How to Recover an Encrypted Home Directory on Ubuntu

While the home-folder encryption in Ubuntu is far from a perfect solution (there is considerable data leakage from the swap file and the temp directory - for example once I've observed the flash videos from Chromium porn private browsing mode being present in the /tmp directory), it is a partial solution nevertheless and very easy to set up during installation. However what can you do if you need to recover the data because you dismantled your system?

Credit where credit is due: this guide is taken mostly from the Ubuntu wiki page. Also, this is not an easy "one-click" process. You should proceed carefully, especially if you don't have much experience with the command line.

Start Ubuntu (from a separate install, from the LiveCD, etc) and mount the source filesystem (this is usually as simple as going to the Places menu and selecting the partition). Start a terminal (Alt+F2 -> gnome-terminal) and navigate to the partitions home directory. Usually this will look like the following:

cd /media/9e6325c9-1140-44b7-9d8e-614599b27e05/home/

Now navigate to the users ecryptfs directory (things to note: it is ecryptfs not encryptfs and your username does not coincide with your full name - the one you click on when you log in)

cd .ecryptfs/username

The next step is to recovery your "mount password" which is different from the password you use to log in (when it asks you, type in the login password used for this account - for which you are trying to recover the data). Take note of the returned password (you can copy it by selecting it and pressing Shift+Ctrl+C if you are using the Gnome Terminal)

ecryptfs-unwrap-passphrase .ecryptfs/wrapped-passphrase

Now create a directory where you would like to mount the decrypted home directory:

sudo mkdir /media/decrypted

Execute the following and type in (or better - copy-paste) the mount password you've recovered earlier

sudo ecryptfs-add-passphrase --fnek

It will return something like the following. Take note of the second key (auth tok):

Inserted auth tok with sig [9986ad986f986af7] into the user session keyring 
Inserted auth tok with sig [76a9f69af69a86fa] into the user session keyring

Now you are ready to mount the directry:

sudo mount -t ecryptfs /media/9e6325c9-1140-44b7-9d8e-614599b27e05/home/.ecryptfs/username/.Private /media/decrypted
 Passphrase:  # mount passphrase
 Selection: aes
 Selection: 16
 Enable plaintext passthrough: n 
 Enable filename encryption: y # this is not the default!
 Filename Encryption Key (FNEK) Signature: # the second key (auth tok) noted

You will probably get a warning about this key not being seen before (you can type yes) and asking if it should be added to your key cache (you should type no, since you won't be using it again probably).

That's it, now (assuming everything went right) you can access your decrypted folder in /media/decrypted. The biggest gotcha is that home/username/.Private is in fact a symlink, which - if you have an other partition mounted - will point you to the wrong directory, so you should use the home/.ecryptfs/username directory directly... If this does work you try this from this ubuntu tutorial ...

Or you can also try this Live CD method of opening a encrypted home directory

How to remove icons from Top-Taskbar on Gnome

You are using the Gnome-Classic interface - either you are using this by choice, or you are using the fallback  mode which occurs if your graphics card & driver doesnt the 3D Acceleration required for the full Gnome-Shell GUI.

To add and remove application launchers in the gnome-panel you need to:

Press Win+Alt and right-click the top menu bar - N.B. Win is the Windows Symbol key

If you are not using Compiz then you need to :

Press Alt and right-click the top menu bar

Much more information is described in the linked Q&A and other links in that answer.

All You Need To Know About Linux Commands

System Info

date – Show the current date and time

cal – Show this month's calendar

uptime – Show current uptime

w – Display who is online

whoami – Who you are logged in as

finger user – Display information about user

uname -a – Show kernel information

cat /proc/cpuinfo – CPU information

cat /proc/meminfo – Memory information

df – Show disk usage

du – Show directory space usage

free – Show memory and swap usage

Keyboard Shortcuts

Enter – Run the command

Up Arrow – Show the previous command

Ctrl + R – Allows you to type a part of the command you're looking for and finds it

Ctrl + Z – Stops the current command, resume with fg in the foreground or bg in the background

Ctrl + C – Halts the current command, cancel the current operation and/or start with a fresh new line

Ctrl + L – Clear the screen

command | less – Allows the scrolling of the bash command window using Shift + Up Arrow and Shift + Down Arrow

!! – Repeats the last command

command  !$ – Repeats the last argument of the previous command

Esc + . (a period) – Insert the last argument of the previous command on the fly, which enables you to edit it before executing the command

Ctrl + A – Return to the start of the command you're typing

Ctrl + E – Go to the end of the command you're typing

Ctrl + U – Cut everything before the cursor to a special clipboard, erases the whole line

Ctrl + K – Cut everything after the cursor to a special clipboard

Ctrl + Y – Paste from the special clipboard that Ctrl + U and Ctrl + K save their data to

Ctrl + T – Swap the two characters before the cursor (you can actually use this to transport a character from the left to the right, try it!)

Ctrl + W – Delete the word / argument left of the cursor in the current line

Ctrl + D – Log out of current session, similar to exit

Learn the Commands

apropos subject – List manual pages for subject

man -k keyword – Display man pages containing keyword

man command – Show the manual for command

man -t man | ps2pdf - > man.pdf  – Make a pdf of a manual page

which command – Show full path name of command

time command – See how long a command takes

whereis app – Show possible locations of app

which app – Show which app will be run by default; it shows the full path

Searching

grep pattern files – Search for pattern in files

grep -r pattern dir – Search recursively for pattern in dir

command | grep pattern – Search for pattern in the output of command

locate file – Find all instances of file

find / -name filename – Starting with the root directory, look for the file called filename

find / -name ”*filename*” – Starting with the root directory, look for the file containing the string 

filename

locate filename – Find a file called filename using the locate command; this assumes you have already used the command updatedb (see next)

updatedb – Create or update the database of files on all file systems attached to the Linux root directory

which filename – Show the subdirectory containing the executable file  called filename

grep TextStringToFind /dir – Starting with the directory called dir, look for and list all files containing TextStringToFind

File Permissions

chmod octal file – Change the permissions of file to octal, which can be found separately for user, group, and world by adding: 4 – read (r), 2 – write (w), 1 – execute (x)

Examples:

chmod 777 – read, write, execute for all

chmod 755 – rwx for owner, rx for group and world

For more options, see man chmod.

File Commands

ls – Directory listing

ls -l – List files in current directory using long format

ls -laC – List all files in current directory in long format and display in columns

ls -F – List files in current directory and indicate the file type

ls -al – Formatted listing with hidden files

cd dir – Change directory to dir

cd – Change to home

mkdir dir – Create a directory dir

pwd – Show current directory

rm name – Remove a file or directory called name

rm -r dir – Delete directory dir

rm -f file – Force remove file

rm -rf dir – Force remove an entire directory dir and all it’s included files and subdirectories (use with extreme caution)

cp file1 file2 – Copy file1 to file2

cp -r dir1 dir2 – Copy dir1 to dir2; create dir2 if it doesn't exist

cp file /home/dirname – Copy the file called filename to the /home/dirname directory

mv file /home/dirname – Move the file called filename to the /home/dirname directory

mv file1 file2 – Rename or move file1 to file2; if file2 is an existing directory, moves file1 into directory file2

ln -s file link – Create symbolic link link to file

touch file – Create or update file

cat > file – Places standard input into file

cat file – Display the file called file

more file – Display the file called file one page at a time, proceed to next page using the spacebar

head file – Output the first 10 lines of file

head -20 file – Display the first 20 lines of the file called file

tail file – Output the last 10 lines of file

tail -20 file – Display the last 20 lines of the file called file

tail -f file – Output the contents of file as it grows, starting with the last 10 lines

Compression

tar cf file.tar files – Create a tar named file.tar containing files

tar xf file.tar – Extract the files from file.tar

tar czf file.tar.gz files – Create a tar with Gzip compression

tar xzf file.tar.gz – Extract a tar using Gzip

tar cjf file.tar.bz2 – Create a tar with Bzip2 compression

tar xjf file.tar.bz2 – Extract a tar using Bzip2

gzip file – Compresses file and renames it to file.gz

gzip -d file.gz – Decompresses file.gz back to file

Printing

/etc/rc.d/init.d/lpd start – Start the print daemon

/etc/rc.d/init.d/lpd stop – Stop the print daemon

/etc/rc.d/init.d/lpd status – Display status of the print daemon

lpq – Display jobs in print queue

lprm – Remove jobs from queue

lpr – Print a file

lpc – Printer control tool

man subject | lpr – Print the manual page called subject as plain text

man -t subject | lpr – Print the manual page called subject as Postscript output

printtool – Start X printer setup interface

Network

ifconfig – List IP addresses for all devices on the local machine

ping host – Ping host and output results

whois domain – Get whois information for domain

dig domain – Get DNS information for domain

dig -x host – Reverse lookup host

wget file – Download file

wget -c file – Continue a stopped download

SSH

ssh user@host – Connect to host as user

ssh -p port user@host – Connect to host on port port as user

ssh-copy-id user@host – Add your key to host for user to enable a keyed or passwordless login

User Administration

adduser accountname – Create a new user call accountname

passwd accountname – Give accountname a new password

su – Log in as superuser from current login

exit – Stop being superuser and revert to normal user

Process Management

ps – Display your currently active processes

top – Display all running processes

kill pid – Kill process id pid

killall proc – Kill all processes named proc (use with extreme caution)

bg – Lists stopped or background jobs; resume a stopped job in the background

fg – Brings the most recent job to foreground

fg n – Brings job n to the foreground

Installation from source

./configure

make

make install

dpkg -i pkg.deb – install a DEB package (Debian / Ubuntu / Linux Mint)

rpm -Uvh pkg.rpm – install a RPM package (Red Hat / Fedora)

Stopping & Starting

shutdown -h now – Shutdown the system now and do not reboot

halt – Stop all processes - same as above

shutdown -r 5 – Shutdown the system in 5 minutes and reboot

shutdown -r now – Shutdown the system now and reboot

reboot – Stop all processes and then reboot - same as above

startx – Start the X system

Recommended reading:

Cheat-Sheets.org – All cheat sheets, round-ups, quick reference cards, quick reference guides and quick reference sheets in one page. The only one you need.

Tutorial: The best tips & tricks for bash, explained – Linux Tutorial Blog / Quality Linux tutorials without clutter

LinuxCommand.org – Learning the shell, Writing shell scripts, Script library, SuperMan pages, Who, What, Where, Why

LinuxManPages.com – General commands, System calls, Subroutines, Special files, File formats, Games, Macros and conventions, Maintenence commands, Most Popular Man Pages

Linux Newbie Guide: Shorcuts and Commands - Linux essential shortcuts and sanity commands; Common Linux commands - system info; Basic operations, network apps, file (de)compression; Process control; Basic administration commands, accessing drives/partitions; Network administration tools, music-related commands, graphics-related commands.

How the Internet Works ..Explained Here

Got files separed from norm HTML

After meet up with team members we decide to migrate the site from norm HTML to PHP, the all projetc will take quite a while to finish, but so far the foundations, of the project are already laid down.. Quite interesting to see how this process is unfolding down ...

• Cut all the code and past in a separated document
• Save the new document with a different header name with .php file extension.
• Then import the content of the heading document into the main html document using the include* function - [ include is part of php library ]

Seems like all gone as we were expecting, but bear in mind that we faced some bugs when we tried to apply this approach the first time  ... Here it goes the output still getting the original content but keeping all the information rendered on server..

Here follows a screen shoot of the file the way it was before it been changed .. All the HTML markup in just one page ..

Happy New Year To All

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Using Virtual Ethernet Adapters in Promiscuous Mode on a Linux Host

VMware Workstation does not allow the virtual Ethernet adapter to go into promiscuous mode unless the user running VMware Workstation has permission to make that setting. This follows the standard Linux practice that only root can put a network interface into promiscuous mode.

When you install and configure VMware Workstation, you must run the installation as root. VMware Workstation creates the VMnet devices with root ownership and root group ownership, which means that only root has read and write permissions to the devices.

To set the virtual machine's Ethernet adapter to promiscuous mode, you must launch VMware Workstation as root because you must have read and write access to the VMnet device. For example, if you are using bridged networking, you must have access to /dev/vmnet0.

To grant selected other users read and write access to the VMnet device, you can create a new group, add the appropriate users to the group and grant that group read and write access to the appropriate device. You must make these changes on the host operating system as root (su -). For example, you can enter the following commands:

chgrp <newgroup> /dev/vmnet0

chmod g+rw /dev/vmnet0

<newgroup> is the group that should have the ability to set vmnet0 to promiscuous mode.

The command to run vmware workstations ads root is simple: user@user#:~$ sudo vmware start

If you want all users to be able to set the virtual Ethernet adapter (/dev/vmnet0 in our example) to promiscuous mode, run the following command on the host operating system as root:

chmod a+rw /dev/vmnet0

This is another posting showing "how to do computing" for everyday computer usages... For a general public