summaryrefslogtreecommitdiffstats
path: root/crypto/rsa.c
diff options
context:
space:
mode:
authorStephan Müller <smueller@chronox.de>2021-11-21 15:14:20 +0100
committerHerbert Xu <herbert@gondor.apana.org.au>2021-11-26 16:25:18 +1100
commit552d03a223eda3df84526ab2c1f4d82e15eaee7a (patch)
treee680fe92fefee834aaadbd5b22ec0b0673ac145f /crypto/rsa.c
parent13389403fe8a978bfc0a866b6d598451feaca212 (diff)
downloadlinux-552d03a223eda3df84526ab2c1f4d82e15eaee7a.tar.bz2
crypto: jitter - consider 32 LSB for APT
The APT compares the current time stamp with a pre-set value. The current code only considered the 4 LSB only. Yet, after reviews by mathematicians of the user space Jitter RNG version >= 3.1.0, it was concluded that the APT can be calculated on the 32 LSB of the time delta. Thi change is applied to the kernel. This fixes a bug where an AMD EPYC fails this test as its RDTSC value contains zeros in the LSB. The most appropriate fix would have been to apply a GCD calculation and divide the time stamp by the GCD. Yet, this is a significant code change that will be considered for a future update. Note, tests showed that constantly the GCD always was 32 on these systems, i.e. the 5 LSB were always zero (thus failing the APT since it only considered the 4 LSB for its calculation). Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/rsa.c')
0 files changed, 0 insertions, 0 deletions