It now only returns true so this can be assumed and doesn't need to be
checked.

Sponsored by:	Arm Ltd
Differential Revision:	https://reviews.freebsd.org/D55105

If we get a random number, the NZCV is set to 0b0000.  Then
"cset %w1, ne" will test whether Z == 0 and set %w1 to 1 if so.
More specifically, "cset %w1, ne" maps to "csinc %w1, wzr, wzr, eq",
which stores 0 in %w1 when NZCV == 0b0100 and 1 otherwise.

Thus, on a successful read we expect ret != 0, so the loop condition
needs to be fixed.  In practice this means that we would end up trying
to fetch entropy up to ten times in a row.  If all attempts are
successful, the last will be returned, otherwise no entropy will be
returned.

Reported by:	Kevin Day <kevin@your.org>
Reviewed by:	andrew
Fixes:		9eecef052155 ("Add an Armv8 rndr random number provider")
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D54259

and one that will be with us in the long-term future.
(this helps reduce diffs in the future and for down-stream users
that trim entropy sources).  Also, move deprecated (removed in 16.0)
sources to the bottom of the list to reduce changes to 15.x.

Reviewed by:	glebius
Obtained from:	Juniper Networks
Differential Revision:	https://reviews.freebsd.org/D53311

Ensure that the number of elements of random_source_descr[]
and fxrng_ent_char[] matches that of enum random_entropy_source.

Reviewed by:	cem
Differential Revision: https://reviews.freebsd.org/D53255

The Hifn 7955 & 7956 only supports deprecated & NIST disallowed
algorithms (NIST SP800-224idp): SHA1 and SHA1-HMAC.

Furthermore the entropy RNG of the Hifn 7751, 7951, 7811, 7955,
and 7956 has no NIST Entropy Source Validation (ESV) certificate
and cannot be used in a FIPS-140-3 nor Common Criteara environment.

Furthermore the most prolific instance for FreeBSD was the
Soekris Engineering vpn1201, vpn1211, vpn1401, and vpn1411
offerings.  These are all 32-bit only processors.  The i386
kernel was de-supported in 15.0.

Reviewed by:	jhb
Differential Revision:	https://reviews.freebsd.org/D53182

Reviewed by: cem
Fixes: 1492c8c0d qcom_rnd: add initial qualcomm prng driver.
Fixes: 9eecef052 Add an Armv8 rndr random number provider
Fixes: b2f8b2dc8 sys: Add an SMCCC Random Number Generator driver
Differential Revision:	https://reviews.freebsd.org/D53292

Reviewed by: cem
Fixes: 3a1298 random: add RDSEED as a provably unique entropy source
Differential Revision:	https://reviews.freebsd.org/D53291

It was used for Octeon MIPS and all producers have been removed
from the source tree.

Reviewed by: emaste
Differential Revision:	https://reviews.freebsd.org/D53146

NIST SP800-90B allows for only a single entropy source to be claimed
in a FIPS-140-3 certificate.  In addition, only hardware sources that
have a NIST Entropy Source Validation (ESV) certificate, backed by
a SP800-90B Entropy Assessment Report, are usable.  Intel has obtained
ESV certificates for several of their processors, so RDSEED is a
FIPS-140-3 suitable entropy source.

However, even though RDRAND is seeded by RDSEED internally, RDRAND
would need a RBG certificate and CAVP testing run on the DRBG in order
to use it for FIPS-140-3 (SP800-90B) purposes.  So we need to know
down in the CSPRNG-subsystem which source the entropy came from.

In light of the potential issues surrounding AMD Zen 5 CPU's RDSEED
implementation[*], allow RDSEED to be disabled in loader.conf.
[*] https://www.phoronix.com/news/AMD-EPYC-Turin-RDSEED-Bug

Reviewed by:	cem
MFC after:	3 days
Sponsored by:	Juniper Networks
Differential Revision:	https://reviews.freebsd.org/D53150

Otherwise we get a NULL pointer dereference when writing to /dev/random.

PR:		288826
Reviewed by:	cem
MFC after:	1 week
Fixes:		fa8db724ae6e ("random: Treat writes to /dev/random as separate from /entropy")
Differential Revision:	https://reviews.freebsd.org/D52633