This reverts commit 2edc017a6e.
We shouldn't be using a shell script here, but the SeedRNG integration
into OpenWRT requires a bit more thought. Etienne raised some important
points immediately after this was merged and planned to send some follow
up commits, but became busy with other things. The points he raised are
important enough that we should actually back this out until it's ready
to go, and then merge it as a cohesive unit. So let's revert this for
now, and come back to it later on.
Cc: Etienne Champetier <champetier.etienne@gmail.com>
Cc: Petr Štetiar <ynezz@true.cz>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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 OpenWRT
and tweaked as needed: <https://git.zx2c4.com/seedrng/about/>.
This commit imports it into the urandom-seed package and wires up the
init scripts to call it. This also is a significant improvement over the
current init script, which does not robustly handle cleaning up of seeds
and syncing to prevent reuse. Additionally, the existing script creates
a new seed immediately after writing an old one, which means that the
amount of entropy might actually regress, due to failing to credit the
old seed.
Closes: https://github.com/openwrt/openwrt/issues/9570
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Petr Štetiar <ynezz@true.cz> [fixed missing INSTALL_DIR]
