DRM license wrapping in JSON

[jakubvojacek]

We are planning to move from shaka player to dashjs for live content due to missing support of what shaka team calls "encoder drift" (shaka-project/shaka-player#999).

However, we are using widevine and license & response wrapping (for shaka it's nicely described here https://shaka-player-demo.appspot.com/docs/api/tutorial-license-wrapping.html). Basically, we need to send authentication header in each license / renewal request and both the request and response should be wrapped in JSON.

My understanding is that the header can be set as following:

player.setProtectionData({
	"com.widevine.alpha": {
	    "serverURL": "https://test...",
	    "httpRequestHeaders": {
	        "Authorization": licenseToken
	    }
	}
});

Is there a way to also be able send the request as JSON and receive it as JSON?

Thank you

[epiclabsDASH]

@jakubvojacek, we are taking a look and will come back to you shortly with the best way of achieving this (license wrapping in json) in dash.js. Thanks for the patience.

[jakubvojacek]

@epiclabsDASH thank you, will stay tuned 👍

[jakubvojacek]

@epiclabsDASH any update on the feature request above? Do you need some examples of what I mean?

Thank you

[jakubvojacek]

To clarify, this is how should the license request look like, for example:

{"profiles_id":10,"channels_id":20,"rawLicense":"CAESxx..."}

and this is how the license response looks like

{"rawLicense":"CAIS+QoKKgoQn2esM9iZ+hQMpyfR....","additional_data":{}}

Do you think something like this would be possible?

Thank you

[Achibana]

You can overwrite the getLicenseRequestFromMessage of keySystem to wrapper the request and unwrapper the response in getLicenseMessage in Servers.

[el-gringo]

@Achibana

Hi, I have been able to wrap my license request, but I did not find a way to unwrap the response from the server.
Here is the way I did it:

const player = dashjs.MediaPlayer().create();
player.initialize(video, null, true);
player.setProtectionData({
    "com.widevine.alpha": {
        serverURL: WIDEVINE_LICENSE_URL,
        httpRequestHeaders: {
            "Authorization": "Bearer " + authenticationToken
        },
        withCredentials: false
    }
});

player.on(dashjs.MediaPlayer.events.KEY_SYSTEM_SELECTED, e => {
    e.data.keySystem.getLicenseRequestFromMessage = challenge => {
        const wrapper = {
            licenseRequest: base64Encode(challenge),
            ...otherData
        };
        const wrappedJson = JSON.stringify(wrapped);
        return wrappedJson;
    }
}

[Achibana]

@el-gringo you can unwrap the response from the Server:
const licenseMessage = licenseServerData.getLicenseMessage(xhr.response, keySystemString, messageType);
you can extent each server, like Widevine or PlayReady.

[el-gringo]

@Achibana Thank you, but I did not find a way to access licenseServerData. It does not seem to be exported anywhere.

[dsilhavy]

license request and response modification is implemented and an example is available here:
https://reference.dashif.org/dash.js/nightly/samples/drm/license-wrapping.html