pywidevine/CHANGELOG.md

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

1.2.0 - 2022-07-30

Added

• The CLI command migrate can now accept a folder path to batch migrate WVD files.
• The Cdm now uses custom exceptions where the use case is justified. All custom exceptions are under a parent custom exception to allow catching of any Pywidevine exception.

Changed

• The Cdm has been reworked as a session-based Cdm. You now initialize the Cdm with just the device you wish to use, and now you open sessions with Cdm.open() to get a session ID. For usage example see license CLI command in main.py.
• For the above change, serve CLI command interface has changed and now uses a /open/{device} endpoint to start a Cdm session. The client will need to first use /open to get a Session ID, then pass the Session ID through to both /challenge and /keys now.
• The Cdm no longer requires you to specify raw bool parameter. It now supports arbitrary and valid Widevine Cenc Header Data without needing to explicitly specify which it is.
• The Cdm pssh param has been renamed as init_data. Doc-strings have been changed to prioritize explanation of it referring to Widevine Cenc Header rather than PSSH Boxes. This is to show that the Cdm more-so wants Init Data than a PSSH box. The full PSSH is never kept nor ever used, only it's init data is. It still supports PSSH box data.
• Cdm set_service_certificate() now returns the provider ID string rather than the underlying (and now verified) DrmCertificate. This is because the DrmCertificate is not likely useful and would still be possible to obtain in full but quick access to the Provider ID may be more useful.
• License responses can now be only be parsed once by Cdm.parse_license(). Any further attempts will raise an InvalidContext exception. This is because context data is now cleared for it's respective License Request once it's parsed to reduce data lingering in memory.
• Trove Classifier for Development Status is now 5 (Production/Stable).

Removed

• You can no longer provide a direct DrmCertificate to Cdm.set_service_certificate() for security reasons. You must provide either a SignedDrmCertificate or a SignedMessage containing a SignedDrmCertificate.
• PSSH from_init_data() has been removed. It was unused and is unnecessary with improvements to get_as_box().

Fixed

• Cdm set_service_certificate() now verifies the signature of the provided Certificate. This patches a trivial exploit/workaround that allows an attacker to recover the plaintext Client ID from an encrypted Client ID.
• Cdm parse_license() now verifies the input message type as a LICENSE message.
• Cdm parse_license() now clears context for the License Request once it's License Response message has been parsed. This reduces data lingering in the context dictionary when it may only be needed once.
• The Context Availability error handler in Cdm parse_license() has been fixed.
• Typing of type_ param of Cdm.get_license_challenge() has been fixed.

1.1.1 - 2022-07-22

Fixed

• The --vmp argument of the create-device command is now optional.

1.1.0 - 2022-07-21

Added

• Added support for setting a Service Certificate in SignedDrmCertificate form as well as raw DrmCertificate form. However, It's unlikely for the service to provide the certificate in raw DrmCertificate form without a signature.
• Added a CLI command create-device to create Widevine Device (.wvd) files from RSA PEM/DER Private Keys and Client ID blobs. You can also provide VMP (FileHashes) data which will be merged into the Client ID blob.
• Added a CLI command migrate that uses Device.migrate() and dump() to migrate older v1 Widevine Device files to v2.
• Added the v1 Structure of Widevine Devices for migration use.
• Added Device.migrate() class method that effectively loads older format WVD data. You can then use dumps() to get back the WVD data in the latest supported format.
• Added ability to use Privacy mode on the test command.

Changed

• Set Service Certificates are now stored as the raw underlying DrmCertificate as the signature data is unused by the CDM.
• Moved all Widevine Device structures under a Structures class.
• I removed the send_key_control_nonce flag from all Structures even though it was technically used. This is because the flag was never used as of this project, and I do not want to take up the flag slot.

Fixed

• Devices dump() function now uses the correct type_ parameter when building the struct.
• Fixed release date year of v1.0.0 and v1.0.1 in the changelog.

1.0.1 - 2022-07-21

Added

• More information to the PyPI meta information, e.g., classifiers, readme, some URLs.

Changed

• Moved the License Type parameter from the Cdm constructor to get_license_challenge().
• The Session ID is no longer used as the Request ID which could help with blocks or replay checks due to it being the same Session ID for each request. It's now a random 16 byte value each time.
• Only the Context Data of each license request is now stored instead of the full message.

Removed

• Removed unnecessary and unused raw Cdm class instance variable.

Fixed

• CDMs set_service_certificate() now correctly raises a DecodeError on Decode Error instead of a ValueError.
• Context Data will now always match to their corresponding License Responses. This fixes an issue where creating a second challenge would overwrite the context data of the first challenge. Parsing the first challenge after would result in either a key decrypt error, or garbage key data.

1.0.0 - 2022-07-20

Initial Release.