From 19e24b1d741b4ba6946011748be8b759b4b71773 Mon Sep 17 00:00:00 2001
From: sr90 <sr1990003@gmail.com>
Date: Wed, 30 Mar 2022 09:10:14 -0700
Subject: [PATCH] feat(dash): Parse ClearKey license URL in MPD (#4066)

Example content protection tags parsed:

```xml
<ContentProtection schemeIdUri="urn:mpeg:dash:mp4protection:2011" value="cenc" cenc:default_KID="<default key id>" />
<ContentProtection value="ClearKey1.0" schemeIdUri="urn:uuid:e2719d58-a985-b3c9-781a-b030af78d30e">
    <clearkey:Laurl Lic_type="EME-1.0">License Url</clearkey:Laurl>
```

The player parses the default key id and license url,
and sends a POST request to license url as per https://w3c.github.io/encrypted-media/#clear-key-request-format to retrieve the decryption key/s.
---
 AUTHORS                                       |  1 +
 CONTRIBUTORS                                  |  1 +
 lib/dash/content_protection.js                | 32 +++++++++++++-
 lib/util/player_configuration.js              |  2 +
 .../dash_parser_content_protection_unit.js    | 44 +++++++++++++++++++
 5 files changed, 79 insertions(+), 1 deletion(-)

diff --git a/AUTHORS b/AUTHORS
index f4402639d5..7f65582102 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -67,6 +67,7 @@ Rostislav Hejduk <Ross-cz@users.noreply.github.com>
 SameGoal Inc. <*@samegoal.com>
 Sanborn Hilland <sanbornh@rogers.com>
 Sander Saares <sander@saares.eu>
+Sanil Raut <sr1990003@gmail.com>
 Swank Motion Pictures Inc. <*@swankmp.com>
 TalkTalk Plc <*@talktalkplc.com>
 Tatsiana Gelahova <tatsiana.gelahova@gmail.com>
diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index e83fd31d18..26c5952226 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -97,6 +97,7 @@ Sam Dutton <dutton@google.com>
 Sanborn Hilland <sanbornh@rogers.com>
 Sander Saares <sander@saares.eu>
 Sandra Lokshina <ismena@google.com>
+Sanil Raut <sr1990003@gmail.com>
 Satheesh Velmurugan <satheesh@philo.com>
 Semih Gokceoglu <semih.gkcoglu@gmail.com>
 Seth Madison <seth@philo.com>
diff --git a/lib/dash/content_protection.js b/lib/dash/content_protection.js
index 8165a6fc94..8e3fe75b39 100644
--- a/lib/dash/content_protection.js
+++ b/lib/dash/content_protection.js
@@ -180,6 +180,27 @@ shaka.dash.ContentProtection = class {
     return '';
   }
 
+  /**
+   * Gets a ClearKey license URL from a content protection element
+   * containing a custom `clearkey::Laurl` element
+   *
+   * @param {shaka.dash.ContentProtection.Element} element
+   * @return {string}
+   */
+  static getClearKeyLicenseUrl(element) {
+    const clearKeyLaurlNode = shaka.util.XmlUtils.findChildNS(
+        element.node, shaka.dash.ContentProtection.ClearKeyNamespaceUri_,
+        'Laurl',
+    );
+    if (clearKeyLaurlNode &&
+      clearKeyLaurlNode.getAttribute('Lic_type') === 'EME-1.0') {
+      if (clearKeyLaurlNode.textContent) {
+        return clearKeyLaurlNode.textContent;
+      }
+    }
+    return '';
+  }
+
   /**
    * Parses an Array buffer starting at byteOffset for PlayReady Object Records.
    * Each PRO Record is preceded by its PlayReady Record type and length in
@@ -562,7 +583,9 @@ shaka.dash.ContentProtection.licenseUrlParsers_ = new Map()
     .set('com.microsoft.playready.software',
         shaka.dash.ContentProtection.getPlayReadyLicenseUrl)
     .set('com.microsoft.playready.hardware',
-        shaka.dash.ContentProtection.getPlayReadyLicenseUrl);
+        shaka.dash.ContentProtection.getPlayReadyLicenseUrl)
+    .set('org.w3.clearkey',
+        shaka.dash.ContentProtection.getClearKeyLicenseUrl);
 
 /**
  * @const {string}
@@ -577,3 +600,10 @@ shaka.dash.ContentProtection.MP4Protection_ =
  * @private
  */
 shaka.dash.ContentProtection.CencNamespaceUri_ = 'urn:mpeg:cenc:2013';
+
+/**
+ * @const {string}
+ * @private
+ */
+shaka.dash.ContentProtection.ClearKeyNamespaceUri_ =
+  'http://dashif.org/guidelines/clearKey';
diff --git a/lib/util/player_configuration.js b/lib/util/player_configuration.js
index fe4f5d27e9..d5e37aff52 100644
--- a/lib/util/player_configuration.js
+++ b/lib/util/player_configuration.js
@@ -100,6 +100,8 @@ shaka.util.PlayerConfiguration = class {
         keySystemsByURI: {
           'urn:uuid:1077efec-c0b2-4d02-ace3-3c1e52e2fb4b':
             'org.w3.clearkey',
+          'urn:uuid:e2719d58-a985-b3c9-781a-b030af78d30e':
+            'org.w3.clearkey',
           'urn:uuid:edef8ba9-79d6-4ace-a3c8-27dcd51d21ed':
             'com.widevine.alpha',
           'urn:uuid:9a04f079-9840-4286-ab92-e65be0885f95':
diff --git a/test/dash/dash_parser_content_protection_unit.js b/test/dash/dash_parser_content_protection_unit.js
index f9a046bb9a..093512f74b 100644
--- a/test/dash/dash_parser_content_protection_unit.js
+++ b/test/dash/dash_parser_content_protection_unit.js
@@ -814,6 +814,50 @@ describe('DashParser ContentProtection', () => {
     });
   });
 
+  describe('getClearKeyLicenseUrl', () => {
+    it('valid clearkey:Laurl node', () => {
+      const input = {
+        init: null,
+        keyId: null,
+        schemeUri: '',
+        node: strToXml([
+          '<test xmlns:clearkey="http://dashif.org/guidelines/clearKey">',
+          '  <clearkey:Laurl ',
+          '     Lic_type="EME-1.0">www.example.com</clearkey:Laurl>',
+          '</test>',
+        ].join('\n')),
+      };
+      const actual = ContentProtection.getClearKeyLicenseUrl(input);
+      expect(actual).toBe('www.example.com');
+    });
+
+    it('clearkey:Laurl without license url', () => {
+      const input = {
+        init: null,
+        keyId: null,
+        schemeUri: '',
+        node: strToXml([
+          '<test xmlns:clearkey="http://dashif.org/guidelines/clearKey">',
+          '  <clearkey:Laurl Lic_type="EME-1.0"></clearkey:Laurl>',
+          '</test>',
+        ].join('\n')),
+      };
+      const actual = ContentProtection.getClearKeyLicenseUrl(input);
+      expect(actual).toBe('');
+    });
+
+    it('no clearkey:Laurl node', () => {
+      const input = {
+        init: null,
+        keyId: null,
+        schemeUri: '',
+        node: strToXml('<test></test>'),
+      };
+      const actual = ContentProtection.getClearKeyLicenseUrl(input);
+      expect(actual).toBe('');
+    });
+  });
+
   describe('getPlayReadyLicenseURL', () => {
     it('mspro', () => {
       const laurl = [