fix(MSS): Add parsing of PIFF Sample Encryption Box

Closes shaka-project#5390
unext-wendong · Jul 24, 2023 · d2a772b · d2a772b
1 parent c378e10
commit d2a772b
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Showing 3 changed files with 48 additions and 4 deletions.
diff --git a/externs/isoboxer.js b/externs/isoboxer.js
@@ -45,6 +45,7 @@ var ISOBoxerUtils;
 
 /**
  * @typedef {{
+ *   _parsing: boolean,
  *   type: string,
  *   size: number,
  *   _parent: ISOBox,
@@ -123,6 +124,7 @@ var ISOBoxerUtils;
  *   sample_info_size: Array.<number>,
  *   data_offset: number
  * }}
+ * @property {boolean} _parsing
  * @property {string} type
  * @property {number} size
  * @property {ISOBox} _parent

diff --git a/lib/mss/content_protection.js b/lib/mss/content_protection.js
@@ -170,12 +170,22 @@ shaka.mss.ContentProtection = class {
    * @private
    */
   static getKID_(xml) {
+    const Uint8ArrayUtils = shaka.util.Uint8ArrayUtils;
     // KID element is optional and no more than one is
     // allowed inside the DATA element.
     for (const elem of xml.getElementsByTagName('DATA')) {
       const kid = shaka.util.XmlUtils.findChild(elem, 'KID');
       if (kid) {
-        return kid.textContent;
+        // GUID: [DWORD, WORD, WORD, 8-BYTE]
+        const guidBytes = Uint8ArrayUtils.fromBase64(kid.textContent);
+        // Reverse byte order from little-endian to big-endian
+        const kidBytes = new Uint8Array([
+          guidBytes[3], guidBytes[2], guidBytes[1], guidBytes[0],
+          guidBytes[5], guidBytes[4],
+          guidBytes[7], guidBytes[6],
+          ...guidBytes.slice(8),
+        ]);
+        return Uint8ArrayUtils.toHex(kidBytes);
       }
     }
 
@@ -274,7 +284,7 @@ shaka.mss.ContentProtection = class {
 
     for (let i = 0; i < elements.length; i++) {
       const element = elements[i];
-      const systemID = element.getAttribute('SystemID');
+      const systemID = element.getAttribute('SystemID').toLowerCase();
       const keySystem = keySystemsBySystemId[systemID];
       if (keySystem) {
         const KID = ContentProtection.getPlayReadyKID_(element);

diff --git a/lib/transmuxer/mss_transmuxer.js b/lib/transmuxer/mss_transmuxer.js
@@ -98,14 +98,16 @@ shaka.transmuxer.MssTransmuxer = class {
       }
     });
     // eslint-disable-next-line no-restricted-syntax
-    this.isoBoxer_.addBoxProcessor('senc', function() {
+    const sencProcessor = function() {
       // eslint-disable-next-line no-invalid-this
       const box = /** @type {!ISOBox} */(this);
       box._procFullBox();
-      box._procField('sample_count', 'uint', 32);
       if (box.flags & 1) {
+        box._procField('AlgorithmID', 'uint', 24);
         box._procField('IV_size', 'uint', 8);
+        box._procFieldArray('KID', 16, 'uint', 8);
       }
+      box._procField('sample_count', 'uint', 32);
       // eslint-disable-next-line no-restricted-syntax
       box._procEntries('entry', box.sample_count, function(entry) {
         // eslint-disable-next-line no-invalid-this
@@ -125,6 +127,28 @@ shaka.transmuxer.MssTransmuxer = class {
               });
         }
       });
+    };
+    this.isoBoxer_.addBoxProcessor('senc', sencProcessor);
+    // eslint-disable-next-line no-restricted-syntax
+    this.isoBoxer_.addBoxProcessor('uuid', function() {
+      const MssTransmuxer = shaka.transmuxer.MssTransmuxer;
+      // eslint-disable-next-line no-invalid-this
+      const box = /** @type {!ISOBox} */(this);
+      let isSENC = true;
+      for (let i = 0; i < 16; i++) {
+        if (box.usertype[i] !== MssTransmuxer.UUID_SENC_[i]) {
+          isSENC = false;
+        }
+        // Add support for other user types here
+      }
+
+      if (isSENC) {
+        if (box._parsing) {
+          box.type = 'sepiff'; // Rename it to be recognized later
+        }
+        // eslint-disable-next-line no-restricted-syntax, no-invalid-this
+        sencProcessor.call(/** @type {!ISOBox} */(this));
+      }
     });
   }
 
@@ -345,6 +369,14 @@ shaka.transmuxer.MssTransmuxer = class {
   }
 };
 
+/**
+ * @private {!Uint8Array}
+ */
+shaka.transmuxer.MssTransmuxer.UUID_SENC_ = new Uint8Array([
+  0xA2, 0x39, 0x4F, 0x52, 0x5A, 0x9B, 0x4F, 0x14,
+  0xA2, 0x44, 0x6C, 0x42, 0x7C, 0x64, 0x8D, 0xF4,
+]);
+
 shaka.transmuxer.TransmuxerEngine.registerTransmuxer(
     'mss/audio/mp4',
     () => new shaka.transmuxer.MssTransmuxer('mss/audio/mp4'),