===========================================================
                    K2L Encryption Tool
===========================================================

Author: K0NxT3D 
Script: k2l.sh 
Purpose: 
    This script encrypts a folder of Target_Dir using a 
    randomly generated ultra-high-entropy password, then 
    embeds the encrypted payload inside a PNG image. 

For Operational Use: 
    Edit k2l.sh and replace "Target_Dir" with the name or path 
    of the directory you want to encrypt. 

    The final output is a PNG file that contains hidden data 
    (ZIP + AES-256-CBC encrypted content) appended to the image.

===========================================================
                      HOW IT WORKS
===========================================================

1. A 1024-bit (128-byte) random password is generated using:
       openssl rand -hex 128

   The password is saved to:
       password.txt
   (Permissions are restricted to the current user only.)

2. A working folder named "Encrypted_Files" is created.

3. The folder:
       ./Target_Dir/
   is zipped with the random password and saved as:
       Encrypted_Files.zip

4. The ZIP file is encrypted using OpenSSL AES-256-CBC with:
       - PBKDF2 key derivation
       - 20,000 iterations
       - Base64 output encoding

   The result is saved as:
       Encrypted_Files/Encrypted_Files.k2l

5. All encrypted output files inside Encrypted_Files/ are 
   zipped together into:
       payload.zip

6. This ZIP is appended to a PNG image:
       logo.png  + payload.zip  → k2l.png

   The resulting PNG appears completely normal but contains 
   the encrypted payload attached to the end of the file.

7. The final stego PNG is placed inside the:
       Output/
   directory.

8. All temporary working files and folders are removed.

===========================================================
                   FILES AND FOLDERS
===========================================================

Target_Dir/           Folder containing files to encrypt 
Encrypted_Files/      Temporary working folder 
Encrypted_Files.zip   Protected ZIP (deleted after encryption) 
payload.zip           ZIP containing final encrypted content 
password.txt          Generated ultra-high-entropy password 
logo.png              Input container image 
k2l.png               Final image containing hidden payload 
Output/               Final destination for encoded image 
k2l.sh                Main script 
d2l.sh                Decryption script (included in distributable) 

===========================================================
                  REQUIREMENTS (DEPENDENCIES)
===========================================================

The script requires:

1. Bash shell 
2. zip (command-line tool) 
3. OpenSSL (with AES-256-CBC support) 
4. A PNG file named "logo.png" 
5. A folder named "Target_Dir/" containing files to secure 

Without these, the script will fail or skip certain steps.

===========================================================
                      USAGE INSTRUCTIONS
===========================================================

1. Place files you want encrypted inside:
       ./Target_Dir/

2. Make the script executable:
       chmod +x k2l.sh

3. Run the script:
       ./k2l.sh

4. When finished, retrieve the final output from:
       ./Output/k2l.png

5. The encryption password is stored in:
       password.txt
   KEEP THIS FILE SAFE! You cannot decrypt the payload without it.

===========================================================
                        IMPORTANT
===========================================================

• The password generated is ULTRA-HIGH ENTROPY 
  (256 hex characters, ~1024 bits). It cannot be guessed or brute-forced.

• Do NOT lose the file:
       password.txt

• The image created is NOT visually altered. The hidden 
  content is appended to the end of the PNG file.

• The script removes temporary files when finished.

• The script will fail if "Target_Dir/" is empty or missing.

===========================================================
                        DECRYPTION
===========================================================

The distributable includes the decryption script: 
   d2l.sh 

To reverse the process:

1. Ensure the following files are present in the same folder:
       - k2l.png
       - password.txt
       - d2l.sh

2. Make the decryption script executable:
       chmod +x d2l.sh

3. Run the decryption script:
       ./d2l.sh

4. The script will:
       - Extract the appended payload.zip from k2l.png
       - Restore the original folder structure
       - Place all decrypted files inside:
           ./Restored_Files/

5. Once complete, check ./Restored_Files/ to retrieve your original data. 

===========================================================
                        END OF FILE
===========================================================