[Zope3-Users] Re: NTLM credential plugin

Gary Poster gary at zope.com
Wed Sep 13 09:29:22 EDT 2006

On Sep 13, 2006, at 2:30 AM, Philipp von Weitershausen wrote:

> Simon Hang wrote:
>> Hi,
>>  I'm thinging to write a NTLM credential plugin for zope3. But as  
>> I know, ntlm use 4-way handshake procedure, that means it needs  
>> two round-trips between server(zope3) and client(browser).
>>  When I look in the credential plugins, it has challenge mothed.  
>> But seems it is only design for 1 round-trip protocol. It can  
>> issue one challenge, and return to parent script.
> I don't see how the PAU only allows one "round-trip".

AIUI (I just looked up NTLM last night out of curiosity: see http:// 
www.innovation.ch/personal/ronald/ntlm.html), the problem is that the  
4 way handshake has to happen *within a single connection*.   
Apparently MS abuses HTTP to perform this.  Implementing it in  
pluggable auth made me scratch my head a bit, so I didn't reply.  You  
would need to slurp the request, then push back to the response, then  
slurp the same request again, then push back to the response, then  
slurp one more time, and finally reply with the real request.   
Describing the problem to Benji, he mentioned WSGI--that does seem  
like the only way I can imagine this working, and that would be  
tricky enough, especially if you needed to reach into Zope for the  
managed credentials.  Once the WSGI plugin did its magic, it would  
need to put something in the WSGI request that a pluggable auth  
plugin was willing to accept as authentication.

On the bright side, if you did this with WSGI you might be able to  
offer this as a generic Python WSGI NTLM tool that required only  
minimal integration with the back end app server.

I'm glad I'm not tasked with this. :-D  It sounds interesting,  
though.  Also, maybe I misunderstand: read the link if you want to  
come up with your own interpretation.


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