crypto: drbg - ignore jitterentropy errors if not in FIPS mode

A subsequent patch will make the jitterentropy RNG to unconditionally
report health test errors back to callers, independent of whether
fips_enabled is set or not. The DRBG needs access to a functional
jitterentropy instance only in FIPS mode (because it's the only SP800-90B
compliant entropy source as it currently stands). Thus, it is perfectly
fine for the DRBGs to obtain entropy from the jitterentropy source only
on a best effort basis if fips_enabled is off.

Make the DRBGs to ignore jitterentropy failures if fips_enabled is not set.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Reviewed-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 5977a72afb03420218cd8f103a69b82902f0fe0c..177983b6ae38b3a6d59ae79b90c61219009de002 100644 (file)
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -1193,11 +1193,14 @@ static int drbg_seed(struct drbg_state *drbg, struct drbg_string *pers,
                        pr_devel("DRBG: (re)seeding with %u bytes of entropy\n",
                                 entropylen);
                } else {
-                       /* Get seed from Jitter RNG */
+                       /*
+                        * Get seed from Jitter RNG, failures are
+                        * fatal only in FIPS mode.
+                        */
                        ret = crypto_rng_get_bytes(drbg->jent,
                                                   entropy + entropylen,
                                                   entropylen);
-                       if (ret) {
+                       if (fips_enabled && ret) {
                                pr_devel("DRBG: jent failed with %d\n", ret);
 
                                /*