Rights Management Services
From Wikipedia, the free encyclopedia
Windows Rights Management Services (also called Rights Management Services or RMS) is a Microsoft Windows technology that is a form of digital rights management used for protecting documents such as corporate e-mail, Word documents, and web pages. Companies can use this technology to encrypt information stored in such document formats, and through server-based policies, prevent the protected content from being decrypted except by specified people or groups, in certain environments, under certain conditions, and for certain periods of time. Specific operations like printing, copying, editing, forwarding, and deleting can be allowed or disallowed by content authors for individual pieces of content, and RMS administrators can deploy RMS templates that group these rights together into predefined rights that can be applied en masse.
The RM server debuted in Windows Server 2003, with client API libraries made available for Windows XP and Windows 2000 as well. Windows Vista and Windows Server 2008 also supports Rights Management Services. In Windows Server 2008, Windows Rights Management Services has been renamed to Active Directory Rights Management Services, reflecting a higher level of integration with Active Directory.
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[edit] Overview
Windows Rights Management Services is used for restricting access to rights-protected content to authorized users only. It uses a client-server architecture, using Windows Server 2003 and/or Windows Server 2008 to host the Active Directory Rights Management Server that issues RMS licenses. The RMS client is required for both creating rights-protected content as well as accessing it. Applications that either create or provide access to protected content must be RMS-aware and have to implement the RMS client APIs explicitly. However, add-ons can be used to make an application RMS-enabled even if it does not natively implement RMS functionality.
RMS-protected documents can be created by RMS-enabled applications. RMS-protected content is encrypted and contains an embedded Usage Policy, which defines the rights each user or group has to the content. The RMS system works by assigning rights to trusted entities, which are either single users or groups of users. Rights are assigned on a per-entity basis. RMS defines and recognizes several rights by default - such as permission to read, copy, print, save, forward, and edit - and can be extended to recognize additional rights (which each application would have to explicitly implement). In Windows Server 2008 RMS rights can also be assigned to users who have federated trust via Windows Active Directory Federation Services.
When restricting rights to a document, a trusted entity encrypts a random AES key with an RSA public key that can be validated with the certificate in the XrML identity license that is issued to an RMS server (note: this XrML license is not an X.509v3 digital certificate). The AES key is used to encrypt the document. When accessing a protected document (using an RMS-enabled application) the RMS client runtime authenticates the recipient to the RM server, using the recipient's XrML identity license. The RM server then issues a use license that can be used by the RMS client runtime to decrypt the document. The RMS client uses this use license to provide access to the application, which enforces the document restrictions for that user.
One significant feature of the RMS system is that any document can optionally include an HTML rendering of the document so that the document can be viewed even when the intended application is not available. This is enabled using a compound document format. Both versions of the document are subject to the same usage policies, and an RMS-enabled HTML viewer is required to view this alternative form of the document content. For example, Microsoft Office 2003 Professional or greater is able to optionally include an HTML version of the document content. The Rights Management Add-on for Internet Explorer allows users who do not have Microsoft Office 2003 or later installed to view these RM-protected files.
[edit] RMS-enabled Microsoft applications
Windows RMS is supported (implemented) by the following Microsoft products:
- Microsoft Office System 2003 - Word, Excel, PowerPoint, Outlook
- Microsoft Office 2007 - Word, Excel, PowerPoint, Outlook, InfoPath
- Microsoft Office SharePoint Server 2007
- Exchange Server 2007
- XPS (XML Paper Specification) v1.0
- Internet Explorer (through use of the RM Add-on for IE)
