[p2p-hackers] amicima MFP and crypto upgrades

[David Barrett]

On Sat, 17 Dec 2005 1:58 pm, coderman wrote:
> On 12/17/05, Matthew Kaufman <matthew at matthew.at> wrote:
>>  ...
>>  2. We've significantly upgraded the "MFP defcrypto" default 
>> cryptographic
>>  plug-in.
>
> i forgot to mention this previously but it is always a good idea to
> lock memory pages where key material and cipher state resides.

I'm not sure I follow how this helps: who is it protecting against?  If 
you don't want the user to get access to cipher info, requiring root 
access isn't much of a barrier (any hacker will have root on his own 
box).  And one user can't access the memory of another user's 
processes.  I'm not disputing the technique, I just don't understand 
when to apply it.

For example, just the other day I was interviewing a candidate (did I 
mention we are hiring?) who aggregates poker stats on other players.  
Despite all sorts of clever on-the-wire encryption, he just figured out 
where all the stats are kept in plaintext in memory and tapped into 
that.  Doh!

Ultimately, it's never a good idea to send data to a client that you 
don't want to fall into the wrong hands.  Memory protection might stop a 
non-root user from accessing his own memory, but this seems like a 
boundary case (unless I'm misunderstanding it).

-david