Chapter 2. Support for FIPS cryptography
Starting with version 4.3, you can install an OpenShift Container Platform cluster that uses FIPS Validated / Modules in Process cryptographic libraries.
For the Red Hat Enterprise Linux CoreOS (RHCOS) machines in your cluster, this change is applied when the machines are deployed based on the status of an option in the
install-config.yaml file, which governs the cluster options that a user can change during cluster deployment. With Red Hat Enterprise Linux machines, you must enable FIPS mode when you install the operating system on the machines that you plan to use as worker machines. These configuration methods ensure that your cluster meet the requirements of a FIPS compliance audit: only FIPS Validated / Modules in Process cryptography packages are enabled before the initial system boot.
Because FIPS must be enabled before the operating system that your cluster uses boots for the first time, you cannot enable FIPS after you deploy a cluster.
2.1. FIPS validation in OpenShift Container Platform
OpenShift Container Platform uses certain FIPS Validated / Modules in Process modules within Red Hat Enterprise Linux (RHEL) and RHCOS for the operating system components that it uses. See RHEL7 core crypto components. For example, when users SSH into OpenShift Container Platform clusters and containers, those connections are properly encrypted.
OpenShift Container Platform components are written in Go and built with Red Hat’s golang compiler. When you enable FIPS mode for your cluster, all OpenShift Container Platform components that require cryptographic signing call RHEL and RHCOS cryptographic libraries.
Table 2.1. FIPS mode attributes and limitations in OpenShift Container Platform 4.4
FIPS support in RHEL 7 operating systems.
The FIPS implementation does not offer a single function that both computes hash functions and validates the keys that are based on that hash. This limitation will continue to be evaluated and improved in future OpenShift Container Platform releases.
FIPS support in CRI-O runtimes.
FIPS support in OpenShift Container Platform services.
FIPS Validated / Modules in Process cryptographic module and algorithms that are obtained from RHEL 7 and RHCOS binaries and images.
Use of FIPS compatible golang compiler.
TLS FIPS support is not complete but is planned for future OpenShift Container Platform releases.
2.2. FIPS support in components that the cluster uses
Although the OpenShift Container Platform cluster itself uses FIPS Validated / Modules in Process modules, ensure that the systems that support your OpenShift Container Platform cluster use FIPS Validated / Modules in Process modules for cryptography.
To ensure that the secrets that are stored in etcd use FIPS Validated / Modules in Process encryption, boot the node in FIPS mode. After you install the cluster in FIPS mode, you can encrypt the etcd data by using the FIPS-approved
aes cbc cryptographic algorithm.
For local storage, use RHEL-provided disk encryption or Container Native Storage that uses RHEL-provided disk encryption. By storing all data in volumes that use RHEL-provided disk encryption and enabling FIPS mode for your cluster, both data at rest and data in motion, or network data, are protected by FIPS Validated / Modules in Process encryption. You can configure your cluster to encrypt the root filesystem of each node, as described in Customizing nodes.
To ensure that containers know that they are running on a host that is using FIPS Validated / Modules in Process cryptography modules, use CRI-O to manage your runtimes. CRI-O supports FIPS-Mode, in that it configures the containers to know that they are running in FIPS mode.
2.3. Installing a cluster in FIPS mode
To install a cluster in FIPS mode, follow the instructions to install a customized cluster on your preferred infrastructure. Ensure that you set
fips: true in the
install-config.yaml file before you deploy your cluster.
AES CBC encryption to your etcd data store, follow the Encrypting etcd data process after you install your cluster.
If you add RHEL nodes to your cluster, ensure that you enable FIPS mode on the machines before their initial boot. See Adding RHEL compute machines to an OpenShift Container Platform cluster and Enabling FIPS Mode in the RHEL 7 documentation.