Group Policy Editing – Findings
by dwarfsoft on Jun.15, 2010, under Novell, Scripting, Tweet
I had started another post on Group Policy editing, and how the Policy files are structured, and how to use and improve on the existing Group Policy Editor tool. The post has been found to be far too epic, so I have decided to cover a smaller subset of recent finds.
As everybody is probably already aware, we use Novell ConsoleOne and Zenworks where I work. ConsoleOne has some interesting features that require that whenever a Group Policy is being edited it takes over as the policy on the machine that is editing it. Rather than have a useful tool like Microsofts Group Policy Management Console, Novell likes to replace the local Group Policy and then just run gpedit.msc. Which is where my first gripe about gpedit.msc comes in:
GPEdit.msc requires line by line entry of things like, for example, port exceptions and program exceptions for the Windows Firewall. This is usually not an issue except that, as I have discussed in previous posts, we have been moving towards a Windows Domain environment. Firewall Exception rules are configured within two places in Group Policy: Domain Profile and Standard Profile. I have found that there is a need to move our current Standard Profile settings across to the Domain Profile settings. After a bit of registry searching I found a neat trick for doing exactly that.
In Novell, when a GPO is opened in gpedit.msc the Group Policy Contents are loaded into the normal registry locations (as per a normal GPO being applied to user and machine) and the contents are also loaded under a specific pair of registry keys. The HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Group Policy Objects Key is created on loading gpedit.msc, and underneath a pair of Keys are created like {449E44B0-A4DC-4665-AE8F-68710E1BC1EC}Machine and {449E44B0-A4DC-4665-AE8F-68710E1BC1EC}User, where the GUID is randomly generated (or at least seems to be random) each time gpedit.msc is run. Under these keys are the branch on which the Group Policy Settings are configured.
So therefore in order to duplicate StandardProfile Settings I need to duplicate all keys and values underneath HKCU\Software\Microsoft\Windows\CurrentVersion\Group Policy Objects\{GUID}Machine\Software\Policies\Microsoft\WindowsFirewall\StandardProfile\, where {GUID} is the randomly generated GUID for editing a Group Policy Object. So far from my research I have never seen more than one GUID appear underneath the Group Policy Objects key, though your mileage may vary. So the first step is to get the User and Machine keys from under the Group Policy Objects key.
Const HKEY_CURRENT_USER = &H80000001 Const HKEY_LOCAL_MACHINE = &H80000002 Const REG_SZ = 1 Const REG_EXPAND_SZ = 2 Const REG_BINARY = 3 Const REG_DWORD = 4 Const REG_MULTI_SZ = 7 strComputer = "." Set objReg=GetObject("winmgmts:{impersonationLevel=impersonate}!\\" & _ strComputer & "\root\default:StdRegProv") strKeyPath = "Software\Microsoft\Windows\CurrentVersion\Group Policy Objects\" strStandardPath = "\Software\Policies\Microsoft\WindowsFirewall\StandardProfile\" strDomainPath = "\Software\Policies\Microsoft\WindowsFirewall\DomainProfile\" If keyExists(HKEY_CURRENT_USER,strKeyPath) Then subkeys = GetSubkeys(HKEY_CURRENT_USER,strKeyPath) If Not IsEmpty(subkeys) Then GPOMachine = subkeys(LBound(subkeys)) GPOUser = subkeys(UBound(subkeys)) RegCopyTree HKEY_CURRENT_USER, strKeyPath & GPOMachine & strStandardPath, strKeyPath & GPOMachine & strDomainPath, False Else WScript.Echo "Policy not found, please try editing the policy manually" End If Else WScript.Echo "Please start editing the Group Policy before running this script" End If
The code here is the shell of the script. We need to flesh out the functions keyExists, GetSubkeys, RegCopyTree, and valueExists (which we can’t see just yet). So first we will have a look at keyExists:
Function keyExists(Hive, Key) On Error Resume Next Err.Clear ret = objReg.EnumValues(Hive,Key,arrValues,arrValueTypes) If ret <> 0 Then keyExists = False Else keyExists = True End If Err.Clear On Error Goto 0 End Function
Fairly straightforward, we try and enumerate the values of a key. If we succeed then the key does exist, otherwise it doesn’t. We will use the same principle for checking if a Value Exists.
Function valueExists(Hive, Key, ValueName) On Error Resume Next Err.Clear valueExists = False If Not keyExists(Hive, Key) Then Exit Function End If ret = objReg.EnumValues(Hive,Key,arrValues,arrValueTypes) If IsNull(arrValues) Then Exit Function End IF For i = LBound(arrValues) to UBound(arrValues) If LCase(CStr(arrValues(i))) = LCase(CStr(ValueName)) Then valueExists = True Exit Function End If Next valueExists = False Err.Clear On Error Goto 0 End Function
Here, we take the Enumeration of the Keys Values a step further and actually step through them looking for a match with ValueName. I have opted for a Case Insensitive search due to registry being case insensitive with value names.
Function GetSubkeys(Hive, Key) On Error Resume Next Err.Clear ret = objReg.EnumKey(Hive,Key,arrSubkeys) GetSubkeys = arrSubkeys Err.Clear On Error Goto 0 End Function
Possibly the simplest of the functions, GetSubkeys just returns an array of Keys underneath the current Key. The most indepth function we require is the RegCopyTree:
Function RegCopyTree(Hive, SrcKey, DestKey, Force) On Error Resume Next Err.Clear strComputer = "." Set StdOut = WScript.StdOut strValue = "" If Force <> True Then Force = False End If if Right(SrcKey,1) <> "\" Then SrcKey = SrcKey & "\" if Right(DestKey,1) <> "\" Then DestKey = DestKey & "\" ret = objReg.EnumValues(Hive,SrcKey,arrValueNames,arrValueTypes) For i= LBound(arrValueNames) To UBound(arrValueNames) 'StdOut.WriteLine "Value Name: " & arrValueNames(i) StdOut.WriteLine "Copying from: " & SrcKey & arrValueNames(i) StdOut.WriteLine "To : " & DestKey & arrValueNames(i) StdOut.Write " Value: " If (Not valueExists(Hive, DestKey, arrValueNames(i))) Or Force Then Select Case arrValueTypes(i) Case REG_SZ 'StdOut.WriteLine "Data Type: String" 'StdOut.WriteBlankLines(1) objReg.GetStringValue Hive, SrcKey, arrValueNames(i), strValue objReg.SetStringValue Hive, DestKey, arrValueNames(i), strValue StdOut.Write strValue Case REG_EXPAND_SZ 'StdOut.WriteLine "Data Type: Expanded String" 'StdOut.WriteBlankLines(1) objReg.GetExpandedStringValue Hive, SrcKey, arrValueNames(i), strValue objReg.SetExpandedStringValue Hive, DestKey, arrValueNames(i), strValue StdOut.Write strValue Case REG_BINARY 'StdOut.WriteLine "Data Type: Binary" 'StdOut.WriteBlankLines(1) objReg.GetBinaryValue Hive, SrcKey, arrValueNames(i), strValue objReg.SetBinaryValue Hive, DestKey, arrValueNames(i), strValue For Each x in strValue StdOut.Write Hex(x) & " " Next Case REG_DWORD 'StdOut.WriteLine "Data Type: DWORD" 'StdOut.WriteBlankLines(1) objReg.GetDWORDValue Hive, SrcKey, arrValueNames(i), strValue objReg.SetDWordValue Hive, DestKey, arrValueNames(i), strValue StdOut.Write Hex(strValue) Case REG_MULTI_SZ 'StdOut.WriteLine "Data Type: Multi String" 'StdOut.WriteBlankLines(1) objReg.GetMultiStringValue Hive, SrcKey, arrValueNames(i), strValue objReg.SetMultiStringValue Hive, DestKey, arrValueNames(i), strValue For Each x in strValue StdOut.Write x Next End Select StdOut.WriteLine "" End If '' Force Next ret = objReg.EnumKey(Hive,SrcKey,arrSubkeys) For i = LBound(arrSubkeys) to UBound(arrSubkeys) If Not keyExists(Hive,DestKey & arrSubkeys(i)) Then objReg.CreateKey Hive,DestKey & arrSubkeys(i) End If RegCopyTree Hive, SrcKey & arrSubkeys(i), DestKey & arrSubkeys(i), Force Next On Error Goto 0 End Function
This function takes the Hive, Source Key, Destination Key, and a Boolean Value to determine whether to Force overwriting existing values. It first creates the Destination key if it doesn’t already exist, then enumerates all values in the Source path, and writes them to the Destination path, creating new values or overwriting only if Force is set. This function has a lot of StdOut.Write calls to show the progress of the duplication. Running the script via CScript gives the following results:
Copying from: Software\Microsoft\Windows\CurrentVersion\Group Policy Objects\{678C8897-54AA-4FB9-AA72-6C227C287D12}Machine\Software\Policies\Microsoft\WindowsFirewall\StandardProfile\EnableFirewall
To : Software\Microsoft\Windows\CurrentVersion\Group Policy Objects\{678C8897-54AA-4FB9-AA72-6C227C287D12}Machine\Software\Policies\Microsoft\WindowsFirewall\DomainProfile\EnableFirewall
Value: 1
Copying from: Software\Microsoft\Windows\CurrentVersion\Group Policy Objects\{678C8897-54AA-4FB9-AA72-6C227C287D12}Machine\Software\Policies\Microsoft\WindowsFirewall\StandardProfile\AuthorizedApplications\Enabled
To : Software\Microsoft\Windows\CurrentVersion\Group Policy Objects\{678C8897-54AA-4FB9-AA72-6C227C287D12}Machine\Software\Policies\Microsoft\WindowsFirewall\DomainProfile\AuthorizedApplications\Enabled
Value: 1
...
This should simplify the time taken for duplicating from Standard to Domain profile. For future reference this has also made it far easier to import/export port/program exceptions from policies I am editing. In future I may incorporate this into my Group Policy Firewall Exceptions Excel Spreadsheet in VBA to allow writing updated policies to the Policy.
After running this the settings will be seen to have changed in the Group Policy Editor Window immediately. I have tested this and checked that the Logging file is not replaced by “…\standard.log” where it should be “…\domain.log”.
Cheers, Chris.
Attached: RegFirewallProfileDuplication.vbs
