We have to bootstrap arc4random.c, so guard the FenestrasX code to avoid
using it on Linux/macOS.
Reviewed By: cem
Differential Revision: https://reviews.freebsd.org/D26738
Push the root seed version to userspace through the VDSO page, if
the RANDOM_FENESTRASX algorithm is enabled. Otherwise, there is no
functional change. The mechanism can be disabled with
debug.fxrng_vdso_enable=0.
arc4random(3) obtains a pointer to the root seed version published by
the kernel in the shared page at allocation time. Like arc4random(9),
it maintains its own per-process copy of the seed version corresponding
to the root seed version at the time it last rekeyed. On read requests,
the process seed version is compared with the version published in the
shared page; if they do not match, arc4random(3) reseeds from the
kernel before providing generated output.
This change does not implement the FenestrasX concept of PCPU userspace
generators seeded from a per-process base generator. That change is
left for future discussion/work.
Reviewed by: kib (previous version)
Approved by: csprng (me -- only touching FXRNG here)
Differential Revision: https://reviews.freebsd.org/D22839
In most cases this simply builds the file from lib/libc for missing
functions (e.g. strlcpy on Linux etc.). In cases where this is not possible
I've added an implementation to tools/build/cross-build.
The fgetln.c/fgetwln.c/closefrom.c compatibility code was obtained from
https://gitlab.freedesktop.org/libbsd/libbsd, but I'm not sure it makes
sense to import it into to contrib just for these three bootstrap files.
Reviewed By: brooks
Differential Revision: https://reviews.freebsd.org/D25978
ObsoleteFiles.inc:
Remove manual pages for arc4random_addrandom(3) and
arc4random_stir(3).
contrib/ntp/lib/isc/random.c:
contrib/ntp/sntp/libevent/evutil_rand.c:
Eliminate in-tree usage of arc4random_addrandom().
crypto/heimdal/lib/roken/rand.c:
crypto/openssh/config.h:
Eliminate in-tree usage of arc4random_stir().
include/stdlib.h:
Remove arc4random_stir() and arc4random_addrandom() prototypes,
provide temporary shims for transistion period.
lib/libc/gen/Makefile.inc:
Hook arc4random-compat.c to build, add hint for Chacha20 source for
kernel, and remove arc4random_addrandom(3) and arc4random_stir(3)
links.
lib/libc/gen/arc4random.c:
Adopt OpenBSD arc4random.c,v 1.54 with bare minimum changes, use the
sys/crypto/chacha20 implementation of keystream.
lib/libc/gen/Symbol.map:
Remove arc4random_stir and arc4random_addrandom interfaces.
lib/libc/gen/arc4random.h:
Adopt OpenBSD arc4random.h,v 1.4 but provide _ARC4_LOCK of our own.
lib/libc/gen/arc4random.3:
Adopt OpenBSD arc4random.3,v 1.35 but keep FreeBSD r114444 and
r118247.
lib/libc/gen/arc4random-compat.c:
Compatibility shims for arc4random_stir and arc4random_addrandom
functions to preserve ABI. Log once when called but do nothing
otherwise.
lib/libc/gen/getentropy.c:
lib/libc/include/libc_private.h:
Fold __arc4_sysctl into getentropy.c (renamed to arnd_sysctl).
Remove from libc_private.h as a result.
sys/crypto/chacha20/chacha.c:
sys/crypto/chacha20/chacha.h:
Make it possible to use the kernel implementation in libc.
PR: 182610
Reviewed by: cem, markm
Obtained from: OpenBSD
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D16760
