private boolean isRemoteHostTrustedCertProvider(final ServletRequest request,
                                                    final ReceiveDataConfig receiveDataConfig) {
        final Set<String> allowedCertificateProviders = receiveDataConfig.getAllowedCertificateProviders();
        if (NullSafe.hasItems(allowedCertificateProviders)) {
            final String remoteHost = request.getRemoteHost();

            boolean isTrusted = false;
            if (NullSafe.isNonBlankString(remoteHost)) {
                isTrusted = allowedCertificateProviders.contains(remoteHost);
            }
            if (!isTrusted) {
                final String remoteAddr = request.getRemoteAddr();
                if (NullSafe.isNonBlankString(remoteAddr)) {
                    isTrusted = allowedCertificateProviders.contains(remoteAddr);
                }
            }
            LOGGER.debug("isTrusted: {}, remoteHost: {}, remoteAddr: {}, allowedCertificateProviders: {}",
                    isTrusted, request.getRemoteHost(), request.getRemoteAddr(), allowedCertificateProviders);
            return isTrusted;
        } else {
            return true;
        }
    }
Pull out the Subject from the certificate. E.g.
"CN=some.server.co.uk, OU=servers, O=some organisation, C=GB"
stroom-receive/stroom-receive-common/src/main/java/stroom/receive/common/CertificateExtractorImpl.java