Adding Parameter to HTML Posted Form

SAML for ASP.NET
1

We are performing and IdP-initiated SSO connection using the SendSAMLResponseByHTTPPost to an SP of our client. Issue is that the SP is asking for a hidden parameter to be included in the HTML form that is posted. I’m not finding any documentation or examples of how to do this. Can someone tell me how this can be done (example below)?
HTTP Posted Form Currently is:
<html xmlns=“http://www.w3.org/1999/xhtml”>
<body onload=“document.forms.samlform.submit()”>


Note: Since your browser does not support JavaScript, you must press the Continue button once to proceed.



<form id=“samlform” action=“http://someurl” method=“post” target=“_self”>












What it needs to look like
<html xmlns=“http://www.w3.org/1999/xhtml”>
<body onload=“document.forms.samlform.submit()”>


Note: Since your browser does not support JavaScript, you must press the Continue button once to proceed.



<form id=“samlform” action=“http://someurl” method=“post” target=“_self”>













2

You can update the HTML form used for the HTTP Post using the HTTPPostBinding class under the ComponentSpace.SAML2.Bindings namespace.

The HTTPPostBinding.HTMLFormTemplate static property specifies the HTML form template to use.

The default is:

@“




Since your browser doesn’t support JavaScript, you must press the Continue button to proceed.



<form id=”“samlform”" action=“”{url}“” method=““post”” target=“”_self"“>

{hiddenFormVariables}



<input type=”“submit”" value=““Continue””/>






";

Make sure to preserve the {url} and {hiddenFormVariables} insertion parameters.