OpenSSH ciphers performance benchmark

These are the results of an OpenSSH ciphers performance benchmark with openssh-7.6_p1 on a Raspberry Pi 3. Since arcfour is deprecated and therefore missing on most modern OpenSSH installations, the fastest cipher is chacha20-poly1305@openssh.com with 28,67 MB/s on average.

The script (taken from here):


CIPHERS=$(ssh -Q cipher)
for cipher in $CIPHERS; do
    for i in 1 2 3 ; do
        echo "Cipher: $cipher (try $i)"
        dd if=/dev/zero bs=4M count=1024 2>$TMP_FILE | \
            pv --size 4G | \
            time -p ssh -c "$cipher" localhost 'cat > /dev/null'
        grep -v records $TMP_FILE

OpenSSH ciphers performance benchmark

As csv:

Cipher,Probe A,Probe B,Probe C,(MB/s),AVG

Tags: ssh  

Created: Dec. 6, 2017 | Updated: Dec. 6, 2017

FreeBSD: Add user to group

Here's how to add a user to a group in FreeBSD:

# pw group mod group_name -m user_name

Tags: freebsd  

Created: Nov. 29, 2017 | Updated: Nov. 29, 2017

Remote login with SLiM

This is how you can perform a remote login with SLiM + SSH + VNC:

On the remote computer:

$ su
# x11vnc -auth /run/slim.auth -display :0

On the client it's business as usual:

$ vncviewer [-4|-6] [parameters] [host:displayNum] [parameters]

By now, you should see the SLiM login display.

Tags: vnc   ssh  

Created: Oct. 13, 2017 | Updated: Nov. 24, 2017

Installing Oracle JDK on Devuan

First, install java-package. It's not yet in the Devuan repositories but you can download it from here: https://packages.debian.org/sid/all/java-package/download Just install it via dpkg -i java-package_0.62_all.deb.

Download the latest JDK version from http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html In this case: jdk-8u144-linux-x64.tar.gz

make-jpkg jdk-8u144-linux-x64.tar.gz
sudo dpkg -i oracle-java8-jdk_8u144_amd64.deb

Tags: Java   Devuan  

Created: Aug. 22, 2017 | Updated: Aug. 22, 2017

OpenBSD: entry point at 0x200120

This error can occure when you installed OpenBSD on a Flash Card (for example with a VM and a card reader):

booting hd0a:/bsd: 8404228+1102404 [52+381152+367486]=0x9c7d50
entry point at 0x200120

This happens because the Flash Card had a different name in the VM than it has now in a different computer. OpenBSD was installed with hd0 as the main disk, but it probably has been renamend. So, in the boot loader, set the name right:

set device wd0a
# and also set the baud rate while youre already there
stty com0 38400
set tty com0

This can be made persistent once the system booted:

$ cat boot.conf 
# $OpenBSD: boot.conf,v 1.2 1997/08/06 23:14:10 mickey Exp $
# sample boot.conf file
echo timeout in 5 seconds
stty com0 38400
set tty com0
set device wd0a

Tags: OpenBSD  

Created: Jan. 21, 2017 | Updated: Jan. 21, 2017