Bypasses

Configuring your Gift URL

To use the Gift functionality within Zephr you will need to have your Gift URL configured. This is the base URL that is used within the Gift link, and will often be your core website URL.

To set this up, navigate to Settings > CDN and find the Gifts heading under Configuration. Enter the base URL for gift links, then click Save.

Adding a Gift

• Navigate to Entitlement Manger > Gifts
• Click Add Gift
• In the modal that pops up, paste the slug of the page that you wish to grant access to.

• Click Create Gift.

This will generate a link, which can be sent to a user for single use access to the page assigned to the gift.

Once created, a list of unclaimed gifts will be available under Entitlement Manager > Gifts. You can remove these by clicking Delete next to the relevant Gift.

Creating a Trusted Referrer within Zephr

To begin setting up your Trusted Referrers, navigate to Entitlement Manager > Bypasses > Trusted Referrers within the Zephr Admin Console.

Under Configuration > Content Identifier Source choose between Path and Content Id Parameter and click Save.

Following this, you will need to create a secret for the Trusted Referrer you are setting up. For a 3rd party to create a trusted link into a Zephr-proxied site, they will need to be given this secret. Under the Trusted Referrers heading, click Add Trusted Referrer. Set the Referrer Domain for the 3rd party you with to use as a Trusted Referrer. This should be the domain through which traffic will be referred to Zephr. Take note of the Secret, then click Create Trusted Referrer.

Instructing a Trusted Referrer how to create Trusted Links

The Trusted Referrer will need to use server-side code to generate btr tokens in order to create trusted links to your site.

The btr token for a particular link is obtained by using MD5 to hash the path part of the link together with the Trusted Referrer’s Secret (set up above), separated by a pipe ‘|’ symbol. Fortunately this is trivial in most server-side languages.

For example, for the website trusted-forum.biz – which has been given Secret 89b4c0e4-e95f-4981-b872-b85ea5aec0ff -the following code snippets will all generate a valid link to http://your-website.com/stories/article228.html

Java

public String createBTRToken(String path, String secret) {
    try {
        return DatatypeConverter.printHexBinary(MessageDigest.getInstance("MD5").digest((path + "|" + secret).getBytes(StandardCharsets.UTF_8);
    } catch (Exception e) {
        return "";
    }
}

String trustedLink = "https://www.your-website.com/stories/article228.html?btr=" + createBTRToken("/stories/article228.html", "89b4c0e4-e95f-4981-b872-b85ea5aec0ff");

PHP

<?php echo 'https://www.your-website.com/stories/article228.html?btr=' . md5('/stories/article228.html|89b4c0e4-e95f-4981-b872-b85ea5aec0ff') ?>

Javascript (node.js server-side)

// assumes md5 was installed with npm install md5

var md5 = require('md5');

var trustedLink = 'https://www.your-website.com?btr=' + md5('/stories/article228.html' + | + '89b4c0e4-e95f-4981-b872-b85ea5aec0ff');

NOTE: It is important that the Trusted Referrer uses client-side javascript to generate Trusted Links – otherwise it will be possible for tech-savvy users to create their own trusted links and spoof the Referer header to gain free access to any content.