ClearKey - Error generating key request as kid is not valid base64url encoded.

[sr1990]

• Dash.js version: dev
• Browser name/version: Chrome
• OS name/version: MacOS

While trying to play clearkey content, I get the following error:

DRM: unable to create session! --Error generating key request -- TypeError

Failed to execute 'generateRequest' on 'MediaKeySession': 'kids'[0] `is not valid base64url encoded.` Value: oGpvUYhYR/i8Uq2MWlpABg

{TypeError: Failed to execute 'generateRequest' on 'MediaKeySession': 'kids'[0] is not valid base64url encoded. Value: oGpvUYhYR/i8Uq2MWlpABg

Updating the following function resolves the issue

function cencDefaultKidToBase64Representation(cencDefaultKid) {
        try {
            let kid = cencDefaultKid.replace(/-/g, '');
            kid = btoa(kid.match(/\w{2}/g).map((a) => {
                return String.fromCharCode(parseInt(a, 16));
            }).join(''));
            return kid.replace(/=/g, '')
                .replace(/\//g, '_')
                .replace(/\+/g, '-');
        } catch (e) {
            return null;
        }
    }

Function name can be updated to cencDefaultKidToBase64UrlRepresentation

Please let me know if I am missing anything here or
if this is a known issue and
if I should send a PR.
https://github.com/Dash-Industry-Forum/ClearKey-Content-Protection will also need to be updated.

Links:
https://www.w3.org/TR/encrypted-media/#using-base64url
https://www.w3.org/TR/encrypted-media/#clear-key-request-format

Thanks.

[dsilhavy]

Which stream did you use in your test?

[sr1990]

Hi @dsilhavy,
Unfortunately, I cannot share the stream right now but following are the content protection tags in the mpd:

 <ContentProtection schemeIdUri="urn:mpeg:dash:mp4protection:2011" value="cenc" cenc:default_KID="A06A6F51-8858-47F8-BC52-AD8C5A5A4006"/>
            <ContentProtection schemeIdUri="urn:uuid:e2719d58-a985-b3c9-781a-b030af78d30e" value="ClearKey1.0">
                <clearkey:Laurl Lic_type="EME-1.0">http://10.0.0.10:3000/AcquireLicense</clearkey:Laurl>
            </ContentProtection>

Please let me know if you need anything else from the mpd.
Also, I would like to point out that the stream can be played on Shaka player and Android's Exoplayer.

[dsilhavy]

Thanks, fixed in #4026

[sr1990]

Thanks @dsilhavy!