Remove Password From PDF – Unlock for FREE

If you have a PDF file protected by a password, you may wonder how to unlock it and remove the password protection so you don’t have to enter the password every time you want to open the file.

The PDF file protection can be easily removed by using a “Print” feature that is present in any web-browser on any operation system, incl. Windows, MacOS and Linux.

Below you will find an easy to follow step-by-step guide on how to unlock the password-protected PDF file using the web-browser’s “Print” feature. (more…)

HowTo: Create a Password Protected ZIP File in Linux

This is a small note that describes how to encrypt and decrypt a ZIP file from the Linux command line.

I’ll show how to create a password protected ZIP archive from one or several unprotected files or folders.

Warning! The standard ZIP encryption is very weak and could be cracked easily.

Password Protected ZIP File in Linux

Create an encrypted ZIP file secure.zip from some file:

$ zip --encrypt secure.zip file
Enter password: 
Verify password: 
  adding: file (deflated 8%)

Create password protected ZIP archive secure.zip from the several files:

$ zip --encrypt secure.zip file1 file2 file3
Enter password: 
Verify password: 
  adding: file1 (stored 15%)
  adding: file2 (deflated 30%)
  adding: file3 (deflated 45%)

Create an encrypted ZIP archive secure.zip from a folder /var/log/:

$ zip --encrypt -r secure.zip /var/log/
Enter password: 
Verify password: 
  adding: var/log/ (stored 0%)
  adding: var/log/dmesg.0 (deflated 74%)
  adding: var/log/dpkg.log.9.gz (deflated 0%)
  adding: var/log/samba/log.asc-nb (deflated 96%)
***

Use the following command to uncompress a ZIP file:

$ unzip secure.zip
Enter password:
***

Encrypt and Decrypt ZIP Archive in Linux

You were interactively prompted for the password in the examples above.

If you want to create a password protected ZIP file from some shell script, you may want to do it non-interactively.

This method is more insecure, as the password is entered as plain text.

You can easily encrypt and decrypt ZIP files from the Linux command line without being prompted for the password.

Do it as follows:

$ zip -P passw0rd secure.zip file
$ zip -P passw0rd secure.zip file1 file2 file3
$ zip -P passw0rd -r secure.zip /var/log/

Uncompress a password protected ZIP archive:

$ unzip -P passw0rd secure.zip

Generating Random Passwords in the Linux Command Line

You can use the following command to generate the random password:

$ tr -dc A-Za-z0-9 < /dev/urandom | head -c 8 | xargs

Sample output:

4fFUND1d

You can create a bash shell function as follows (add to your ~/.bashrc):

# Random password generator
genpasswd() {
tr -dc A-Za-z0-9 < /dev/urandom | head -c ${1:-8} | xargs
}

Reload .bashrc file.

$ . ~/.bashrc

Now use genpasswd to generate random passwords:

$ genpasswd
vmuWt7TS
$ genpasswd 10
ymkIgxcdCh
$ genpasswd 16
wQnqgdc5tAQoiBdf