Windows Azure – Restore Encrypted VM – BEK and KEK

When restoring an Encrypted Virtual Machine that is managed by Windows Azure, you will need to use PowerShell.

This is a two stage process.

Restore-BackupImageToDisk … | Restore-EncryptedBekVM …

Stage 1

Retrieve the Backup Container – This will contain the encrypted disks and json files with the secret keys.

  • keyEncryptionKey
  • diskEncryptionKey

This will allow you to retrieve the disks and JSON metadata in step 2.








Get-AzureRmSubscription -SubscriptionName $SubscriptionName | Select-AzureRmSubscription
$endDate = Get-Date

$namedContainer = Get-AzureRmRecoveryServicesBackupContainer  -ContainerType "AzureVM" -Status "Registered" | Where { $_.FriendlyName -eq $VMName }
$backupitem = Get-AzureRmRecoveryServicesBackupItem -Container $namedContainer  -WorkloadType "AzureVM"

$rp = Get-AzureRmRecoveryServicesBackupRecoveryPoint -Item $backupitem -StartDate $FromDate.ToUniversalTime() -EndDate $enddate.ToUniversalTime()
$restorejob = Restore-AzureRmRecoveryServicesBackupItem -RecoveryPoint $rp[0] -StorageAccountName $StorageAccount -StorageAccountResourceGroupName $ResourceGroup
Wait-AzureRmRecoveryServicesBackupJob -Job $restorejob -Timeout 43200
$restorejob = Get-AzureRmRecoveryServicesBackupJob -Job $restorejob
$details = Get-AzureRmRecoveryServicesBackupJobDetails -Job $restorejob

Stage 2

We will grab the job details via the pipeline if provided or go find the earliest Restore Job after the FromDate and then initiate a restore of all the encrypted disks to the new Virtual Machine.


    [Parameter(ValueFromPipeline=$True, Mandatory=$false, HelpMessage="Requires a AzureVmJobDetails object e.g. Get-AzureRmRecoveryServicesBackupJobDetails. Optional.")]

    [Parameter(Mandatory=$true, HelpMessage="Assumes osDisks, DataDisk, RestorePoints, AvailbilitySet, VM, Nic are all in same resource group.")]




Begin {
    $FromDate = $FromDate.ToUniversalTime()
    Write-Verbose "Started. $(Get-Date)"

Process {
	Write-Verbose "Retrieving Backup Vault."
	if(-not $JobDetails)
		Get-AzureRmRecoveryServicesVault -Name $BackupVaultName -ResourceGroupName $DefaultResourceGroup | Set-AzureRmRecoveryServicesVaultContext
		$Job = Get-AzureRmRecoveryServicesBackupJob -Status Completed -Operation Restore -From $FromDate | Sort -Property StartTime | Where { $_.WorkloadName -eq $SourceVMName} | Select -Last 1
		if($Job -eq $null) {
			throw "Job $workLoadName not found."
		$JobDetails = Get-AzureRmRecoveryServicesBackupJobDetails -Job $Job

	Write-Verbose "Query the restored disk properties for the job details."
	$properties = $
	$storageAccountName = $properties["Target Storage Account Name"]
	$containerName = $properties["Config Blob Container Name"]
	$blobName = $properties["Config Blob Name"]

	Write-Verbose "Found Restore Blob Set at $($Properties['Config Blob Uri'])"
	Write-Verbose "Set the Azure storage context and restore the JSON configuration file."

	Set-AzureRmCurrentStorageAccount -Name $storageaccountname -ResourceGroupName $DefaultResourceGroup
	$folder = New-Item "C:\RangerRom" -ItemType Directory -Force
	$destination_path = "C:\$($folder.Name)\$SourceVMName.config.json"
	Get-AzureStorageBlobContent -Container $containerName -Blob $blobName -Destination $destination_path
	Write-Verbose "Restore config saved to file. $destination_path"
	$restoreConfig = ((Get-Content -Path $destination_path -Raw -Encoding Unicode)).TrimEnd([char]0x00) | ConvertFrom-Json

	# 3. Use the JSON configuration file to create the VM configuration.
	$oldVM = Get-AzureRmVM | Where { $_.Name -eq $SourceVMName }
	$vm = New-AzureRmVMConfig -VMSize $restoreConfig.'properties.hardwareProfile'.vmSize -VMName $TargetVMName -AvailabilitySetId $oldVM.AvailabilitySetReference.Id
	$vm.Location = $oldVM.Location

	# 4. Attach the OS disk and data disks - Managed, encrypted VMs (BEK only
	$bekUrl = $restoreConfig.'properties.storageProfile'.osDisk.encryptionSettings.diskEncryptionKey.secretUrl
	$keyVaultId = $restoreConfig.'properties.storageProfile'
	$kekUrl = $restoreConfig.'properties.storageProfile'.osDisk.encryptionSettings.keyEncryptionKey.keyUrl
	$storageType = "StandardLRS"
	$osDiskName = $vm.Name + "_Restored_" + (Get-Date).ToString("yyyy-MM-dd-hh-mm-ss") + "_osdisk"
	$osVhdUri = $restoreConfig.'properties.storageProfile'.osDisk.vhd.uri
	$diskConfig = New-AzureRmDiskConfig -AccountType $storageType -Location $restoreConfig.location -CreateOption Import -SourceUri $osVhdUri
	$osDisk = New-AzureRmDisk -DiskName $osDiskName -Disk $diskConfig -ResourceGroupName $DefaultResourceGroup
	Set-AzureRmVMOSDisk -VM $vm -ManagedDiskId $osDisk.Id -DiskEncryptionKeyUrl $bekUrl -DiskEncryptionKeyVaultId $keyVaultId -KeyEncryptionKeyUrl $kekUrl -KeyEncryptionKeyVaultId $keyVaultId -CreateOption "Attach" -Windows

	$count = 0
	foreach($dd in $restoreConfig.'properties.storageProfile'.dataDisks)
		$dataDiskName = $vm.Name + "_Restored_" + (Get-Date).ToString("yyyy-MM-dd-hh-mm-ss") + "_datadisk" + $count ;
		$dataVhdUri = $dd.vhd.uri;
		$dataDiskConfig = New-AzureRmDiskConfig -AccountType $storageType -Location $restoreConfig.location -CreateOption Import -SourceUri $dataVhdUri
		$dataDisk = New-AzureRmDisk -DiskName $dataDiskName -Disk $dataDiskConfig -ResourceGroupName $DefaultResourceGroup
		Add-AzureRmVMDataDisk -VM $vm -Name $dataDiskName -ManagedDiskId $dataDisk.Id -Lun $dd.Lun -CreateOption "Attach"
		$count += 1

	Write-Verbose  "Setting the Network settings."

	$oldNicId = $oldVM.NetworkProfile.NetworkInterfaces[0].Id
	$oldNic = Get-AzureRmNetworkInterface -Name $oldNicId.Substring($oldNicId.LastIndexOf("/")+ 1) -ResourceGroupName $DefaultResourceGroup
	$subnetItems =  $oldNic.IpConfigurations[0].Subnet.Id.Split("/")
	$networkResourceGroup = $subnetItems[$subnetItems.IndexOf("resourceGroups")+1]
	$nicName= $vm.Name + "_nic_" + (New-Guid).Guid
	$nic = New-AzureRmNetworkInterface -Name $nicName -ResourceGroupName $networkResourceGroup -Location $oldNic.location -SubnetId $oldNic.IpConfigurations[0].Subnet.Id
	$vm=Add-AzureRmVMNetworkInterface -VM $vm -Id $nic.Id
	$vm.DiagnosticsProfile = $oldVM.DiagnosticsProfile

	Write-Verbose "Provisioning VM."
	New-AzureRmVM -ResourceGroupName $oldVM.ResourceGroupName -Location $oldVM.Location -VM $vm


End {
    Write-Verbose "Completed. $(Get-Date)"


.\Restore-BackupImageToDisk … | .\Restore-EncryptedBekVM.ps1 …


Ensure you have Azure VM Backups and they are backed on on a regular schedule.

Use this script to backup a Restore Point from a Recovery Vault Container.

Remember it will pick the earliest date of a Restore Point relative to your From Date. If there are 4 Restores in the recovery vault from 1 May, it will pick the first one.

Remember to:

  • Decommission the old VM
  • Update DNS with the new ip address
  • Update the Load Balance Sets (If using a Load Balancer)

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