File Encrypt/Decrypt Program

This is a C++ program that encrypts or decrypts all files in a given directory using a Caesar cipher. The key for encryption/decryption comes from a .env file. It uses shared memory and semaphores to process files in parallel with forked processes. There's also a Python script to create test files for trying it out.

What It Does

• Encrypts or decrypts files in a directory using a key from .env.
• Uses a simple Caesar cipher (shifts characters by the key value).
• Processes files concurrently with shared memory and semaphores.
• Includes a Python script (makeDirs.py) to generate random test files.

Requirements

• C++ Compiler: Needs g++ with C++17 support.
• Python: Python 3.x for the makeDirs.py script.
• OS: Works on Linux/macOS (uses POSIX semaphores and shared memory).
• Libraries: Just standard C++ libraries (like <filesystem>, <fstream>).

Setup

1. Clone the repo:

   git clone https://github.com/abhinav-1504/EncryptX-CPP.git
   cd EncryptX-CPP
   

2. Make sure you have a .env file in the root with a single number (like 8717) as the key.

3. Build the programs (creates encrypt_decrypt and cryption):

   make
   

How to Use

1. Create Test Files (Optional):

   Run the Python script to make a test directory with 10 random text files:

   python3 makeDirs.py
   

2. Run the Program:

   Start the main program:

   ./encrypt_decrypt

   • Enter the directory path (e.g., test).
   • Type encrypt or decrypt for the action.

3. What Happens:

   • The program reads the key from .env and applies the Caesar cipher to each file.
   • It logs start and end times for each file's processing.
   • If a file or directory can't be opened, it shows an error.

File Structure

::

.
├── .env                    # Holds the encryption key (e.g., 8717)
├── Makefile                # Compiles the C++ programs
├── makeDirs.py             # Python script for test files
├── main.cpp                # Main program for user input and file processing
├── src/
│   ├── app/
│   │   ├── encryptDecrypt/
│   │   │   ├── Cryption.cpp    # Core encryption/decryption code
│   │   │   ├── Cryption.hpp    # Header for encryption functions
│   │   │   ├── CryptionMain.cpp # Standalone encryption program
│   │   ├── fileHandling/
│   │   │   ├── IO.cpp          # Handles file streams
│   │   │   ├── IO.hpp          # Header for file I/O
│   │   │   ├── ReadEnv.cpp     # Reads the .env key
│   │   ├── processes/
│   │   │   ├── ProcessManagement.cpp # Manages task queue and forks
│   │   │   ├── ProcessManagement.hpp # Header for process management
│   │   │   ├── Task.hpp        # Defines tasks for encrypt/decrypt

How It Works

• Main Program (encrypt_decrypt):

  • Asks for a directory and action (encrypt/decrypt).
  • Scans the directory and creates a Task for each file.
  • Sends tasks to a queue in ProcessManagement, which forks processes to handle them.

• Encryption/Decryption (Cryption.cpp):

  • Reads the key from .env via ReadEnv class.
  • Shifts file characters forward (encrypt) or backward (decrypt) by the key.
  • Uses binary mode for file operations.

• Process Management:

  • Uses shared memory to store up to 1000 tasks.
  • Semaphores (itemsSemaphore, emptySlotsSemaphore) ensure safe queue access.
  • Forks a process per task to run executeCryption.

• File Handling:

  • IO class opens and manages file streams.
  • ReadEnv reads the key from .env.

• Test Files:

  • makeDirs.py creates 10 text files with 1000 random characters each in a test folder.

Notes

• The .env key must be a number, or the program might crash.
• Files must be readable/writable in binary mode.
• Needs POSIX support (shm_open, sem_open) for shared memory and semaphores.
• The cryption program is used internally for processing tasks from the queue.

Cleanup

Remove compiled files:

make clean

License

No license. Feel free to use or modify it.