[OpenAFS-devel] Re: [OpenAFS] Encrypted connections by default in OpenAFS 1.8?

[chas williams - CONTRACTOR]

On Fri, 27 Feb 2015 22:09:12 -0500
Jeffrey Altman <jaltman@your-file-system.com> wrote:

> On 2/27/2015 9:51 PM, Jason Edgecombe wrote:
> > ** file server option to force authenticated access to use encryption
> 
> The client needs to be told the connection policy prior to connection
> establishment (that is what "fs setcrypt" does).  A file server can
> choose to ignore a connection but by that time the data you wish to be
> secure has already been transmitted in the clear.  If the connection is
> rejected by the file server and the clear retransmits the same request
> using a new encryption connection, the client has now given known
> plaintext to an attacker to use to determine the encryption key.

While not a security expert, I think the only problem with the scheme
would be that the current encryption provided by OpenAFS is not
semantically secure (anymore).  When rxkg is available one should be
able to choose an encryption (AES for example) that would defeat a chosen
plaintext attack as well as a known plaintext attack which would protect
any keys in use.