WMRMLicGen.Attribute
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WMRMLicGen.Attribute
The Attribute property specifies and retrieves name-value pairs in a license. This property lets you add metadata to licenses, which can be used in the future for features in a player application. For example, players could display license information to consumers.
Syntax
WMRMLicGen .Attribute( bstrName ) = String String = WMRMLicGen.Attribute(bstrName)
Parameters
bstrName
[in] String containing the attribute name. It is strongly recommended that you use the names in the following table.
| Value | Description |
| ArtistURL | Contains the URL of the artist's Web site. |
| Author | Contains the name of the content author. |
| ContentDistributor | Contains the name of the distributor of the content. |
| ContentType | Contains the type of content, such as music or video. |
| Copyright | Contains the copyright of the content. |
| Description | Contains a description of the content. |
| LGPUBKEY | License revocation public key |
| LicenseDistributor | Contains the name of the license distributor. |
| LicenseDistributorURL | Contains the URL of the license issuer's Web site. |
| Rating | Contains the rating indicating the type of audience for which the content is suitable. |
| Title | Name of the content. |
| UID | User ID |
Return Values
If the property succeeds, it returns a String containing the attribute value. If it fails, it returns a number in the error object.
| Return code | Description |
| 0x80048001 | A parameter is not valid. |
| 0x80048003 | The object cannot be initialized. |
| 0x80048010 | The attribute cannot be set. |
Remarks
Attributes do not affect the way a license is used on the client computer. Attribute names are case-sensitive, and both the name and value must be specified in a valid XML format. If you duplicate an existing attribute, the earlier attribute is updated.
Example Code
' Assume that the content packager has sent encrypted content and
' a header to a consumer. The client computer posts a challenge to
' the license issuer. The challenge contains the header sent by the
' content packager, actions requested by the client, and information
' about the client computer. To issue a license, perform the
' following steps.
'
' Declare variables and objects.
Dim sHeader, sClientInfo, sPubKey, lResult, dwActionCnt
Dim sLicRequest, lIndex, sRights, sKeyID, sSeed, sKey
Dim varCategory, varVersion, sLicense, sLicResponse
Dim sAction
Dim HeaderObj
Dim ChallengeObj
Dim Rights Obj
Dim LicGenObj
Dim ResponseObj
' Create objects.
Set HeaderObj = Server.CreateObject("Wmrmobjs.WMRMHeader")
Set ChallengeObj = Server.CreateObject("Wmrmobjs.WMRMChallenge")
Set RightsObj = Server.CreateObject("Wmrmobjs.WMRMRights")
Set LicGenObj = Server.CreateObject("Wmrmobjs.WMRMLicGen")
Set KeysObj = Server.CreateObject("Wmrmobjs.WMRMKeys")
Set ResponseObj = Server.CreateObject("Wmrmobjs.WMRMResponse")
' Retrieve the license request from the client computer.
sLicRequest = request.Form("challenge")
' Set the license request into the WMRMChallenge object.
ChallengeObj.Challenge = sLicRequest
' Retrieve the header from the challenge.
sHeader = ChallengeObj.Header
' Check for revocation information.
strRevinfo = ChallengeObj.RevInfo
ContainsRevinfo = ChallengeObj.RevInfoPresent
' Set the header into the WMRMHeader object.
HeaderObj.Header = sHeader
' Verify the header with the public key created by the content
' packager.
lResult = HeaderObj.Verify(sPubKey)
if (lResult = 0) then
' The header has been corrupted.
end if
' Retrieve the client information section of the challenge.
sClientInfo = ChallengeObj.ClientInfo
' Define the additional rights to be granted to the consumer.
RightsObj.Reset
RightsObj.AllowBackupRestore = True
RightsObj.AllowCopy = False
RightsObj.BeginDate = "#20050101Z#"
RightsObj.ExpirationDate = "#20051231Z#"
RightsObj.DisableOnClockRollback = True
' Retrieve the string containing the defined rights, and set
' the rights into the license.
sRights = RightsObj.GetAllRights()
LicGenObj.Rights = sRights
' Set the client information into the license.
LicGenObj.ClientInfo = sClientInfo
' Check the individualized version of Windows Media Rights Manager
' running on the client computer.
LicGenObj.GetClientVersion varCategory, varVersion
Select Case varCategory
Case 0
' Client is not individualized.
case 1
' Client is individualized.
Case Else
' Invalid client category.
End Select
' Call the BindToPubKey property to send the client a public
' key used to verify the license. When the license contains a
' public key, Windows Media Rights Manager on the client computer
' verifies the license. The public key is included in the certificate
' sent to the license issuer by Windows Media License Service.
LicGenObj.BindToPubKey = sPubKey
' Set the name of the licensing server into the license.
LicGenObj.Attribute("Author") = "name of the author"
LicGenObj.Attribute("ContentDistributor") = "name of the distributor"
LicGenObj.Attribute("ContentType") = "type of content distributed"
LicGenObj.Attribute("Title") = "title of the content"
' Set the priority into the license.
LicGenObj.Priority = 10
' Retrieve the key ID from the header, and set it into the license.
sKeyID = HeaderObj.KeyID
LicGenObj.KeyID = sKeyID
' Use the key ID and your stored license key seed to create the
' key, and set the key into the license. The license key seed is a
' shared secret between the content packager and the license issuer.
KeysObj.KeyID = sKeyID
KeysObj.Seed = sSeed
sKey = KeysObj.GenerateKey()
LicGenObj.SetKey("MSDRM", sKey)
' Get the certificate revocation lists that are supported by the client.
strClientCRLs = LicGenObj.SupportedCRLS
' Create a license.
sLicense = LicGen.GetLicenseToDeliver()
' Add this license to the license response.
Call ResponseObj.AddLicense("2.0.0.0", sLicense)
Call ResponseObj.AddRevocationData(strRevinfo, strClientCRLs, ContainsRevinfo)
' Retrieve a string containing the license response.
sLicResponse = Response.GetLicenseResponse()
Requirements
Version: Windows Media Rights Manager 7 SDK or later
Reference: wmrmobjs 1.0 Type Library
Library: wmrmobjs.dll
Platform: Windows Server 2003
See Also
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