endlessh install script

install_endlessh.sh

#!/bin/bash
# automatic installation of endlessh, always works for me at least
#
# run script with:
# wget -q -O /tmp/install_endlessh.sh https://gist.githubusercontent.com/Staubgeborener/d55e42b8b6f951f054af823dfd71e214/raw/ && sudo bash /tmp/install_endlessh.sh

sudo cp /etc/ssh/sshd_config /etc/ssh/sshd_config.bak

sudo apt install git
git clone https://github.com/skeeto/endlessh/
cd endlessh-master

make

sudo cp endlessh /usr/local/bin/
sudo cp util/endlessh.service /etc/systemd/system/

sudo mkdir /etc/endlessh

sudo cat <<EOF > /etc/endlessh/config
Port 22
Delay 10000
MaxLineLength 32
MaxClients 4096
LogLevel 0
BindFamily 0
EOF

sudo cat <<EOF > /etc/systemd/system/endlessh.service
[Unit]
Description=Endlessh SSH Tarpit
Documentation=man:endlessh(1)
Requires=network-online.target

[Service]
Type=simple
Restart=always
RestartSec=30sec
ExecStart=/usr/local/bin/endlessh
KillSignal=SIGTERM

# Stop trying to restart the service if it restarts too many times in a row
StartLimitInterval=5min
StartLimitBurst=4

StandardOutput=journal
StandardError=journal
StandardInput=null

PrivateTmp=true
PrivateDevices=true
ProtectSystem=full
ProtectHome=true
#InaccessiblePaths=/run /var

## If you want Endlessh to bind on ports < 1024
## 1) run:
##     setcap 'cap_net_bind_service=+ep' /usr/local/bin/endlessh
## 2) uncomment following line
AmbientCapabilities=CAP_NET_BIND_SERVICE
## 3) comment following line
#PrivateUsers=true

NoNewPrivileges=true
ConfigurationDirectory=endlessh
ProtectKernelTunables=true
ProtectKernelModules=true
ProtectControlGroups=true
MemoryDenyWriteExecute=true

[Install]
WantedBy=multi-user.target
EOF

sudo setcap 'cap_net_bind_service=+ep' /usr/local/bin/endlessh

sudo systemctl daemon-reload
sudo systemctl enable --now endlessh.service
sudo systemctl start endlessh.service
sudo systemctl status endlessh.service

sudo rm /tmp/install_endlessh.sh
echo -e "\n--------------------------------\nChange line #Port 22 in /etc/ssh/sshd_config to something like Port XXX where XXX is your new ssh port\n--------------------------------\n"