private JwsParts parseJws(final String jws) {
        LOGGER.debug("jws: {}", jws);

        try {
            // Step 1: Get the key id from JWT headers (the kid field)
            // Regex split on single char will not use regex so no need to pre-compile
            final String[] parts = jws.split("\\.");
            final String header = parts[0];
            final String payload = parts[1];
            final String signature = parts[2];

            LOGGER.debug("""
                    parseJws()
                    header: {}
                    payload: {}
                    signature: {}""", header, payload, signature);

            return new JwsParts(jws, header, payload, signature);
        } catch (Exception e) {
            LOGGER.debug("Unable to parse '{}' as a JWT", jws, e);
            throw new AuthenticationException(LogUtil.message(
                    "Error parsing token as a JSON Web Token: {}", e.getMessage()));
        }
    }
The user claims, in JSON web tokens (JWT) format.
stroom-security/stroom-security-common-impl/src/main/java/stroom/security/common/impl/StandardJwtContextFactory.java