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From: David Safford <safford@us.ibm.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
	Leonidas Da Silva Barbosa <leosilva@linux.vnet.ibm.com>,
	Ashley Lai <ashley@ashleylai.com>,
	Rajiv Andrade <mail@srajiv.net>,
	Marcel Selhorst <tpmdd@selhorst.net>,
	Sirrix AG <tpmdd@sirrix.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Jeff Garzik <jgarzik@pobox.com>, "Ted Ts'o" <tytso@mit.edu>,
	Kent Yoder <key@linux.vnet.ibm.com>,
	David Safford <safford@watson.ibm.com>,
	Mimi Zohar <zohar@us.ibm.com>,
	"Johnston, DJ" <dj.johnston@intel.com>
Subject: Re: TPMs and random numbers
Date: Wed, 11 Sep 2013 14:47:04 -0400	[thread overview]
Message-ID: <1378925224.26698.90.camel@localhost> (raw)
In-Reply-To: <CALCETrVgiJuw9vj+BhchgzAH06gqEO4TYJyt8wd+2CCy33RQ3Q@mail.gmail.com>

On Wed, 2013-09-11 at 10:49 -0700, Andy Lutomirski wrote:
> On Wed, Sep 11, 2013 at 10:22 AM, David Safford <safford@us.ibm.com> wrote:
> >>On 09/09/2013 02:11 PM, H. Peter Anvin wrote:
> 
> A TPM that has an excellent internal entropy source and is FIPS 140-2
> compliant with no bugs whatsoever may still use Dual_EC_DRBG, which
> looks increasingly likely to be actively malicious.

I don't know of any that do so (it's more complex and slower than
the alternatives). 

> I'd be *much* happier if my system read a few hundred random bytes
> from the TPM at startup and fed those bytes into the kernel's entropy
> pool.  This should IMO happen at startup as early as possible.

I agree completely that the ideal case is a system with good entropy
sources, including a TPM, and all these mixed as early as possible.
But I also think that the existing (certified) TPMs are good enough 
for direct use.

dave



  parent reply	other threads:[~2013-09-11 18:47 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-11 17:22 TPMs and random numbers David Safford
2013-09-11 17:49 ` Andy Lutomirski
2013-09-11 18:45   ` Theodore Ts'o
2013-09-11 19:06     ` Jeff Garzik
2013-09-11 19:08       ` Andy Lutomirski
2013-09-11 19:25         ` H. Peter Anvin
2013-09-11 20:28           ` Theodore Ts'o
2013-09-11 20:44             ` H. Peter Anvin
2013-09-11 18:47   ` David Safford [this message]
2013-09-12 21:57     ` Jörn Engel
2013-09-12 23:38       ` Andy Lutomirski
2013-09-12 23:39       ` Jeff Garzik
2013-09-12 22:13         ` Jörn Engel
2013-09-12 23:51           ` Andy Lutomirski
2013-09-12 22:23             ` Jörn Engel
2013-09-13  2:13               ` Theodore Ts'o
2013-09-13  2:22                 ` Jörn Engel
2013-09-11 22:08   ` Johnston, DJ
  -- strict thread matches above, loose matches on Subject: below --
2013-09-09 21:11 H. Peter Anvin
2013-09-11  1:50 ` Andy Lutomirski

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