Digest stored entropy for CRNG test.
Via the FIPS lab, NIST confirmed:
The CMVP had a chance to discuss this inquiry and we agree that
hashing the NDRNG block does meet the spirit and letter of AS09.42.
However, the CMVP did have a few questions: what hash algorithm would
be used in this application? Is it approved? Is it CAVs tested?
SHA256 is being used here and it will be both approved and CAVs tested.
This means that no raw entropy needs to be kept between RNG seedings, preventing
a potential attack vector aganst the randomness source and the DRBG chains.
It also means the block of secure memory allocated for this purpose is no longer
required.
Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/8790)
This only impacts FIPS mode or someone who has enabled the FIPS 140.2
4.9.2 Conditional Tests. i.e. nobody currently.
Fix a significant issue in the entropy gathering for the continuous RNG
testing. The impact is using an uninitialised buffer instead of the gathered
entropy.
Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/8789)
Refer to FIPS 140-2 section 4.9.2 Conditional Tests for details.
The check is fairly simplistic, being for the entropy sources to not feed
the DRBG the same block of seed material twice in a row. Only the first
DRBG in a chain is subject to this check, latter DRBGs are assumed to be
safely seeded via the earlier DRBGs.
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8599)
