CVS commit: src/sys/arch/arm/sunxi

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Wed Dec 18 02:26:48 UTC 2019

Modified Files:
        src/sys/arch/arm/sunxi: sun8i_crypto.c

Log Message:
Reduce entropy estimate for sun8icrypto TRNG.

NIST's SP800-90B entropy estimation tools put it at no more than .08
bits of entropy per byte of data(!), so estimate 100 bits of data per
bit of entropy.  This is probably not conservative enough -- the NIST
tools were written without knowledge of how this alleged TRNG works!
Knowledge of the physics of how the TRNG is supposed to work could
probably enable a better job at predicting the outputs.

While here, bump the size of data we can sample directly with sysctl
to 4096 bytes.


To generate a diff of this commit:
cvs rdiff -u -r1.8 -r1.9 src/sys/arch/arm/sunxi/sun8i_crypto.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.