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Here is a link to the tool that will decrypt both passwords.
Cisco is aware, but their fix was to upgrade to the new client.
=20
=20
To: full-disclosure@lists.grok.org.uk=20
Cc: bugtraq@securityfocus.com=20
=20
=20
=20
Dear List,
=20
[1] heise published a news article today.
[2] EvilScientists reverse engineered the algorithm Cisco uses to
_obscufate_ the
passwords.
[3] PoC
=20
Summary :
Cisco uses 3des to encrypt the passwords, however it does so using
a deterministic encryption sheme (no user input) and thus must be
reproducible.
=20
The algorithm [2] found was as follows :
=20
* GetDate - convert to string
* Generate an SHA Hash from that string h1 (20 Bytes)
* h1 is modified into Hash h2
* h1 is modified into Hash h3
* h2 and the first 4 Bytes from h3 give the 3DES Key
* The clear text password no encrypted in 3DES CBC Mode. The IV is the
first 8 Bytes of h1.
* If the size of the clear text password is not a multiple of the
Block size, the differece to the next block is calculcated and padded
with a Digit. -> length of password is known
* A last hash is calculated from the encrypted Password h4
* The value of the Key "enc_UserPassword" is: h1|h4|verschl=FCsseltes =
Passwort
=20
Credits:
[1] http://www.heise.de/newsticker/meldung/64954=20
[2] http://evilscientists.de/blog/?page_id=3D339=20
[3] http://www.evilscientists.de/blog/?d...evealer.rar=20




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>


Here is a link to the tool that will decrypt both passwords.

Cisco is aware, but their fix was to upgrade to the new client.

 

 


 

 

 

Dear List,

 

[1] heise published a news article today.
[2] EvilScientists =
reverse engineered the algorithm Cisco uses to
_obscufate_ the
 =
   passwords.
[3] PoC

 

Summary :
Cisco uses 3des to encrypt the passwords, however it =
does so using
a deterministic encryption sheme (no user input) and thus =
must be
reproducible.

 

The algorithm [2] found was as follows :

 

* GetDate - convert to string
* Generate an SHA Hash from that =
string h1 (20 Bytes)
* h1 is modified into Hash h2
* h1 is modified =
into Hash h3
* h2 and the first 4 Bytes from h3 give the 3DES Key
* =
The clear text password no encrypted in 3DES CBC Mode. The IV is the
fir=
st 8 Bytes of h1.
* If the size of the clear text password is not a =
multiple of the
  Block size, the differece to the next block is =
calculcated and padded
  with a Digit. -> length of password is =
known
* A last hash is calculated from the encrypted Password h4
* =
The value of the Key "enc_UserPassword" is: h1|h4|verschl=FCsseltes =
Passwort

 



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