From: Stephan Mueller <smueller@chronox.de>
Subject: Re: [PATCH] random: add random_initialized command line param
Date: Tue, 23 Jun 2015 23:47:33 +0200
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References: <4206400.x843ypJTc1@tachyon.chronox.de> <20150623204411.GB30826@amd>
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Cc: Ted Tso <tytso@mit.edu>, linux-crypto@vger.kernel.org,
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To: Pavel Machek <pavel@ucw.cz>
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Am Dienstag, 23. Juni 2015, 22:44:11 schrieb Pavel Machek:

Hi Pavel,

> On Mon 2015-05-18 18:25:25, Stephan Mueller wrote:
> > Make the threshold at which the output entropy pools are considered to
> > be initialized configurable via a kernel command line option. The
> > current integer value of 128 bits is a good default value. However, some
> > user groups may want to use different values. For example, the SOGIS
> > group now requires 125 bits at least (BSI, the participant at that group
> > used to require 100 bits). NIST moved from 80 bits to 112 bits starting
> > with 2014.
> > 
> > It is therefore to be expected that in the future, this threshold may
> > increase for different user groups.
> 
> Speaking of random and kernel parameters... should we add random=<hex
> digits> parameter to pass entropy from bootloader to the kernel?

Everybody can see that string. How do you think that way of providing entropy 
is protected?

> u-boot-SPL does DRAM calibration, for example, and I guess that may
> provide some rather hard to guess values...
> 
> [I initialy misread parameter below as "random_initize=" and thought
> it does exactly this...]
> 								Pavel
> 
> > +	random_initialized= [KNL] Set the threshold in bits at which the
> > +			Linux random number generator considers an output
> > +			entropy pool initialized.
> > +			Format: <int> (must be >= 112 and <= size of output
> > +				       entropy pool in bits)
> > +			Default: 128
> > +


-- 
Ciao
Stephan