[xmlsec] Using a content ID for URI

[Johannes Kjos]

Hello!
I'm using xmlsec 0.0.15! And using an upgrade makes a lot of work for me
because other project participants have made quit a lot of work in the
0.0.15 code. 

My question is: Is it possible to make the xmlseclib to use a cid for URI in
SignedInfo References? E.g.I want the calling app to search through a some
blocks of a message, inside them there is cids to be resolved for the cids
in the references (the signature is in a header element). The calling app
should send e.g. filepath and URI to my secapp and I will make xmlsec to use
the file for digest but have the cid for that file in SignedInfo when
signing - and the other way when verifying.

Hope this is understandable...

Best regards,
Johannes