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: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/drbg.c b/crypto/drbg.c
index ab6ef1d..1b86310 100644 (file)
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -220,48 +220,6 @@ 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;

diff --git a/include/crypto/drbg.h b/include/crypto/drbg.h
index 9756c70..d961b2b 100644 (file)
--- a/include/crypto/drbg.h
+++ b/include/crypto/drbg.h
@@ -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;