SSH Keys Authentication

SSH Keys Authentication 2014/07/29

	Configure SSH server to login with Keys Authentication. Create a private key for client and a public key for server to do it.
[1]	Create key pair for each user, so login with a common user and work it like follows.

# create key pair [cent@dlp ~]$  ssh-keygen -t rsa  Generating public/private rsa key pair. Enter file in which to save the key (/home/cent/.ssh/id_rsa):    # Enter Created directory '/home/cent/.ssh'. Enter passphrase (empty for no passphrase):    # set passphrase (set no passphrase to Enter with empty) Enter same passphrase again: Your identification has been saved in /home/cent/.ssh/id_rsa. Your public key has been saved in /home/cent/.ssh/id_rsa.pub. The key fingerprint is: 38:f1:b4:6d:d3:0e:59:c8:fa:1d:1d:48:86:f0:fe:74 cent@dlp.server.world The key's randomart image is: [cent@dlp ~]$  mv ~/.ssh/id_rsa.pub ~/.ssh/authorized_keys  [cent@dlp ~]$  chmod 600 ~/.ssh/authorized_keys

[2]	Transfer the secret key created on the Server to a Client, then it's possbile to login with keys authentication.

[cent@www ~]$  mkdir ~/.ssh  [cent@www ~]$  chmod 700 ~/.ssh # copy the secret key to local ssh directory [cent@www ~]$  scp cent@10.0.0.30:/home/cent/.ssh/id_rsa ~/.ssh/  cent@10.0.0.30's password: id_rsa [cent@www ~]$  ssh -i ~/.ssh/id_rsa cent@10.0.0.30  Enter passphrase for key '/home/cent/.ssh/id_rsa':    # passphrase Last login: Wed Jul 30 21:37:19 2014 from www.server.world  [cent@dlp ~]$    # just logined

[3]	If you set "PasswordAuthentication" no, it's more secure.

[root@dlp ~]#  vi /etc/ssh/sshd_config # line 78: turn to "no" PasswordAuthentication  no [root@dlp ~]#  systemctl restart sshd

SSH Keys Auth from Windows Client

	It's the example to login to SSH server from Windows Client. It uses Putty on here. Transfer a secret key to Windows Client first.
[4]	Download "Puttygen.exe" from Putty Site and save it under the Putty directory. Next execute it and click "Load" button.

[5]	Specify the secret key which you downloaded, then passphrase is required like follows, answer it.

[6]	Click "Save private key" button to save it under a folder you like with any file name you like.

[7]	Start Putty and open [Connection]-[SSH]-[Auth] on the left menu, then select the "private_key" which was just saved above.

[8]	Back to the [Session] on the left menu and connect to the SSH server.

[9]	The passphrase is required to input, then answer it. If it's correct passphrase, it's possible to login normally like follows.