john-users - How does it actually dictionary attack salted hashes?

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Date: Mon, 29 May 2006 16:58:06 -0400
From: "John Paine" <guipenguin@...il.com>
To: john-users@...ts.openwall.com
Subject: How does it actually dictionary attack salted hashes?

If Unix password hashes normally contain a 12 bit salt, how can JTR, or any
other cracking program who excepts /etc/shadow lines, be effective at
allowing a user to supply a dictionary list? Lets say for example the salt
was 'foobar' and the password was 'password'.  How do these cracking program
allow a dictionary list to be run on a hash such as  foobarpasswordfoobar? I
can see how brute forcing would work, as well as taking more work overall to
do, but I don't understand how John the Ripper can also crack it by
dictionary. I ask because I don't know.

Thanks.