7iGknQQQ

1    private static SecretKey generateSessionKey() throws NoSuchAlgorithmException{
2        KeyGenerator generator = KeyGenerator.getInstance("AES");
3        return generator.generateKey();
4    }
5
6    private static byte[] encryptSessionKey(SecretKey sessionKey, Key publicKey) throws NoSuchAlgorithmException, InvalidKeyException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException{
7        Cipher cipher = Cipher.getInstance("RSA");
8        cipher.init(Cipher.ENCRYPT_MODE, publicKey);
9        byte[] encodedKey = cipher.doFinal(sessionKey.getEncoded());
10        return Base64.getEncoder().encode(encodedKey);
11    }
12
13    private static SecretKey decryptSessionKey(byte[] base64EncodedKey, Key privateKey) throws NoSuchAlgorithmException, InvalidKeyException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException{
14
15        Cipher cipher = Cipher.getInstance("RSA");
16        cipher.init(Cipher.DECRYPT_MODE, privateKey);
17        byte[] decodedKey = cipher.doFinal(Base64.getDecoder().decode(base64EncodedKey));
18        return new SecretKeySpec(decodedKey, 0, decodedKey.length, "AES");
19    }
20    public static