digital signature validation

Hello,

I have a couple of questions regarding the Security:Signature policy template. I included it in my policy and the goal was to validate the digital signature of the soap request. The first question is - why the parameters of the Signature Assertion template are read-only? (xpathPredicate, appendSignatureToSOAPHeader, placeSignatureInWSSecurityHeader, includeTimeStamp and addCertificateForSignature)? I have included the digital signature block in the soap request but I am getting error saying:

SOAP Fault :The signature verification failed (Cannot setup signature data structure)

So, I am not sure what else can I configure in the Signature assertion template (especially when the parameters are read-only).

The second question would be to know what format of the Digital Signature xml block is recommended so Infravio understands it and performs the validation.

The third question would be - how can one pass the Digital Signature block (or the whole SOAP header) to the Adapter Impl class? Or is there any other way of getting access to it from the custom Java code?

thanks
Arthur Markovsky