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From:   Stephan Mueller <smueller@chronox.de>
To:     Herbert Xu <herbert@gondor.apana.org.au>
Cc:     linux-crypto@vger.kernel.org
Subject: Re: [PATCH v3] crypto: DRBG - add FIPS 140-2 CTRNG for noise source
Date:   Fri, 03 May 2019 07:11:23 +0200
Message-ID: <2145637.ukeSOrXKR8@tauon.chronox.de>
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References: <1852500.fyBc0DU23F@positron.chronox.de> <5352150.0CmBXKFm2E@positron.chronox.de> <20190503014241.cy35pjinezhapga7@gondor.apana.org.au>
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Am Freitag, 3. Mai 2019, 03:42:41 CEST schrieb Herbert Xu:

Hi Herbert,

> On Thu, May 02, 2019 at 06:38:12PM +0200, Stephan M=FCller wrote:
> > +static int drbg_fips_continuous_test(struct drbg_state *drbg,
> > +				     const unsigned char *entropy)
> > +{
> > +#if IS_ENABLED(CONFIG_CRYPTO_FIPS)
>=20
> This should look like
>=20
> 	if (IS_ENABLED(CONFIG_CRYPTO_FIPS)) {
> 		...
> 	} else {
> 		...
> 	}
>=20
> This way the compiler will see everything regardless of whether
> FIPS is enabled or not.
>=20
> > diff --git a/include/crypto/drbg.h b/include/crypto/drbg.h
> > index 3fb581bf3b87..939051480c83 100644
> > --- a/include/crypto/drbg.h
> > +++ b/include/crypto/drbg.h
> > @@ -129,6 +129,10 @@ struct drbg_state {
> >=20
> >  	bool seeded;		/* DRBG fully seeded? */
> >  	bool pr;		/* Prediction resistance enabled? */
> >=20
> > +#if IS_ENABLED(CONFIG_CRYPTO_FIPS)
> > +	bool fips_primed;	/* Continuous test primed? */
> > +	unsigned char *prev;	/* FIPS 140-2 continuous test value */
> > +#endif
>=20
> You can still use #ifdef here.

The variables would need to be defined unconditionally if we use a runtime=
=20
check in the C code. Is that what you want me to do?

Ciao
Stephan