I think I have discovered the issue but do not know how to resolve. If I post locally and insecurely to http://xsbrt2.heliohost.org, it works and I can write files via a web application. If I post to https://xsbrt2.heliohost.org, it fails because the SSL certificate is issued for lily.heliohost.org, not xsbrt2.heliohost.org. Thoughts on how I can read/write securely?