From: Tomas Mraz <tmraz@redhat.com>
To: "Austin S. Hemmelgarn" <ahferroin7@gmail.com>,
Stephan Mueller <smueller@chronox.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>, "David Jaša" <djasa@redhat.com>,
"Andi Kleen" <andi@firstfloor.org>,
sandyinchina@gmail.com,
"Jason Cooper" <cryptography@lakedaemon.net>,
"John Denker" <jsd@av8n.com>,
"H. Peter Anvin" <hpa@linux.intel.com>,
"Joe Perches" <joe@perches.com>, "Pavel Machek" <pavel@ucw.cz>,
"George Spelvin" <linux@horizon.com>,
linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 0/5] /dev/random - a new approach
Date: Tue, 21 Jun 2016 15:19:56 +0200 [thread overview]
Message-ID: <1466515196.17017.8.camel@redhat.com> (raw)
In-Reply-To: <6b8c8f6a-862a-3e7c-e950-75cd93cdc1f7@gmail.com>
On Út, 2016-06-21 at 09:05 -0400, Austin S. Hemmelgarn wrote:
> On 2016-06-20 14:32, Stephan Mueller wrote:
> >
> > [1] http://www.chronox.de/jent/doc/CPU-Jitter-NPTRNG.pdf
> Specific things I notice about this:
> 1. QEMU systems are reporting higher values than almost anything
> else
> with the same ISA. This makes sense, but you don't appear to have
> accounted for the fact that you can't trust almost any of the entropy
> in
> a VM unless you have absolute trust in the host system, because the
> host
> system can do whatever the hell it wants to you, including
> manipulating
> timings directly (with a little patience and some time spent working
> on
> it, you could probably get those number to show whatever you want
> just
> by manipulating scheduling parameters on the host OS for the VM
> software).
You have to trust the host for anything, not just for the entropy in
timings. This is completely invalid argument unless you can present a
method that one guest can manipulate timings in other guest in such a
way that _removes_ the inherent entropy from the host.
--
Tomas Mraz
No matter how far down the wrong road you've gone, turn back.
Turkish proverb
(You'll never know whether the road is wrong though.)
next prev parent reply other threads:[~2016-06-21 13:27 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-31 18:37 [PATCH v4 0/5] /dev/random - a new approach Stephan Mueller
2016-05-31 18:37 ` [PATCH v4 1/5] crypto: DRBG - externalize DRBG functions for LRNG Stephan Mueller
2016-05-31 18:38 ` [PATCH v4 2/5] random: conditionally compile code depending on LRNG Stephan Mueller
2016-05-31 18:39 ` [PATCH v4 3/5] crypto: Linux Random Number Generator Stephan Mueller
2016-05-31 18:39 ` [PATCH v4 4/5] crypto: LRNG - enable compile Stephan Mueller
2016-05-31 18:39 ` [PATCH v4 5/5] random: add interrupt callback to VMBus IRQ handler Stephan Mueller
2016-05-31 22:34 ` [PATCH v4 0/5] /dev/random - a new approach George Spelvin
2016-06-15 16:17 ` David Jaša
2016-06-15 16:58 ` Stephan Mueller
2016-06-17 13:56 ` David Jaša
2016-06-17 15:26 ` Sandy Harris
2016-06-18 8:22 ` Stephan Mueller
2016-06-18 8:21 ` Stephan Mueller
2016-06-18 14:44 ` Theodore Ts'o
2016-06-18 16:31 ` Stephan Mueller
2016-06-20 17:07 ` Austin S. Hemmelgarn
2016-06-20 18:32 ` Stephan Mueller
2016-06-21 13:05 ` Austin S. Hemmelgarn
2016-06-21 13:19 ` Tomas Mraz [this message]
2016-06-21 17:18 ` Austin S. Hemmelgarn
2016-06-21 17:23 ` Stephan Mueller
2016-06-21 17:54 ` Austin S. Hemmelgarn
2016-06-21 18:05 ` Stephan Mueller
2016-06-21 13:20 ` Stephan Mueller
2016-06-21 17:51 ` Austin S. Hemmelgarn
2016-06-21 18:04 ` Stephan Mueller
2016-06-21 19:31 ` Austin S. Hemmelgarn
2016-06-22 5:16 ` Stephan Mueller
2016-06-22 12:54 ` Austin S. Hemmelgarn
2016-06-22 13:25 ` Stephan Mueller
2016-06-21 13:42 ` Pavel Machek
2016-06-21 17:17 ` Austin S. Hemmelgarn
2016-06-21 12:25 ` David Jaša
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