FIPS 140-2 support

How to configure Keycloak server for FIPS compliance

The Federal Information Processing Standard Publication 140-2, (FIPS 140-2), is a U.S. government computer security standard used to approve cryptographic modules. Keycloak supports to run in FIPS 140-2 compliant mode. In this case, Keycloak will use only FIPS approved cryptography algorithms for it’s functionality.

To run in FIPS 140-2, Keycloak should run on a FIPS 140-2 enabled system. This requirement usually assumes RHEL or Fedora where FIPS was enabled during installation. See RHEL documentation for the details. When the system is in FIPS mode, it makes sure that the underlying OpenJDK is in FIPS mode as well and would use only FIPS enabled security providers.

BouncyCastle library

Keycloak internally uses the BouncyCastle library for many cryptography utilities. However, the default flavor of the BouncyCastle library that shipped with Keycloak is not FIPS compliant, but, BouncyCastle also provides a FIPS validated version of it’s library. The FIPS validated BouncyCastle library cannot be shipped with Keycloak due to license constraints and Keycloak cannot provide official support of it. Therefore, to run in FIPS compliant mode, you need to download BouncyCastle-FIPS bits and add them to the Keycloak distribution. When Keycloak executes in fips-mode, it will use the BCFIPS bits instead of the default BouncyCastle bits, which achieves FIPS compliance.

BouncyCastle FIPS bits

BouncyCastle FIPS can be downloaded from the BouncyCastle official page. Then you can add them to the directory KEYCLOAK_HOME/providers of your distribution. Make sure to use proper versions compatible with BouncyCastle Keycloak dependencies. The supported BCFIPS bits needed are:

  • bc-fips-

  • bctls-fips-1.0.14.jar

  • bcpkix-fips-1.0.7.jar

Generating keystore

You can create either pkcs12 or bcfks keystore to be used for the Keycloak server SSL. The pkcs12 works well in BCFIPS non-approved mode.

PKCS12 keystore can be generated with OpenJDK 17 Java on RHEL 9 in the standard way. Make sure that the system is in FIPS mode, you can check it with the following command:

fips-mode-setup --check

If the system is not in FIPS mode, you can enable it with the following command:

fips-mode-setup --enable

The command changes the default file in order to use FIPS enabled security providers, so no additional configuration is needed. Additionally, in PKCS12 keystore you can store PBE (password-based encryption) keys simply via the keytool command, which makes it ideal for using it with Keycloak KeyStore Vault and/or to store configuration properties in the KeyStore Config Source. For more details, see the Configuring Keycloak and the Using a vault.

BCFKS keystore generation requires the use of the BouncyCastle FIPS libraries and a custom security file.

You can start with create a helper file, such as /tmp/ The content of the file needs only to have the following property:


Next enter a command such as the following to generate the keystore:

keytool -keystore $KEYCLOAK_HOME/conf/server.keystore \
  -storetype bcfks \
  -providername BCFIPS \
  -providerclass org.bouncycastle.jcajce.provider.BouncyCastleFipsProvider \
  -provider org.bouncycastle.jcajce.provider.BouncyCastleFipsProvider \
  -providerpath $KEYCLOAK_HOME/providers/bc-fips-*.jar \
  -alias localhost \
  -genkeypair -sigalg SHA512withRSA -keyalg RSA -storepass passwordpassword \
  -dname CN=localhost -keypass passwordpassword \
Using self-signed certificates is for demonstration purposes only, so replace these certificates with proper certificates when you move to a production environment.

Similar options are needed when you are doing any other manipulation with keystore/truststore of bcfks type.

Running the server.

To run the server with BCFIPS in non-approved mode, enter the following command
bin/kc.[sh|bat] start --features=fips --hostname=localhost --https-key-store-password=passwordpassword --log-level=INFO,org.keycloak.common.crypto:TRACE,org.keycloak.crypto:TRACE
You can disable logging in production if everything works as expected.

Strict mode

There is the fips-mode option, which is automatically set to non-strict when the fips feature is enabled. This means to run BCFIPS in the "non-approved mode". The more secure alternative is to use --features=fips --fips-mode=strict in which case BouncyCastle FIPS will use "approved mode". Using that option results in stricter security requirements on cryptography and security algorithms.

When starting server, you can check that the startup log contains KC provider with the note about Approved Mode such as the following:

KC(BCFIPS version 1.000203 Approved Mode, FIPS-JVM: enabled) version 1.0 - class org.keycloak.crypto.fips.KeycloakFipsSecurityProvider,

Cryptography restrictions in strict mode

  • As mentioned in the previous section, strict mode may not work with pkcs12 keystore. It is needed to use another keystore (like bcfks) as mentioned earlier. Also jks and pkcs12 keystores are not supported in Keycloak when using strict mode. Some examples are importing or generating a keystore of an OIDC or SAML client in the Admin Console or for a java-keystore provider in the realm keys.

  • User passwords must be 14 characters or longer. Keycloak uses PBKDF2 based password encoding by default. BCFIPS approved mode requires passwords to be at least 112 bits (effectively 14 characters) with PBKDF2 algorithm. If you want to allow a shorter password, set the property max-padding-length of provider pbkdf2-sha256 of SPI password-hashing to value 14 to provide additional padding when verifying a hash created by this algorithm. This setting is also backwards compatible with previously stored passwords. For example, if the user’s database is in a non-FIPS environment and you have shorter passwords and you want to verify them now with Keycloak using BCFIPS in approved mode, the passwords should work. So effectively, you can use an option such as the following when starting the server:

Using the option above does not break FIPS compliance. However, note that longer passwords are good practice anyway. For example, passwords auto-generated by modern browsers match this requirement as they are longer than 14 characters.
  • RSA keys of 1024 bits do not work (2048 is the minimum). This applies for keys used by the Keycloak realm itself (Realm keys from the Keys tab in the admin console), but also client keys and IDP keys

  • HMAC SHA-XXX keys must be at least 112 bits (or 14 characters long). For example if you use OIDC clients with the client authentication Signed Jwt with Client Secret (or client-secret-jwt in the OIDC notation), then your client secrets should be at least 14 characters long. Note that for good security, it is recommended to use client secrets generated by Keycloak server, which always match this requirement.

Other restrictions

To have SAML working, make sure that a XMLDSig security provider is available in your security providers. To have Kerberos working, make sure that a SunJGSS security provider is available. In FIPS enabled RHEL 9 in OpenJDK 17.0.6, these security providers are not present in the, which means that they effectively cannot work.

To have SAML working, you can manually add the provider into JAVA_HOME/conf/security/ into the list fips providers. For example, add the line such as the following:


Adding this security provider should work well. In fact, it is FIPS compliant and likely will be added by default in the future OpenJDK 17 micro version. Details are in the bugzilla.

It is recommended to look at JAVA_HOME/conf/security/ and check all configured providers here and make sure that the number matches. In other words, fips.provider.7 assumes that there are already 6 providers configured with prefix like fips.provider.N in this file.

If prefer not to edit your file inside java itself, you can create a custom java security file (for example named and add only the single property above for adding XMLDSig provider into that file. Then start your Keycloak server with this property file attached:

For Kerberos/SPNEGO, the security provider SunJGSS is not yet fully FIPS compliant. Hence it is not recommended to add it to your list of security providers if you want to be FIPS compliant. The KERBEROS feature is disabled by default in Keycloak when it is executed on FIPS platform and when security provider is not available. Details are in the bugzilla.

Run the CLI on the FIPS host

If you want to run Client Registration CLI (|bat script) or Admin CLI (|bat script), the CLI must also use the BouncyCastle FIPS dependencies instead of plain BouncyCastle dependencies. To achieve this, you may copy the jars to the CLI library folder and that is enough. CLI tool will automatically use BCFIPS dependencies instead of plain BC when it detects that corresponding BCFIPS jars are present (see above for the versions used). For example, use command such as the following before running the CLI:

cp $KEYCLOAK_HOME/providers/bc-fips-*.jar $KEYCLOAK_HOME/bin/client/lib/
cp $KEYCLOAK_HOME/providers/bctls-fips-*.jar $KEYCLOAK_HOME/bin/client/lib/
When trying to use BCFKS truststore/keystore with CLI, you may see issues due this truststore is not the default java keystore type. It can be good to specify it as default in java security properties. For example run this command on unix based systems before doing any operation with kcadm|kcreg clients:
echo "keystore.type=bcfks
fips.keystore.type=bcfks" > /tmp/
export KC_OPTS=""

Keycloak server in FIPS mode in the container

When you want Keycloak in FIPS mode to be executed inside a container, your "host" must be using FIPS mode as well. The container will then "inherit" FIPS mode from the parent host. See this section in the RHEL documentation for the details.

The keycloak container image will be just automatically in fips mode when executed from the host in FIPS mode. However, make sure that the Keycloak container also uses BCFIPS jars (instead of BC jars) and proper options when started.

Regarding this, it is best to build your own container image as described in the Running Keycloak in a container and tweak it to use BCFIPS etc.

For example in the current directory, you can create sub-directory files and add:

  • BC FIPS jar files as described above

  • Custom keystore file - named for example keycloak-fips.keystore.bcfks

  • Security file with added provider for SAML

Then create Dockerfile in the current directory similar to this:

FROM as builder

ADD files /tmp/files/

WORKDIR /opt/keycloak
RUN cp /tmp/files/*.jar /opt/keycloak/providers/
RUN cp /tmp/files/keycloak-fips.keystore.* /opt/keycloak/conf/server.keystore
RUN cp /tmp/files/ /opt/keycloak/conf/

RUN /opt/keycloak/bin/ build --features=fips --fips-mode=strict

COPY --from=builder /opt/keycloak/ /opt/keycloak/

ENTRYPOINT ["/opt/keycloak/bin/"]

Then build FIPS an optimized docker image and start it as described in the Running Keycloak in a container. These steps require that you use arguments as described above when starting the image.

Migration from non-fips environment

If you previously used Keycloak in the non-fips environment, it is possible to migrate it to FIPS environment including it’s data. However, restrictions and considerations exist as mentioned in previous sections. To highlight some of them:

  • Make sure all the Keycloak functionality relying on keystores uses only supported keystore types. This differs based on whether strict or non-strict mode is used.

  • Kerberos authentication may not work. If your authentication flow uses Kerberos authenticator, this authenticator will be automatically switched to DISABLED when migrated to FIPS environment. It is recommended to remove any Kerberos user storage providers from your realm and disable Kerberos related functionality in LDAP providers before switching to FIPS environment.

In addition to the preceding requirements, be sure to doublecheck this before switching to FIPS strict mode:

  • Make sure that all the Keycloak functionality relying on keys (for example, realm or client keys) use RSA keys of at least 2048 bits

  • Make sure that clients relying on Signed JWT with Client Secret use at least 14 characters long secrets (ideally generated secrets)

  • Password length restriction as described earlier. In case your users have shorter passwords, be sure to start the server with the max padding length set to 14 of PBKDF2 provider as mentioned earlier. If you prefer to avoid this option, you can for instance ask all your users to reset their password (for example by the Forget password link) during the first authentication in the new environment.

Keycloak FIPS mode on the non-fips system

Keycloak is tested on a FIPS enabled RHEL 8 system and ubi8 image. It is supported with RHEL 9 (and ubi9 image) as well. Running on the non-RHEL compatible platform or on the non-FIPS enabled platform, the FIPS compliance cannot be strictly guaranteed and cannot be officially supported.

If you are still restricted to run Keycloak on such a system, you can at least update your security providers configured in file. This update does not mean FIPS compliance, but at least the setup is closer to it. It can be done by providing a custom security file with only an overriden list of security providers as described earlier. For a list of recommended providers, see the OpenJDK 17 documentation.

You can check the Keycloak server log at startup to see if the correct security providers are used. TRACE logging should be enabled for crypto-related Keycloak packages as described in the Keycloak startup command earlier.

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