ssh to a server without typing your password

ssh-tutorial.md

How to ssh to a remote server without typing your password

Save yourself a few keystrokes. Follow the steps below:

1. Run this Bash script on your laptop:

   #!/usr/bin/env bash
   
   # The hostname of your remote server.
   host=myserver.com
   
   # Create this folder if it does not exist: ~/.ssh
   mkdir ~/.ssh
   
   # Set the correct permissions (required)
   chmod 700 ~/.ssh
   
   # Generate an RSA key pair for identification with the remote server
   ssh-keygen -t rsa
   
   # Copy your public key to the remote server
   cat ~/.ssh/id_rsa.pub | ssh $host 'cat >> ~/.ssh/authorized_keys'
   
   # ssh is very strict about correct permissions
   ssh $host 'chmod g-w,o-w ~; chmod 700 ~/.ssh; chmod 600 ~/.ssh/authorized_keys'

   At this point, you can connect to your server without typing a password:

   ssh username@myserver.com

2. If you would prefer to type jupiter (7 characters) rather than username@myserver.com (21 characters), create a config file ~/.ssh/config on your laptop, as shown below. You'll be able to use the jupiter alias with: rsync, scp, and ssh.

   # ~/.ssh/config
   
   Host jupiter
       User carl
       HostName myserver.com
   

   At this point, you can connect to your server like this:

   ssh jupiter

3. If you want a single command to do two steps:

   1. First, connect to a login server jupiter
   2. Next, connect to a work server saturn

   Then configure your ~/.ssh/config file as follows:

   # ~/.ssh/config
   
   Host jupiter
       User carl
       Hostname myserver.com
   
   Host saturn
       User carl
       ProxyCommand ssh -qX jupiter nc %h %p
   

   At this point, you can connect to saturn via jupiter like this:

   ssh saturn

Further reading

How to write your own config file:

• http://www.cyberciti.biz/faq/create-ssh-config-file-on-linux-unix/

All available configuration options:

• http://linux.die.net/man/5/ssh_config

You haven't explain where password should be stored. Can you describe this?

You haven't explain where password should be stored. Can you describe this?
hello @mbaev,
I think in this tutorial described steps that were used with a private key without password, and that's why it works without a password

Quick Solution for "passwordless" ssh connection with private key:
first of all call following command one time in your shell (bash):

ssh-add -k ~/.ssh/id_rsa_YOUR_PRIV_key

after this one time command you will never asked for next connection with your private key again in current shell session

Thanks for this great guide

You haven't explain where password should be stored. Can you describe this?
hello @mbaev,
I think in this tutorial described steps that were used with a private key without password, and that's why it works without a password

Quick Solution for "passwordless" ssh connection with private key:
first of all call following command one time in your shell (bash):

ssh-add -k ~/.ssh/id_rsa_YOUR_PRIV_key

after this one time command you will never asked for next connection with your private key again in current shell session

hi i just wanted to know what -k option do ?

in case you have put a passphrase on ssh key where do we put it?

Default path for ssh key is under your home path .ssh (hidden folder)

e.g. İf your account is called "user" than:
/home/user/.ssh/

You haven't explain where password should be stored. Can you describe this?
hello @mbaev,
I think in this tutorial described steps that were used with a private key without password, and that's why it works without a password

Quick Solution for "passwordless" ssh connection with private key:
first of all call following command one time in your shell (bash):
ssh-add -k ~/.ssh/id_rsa_YOUR_PRIV_key
after this one time command you will never asked for next connection with your private key again in current shell session

hi i just wanted to know what -k option do ?

Parameter -k stays for Key. With this parameter you can set the path to your key which will be called to handle.

@AysadKozanoglu sorry that I've asked you the question that way. Thank you for the answer!

it works, thank you