From: Denis Vlasenko <vda@ilport.com.ua>
To: Matt Mackall <mpm@selenic.com>
Cc: Andrew Morton <akpm@osdl.org>,
linux-kernel@vger.kernel.org, dbrownell@users.sourceforge.net
Subject: Re: [PATCH 8/14] random: Remove SA_SAMPLE_RANDOM from USB gadget drivers
Date: Sat, 6 May 2006 14:07:02 +0300 [thread overview]
Message-ID: <200605061407.02737.vda@ilport.com.ua> (raw)
In-Reply-To: <9.420169009@selenic.com>
On Friday 05 May 2006 19:42, Matt Mackall wrote:
> Remove SA_SAMPLE_RANDOM from USB gadget drivers
>
> There's no a priori reason to think that USB device interrupts will
> contain "entropy" as defined/required by /dev/random. In fact, most
> operations will be streaming and bandwidth- or CPU-limited.
> /dev/random needs unpredictable inputs such as human interaction or
> chaotic physical processes like turbulence manifested in disk seek
> times.
You may remove SA_SAMPLE_RANDOM from disk interrupts on the same grounds,
because flash-based "IDE" drives have no seek. Indeed, with careful
choice of components, setup, and placement of sniffing equipment
you may construct a case where you can predict interrupt times.
But it's too artificial to matter in real life.
Come on, let's get real. A few low bits of TSC are random enough
(for just about any interrupt source).
Attackers will probably look for easier ways to hack your crypto
than predicting /dev/random.
--
vda
next prev parent reply other threads:[~2006-05-06 11:07 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-05-05 16:42 [PATCH 1/14] random: Remove SA_SAMPLE_RANDOM from floppy driver Matt Mackall
2006-05-05 16:42 ` [PATCH 3/14] random: Make CCISS use add_disk_randomness Matt Mackall
2006-05-05 16:42 ` [PATCH 2/14] random: Remove redundant SA_SAMPLE_RANDOM from NinjaSCSI Matt Mackall
2006-05-05 16:42 ` [PATCH 4/14] random: Change cpqarray to use add_disk_randomness Matt Mackall
2006-05-05 16:42 ` [PATCH 5/14] random: Remove bogus SA_SAMPLE_RANDOM from at91 compact flash driver Matt Mackall
2006-05-05 16:42 ` [PATCH 6/14] random: Remove redundant SA_SAMPLE_RANDOM from touchscreen drivers Matt Mackall
2006-05-05 16:42 ` [PATCH 11/14] random: Remove UML usage of SA_SAMPLE_RANDOM Matt Mackall
2006-05-05 16:42 ` [PATCH 9/14] random: Remove SA_SAMPLE_RANDOM from i2c drivers Matt Mackall
2006-05-05 16:42 ` [PATCH 7/14] random: Remove SA_SAMPLE_RANDOM from network drivers Matt Mackall
2006-05-05 17:13 ` Kyle Moffett
2006-05-05 17:24 ` Matt Mackall
2006-05-05 19:11 ` Theodore Tso
2006-05-05 20:30 ` Stephen Hemminger
2006-05-05 20:34 ` Matt Mackall
2006-05-06 11:55 ` Theodore Tso
2006-05-06 16:48 ` Matt Mackall
2006-05-06 17:29 ` Bernd Eckenfels
2006-05-06 18:05 ` Theodore Tso
2006-05-06 20:33 ` Matt Mackall
2006-05-07 0:17 ` David S. Miller
2006-05-07 1:22 ` Theodore Tso
2006-05-07 5:07 ` Matt Mackall
2006-05-08 21:58 ` Sami Farin
2006-05-24 22:47 ` Marcin Dalecki
2006-05-25 0:08 ` Theodore Tso
2006-05-31 19:29 ` Bill Davidsen
2006-05-07 0:08 ` David S. Miller
2006-05-07 4:59 ` Matt Mackall
2006-05-07 5:46 ` David S. Miller
2006-05-07 16:31 ` Matt Mackall
2006-05-07 13:13 ` Thiago Galesi
2006-05-07 16:00 ` Matt Mackall
2006-05-07 17:00 ` Thiago Galesi
2006-05-08 0:13 ` Theodore Tso
2006-05-08 2:55 ` Matt Mackall
2006-05-08 6:26 ` Pavel Machek
2006-05-08 7:07 ` David S. Miller
2006-05-08 14:05 ` Matt Mackall
2006-05-08 17:21 ` Pavel Machek
2006-05-08 17:27 ` Matt Mackall
2006-05-09 11:23 ` Pavel Machek
2006-05-11 10:05 ` Ph. Marek
2006-05-24 22:35 ` Marcin Dalecki
2006-05-05 21:10 ` David S. Miller
2006-05-05 23:03 ` Matt Mackall
2006-05-05 23:19 ` David S. Miller
2006-05-06 14:08 ` Folkert van Heusden
2006-05-06 15:19 ` Lee Revell
2006-05-07 10:35 ` Folkert van Heusden
2006-05-07 16:33 ` Matt Mackall
2006-05-05 16:42 ` [PATCH 8/14] random: Remove SA_SAMPLE_RANDOM from USB gadget drivers Matt Mackall
2006-05-06 11:07 ` Denis Vlasenko [this message]
2006-05-06 18:16 ` David Brownell
2006-05-06 18:31 ` Matt Mackall
2006-05-05 16:42 ` [PATCH 10/14] random: Remove bogus SA_SAMPLE_RANDOM from mpc52xx serial driver Matt Mackall
2006-05-05 16:42 ` [PATCH 13/14] random: Remove SA_SAMPLE_RANDOM from IRQ fastpath Matt Mackall
2006-05-05 16:42 ` [PATCH 14/14] random: Remove add_interrupt_randomness Matt Mackall
2006-05-05 16:42 ` [PATCH 12/14] random: Remove not very useful SA_SAMPLE_RANDOM from lubbock Matt Mackall
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