- From: <bugzilla@jessica.w3.org>
- Date: Tue, 23 Sep 2014 00:08:31 +0000
- To: public-html-media@w3.org
https://www.w3.org/Bugs/Public/show_bug.cgi?id=26887 Bug ID: 26887 Summary: Allowing license servers and CDMs to control data persistence and secure release Product: HTML WG Version: unspecified Hardware: PC OS: Windows NT Status: NEW Severity: major Priority: P2 Component: Encrypted Media Extensions Assignee: adrianba@microsoft.com Reporter: jdsmith@microsoft.com QA Contact: public-html-bugzilla@w3.org CC: mike@w3.org, public-html-media@w3.org Our current spec uses sessionType to control storage of session data, and load() and remove() to support secure release. These assume the app is in control of the secure release process, and in many respects, the CDM need not be aware. Unfortunately, these features don’t work well with implementations that have the license server and CDM control secure release using terms set in the license itself. This license server model has many positives. It can securely manage license persistence, expirations and secure release features, directly and with little app complexity. We believe supporting it will be important for EME; however, there are issues between it and the current spec: 1. At most, sessionType could only be a hint to the process in the license controlled model, as the license terms would determine whether the license itself is stored, and whether it is subject to secure release requirements. 2. Load() is problematic, since licenses under secure release may still be temporary (in fact this may be desirable) and may be released even though secure release messages are still pending. 3. Status information on secure release is maintained in the CDM and currently would be inaccessible to applications. We could make this information accessible, but the utility of any function we provide for this might vary by CDM. Some of these issues result from overloading the original intents for MediaKeySession and sessionId. These originally managed the short term exchange of messages and have grown to now manage the lifetime of media content playback on a given device. The original short term intention was a much better fit with license server controlled CDM implementations. We believe the license server controlled model must be supported by EME. I’d like to get agreement on this and discuss whether it can be done with a common EME abstraction or not. -- You are receiving this mail because: You are on the CC list for the bug.
Received on Tuesday, 23 September 2014 00:08:33 UTC