encryptFile.py

def encrypt(dataFile, publicKeyFile):
    '''
    use EAX mode to allow detection of unauthorized modifications
    '''
    # read data from file
    with open(dataFile, 'rb') as f:
        data = f.read()
    
    # convert data to bytes
    data = bytes(data)

    # read public key from file
    with open(publicKeyFile, 'rb') as f:
        publicKey = f.read()
    
    # create public key object
    key = RSA.import_key(publicKey)
    sessionKey = os.urandom(16)

    # encrypt the session key with the public key
    cipher = PKCS1_OAEP.new(key)
    encryptedSessionKey = cipher.encrypt(sessionKey)

    # encrypt the data with the session key
    cipher = AES.new(sessionKey, AES.MODE_EAX)
    ciphertext, tag = cipher.encrypt_and_digest(data)
    []

    # save the encrypted data to file
    [ fileName, fileExtension ] = dataFile.split('.')
    encryptedFile = fileName + '_encrypted.' + fileExtension
    with open(encryptedFile, 'wb') as f:
        [ f.write(x) for x in (encryptedSessionKey, cipher.nonce, tag, ciphertext) ]
    print('Encrypted file saved to ' + encryptedFile)