Posting data through shibboleth

[Cantor, Scott]

> My bad for not specifying, we're on IIS. Found this:
> xmltooling::IOException: The request's Content-Length is not
> available to an ISAPI filter.

Good job finding that. I should have asked about the web server.

Unfortunately, the old ISAPI filter is long unsupported. The modern SP version provides a module that's built for IIS 7 and up. Basically somebody let that deployment rot and hasn't kept it up to date.

The old filter doesn't support POST handling, it was an Apache feature only at that time, IIS filters don't have access to the request body.

I believe the newer module does support that feature in theory at least. 

-- Scott