On Tue, Nov 30, 2021 at 09:56:41AM +0100, Stephan Mueller wrote:

Am Dienstag, 30. November 2021, 08:55:53 CET schrieb Greg Kroah-Hartman:

Hi Greg,

quoted

On Tue, Nov 30, 2021 at 03:32:38PM +0800, Sandy Harris wrote:

quoted

I think we should eliminate add_disk_randomness() since it does
not work well on current hardware. Also, FIPS requires that
entropy sources be independent & add_interrupt_randomness()
depends on the same disk events so these sources may not be.

This whole "may not be" guessing game when it comes to FIPS
certification is a huge problem.  I have heard of different vendors
getting different feedback and different implementations "passing" in
different ways that totally contradict each other.  It seems that there
is a whole certification industry built up that you can use to try to
pass these tests, but those tests are different depending on the vendor
you use for this, making a total mess.

So perhaps getting solid answers, and having the FIPS people actually
implement (or at least review) the changes and submit them (this is all
open for everyone to see and work on), would be the best thing as that
would at least let us know that this is what they require.

Just as a note: I am working as FIPS tester. I am part of the NIST entropy 
working group which oversees the entropy related requirements. The LRNG's FIPS 
compliant implementation is directly based on those requirements. The LRNG was 
even reviewed by NIST personnel who mentioned that they do not see any 
contradiction to the specification. Finally, we are pursuing to get a separate 
ENT validation from NIST for the LRNG which would indicate that the LRNG meets 
all their requirements.

That's great, so you would be one of the best people to help submit
changes to the existing code to have it be compliant, instead of
replacing it entirely :)

thanks,

greg k-h