EME Logger

Inject EME interface and log its function calls.

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         EME Logger
// @namespace    http://greasyfork.org/
// @version      2.0
// @description  Inject EME interface and log its function calls.
// @author       cramer
// @match        *://*/*
// @run-at       document-start
// @grant        GM_getValue
// @grant        GM_setValue
// @grant        GM_registerMenuCommand
// ==/UserScript==

(async () => {
    const disabledKeySystems = GM_getValue('disabledKeySystems', []);

    const commonKeySystems = {
        'Widevine': /widevine/i,
        'PlayReady': /playready/i,
        'FairPlay': /fairplay|fps/i,
        'ClearKey': /clearkey/i,
    };
    for (const [keySystem, rule] of Object.entries(commonKeySystems)) {
        if (disabledKeySystems.indexOf(keySystem) >= 0) {
            GM_registerMenuCommand(`Enable ${keySystem} (and refresh)`, function() {
                GM_setValue('disabledKeySystems', disabledKeySystems.filter(k => k !== keySystem));
                location.reload();
            });
        } else {
            GM_registerMenuCommand(`Disable ${keySystem} (and refresh)`, function() {
                GM_setValue('disabledKeySystems', [...disabledKeySystems, keySystem]);
                location.reload();
            });
        }
    }

    function isKeySystemDisabled(keySystem) {
        for (const disabledKeySystem of disabledKeySystems) {
            if (keySystem.match(commonKeySystems[disabledKeySystem])) return true;
        }
        return false
    }

    // Color constants
    const $ = {
        INFO: '#66d9ef',
        VALUE: '#4ec9a4',
        METHOD: '#569cd6',
        SUCCESS: '#a6e22e',
        FAILURE: '#6d1212',
        WARNING: '#fd971f',
    };

    const indent = (s,n=4) => s.split('\n').map(l=>Array(n).fill(' ').join('')+l).join('\n');

    const b64 = {
        decode: s => Uint8Array.from(atob(s), c => c.charCodeAt(0)),
        encode: b => btoa(String.fromCharCode(...new Uint8Array(b)))
    };

    const fnproxy = (object, func) => new Proxy(object, { apply: func });

    const proxy = (object, key, func) => Object.hasOwnProperty.call(object, key) && Object.defineProperty(object, key, {
        value: fnproxy(object[key], func)
    });

    function messageHandler(event) {
        const keySession = event.target;
        const {sessionId} = keySession;
        const {message, messageType} = event;
        const listeners = keySession.getEventListeners('message').filter(l => l !== messageHandler);
        console.groupCollapsed(
            `%c[EME] (EVENT)%c MediaKeySession::message%c\n` +
            `Session ID: %c%s%c\n` +
            `Message Type: %c%s%c\n` +
            `Message: %c%s%c\n` +
            `Listeners:`,

            `color: ${$.INFO}; font-weight: bold;`, `color: ${$.METHOD};`, `font-weight: normal;`,
            `color: ${$.VALUE}; font-weight: bold;`, sessionId || '(not available)', `color: inherit; font-weight: normal;`,
            `color: ${$.VALUE}; font-weight: bold;`, messageType, `color: inherit; font-weight: normal;`,
            `font-weight: bold;`, b64.encode(message), `font-weight: normal;`,
            listeners,
        );
        console.trace();
        console.groupEnd();
    }

    function keyStatusColor(status) {
        switch(status.toLowerCase()) {
            case 'usable':
                return $.SUCCESS;
            case 'output-restricted':
            case 'output-downscaled':
            case 'usable-in-future':
            case 'status-pending':
                return $.WARNING;
            case 'expired':
            case 'released':
            case 'internal-error':
            default:
                return $.FAILURE;
        }

    }

    function keystatuseschangeHandler(event) {
        const keySession = event.target;
        const {sessionId} = keySession;
        const listeners = keySession.getEventListeners('keystatuseschange').filter(l => l !== keystatuseschangeHandler);
        let keysFmt = '';
        const keysText = [];
        keySession.keyStatuses.forEach((status, keyId) => {
            keysFmt += `    %c[%s]%c %s%c\n`;
            keysText.push(
                `color: ${keyStatusColor(status)}; font-weight: bold;`,
                status.toUpperCase(),
                `color: ${$.VALUE};`,
                b64.encode(keyId),
                `color: inherit; font-weight: normal;`,
            );
        });
        console.groupCollapsed(
            `%c[EME] (EVENT)%c MediaKeySession::keystatuseschange%c\n` +
            `Session ID: %c%s%c\n` +
            `Key Statuses:\n` + keysFmt +
            'Listeners:',

            `color: ${$.INFO}; font-weight: bold;`, `color: ${$.METHOD};`, `font-weight: normal;`,
            `color: ${$.VALUE}; font-weight: bold;`, sessionId || '(not available)', `color: inherit; font-weight: normal;`,
            ...keysText,
            listeners,
        );
        console.trace();
        console.groupEnd();
    }

    function getEventListeners(type) {
        if (this == null) return [];
        const store = this[Symbol.for(getEventListeners)];
        if (store == null || store[type] == null) return [];
        return store[type];
    }

    EventTarget.prototype.getEventListeners = getEventListeners;

    typeof Navigator !== 'undefined' && proxy(Navigator.prototype, 'requestMediaKeySystemAccess', async (_target, _this, _args) => {
        const [keySystem, supportedConfigurations] = _args;
        const enterMessage = [
            `%c[EME] (CALL)%c Navigator::requestMediaKeySystemAccess%c\n` +
            `Key System: %c%s%c\n` +
            `Supported Configurations:\n`,

            `color: ${$.INFO}; font-weight: bold;`, `color: ${$.METHOD};`, `font-weight: normal;`,
            `color: ${$.VALUE}; font-weight: bold;`, keySystem, `color: inherit; font-weight: normal;`,
            indent(JSON.stringify(supportedConfigurations, null, '    ')),
        ];
        let result, err;
        try {
            if (isKeySystemDisabled(keySystem)) {
                throw new DOMException(`Unsupported keySystem or supportedConfigurations.`, `NotSupportedError`);
            }
            result = await _target.apply(_this, _args);
            return result;
        } catch(e) {
            err = e;
            throw e;
        } finally {
            console.groupCollapsed(...enterMessage);
            if (err) {
                console.error(`%c[FAILURE]`, `color: ${$.FAILURE}; font-weight: bold;`, err);
            } else {
                console.log(`%c[SUCCESS]`, `color: ${$.SUCCESS}; font-weight: bold;`, result);
            }
            console.trace();
            console.groupEnd();
        }
    });

    typeof MediaKeySystemAccess !== 'undefined' && proxy(MediaKeySystemAccess.prototype, 'createMediaKeys', async (_target, _this, _args) => {
        const enterMessage = [
            `%c[EME] (CALL)%c MediaKeySystemAccess::createMediaKeys%c\n` +
            `Key System: %c%s%c\n` +
            `Configurations:\n`,

            `color: ${$.INFO}; font-weight: bold;`, `color: ${$.METHOD};`, `font-weight: normal;`,
            `color: ${$.VALUE}; font-weight: bold;`, _this.keySystem, `color: inherit; font-weight: normal;`,
            indent(JSON.stringify(_this.getConfiguration(), null, '    ')),
        ];
        let result, err;
        try {
            result = await _target.apply(_this, _args);
            return result;
        } catch(e) {
            err = e;
            throw e;
        } finally {
            console.groupCollapsed(...enterMessage);
            if (err) {
                console.error(`%c[FAILURE]`, `color: ${$.FAILURE}; font-weight: bold;`, err);
            } else {
                console.log(`%c[SUCCESS]`, `color: ${$.SUCCESS}; font-weight: bold;`, result);
            }
            console.trace();
            console.groupEnd();
        }
    });

    if (typeof MediaKeys !== 'undefined') {
        proxy(MediaKeys.prototype, 'setServerCertificate', async (_target, _this, _args) => {
            const [serverCertificate] = _args;
            const enterMessage = [
                `%c[EME] (CALL)%c MediaKeys::setServerCertificate%c\n` +
                `Server Certificate:`,

                `color: ${$.INFO}; font-weight: bold;`, `color: ${$.METHOD};`, `font-weight: normal;`,
                b64.encode(serverCertificate),
            ];
            let result, err;
            try {
                result = await _target.apply(_this, _args);
                return result;
            } catch(e) {
                err = e;
                throw e;
            } finally {
                console.groupCollapsed(...enterMessage);
                if (err) {
                    console.error(`%c[FAILURE]`, `color: ${$.FAILURE}; font-weight: bold;`, err);
                } else {
                    console.log(`%c[SUCCESS]`, `color: ${$.SUCCESS}; font-weight: bold;`, result);
                }
                console.trace();
                console.groupEnd();
            }
        });

        proxy(MediaKeys.prototype, 'createSession', (_target, _this, _args) => {
            const [sessionType] = _args;
            const enterMessage = [
                `%c[EME] (CALL)%c MediaKeys::createSession%c\n` +
                `Session Type: %c%s`,

                `color: ${$.INFO}; font-weight: bold;`, `color: ${$.METHOD};`, `font-weight: normal;`,
                `color: ${$.VALUE}; font-weight: bold;`, sessionType || 'temporary (default)',
            ];
            let session, err;
            try {
                session = _target.apply(_this, _args);
                session.addEventListener('message', messageHandler);
                session.addEventListener('keystatuseschange', keystatuseschangeHandler);
                return session;
            } catch(e) {
                err = e;
                throw e;
            } finally {
                console.groupCollapsed(...enterMessage);
                if (err) {
                    console.error(`%c[FAILURE]`, `color: ${$.FAILURE}; font-weight: bold;`, err);
                } else {
                    console.log(`%c[SUCCESS]`, `color: ${$.SUCCESS}; font-weight: bold;`, session);
                }
                console.trace();
                console.groupEnd();
            }
        });
    }

    if (typeof EventTarget !== 'undefined') {
        proxy(EventTarget.prototype, 'addEventListener', async (_target, _this, _args) => {
            if (_this != null) {
                const [type, listener] = _args;
                const storeKey = Symbol.for(getEventListeners);
                if (!(storeKey in _this)) _this[storeKey] = {};
                const store = _this[storeKey];
                if (!(type in store)) store[type] = [];
                const listeners = store[type];
                if (listeners.indexOf(listener) < 0) {
                    listeners.push(listener);
                }
            }
            return _target.apply(_this, _args);
        });

        proxy(EventTarget.prototype, 'removeEventListener', async (_target, _this, _args) => {
            if (_this != null) {
                const [type, listener] = _args;
                const storeKey = Symbol.for(getEventListeners);
                if (!(storeKey in _this)) return;
                const store = _this[storeKey];
                if (!(type in store)) return;
                const listeners = store[type];
                const index = listeners.indexOf(listener);
                if (index >= 0) {
                    if (listeners.length === 1) {
                        delete store[type];
                    } else {
                        listeners.splice(index, 1);
                    }
                }
            }
            return _target.apply(_this, _args);
        });
    }

    if (typeof MediaKeySession !== 'undefined') {
        proxy(MediaKeySession.prototype, 'generateRequest', async (_target, _this, _args) => {
            const [initDataType, initData] = _args;
            const enterMessage = [
                `%c[EME] (CALL)%c MediaKeySession::generateRequest%c\n` +
                `Session ID: %c%s%c\n` +
                `Init Data Type: %c%s%c\n` +
                `Init Data:`,

                `color: ${$.INFO}; font-weight: bold;`, `color: ${$.METHOD};`, `font-weight: normal;`,
                `color: ${$.VALUE}; font-weight: bold;`, _this.sessionId || '(not available)', `color: inherit; font-weight: normal;`,
                `color: ${$.VALUE}; font-weight: bold;`, initDataType, `color: inherit; font-weight: normal;`,
                b64.encode(initData),
            ];
            let result, err;
            try {
                result = await _target.apply(_this, _args);
                return result;
            } catch(e) {
                err = e;
                throw e;
            } finally {
                console.groupCollapsed(...enterMessage);
                if (err) {
                    console.error(`%c[FAILURE]`, `color: ${$.FAILURE}; font-weight: bold;`, err);
                } else {
                    console.log(`%c[SUCCESS]`, `color: ${$.SUCCESS}; font-weight: bold;`, result);
                }
                console.trace();
                console.groupEnd();
            }
        });

        proxy(MediaKeySession.prototype, 'load', async (_target, _this, _args) => {
            const [sessionId] = _args;
            const enterMessage = [
                `%c[EME] (CALL)%c MediaKeySession::load%c\n` +
                `Session ID: %c%s`,

                `color: ${$.INFO}; font-weight: bold;`, `color: ${$.METHOD};`, `font-weight: normal;`,
                `color: ${$.VALUE}; font-weight: bold;`, _this.sessionId || '(not available)',
            ];
            let result, err;
            try {
                result = await _target.apply(_this, _args);
                return result;
            } catch(e) {
                err = e;
                throw e;
            } finally {
                console.groupCollapsed(...enterMessage);
                if (err) {
                    console.error(`%c[FAILURE]`, `color: ${$.FAILURE}; font-weight: bold;`, err);
                } else {
                    console.log(`%c[SUCCESS]`, `color: ${$.SUCCESS}; font-weight: bold;`, result);
                }
                console.trace();
                console.groupEnd();
            }
        });

        proxy(MediaKeySession.prototype, 'update', async (_target, _this, _args) => {
            const [response] = _args;
            const enterMessage = [
                `%c[EME] (CALL)%c MediaKeySession::update%c\n` +
                `Session ID: %c%s%c\n` +
                `Response:`,

                `color: ${$.INFO}; font-weight: bold;`, `color: ${$.METHOD};`, `font-weight: normal;`,
                `color: ${$.VALUE}; font-weight: bold;`, _this.sessionId || '(not available)', `color: inherit; font-weight: normal;`,
                b64.encode(response),
            ];
            let err;
            try {
                return await _target.apply(_this, _args);
            } catch(e) {
                err = e;
                throw e;
            } finally {
                console.groupCollapsed(...enterMessage);
                if (err) {
                    console.error(`%c[FAILURE]`, `color: ${$.FAILURE}; font-weight: bold;`, err);
                } else {
                    console.log(`%c[SUCCESS]`, `color: ${$.SUCCESS}; font-weight: bold;`);
                }
                console.trace();
                console.groupEnd();
            }
        });

        proxy(MediaKeySession.prototype, 'close', async (_target, _this, _args) => {
            const enterMessage = [
                `%c[EME] (CALL)%c MediaKeySession::close%c\n` +
                `Session ID: %c%s`,

                `color: ${$.INFO}; font-weight: bold;`, `color: ${$.METHOD};`, `font-weight: normal;`,
                `color: ${$.VALUE}; font-weight: bold;`, _this.sessionId || '(not available)',
            ];
            let err;
            try {
                return await _target.apply(_this, _args);
            } catch(e) {
                err = e;
                throw e;
            } finally {
                console.groupCollapsed(...enterMessage);
                if (err) {
                    console.error(`%c[FAILURE]`, `color: ${$.FAILURE}; font-weight: bold;`, err);
                } else {
                    console.log(`%c[SUCCESS]`, `color: ${$.SUCCESS}; font-weight: bold;`);
                }
                console.trace();
                console.groupEnd();
            }
        });

        proxy(MediaKeySession.prototype, 'remove', async (_target, _this, _args) => {
            const enterMessage = [
                `%c[EME] (CALL)%c MediaKeySession::remove%c\n` +
                `Session ID: %c%s`,

                `color: ${$.INFO}; font-weight: bold;`, `color: ${$.METHOD};`, `font-weight: normal;`,
                `color: ${$.VALUE}; font-weight: bold;`, _this.sessionId || '(not available)',
            ];
            let err;
            try {
                return await _target.apply(_this, _args);
            } catch(e) {
                err = e;
                throw e;
            } finally {
                console.groupCollapsed(...enterMessage);
                if (err) {
                    console.error(`%c[FAILURE]`, `color: ${$.FAILURE}; font-weight: bold;`, err);
                } else {
                    console.log(`%c[SUCCESS]`, `color: ${$.SUCCESS}; font-weight: bold;`);
                }
                console.trace();
                console.groupEnd();
            }
        });
    }
})();