WMRMHeader Object
The WMRMHeader object manipulates content headers. If you are packaging multimedia content into a Windows Media file, you must use this object to create a content header. A content header consists of the following information:
- The key ID used to create a key.
- A content ID to uniquely identify the encrypted content.
- Attributes that identify the content.
- A URL identifying the Internet address of the license issuer.
- The minimum application security version number required to play the Windows Media file.
The content header contains only the key ID, not the key. To re-create the key and package it in a license, a license issuer needs both the key ID and the shared license key seed.
The content ID is optional but highly recommended. For example, assume that you have multiple pieces of content and that, for a specific content, you want to delineate different rights for different consumer groups. You can do this by associating each group of rights with a different key ID, all of which are associated with a single content ID.
Attributes are name-value pairs that can be used to identify the content. For example, attributes can identify the name of the content packager, the name of the artist, and so on.
The WMRMHeader object exposes the following properties and methods.
Property | Description |
Attribute | Specifies and retrieves name-value pairs. |
ContentID | Specifies and retrieves the ID of the encrypted content. |
Header | Specifies and retrieves the content header. |
IndividualizedVersion | Specifies and retrieves the minimum version of the Windows Media Rights Manager dynamic link library (DLL) that is individualized for a specific computer. |
KeyID | Specifies and retrieves the ID of the encryption key. |
LicenseAcqURL | Specifies and retrieves the URL of the Web page that the client must use to apply for a license. |
Version | Retrieves the version number from the content header. |
Method | Description |
AddUplink | Adds a key ID to the content header, indicating the root element in the content's license chain. |
RemoveUplink | Removes a key ID for a root license chain element from the content header. |
SetCheckSum | Specifies the checksum used for key verification. |
Sign | Adds a signature to the content header. |
Verify | Verifies the signature in the data section of the content header. |
See Also