Image Overview: keycloak-fips

Overview: keycloak-fips Chainguard Image


A wolfi-based image tailored for Keycloak, incorporating the required bouncycastle FIPS modules (bcfips) to facilitate Keycloak’s operation in FIPS mode.

Both OpenJDK and Keycloak have been configured to harness the BouncyCastle FIPS API at their core. The included bcfips module meets FIPS 140-2 compliance requirements and is accredited under: FIPS certificate 4616.


This image is equipped with the essential components for Keycloak to operate in FIPS mode. However, it’s important for users to ensure they use it in line with FIPS compliance standards.

This includes tasks such as keystore generation, configuration, and launching Keycloak with the correct configuration parameters. More guidance is provided in the sections below.


Keycloak requires a bcfips-compatible keystore to manage its SSL/TLS certificates.

Although Keycloak supports various keystore types, only BCKFS offers the capability to operate in approved (strict) mode under FIPS standards, ensuring only approved ciphers are used.

BCKFS Keystore creation

Refer to the official documentation for information on how to create and configure a Keystore.

Note: The keystore needs to be generated on a seperate image, as the keytool application will not operate when bcfips is running in approved mode. Here is a snippet from our communication with the BouncyCastle maintainers:

keytool will not run if bcfips is running in approved mode. It is hard coded to pass a new SecureRandom(), which will always fail the approved RNG test.

Below is an example, using a wolfi-base container to generate a bckfs keystore:

docker run -v $(pwd):/tmp/keystore -it sh

apk update && apk add curl openjdk-17-default-jvm

# Refer to Keycloak docs: 'BCFKS keystore' section for context.
echo "securerandom.strongAlgorithms=PKCS11:SunPKCS11-NSS-FIPS" >

# for latest `bc-fips` version
curl<VERSION>.jar \
-o bc-fips.jar

keytool -v -keystore /tmp/keystore/server.keystore \
  -J--add-exports=java.base/ \
  -storetype bcfks \
  -providername BCFIPS \
  -providerclass org.bouncycastle.jcajce.provider.BouncyCastleFipsProvider \
  -providerpath bc-fips.jar \
  -alias localhost \
  -genkeypair -sigalg SHA512withRSA -keyalg RSA \
  -dname CN=localhost \

Run image

This image aligns with the original upstream image regarding its entrypoint and command-line arguments. Also see the Keycloak GitHub repository, and the KeyCloak FIPS documentation.

Running in development mode

Example of launching Keycloak in development mode, with HTTP enabled and strict hostname resolution not enforced:

docker run -v $(pwd)/server.keystore:/usr/share/java/keycloak/conf/server.keystore \
  --rm --name local-Keycloak -p 8080:8080 \
  -e KEYCLOAK_ADMIN=admin \
    <YOUR-REGISTRY>/keycloak-fips:latest \
    start-dev \
      --features=fips \
      --fips-mode=strict \
      --https-key-store-password='<KEYSTORE-PASSWORD>' \
      --hostname=localhost \

In this example, the Keycloak UI is accessible via: http://localhost:8080.

Running in production mode

Example of running Keycloak in production mode, enforcing the use of HTTPS and requiring a hostname to be provided:

docker run -v /local/path/to/server.keystore:/usr/share/java/keycloak/conf/server.keystore \
  --rm --name local-Keycloak -p 8443:8443 \
  -e KEYCLOAK_ADMIN=admin \
  	start \
      --features=fips \
      --fips-mode=strict \
      --https-key-store-password='<KEYSTORE-PASSWORD>' \
      --hostname=localhost \

In this example, the Keycloak UI is accessible via: https://localhost:8443.

FIPS validation

You’ll see debug logs such as the below if Keycloak is running in FIPS mode:

KC(BCFIPS version 1.000204 Approved Mode) version 1.0 - class org.Keycloak.crypto.fips.KeycloakFipsSecurityProvider,
 BCFIPS version 1.000204 - class org.bouncycastle.jcajce.provider.BouncyCastleFipsProvider

Additionally, you can check bcfips is enforcing minimum password lengths, by running the container with a non-compliant admin password, such as 1234:

Caused by: org.bouncycastle.crypto.fips.FipsUnapprovedOperationError:
password must be at least 112 bits

Customizing the image

Keycloak provides a mechanism to configure and customize the image. This process is outlined in the Keycloak image documentation.

There are subtle differences in the executable paths used in the Chainguard image. Below is the example copied from the documentation, updated with the correct paths:

FROM as builder

# Enable health and metrics support

# Configure a database vendor
ENV KC_DB=postgres

WORKDIR /usr/share/java/Keycloak

# for demonstration purposes only, please make sure to use proper certificates in production instead
RUN keytool -genkeypair -storepass password -storetype PKCS12 -keyalg RSA -keysize 2048 -dname "CN=server" -alias server -ext "SAN:c=DNS:localhost,IP:" -keystore conf/server.keystore
RUN /usr/share/java/Keycloak/bin/ build

COPY --from=builder /usr/share/java/Keycloak/ /usr/share/java/Keycloak/

# change these values to point to a running postgres instance
ENV KC_DB=postgres
ENTRYPOINT ["/usr/share/java/Keycloak/bin/"]


Invalid Keystore Format with BCFKS in production mode

Error Message:

# start --features=fips --hostname=localhost --https-key-store-password='**********'
ERROR: Failed to start server in (production) mode
ERROR: Unable to start HTTP server
ERROR: Invalid keystore format

Solution: BCFKS Keystores default to strict mode, and it’s likely you omitted --fips-mode=strict in your arguments. If you wish to run in non-strict mode with BCFKS, you need to include --https-key-store-type=bcfks.

This is called out in the official documentation, but perhaps could benefit from additional clarification.

Keystore corrupted error upon launch

Error Message:

ERROR: Unable to start HTTP server
ERROR: BCFKS KeyStore corrupted: MAC calculation failed.
ERROR: BCFKS KeyStore corrupted: MAC calculation failed.

Solution: The error indicates that a Keystore was detected, but there was an issue parsing it. Usually this means that the password used to create the keystore does not match what was provided as the --https-key-store-password argument to Keycloak.

Key material not provided error in production mode

Error Message:

ERROR: Failed to start server in (production) mode
ERROR: Key material not provided to setup HTTPS. Please configure your
keys/certificates or start the server in development mode.

Solution: This error usually indicates that a .keystore was not detected in the /usr/share/java/keycloak/conf directory. Ensure you have created a Keystore and it is accessible to the container in the expected directory.

Password must be at least 112 bits

Error Message:

Failed to add user '<admin-user>' to realm 'master': org.keycloak.models.ModelException:
password must be at least 112 bits
FipsUnapprovedOperationError: password must be at least 112 bits

Solution: This is expected whenever Keycloak is running in strict (approved) mode for FIPS. Choose a longer admin password which is compliant. Refer to the Keycloak FIPS documentation for more information.

Last updated: 2024-02-29 16:25