internal/functions/New-MigrationTable.ps1
function New-MigrationTable { <# .SYNOPSIS Creates a new migration table used for GPO imports. .DESCRIPTION Creates a new migration table used for GPO imports. In this table, all source identities get matched to fitting destination identities. This ensures, that all identity references within GPOs remain intact. .PARAMETER Path The path where to spawn the migration table. Specify a folder, the file will be named '<DomainName>.migtable' .PARAMETER BackupPath The path where the GPO backups are stored. .PARAMETER Domain The domain the backup will be restored to. Defaults to the current user's domain. .EXAMPLE PS C:\> New-MigrationTable -Path '.' -BackupPath '.' Creates a migration table in the current path and looks in the current path for backup folders. #> [Diagnostics.CodeAnalysis.SuppressMessageAttribute("PSUseShouldProcessForStateChangingFunctions", "")] [CmdletBinding()] param ( [Parameter(Mandatory = $true)] [string] $Path, [Parameter(Mandatory = $true)] [string] $BackupPath, [string] $Domain = $env:USERDNSDOMAIN ) begin { $resolvedPath = (Resolve-Path $Path).ProviderPath $resolvedBackupPath = (Resolve-Path $BackupPath).ProviderPath $writePath = Join-Path -Path $resolvedPath -ChildPath "$Domain.migtable" #region Resolving source and destination Domain Names $domainData = Get-DomainData -Domain $Domain $destDomainDNS = $domainData.Fqdn $destDomainNetBios = $domainData.ADObject.NetBIOSName if ($script:sourceDomainData) { $sourceDomainDNS = $script:sourceDomainData.DomainDNSName $sourceDomainNetBios = $script:sourceDomainData.NetBIOSName } elseif ($script:identityMapping.Count -gt 0) { $sourceDomainDNS = $script:identityMapping[0].DomainFqdn $sourceDomainNetBios = $script:identityMapping[0].DomainName } else { throw "Unable to determine source domain. Run Import-GptDomainData or Import-GptIdentity first!" } #endregion Resolving source and destination Domain Names #region Preparing imported identities $explicitIdentityMappings = foreach ($identity in $script:identityMapping) { if (($identity.IsBuiltIn -eq 'True') -and ($identity.SID -like "*-32-*")) { [PSCustomObject]@{ Source = $identity.Name Target = $identity.Target } } else { [PSCustomObject]@{ Source = ('{0}\{1}' -f $identity.DomainName, $identity.Name) Target = ('{0}\{1}' -f $identity.TargetDomain.Name, $identity.Target) } [PSCustomObject]@{ Source = ('{0}@{1}' -f $identity.Name, $identity.DomainFqdn) Target = ('{0}@{1}' -f $identity.Target, $identity.TargetDomain.DNSRoot) } } } #endregion Preparing imported identities } process { #region Preparing basic migration table $groupPolicyManager = New-Object -ComObject GPMgmt.GPM $migrationTable = $groupPolicyManager.CreateMigrationTable() $constants = $groupPolicyManager.getConstants() $backupDirectory = $groupPolicyManager.GetBackupDir($resolvedBackupPath) $backupList = $backupDirectory.SearchBackups($groupPolicyManager.CreateSearchCriteria()) foreach ($policyBackup in $backupList) { $migrationTable.Add(0, $policyBackup) $migrationTable.Add($constants.ProcessSecurity, $policyBackup) } #endregion Preparing basic migration table #region Applying identity and UNC mappings foreach ($entry in $migrationTable.GetEntries()) { switch ($entry.EntryType) { $constants.EntryTypeUNCPath { if ($entry.Source -like "\\$sourceDomainDNS\*") { $null = $migrationTable.UpdateDestination($entry.Source, $entry.Source.Replace("\\$sourceDomainDNS\", "\\$destDomainDNS\")) } if ($entry.Source -like "\\$sourceDomainNetBios\*") { $null = $migrationTable.UpdateDestination($entry.Source, $entry.Source.Replace("\\$sourceDomainNetBios\", "\\$destDomainNetBios\")) } } { $constants.EntryTypeUser, $constants.EntryTypeGlobalGroup, $constants.EntryTypeUniversalGroup, $constants.EntryTypeUnknown -contains $_ } { if ($mapping = $explicitIdentityMappings | Where-Object Source -EQ $entry.Source) { $null = $migrationTable.UpdateDestination($entry.Source, $mapping.Target) } } } } # Additionally scan backup for share mappings, as those won't be found by default foreach ($gpoFolder in (Get-ChildItem -Path $resolvedBackupPath -Directory | Where-Object Name -Match '^(\{{0,1}([0-9a-fA-F]){8}-([0-9a-fA-F]){4}-([0-9a-fA-F]){4}-([0-9a-fA-F]){4}-([0-9a-fA-F]){12}\}{0,1})$')) { $driveXmlPath = Join-Path -Path $gpoFolder.FullName -ChildPath 'DomainSysvol\GPO\User\Preferences\Drives\Drives.xml' if (-not (Test-Path -Path $driveXmlPath)) { continue } try { $driveXmlData = [xml](Get-Content -Path $driveXmlPath) } catch { continue } foreach ($driveSet in $driveXmlData.Drives.Drive) { if ($driveSet.Properties.Path -like "\\$sourceDomainDNS\*") { $null = $migrationTable.AddEntry($driveSet.Properties.Path, $constants.EntryTypeUNCPath, $driveSet.Properties.Path.Replace("\\$sourceDomainDNS\", "\\$destDomainDNS\")) } if ($driveSet.Properties.Path -like "\\$sourceDomainNetBios\*") { $null = $migrationTable.AddEntry($driveSet.Properties.Path, $constants.EntryTypeUNCPath, $driveSet.Properties.Path.Replace("\\$sourceDomainNetBios\", "\\$destDomainNetBios\")) } } } #endregion Applying identity and UNC mappings $migrationTable.Save($writePath) $writePath } } |