private Principal validateKerberosToken()

in services/idp-core/src/main/java/org/apache/cxf/fediz/service/idp/STSKrbAuthenticationProvider.java [158:206]
46 lines of code
10 McCabe index (conditional complexity)

    private Principal validateKerberosToken(
        KerberosServiceRequestToken token,
        IdpSTSClient sts
    ) {
        if (kerberosTokenValidator == null) {
            LOG.error("KerberosTokenValidator must be configured to support kerberos "
                + "credential delegation");
            return null;
        }

        final Principal kerberosPrincipal;
        try {
            KerberosServiceContext kerberosContext = kerberosTokenValidator.validate(token);
            if (kerberosContext == null || kerberosContext.getDelegationCredential() == null) {
                LOG.info("Kerberos Validation failure");
                return null;
            }
            GSSCredential delegatedCredential = kerberosContext.getDelegationCredential();
            sts.getProperties().put(SecurityConstants.DELEGATED_CREDENTIAL,
                                    delegatedCredential);
            sts.getProperties().put(SecurityConstants.KERBEROS_USE_CREDENTIAL_DELEGATION, "true");
            kerberosPrincipal = kerberosContext.getPrincipal();
        } catch (LoginException ex) {
            LOG.info("Failed to authenticate user", ex);
            return null;
        } catch (PrivilegedActionException ex) {
            LOG.info("Failed to authenticate user", ex);
            return null;
        }

        if (kerberosTokenValidator.getContextName() != null) {
            sts.getProperties().put(SecurityConstants.KERBEROS_JAAS_CONTEXT_NAME,
                                    kerberosTokenValidator.getContextName());
        }
        if (kerberosTokenValidator.getServiceName() != null) {
            sts.getProperties().put(SecurityConstants.KERBEROS_SPN,
                                    kerberosTokenValidator.getServiceName());
        }
        if (kerberosCallbackHandler != null) {
            sts.getProperties().put(SecurityConstants.CALLBACK_HANDLER,
                                    kerberosCallbackHandler);
        }
        if (kerberosUsernameServiceNameForm) {
            sts.getProperties().put(SecurityConstants.KERBEROS_IS_USERNAME_IN_SERVICENAME_FORM,
                                    "true");
        }

        return kerberosPrincipal;
    }