All the steps below were tested on RHEL 8.6 with FIPS mode enabled (See [this page](https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/security_hardening/assembly_installing-a-rhel-8-system-with-fips-mode-enabled_security-hardening#doc-wrapper)
for the details) and with OpenJDK 17.0.5 on that host.
Also make sure to set `KEYCLOAK_SOURCES` to the location with your Keycloak codebase.
Note that for keystore generation, it is needed to use the BouncyCastle FIPS libraries and use custom security file, which
will remove default SUN and SunPKCS11 providers as it doesn't work to create keystore with them on FIPS enabled OpenJDK11 due
the limitation described here https://access.redhat.com/solutions/6954451 and in the related bugzilla https://bugzilla.redhat.com/show_bug.cgi?id=2048582.
4) For the `fips-mode` option, the more secure alternative is to use `--fips-mode=strict` in which case BouncyCastle FIPS will use "approved mode",
which means even stricter security requirements on cryptography and security algorithms. Few more points:
- As mentioned above, strict mode won't work with `pkcs12` keystore. So it is needed to use other keystore (probably `bcfks`).
- 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). If you want to allow shorter password, you need to set property `max-padding-length` of
provider `pbkdf2-sha256` of SPI `password-hashing` to value 14, so there will be some additional padding used when verifying hash created by this algorithm.
This is also backwards compatible with previously stored passwords (if you had your user's DB in non-FIPS environment and you have shorter passwords and you
want to verify them now with Keycloak using BCFIPS in approved mode, it should work fine). So effectively, you can use option like this when starting the server:
- RSA keys of 1024 bits don't work (2048 is the minimum). This applies for keys used by Keycloak realm itself (Realm keys from the `Keys` tab), 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` (aka `client-secret-jwt`), then your client secrets should be at least 14 characters long.
But anyway, it is recommended to use client secrets generated by Keycloak server, which always matches this requirement.
When starting server at startup, you can check that startup log contains `KC` provider contains KC provider with the note about `Approved Mode` like this:
For Kerberos, there are few more things to be done to have security provider FIPS compliant. Hence it is not recommended to add security provider
if you want to be FIPS compliant. The `KERBEROS` feature is disabled by default in Keycloak when it is executed on this platform and when security provider is not
