Is it possible to decrypt a DRM HLS content in windows?

Question

I have to develop a function that decrypt a DRM HLS content using video.js lib. I've retrieved about this issue and I found it(https://learn.microsoft.com/ko-kr/azure/media-services/previous/media-services-protect-hls-with-fairplay) So I've used playready as like as a below

const setPlayerForDashHLS = (src, type, key, licenseURL) => {
                    const customData = DRM_TYPE + SITE_ID + key;

                    player.src({
                        src: src,
                        type: type,
                        keySystems: {
                            'com.microsoft.playready': {
                                url: licenseURL,
                                licenseHeaders: {
                                    'pallycon-customdata': customData
                                }
                            }
                        }
                    });
                }

but It's not working to play DRM HLS video and not print anything about an error log. I want to know that how to play it.

Answer 1

There is an official plugin for VideoJS that supports DRM playback, leveraging the EME standard.

EME (Encrypted Media Standard) is a HTML5 extension to support playing encrypted media in a standard way - https://www.w3.org/TR/2017/REC-encrypted-media-20170918/)

You can see the VideoJS plugin here: https://github.com/videojs/videojs-contrib-eme

It includes instructions for configuring and playing back with PlayReady DRM.

Looking at the error message you are receiving:

This is generated by the platform or browser and indicates:

NotSupportedError

Either the specified keySystem isn't supported by the platform or the browser, or none of the configurations specified by supportedConfigurations can be satisfied (if, for example, none of the codecs specified in contentType are available).

(https://developer.mozilla.org/en-US/docs/Web/API/Navigator/requestMediaKeySystemAccess)

Looking at your configuration above, one reason why you might get this could be playing back the video on a browser which does not support PlayReady. As a general (not absolute) rule the DRM's supported 'natively' by browsers and devices are at this time:

• Android devices - Widevine
• Chrome browser - Widevine
• FireFox - Widevine
• iOS device - FairPlay
• Safari browser - FairPlay
• Internet Explorer browser - PlayReady

To try to minimise the overhead for video stream providers CENC (https://en.wikipedia.org/wiki/MPEG_Common_Encryption) allows you have a single stream protected by both PlayReady or Widevine.

Added to this, CMAF and the announced support for AES-CBC mode encryption by all major devices and browsers promises the ability to have a single media stream for encrypted HLS and DASH streams, but it will likely be some time before the announced support rolls out to all devices, meaning that now typically both HLS and DASH streams are typically required for maximum reach for streamed video.

Answer 2

Since you are using Azure Media Services, you already have dynamic packaging - i.e. you can have both HLS and MPEG-DASH output from the same underlying video assets. I would strongly encourage you to use MPEG-DASH if you are trying to play back content in the browser. HLS + PlayReady is only supported on very few devices, whereas MPEG-DASH + PlayReady is supported on pretty much all the places that support PlayReady.

Also, i presume you already work with a vendor for PlayReady DRM, if not the PlayReady and/or Widevine site lists a number of vendors.

Also, you probably want to support Widevine as well, as that is what is supported for playback in Google Chrome and Firefox.

Answer 3

Is it possible to decrypt a DRM HLS content in windows?

I have to develop a function that decrypt [...]

Your question shows misunderstaning about how DRM-enabled playback works.

You cannot decrypt DRM-protected content in Windows in any event. You would need a decryption key and when it comes to decryption, this key is applied in a known, well-defined way. However the key is exactly what you are never given. Especially in Windows, such as in the case of Microsoft PlayReady DRM, compatible browsers are providing decryption service via implementation of EME (Encrypted Media Extensions) specification. Browsers decrypt content on terms that decrypted content is played back subject to additional constraints (pretty restrictive, think of enforced content protected on the physical cable to monitor when you play such content!), and you never get plain decrypted data back in particular.

You can play DRM-protected content with browsers by working collaboratively and playing protected data. But you never decrypt content on your own, such as by implementing a decryption function.