I use: cat /proc/sys/kernel/random/entropy_avail To check on the amount of entropy for creating random stuff like keypairs with openssl or random nonces and keys for TLS.. I am using a Cubieboad2. With Fedora-Xfce-armhfp-26-1.5-sda.raw.xz I was seeing numbers in the 3,000. I don't have that image running right now to get an actual number. I just built a system with: Fedora-Server-armhfp-26-1.5-sda.raw.xz I am seeing numbers only in the mid 800s: [root@C2 ~]# cat /proc/sys/kernel/random/entropy_avail 866 [root@C2 ~]# cat /proc/sys/kernel/random/entropy_avail 803 [root@C2 ~]# cat /proc/sys/kernel/random/entropy_avail 828 What is different between these two images? It is the same Cubieboard.

I have also installed rng-tools with some success, but not as much as haveged.

On 08/27/2017 03:31 PM, Peter Robinson wrote: > > On Sun, Aug 27, 2017 at 6:57 PM, Robert Moskowitz <rgm(a)htt-consult.com&gt; > wrote: >> >> I use: >> >> cat /proc/sys/kernel/random/entropy_avail >> >> To check on the amount of entropy for creating random stuff like keypairs >> with openssl or random nonces and keys for TLS.. >> >> I am using a Cubieboad2. >> >> With Fedora-Xfce-armhfp-26-1.5-sda.raw.xz I was seeing numbers in the >> 3,000. >> I don't have that image running right now to get an actual number. >> >> I just built a system with: Fedora-Server-armhfp-26-1.5-sda.raw.xz >> >> I am seeing numbers only in the mid 800s: >> >> [root@C2 ~]# cat /proc/sys/kernel/random/entropy_avail >> 866 >> [root@C2 ~]# cat /proc/sys/kernel/random/entropy_avail >> 803 >> [root@C2 ~]# cat /proc/sys/kernel/random/entropy_avail >> 828 >> >> >> What is different between these two images? It is the same Cubieboard. > > Different images have different services enabled by default, is > rng-tools intsalled by default on server image? Just checked and Package rng-tools-5-9.fc26.armv7hl is already installed And after running dnf, entropy dropped to 324.... > >> I have also installed rng-tools with some success, but not as much as >> haveged. > > There's a quality difference between HW rng vs haveged which provides > entropy but might not be as random as a proper HW rng > I could boot up the workstation Xfce image I have, but I was kind of hoping there was some knowledge here on differences. Other than workstation running something like haveged, what else could be the source of the entropy difference?

On 08/27/2017 04:08 PM, Peter Robinson wrote: > On Sun, Aug 27, 2017 at 8:59 PM, Robert Moskowitz > <rgm(a)htt-consult.com&gt; wrote: >> >> On 08/27/2017 03:31 PM, Peter Robinson wrote: >>> On Sun, Aug 27, 2017 at 6:57 PM, Robert Moskowitz >>> <rgm(a)htt-consult.com&gt; >>> wrote: >>>> I use: >>>> >>>> cat /proc/sys/kernel/random/entropy_avail >>>> >>>> To check on the amount of entropy for creating random stuff like >>>> keypairs >>>> with openssl or random nonces and keys for TLS.. >>>> >>>> I am using a Cubieboad2. >>>> >>>> With Fedora-Xfce-armhfp-26-1.5-sda.raw.xz I was seeing numbers in the >>>> 3,000. >>>> I don't have that image running right now to get an actual number. >>>> >>>> I just built a system with: Fedora-Server-armhfp-26-1.5-sda.raw.xz >>>> >>>> I am seeing numbers only in the mid 800s: >>>> >>>> [root@C2 ~]# cat /proc/sys/kernel/random/entropy_avail >>>> 866 >>>> [root@C2 ~]# cat /proc/sys/kernel/random/entropy_avail >>>> 803 >>>> [root@C2 ~]# cat /proc/sys/kernel/random/entropy_avail >>>> 828 >>>> >>>> >>>> What is different between these two images? It is the same >>>> Cubieboard. >>> Different images have different services enabled by default, is >>> rng-tools intsalled by default on server image? >> >> Just checked and >> >> Package rng-tools-5-9.fc26.armv7hl is already installed >> >> And after running dnf, entropy dropped to 324.... >> >> >> >>>> I have also installed rng-tools with some success, but not as much as >>>> haveged. >>> There's a quality difference between HW rng vs haveged which provides >>> entropy but might not be as random as a proper HW rng >>> >> I could boot up the workstation Xfce image I have, but I was kind of >> hoping >> there was some knowledge here on differences. >> >> Other than workstation running something like haveged, what else >> could be >> the source of the entropy difference? > Different services consuming the available entropy > OK. that is the basic answer. This is the minimal server. There are no connections to it. I am using the serial console. It does have cockpit running by default, but I would hope that is idling and not eating up things like resources. I should probably disable it, as it is not something I would use. Any idea on how I can figure out what is consuming the entropy? My minimal Centos7-arm images have ~2500 for the entropy value.

Robert Moskowitz <rgm(a)htt-consult.com&gt; writes: >>> What is different between these two images? It is the same Cubieboard. >> Different images have different services enabled by default, is >> rng-tools intsalled by default on server image? > Just checked and > > Package rng-tools-5-9.fc26.armv7hl is already installed But is rngd actually running?

> And after running dnf, entropy dropped to 324.... Hmm.