Issuing a License in a License Chain
.gif)
| Previous | Next |
Issuing a License in a License Chain
When issuing licenses for a license chain, the issuer might need to issue an entire license chain or only elements of the chain. So, the license issuer needs to know which license elements to issue.
The content header contains the uplink ID (the root key ID) in the license chain, which is also included in the license request. Use the WMRMChallenge.Uplinks property to retrieve this information from the license request. A WMRMUplinkCollection ** object is returned, and it contains a collection that corresponds to the elements in the license chain (item 0 is the leaf license, item 1 is the root license.) You can iterate through the collection and retrieve information into a WMRMUplink object, which provides the key ID and license state data for each license element. The license state data in the WMRMLicenseStateData object provides information about the licenses that are already present on the client computer, such as expiration dates and remaining play counts. Using this information, the license issuer can determine which elements in the license chain need to be reissued. For example, if the root license has expired but the leaf license is still valid, only a root license needs to be reissued.
When you issue a license from a license chain, you issue it almost as you would a simple license. The root license is bound to the computer, but the leaf license is bound to the root license by specifying the root key and key ID in the leaf license by using the WMRMLicGen.UplinkKey and WMRMLicGen.UplinkKid properties.
Additionally, rather than the 7-byte key used for simple or leaf licenses, the root licenses in a chain require a key of 8 bytes, which must be created using the WMRMKeys.GenerateKeyEx method.
Example Code
The following example is based on the sample page Simple.asp in the C:\WMSDK\WMRM10.1\samples folder, but this sample can issue a simple or a chained license depending on the license request.
<%@ LANGUAGE="VBScript"%>
<%
Response.Buffer = True
Response.Expires = 0
Do
On Error Resume Next
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
' Declare variables.
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
Dim ChallengeObj ' WMRMChallenge object
Dim ChainCollObj ' WMRMUplinkCollection object
Dim ChainObj ' WMRMUplink object
Dim LeafLicenseStateObj ' WMRMLicenseStateData object
Dim RootLicenseStateObj ' WMRMLicenseStateData object
Dim HeaderObj ' WMRMHeader object
Dim KeyObj ' WMRMKeys object
Dim RightsObj ' WMRMRights object
Dim LicenseObj ' WMRMLicGen object
Dim ResponseObj ' WMRMResponse object
Dim RestrictObj ' WMRMRestrictions object
Dim ContentServerPubKey ' Public key of the content server
Dim Seed ' License key seed
Dim Delivery ' Delivery flag
Dim LicChain ' License chain flag
Dim Silent ' Silent delivery flag
Dim strLicenseRequested ' License request string
Dim varClientInfo ' Client information
Dim varHeader ' Content header
Dim blnResult ' Signature verification
Dim SimpleLeafKID ' Key ID of a simple license or leaf license
Dim IndiVersion ' Security version of the DRM component
Dim strRevinfo ' Revocation information string
Dim ContainsRevinfo ' Flag for revocation information
Dim strClientCRLs ' Supported revocation lists string
Dim RootKID ' Key ID of the root license
Dim RootCat ' License state data for root licenses
Dim RCountArray ' Count array
Dim RDateArray ' Date array
Dim RStreamID ' Stream ID
Dim RVague ' Vagueness
Dim IssueRoot ' Root license flag
Dim Rcounts ' Remaining counts
Dim RstartDate ' Start date
Dim RExpDate ' Expiration date
Dim LeafCat ' License state data for leaf licenses
Dim LCountArray ' Count array
Dim LDateArray ' Date array
Dim LStreamID ' Stream ID
Dim LVague ' Vagueness
Dim IssueLeaf ' Leaf license flag
Dim Lcounts ' Remaining counts
Dim LstartDate ' Start date
Dim LExpDate ' Expiration date
Dim SimpleLeafKey ' Key for the simple license or leaf license
Dim SimpleLeafRights ' Rights string for the simple license or leaf license
Dim SimpleLeafLicense ' License for the simple license or leaf license
Dim RootKey ' Key for the root license
Dim RootRights ' Rights string for the root license
Dim RootLicense ' Root license
Dim LicResponse ' License response
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
' Set variables.
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
ContentServerPubKey = Application("contentserverpubkey")
Seed = Application("seed")
Delivery = ""
LicChain = ""
Silent = True
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
' Check the request for silent or non-silent delivery.
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
If (Request.Form("nonsilent") <> "") Then Silent = False
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
' Retrieve the license request. Get the client information and content header.
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
Set ChallengeObj = Server.CreateObject("WMRMObjs.WMRMchallenge")
strLicenseRequested = Request.Form("challenge")
ChallengeObj.Challenge = strLicenseRequested
varClientInfo = ChallengeObj.ClientInfo
varHeader = ChallengeObj.Header
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
' Check for revocation information.
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
strRevinfo = ChallengeObj.RevInfo
ContainsRevinfo = ChallengeObj.RevInfoPresent
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
' Put the content header into the header object. Retrieve
' the KID and required individualization version.
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
Set HeaderObj = Server.CreateObject("WMRMObjs.WMRMheader")
HeaderObj.Header = varHeader
blnResult = HeaderObj.Verify(ContentServerPubKey)
SimpleLeafKID = HeaderObj.KeyID
IndiVersion = HeaderObj.IndividualizedVersion
' If IndividualizedVersion is not specified, an error
' might be set.
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
' If this is a chained license, retrieve the root license KID.
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
Set ChainCollObj = ChallengeObj.Uplinks
If (Err.Number = 0) Then ' Request for a license chain.
LicChain = "chain"
' Get license state data and key ID for the root license.
Set ChainObj = ChainCollObj.item(1)
RootKID = ChainObj.KID
' Get license state data to determine whether to issue
' a root license.
Set RootLicenseStateObj = ChainObj.LicenseState
RootCat = cstr(RootLicenseStateObj.Category)
Select Case RootCat
case 0 ' The root license has no rights.
IssueRoot = True
case 1 ' The root license has unlimited play counts.
IssueRoot = False
case 2 ' The root license has remaining play counts.
RCountArray = RootLicenseStateObj.Counts
RCounts = cstr(RCountArray(0))
IssueRoot = False
case 3 ' The root license has a start date.
RDateArray = RootLicenseStateObj.Dates
RStartDate = cstr(RDateArray(0))
IssueRoot = False
case 4 ' The root license has an expiration date.
RDateArray = RootLicenseStateObj.Dates
RExpDate = cstr(RDateArray(0))
IssueRoot = False
case 5 ' The root license has start and expiration dates.
RDateArray = RootLicenseStateObj.Dates
RStartDate = cstr(RDateArray(0))
RExpDate = cstr(RDateArray(1))
IssueRoot = False
case 6 ' The root license has a start date and
' remaining play counts.
RDateArray = RootLicenseStateObj.Dates
RStartDate = cstr(RDateArray(0))
RCountArray = RootLicenseStateObj.Counts
RCounts = cstr(RCountArray(0))
IssueRoot = False
case 7 ' The root license has an expiration date and
' remaining play counts.
RDateArray = RootLicenseStateObj.Dates
RExpDate = cstr(RDateArray(0))
RCountArray = RootLicenseStateObj.Counts
RCounts = cstr(RCountArray(0))
IssueRoot = False
case 8 ' The root license has start and expiration
' dates, and remaining play counts.
RDateArray = RootLicenseStateObj.Dates
RStartDate = cstr(RDateArray(0))
RExpDate = cstr(RDateArray(1))
RCountArray = RootLicenseStateObj.Counts
RCounts = cstr(RCountArray(0))
IssueRoot = False
case 9 ' The root license expires after first use.
IssueRoot = False
End Select
RStreamID = RootLicenseStateObj.StreamID ' This value is always 0.
RVague = RootLicenseStateObj.Vagueness
' Get license state data to determine whether to issue
' a leaf license.
Set ChainObj = ChainCollObj.item(0)
Set LeafLicenseStateObj = ChainObj.LicenseState
LeafCat = cstr(LeafLicenseStateObj.Category)
Select Case LeafCat
case 0 ' The leaf license has no rights.
IssueLeaf = True
case 1 ' The leaf license has unlimited play counts.
IssueLeaf = False
case 2 ' The leaf license has remaining play counts.
LCountArray = LeafLicenseStateObj.Counts
LCounts = cstr(LCountArray(0))
IssueLeaf = False
case 3 ' The leaf license has a start date.
LDateArray = LeafLicenseStateObj.Dates
LStartDate = cstr(LDateArray(0))
IssueLeaf = False
case 4 ' The leaf license has an expiration date.
LDateArray = LeafLicenseStateObj.Dates
LExpDate = cstr(LDateArray(0))
IssueLeaf = False
case 5 ' The leaf license has start and expiration dates.
LDateArray = LeafLicenseStateObj.Dates
LStartDate = cstr(LDateArray(0))
LExpDate = cstr(LDateArray(1))
IssueLeaf = False
case 6 ' The leaf license has a start date and
' remaining play counts.
LDateArray = LeafLicenseStateObj.Dates
LStartDate = cstr(LDateArray(0))
LCountArray = LeafLicenseStateObj.Counts
LCounts = cstr(LCountArray(0))
IssueLeaf = False
case 7 ' The leaf license has an expiration date and
' remaining play counts.
LDateArray = LeafLicenseStateObj.Dates
LExpDate = cstr(LDateArray(0))
LCountArray = LeafLicenseStateObj.Counts
LCounts = cstr(LCountArray(0))
IssueLeaf = False
case 8 ' The leaf license has start and expiration
' dates, and remaining play counts.
LDateArray = LeafLicenseStateObj.Dates
LStartDate = cstr(LDateArray(0))
LExpDate = cstr(LDateArray(1))
LCountArray = LeafLicenseStateObj.Counts
LCounts = cstr(LCountArray(0))
IssueLeaf = False
case 9 ' The root license expires after first use.
IssueLeaf = False
End Select
LStreamID = LeafLicenseStateObj.StreamID ' This value is always 0.
LVague = LeafLicenseStateObj.Vagueness
Else ' An error indicates a request for a simple license.
err.clear
LicChain = "simple"
End If
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
' Generate the keys.
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
Set KeyObj = Server.CreateObject("WMRMObjs.WMRMkeys")
KeyObj.KeyID = SimpleLeafKID
KeyObj.Seed = Seed
' This is a key for either a simple license or a leaf license.
SimpleLeafKey = KeyObj.GenerateKey()
If (LicChain = "chain") Then ' Generate the 8-byte key for the root license.
KeyObj.KeyID = RootKID
RootKey = KeyObj.GenerateKeyEx(8)
End If
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
' Get the certificate revocation lists that are supported by the client.
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
strClientCRLs = LicGenObj.SupportedCRLS
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
' Set the rights.
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
Set RightsObj = Server.CreateObject("WMRMObjs.WMRMRights")
If (LicChain = "simple") Then ' Generate rights for a simple license.
RightsObj.Playcount = 2
RightsObj.AllowCopy = True
RightsObj.CopyCount = 5
RightsObj.AllowCollaborativePlay = False
RightsObj.AllowBackupRestore = False
RightsObj.AllowPlaylistBurn = True
RightsObj.MaxPlaylistBurnCount = 5
RightsObj.PlaylistBurnTrackCount = 15
RightsObj.MinimumClientSDKSecurity = 3000
RightsObj.MinimumSecurityLevel = 1000
RightsObj.GracePeriod = 24
RightsObj.ExpirationDate = "#20051231Z#"
RightsObj.DeleteOnClockRollback = False
RightsObj.DisableOnClockRollback = True
' Set copy restrictions.
Set RestrictObj = Server.CreateObject("WMRMObjs.WMRMRestrictions")
Call RestrictObj.AddRestriction(6, 400)
RightsObj.CopyRestrictions = RestrictObj.GetRestrictions
If Err.Number = 0 Then
SimpleLeafRights = RightsObj.GetAllRights
End If
Else
' Generate rights for a leaf license.
RightsObj.AllowCopy = True
RightsObj.CopyCount = 5
RightsObj.AllowCollaborativePlay = False
RightsObj.AllowBackupRestore = False
RightsObj.AllowPlaylistBurn = True
RightsObj.MaxPlaylistBurnCount = 5
RightsObj.PlaylistBurnTrackCount = 15
RightsObj.GracePeriod = 24
RightsObj.MinimumClientSDKSecurity = 3000
RightsObj.MinimumSecurityLevel = 1000
' Set copy restrictions.
Set RestrictObj = Server.CreateObject("WMRMObjs.WMRMRestrictions")
Call RestrictObj.AddRestriction(6, 400)
RightsObj.CopyRestrictions = RestrictObj.GetRestrictions
' Get the rights string.
If Err.Number = 0 Then
SimpleLeafRights = RightsObj.GetAllRights
End If
' Generate rights for a root license.
RightsObj.Reset
RightsObj.Playcount = 1
RightsObj.AllowCopy = True
RightsObj.AllowPlaylistBurn = True
RightsObj.AllowCollaborativePlay = False
RightsObj.AllowBackupRestore = False
RightsObj.ExpirationDate = "#20051231Z#"
RightsObj.DeleteOnClockRollback = False
RightsObj.DisableOnClockRollback = True
' Set copy restrictions.
RightsObj.CopyRestrictions = RestrictObj.GetRestrictions
' Get the rights string.
If Err.Number = 0 Then
RootRights = RightsObj.GetAllRights
End If
End If
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
' Generate a simple license or leaf license.
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
Set LicenseObj = Server.CreateObject("WMRMObjs.WMRMlicgen")
LicenseObj.KeyID = SimpleLeafKID
LicenseObj.SetKey "", SimpleLeafKey
LicenseObj.Priority = 10
LicenseObj.Rights = SimpleLeafRights
LicenseObj.ClientInfo = varClientInfo
LicenseObj.BindToPubKey = ContentServerPubKey
LicenseObj.Attribute("ContentDistributor") = "Distributor Name"
LicenseObj.IndividualizedVersion = IndiVersion
If (LicChain = "chain") Then ' Link to the root license.
LicenseObj.UplinkKid = RootKID
LicenseObj.UplinkKey = RootKey
End If
SimpleLeafLicense = LicenseObj.GetLicenseToDeliver()
Delivery = "deliver"
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
'Generate a root license.
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
If (LicChain = "chain") Then
Set LicenseObj = Nothing
Set LicenseObj = Server.CreateObject("WMRMObjs.WMRMlicgen")
LicenseObj.KeyID = RootKID
LicenseObj.SetKey "", RootKey
LicenseObj.Priority = 10
LicenseObj.Rights = RootRights
LicenseObj.ClientInfo = varClientInfo
LicenseObj.BindToPubKey = ContentServerPubKey
LicenseObj.Attribute("ContentDistributor") = "Distributor Name"
LicenseObj.IndividualizedVersion = IndiVersion
RootLicense = LicenseObj.GetLicenseToDeliver()
End If
Loop While False
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
' Send an error message or deliver the license.
'"""""""""""""""""""""""""""""""""""""""""""""""""""""
If (Delivery = "" and Err.Number <> 0) Then
Response.Write "0x" + cstr(hex(err.number)) + " :" & Err.Description
ElseIf (Delivery = "deliver") Then
Set ResponseObj = Server.CreateObject("WMRMObjs.WMRMresponse")
If (LicChain = "simple") or (IssueLeaf = True) Then
' Include a simple license or leaf license in the license response.
Call ResponseObj.AddLicense("2.0.0.0", SimpleLeafLicense)
End If
If (IssueRoot = True) Then
' Include the root license in the license response.
Call ResponseObj.AddLicense("2.0.0.0", RootLicense)
End If
Call ResponseObj.AddRevocationData(strRevinfo, strClientCRLs, ContainsRevinfo)
If (Silent = True) Then
LicResponse = ResponseObj.GetLicenseResponse()
Response.Write LicResponse
ElseIf (Silent = False) Then
' This replaces quotes to pass a value.
' ResponseObj.ReplaceQuotesWith = """""" ' For VBScript.
ResponseObj.ReplaceQuotesWith = "\""" ' For JavaScript.
LicResponse = ResponseObj.GetLicenseResponse()
%>
<!-- #include file="simple_ns.asp" -->
<%
End If
End If
' Clear objects.
Set ChallengeObj = Nothing
Set ChainCollObj = Nothing
Set ChainObj = Nothing
Set LicenseStateObj = Nothing
Set HeaderObj = Nothing
Set KeyObj = Nothing
Set RightsObj = Nothing
Set LicenseObj = Nothing
Set ResponseObj = Nothing
%>
See Also
- Generating and Issuing Licenses
- How License Chaining Works
- Specifying a License Chain When Protecting Content
- WMRMHeader Object
- WMRMLicenseStateData
| Previous | Next |