On Wed, Aug 11, 2010 at 4:09 PM, Alan McKinnon <firstname.lastname@example.org> wrote:
On Thursday 12 August 2010 00:11:12 Bill Longman wrote:
> On 08/11/2010 01:30 PM, Alan McKinnon wrote:
> > I refuse to implement password expiration policies and have a vast array
> > of literature to back me up when some dimwit damager gets on his
> > expiration high horse.
> > My users pick their own passwords - I present a list of 5 from apg and
> > let them pick one. Accounts do expire if they go unused for 90 days, but
> > not passwords.
> > What put me onto this policy? I found Gartner recommending password
> > expiration. I find the best security possible is always the opposite of
> > what Gartner says. Discovering how the AD admins in the company go about
> > their jobs was the convincing straw :-)
> The bigger buggerboo I see is the "password complexity" [il]logic.
> There's this vapid requirement of all these different types of
> characters needed in one's password, yet the thing you really want to
> enforce is adequate entropy. If my password is an entire sentence, it
> will not be brute-forced, even if I used just ASCII A-z. There's just
> too much key space in 4.7^32. At 10^5 attempts per second, you're likely
> to find the answer in half a billion years. I hope your keyboard still
> works, let alone exists....
Your reasoning makes sense, until you consider password length limits imposed
Cisco routers authenticating via Tacacs for instance often support nothing
more than DES hashing <yuck>. The hash routines accept up to 10 characters for
a password but only use the first 8 to calculate the hash.
There are Solaris version nowhere near EOL yet that have similar limits.
All this makes my life as a system integrator cum authenticate go-to guy very
tricky indeed. Luckily management tends to say "Just do what Alan says. It
makes him shut up and go away".
p.s. dig the use of "vapid". Wonderful word, truly splendid. Communicates in 5
letters something that takes paragraphs any other way. I shall make a note for
alan dot mckinnon at gmail dot com
Absolutely. If you do not change your ENCRYPT_METHOD or your PASS_MAX_LEN in your login.defs file and are still relying on the back end's ability to safely store your passwords in DES format, well, you're in trouble.