From: George Spelvin <lkml@SDF.ORG>
To: Andy Lutomirski <luto@amacapital.net>
Cc: netdev@vger.kernel.org, w@1wt.eu, aksecurity@gmail.com,
torvalds@linux-foundation.org, edumazet@google.com,
Jason@zx2c4.com, luto@kernel.org, keescook@chromium.org,
tglx@linutronix.de, peterz@infradead.org, tytso@mit.edu,
lkml.mplumb@gmail.com, stephen@networkplumber.org
Subject: Re: Flaw in "random32: update the net random state on interrupt and activity"
Date: Sat, 8 Aug 2020 19:03:43 +0000 [thread overview]
Message-ID: <20200808190343.GB27941@SDF.ORG> (raw)
In-Reply-To: <7E03D29C-2982-43C9-81E6-DB46FF4D369E@amacapital.net>
On Sat, Aug 08, 2020 at 10:07:51AM -0700, Andy Lutomirski wrote:
>> - Cryptographically strong ChaCha, batched
>> - Cryptographically strong ChaCha, with anti-backtracking.
>
> I think we should just anti-backtrack everything. With the "fast key
> erasure" construction, already implemented in my patchset for the
> buffered bytes, this is extremely fast.
The problem is that this is really *amorized* key erasure, and
requires large buffers to amortize the cost down to a reasonable
level.
E,g, if using 256-bit (32-byte) keys, 5% overhead would require generating
640 bytes at a time.
Are we okay with ~1K per core for this? Which we might have to
throw away occasionally to incorporate fresh seed material?
You're right that the simplification in usage is a benefit.
next prev parent reply other threads:[~2020-08-08 19:04 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-08 15:26 Flaw in "random32: update the net random state on interrupt and activity" George Spelvin
2020-08-08 17:07 ` Andy Lutomirski
2020-08-08 18:08 ` Willy Tarreau
2020-08-08 18:13 ` Linus Torvalds
2020-08-08 19:03 ` George Spelvin [this message]
2020-08-08 19:49 ` Andy Lutomirski
2020-08-08 21:29 ` George Spelvin
2020-08-08 17:44 ` Willy Tarreau
2020-08-08 18:19 ` Linus Torvalds
2020-08-08 18:53 ` Willy Tarreau
2020-08-08 20:47 ` George Spelvin
2020-08-08 20:52 ` Linus Torvalds
2020-08-08 22:27 ` George Spelvin
2020-08-09 2:07 ` Linus Torvalds
2020-08-11 16:01 ` Eric Dumazet
2020-08-08 19:18 ` Florian Westphal
2020-08-08 20:59 ` George Spelvin
2020-08-08 21:18 ` Willy Tarreau
2020-08-08 20:08 ` George Spelvin
2020-08-08 20:47 ` Linus Torvalds
2020-08-09 6:57 ` [DRAFT PATCH] random32: make prandom_u32() output unpredictable George Spelvin
2020-08-09 9:38 ` Willy Tarreau
2020-08-09 17:06 ` George Spelvin
2020-08-09 17:33 ` Willy Tarreau
2020-08-09 18:30 ` George Spelvin
2020-08-09 19:16 ` Willy Tarreau
2020-08-10 11:47 ` Willy Tarreau
2020-08-10 12:01 ` David Laight
2020-08-10 14:48 ` Willy Tarreau
2020-08-10 12:03 ` Florian Westphal
2020-08-10 14:53 ` Willy Tarreau
2020-08-10 16:31 ` Linus Torvalds
2020-08-10 16:58 ` Willy Tarreau
2020-08-10 17:45 ` Linus Torvalds
2020-08-10 18:01 ` Willy Tarreau
2020-08-10 21:04 ` Willy Tarreau
2020-08-11 5:26 ` George Spelvin
2020-08-11 5:37 ` Willy Tarreau
2020-08-11 3:47 ` George Spelvin
2020-08-11 3:58 ` Willy Tarreau
[not found] ` <fdbc7d7d-cba2-ef94-9bde-b3ccae0cfaac@gmail.com>
2020-08-09 21:10 ` Marc Plumb
2020-08-09 21:48 ` Linus Torvalds
2020-08-09 13:50 ` Randy Dunlap
[not found] ` <CANEQ_++a4YcwQQ2XhuguTono9=RxbSRVsMw08zLWBWJ_wxG2AQ@mail.gmail.com>
2020-08-09 16:08 ` George Spelvin
-- strict thread matches above, loose matches on Subject: below --
2020-08-12 6:03 Flaw in "random32: update the net random state on interrupt and activity" Sedat Dilek
2020-08-12 6:35 ` Sedat Dilek
2020-08-12 7:13 ` Sedat Dilek
2020-08-12 15:16 ` Eric Dumazet
2020-08-12 16:20 ` Sedat Dilek
2020-08-12 16:24 ` Eric Dumazet
2020-08-12 16:38 ` Sedat Dilek
2020-08-19 9:51 ` Sedat Dilek
2021-01-08 13:08 ` Sedat Dilek
2021-01-08 13:51 ` Sedat Dilek
2021-01-08 15:41 ` Eric Dumazet
2021-01-08 21:32 ` Sedat Dilek
[not found] <9f74230f-ba4d-2e19-5751-79dc2ab59877@gmail.com>
2020-08-05 0:57 ` Marc Plumb
2020-08-05 1:02 ` Linus Torvalds
2020-08-05 2:49 ` Willy Tarreau
2020-08-05 15:34 ` tytso
2020-08-05 16:06 ` Marc Plumb
2020-08-05 19:38 ` Willy Tarreau
2020-08-05 22:21 ` Marc Plumb
2020-08-06 6:30 ` Willy Tarreau
2020-08-06 17:18 ` Marc Plumb
2020-08-07 7:03 ` Willy Tarreau
2020-08-07 16:52 ` Marc Plumb
2020-08-07 17:43 ` Willy Tarreau
[not found] ` <C74EC3BC-F892-416F-A95C-4ACFC96EEECE@amacapital.net>
2020-08-07 18:04 ` Willy Tarreau
2020-08-07 18:10 ` Linus Torvalds
2020-08-07 19:08 ` Andy Lutomirski
2020-08-07 19:21 ` Linus Torvalds
2020-08-07 19:33 ` Andy Lutomirski
2020-08-07 19:56 ` Linus Torvalds
2020-08-07 20:16 ` Andy Lutomirski
2020-08-07 20:24 ` Linus Torvalds
2020-08-07 19:59 ` Marc Plumb
2020-08-07 22:19 ` Willy Tarreau
2020-08-07 22:45 ` Marc Plumb
2020-08-07 23:11 ` Willy Tarreau
2020-08-05 22:05 ` tytso
2020-08-05 23:03 ` Andy Lutomirski
2020-08-06 17:00 ` Marc Plumb
2020-08-05 16:24 ` Jason A. Donenfeld
2020-08-05 16:53 ` Willy Tarreau
2020-08-05 15:44 ` Marc Plumb
2020-08-05 16:39 ` Linus Torvalds
2020-08-05 23:49 ` Stephen Hemminger
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