pycryptodome

from Crypto.Cipher import AES from Crypto.Random import get_random_bytes from Crypto.Protocol.KDF import PBKDF2 import os # Simulate a password for key derivation password = os.environ.get('CRYPTO_PASSWORD', 'mysecretpassword').encode('utf-8') # Generate a random salt salt = get_random_bytes(16) # Derive a strong key from the password and salt # Use default iterations (or a high number like 1000000) key = PBKDF2(password, salt, dkLen=32) # 32 bytes for AES-256 # The data to encrypt data = b"This is a super secret message." # Encrypt with AES GCM # A nonce is automatically generated by AES.new() in GCM mode cipher = AES.new(key, AES.MODE_GCM) ciphertext, tag = cipher.encrypt_and_digest(data) nonce = cipher.nonce print(f"Original: {data}") print(f"Salt: {salt.hex()}") print(f"Nonce: {nonce.hex()}") print(f"Ciphertext: {ciphertext.hex()}") print(f"Tag: {tag.hex()}") # --- Decryption --- # Re-derive the key using the same password and salt decryption_key = PBKDF2(password, salt, dkLen=32) # Create a new cipher object for decryption using the received key and nonce decrypt_cipher = AES.new(decryption_key, AES.MODE_GCM, nonce=nonce) # Decrypt and verify try: plaintext = decrypt_cipher.decrypt_and_verify(ciphertext, tag) print(f"Decrypted: {plaintext}") except ValueError: print("Decryption failed or message was tampered with!")