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Quickstart: Create a confidential VM with the Azure CLI

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Applies to: ✔️ Linux VMs ✔️ Windows VMs

This quickstart shows you how to use the Azure Command-Line Interface (Azure CLI) to deploy a confidential virtual machine (confidential VM) in Azure. The Azure CLI is used to create and manage Azure resources via either the command line or scripts.

Prerequisites

If you don't have an Azure subscription, create a free Azure account before you begin.

Launch Azure Cloud Shell

Azure Cloud Shell is a free interactive shell that you can use to run the steps in this article. It has common Azure tools preinstalled and configured to use with your account.

To open the Cloud Shell, just select Try it from the upper right corner of a code block. You can also open Cloud Shell in a separate browser tab by going to https://shell.azure.com/bash. Select Copy to copy the blocks of code, paste it into the Cloud Shell, and select Enter to run it.

If you prefer to install and use the CLI locally, this quickstart requires Azure CLI version 2.38.0 or later. Run az--version to find the version. If you need to install or upgrade, see Install Azure CLI.

Create a resource group

Create a resource group with the az group create command. An Azure resource group is a logical container into which Azure resources are deployed and managed. The following example creates a resource group named myResourceGroup in the northeurope location:

Note

Confidential VMs are not available in all locations. For currently supported locations, see which VM products are available by Azure region.

az group create --name myResourceGroup --location northeurope

Create Confidential virtual machine using a platform-managed key

Create a VM with the az vm create command.

The following example creates a VM named myVM and adds a user account named azureuser. The --generate-ssh-keys parameter is used to automatically generate an SSH key, and put it in the default key location(~/.ssh). To use a specific set of keys instead, use the --ssh-key-values option. For size, select a confidential VM size. For more information, see supported confidential VM families.

Choose VMGuestStateOnly for no OS disk confidential encryption. Or, choose DiskWithVMGuestState for OS disk confidential encryption with a platform-managed key. Secure Boot is enabled by default, but is optional for VMGuestStateOnly. For more information, see secure boot and vTPM. For more information on disk encryption and encryption at host, see confidential OS disk encryption and encryption at host.

az vm create \
  --resource-group myResourceGroup \
  --name myVM \
  --size Standard_DC4es_v5 \
  --admin-username <azure-username> \
  --admin-password <azure-password> \
  --enable-vtpm true \
  --image "Canonical:0001-com-ubuntu-confidential-vm-jammy:22_04-lts-cvm:latest" \
  --public-ip-sku Standard \
  --security-type ConfidentialVM \
  --os-disk-security-encryption-type VMGuestStateOnly \
  --enable-secure-boot true \
  --encryption-at-host \

It takes a few minutes to create the VM and supporting resources. The following example output shows the VM create operation was successful.

{
  "fqdns": "",
  "id": "/subscriptions/<guid>/resourceGroups/myResourceGroup/providers/Microsoft.Compute/virtualMachines/myVM",
  "location": "northeurope",
  "macAddress": "<MAC-address>",
  "powerState": "VM running",
  "privateIpAddress": "10.20.255.255",
  "publicIpAddress": "192.168.255.255",
  "resourceGroup": "myResourceGroup",
  "zones": ""
}

Make a note of the publicIpAddress to use later.

Create Confidential virtual machine using a Customer Managed Key

To create a confidential disk encryption set, you have two options: Using Azure Key Vault or Azure Key Vault managed Hardware Security Module (HSM). Based on your security and compliance needs you can choose either option. However, it is important to note that the standard SKU is not supported. The following example uses Azure Key Vault Premium.

  1. Grant confidential VM Service Principal Confidential VM Orchestrator to tenant. For this step you need to be a Global Admin or you need to have the User Access Administrator RBAC role. Install Microsoft Graph SDK to execute the commands below.
Connect-Graph -Tenant "your tenant ID" Application.ReadWrite.All
New-MgServicePrincipal -AppId bf7b6499-ff71-4aa2-97a4-f372087be7f0 -DisplayName "Confidential VM Orchestrator"
  1. Create an Azure Key Vault using the az keyvault create command. For the pricing tier, select Premium (includes support for HSM backed keys). Make sure that you have an owner role in this key vault.
az keyvault create -n keyVaultName -g myResourceGroup --enabled-for-disk-encryption true --sku premium --enable-purge-protection true
  1. Give Confidential VM Orchestrator permissions to get and release the key vault.
$cvmAgent = az ad sp show --id "bf7b6499-ff71-4aa2-97a4-f372087be7f0" | Out-String | ConvertFrom-Json
az keyvault set-policy --name keyVaultName --object-id $cvmAgent.Id --key-permissions get release
  1. Create a key in the key vault using az keyvault key create. For the key type, use RSA-HSM.
az keyvault key create --name mykey --vault-name keyVaultName --default-cvm-policy --exportable --kty RSA-HSM
  1. Create the disk encryption set using az disk-encryption-set create. Set the encryption type to ConfidentialVmEncryptedWithCustomerKey.
$keyVaultKeyUrl=(az keyvault key show --vault-name keyVaultName --name mykey--query [key.kid] -o tsv)

az disk-encryption-set create --resource-group myResourceGroup --name diskEncryptionSetName --key-url $keyVaultKeyUrl  --encryption-type ConfidentialVmEncryptedWithCustomerKey
  1. Grant the disk encryption set resource access to the key vault using az key vault set-policy.
$desIdentity=(az disk-encryption-set show -n diskEncryptionSetName -g myResourceGroup --query [identity.principalId] -o tsv)

az keyvault set-policy -n keyVaultName -g myResourceGroup --object-id $desIdentity --key-permissions wrapkey unwrapkey get
  1. Use the disk encryption set ID to create the VM.
$diskEncryptionSetID=(az disk-encryption-set show -n diskEncryptionSetName -g myResourceGroup --query [id] -o tsv)
  1. Create a VM with the az vm create command. Choose DiskWithVMGuestState for OS disk confidential encryption with a customer-managed key. Enabling secure boot is optional, but recommended. For more information, see secure boot and vTPM. For more information on disk encryption, see confidential OS disk encryption.
az vm create \
--resource-group myResourceGroup \
--name myVM \
--size Standard_DC4as_v5 \
--admin-username <azure-user> \
--admin-password <azure-password> \
--enable-vtpm true \
--enable-secure-boot true \
--image "Canonical:0001-com-ubuntu-confidential-vm-focal:20_04-lts-cvm:latest" \
--public-ip-sku Standard \
--security-type ConfidentialVM \
--os-disk-security-encryption-type DiskWithVMGuestState \
--os-disk-secure-vm-disk-encryption-set $diskEncryptionSetID \

It takes a few minutes to create the VM and supporting resources. The following example output shows the VM create operation was successful.

{
  "fqdns": "",
  "id": "/subscriptions/<guid>/resourceGroups/myResourceGroup/providers/Microsoft.Compute/virtualMachines/myVM",
  "location": "eastus",
  "macAddress": "<MAC-address>",
  "powerState": "VM running",
  "privateIpAddress": "10.20.255.255",
  "publicIpAddress": "192.168.255.255",
  "resourceGroup": "myResourceGroup",
  "zones": ""
}

Make a note of the publicIpAddress to use later.

Connect and attest the AMD-based CVM through Microsoft Azure Attestation Sample App

To use a sample application in C++ for use with the guest attestation APIs, use the following steps. This example uses a Linux confidential virtual machine. For Windows, see build instructions for Windows.

  1. Sign in to your confidential VM using its public IP address.

  2. Clone the sample Linux application.

  3. Install the build-essential package. This package installs everything required for compiling the sample application.

sudo apt-get install build-essential
  1. Install the packages below.
sudo apt-get install libcurl4-openssl-dev
sudo apt-get install libjsoncpp-dev
sudo apt-get install libboost-all-dev
sudo apt install nlohmann-json3-dev

  1. Download the attestation package.

  2. Install the attestation package. Make sure to replace <version> with the version that you downloaded.

sudo dpkg -i azguestattestation1_<latest-version>_amd64.deb
  1. Once the above packages have been installed, use the below steps to build and run the app.
cd confidential-computing-cvm-guest-attestation/cvm-attestation-sample-app
sudo cmake . && make
sudo ./AttestationClient -o token
  1. To convert the web token to a JSON, use the steps below.
sudo ./AttestationClient -o token>> /attestation_output

JWT=$(cat /attestation_output)

echo -n $JWT | cut -d "." -f 1 | base64 -d 2>/dev/null | jq .
echo -n $JWT | cut -d "." -f 2 | base64 -d 2>/dev/null | jq .

Next steps

Create a confidential VM with an ARM template