Linux: How to Create RSA Keys and SSH Agent

Step 1: Generate RSA Key
# Command to generate rsa key for Ubuntu Linux
ssh-keygen -t rsa -b 2048

There are 2 questions:
a. Enter file in which to save the key => press [enter] key to accept default ~/.ssh
b. Enter passphrase => create a password to access rsa key (recommended)

Step 2: Configure SSH Agent

a. Add SSH Key to ssh-agent

$ eval "$(ssh-agent -s)"
Agent pid 95765

b. Setup Bash to Load ssh-agent

# These lines are meant to generate a $HOME/.bashrc file
# Escape characters are added - please remove those if commands are to be extracted
# Add this to ~/.bash_profile on OSX/Linux or ~/.bashrc on Ubuntu

cat<< EOF > ~/.bashrc
#OR APPEND: cat<< EOF >> ~/.bashrc
echo "Loading ~/.bashrc ..."
function start_agent {
    echo "Initialising new SSH agent..."
    /usr/bin/ssh-agent | sed 's/^echo/#echo/' > "\${SSH_ENV}"
    echo succeeded
    chmod 600 "\${SSH_ENV}"
    . "\${SSH_ENV}" > /dev/null
    echo "Key loaded: "
    /usr/bin/ssh-add -L;
# Source SSH settings, if applicable
#i=$(ps -eaf | grep -i ssh-agent |sed '/^$/d' | wc -l | bc -l) # check for service and cast output as integer
#if [ $i > 1 ]; then
#    echo "loading ssh key from its default location..."
#    /usr/bin/ssh-add;
if [ -f "\${SSH_ENV}" ]; then
    . "\${SSH_ENV}" > /dev/null
    ps -ef | grep \${SSH_AGENT_PID} | grep ssh-agent\$ > /dev/null || {

c. Alternative client: how to Configure Putty’s Pageant

Run pageant.exe (if it’s not already started) > Click Add Key > select the correct PPK > Input key file password if required > OK > Close

If using mRemoteNG, go to Tools > External Tools > Configure pageant to automatically load the correct PPK as shown

Leave a Reply

Your email address will not be published. Required fields are marked *