OPIE considered insecure

[Alexander Leidinger]

Quoting Benjamin Lutz <mail at maxlor.com> (from Wed, 11 Feb 2009  
18:21:53 +0100):

> Hello,
>
> I've been thinking about what to do about OPIE, and I see the following
> possibilities. (Note: this is mainly just a braindump to collect my
> thoughts; many details that seem obvious to me are omitted. I'm making it
> public because others might be interested in it too.)
[...]
> - Implement another algorithm: OTPW
[...]

- Implement something which is similar o freeauth.org, just better  
implemented and without the "not so good" stuff / design decissions.

Short: they need something you know (PIN) + something you have (e.g.  
token, or mobile phone with java with some fixed key). You then enter  
your arbitrary long PIN into the phone, and it will give you a time  
limited key to login (so the time needs to be in sync to some extend).  
On the machine you login you need the cleartext version of your PIN,  
the fixed key, and ideally it saves the the PW you just used to login  
to prevent a relogin with the same PW. If you've seen the remote login  
tokens from RSA or similar, then you should get the idea what this is  
about.

I wrote down a while ago the algorithm somewhere (based upon my own  
thoughts how to do it, this was before I've seen freeauth, so it's  
independent), and also thought about the bells and whistles (some  
security pitfalls you need to think about). If you are interested in  
implementing this (ideally with a BSD license for inclusion into the  
base system)

-- 
Oh, yeah, life goes on, long after the thrill of livin' is gone.
		-- John Cougar, "Jack and Diane"

http://www.Leidinger.net    Alexander @ Leidinger.net: PGP ID = B0063FE7
http://www.FreeBSD.org       netchild @ FreeBSD.org  : PGP ID = 72077137