AES-256 Encryption Wrapper for OpenSSL

This Wrapper/Library provides AES-256 encryption and decryption functions using GCM and CTR modes. It leverages OpenSSL for cryptographic operations and is designed to be fast and efficient.

Features

• AES-256-GCM Encryption and Decryption
• AES-256-CTR Encryption and Decryption
• Easy-to-use C API
• Python bindings for testing

Requirements

• OpenSSL library
• C compiler (e.g., GCC)
• Python 3.x
• ctypes module in Python

Files

• aes256.c: C implementation of AES-256 encryption and decryption functions.
• aes256.h: Header file for AES-256 functions.
• Makefile: Makefile for building the shared library.
• test_aes256.py: Python script for testing the AES-256 functions.

Installation

1. Clone the repository:

   git clone <repository-url>
   cd <repository-directory>

2. Build the shared library:

   make

   This will compile aes256.c and create the libaes256.so shared library.

Usage

C Library

Include the header file and link against the compiled shared library in your C project:

1. Include the header:

   #include "aes256.h"

2. Example usage:

   AES256_CTX ctx;
   uint8_t key[AES256_KEY_SIZE] = { ... }; // 32 bytes
   uint8_t iv[AES256_IV_SIZE] = { ... }; // 12 bytes for GCM
   uint8_t plaintext[] = "Hello, World!";
   uint8_t ciphertext[sizeof(plaintext)];
   uint8_t tag[AES256_TAG_SIZE]; // 16 bytes for GCM
   
   // Initialize context
   aes256_init(&ctx, key, iv);
   
   // Encrypt
   aes256_gcm_encrypt(&ctx, plaintext, sizeof(plaintext), NULL, 0, ciphertext, tag);
   
   // Decrypt
   uint8_t decrypted[sizeof(plaintext)];
   aes256_gcm_decrypt(&ctx, ciphertext, sizeof(ciphertext), NULL, 0, tag, decrypted);

Python

The test_aes256.py script demonstrates how to use the shared library from Python using the ctypes module.

1. Ensure the shared library is in the same directory as the Python script or in a directory included in your LD_LIBRARY_PATH.

2. Run the Python test script:

   python3 test_aes256.py

   This script tests both AES-256-GCM and AES-256-CTR encryption and decryption functions and prints the results.

Python Test Script

The test_aes256.py script tests the AES-256 encryption and decryption functions.