Upgrade aes-decrypter to use webcrypto for HLSe decryption where available. (#777)

* Use 'decrypt' with callback instead of Decrypter directly

Cast request.response ArrayBuffer to Uint8Array for explicit passing to
decrypt

* Fix text with Uint8Array key result

* fix test for decrypting (#1)

* s/var/let/

* Upgrade aes-decrypter to ^2.0.0

package.json

@@ -89,7 +89,7 @@
     "test/"
   ],
   "dependencies": {
-    "aes-decrypter": "^1.0.3",
+    "aes-decrypter": "^2.0.0",
     "global": "^4.3.0",
     "m3u8-parser": "^1.0.2",
     "mux.js": "^3.0.0",

src/segment-loader.js

@@ -5,8 +5,8 @@ import Ranges from './ranges';
 import {getMediaIndexForTime_ as getMediaIndexForTime, duration} from './playlist';
 import videojs from 'video.js';
 import SourceUpdater from './source-updater';
-import {Decrypter} from 'aes-decrypter';
 import mp4probe from 'mux.js/lib/mp4/probe';
+import {decrypt} from 'aes-decrypter';
 import Config from './config';
 import window from 'global/window';
 
@@ -706,7 +706,6 @@ export default class SegmentLoader extends videojs.EventTarget {
     let segmentInfo;
     let segment;
     let keyXhrRequest;
-    let view;
 
     // timeout of previously aborted request
     if (!this.xhr_ ||
@@ -789,13 +788,7 @@ export default class SegmentLoader extends videojs.EventTarget {
         return this.trigger('error');
       }
 
-      view = new DataView(request.response);
-      segment.key.bytes = new Uint32Array([
-        view.getUint32(0),
-        view.getUint32(4),
-        view.getUint32(8),
-        view.getUint32(12)
-      ]);
+      segment.key.bytes = new Uint8Array(request.response);
 
       // if the media sequence is greater than 2^32, the IV will be incorrect
       // assuming 10s segments, that would be about 1300 years
@@ -857,14 +850,14 @@ export default class SegmentLoader extends videojs.EventTarget {
       // this is an encrypted segment
       // incrementally decrypt the segment
       /* eslint-disable no-new, handle-callback-err */
-      new Decrypter(segmentInfo.encryptedBytes,
-                    segment.key.bytes,
-                    segment.key.iv,
-                    (function(err, bytes) {
-                      // err always null
-                      segmentInfo.bytes = bytes;
-                      this.handleSegment_();
-                    }).bind(this));
+      decrypt(segmentInfo.encryptedBytes,
+              segment.key.bytes,
+              segment.key.iv,
+              (function(err, bytes) {
+                // err always null
+                segmentInfo.bytes = bytes;
+                this.handleSegment_();
+              }).bind(this));
       /* eslint-enable */
     } else {
       this.handleSegment_();

test/segment-loader.test.js

@@ -913,7 +913,11 @@ QUnit.test('the key is saved to the segment in the correct format', function() {
   segment = segmentInfo.playlist.segments[segmentInfo.mediaIndex];
 
   QUnit.deepEqual(segment.key.bytes,
-                  new Uint32Array([0, 0x01000000, 0x02000000, 0x03000000]),
+                  new Uint8Array([
+                    0x00, 0x00, 0x00, 0x00,
+                    0x01, 0x00, 0x00, 0x00,
+                    0x02, 0x00, 0x00, 0x00,
+                    0x03, 0x00, 0x00, 0x00]),
                   'passed the specified segment key');
 
   // verify stats
@@ -955,19 +959,25 @@ function() {
   QUnit.equal(loader.mediaRequests, 1, '1 request');
 });
 
-QUnit.test('segment with key has decrypted bytes appended during processing', function() {
+QUnit.test('segment with key has decrypted bytes appended during processing', function(assert) {
   let keyRequest;
   let segmentRequest;
 
+  let doneDecrypting = assert.async();
+
   // stop processing so we can examine segment info
-  loader.handleSegment_ = function() {};
+  loader.handleSegment_ = function() {
+    QUnit.ok(loader.pendingSegment_.bytes, 'decrypted bytes in segment');
+    doneDecrypting();
+  };
 
   loader.playlist(playlistWithDuration(10, {isEncrypted: true}));
   loader.mimeType(this.mimeType);
   loader.load();
 
   segmentRequest = this.requests.pop();
-  segmentRequest.response = new Uint8Array(8).buffer;
+  // this response is [0, 1, 2, 3, 4, 5, 6, 7] encrypted
+  segmentRequest.response = new Uint8Array([60, 15, 94, 17, 13, 247, 26, 97, 97, 236, 17, 188, 250, 16, 52, 39]).buffer;
   segmentRequest.respond(200, null, '');
   QUnit.ok(loader.pendingSegment_.encryptedBytes, 'encrypted bytes in segment');
   QUnit.ok(!loader.pendingSegment_.bytes, 'no decrypted bytes in segment');
@@ -980,10 +990,9 @@ QUnit.test('segment with key has decrypted bytes appended during processing', fu
   this.clock.tick(1);
   // Allow the decrypter's async stream to run the callback
   this.clock.tick(1);
-  QUnit.ok(loader.pendingSegment_.bytes, 'decrypted bytes in segment');
 
   // verify stats
-  QUnit.equal(loader.mediaBytesTransferred, 8, '8 bytes');
+  QUnit.equal(loader.mediaBytesTransferred, 16, '16 bytes');
   QUnit.equal(loader.mediaRequests, 1, '1 request');
 });