openrc/init.d/urandom.in
Jason A. Donenfeld 076c2552ae Use seedrng for seeding the random number generator
The RNG can't actually be seeded from a shell script, due to the
reliance on ioctls. For this reason, the seedrng project provides a
basic script meant to be copy and pasted into projects like OpenRC and
tweaked as needed: https://git.zx2c4.com/seedrng/about/

This commit imports it into OpenRC and wires up /etc/init.d/urandom to
call it. It shouldn't be called by other things on the system, so it
lives in rc_sbindir.

Closes #506.
Closes #507.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-03-26 19:16:27 -05:00

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#!@SBINDIR@/openrc-run
# Copyright (c) 2007-2022 The OpenRC Authors.
# See the Authors file at the top-level directory of this distribution and
# https://github.com/OpenRC/openrc/blob/HEAD/AUTHORS
#
# This file is part of OpenRC. It is subject to the license terms in
# the LICENSE file found in the top-level directory of this
# distribution and at https://github.com/OpenRC/openrc/blob/HEAD/LICENSE
# This file may not be copied, modified, propagated, or distributed
# except according to the terms contained in the LICENSE file.
export SEEDRNG_SEED_DIR="${seed_dir:-/var/lib/seedrng}"
export SEEDRNG_LOCK_FILE="${lock_file:-/var/run/seedrng.lock}"
export SEEDRNG_SKIP_CREDIT="${skip_credit:-false}"
: ${urandom_seed:=${SEEDRNG_SEED_DIR}/../misc/random-seed}
description="Initializes the random number generator."
depend()
{
after clock
need localmount
keyword -docker -jail -lxc -openvz -prefix -systemd-nspawn
}
save_seed()
{
( # sub shell to prevent umask pollution
umask 077
dd if=/dev/urandom of="$urandom_seed" count=1 2>/dev/null
)
}
start()
{
if [ "$RC_UNAME" = Linux ]; then
seedrng
else
[ -c /dev/urandom ] || return
if [ -f "$urandom_seed" ]; then
ebegin "Initializing random number generator"
cat "$urandom_seed" > /dev/urandom
eend $? "Error initializing random number generator"
fi
rm -f "$urandom_seed" && save_seed
fi
return 0
}
stop()
{
if [ "$RC_UNAME" = Linux ]; then
seedrng
else
ebegin "Saving random seed"
save_seed
eend $? "Failed to save random seed"
fi
}