Date: Tue, 12 Mar 2002 00:33:34 -0800 From: Terry Lambert <tlambert2@mindspring.com> To: "Crist J. Clark" <cjc@FreeBSD.ORG> Cc: Patrick Thomas <root@utility.clubscholarship.com>, freebsd-hackers@FreeBSD.ORG, freebsd-emulation@FreeBSD.ORG Subject: Re: cryptography implications (privacy) of FreeBSD jail ? Message-ID: <3C8DBD5E.7055B080@mindspring.com> References: <20020311161036.B69654-100000@utility.clubscholarship.com> <20020312000417.F29705@blossom.cjclark.org>
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"Crist J. Clark" wrote: > On Mon, Mar 11, 2002 at 04:13:16PM -0800, Patrick Thomas wrote: > > Let's say I am running in a jail, and say 5 other people are running in > > other, seperate jails on the same machine. > > > > Now lets say I start up pgp, and generate my keys, and generally use pgp > > through the command line in my jail. Or, instead of pgp I do other crypto > > related sensitive activities... > > > > what is my risk here ? Can someone either on the host machine or in one > > of the other jails watch memory on the machine and discern things like my > > keys or passphrases or have very easy access to the data I am decrypting ? > > As always, root on the host ownz you. root in your jail probably does > too. If the jails are set up "promiscuously," I can think of ways > users in other jails could get information, but if they are set up > well, I don't see any straightforward attacks. But I haven't done > exhaustive research. Enable devfs. Disable direct use of specfs, so that user created device nodes are no good. Mount the devfs in the jail, which will create a local instance from the template. Now delete /dev/io, /dev/mem, /dev/kmem out of the devfs. Voila'... it's now as safe as it's possible to be, and the reading of memory other than that mapped into your process address space is not possible, since you can't use /dec/mem or /dev/kmem to map the memory, and you can't use /dev/io to hack the bits on the disk, the hard (and dangerous) way. -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-emulation" in the body of the message
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