Since the version 0.2 the application has significantly changed its behavior. Previously, it added random bytes to the kernel pool whenever it had collected enough of them. But now, the entropy bits are added only if there are less than kernel.random.write_wakeup_threshold of them in the pool. (see l.48 of main.c and l.31-40 of kernel.c in the package's source.) The default value of write_wakeup_threshold is 128, which seems too small for an average system. For example, on my desktop with that default setting I've never seen timer_entropyd-0.2 adding any bytes to the pool. Thus the new version effectively ceases to provide an additional source of unpredictable bytes. Probably, the ebuild should advise users to increase their write_wakeup_threshold value reasonably (up to 512-2048 bits). (NOTE the same may apply to media-sound/audio-entropyd as well.)
I'm not very keen on modifying sysctls from the init script of an unrelated service. Haveged has a settings for that, but the others leave it to the user to set the sysctl afaict. I would say that adding a log to notify the user that they have to change the value is a better choice.
Something along ... timer_entropyd kicks in only when entropy falls below a certain threshold. You may want to modify the threshold's default value to something reasonable (i.e. 1024) by setting the kernel.random.write_wakeup_threshold variable in /etc/sysctl.conf ?
The bug has been referenced in the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=733fa820bffc93de9837abb87e033ebf1b0984d9 commit 733fa820bffc93de9837abb87e033ebf1b0984d9 Author: Georgy Yakovlev <gyakovlev@gentoo.org> AuthorDate: 2021-05-15 18:27:08 +0000 Commit: Georgy Yakovlev <gyakovlev@gentoo.org> CommitDate: 2021-05-15 18:29:31 +0000 profiles/package.mask: mask timer_entropyd for removal Bug: https://bugs.gentoo.org/434900 Bug: https://bugs.gentoo.org/552760 Bug: https://bugs.gentoo.org/790413 Signed-off-by: Georgy Yakovlev <gyakovlev@gentoo.org> profiles/package.mask | 9 +++++++++ 1 file changed, 9 insertions(+)
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=8398ecce45070226a4c1d2bb372f4b0caa4561d0 commit 8398ecce45070226a4c1d2bb372f4b0caa4561d0 Author: Georgy Yakovlev <gyakovlev@gentoo.org> AuthorDate: 2021-06-09 05:29:24 +0000 Commit: Georgy Yakovlev <gyakovlev@gentoo.org> CommitDate: 2021-06-09 05:30:09 +0000 sys-apps/timer_entropyd: treeclean Closes: https://bugs.gentoo.org/434900 Closes: https://bugs.gentoo.org/552760 Signed-off-by: Georgy Yakovlev <gyakovlev@gentoo.org> sys-apps/timer_entropyd/Manifest | 1 - .../files/timer_entropyd-0.1-syslog.patch | 28 --------------- .../timer_entropyd/files/timer_entropyd.initd.1 | 13 ------- sys-apps/timer_entropyd/metadata.xml | 11 ------ sys-apps/timer_entropyd/timer_entropyd-0.3.ebuild | 42 ---------------------- 5 files changed, 95 deletions(-)
