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From: Torsten Duwe <duwe@lst.de>
To: Andy Lutomirski <luto@amacapital.net>
Cc: "Theodore Ts'o" <tytso@mit.edu>, Greg Price <price@mit.edu>,
	Matt Mackall <mpm@selenic.com>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org
Subject: Re: [PATCH resend 0/2] random: Use DRBG sources
Date: Mon, 14 Apr 2014 18:13:59 +0200	[thread overview]
Message-ID: <20140414161359.GD29351@lst.de> (raw)
In-Reply-To: <cover.1397487345.git.luto@amacapital.net>

On Mon, Apr 14, 2014 at 08:49:58AM -0700, Andy Lutomirski wrote:
> [Resent because I forgot to email lkml.  This also surreptitiously
>  fixes a silly typo on a patch description.]
> 
> This is my attempt to come up with a workable way to use so-called
> entropy sources like a TPM to feed /dev/urandom.

Ahem, The TPM RNGs are true HWRNGs, but they are very limited.
Their main purpose is to generate enough bits so that the TPM
can generate a genuine key pair after a few seconds.

Why do you want to put those valuable true random bits into urandom?

> Arguably we should be feeding the input pool as well, but if the

Yes.

> /dev/random algorithm is correct, this shouldn't matter.  I don't want
> sensible use of TPMs for /dev/urandom to block on a long debate about
> /dev/random, so these patches have no effect on /dev/random.

That confuses me a bit.

	Torsten


  parent reply	other threads:[~2014-04-14 16:14 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-04-14 15:49 [PATCH resend 0/2] random: Use DRBG sources Andy Lutomirski
2014-04-14 15:49 ` [PATCH resend 1/2] random: Add add_drbg_randomness to safely seed urandom from crypto hw Andy Lutomirski
2014-04-14 15:50 ` [PATCH resend 2/2] tpm,random: Call add_drbg_randomness after selftest Andy Lutomirski
2014-04-14 16:13 ` Torsten Duwe [this message]
2014-04-14 16:36   ` [PATCH resend 0/2] random: Use DRBG sources Andy Lutomirski
2014-04-14 17:22 ` Andy Lutomirski

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