private Optional<HeaderToken> getTokenFromHeader(final HttpServletRequest request) {
        // When using an AWS ELB/ALB that is integrated with the IDP, the ELB/ALB will
        // do the auth flow and just pass us a different header containing the claims obtained
        // from the IDP. See
        // https://docs.aws.amazon.com/elasticloadbalancing/latest/application/listener-authenticate-users.html
        // We may be dealing with requests of either form
        if (LOGGER.isDebugEnabled()) {
            // This will log the AWS identity if there is one
            JwtUtil.getJwsFromHeader(request, AMZN_OIDC_IDENTITY_HEADER);
        }
        return JwtUtil.getJwsFromHeader(request, AMZN_OIDC_DATA_HEADER)
                .map(jws -> new HeaderToken(AMZN_OIDC_DATA_HEADER, jws))
                .or(() ->
                        JwtUtil.getJwsFromHeader(request, AUTHORIZATION_HEADER)
                                .map(jws -> new HeaderToken(AUTHORIZATION_HEADER, jws)));
    }
The user claims, in JSON web tokens (JWT) format.
stroom-security/stroom-security-common-impl/src/main/java/stroom/security/common/impl/StandardJwtContextFactory.java