Request string not stored in SAML HTTP redirect binding

Question

We use Spring SAML Security Extension to implement SAML in our application. Now we have the following task:

One of our customers provides the URL of their identity provider, which contains the parameter. Metadata looks like this (abbreviated abbreviated):

<EntityDescriptor>
  <IDPSSODescriptor>
    <SingleSignOnService Binding="urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect"
        Location="https://idp.example.com/login?parameter=value"/>
  </IDPSSODescriptor>
</EntityDescriptor>

As you can see, there is a parameter called "parameter" with the value "value". This parameter is not in the generated redirect URL. I debugged a bit and found that I was SAMLProcessorImplgetting MessageEncoderfrom a binding (which is HTTPRedirectDeflateEncoderfor HTTP redirects) and delegates were encoding the message. The encoder, in turn, does the following in its method buildRedirectURL:

// endpointURL is https://idp.example.com/login?parameter=value here
URLBuilder urlBuilder = new URLBuilder(endpointURL);

List<Pair<String, String>> queryParams = urlBuilder.getQueryParams();
queryParams.clear(); // whoops

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?

Answer 1

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Answer 2

, HTTPRedirectDeflateEncoder, buildRedirectURL queryParams.clear(). URL- , SAML (, SigAlg ..), . Spring .

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