feat(dash): [ClearKey] Changes as per comments.

shaka-project · Apr 13, 2022 · 41025d8 · 41025d8
1 parent c4bea5f
commit 41025d8
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Showing 3 changed files with 38 additions and 56 deletions.
diff --git a/lib/dash/content_protection.js b/lib/dash/content_protection.js
@@ -356,7 +356,10 @@ shaka.dash.ContentProtection = class {
       0x9a, 0x04, 0xf0, 0x79, 0x98, 0x40, 0x42, 0x86,
       0xab, 0x92, 0xe6, 0x5b, 0xe0, 0x88, 0x5f, 0x95,
     ]);
-    const pssh = shaka.util.Pssh.createPssh(data, systemId);
+    const keyIds = new Set();
+    const psshVersion = 0;
+    const pssh =
+        shaka.util.Pssh.createPssh(data, systemId, keyIds, psshVersion);
     return [
       {
         initData: pssh,
@@ -367,7 +370,8 @@ shaka.dash.ContentProtection = class {
   }
 
   /**
-   * Creates ClearKey initData from Default_KID value.
+   * Creates ClearKey initData from Default_KID value retrieved from previously
+   * parsed ContentProtection tag.
    * @param {shaka.dash.ContentProtection.Element} element
    * @param {!Set.<string>} keyIds
    * @return {?Array.<shaka.extern.InitDataOverride>}
@@ -378,16 +382,15 @@ shaka.dash.ContentProtection = class {
       return null;
     }
 
-    const Uint8ArrayUtils = shaka.util.Uint8ArrayUtils;
-    const [first] = keyIds;
-    const data = Uint8ArrayUtils.fromHex(first);
-
     const systemId = new Uint8Array([
       0x10, 0x77, 0xef, 0xec, 0xc0, 0xb2, 0x4d, 0x02,
       0xac, 0xe3, 0x3c, 0x1e, 0x52, 0xe2, 0xfb, 0x4b,
     ]);
+    const data = new Uint8Array([]);
+    const psshVersion = 1;
+    const pssh =
+         shaka.util.Pssh.createPssh(data, systemId, keyIds, psshVersion);
 
-    const pssh = shaka.util.Pssh.createPsshClearKey(data, systemId);
     return [
       {
         initData: pssh,

diff --git a/lib/hls/hls_parser.js b/lib/hls/hls_parser.js
@@ -2529,7 +2529,10 @@ shaka.hls.HlsParser = class {
       0x9a, 0x04, 0xf0, 0x79, 0x98, 0x40, 0x42, 0x86,
       0xab, 0x92, 0xe6, 0x5b, 0xe0, 0x88, 0x5f, 0x95,
     ]);
-    const pssh = shaka.util.Pssh.createPssh(data, systemId);
+    const keyIds = new Set();
+    const psshVersion = 0;
+    const pssh =
+        shaka.util.Pssh.createPssh(data, systemId, keyIds, psshVersion);
     const drmInfo = shaka.util.ManifestParserUtils.createDrmInfo(
         'com.microsoft.playready', [
           {initDataType: 'cenc', initData: pssh},

diff --git a/lib/util/pssh.js b/lib/util/pssh.js
@@ -90,16 +90,22 @@ shaka.util.Pssh = class {
   }
 
   /**
-   * Creates a pssh blob from the given system ID and data.
+   * Creates a pssh blob from the given system ID, data, keyIds and version.
    *
    * @param {!Uint8Array} data
    * @param {!Uint8Array} systemId
+   * @param {!Set.<string>} keyIds
+   * @param {number} version
    * @return {!Uint8Array}
    */
-  static createPssh(data, systemId) {
+  static createPssh(data,
+      systemId, keyIds, version) {
     goog.asserts.assert(systemId.byteLength == 16, 'Invalid system ID length');
     const dataLength = data.length;
-    const psshSize = 0x4 + 0x4 + 0x4 + systemId.length + 0x4 + dataLength;
+    let psshSize = 0x4 + 0x4 + 0x4 + systemId.length + 0x4 + dataLength;
+    if (version > 0) {
+      psshSize += 0x4 + (16 * keyIds.size);
+    }
 
     /** @type {!Uint8Array} */
     const psshBox = new Uint8Array(psshSize);
@@ -111,58 +117,28 @@ shaka.util.Pssh = class {
     byteCursor += 0x4;
     psshData.setUint32(byteCursor, 0x70737368);  // 'pssh'
     byteCursor += 0x4;
-    psshData.setUint32(byteCursor, 0);  // flags
+    (version < 1) ? psshData.setUint32(byteCursor, 0) :
+        psshData.setUint32(byteCursor, 0x01000000); // version + flags
     byteCursor += 0x4;
     psshBox.set(systemId, byteCursor);
     byteCursor += systemId.length;
-    psshData.setUint32(byteCursor, dataLength);
-    byteCursor += 0x4;
-    psshBox.set(data, byteCursor);
-    byteCursor += dataLength;
-
-    goog.asserts.assert(byteCursor === psshSize, 'PSSH invalid length.');
-    return psshBox;
-  }
-
-  /**
-   * Creates a ClearKey cenc pssh blob from the given system ID and data.
-   * Data will contain one key id.
-   * Based on https://www.w3.org/TR/eme-initdata-cenc/
-   * @param {!Uint8Array} data
-   * @param {!Uint8Array} systemId
-   * @return {!Uint8Array}
-   */
-  static createPsshClearKey(data, systemId) {
-    goog.asserts.assert(systemId.byteLength == 16, 'Invalid system ID length');
-    const dataLength = data.length;
-    const psshSize = 0x4 +              // pssh size (4 bytes)
-                     0x4 +              // 'pssh' (4 bytes)
-                     0x4 +              // version (1 byte) + flags (3 bytes)
-                     systemId.length +  // system id (16 bytes)
-                     0x4 +              // KID count (4 bytes)
-                     dataLength +       // KID value (16 bytes)
-                     0x4;               // size of data (4 bytes)
 
-    /** @type {!Uint8Array} */
-    const psshBox = new Uint8Array(psshSize);
-    /** @type {!DataView} */
-    const psshData = shaka.util.BufferUtils.toDataView(psshBox);
+    // if version > 0, add KID count and kid values.
+    if (version > 0) {
+      psshData.setUint32(byteCursor, keyIds.size); // KID_count
+      byteCursor += 0x4;
+      const Uint8ArrayUtils = shaka.util.Uint8ArrayUtils;
+      for (const keyId of keyIds) {
+        const KID = Uint8ArrayUtils.fromHex(keyId);
+        psshBox.set(KID, byteCursor);
+        byteCursor += KID.length;
+      }
+    }
 
-    let byteCursor = 0;
-    psshData.setUint32(byteCursor, psshSize);
-    byteCursor += 0x4;
-    psshData.setUint32(byteCursor, 0x70737368);  // 'pssh'
-    byteCursor += 0x4;
-    psshData.setUint32(byteCursor, 0x01000000);  // version = 1
-    byteCursor += 0x4;
-    psshBox.set(systemId, byteCursor);
-    byteCursor += systemId.length;
-    psshData.setUint32(byteCursor, 0x00000001); // KID_count
+    psshData.setUint32(byteCursor, dataLength);
     byteCursor += 0x4;
-    psshBox.set(data, byteCursor); // add kid
+    psshBox.set(data, byteCursor);
     byteCursor += dataLength;
-    psshData.setUint32(byteCursor, 0x00000000);
-    byteCursor += 0x4;
 
     goog.asserts.assert(byteCursor === psshSize, 'PSSH invalid length.');
     return psshBox;