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Commit b3614763 authored by Stephan Mueller's avatar Stephan Mueller Committed by Herbert Xu
Browse files

crypto: drbg - remove FIPS 140-2 continuous test 



The newly released FIPS 140-2 IG 9.8 specifies that for SP800-90A
compliant DRBGs, the FIPS 140-2 continuous random number generator test
is not required any more.

This patch removes the test and all associated data structures.

Signed-off-by: default avatarStephan Mueller <smueller@chronox.de>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 973fb3fb

crypto/drbg.c

+0 −64
Original line number Diff line number Diff line
@@ -219,48 +219,6 @@ static inline unsigned short drbg_sec_strength(drbg_flag_t flags) 
	}

}



/*

 * FIPS 140-2 continuous self test

 * The test is performed on the result of one round of the output

 * function. Thus, the function implicitly knows the size of the

 * buffer.

 *

 * @drbg DRBG handle

 * @buf output buffer of random data to be checked

 *

 * return:

 *	true on success

 *	false on error

 */

static bool drbg_fips_continuous_test(struct drbg_state *drbg,

				      const unsigned char *buf)

{

#ifdef CONFIG_CRYPTO_FIPS

	int ret = 0;

	/* skip test if we test the overall system */

	if (list_empty(&drbg->test_data.list))

		return true;

	/* only perform test in FIPS mode */

	if (0 == fips_enabled)

		return true;

	if (!drbg->fips_primed) {

		/* Priming of FIPS test */

		memcpy(drbg->prev, buf, drbg_blocklen(drbg));

		drbg->fips_primed = true;

		/* return false due to priming, i.e. another round is needed */

		return false;

	}

	ret = memcmp(drbg->prev, buf, drbg_blocklen(drbg));

	if (!ret)

		panic("DRBG continuous self test failed\n");

	memcpy(drbg->prev, buf, drbg_blocklen(drbg));

	/* the test shall pass when the two compared values are not equal */

	return ret != 0;

#else

	return true;

#endif /* CONFIG_CRYPTO_FIPS */

}



/*

 * Convert an integer into a byte representation of this integer.

 * The byte representation is big-endian
@@ -603,11 +561,6 @@ static int drbg_ctr_generate(struct drbg_state *drbg, 
		}

		outlen = (drbg_blocklen(drbg) < (buflen - len)) ?

			  drbg_blocklen(drbg) : (buflen - len);

		if (!drbg_fips_continuous_test(drbg, drbg->scratchpad)) {

			/* 10.2.1.5.2 step 6 */

			crypto_inc(drbg->V, drbg_blocklen(drbg));

			continue;

		}

		/* 10.2.1.5.2 step 4.3 */

		memcpy(buf + len, drbg->scratchpad, outlen);

		len += outlen;
@@ -733,8 +686,6 @@ static int drbg_hmac_generate(struct drbg_state *drbg, 
			return ret;

		outlen = (drbg_blocklen(drbg) < (buflen - len)) ?

			  drbg_blocklen(drbg) : (buflen - len);

		if (!drbg_fips_continuous_test(drbg, drbg->V))

			continue;



		/* 10.1.2.5 step 4.2 */

		memcpy(buf + len, drbg->V, outlen);
@@ -963,10 +914,6 @@ static int drbg_hash_hashgen(struct drbg_state *drbg, 
		}

		outlen = (drbg_blocklen(drbg) < (buflen - len)) ?

			  drbg_blocklen(drbg) : (buflen - len);

		if (!drbg_fips_continuous_test(drbg, dst)) {

			crypto_inc(src, drbg_statelen(drbg));

			continue;

		}

		/* 10.1.1.4 step hashgen 4.2 */

		memcpy(buf + len, dst, outlen);

		len += outlen;
@@ -1201,11 +1148,6 @@ static inline void drbg_dealloc_state(struct drbg_state *drbg) 
	drbg->reseed_ctr = 0;

	drbg->d_ops = NULL;

	drbg->core = NULL;

#ifdef CONFIG_CRYPTO_FIPS

	kzfree(drbg->prev);

	drbg->prev = NULL;

	drbg->fips_primed = false;

#endif

}



/*
@@ -1244,12 +1186,6 @@ static inline int drbg_alloc_state(struct drbg_state *drbg) 
	drbg->C = kmalloc(drbg_statelen(drbg), GFP_KERNEL);

	if (!drbg->C)

		goto err;

#ifdef CONFIG_CRYPTO_FIPS

	drbg->prev = kmalloc(drbg_blocklen(drbg), GFP_KERNEL);

	if (!drbg->prev)

		goto err;

	drbg->fips_primed = false;

#endif

	/* scratchpad is only generated for CTR and Hash */

	if (drbg->core->flags & DRBG_HMAC)

		sb_size = 0;

include/crypto/drbg.h

+0 −4
Original line number Diff line number Diff line
@@ -117,10 +117,6 @@ struct drbg_state { 
	void *priv_data;	/* Cipher handle */

	bool seeded;		/* DRBG fully seeded? */

	bool pr;		/* Prediction resistance enabled? */

#ifdef CONFIG_CRYPTO_FIPS

	bool fips_primed;	/* Continuous test primed? */

	unsigned char *prev;	/* FIPS 140-2 continuous test value */

#endif

	struct work_struct seed_work;	/* asynchronous seeding support */

	struct crypto_rng *jent;

	const struct drbg_state_ops *d_ops;