chacha20poly1305-reuseable

import os from chacha20poly1305_reuseable import ChaCha20Poly1305Reusable # In a real application, securely load your key (32 bytes). # For demonstration, a random key is generated. key = os.urandom(32) # Associated data (AAD) is optional, but recommended for integrity checks. associated_data = b"Config data, not encrypted but authenticated." plaintext = b"This is the secret message to be encrypted." # Initialize the cipher object with the key cipher = ChaCha20Poly1305Reusable(key) # Encrypt the plaintext # The nonce is generated internally and returned, must be unique per encryption. nonce, ciphertext, tag = cipher.encrypt(plaintext, associated_data) print(f"Encryption successful:") print(f" Nonce: {nonce.hex()}") print(f" Ciphertext: {ciphertext.hex()}") print(f" Tag: {tag.hex()}") # Decrypt the ciphertext try: decrypted_text = cipher.decrypt(nonce, ciphertext, tag, associated_data) print(f"Decryption successful: {decrypted_text.decode()}") assert decrypted_text == plaintext print("Message integrity verified.") except Exception as e: print(f"Decryption failed: {e}") # The 'cipher' object can be reused for subsequent encryptions/decryptions # with a *new*, unique nonce for each operation. new_plaintext = b"Another secret message, secured by the same key." new_nonce, new_ciphertext, new_tag = cipher.encrypt(new_plaintext, associated_data) print(f"\nReused cipher for new encryption (new nonce): {new_nonce.hex()}")