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authorStephan Müller2023-09-21 13:48:11 +0200
committerHerbert Xu2023-10-01 16:28:15 +0800
commit04597c8dd6c4b55e946fec50dc3b14a5d9d54501 (patch)
treefdf2eca8b085cf01e1b1a2bd8852cab24c905277 /crypto/jitterentropy-kcapi.c
parent7b8c6aee0d5b864e70c0da82583f9862e374eaf3 (diff)
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.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/crypto/jitterentropy-kcapi.c b/crypto/jitterentropy-kcapi.c
index 7d1463a1562a..1de730f94683 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) {