The easiest way to add a copy of your key to a remote server is with the following command:
cat ~/.ssh/id_rsa.pub | ssh user@remotehost 'cat >> ~/.ssh/authorized_keys'
Then you should be able to do this:
ssh [email protected]
And log in without a password.
Creating a new SSH Key
If you don’t have any SSH key. You can create a new one doing this:
ssh-keygen
For safety reasons, you can also have multiple keys according to the systems you are connecting your local machine to, like id_bitbucket_rsa or id_azure_rsa.
Update: 18 October 2023
If you are using MacOS Monterrey and you newly created SSH Key does not work make sure you add it to the keychain:
ssh-add --apple-use-keychain ~/.ssh/your-id-rsa-file
Also, make sure your key is added on your SSH config file
Host * UseKeychain yes AddKeysToAgent yes IdentityFile ~/.ssh/your-id-rsa-file
