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

Article
03/13/2024

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. Run az --version to find the version. For more information about installing or upgrading the Azure CLI, see Install Azure CLI.

Note

AKS Monitoring Addon supports FIPS enabled node pools with Ubuntu, Azure Linux, and Windows starting with Agent version 3.1.17 (Linux) and Win-3.1.17 (Windows).

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.

Important

The FIPS-enabled Linux image is a different image than the default Linux image used for Linux-based node pools. To enable FIPS on a node pool, you must create a new Linux-based node pool. You can't enable FIPS on existing node pools.

FIPS-enabled node images may have different version numbers, such as kernel version, than images that aren't FIPS-enabled. The update cycle for FIPS-enabled node pools and node images may differ from node pools and images that aren't FIPS-enabled.

Create a FIPS-enabled Linux node pool

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.

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

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

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.microsoft.com/dotnet/runtime-deps:6.0
```
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

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
```

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

Verify Windows node pools have access to the FIPS cryptographic libraries by creating an RDP connection to a Windows node in a FIPS-enabled node pool and check the registry. From the Run application, enter regedit.
Look for HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\FIPSAlgorithmPolicy in the registry.
If Enabled is set to 1, then FIPS is enabled.

Screenshot shows a picture of the registry editor to the FIPS Algorithm Policy, and it being enabled.

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

Next steps

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