RE: [saml-dev] (ex / non ex) canonical XML

From
Cahill, Conor P <>
Date
2006-03-14T14:16:48+00:00
ID
8AEB79DC01BE994D8DE3FD02FA5B475B03069B57@orsmsx409
Thread
RE: [saml-dev] (ex / non ex) canonical XML
I think many early implementations worked without the need 
for signatures (e.g. artifiact across browser and unsigned assertion on trusted 
back channel).

 

Conor

  

  
  From: Brian Campbell 
  [mailto:] 
Sent: Tuesday, March 14, 2006 
  9:15 AM
To: 
Subject: 
  [saml-dev] (ex / non ex) canonical XML

  

  

  
All,

  
 

  
Forces beyond my control have 
  taken me on a little trip back in time to look at SAML 1.0 (I didn’t get 
  involved in this space until after SAML 1.1 was out so this has been an 
  interesting learning experience for me).   I see that one of the 
  major differences between dot zero and dot one is changing the recommended 
  c14n method from canonical XML 
  (http://www.w3.org/TR/2001/REC-xml-c14n-20010315) to exclusive canonical XML 
  (http://www.w3.org/2001/10/xml-exc-c14n#).  I can 
  see why this change was made and, although I’ve not yet had the pleasure, I 
  can imagine that there were some interoperability problems when trying to use 
  the non-exclusive transform.  My question is - how did SAML 1.0 
  implementations deal with this?  Were they only able to interoperate when 
  signatures where applied to the response in the post profile?  What is 
  the value of a signed assertion if the signature cannot be verified 
  independent of its original document context (I guess there isn’t one and 
  that’s why 1.1 made the change but did implementations try to work around it 
  somehow)?  Did implementers end up just using exclusive in spite of the 
  spec recommendation?  

  
 

  
I would appreciate any historical 
  perspective that can be provided by those of you that have been involved with 
  stuff longer than I.

  
 

  
Thanks,

  
Brian

  
 

  
By the way, the 
  sstc-saml-diff-1.1-draft-01 
  document has proven to be a very informative resource - I’d like to say thanks 
  to Prateek, Dipak, Jahan and Robert.