Categories
Random

Azure Virtual Secure Administration Workstation – Part 4 – Configuring Entra SSO

Azure Secure Admin Workstation posts:


Context and References

Troubleshooting and Errors

  • After not being able to sign in with an Entra user, took a look at:

Error: Unable to connect right now

  • Likely related to the AVD VM’s ability to talk to required Entra endpoints
    • An easy way to validate this is to add a temporary allow all outbound TLS
Categories
ITOps

Azure Virtual Secure Administration Workstation – Part 3 – Session hosts and access

Azure Secure Admin Workstation posts:


Context

In the interest of enabling source control and potentially automation, the deployment is conducted using PowerShell commands. In this example I am using Azure CloudShell, for manual and exploratory activities it is handy as it is secure, includes all required modules, removes any authentication faff.

  • If you want to create Microsoft Entra joined session hosts, we only support this using the Azure portal with the Azure Virtual Desktop service. (Add session hosts to a host pool | Microsoft Learn)
  • You can create session hosts and register them to a host pool in a single end-to-end process with the Azure Virtual Desktop service using the Azure portal or an ARM template. You can find some example ARM templates in our GitHub repo

Reference Materials

Key Terms

Deployment Procedure

When using Azure CLI or Azure PowerShell you’ll need to create the virtual machines outside of Azure Virtual Desktop, then add them as session hosts to a host pool separately.

  1. Add members to the saw_user_group
  2. Generate a registration key
    • When you add session hosts to a host pool, first you’ll need to generate a registration key. A registration key needs to be generated per host pool and it authorizes session hosts to join that host pool. It’s only valid for the duration you specify. If an existing registration key has expired, you can also use these steps to generate a new key.
  3. Create and register session hosts with the Azure Virtual Desktop service

Add Entra joined Session Host

Following is direct from Add session hosts to a host pool – Azure Virtual Desktop | Microsoft Learn:

  1. Sign in to the Azure portal.
  2. In the search bar, enter Azure Virtual Desktop and select the matching service entry.
  3. Select Host pools, then select the name of the host pool you want to add session hosts to.
  4. On the host pool overview, select Session hosts, then select + Add.
  5. The Basics tab will be greyed out because you’re using the existing host pool. Select Next: Virtual Machines.
  6. On the Virtual machines tab, complete the following information:
  • (this is for our use case and assumes you followed Part 1, of course customise this as appropriate)
    • Name prefix: SAW
    • Availability options: No infrastructure redundancy required
    • Security Type: Trusted launch virtual machines
    • Enable secure boot: True
    • Enable vTPM: True
    • Integrity monitoring: True
    • Image: Latest Windows 11 Enterprise multi-session
      • If we select Personal instead of Pooled in Part 1, we would have non-Enterprise options here…
    • Virtual machine size, Number of VMs, OS disk type
      • Use case dependent with no impact on procedure/security
    • Boot diagnostics: Enabled with managed storage account
    • Network and security
      • Virtual Network: SAWVnet
      • Subnet: SAWSubNet
      • Network security group type: Basic
      • Public inbound ports: No
    • Domain to join
      • Select which directory you would like to join: Microsoft Entra ID
      • Enroll VM with Intune: Yes
    • Virtual machine administrator account
      • Required for Azure to provision the VM, once it joins Entra and Intune your Configuration Profile should remove the local administrator
    • Custom configuration
      • Custom configuration script url: None for now…
  • Tags?
    • Suggest adding ‘ResougeTag:AzureSAW’ for now… tags can be handy
  • Download a template for automation, suggest doing this as a default behaviour
  • Create!

Post Host Deployment

  • After launching your first Session Host, Azure will take several (20?!) mins to deploy the session host and add it to the Host Pool. You can verify this was successful via Host pools – Microsoft Azure:

Enable Entra ID SSO

Troubleshooting

Disk Encryption???

PowerShell

RAW_https://raw.githubusercontent.com/zoak-solutions/AzureVirtualSAW/master/scripts/CreateRegKey.ps1
RAW_https://raw.githubusercontent.com/zoak-solutions/AzureVirtualSAW/master/scripts/AddMembersToGroup.ps1

Connect to my Azure Virtual SAW!

Extras

Set up Azure Virtual Desktop Client

  1. Download and install the Client App (or deploy to users via Add Microsoft Store apps to Microsoft Intune | Microsoft Learn)
  2. Run it, on first run, assuming you installed unconfigured from the MS store you will be asked to subscribe (do this with your SAW access user)
    • …. Thats it… you will see Session Host to connected to if all worked!
  3. Noting that Entra SSO was not working for me so… Part 4 – Configuring Entra SSO

Validate Session Host can talk to required Azure endpoints

You can validate that your session host VMs can connect to these URLs by following the steps to run the Required URL Check tool.

Categories
ITOps

Azure Virtual Secure Administration Workstation – Part 2 – Firewalls and VNets

Azure Secure Admin Workstation posts:


Context and References

Deployment procedure

Stage 2 – Create Azure Network Components

  • This section provides context for the PowerShell commands are below… strongly suggest reviewing description of steps first.

Procedure

Primary source for this bit: Deploy and configure Azure Firewall using Azure PowerShell | Microsoft Learn

  • Noting Azure states that for ‘production’ deployments, a hub and spoke model is recommended, where the firewall is in its own VNet.
    • For our use case, I don’t believe the hub and spoke model will provide any benefit regarding security or otherwise.
  1. Create a Vnet and add FWsubnet + SAWsubnet
    • NOTE: The AzureFWSubnet must be a /26
  2. Create a Public IP Address for the Azure FW and deploy the firewall
  3. Create a route table and associate routes to SAW subnet ensuring SAW traffic is routed via the Azure Firewall
  4. Create rules for outbound internet connectivity, some MS doc still has commands for deploying Application and Network firewall rules directly on the Azure Firewall despite the Azure Well-Architected Framework review – Azure Firewall | Microsoft Learn stating that Azure Firewall Manager and Policies should be used
    • … so the PowerShell script below has been updated to create an Azure Firewall Policy instead of assigning rules directly to the firewall

PowerShell

RAW_https://raw.githubusercontent.com/zoak-solutions/AzureVirtualSAW/master/scripts/CreateSAWNets.ps1
Categories
ITOps

Azure Virtual Secure Administration Workstation – Part 1 – VDI Environment

Azure Secure Admin Workstation posts:


Context

We have numerous clients and our own systems that require:

  • Access only from appropriately hardened and monitored hosts
  • Inbound and outbound network security including the ability to ‘AllowList’ and ‘BlockList’ based on IPs/URLs/Hostnames/other ‘NGFW‘ methods… although this can be achieved with host-based only controls… does not seems like a very layered defence.
  • Idempotent deployment solution (deployment code can be run regularly and if no changes to code, no changes to deployment)
    • PowerShell is not ideal for doing idempotency proper… but it can, will see how I go for time.

In the interest of enabling source control and potentially automation, the deployment is conducted using PowerShell commands. In this example I am using Azure CloudShell, for manual and exploratory activities it is handy as it is secure, includes all required modules, removes any authentication faff.

At this stage I am not sure how much additional protection / value adding Azure Firewall to the environment will add… will add it for now and find out! Microsoft’s doc doesn’t make the benefits very clear for me:

  • A host pool is a collection of Azure virtual machines that register to Azure Virtual Desktop as session hosts. These virtual machines run in your virtual network and are subject to the virtual network security controls. They need outbound Internet access to the Azure Virtual Desktop service to operate properly and might also need outbound Internet access for end users. Azure Firewall can help you lock down your environment and filter outbound traffic. (Use Azure Firewall to protect Azure Virtual Desktop | Microsoft Learn)
  • The diagram below shows a suggested architecture, going to try avoid getting stuck without a required component later and stay somewhat close to this. Though it should be noted that a potentially valid architecture is just a SAWVnet as inbound connectivity is managed by Azure (via the AVD Instructure: Users connecting to Azure Virtual Desktop securely establish a reverse connection to the service, which means you don’t need to open any inbound ports. (Azure Virtual Desktop | Microsoft Learn)

Reference Material

Key Terms

  • Resource groups: Logical containers that you use to group related resources in a subscription. Each resource can exist in only one resource group. Resource groups allow for more granular grouping within a subscription. They’re commonly used to represent a collection of assets that are required to support a workload, application, or specific function within a subscription.
  • Host pools: A host pool is a collection of Azure virtual machines that register to Azure Virtual Desktop as session hosts when you run the Azure Virtual Desktop agent. All session host virtual machines in a host pool should be sourced from the same image for a consistent user experience. You control the resources published to users through application groups. A host pool can be one of two types:
    • Personal, where each session host is assigned to an individual user. Personal host pools provide dedicated desktops to end-users that optimize environments for performance and data separation.
    • Pooled, where user sessions can be load balanced to any session host in the host pool. There can be multiple different users on a single session host at the same time. Pooled host pools provide a shared remote experience to end-users, which ensures lower costs and greater efficiency.
  • Application groups: An application group is a logical grouping of applications installed on session hosts in the host pool. An application group can be one of two types:
    • RemoteApp, where users access the applications you individually select and publish to the application group. Available with pooled host pools only.
    • Desktop, where users access the full desktop. Available with pooled or personal host pools.
    • NOTE: We don’t support assigning both the RemoteApp and desktop application groups in a single host pool to the same user.
  • Workspaces: logical grouping of application groups in Azure Virtual Desktop. Each Azure Virtual Desktop application group must be associated with a workspace for users to see the desktops and applications published to them.
  • Desktop Virtualization User: Built-in Azure RBAC roles Azure Virtual Desktop | Microsoft Learn

Out of scope

Deployment procedure

Stage 1 – Create Azure Virtual Desktop Environment

  • This section provides context for the PowerShell commands are below… strongly suggest reviewing description of steps first.

Azure Virtual Desktop Environment

  1. Prerequisites for Azure Virtual Desktop | Microsoft Learn
  2. Launch the Azure Cloud Shell in the Azure portal with the PowerShell terminal type
  3. Create a Resource Group
    • Parameters:
      • Name, Location
  4. Create a Host Pool
    • Use the New-AzWvdHostPool cmdlet with the following examples to create a host pool. More parameters are available; for more information, see the New-AzWvdHostPool PowerShell reference.
    • Parameters:
      • Location: must be one of LocationNames Class (Microsoft.Azure.Documents) and match your Resource Group
      • HostPoolType: can be one of two types:
        • Personal, where each session host is assigned to an individual user. Personal host pools provide dedicated desktops to end-users that optimize environments for performance and data separation.
        • Pooled, where user sessions can be load balanced to any session host in the host pool. There can be multiple different users on a single session host at the same time. Pooled host pools provide a shared remote experience to end-users, which ensures lower costs and greater efficiency.
        • See also: Azure Virtual Desktop terminology – Azure | Microsoft Learn
  5. Create a workspace
    • Parameters:
      • Name, Location, ResourceGroupName
  6. Create an Application Group
    • Name, ResourceGroupName, Location
    • HostPoolArmPath: Azure Resource Manager Path
    • ApplicationGroupType: As above, RemoteApp / Desktop
  7. Add Application Group to Workspace
  8.  Create Entra User Group if it doesn’t exist
  9. Assign Entra Group to an Application Group

Next Steps:

PowerShell Script

RAW_https://raw.githubusercontent.com/zoak-solutions/AzureVirtualSAW/master/scripts/CreateAzureVDIEnv.ps1

Sundry

Upload and Run PowerShell script in CloudShell

  1. Configure CloudShell
  2. Open CloudShell – https://portal.azure.com/#cloudshell
  3. Upload your script using the upload button
    • File is now persistent in your CloudShell home dir

Rules for Azure FW protecting Azure Virtual Desktop

RAW_https://raw.githubusercontent.com/zoak-solutions/AzureVirtualSAW/master/config/EXAMPLE_SAWDeployerConfigItems.ps1