SSH to server without password

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The requirement to ssh to server without password

To ssh without password, you must meet the condition:

  • Private key in client ~/.ssh/
  • Public key in server ~/.ssh/authorized_keys

Steps to setup

  1. Create ssh key pairs by ssh-keygen

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    # Generate key
    ssh-keygen

    # Check the generated key pair
    ls ~/.ssh
    -rw-------  1 sing  staff  1679 Jun  8  2018 id_rsa
    -rw-r--r--  1 sing  staff   404 Jun  8  2018 id_rsa.pub

  2. Login to your server

  3. Copy the content of the publicKey (id_rsa.pub) to server’s ~/.ssh/authorized_keys

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    echo "${public key content}" >> ~/.ssh/authorized_keys

  4. Make sure the sshd setting /etc/ssh/sshd_config allow publickey authentication,

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    PubkeyAuthentication yes

    Restart by sudo systemctl restart ssh if you modify the sshd setting.

  5. Modify ssh config (~/.ssh/config) in your client to indicate which ssh key to use

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    Host <server ip>
      IdentityFile ~/.ssh/id_rsa

  6. Verify ssh without password

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    ssh username@serverip