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From: Jason Gunthorpe <jgg@ziepe.ca>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: linux-integrity@vger.kernel.org,
	David Safford <david.safford@ge.com>,
	Pascal Van Leeuwen <pvanleeuwen@verimatrix.com>,
	James Bottomley <James.Bottomley@HansenPartnership.com>,
	Peter Huewe <peterhuewe@gmx.de>, Arnd Bergmann <arnd@arndb.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] tpm: Salt tpm_get_random() result with get_random_bytes()
Date: Tue, 15 Oct 2019 14:04:50 -0300	[thread overview]
Message-ID: <20191015170450.GB5444@ziepe.ca> (raw)
In-Reply-To: <20191015124702.633-1-jarkko.sakkinen@linux.intel.com>

On Tue, Oct 15, 2019 at 03:47:02PM +0300, Jarkko Sakkinen wrote:
> Salt the result that comes from the TPM RNG with random bytes from the
> kernel RNG. This will allow to use tpm_get_random() as a substitute for
> get_random_bytes().  TPM could have a bug (making results predicatable),
> backdoor or even an inteposer in the bus. Salting gives protections
> against these concerns.

Seems like a dangerous use case, why would any kernel user that cared
about quality of randomness ever call a tpm_* API to get quality
random data?

Jason

  reply	other threads:[~2019-10-15 17:04 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-15 12:47 [PATCH] tpm: Salt tpm_get_random() result with get_random_bytes() Jarkko Sakkinen
2019-10-15 17:04 ` Jason Gunthorpe [this message]
2019-10-16 10:38   ` Jarkko Sakkinen
2019-10-16 10:43     ` Jarkko Sakkinen
2019-10-16 16:09       ` Jason Gunthorpe
2019-10-17 16:21         ` Jarkko Sakkinen
2019-10-16  7:02 ` Janne Karhunen
2019-10-16 10:41   ` Jarkko Sakkinen
2019-10-16 11:16     ` Janne Karhunen
2019-10-16 16:23       ` Jarkko Sakkinen

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