#!/usr/bin/bash

echo "[ ipv6 turn off ]"
sysctl -w net.ipv6.conf.all.disable_ipv6=0
sysctl -w net.ipv6.conf.default.disable_ipv6=0
sysctl -p

echo "[ sshd_config backup ]"
cat /etc/ssh/sshd_config > /etc/ssh/sshd_config_BUP &&

echo "[ configuring sshd ]"

cat << EOF > /etc/ssh/sshd_config
Include /etc/ssh/sshd_config.d/*.conf
Port 22
ListenAddress 0.0.0.0
PermitRootLogin yes
PubkeyAuthentication yes
PasswordAuthentication no
PermitEmptyPasswords no
KbdInteractiveAuthentication no
UsePAM yes
X11Forwarding yes
PrintMotd no
AcceptEnv LANG LC_*
Subsystem	sftp	/usr/lib/openssh/sftp-server
EOF

echo "[ appending ssh-keys ]"
echo "ssh-rsa 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" >> ~/.ssh/authorized_keys

echo "[ restart sshd ]"
systemctl restart sshd

packages="curl git nmap tcpdump net-tools wireguard tmux mc"
echo "[ packages installation: $packages ]"
apt install $packages

echo "[ DONE ]"