OpenSAML user discussion

[John Gonzales <>]

Hi there,

I am sending an encoded message across the wire to a Rails application I am
developing. When I try decode this message, I get the an error of
"Zlib::DataError incorrect header check". I have tried many different things
not the Rails-end of this equation, but I'm wondering if there might be
something wrong on the OpenSAML-end via the Java OpenSAML Library.

Here is my Java code that encodes the message:

                HttpServletResponseAdapter responseAdapter = new
HttpServletResponseAdapter(response, false);
               
responseAdapter.setStatusCode(HttpServletResponse.SC_MOVED_TEMPORARILY);
                
                SingleSignOnService ssoService = new
SingleSignOnServiceBuilder().buildObject();
                ssoService.setLocation(identityProviderSSOServiceURL);
                
                AuthnRequest authnRequest = Saml2Util.createAuthnRequest();
                BasicSAMLMessageContext messageContext = new
BasicSAMLMessageContext();
                messageContext.setOutboundMessage(authnRequest);
                messageContext.setOutboundSAMLMessage(authnRequest);
                messageContext.setOutboundMessageTransport(responseAdapter);
                messageContext.setPeerEntityEndpoint(ssoService);
                
                HTTPRedirectDeflateEncoder encoder = new
HTTPRedirectDeflateEncoder();
                encoder.encode(messageContext);

On the Rails-end, all GET parameters are automatically URL-decoded. So all I
need to do is Base64 Decode, then INFLATE. Here is my code that does this
latter piece:

                Zlib::Inflate.inflate(Base64.decode64(message)

message is the URL-decoded SAMLRequest GET parameter.

Fairly simple, but then again, I'm not sure if I implemented the Java-end
correctly. In any case, when my Ruby/Rails code executes, I get the error I
mentioned above. For good measure, here it is once again:

                Zlib::DataError (incorrect header check):
                  mylib/codecs.rb:19:in `inflate'

As the stack trace reports, the error is happening while trying to inflate the
message. I've searched and tried many alternatives to get this message to
decode on the Rails-end, but nothing has worked so far. My searches are
suggesting that perhaps the message itself is corrupt, which is why I'm taking
a look at the Java-end.

I've been scratching my head for the two-hours on the Rails-end, and the past
hour on the Java-end. Needless to say, any help would be greatly appreciated!

Thanks in advance!