Tuesday, August 28, 2012

Receiving 'Access Denied' just after typing the username in Putty

Problem: Getting 'Access Denied' just after typing username in putty.

Information: The above problem occurs because of the failure of GSSAPI authentication.

What is GSSAPI?  
Generic Security Services Application Program Interface(GSSAPI) is a ITEF standard for doing strong encrypted authentication in network based applications. OPENssh uses this API and the underlying kerberos 5 code to provide a alternative means of authentication other than ssh_keys.
The GSSAPI, by itself, does not provide any security. Instead, security service vendors provide GSSAPI implementations usually in the form of libraries installed with their security software.


1. Open Putty.
2. Go to Connection->SSH->Auth->GSSAPI.
3. Uncheck the "Attempt GSSAPI authentication(SSH2-only)" option.
4. Save the session.

Putty: Access Denied Problem

Note: PuTTY 0.62 fixed the bug where failing GSSAPI authentication caused this error message.


Saturday, June 30, 2012

Ubuntu 12.04 : Middle Click Shortcut

Using Mouse:
1.  Usually Mouse has a scroll wheel, click it to use it as middle click.
2.  Some old mouse has middle click instead of scroll wheel.

Using Touch-pad:

1. On touchpads that support multi-finger taps, you can tap with three fingers at once to middle-click.
    Note: This feature is not available in all laptops. My laptop doesn't have this functionality.


1. "Paste Selected Text" inside applications. Select the text as normal, then bring your mouse(without deselecting) where you want to paste it, and finally use middle click to paste it. Some of the applications that I have tested till now are: gedit, chrome, terminal, gnote.
Note: Pasting text with your middle mouse button is completely separate from the normal clipboard. Selecting text does not copy it to your clipboard.

2. In the "file manager", middle-click serves two roles. If you middle-click a folder, it will open in a new tab. This mimics the behavior of popular web browsers. If you middle-click a file, it will open the file, just as if you had double-clicked.

3. Most "web browsers" allow you to open links in tabs quickly with the middle mouse button. Just click any link with your middle mouse button, and it will open in a new tab.

4. On "scrollbars and sliders", a regular click in the empty space moves by a set amount (such as one page) in the direction you clicked. You can also middle-click in the empty space to move to exactly the location you clicked.



Sunday, May 6, 2012

Recover Login Password of Ubuntu 12.04

After my first installation of Ubuntu 12.04, I forgot my login password and need to recover it.

To recover it you need to follow these steps:

1. Boot your computer.

2. When you get the grub menu, select option with recover as shown in figure.

Ubuntu 12.04 : Grub Menu
3. This will take you to recovery menu. In recovery menu select option "drop to root shell" as shown in figure.

Ubuntu 12.04 : Recovery Menu

4. A shell prompt will be displayed at the bottom of the screen with root as username. To change the password of particular user say naveen

       passwd naveen

5. The above command will ask you to enter your new password and retype password. Type your new password.

6. You might get "Authentication Manipulation error". If you get this error then you need to type :
     mount -rw -o remount /
    And again follow step 4 and 5.