Authentication protocols that DO support hashed passwords

[E.S. Rosenberg]

On Mon, Nov 10, 2014 at 10:21 PM, Alan DeKok <aland at deployingradius.com> wrote:
> E.S. Rosenberg wrote:
>> No new EAP on the block that handles passwords stored in salted hashes?
>
>   Not really, no.  The reason is simple.
>
> Q: How do you get a new EAP method to 10^9 existing devices?
>
> A: You don't.
>
>> I understand that, my question is more "How is it that the various
>> RADIUS protocols can only work with cleartext passwords known on the
>> RADIUS server side?"
>
>   Because the RADIUS server gets given a hash by the client.  If the
> RADIUS server can find a clear-text password in the database, it can
> re-create the hash, and compare the two hashes.
>
>   If the RADIUS server has a hashed password in the database, it can't
> compare MD5(password) to SHA1(password).  The hashing methods are
> designed to make that kind of comparison *impossible*.
Since the hashing functions also exist on the client side what stops
the protocols from basing the hash requested from the client on the
_hash_ of the users' password?
And if it's salted then the server would have to send the salt used in
the db to the client so that it ends up with the same hash as the
server...
When you log into to an average modern *nix system it does exactly
that hash(password) compare to stored hash in /etc/shadow or ldap.
(And if salted first extract salt from stored hash then hash(salt,
password) and compare)

Regards,
Eli
>
>> To me (someone who has been doing systemadmin/network admin/(web)
>> development work) it seems like the most obvious thing in the world
>> that I don't want my users passwords to be stored anywhere where
>> me/any of my co-workers can get to them in cleartext and since root
>> can get everywhere that means cleartext passwords belong nowhere.
>
>   Your ideas are admirable, but unrealistic.
>
>> Now I may be naive or have never tried to develop an AUTH protocol, so
>> I am just very curious what the arguments are to store cleartext?
>
>   See above.
>
>   You *cannot* focus on one piece of the system.  "I want the passwords
> stored in hashed form in the DB, NO MATTER WHAT EFFECT IT HAS ANYWHERE
> ELSE IN THE NETWORK".
>
>   You have to take ALL things into consideration.  The supplicant (end
> user PC), database, authentication protocol, etc.  Then, choose the
> least crappy method which satisfies all pieces.
>
>   And the winner is usually clear-text passwords.
>
>   Alan DeKok.
> -
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