nixpkgs/nixos/modules/security/rngd.nix
Alexander Kjeldaas 64311899db Don't let rngd read /dev/tpm0.
Only one process can interact with the TPM module and
that process should be tcsd.  The tpm_rng kernel module
should instead be loaded and /dev/hwrnd be used to
read the TPM random generator.
Also, log which random generator devices are used by
rngd on startup.
2014-04-22 14:05:09 +02:00

39 lines
1 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
{
options = {
security.rngd.enable = mkOption {
type = types.bool;
default = true;
description = ''
Whether to enable the rng daemon, which adds entropy from
hardware sources of randomness to the kernel entropy pool when
available.
'';
};
};
config = mkIf config.security.rngd.enable {
services.udev.extraRules = ''
KERNEL=="random", TAG+="systemd"
SUBSYSTEM=="cpu", ENV{MODALIAS}=="x86cpu:*feature:*009E*", TAG+="systemd", ENV{SYSTEMD_WANTS}+="rngd.service"
KERNEL=="hw_random", TAG+="systemd", ENV{SYSTEMD_WANTS}+="rngd.service"
KERNEL=="tmp0", TAG+="systemd", ENV{SYSTEMD_WANTS}+="rngd.service"
'';
systemd.services.rngd = {
bindsTo = [ "dev-random.device" ];
after = [ "dev-random.device" ];
description = "Hardware RNG Entropy Gatherer Daemon";
serviceConfig.ExecStart = "${pkgs.rng_tools}/sbin/rngd -f -v --no-tpm=1";
restartTriggers = [ pkgs.rng_tools ];
};
};
}