Re: [PATCH] crypto: add optional continuous repetition test toentropy store based rngs

From: Neil Horman
Date: Fri Jun 12 2009 - 10:23:36 EST

On Thu, Jun 04, 2009 at 09:48:16PM -0400, Neil Horman wrote:
> On Fri, Jun 05, 2009 at 10:30:06AM +1000, Herbert Xu wrote:
> > On Thu, Jun 04, 2009 at 08:04:56PM -0400, Neil Horman wrote:
> > >
> > > Not sure what to do about this. The intent is to provide the external reference
> > > to the fips_enabled flag (which is either defined as an extern in or #defined to
> > > 0 dependent on CONFIG_CRYPTO_FIPS). I can cut'n'paste the code block from the
> > > include file and put it in here, but that seems like a worse solution to me.
> > > Let me know your thoughts, and I can change this accordingly.
> >
> > You can put the fips flag into its own header file, e.g., linux/fips.h.
> >
> Ok, that seems like a reasonable idea. new patch below
> Change Notes:
> 1) Moved fips_enabled flag into its own header, included in all the appropriate
> places
> 2) removed flags field from entropy store, keying continuous test on the
> non-null status of the last_data pointer
> FIPS-140 requires that all random number generators implement continuous self
> tests in which each extracted block of data is compared against the last block
> for repetition. The ansi_cprng implements such a test, but it would be nice if
> the hw rng's did the same thing. Obviously its not something thats always
> needed, but it seems like it would be a nice feature to have on occasion. I've
> written the below patch which allows individual entropy stores to be flagged as
> desiring a continuous test to be run on them as is extracted. By default this
> option is off, but is enabled in the event that fips mode is selected during
> bootup.
> Neil
> Signed-off-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
Ping, I don't see that this got picked up in the crypto tree. Are there
subsequent objections?


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