How to stop syslog-ng from generating HOSTID on start up
Hi everyone, When starting up, I've noticed that syslog-ng hangs on our embedded system when generating the HOSTID. This is because the HOSTID generation uses RAND_bytes (in_create_host_id <https://github.com/syslog-ng/syslog-ng/blob/66123c955b29298ba6e68cdc77b9a0fdb4aded36/lib/host-id.c#L33>)- which needs entropy (which we don't have enough of, and don't want to generate). The logging is only used locally and there is no need for crypto functionality. Is there a way to avoid generating a cryptographically secure HOSTID on start up? Thank you!
Syslog-ng saves this hostid in a persistent storage, so it should generate it only once, ever. It is stored in the syslog-ng.persist file. Do you keep that across restarts? Does this help your use case? Btw, it should also be possible to populate that persist file with this entry before starting syslog-ng, maybe to a fixed value. Or the lower 4 bytes of your Mac address, etc. persist-tool has a low level interface to add such values while syslog-ng is not running On Wed, Sep 6, 2023, 03:44 Dineth Jayasekera <jayaseke@ualberta.ca> wrote:
Hi everyone,
When starting up, I've noticed that syslog-ng hangs on our embedded system when generating the HOSTID. This is because the HOSTID generation uses RAND_bytes (in_create_host_id <https://github.com/syslog-ng/syslog-ng/blob/66123c955b29298ba6e68cdc77b9a0fdb4aded36/lib/host-id.c#L33>)- which needs entropy (which we don't have enough of, and don't want to generate).
The logging is only used locally and there is no need for crypto functionality. Is there a way to avoid generating a cryptographically secure HOSTID on start up?
Thank you!
______________________________________________________________________________ Member info: https://lists.balabit.hu/mailman/listinfo/syslog-ng Documentation: http://www.balabit.com/support/documentation/?product=syslog-ng FAQ: http://www.balabit.com/wiki/syslog-ng-faq
Thanks Balazs for your help, Yes I was aware of the persist file, but I was having issues initializing it in the first place, and when upgrading to a new firmware load. I was not familiar with persist-tool it looks interesting. I only need to manually add the HOSTID, I did not have issues with the other fields in the persist file. I try creating the persist file with the HOSTID before starting up syslog-ng and see if that fixes the problem. Thanks! On Wed, Sep 6, 2023 at 12:28 AM Balazs Scheidler <bazsi77@gmail.com> wrote:
Syslog-ng saves this hostid in a persistent storage, so it should generate it only once, ever.
It is stored in the syslog-ng.persist file. Do you keep that across restarts? Does this help your use case?
Btw, it should also be possible to populate that persist file with this entry before starting syslog-ng, maybe to a fixed value. Or the lower 4 bytes of your Mac address, etc. persist-tool has a low level interface to add such values while syslog-ng is not running
On Wed, Sep 6, 2023, 03:44 Dineth Jayasekera <jayaseke@ualberta.ca> wrote:
Hi everyone,
When starting up, I've noticed that syslog-ng hangs on our embedded system when generating the HOSTID. This is because the HOSTID generation uses RAND_bytes (in_create_host_id <https://github.com/syslog-ng/syslog-ng/blob/66123c955b29298ba6e68cdc77b9a0fdb4aded36/lib/host-id.c#L33>)- which needs entropy (which we don't have enough of, and don't want to generate).
The logging is only used locally and there is no need for crypto functionality. Is there a way to avoid generating a cryptographically secure HOSTID on start up?
Thank you!
______________________________________________________________________________ Member info: https://lists.balabit.hu/mailman/listinfo/syslog-ng Documentation: http://www.balabit.com/support/documentation/?product=syslog-ng FAQ: http://www.balabit.com/wiki/syslog-ng-faq
______________________________________________________________________________ Member info: https://lists.balabit.hu/mailman/listinfo/syslog-ng Documentation: http://www.balabit.com/support/documentation/?product=syslog-ng FAQ: http://www.balabit.com/wiki/syslog-ng-faq
participants (2)
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Balazs Scheidler
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Dineth Jayasekera