How to use existing SSH key on my newly installed Ubuntu

I have a fresh install of Ubuntu 16.04 on my machine. Now I want to use my existing ssh key on my machine, so that I can use GitHub with my previous activities.

How do I set this up?

2 Answers

If you have a copy of your ssh keys (e.g., on a USB stick) then simply copy the key files to the ~/.ssh/ directory.

E.g.,

cp /path/to/my/key/id_rsa ~/.ssh/id_rsa
cp /path/to/my/key/id_rsa.pub ~/.ssh/id_rsa.pub
# change permissions on file
sudo chmod 600 ~/.ssh/id_rsa
sudo chmod 600 ~/.ssh/id_rsa.pub
# start the ssh-agent in the background
eval $(ssh-agent -s)
# make ssh agent to actually use copied key
ssh-add ~/.ssh/id_rsa

Otherwise, you will need to create a new one and add it to your GitHub account . Be sure to remove the old key from GitHub while you're at it.

Step 1: Give permission to ssh folder

chmod 700 ~/.ssh

Step 2: Give permission to ssh key files

chmod 600 ~/.ssh/id_rsa

chmod 644 ~/.ssh/id_rsa.pub

Step 3: Run the below command on the client machine, that will add the SSH key to the agent.

ssh-add

Now you can confirm with ssh-add -l (again on the client) that it was indeed added.