Re: [wss-comment] Password Digest

[Pete Wenzel <pete@seebeyond.com>]

Correct.  This is known as "plaintext equivalence" in the literature.
In your case #2, an attacker need not have the actual password;
obtaining the hash of the password will allow spoofing ability
equivalent to the intended user.  This is often the case in simple
shared-secret schemes like this, and the reason that other
technologies like one-time passwords, public key crypto and SRP (see
RFC 2945) are used when the authentication database is at risk of
being compromised.

--Pete
Pete Wenzel <pete@seebeyond.com>
Senior Architect, SeeBeyond
Standards & Product Strategy
+1-626-471-6311 (US-Pacific)

Thus spoke Ronald van Kuijk (rvkuijk@abz.nl) on Tue, Oct 07, 2003 at 01:20:01AM +0200:
> I'm no real security expert but as you describe it, aren't the security
> risks the same with both?
> 1.  Base64(SHA-1(nonce + created + password))
> 2.  Base64(SHA-1(nonce + created + SHA-1(password)))  
> In case 1 you store it cleartext on the server and and use it cleartext
> on the client side
> In case 2 you store it sha-1 on the server and use it sha-1 on the
> client side
> 
> In both cases you could steal the content of e.g. the ldap server and
> get into the system. The issue, imho, IS what is send over the network
> and not (mainly) what is stored. You own the machine it is stored on (in
> most cases) you do not however own the network.
> 
> Ronald
> 
> > -----Oorspronkelijk bericht-----
> > Van: eclogue chang [mailto:e1bridge@yahoo.com]
> > Verzonden: dinsdag 7 oktober 2003 0:24
> > Aan: wss-comment@lists.oasis-open.org
> > Onderwerp: [wss-comment] Password Digest 
> > 
> > 
> > UsernameToken Profile, working draft 4, 11/08/2003,  
> > Line 106-108 talks about digested password offers no
> > additional security. Did I miss something here? The
> > issue is not what is sent over the network; instead it
> > is how the services side compares the password. If the
> > clear text password is used, then the Services
> > Provider has to store the clear text password for
> > password validation. This is a security issue. 
> > 
> > Also, Line 119 Password_Digest = Base64(SHA-1(nonce +
> > created + password))  has the same problem. In this
> > case, the Service Provider unable to store hashed
> > password, instead it has to store the clear text
> > password in its database. This will create a big
> > security issue. 
> > 
> > If the password digest change to the follow, then this
> > issue goes away.  
> > 
> > Password_Digest = Base64(SHA-1(nonce + created +
> > SHA-1(password)))  
> > 
> > Can this suggestion be considered? 
> > 
> > 
> > Eclouge  Chang