The standard Linux SD-Card images that you can get for the DE1-SoC board from the Terasic website have the SSH daemon enabled by default. Through this SSH connection it is possible to log in from a remote terminal or upload files SCP. However, by default you always have to enter a password. This short guide will show how to configure the systems to use SSH keys so no passwords are needed anymore. Furthermore, we will assign a static IP to the board.

This guide is not really specific to the DE1-SoC board. The same steps can be used on any Linux running an SSH server.

Static IP

Before we start on setting up the SSH keys we want to assign a static IP to the DE1-SoC. This way we don’t have to look up it’s IP every time the IP changes.
Assigning a static IP is just a matter of altering the configuration in /etc/network/interface. The DE1-SoC is connected via the ethernet jack to the network. However, the default configuration file also contains configurations for other interfaces such as a second ethernet interface and a WiFi card. We can throw out all configurations but the one for the lo and the eth0 interfaces.
The following configuration file sets the IP of the DE1-SoC to 192.168.1.100:

Setting up the SSH keys

The following guide assumes that your host (desktop computer) is a Unix machine. However, everything works perfectly fine within a Cygwin environment on Windows.

Generating keys

First we have to generate an RSA public and private key pair on our host computer. This is done by using the ssh-keygen program:

For More Details: DE1-SoC: Using SSH keys