Re: [NSE] modified ssl-enum-ciphers to indicate policy compliance

[David Fifield <david () bamsoftware com>]

On Wed, Mar 30, 2011 at 09:56:02PM +0000, Lawrence, Gabe wrote:
> Howdy folks,
>
> I'm about to audit a bunch of SSL servers to make sure that they are
> only offering ciphers that we've decided are good. The easiest way for
> me to assess this was to modify the existing ssl-enum-ciphers script
> to read in a file containing ciphers and indicate if a server only
> offered ciphers in that list, as well as making a visual distinction
> for the ones that aren't. Attached is my attempt at this and I figured
> it was worth sharing with the community. I added myself to the author
> variable only so first attempt at Lua wouldn't reflect negatively on
> Mak Kolybabi.
>
> Original output from the script looked like this:
>
> PORT    STATE SERVICE
> 443/tcp open  https
> | ssl-enum-ciphers2:
> |   TLSv1.0
> |     Ciphers (4)
> |       SSL_RSA_FIPS_WITH_3DES_EDE_CBC_SHA
> |       TLS_RSA_WITH_3DES_EDE_CBC_SHA
> |       TLS_RSA_WITH_DES_CBC_SHA
> |       TLS_RSA_WITH_RC4_128_MD5
> |     Compressors (1)
> |_      uncompressed
>
>
> Specifying --script-args goodcipherlist=./test  with test looking like this
>
> cat test
> SSL_RSA_FIPS_WITH_3DES_EDE_CBC_SHA
> TLS_RSA_WITH_3DES_EDE_CBC_SHA
> TLS_RSA_WITH_RC4_128_MD5
>
> Gives you this
>
> PORT    STATE SERVICE
> 443/tcp open  https
> | ssl-enum-ciphers2:
> |   TLSv1.0
> |     Ciphers (4)
> |       SSL_RSA_FIPS_WITH_3DES_EDE_CBC_SHA
> |       TLS_RSA_WITH_3DES_EDE_CBC_SHA
> |       TLS_RSA_WITH_DES_CBC_SHA*
> |       TLS_RSA_WITH_RC4_128_MD5
> |     Compressors (1)
> |       uncompressed
> |_  Compliant = false
>
> So the one marked with a * is the one that took this server out of compliance.
>
> And, no... my test cipher list isn't my dream list ;-)
>
> I'm not on the list so if you wouldn't mind keeping me on the CC for
> any discussion.

Hi Gabe. Nice job on these modifications. You might not have been Cced
on a couple of replies:
        http://seclists.org/nmap-dev/2011/q2/46
        http://seclists.org/nmap-dev/2011/q2/49
I think I agree with Ron: It would be nice if an external data file
classified ciphers into "strong" and "weak". We could add such a file to
the distribution and make the script read it by default. Then for audits
like yours, someone could just modify the file to match their own cipher
requirements.

If you do this, please base your work on the latest version of the
script, which has some minor changes.
http://nmap.org/svn/scripts/ssl-enum-ciphers.nse

David Fifield
_______________________________________________
Sent through the nmap-dev mailing list
http://cgi.insecure.org/mailman/listinfo/nmap-dev
Archived at http://seclists.org/nmap-dev/