Inline ClearKey Viewer

Outputs clearkey in the console for videos using the ClearKey DRM
Ask a question, post a review, or report the script.
Wrap lines
// ==UserScript==
// @name         Inline ClearKey Viewer
// @namespace    https://mirazmac.com/
// @version      1.0.0
// @description  Outputs clearkey in the console for videos using the ClearKey DRM
// @author       Miraz Mac
// @match        https://*/*
// @license      MIT
// @icon         https://www.google.com/s2/favicons?sz=64&domain=dashif.org
// @run-at       document-start
// ==/UserScript==

(function() {
    'use strict';


    const b64ToHex = b64 => [...atob(b64)].map(c=> c.charCodeAt(0).toString(16).padStart(2,0)).join``


    function getClearkey(response) {
        let obj;

        try {
            obj = JSON.parse(new TextDecoder().decode(response));
        } catch {
            return null;
        }

        if (!Array.isArray(obj.keys)) {
            return null;
        }

        return obj.keys
            .map(o => [o.kid, o.k])
            .map(o => o.map(a => a.replace(/-/g, '+').replace(/_/g, '/') + "=="))
            .map(o => `${b64ToHex(o[0])}:${b64ToHex(o[1])}`)
            .join("\n");
    }


    const originalUpdate = MediaKeySession.prototype.update;
    MediaKeySession.prototype.update = function(response) {
        const result = originalUpdate.call(this, response);

        try {
            const keys = getClearkey(response);
            if (!keys) return result;

            console.log("[CLEARKEY]", keys);
            document.dispatchEvent(new CustomEvent("clearkey", {
                detail: keys
            }));
        } finally {
            return result;
        }
    };



})();