Password less SSH login (ssh-keygen)

SSH is often used to login from one machine to another machine, There are number of methods to achieve this but mostly in every method it requires authentication..... It also does requires authentication but for one time only i.e. for the first time you need to do a setup and for rest of the times when you will try to login via ssh it will not ask for any password.

For achieving this you just need to generate your own personal set of private/public key pair. ssh-keygen is used to generate that key pair for you.


A HOWTO for generating your own private/public key pair is given below:

Firstly generate your private/public key pair by following command:

[admin@sunny Desktop]$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/admin/.ssh/id_rsa): [Press enter if you want to save your keys to default location]
Enter passphrase (empty for no passphrase): [Enter your passphrase] 
Enter same passphrase again:  [Enter your passphrase again to verify]
Your identification has been saved in /home/admin/.ssh/id_rsa. 
Your public key has been saved in /home/admin/.ssh/id_rsa.pub.
The key fingerprint is:
52:17:88:67:f9:ae:03:e2:59:39:97:f9:7d:95:b6:ed admin@sunny.example.com
The key's randomart image is:
+--[ RSA 2048]----+
|       . o.      |
|      . =  .     |
|       o...      |
|       . ..      |
|      ..S+      .|
|    . =.+ .    o.|
|   . + + o .  ..o|
|    o   o . . ...|
|         .   . .E|
+-----------------+

Now just copy your public key to remote machine, in this case I have generated key pair for server.example.com and copied server's public key to client's machine via following command. 

[admin@sunny .ssh]$ ssh-copy-id -i ~/.ssh/id_rsa.pub client@192.168.86.129
client@192.168.86.129's password:  [Enter the password for the first time]
Now try logging into the machine, with "ssh 'client@192.168.86.129'", and check in:

  .ssh/authorized_keys

to make sure we haven't added extra keys that you weren't expecting.

[admin@sunny .ssh]$


Now when you will try to login to client's machine it will not prompt for the password.

[admin@sunny ~]$ ssh client@192.168.86.129
Last login: Thu Aug  9 10:45:35 2012 from server.redhat.com
[client@client ~]$


Comments

Post a Comment

Popular posts from this blog

Installing Tomcat8 on RHEL6

Image
Apache-HTTP v/s Apache-Tomcat: The basic difference is Apache-Tomcat is written in Java but Apache-HTTP is written in C. Apart from this Apache-Tomcat is used as a webserver as well as to deploy Java Servlet's and JSP's [Java server pages] so basically Apache-Tomcat is used to serve Java Technologies whereas Apache-HTTP is used to serve HTTP. Prerequisites: Appropriate version of JRE [Java run-time environment] for instance jre1.7 is required to run tomcat-8[.X.X]. Tomcat binaries, for version 8 check this link . Sudo/Root access to the machine. Step1: Install JRE Download JRE from Java's official website. You can keep Java at any location but for my ease I have kept both Tomcat and Java in /opt. # cd /opt # cp jre-7u45-linux-x64.tar.gz . # tar -zxvf jre-7u45-linux-x64.tar.gz  The above command will create a folder with JRE binaries. In my case it was "jre1.7.0_45". Now set JRE_HOME [Required by Tomcat] and PATH. export JRE_HOME=/opt/jre1.7.
Read more

Manage existing resources via Helm

Manage existing resources via Helm Helm is really a very powerful tool for managing Kubernetes objects. With a single command, we can install or upgrade multiple related Kubernetes entities. Let's say we want to install any chart from the helm registry, we just need to type in the below command and helm will do the heavy lifting for us. $ helm install [RELEASE_NAME] [REPO]/[CHART] But below post is not about the basics of helm or how to install or upgrade a chart, etc. It's been a long time since I wrote anything, so I just thought to write something about what new I learned today :)  While installing one of my charts, I encountered below issue: Error: INSTALLATION FAILED: rendered manifests contain a resource that already exists. Unable to continue with install: StorageClass "demo-sc" in namespace "" exists and cannot be imported into the current release: invalid ownership metadata; label validation error: missing key "app.kubernetes.io/managed-by&qu
Read more

Configuration and setting-up of AIDE on RHEL6

AIDE is a powerful package for checking integrity of files on a machine/system. Prerequisites : Just aide package. [root@sunny ~]# yum install aide -y Loaded plugins: refresh-packagekit, rhnplugin This system is not registered with RHN.                                                                         RHN support will be disabled. Setting up Install Process Resolving Dependencies --> Running transaction check ---> Package aide.x86_64 0:0.14-3.el6 set to be updated --> Finished Dependency Resolution Dependencies Resolved ================================================================================  Package         Arch              Version               Repository        Size ================================================================================ Installing:  aide            x86_64            0.14-3.el6            local            123 k Transaction Summary =============================================================
Read more