handle PayZen callback:

exports.payZenCallback = function (req, res, next) {

    var signature = req.body.signature;

    if (!payZen.verify(signature, req.body)) {
        return res.status(404).send({message: 'Signature unverified'});
    }

    // do your stuff!...

};

payZen.js

var _ = require('lodash');
var crypto = require('crypto');
var config = require('config');
var S = require('string');

var prefix = 'vads_';
var separator = '+';

function signRequest(params, certificat) {

    certificat = certificat || config.payZen.certificat;

    var string = _(params)
        .map(function (v, k) {
            return [k, v];
        })
        .filter(function (it) {
            return S(it[0]).startsWith(prefix);
        })
        .sortBy(function (it) {
            return it[0];
        })
        .map(function (it) {
            return it[1];
        })
        .value()
        .concat(certificat)
        .join(separator);

    var shasum = crypto.createHash('sha1');
    shasum.update(string);
    return shasum.digest('hex');
}

function verify(signature, params, certificat) {
    certificat = certificat || config.payZen.certificat;
    var expectedSignature = signRequest(params, certificat);
    return signature === expectedSignature;
}

exports.signRequest = signRequest;

exports.verify = verify;

payZenTransactionId.js

var mongoose = require('mongoose');
var moment = require('moment');

var payZenTransactionIdSchema = new mongoose.Schema({
    transactionId: {type: Number, default: 1},
    transactionDate: {type: String} // yyyymmdd
});

payZenTransactionIdSchema.statics.getNewTransactionId = function (callback) {
    var now = moment().format('YYYYMMDD');
    this.findOneAndUpdate({transactionDate: now}, {$inc: {transactionId: 1}}, {'new': true, upsert: true}, callback);
};

module.exports = mongoose.model('PayZenTransactionId', payZenTransactionIdSchema);