diff options
| author | Stephan Müller <smueller@chronox.de> | 2023-09-21 13:48:59 +0200 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2023-10-01 16:28:15 +0800 |
| commit | 0baa8fab334a4d7017235b72fa8a547433572109 (patch) | |
| tree | 370e777989c37ecaaacbaabd5839abdcde8bd0ac /crypto/jitterentropy-kcapi.c | |
| parent | 59bcfd788552504606e3eb774ae68052379396b6 (diff) | |
crypto: jitter - Allow configuration of oversampling rate
The oversampling rate used by the Jitter RNG allows the configuration of
the heuristically implied entropy in one timing measurement. This
entropy rate is (1 / OSR) bits of entropy per time stamp.
Considering that the Jitter RNG now support APT/RCT health tests for
different OSRs, allow this value to be configured at compile time to
support systems with limited amount of entropy in their timer.
The allowed range of OSR values complies with the APT/RCT cutoff health
test values which range from 1 through 15.
The default value of the OSR selection support is left at 1 which is the
current default. Thus, the addition of the configuration support does
not alter the default Jitter RNG behavior.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/jitterentropy-kcapi.c')
| -rw-r--r-- | crypto/jitterentropy-kcapi.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/crypto/jitterentropy-kcapi.c b/crypto/jitterentropy-kcapi.c index a8e7bbd28c6e..0c6752221451 100644 --- a/crypto/jitterentropy-kcapi.c +++ b/crypto/jitterentropy-kcapi.c @@ -256,7 +256,9 @@ static int jent_kcapi_init(struct crypto_tfm *tfm) crypto_shash_init(sdesc); rng->sdesc = sdesc; - rng->entropy_collector = jent_entropy_collector_alloc(0, 0, sdesc); + rng->entropy_collector = + jent_entropy_collector_alloc(CONFIG_CRYPTO_JITTERENTROPY_OSR, 0, + sdesc); if (!rng->entropy_collector) { ret = -ENOMEM; goto err; @@ -345,7 +347,7 @@ static int __init jent_mod_init(void) desc->tfm = tfm; crypto_shash_init(desc); - ret = jent_entropy_init(0, 0, desc); + ret = jent_entropy_init(CONFIG_CRYPTO_JITTERENTROPY_OSR, 0, desc); shash_desc_zero(desc); crypto_free_shash(tfm); if (ret) { |