Posts Tagged ‘putty’

Connect to Oracle Linux O/S without password !!

DISCLAIMER : Do not attempt this on critical or Production System.

I run multiple VirtualBox hosting Oracle Linux with Oracle database. It’s like a playground for me to do lot of oracle stuff.

Every time I have to take a connection , It’s painful to enter id/pwd for these so called playground system.

Started doing a little search as to how other fellow DBAs are getting away with this issue. Here is a little cheat trick that can be applied on non-critical systems.

Putty doesn’t give you an option to store password, but it does give you an option to store user name. Refer to below screenshot.


Assuming user ‘neeraj’ was already created in Oracle Linux O/S , let take a connection by specifying password


Let’s create a dir .ssh into /home/neeraj

Next challenge is how to avoid entering password everytime a connection is established to OL ( Oracle Linux ) via account ‘neeraj’

Here is a little cheat trick

Download Putty Keygen software from this url andopen the same. Keep settings as show below.


Click on generate button and randomly move mouse on blank area to generate a random key. Within a min, you would see similar to this


Click “Save Private Key button” and save Private key on local drive.

Note : If anyone get hold of this Private key, they can access your Virtual Machine running within VirtualBox without the need to enter id/pwd.

Next step is to open saved Private key ( C:\Misc_Things\test.ppk ) in notepad and copy the lines that represent PUBLIC key in clipboard


Since there are 3 lines , make sure to combine all line and create sort of single line which represents Public Key.

Since your putty session via ‘neeraj’ account is still active , go into following dir /home/neeraj/.ssh/

and create a file called authorized_keys and paste that 1 line which represents public key


Notice we have to insert ” ssh-rsa ” in front of our public key. There is a space in front and end of keyword ssh-rsa. Click on above screenshot to see a large image file

Now configure existing putty connection to use Private Key as shown below


Now take a fresh connection …. Voilla as seen in below screenshot , we dint had to enter pwd , it utilized Private/Public key and authenticated our dummy account ‘neeraj’



Running GUI via putty

April 24, 2013 3 comments

At times we have to invoke some sort of gui client ( let’s say Oracle Installer etc ) from putty. It can be a pain to have it started, but if things are configured properly it’s not that difficuilt.

For this exercise, we would require following software

1) Putty

A free open source based terminal emulator through which you can connect to your unix, linux box

You can download it from here for free


2) Xming X Server for Windows ( To be installed on local machine )

Again this is also based on open source , it’s a leading X Server for windows. You can download it from here for free

Configuring Xming Server

After you are done with Xming Server installation on your Win ( Win 7 in my case ) , we need to configure it by invoking Xlaunch from Xming Menu.

Here are some of the screenshots that shows you how to configure the Xming






Hit Save Configuration button & then Finish



Configuring Putty Client for Xming

Now we need to configure putty, assuming you already know your Unix/Linux Server hostname or ip address, here are the steps to configure Xming


Change the value for scrollback to a desired bigger no.


Make sure “Enabling X Forwarding is selected” with a value of localhost:0


Now go back to sessions option that appear on left and save this putty configuration

Now we just need to invoke Xming Server from Start Menu.

Go to Start Menu — > All Programs –>Xming —> Xming

This will bring Xming in taskbar next to windows clock


Take a connection through putty to your linux/Unix Server and after entering credentials type in xclock. It should come up like shown below



If you want to run xclock in the background, invoke following command

xclock &

instead of just


So far this works great, but what i observed was as soon as shifted to oracle user on unix it stopped working it gave me this error

[oracle@pr ~]$ xclock
Xlib: connection to “localhost:11.0” refused by server
Xlib: PuTTY X11 proxy: MIT-MAGIC-COOKIE-1 data did not match
Error: Can’t open display: localhost:11.0
[oracle@pr ~]$

For this there is a workaround, hift back to root account and issue following command

xauth list


You might see just 1 line depending upon how many keys are present in xauth. In my case there are 3 keys

Copy the last line into clipboard

pr.localhosts.localdomain/unix:11  MIT-MAGIC-COOKIE-1  51da8af273156d606b3080213fae200d


Switch to Oracle account via su – oracle

and issue following command

xauth add pr.localhosts.localdomain/unix:11  MIT-MAGIC-COOKIE-1  51da8af273156d606b3080213fae200d

Basically i added key to xauth

and now you are all set and you wont get this error atleast in current session





Categories: Uncategorized Tags: , , , , , , , ,