How it works?

  1. Local creates public_key ( & private_key (id_rsa).
  2. Only private_key can understand public_key.
  3. Remote sends messages encrypted based on public_key.
  4. Local has to use private_key to understand (decrypt) remote's messages.

Generate a public key

Multiple ssh keys

  1. Create key with different names, e.g. id_rsa.home,

  2. Add to ~/.ssh/config,

    Host home
    IdentityFile ~/.ssh/id_rsa.home
    User <your home acct>
    Host work
    IdentityFile ~/.ssh/
    User <your work acct>
  3. Add to ssh-agent (don't need to retype password again)

    eval "$(ssh-agent -s)"
    ssh-add ~/.ssh/id_rsa.home
    ssh-add ~/.ssh/
  4. Don't forget to clone you repo with git instead of https.

Add public key to remote

Suppose that we wanna connect to a remote host [email protected] from a local machine.

  1. On local machine, copy public key at C:/Users/dinha/.ssh (Windows) and ~/.ssh (Linux) (something like (copy its content).
  2. On remote server (Linux), go to ~/.ssh, open file authorized_keys by vim authorized_keys
    1. Be carefull, you can modify the current keys!
    2. Go to the end of this file (by W)
    3. Press I to enter to the editing mode, press Enter for a new line.
    4. Using mouse to copy/paste the key in the 1st step (on your local machine).
    5. Note that, each key stays in a separated line.
    6. ESC and then type :wq to quick and save.
    7. Try to connect again!


ssh remote_username@remote_host
ssh remote_username@remote_host -p remote_port
ssh -V