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| author | Stephan Müller <smueller@chronox.de> | 2023-09-21 13:48:11 +0200 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2023-10-01 16:28:15 +0800 |
| commit | f0be2a5192f007dd2ff2442e9701f5d55fb106a2 (patch) | |
| tree | 0b29f0682ebddbe3a6738ae17a45d7306cb01e38 /crypto/jitterentropy-kcapi.c | |
| parent | 614b521c6bc7adebd0f4bfda137c2d0a41f60f3b (diff) | |
| download | linux-crypto-f0be2a5192f007dd2ff2442e9701f5d55fb106a2.tar.gz linux-crypto-f0be2a5192f007dd2ff2442e9701f5d55fb106a2.zip | |
crypto: jitter - add RCT/APT support for different OSRs
The oversampling rate (OSR) value specifies the heuristically implied
entropy in the recorded data - H_submitter = 1/osr. A different entropy
estimate implies a different APT/RCT cutoff value. This change adds
support for OSRs 1 through 15. This OSR can be selected by the caller
of the Jitter RNG.
For this patch, the caller still uses one hard-coded OSR. A subsequent
patch allows this value to be configured.
In addition, the power-up self test is adjusted as follows:
* It allows the caller to provide an oversampling rate that should be
tested with - commonly it should be the same as used for the actual
runtime operation. This makes the power-up testing therefore consistent
with the runtime operation.
* It calls now jent_measure_jitter (i.e. collects the full entropy
that can possibly be harvested by the Jitter RNG) instead of only
jent_condition_data (which only returns the entropy harvested from
the conditioning component). This should now alleviate reports where
the Jitter RNG initialization thinks there is too little entropy.
* The power-up test now solely relies on the (enhanced) APT and RCT
test that is used as a health test at runtime.
The code allowing the different OSRs as well as the power-up test
changes are present in the user space version of the Jitter RNG 3.4.1
and thus was already in production use for some time.
Reported-by "Ospan, Abylay" <aospan@amazon.com>
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 | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/crypto/jitterentropy-kcapi.c b/crypto/jitterentropy-kcapi.c index 7d1463a1..1de730f9 100644 --- a/crypto/jitterentropy-kcapi.c +++ b/crypto/jitterentropy-kcapi.c @@ -245,7 +245,7 @@ static int jent_kcapi_init(struct crypto_tfm *tfm) crypto_shash_init(sdesc); rng->sdesc = sdesc; - rng->entropy_collector = jent_entropy_collector_alloc(1, 0, sdesc); + rng->entropy_collector = jent_entropy_collector_alloc(0, 0, sdesc); if (!rng->entropy_collector) { ret = -ENOMEM; goto err; @@ -334,7 +334,7 @@ static int __init jent_mod_init(void) desc->tfm = tfm; crypto_shash_init(desc); - ret = jent_entropy_init(desc); + ret = jent_entropy_init(0, 0, desc); shash_desc_zero(desc); crypto_free_shash(tfm); if (ret) { |