[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: SSH session audit



On 02/19/18 04:51, me@risca.eu wrote:
Hi,

I'm co-managing a server with a friend of mine offering ourself some
 basic service (like emails, file sharing, etc). At this time each of
us can freely login on the server via ssh (we trust each others) for
the daily administrative tasks.

I would like to improve the current set up by adding a layer of certification and proofing of the ssh session, because if you know
that you are recorded you'll be enforce to behave better. For this
scope I've found many different possible solution, but quite complex
to be implemented (like ssh proxy that records the session [1]), or
too basic (like using /usr/bin/script). So far none of those that
I've found satisfy me.

About that I remember that some time ago (maybe one or two years ago)
I read a post on planet debian about such a method for session audit.
It was suggesting as an easy to run solution for external consultant:
the recording and encrypting of the remote session was performed
without requiring any proxy, letting to store the session data on a
dumb external host. From what I could remember I think that the idea
was something like recording the session with script like utilities (launched at session login), then periodically encrypting it with gpg
 and publishing on a local folder or on a remote resource. This way
the owner of the system could reliably access the session log, and
the remote person could always prove what he did at during the ssh
session.

That does not sound secure.  See the Byzantine Generals' Problem:

    https://en.wikipedia.org/wiki/Byzantine_fault_tolerance


Do you know about that solution? Or could you suggest something
similar?

Thank you,

risca.

[1] ssh proxy solutions: ssh-bastion, KeyBox


On 02/19/18 08:34, Roberto C. Sánchez wrote:
You might want to consider a whitelist of commands accessible via
sudo. Each access of sudo is logged by the system and if you do not
permit the user modify system logs, then that may meet your
requirements.

+1 for sudo (no comment on the rest).  This book is good:

    https://www.michaelwlucas.com/tools/sudo


David


Reply to: