The ODK Library is used to generate and parse core OEMCrypto messages. This library is used by both OEMcrypto on a device, and by Widvine license and provisioning servers. The source of truth for these files is in the server code base on piper. Do not edit these files in the Android directory tree or in the Widevine Git repository. If you need to edit these files and are not sure how to procede, please ask for help from an engineer on the Widevine server or device teams.