Quite a lot of time spent in ssh_get_random

2021-02-19 Thread Richard W.M. Jones
I've been profiling our SSH plugin: https://gitlab.com/nbdkit/nbdkit/-/tree/master/plugins/ssh http://oirase.annexia.org/tmp/ssh_get_random.svg One observation is it seems to spend a lot of time in ssh_get_random; something like a third of the time in sftp_packet_write is spent there. Is there an

Re: Quite a lot of time spent in ssh_get_random

2021-02-19 Thread Aris Adamantiadis
Hi Rich, I'm a bit surprised that it's taking so much resource. It's probably because it's rehashing the whole entropy pool every time we read it. packet_send uses random input in the padding field. I'm not sure that simply using zeroes would be fine, but we certainly don't need very high qua

Re: Quite a lot of time spent in ssh_get_random

2021-02-19 Thread Richard W.M. Jones
On Fri, Feb 19, 2021 at 06:37:05PM +0100, Aris Adamantiadis wrote: > Hi Rich, > > I'm a bit surprised that it's taking so much resource. It's probably > because it's rehashing the whole entropy pool every time we read it. > packet_send uses random input in the padding field. I'm not sure > that si

Re: Quite a lot of time spent in ssh_get_random

2021-02-20 Thread Andreas Schneider
On Friday, 19 February 2021 19:35:16 CET Richard W.M. Jones wrote: > Hmm, I don't *think* so, although I'm not certain I would know > how to tell this. Hi Rich, I don't think that you run in FIPS mode. On Fedora we have: fips-mode-setup --check Andreas

Re: Quite a lot of time spent in ssh_get_random

2021-02-20 Thread Richard W.M. Jones
On Sat, Feb 20, 2021 at 07:34:12PM +0100, Andreas Schneider wrote: > On Friday, 19 February 2021 19:35:16 CET Richard W.M. Jones wrote: > > Hmm, I don't *think* so, although I'm not certain I would know > > how to tell this. > > Hi Rich, > > I don't think that you run in FIPS mode. On Fedora we h