The road to removing Samba's internal copy of AES (and perhaps DES?)

[Andreas Schneider]

On Monday, 2 September 2019 04:03:57 CEST Andrew Bartlett via samba-technical 
wrote:
> G'Day,
> 
> I wanted to write to update the list on where we at at with removing
> cryptographic code from Samba.
> 
> We now absolutely rely on GnuTLS 3.4.7 or later, which has allowed use
> to delete a great deal of such duplicate code.
> 
> We do still have AES code, for the AES CFB8 and CMAC functions.
> 
> These could probably be open-coded against raw AES routines from
> GnuTLS, but for now I would rather not go down that route.
> 
> The operating systems that do not supply that[1], in our CI system are:
>  - CentOS7
>  - Ubuntu 16.04
>  - Ubuntu 18.04
>  - Debian 9
> 
> By April 2020 we should have a new Ubuntu LTS, Debian 10 is already out
> and CentOS8 will be available.  (And we already backport GnuTLS for
> CentOS7 regardless).
> 
> So I would propose we remove the fallback internal code after Ubuntu
> 20.04 is released, or discuss it earlier if we can get a newer backport
> package for the above.
> 
> On a related note, I plan to experiment with implementing our DES code
> via GnuTLS using the CBC-DES cipher and an all-zero IV.  That may let
> us remove that code as well, becoming essentially crypto-free and
> therefore honouring FIPS mode correctly in all cases.  Do let me know
> if you happen to experiment in this area so I don't double-up!

That's an interesting idea!

I'm currently working on further performance improvements for SMB3 encryption. 


	Andreas

-- 
Andreas Schneider                      asn at samba.org
Samba Team                             www.samba.org
GPG-ID:     8DFF53E18F2ABC8D8F3C92237EE0FC4DCC014E3D