XMLOps/New-HashLevelRules.psm1
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Function New-HashLevelRules { <# .SYNOPSIS Creates new Hash level rules in an XML file For each hash data, it creates 2 Hash rules, one for Authenticode SHA2-256 and one for SHA1 hash It also adds the FileRulesRef for each hash to the ProductSigners node of the correct signing scenario (Kernel/User mode) .PARAMETER Hashes The Hashes to be used for creating the rules, they are the output of the Build-SignerAndHashObjects function .PARAMETER XmlFilePath The path to the XML file to be modified .INPUTS PSCustomObject[] System.IO.FileInfo .OUTPUTS System.Void #> [CmdletBinding()] [OutputType([System.Void])] Param( [Parameter(Mandatory = $true)][PSCustomObject[]]$Hashes, [Parameter(Mandatory = $true)][System.IO.FileInfo]$XmlFilePath ) Begin { . "$([WDACConfig.GlobalVars]::ModuleRootPath)\CoreExt\PSDefaultParameterValues.ps1" Write-Verbose -Message "New-HashLevelRules: There are $($Hashes.Count) Hash rules to be added to the XML file" # Load the XML file [System.Xml.XmlDocument]$Xml = Get-Content -Path $XmlFilePath # Define the namespace manager [System.Xml.XmlNamespaceManager]$Ns = New-Object -TypeName System.Xml.XmlNamespaceManager -ArgumentList $Xml.NameTable $Ns.AddNamespace('ns', 'urn:schemas-microsoft-com:sipolicy') # Find the ProductSigners Nodes [System.Xml.XmlElement]$UMCI_ProductSigners_Node = $Xml.SelectSingleNode('//ns:SigningScenarios/ns:SigningScenario[@Value="12"]/ns:ProductSigners', $Ns) [System.Xml.XmlElement]$KMCI_ProductSigners_Node = $Xml.SelectSingleNode('//ns:SigningScenarios/ns:SigningScenario[@Value="131"]/ns:ProductSigners', $Ns) } Process { # Find the FileRules node [System.Xml.XmlElement]$FileRulesNode = $Xml.SelectSingleNode('//ns:FileRules', $Ns) # Loop through each hash and create a new rule for it Foreach ($Hash in $Hashes) { [System.String]$Guid = [System.Guid]::NewGuid().ToString().replace('-', '').ToUpper() # Create a unique ID for the rule [System.String]$HashSHA256RuleID = "ID_ALLOW_A_$Guid" [System.String]$HashSHA1RuleID = "ID_ALLOW_B_$Guid" # Create new Allow Hash rule for Authenticode SHA256D [System.Xml.XmlElement]$NewAuth256HashNode = $Xml.CreateElement('Allow', $FileRulesNode.NamespaceURI) $NewAuth256HashNode.SetAttribute('ID', $HashSHA256RuleID) $NewAuth256HashNode.SetAttribute('FriendlyName', "$($Hash.FileName) Hash Sha256") $NewAuth256HashNode.SetAttribute('Hash', $Hash.AuthenticodeSHA256) # Add the new node to the FileRules node [System.Void]$FileRulesNode.AppendChild($NewAuth256HashNode) # Create new Allow Hash rule for Authenticode SHA1 [System.Xml.XmlElement]$NewAuth1HashNode = $Xml.CreateElement('Allow', $FileRulesNode.NamespaceURI) $NewAuth1HashNode.SetAttribute('ID', $HashSHA1RuleID) $NewAuth1HashNode.SetAttribute('FriendlyName', "$($Hash.FileName) Hash Sha1") $NewAuth1HashNode.SetAttribute('Hash', $Hash.AuthenticodeSHA1) # Add the new node to the FileRules node [System.Void]$FileRulesNode.AppendChild($NewAuth1HashNode) # For User-Mode files if ($Hash.SiSigningScenario -eq '1') { # Check if FileRulesRef node exists, if not, create it $UMCI_Temp_FileRulesRefNode = $UMCI_ProductSigners_Node.SelectSingleNode('ns:FileRulesRef', $Ns) if ($Null -eq $UMCI_Temp_FileRulesRefNode) { [System.Xml.XmlElement]$UMCI_Temp_FileRulesRefNode = $Xml.CreateElement('FileRulesRef', $Ns.LookupNamespace('ns')) [System.Void]$UMCI_ProductSigners_Node.AppendChild($UMCI_Temp_FileRulesRefNode) } # Create FileRuleRef for Authenticode SHA256 Hash inside the <FileRulesRef> -> <ProductSigners> -> <SigningScenario Value="12"> [System.Xml.XmlElement]$NewUMCIFileRuleRefNode = $Xml.CreateElement('FileRuleRef', $UMCI_Temp_FileRulesRefNode.NamespaceURI) $NewUMCIFileRuleRefNode.SetAttribute('RuleID', $HashSHA256RuleID) [System.Void]$UMCI_Temp_FileRulesRefNode.AppendChild($NewUMCIFileRuleRefNode) # Create FileRuleRef for Authenticode SHA1 Hash inside the <FileRulesRef> -> <ProductSigners> -> <SigningScenario Value="12"> [System.Xml.XmlElement]$NewUMCIFileRuleRefNode = $Xml.CreateElement('FileRuleRef', $UMCI_Temp_FileRulesRefNode.NamespaceURI) $NewUMCIFileRuleRefNode.SetAttribute('RuleID', $HashSHA1RuleID) [System.Void]$UMCI_Temp_FileRulesRefNode.AppendChild($NewUMCIFileRuleRefNode) } # For Kernel-Mode files elseif ($Hash.SiSigningScenario -eq '0') { # Display a warning if a hash rule for a kernel-mode file is being created and the file is not an MSI # Since MDE does not record the Signing information events (Id 8038) for MSI files so we must create Hash based rules for them if (-NOT $Hash.FileName.EndsWith('.msi')) { Write-Warning -Message "Creating Hash rule for Kernel-Mode file: $($Hash.FileName). Kernel-Mode file should be signed!" } # Check if FileRulesRef node exists, if not, create it $KMCI_Temp_FileRulesRefNode = $KMCI_ProductSigners_Node.SelectSingleNode('ns:FileRulesRef', $Ns) if ($Null -eq $KMCI_Temp_FileRulesRefNode) { [System.Xml.XmlElement]$KMCI_Temp_FileRulesRefNode = $Xml.CreateElement('FileRulesRef', $Ns.LookupNamespace('ns')) [System.Void]$KMCI_ProductSigners_Node.AppendChild($KMCI_Temp_FileRulesRefNode) } # Create FileRuleRef for Authenticode SHA256 Hash inside the <FileRulesRef> -> <ProductSigners> -> <SigningScenario Value="131"> [System.Xml.XmlElement]$NewKMCIFileRuleRefNode = $Xml.CreateElement('FileRuleRef', $KMCI_Temp_FileRulesRefNode.NamespaceURI) $NewKMCIFileRuleRefNode.SetAttribute('RuleID', $HashSHA256RuleID) [System.Void]$KMCI_Temp_FileRulesRefNode.AppendChild($NewKMCIFileRuleRefNode) # Create FileRuleRef for Authenticode SHA1 Hash inside the <FileRulesRef> -> <ProductSigners> -> <SigningScenario Value="131"> [System.Xml.XmlElement]$NewKMCIFileRuleRefNode = $Xml.CreateElement('FileRuleRef', $KMCI_Temp_FileRulesRefNode.NamespaceURI) $NewKMCIFileRuleRefNode.SetAttribute('RuleID', $HashSHA1RuleID) [System.Void]$KMCI_Temp_FileRulesRefNode.AppendChild($NewKMCIFileRuleRefNode) } } } End { $Xml.Save($XmlFilePath) } } Export-ModuleMember -Function 'New-HashLevelRules' |