On Sun, Apr 20, 2008 at 2:36 AM, Michael B Allen <[EMAIL PROTECTED]> wrote:

> On Sat, Apr 19, 2008 at 6:24 PM, Isaak Malik <[EMAIL PROTECTED]> wrote:
> >  'What exact attack scenario is this "static [salt] which is located
> >  outside of your web root" supposed to protect against?'
> >
> > This will increase the difficulty of cracking your hashes with brute
> force
> > when the hacker has access to your database, by only using the salt
> stored
> > in the database it will be the same for the hacker as if no salt was
> used to
> > hash the password.
>
> I don't even understand this statement so it's hard to comment. But I
> have a feeling that you don't understand how the hashing methods we're
> talking about actually work.


It's possible that I'm going a bit off-topic as I didn't read every email on
this subject. But to explain what I'm talking about: let's say for example
the attacker has a dictionary containing the following:
password
password123
passw0rd
p4ssw0rd
Password

If the webmaster makes use of randomly generated salts the attacker would
have more trouble cracking since the cracking software probably won't find
duplicate hashes in the database.

I guess that what you are talking about is that the attacker generates
different wordlists for every salt before starting the attack, what I'm
talking about is that the attacker is "smart" enough to use or create a
software that automatically prepends and/or appends the salt to the word
from the list if given and then compared to the password hash from the
database.

Let's say that the attacker found the login details for the database, which
you probably think is very unlikely since you find the static salt useless.
I'll mention a common example:
---
The webmaster stores the database connection details in database.inc and
loads the details via the ZFW Config class then connects to the database,
the clever or lucky attacker found the database.inc file and is able to see
its contents because the webserver displays it as plain text by default.
This far the attacker wins the battle.
---

Note: The above example is not necessarily put in practice because the
webmaster uses the ZFW, I'm just pointing out a very common way of storing
important data in a very insecure way and put it in context with the ZFW
since we are discussing this subject on their mailing list.

Since we now both agree (at least I hope so) that this can happen the static
salt would be an extra layer of protection since the attacker either doesn't
know about it or doesn't have access to it so his wordlist wouldn't be much
help. This time the webmaster wins the battle.


>
> > "Have you read it? You have to calculate an individual dictionary for
> >  every password."
> >
> > Yes I did read it, even if a password has been cracked it won't be much
> > trouble for the hacker to crack a duplicate even if it has another salt,
> > unless we're talking about a dictionary containing millions of words.
>
> Ahh, yes, you definitely don't understand how these hashing methods work.
>
> A password salt is a randomly generated value that is computed anew
> every time someone sets their password. Even if the same user sets the
> same password twice the salt and thus the hash will be totally
> different every time. To crack one single password the attacker would
> have to compute a dictionary of passwords with that specific salt just
> to crack that one password. That's not likely. An additional "static
> salt" does not help unless the attacker has the password database but
> not the "static salt" which is also not very likely.
>  <http://www.ioplex.com/>
>

That was exact the same thing I said.. Except for that you take it into
context when the attacker generates a dictionary of passwords combined with
the salt before commencing the attack, I'm talking about, which I also
mentioned above, that the attacker creates the hashes live and then
comparing to the hashes, perhaps this is a method less used by professional
crackers since this requires more CPU resources but it is certainly
possible.

This should explain why the static salt would be of use.

-- 
Isaak Malik
Web Developer

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