Cisco password implementation trubs: weakened strength?

Thu Mar 21 11:22:52 UTC 2013

On 3/21/13, jamie rishaw <j at arpa.com> wrote:
> New: (type 4) unsalted sha256

Good for them; DES Crypt and MD5 crypt are dead... however, I hope
they have misspoken then...  because   that move would make no
sense... moving to simple unsalted SHA256  as the new hash type  would
definitely increase the performance of  potential password cracking
attempts against passwords stored at rest,  instead of addressing the
massive increase in cheap computing power  (which will necessitate all
software vendors who are concerned about stored password security,
stop using older crypt algorithms  yesterday).

In other words;  they would be moving to a weaker hashing algorithm if
selecting unsalted SHA -- more hashes per second of SHA256  could be
computed per second on equivalent GPU  than hashes per second of MD5
Crypt.

PBKDF2 at 10k rounds is stronger than MD5 crypt (more time required
for a password cracker); Bcrypt stronger than PBKDF2  with appropriate
work factor selected  (more time _and_  larger amounts of memory space
required  thwarting GPUs); etc.

Also, on what platform have they already used anything stronger than Unix crypt?

As far as I knew, Cisco were always using;  'type 7' password blobs
vigenere based symmetric encryption with a factory-defined key,  type
6 symmetric encrypted storage (with des/aes key obscured from view),
or type 5  basic unix crypt or Poul-Henning Kamp's MD5 crypt algorithm
 used in FreeBSD.

> I'm. not one myself..nor am I a crypto mathnerd
> apparently, Cisco is changing its password schemas.
> old: pbkdf2 by 1k, salted
> vs
> New: (type 4) unsalted sha256
> ..
> discuss.?
>
> there is a cert and Cisco sa on this.. but I'm wondering if anyone has any
> opinions, yea or nay.?

--
-JH