Using Python and Shred to securely

remove directories and files on Linux File System

Platform OS:

Ubuntu 10.10

Programming Language:

Python -

Application:

Shred

Summary:

There was a need to find an automated means to safely clean up on my desktop using a file shredder application on a Linux platform. The application that I’ve chosen for this project was “Shred”. This application is available on most Linux distributions and since this application does not provide a switch to recursively remove all files and the parent directory. I have chose to quickly write a script to securely overwrite and remove the files in a directory location provided on a command line.

Shred Settings:

The shred application is capable of numerous settings, please see the man pages for a complete list of shred settings. On this particular project I have chosen the following settings to  erase files on my linux system:

shred -uvfzn7 <filename>

-u, --remove

              truncate and remove file after overwriting

 -v, --verbose

              show progress

 -f, --force

              change permissions to allow writing if necessary

 -z, --zero

              add a final overwrite with zeros to hide shredding

-n, --iterations=7

              overwrite N times instead of the default (3)

Python Script Usage: This program has been updated to account for spaced an special characters in file names

Step 1.

Save the script to the following file name- ShredFile.py -

Step 2.

Execute the following script from command line using the following command:

Step 3.

Enter a Directory path within your file system

Step 4.

Verify that you entered the correct directory and select Yes or No to re-enter the folder path.

Results:

You can enter another directory or enter Q to quit the application.

Python Script:

'''

Created on Aug 26, 2011

@author:

'''

import os  

emptyDirs = []

def removeDirectory(dirEntry):

    print ("Shredding files in " + dirEntry[0])

    deleteFiles(dirEntry[2],dirEntry[0])

    emptyDirs.insert(0, dirEntry[0])

def deleteFiles(dirList, dirPath):

    for file in dirList:

        try:

            print ("Shredding "  + (file))

            fileshred = dirPath + "/" +  file #This is the old name

            fileshred = "\"" + fileshred + "\""      

            os.system("shred -uvfzn7 " + fileshred)

        except: os.error

while True:    

    try:

        pathloc = raw_input('Enter a path for the directory to delete: or Q to Quit >>> ')

        path = str(pathloc)

        if path == "Q" or path == "q":

            print("Good Bye")

            break

        else:

            Verify= raw_input('Are you sure you want to delete %s Yes or No >>> ' % path)

            if Verify != "Yes":

                print("Please Enter Yes or No exactly")

                break

    except:

        break

    else:

        try:

            tree = os.walk(path)

        except: os.error

        print("unable to locate Directory -->> %s" % path)

        for directory in tree:

            removeDirectory(directory)

#Remove the empty directories

        for dir in emptyDirs:

                #dir = "\"" + dir + "\""

                #print ("Removing " + dir)

                print (dir)

                try:

                    os.rmdir(dir)

                except: os.error

emptyDirs = []