Java: Crypto Bad Padding Exceptions - netbeans

Question

I really need some help. I am working on this assignment in school. I'm supposed to read a txt file into a list or string, and Encrypt that list of string, save it and Decrypt it back into a list of string. I was able to Encrypt it and save it, but when I try to Decrypt it back,
it give me an error message about Bad Padding.
I really don't how to fix this problem. Any help will be really good.
import java.awt.FileDialog;
import java.awt.Frame;
import java.io.*;
import java.nio.file.*;
import java.security.*;
import java.util.*;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
public class WordAnalysisMenu {
private static KeyGenerator kgen;
private static SecretKey key;
private static byte[] iv = null;
static Scanner sc = new Scanner(System.in);
private static void init(){
try {
kgen = KeyGenerator.getInstance("AES");
kgen.init(128);
key = kgen.generateKey();
} catch (NoSuchAlgorithmException e) {
}
}
public static void main (String [] arge) throws NoSuchAlgorithmException, NoSuchPaddingException,
InvalidKeyException, IOException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException {
List<String> warPeace = new ArrayList<>();
while(true) {
int choice = menu();
switch(choice) {
case 0:
break;
case 1:
//select file for reading
warPeace = readFile();
break;
case 7:
//apply the cipher and save it to a file
init();
Frame frame = new Frame();
FileDialog fileDialog = new FileDialog(frame, "", FileDialog.SAVE);
fileDialog.setVisible(true);
Path path = Paths.get(fileDialog.getDirectory() + fileDialog.getFile());
iv = ListEncrypter(warPeace, path, key);
break;
case 8:
// read the ciper file, decode, and print
init();
frame = new Frame();
fileDialog = new FileDialog(frame, "", FileDialog.LOAD);
fileDialog.setVisible(true);
Path inputFile = Paths.get(fileDialog.getDirectory() + fileDialog.getFile());
warPeace = ListDecrypter(inputFile, key, iv);
break;
case 9:
System.out.println("Good bye!");
System.exit(0);
break;
default:
break;
}
}
}
public static int menu() {
int choice = 0;
System.out.println("\nPlease make a selection: ");
System.out.println("1.\t Select a file for reading.");
System.out.println("7.\t Apply cipher & save");
System.out.println("8.\t Read encoded file");
System.out.println("9.\t Exit");
Scanner scan = new Scanner(System.in);
try {
choice = scan.nextInt();
scan.nextLine();
}
catch(InputMismatchException ime) {
System.out.println("Invalid input!");
}
return choice;
}
public static List<String> readFile() {
List<String> word = new ArrayList<String>();
Frame f = new Frame();
FileDialog saveBox = new FileDialog(f, "Reading text file", FileDialog.LOAD);
saveBox.setVisible(true);
String insName = saveBox.getFile();
String fileSavePlace = saveBox.getDirectory();
File inFile = new File(fileSavePlace + insName);
BufferedReader in = null;
try {
in = new BufferedReader(new FileReader(inFile));
String line;
while (((line = in.readLine()) != null)) {
System.out.println(line);
String s = new String();
word.add(line);
}
} catch (IOException io) {
System.out.println("There Was An Error Reading The File");
} finally {
try {
in.close();
} catch (Exception e) {
e.getMessage();
}
}
return word;
}
private static byte[] ListEncrypter(List<String> content, Path outputFile, SecretKey key)
throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IOException, IllegalBlockSizeException, BadPaddingException {
Cipher encryptCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
//Cipher encryptCipher = Cipher.getInstance("AES/CFB8/NoPadding");
encryptCipher.init(Cipher.ENCRYPT_MODE, key);
StringBuilder sb = new StringBuilder();
content.stream().forEach(e -> sb.append(e).append(System.lineSeparator()));
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
CipherOutputStream cipherOutputStream = new CipherOutputStream(outputStream, encryptCipher);
cipherOutputStream.write(encryptCipher.doFinal(sb.toString().getBytes()));
//cipherOutputStream.write(sb.toString().getBytes());
cipherOutputStream.flush();
cipherOutputStream.close();
ByteArrayInputStream inputStream = new ByteArrayInputStream(outputStream.toByteArray());
Files.copy(inputStream, outputFile, StandardCopyOption.REPLACE_EXISTING);
return encryptCipher.getIV();
}
private static List<String> ListDecrypter(Path inputFile, SecretKey key, byte[] iv) throws
NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException,
InvalidAlgorithmParameterException, IOException, IllegalBlockSizeException, BadPaddingException {
Cipher decryptCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
//Cipher decryptCipher = Cipher.getInstance("AES/CBC/CFB8NoPadding");
IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);
decryptCipher.init(Cipher.DECRYPT_MODE, key, ivParameterSpec);
List<String> fileContent = new ArrayList<>();
String line = null;
ByteArrayInputStream inputStream = new ByteArrayInputStream(Files.readAllBytes(inputFile));
try(CipherInputStream chipherInputStream = new CipherInputStream(new FileInputStream(inputFile.toFile()), decryptCipher);
BufferedReader br = new BufferedReader(new InputStreamReader(chipherInputStream))) {
while ((line = br.readLine()) != null) {
System.out.println(line);
//fileContent.add(line);
}
}
return null;
}
}
This is the error message.
thread "main" java.io.IOException: javax.crypto.BadPaddingException:
Given final block not properly padded at
javax.crypto.CipherInputStream.getMoreData(CipherInputStream.java:121)
at javax.crypto.CipherInputStream.read(CipherInputStream.java:239)