Enable Federal Information Process Standard (FIPS) for Azure Kubernetes Service (AKS) node pools

The Federal Information Processing Standard (FIPS) 140-2 is a US government standard that defines minimum security requirements for cryptographic modules in information technology products and systems. Azure Kubernetes Service (AKS) allows you to create Linux and Windows node pools with FIPS 140-2 enabled. Deployments running on FIPS-enabled node pools can use those cryptographic modules to provide increased security and help meet security controls as part of FedRAMP compliance. For more information on FIPS 140-2, see Federal Information Processing Standard (FIPS) 140.

Prerequisites

• Azure CLI version 2.32.0 or later installed and configured. To find the version, run az --version. For more information about installing or upgrading the Azure CLI, see Install Azure CLI.

Limitations

• FIPS-enabled node pools have the following limitations:
  • FIPS-enabled node pools require Kubernetes version 1.19 and greater.
  • To update the underlying packages or modules used for FIPS, you must use Node Image Upgrade.
  • Container images on the FIPS nodes haven't been assessed for FIPS compliance.
  • Mounting of a CIFS share fails because FIPS disables some authentication modules. To work around this issue, see Errors when mounting a file share on a FIPS-enabled node pool.

Supported OS Versions

You can create FIPS-enabled node pools on all supported OS types, Linux and Windows. However, not all OS versions support FIPS-enabled nodepools. After a new OS version is released, there is typically a waiting period before it is FIPS compliant.

The below table includes the supported OS versions:

OS Type	OS SKU	FIPS Compliance
Linux	Ubuntu	Supported
Linux	Azure Linux	Supported
Windows	Windows Server 2019	Supported
Windows	Windows Server 2022	Supported

When requesting FIPS enabled Ubuntu, if the default Ubuntu version does not support FIPS, AKS will default to the most recent FIPS-supported version of Ubuntu. For example, Ubuntu 22.04 is default for Linux node pools. Since 22.04 does not currently support FIPS, AKS defaults to Ubuntu 20.04 for Linux FIPS-enabled nodepools.

Create a FIPS-enabled Linux node pool

1. Create a FIPS-enabled Linux node pool using the az aks nodepool add command with the --enable-fips-image parameter.

   az aks nodepool add \
       --resource-group myResourceGroup \
       --cluster-name myAKSCluster \
       --name fipsnp \
       --enable-fips-image
   

   Note

   You can also use the --enable-fips-image parameter with the az aks create command when creating a cluster to enable FIPS on the default node pool. When adding node pools to a cluster created in this way, you still must use the --enable-fips-image parameter when adding node pools to create a FIPS-enabled node pool.

2. Verify your node pool is FIPS-enabled using the az aks show command and query for the enableFIPS value in agentPoolProfiles.

   az aks show \
       --resource-group myResourceGroup \
       --name myAKSCluster \
       --query="agentPoolProfiles[].{Name:name enableFips:enableFips}" \
       -o table
   

   The following example output shows the fipsnp node pool is FIPS-enabled:

   Name       enableFips
   ---------  ------------
   fipsnp     True
   nodepool1  False  
   

3. List the nodes using the kubectl get nodes command.

   kubectl get nodes
   

   The following example output shows a list of the nodes in the cluster. The nodes starting with aks-fipsnp are part of the FIPS-enabled node pool.

   NAME                                STATUS   ROLES   AGE     VERSION
   aks-fipsnp-12345678-vmss000000      Ready    agent   6m4s    v1.19.9
   aks-fipsnp-12345678-vmss000001      Ready    agent   5m21s   v1.19.9
   aks-fipsnp-12345678-vmss000002      Ready    agent   6m8s    v1.19.9
   aks-nodepool1-12345678-vmss000000   Ready    agent   34m     v1.19.9
   

4. Run a deployment with an interactive session on one of the nodes in the FIPS-enabled node pool using the kubectl debug command.

   kubectl debug node/aks-fipsnp-12345678-vmss000000 -it --image=mcr.azk8s.cn/dotnet/runtime-deps:6.0
   

5. From the interactive session output, verify the FIPS cryptographic libraries are enabled. Your output should look similar to the following example output:

   root@aks-fipsnp-12345678-vmss000000:/# cat /proc/sys/crypto/fips_enabled
   1
   

FIPS-enabled node pools also have a kubernetes.azure.com/fips_enabled=true label, which deployments can use to target those node pools.

Create a FIPS-enabled Windows node pool

1. Create a FIPS-enabled Windows node pool using the az aks nodepool add command with the --enable-fips-image parameter. Unlike Linux-based node pools, Windows node pools share the same image set.

   az aks nodepool add \
       --resource-group myResourceGroup \
       --cluster-name myAKSCluster \
       --name fipsnp \
       --enable-fips-image \
       --os-type Windows
   

2. Verify your node pool is FIPS-enabled using the az aks show command and query for the enableFIPS value in agentPoolProfiles.

   az aks show \
       --resource-group myResourceGroup \
       --name myAKSCluster \
       --query="agentPoolProfiles[].{Name:name enableFips:enableFips}" \
       -o table
   

3. Verify Windows node pools have access to the FIPS cryptographic libraries, create an RDP connection to a Windows node in a FIPS-enabled node pool and check the registry.

4. Look for HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\FIPSAlgorithmPolicy in the registry.
5. If Enabled is set to 1, then FIPS is enabled.

FIPS-enabled node pools also have a kubernetes.azure.com/fips_enabled=true label, which deployments can use to target those node pools.

Update an existing node pool to enable or disable FIPS

Existing Linux node pools can be updated to enable or disable FIPS. If you are planning to migrate your node pools from non-FIPS to FIPS, first validate that your application is working properly in a test environment before migrating it to a production environment. Validating your application in a test environment should prevent issues caused by the FIPS kernel blocking some weak cipher or encryption algorithm, such as an MD4 algorithm that is not FIPS compliant.

Prerequisites

• Azure CLI version 2.64.0 or later. To find the version, run az --version. If you need to install or upgrade, see Install Azure CLI.

Enable FIPS on an existing node pool

Existing Linux node pools can be updated to enable FIPS. When you update an existing node pool, the node image will change from the current image to the recommended FIPS image of the same OS SKU.

1. Update a node pool using the [az aks nodepool update][az-aks-nodepool-update] command with the --enable-fips-image parameter.

   az aks nodepool update \
       --resource-group myResourceGroup \
       --cluster-name myAKSCluster \
       --name np \
       --enable-fips-image
   

The above command triggers a reimage of the node pool immediately to deploy the FIPS compliant Operating System. This reimage occurs during the node pool update. No additional steps are required.

2. Verify that your node pool is FIPS-enabled using the az aks show command and query for the enableFIPS value in agentPoolProfiles.

   az aks show \
       --resource-group myResourceGroup \
       --name myAKSCluster \
       --query="agentPoolProfiles[].{Name:name enableFips:enableFips}" \
       -o table
   

   The following example output shows that the np node pool is FIPS-enabled:

   Name       enableFips
   ---------  ------------
   np         True
   nodepool1  False  
   

3. List the nodes using the kubectl get nodes command.

   kubectl get nodes
   

   The following example output shows a list of the nodes in the cluster. The nodes starting with aks-np are part of the FIPS-enabled node pool.

   NAME                                STATUS   ROLES   AGE     VERSION
   aks-np-12345678-vmss000000          Ready    agent   6m4s    v1.19.9
   aks-np-12345678-vmss000001          Ready    agent   5m21s   v1.19.9
   aks-np-12345678-vmss000002          Ready    agent   6m8s    v1.19.9
   aks-nodepool1-12345678-vmss000000   Ready    agent   34m     v1.19.9
   

4. Run a deployment with an interactive session on one of the nodes in the FIPS-enabled node pool using the kubectl debug command.

   kubectl debug node/aks-np-12345678-vmss000000 -it --image=mcr.azk8s.cn/dotnet/runtime-deps:6.0
   

5. From the interactive session output, verify the FIPS cryptographic libraries are enabled. Your output should look similar to the following example output:

   root@aks-np-12345678-vmss000000:/# cat /proc/sys/crypto/fips_enabled
   1
   

FIPS-enabled node pools also have a kubernetes.azure.com/fips_enabled=true label, which deployments can use to target those node pools.

Disable FIPS on an existing node pool

Existing Linux node pools can be updated to disable FIPS. When updating an existing node pool, the node image will change from the current FIPS image to the recommended non-FIPS image of the same OS SKU. The node image change will occur after a reimage.

1. Update a Linux node pool using the [az aks nodepool update][az-aks-nodepool-update] command with the --disable-fips-image parameter.

   az aks nodepool update \
       --resource-group myResourceGroup \
       --cluster-name myAKSCluster \
       --name np \
       --disable-fips-image
   

The above command triggers a reimage of the node pool immediately to deploy the FIPS compliant Operating System. This reimage occurs during the node pool update. No additional steps are required.

2. Verify that your node pool is not FIPS-enabled using the az aks show command and query for the enableFIPS value in agentPoolProfiles.

   az aks show \
       --resource-group myResourceGroup \
       --name myAKSCluster \
       --query="agentPoolProfiles[].{Name:name enableFips:enableFips}" \
       -o table
   

   The following example output shows that the np node pool is not FIPS-enabled:

   Name       enableFips
   ---------  ------------
   np         False
   nodepool1  False  
   

Next steps

To learn more about AKS security, see Best practices for cluster security and upgrades in Azure Kubernetes Service (AKS).