remote-ssh-setup

#!/usr/bin/env bash

echo "NJIT NCAE 2024 Remote SSH Setup Script"
echo

# Check for root.
if [ "$EUID" -ne 0 ]
  then echo "This script must be ran as root."
  exit 1
fi


# Find sudo group.
if (getent group wheel &>/dev/null); then
  echo "Detected sudo group 'wheel'."
  sudo_group=wheel
elif (getent group sudo &>/dev/null); then
  echo "Detected sudo group 'sudo'."
  sudo_group=sudo
elif (getent group admin &>/dev/null); then
  echo "Detected sudo group 'admin'."
  sudo_group=admin
else
  echo "Unable to autodetect sudo group."
  exit 1
fi

# Creates team user.
# $1: Username
# $2: SSH public key.
function createUser {
  echo "Creating team user for $1."
  useradd -c "NJIT $1" -G "$sudo_group" "$1"
  passwd -l $1
  mkdir -p /home/$1/.ssh
  echo $2 > /home/$1/.ssh/authorized_keys
  chown -R ${1}:${1} /home/$1/.ssh
  chmod -R u=rwX,go= /home/$1/.ssh
}

# Create team users. Will add usernames and keys on competition day.
createUser "USER" "SSHKEY"

# Create local access user.
echo "Creating local access user 'njit-local'."
useradd -c "NJIT Local Only" -G "$sudo_group" "njit-local"
echo "Enter password for local access user."
passwd "njit-local"

echo "Disabling SSH password authentication."
sed -i -E 's/#?PasswordAuthentication yes/PasswordAuthentication no/' /etc/ssh/sshd_config

echo "Restarting SSH daemon."
systemctl restart sshd.service