9ZbdHQGh

1public class DecipherDES_ex3 {
2    public static void main(String[] args) throws IOException, NoSuchPaddingException, NoSuchAlgorithmException, BadPaddingException, IllegalBlockSizeException, InvalidKeyException, InvalidKeySpecException {
3        // ir buscar a chave e verificar se bate certo com o ficheiro
4        String everything = "";
5        try(BufferedReader br = new BufferedReader(new FileReader("chave.txt"))) {
6            StringBuilder sb = new StringBuilder();
7            String line = br.readLine();
8            while (line != null) {
9                sb.append(line);
10                sb.append(System.lineSeparator());
11                line = br.readLine();
12            }
13            everything = sb.toString();
14        }
15
16        // decode the base64 encoded string
17        BASE64Decoder decoder = new BASE64Decoder();
18        byte[] decodedKey = decoder.decodeBuffer(everything);
19        // rebuild key using SecretKeySpec
20        SecretKey originalKey = new SecretKeySpec(decodedKey, 0, decodedKey.length, "DES");
21        System.out.println("CHAVE");
22        System.out.println(Base64.getEncoder().encodeToString(originalKey.getEncoded()));
23
24
25
26    }
27}