WCF: CustomBinding confuses endpoint

Question

Hi!

I am using CustomBinding to enable Soap 1.1 (endpoint does not support 1.2) + Addressing 1.0. The endpoint is only available over SSL, and runs on some kind of Java/Weblogic platform.

Here is my configuration:

<customBinding>
    <binding name="Soap11Addr10">
        <textMessageEncoding messageVersion="Soap11WSAddressing10" />
        <httpsTransport/>
    </binding>
</customBinding>

[...]

<endpoint address="https://sekrit:444/more-sekrits/even-more"
    binding="customBinding" bindingConfiguration="Soap11Addr10"
    contract="SomePort" name="SomePortService" />

This configuration seems to confuse the endpoint. When I perform a request against SomePort, WCF first sends a RequestSecurityTokenResponse message, which I think may be unfortunate. Here is a trace of the RSTR envelope:

<s:Envelope xmlns:a="http://www.w3.org/2005/08/addressing" xmlns:s="http://www.w3.org/2003/05/soap-envelope"&gt;
  <s:Header>
    <a:Action s:mustUnderstand="1">http://schemas.xmlsoap.org/ws/2005/02/trust/RSTR/Issue&lt;/a:Action&gt;
    <a:RelatesTo>urn:uuid:7348d908-b767-43e8-9770-09a38461ee87</a:RelatesTo>
  </s:Header>
  <s:Body>
    <t:RequestSecurityTokenResponse Context="uuid-7a3c9fde-053d-46e7-aa08-f5725b082691-287" xmlns:t="http://schemas.xmlsoap.org/ws/2005/02/trust" xmlns:u="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd"&gt;
      <t:BinaryExchange ValueType="http://schemas.xmlsoap.org/ws/2005/02/trust/spnego" EncodingType="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-soap-message-security-1.0#Base64Binary"&gt;TlRMTVNTUAACAAAAEAAQADgAAAA1wpriPjzjL4iwIJhAmcsBAAAAAGAAYABIAAAABgByFwAAAA9TAEsATwBHAEsAQQBUAFQAAgAQAFMASwBPAEcASwBBAFQAVAABABAAUwBLAE8ARwBLAEEAVABUAAQAEABTAGsAbwBnAGsAYQB0AHQAAwAQAFMAawBvAGcAawBhAHQAdAAHAAgAj73D884kywEAAAAA&lt;/t:BinaryExchange&gt;
    </t:RequestSecurityTokenResponse>
  </s:Body>
</s:Envelope>

The endpoint barfs:

<env:Envelope xmlns:env="http://schemas.xmlsoap.org/soap/envelope/"&gt;
  <env:Header></env:Header>
  <env:Body>
    <env:Fault xmlns:ns0="http://schemas.xmlsoap.org/soap/envelope/"&gt;
      <faultcode xmlns="">ns0:MustUnderstand</faultcode>
      <faultstring xml:lang="en" xmlns="">One or more mandatory SOAP header blocks not understood</faultstring>
    </env:Fault>
  </env:Body>
</env:Envelope>

Is it possible to stop the initial RSTR from being sent?

I can provide more trace and log data upon request.