RE: Can you impersonate a client side cert??

["Michael Howard" <mikehow () microsoft com>]

Depends on a number of things. For example, IIS4 and IIS5 natively
support this, the IIS5 version is better as it can tie into Active
Directory, which, by default will use the CN in the cert as the
principal to use. You can also add alternate names in AD to map onto the
same principal.

Note that if you use CertSrv in enterprise mode, where the cert is
already part of the user's entry, there is nothing you need to do -
everything happens for you!

The same stuff holds true for smartcard login in Win2000 and later...

This is why schannel is integrated into lsa in win2000 and later...

Of course, the server must trust the cert issuer, and all other validity
checks must pass (date validity, not revoked etc)

Cheers, MH
Secure Windows Inititative
Got an access denied? Good, my job is done!
Writing Secure Code: http://www.microsoft.com/mspress/books/5612.asp


-----Original Message-----
From: Darren Craig [mailto:darren.craig () celare co uk] 
Sent: Monday, January 28, 2002 4:00 AM
To: pen-test () securityfocus com
Subject: Can you impersonate a client side cert??


Hi All,


I have been reading a paper which was published back in Feb 2001 by a
company call Sensepost which says that there is a way to impersonate a
users
client side cert by using the same common name. Does anybody have any
experience of doing this or is it even possible considering that the
users
public part of the cert would be installed on the web server?

Darren


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