help with error processing SAML request to IdP

[Peter Schober]

* IAM David Bantz <db at alaska.edu> [2016-09-29 14:55]:
> Here's the SAML request as presented in Firefox SAML Tracer:

That representation is probably useless to debug problems with actual
on-the-wire protocol messages.

> and the error in Shib IdP process log:
> 
> 04:36:39.849 - ERROR
> [org.opensaml.ws.message.decoder.BaseMessageDecoder:208] - Encountered
> error parsing message into its DOM representation
> > org.opensaml.xml.parse.XMLParserException: Unable to read XML from input stream
> >
> >         at org.opensaml.xml.parse.StaticBasicParserPool.parse(StaticBasicParserPool.java:237) ~[xmltooling-1.4.0.jar:na]
> > ...
> >
> > Caused by: java.util.zip.ZipException: oversubscribed dynamic bit lengths tree

I'm not familiar with that error and you're not really providing
sufficient co(n)text, but how/where did your IDP recieve the authn
request?
If there were a mismatch (e.g. POST to your Redirect endpoint) I guess
the IDP would have failed (and complained) differently but it might
still be instructive to know the specifics.
-peter