WMRMChallenge.CheckClientCapability

You can use the CheckClientCapability method to determine the features that are supported by the DRM component of a player. Use this information to choose the type of license to issue, or whether to issue a license at all. For example, if the minimum security level that you require for your content is not supported by the client, you can refuse to issue a license when requested.

Syntax

Boolean = WMRMChallenge.CheckClientCapability(bstrFeatureName)

Parameters

bstrFeatureName

[in] String containing the feature name.

Return Values

If the method succeeds, it returns a Boolean value indicating whether the client supports the specified feature. If the property fails, it returns a number in the error object.

Example Code

' Assume that the content packager has sent encrypted content and 
' a header to a consumer. The consumer's computer determines that 
' a license is needed and 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.
'
' For more information about the header, see the WMRMHeader object.


' Declare variables and objects.

    Dim sHeader, sClientInfo, sPubKey, lResult, dwActionCnt
    Dim sLicRequest, lIndex, sVerClient, sVerSecurity, sAppSecurity
    Dim sAction()
    Dim HeaderObj
    Dim ChallengeObj
    Dim bAppExcl, bMinSDK, bSAPSupport

' Create objects.

    Set HeaderObj = Server.CreateObject("Wmrmobjs.WMRMHeader")
    Set ChallengeObj = Server.CreateObject("Wmrmobjs.WMRMChallenge")
  
' 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

' 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

' Verify that the client supports application exclusion and SAP, and
' is based on Windows Media Format SDK 7.1 or later. 

  bAppExcl = ChallengeObj.CheckClientCapability("ApplicationExclusion")
  if (bAppExcl = False) then
      ' Application exclusion is not supported.
  end if

  bMinSDK = ChallengeObj.CheckClientCapability("MinimumClientSDKSecurity")
  if (bMinSDK = False) then
      ' The client is not based on Windows Media Format SDK 7.1 or later.
  end if

  bSAPSupport = ChallengeObj.CheckClientCapability("SAPMode")
  if (bSAPSupport = False) then
      ' SAP is not supported.
  end if

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

• Excluding Player Applications
• Kernel-Level Security (Secure Audio Path)
• Programming Windows Media Rights Manager in C++
• Security Levels
• WMRMChallenge Object