Windows Media DRM
Windows Media DRM or WMDRM, is a
WMDRM includes the following components:
- Windows Media Rights Manager (WMRM) SDK for packaging content and issuing licenses
- Windows Media Format SDK (WMF SDK) for building Windows applications which support DRM and the Windows Media format
- Windows Media DRM for Portable Devices (WMDRM-PD) for supporting offline playback on portable devices (Janus)
- Windows Media DRM for Network Devices(WMDRM-ND) for streaming protected content to devices attached to a home network (Cardea)
Windows Media DRM was replaced in Windows 10 Anniversary Update in favor of Microsoft PlayReady.[1]
How it works
In May 2007 Microsoft published the network protocol behind its license acquisition mechanism.
As an anti-spoofing measure, additional fields such as playback rights and a random number are encrypted with three more predefined ECC key pairs either by the client or server software:
- client software ECC key pair KC,
- client machine ECC key pair KM,
- server software ECC key pair KS.
An analysis of version 2 of the DRM scheme in Windows Media Audio revealed that it was using a combination of
Windows Media DRM is designed to be renewable, that is, it is designed on the assumption that it will be cracked and must be constantly updated by Microsoft.[3] The result is that while the scheme has been cracked several times, it has usually not remained cracked for long.
Version 1 was released in April 1999 and supported basic business rules such as expiration dates. Version 2 was released in January 2003 and is also known as version 7.x and 9, to keep in sync with the equivalent versions of Windows Media Player. Version 3, better known as DRM v10, was released in 2004. Earlier versions of the system have cracks available, meaning content restricted with these versions can have the protections stripped. Version 10 was cracked in early 2005, but a software update was shortly pushed which sealed the relevant hole.
Generally, these sorts of cracks have all worked in the same way to a certain extent. Rather than break the encryption itself, which is infeasible, they hook or interfere with the "black box" component as it runs to dump out the content keys or the unencrypted content from memory.
Interoperability
Content delivered with WMDRM encryption is not universally accessible.
The open network protocol for digital rights management, [MS-DRM] from the MCPP collection, stipulates that software developers have a right to implement the protocol outside the Microsoft's development tools and environment.
Removal
Tools have been created to strip files of Windows Media DRM, enabling them to be played on non-Janus platforms. These tools typically were developed with one specific Individualized Blackbox Component (IBX) version in mind and rarely work on a version they were not explicitly designed for. Microsoft in addition to upgrading the IBX whenever it was cracked, also pursued legal action against those who developed and hosted these tools, driving the development and distribution even further underground and fragmenting it. These tools can be split into three categories: decrypter, key-finder, and all-in-one (finds the keys and then decrypts). Microsoft has been more successful in squashing the development and distribution of the tools capable of key finding than those that decrypt encoding, as is apparent by the continual existence of the SourceForge project FreeMe2.[4]
FairUse4WM
It was claimed that one particular tool, FairUse4WM (released on August 19, 2006)[5] written by Viodentia, had the ability to strip DRM from files protected with WMDRM.[6] This is an all-in-one tool.
Microsoft responded in several ways. First, on August 28, 2006 Microsoft released a new version of the IBX to prevent this particular tool from working. Microsoft also informed partners that they were working to further resolve this issue, given that allegedly the fix was also circumvented within days.[7] Microsoft also issued takedown notices to Web site owners distributing FairUse4WM.[8] Finally, on September 22, 2006, Microsoft filed a federal lawsuit against John Does 1–10 a/k/a "viodentia", hoping to identify the person or persons responsible.[9] However, the operator of the highest-ranked mirror of the utility, James Holden,[10] denies having received any such notices or threats. Unable to find the identity of Viodentia, in April 2007 Microsoft dropped the civil suits they had filed.[11]
By October 16, 2006, distributors using the Windows Media DRM protection, such as
DRMDBG
DRMDBG is a key-finder, it extracts the keys by hooking an instance of Windows Media Player that it launches. There are several version available each targeting a specific version. The version released on March 3, 2009 supports IBX versions 11.0.6000.6324 and 11.0.6001.8000.[13]
Mirakagi
Mirakagi was one of the first key-finders; it is no longer in development.
References
- ^ "Windows 10 Anniversary Update: Loss of music and video". Microsoft Support. Microsoft. Retrieved August 20, 2016.
- ^ [MS-DRM]: Digital Rights Management License Acquisition Data Structure, Microsoft Development Network Library, rev. 2.0, March 14, 2008.
- ^ Microsoft to Update Windows Media DRM, PC World, Aug 29, 2006 http://www.pcworld.com/article/126955/microsoft_to_update_windows_media_drm.html
- ^ "FreeMe2". April 23, 2013.
- ^ Hachman, Mark (August 26, 2006). "Microsoft To Issue Fix For DRM Stripper App". PC Magazine Online. Ziff Davis Publishing Holdings Inc. Archived from the original on June 19, 2010.
- ^ "Engadget FairUse4WM strips Windows Media DRM!". August 25, 2006. Retrieved August 25, 2006.
- ^ "Sky movies paused by DRM security flaw". The Register. Retrieved September 13, 2006.
- ^ "Microsoft tells Web site owners to take down FairUse4WM". Retrieved September 17, 2006.
- ^ "Microsoft sues Viodentia for copyright infringement". Retrieved September 26, 2006.
- ^ "Microsoft Didn't Issue Takedown Notices For FairUse4WM". Archived from the original on May 18, 2007.
- ^ "Microsoft drops case against FairUse4WM creator Viodentia". April 6, 2007. Retrieved April 23, 2007.
- ^ "今的太鼓事情" (in Japanese). October 22, 2009. Archived from the original on January 22, 2011. Retrieved October 24, 2010.
- ^ "Download the latest version of drmdbg.exe". Archived from the original on December 24, 2007. Retrieved July 27, 2009.