check

Checking What SSL and TLS Are In Use

September 15, 2023

Here’s another command to check what version of SSL and TLS is being used.

nmap --script ssl-enum-ciphers -p 443 server.domain.com

Result

PORT    STATE SERVICE
443/tcp open  https
| ssl-enum-ciphers: 
|   TLSv1.2: 
|     ciphers:
...

In this example, only TLSv1.2 is in use. For security purposes, use TLSv1.2 or higher.

Check for new kernel

February 5, 2023

Checking for new kernel on multiple distros.

Redhat, Centos, Fedora, Rocky

rpm -qa kernel
yum list installed kernel

Arch Linux

pacman -Q | grep linux

Fedora

dnf list installed kernel

SUSE

rpm -qa | grep -i kernel
zypper search -i kernel

Debian, Ubuntu, Mint

dpkg --list | grep linux-image

Checking Nameservers

January 15, 2023

Handy little script to see if nameserver is on an array.

#!/bin/bash
declare -a servers=("127.0.0.53" "127.0.0.52" "127.0.0.51")
client=$(cat /etc/resolv.conf | grep nameserver)
for i in "${servers[@]}"
do
  if [[ $client =~ $i ]]
  then 
    using_unbound="true"
    break
  else
    using_unbound="false"
  fi
done
echo $using_unbound "|" $client