Question

I want to encrypt a text file using AES encryption.
However,I am not so sure how to combine the Aes codes and the file reading code. I am new to this kind of encryption. Any help is appreciated.

I have tried to do this. And there is error under the encrypt and it state not applicable for the arguments. Or I should do it in another way?

public static void main(String[] args) throws Exception {

    FileReader file = new FileReader ("original.txt");
    BufferedReader reader = new BufferedReader(file);

    String text = "";
    String line = reader.readLine();
    while(line !=null)
    {
        text +=line; 
        line = reader.readLine();
    }


    String test = Testing.encrypt(text);
    System.out.println("Encrypted : " + test);
    reader.close();
  } 

The full codes is below. Thank you very much.

(AES encryption)

 package encypt.com;

import java.io.BufferedReader;
import java.io.FileReader;
import java.security.*;
import java.security.spec.InvalidKeySpecException;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import sun.misc.*;

public class Testing {

private static final String ALGORITHM = "AES";
private static final int ITERATIONS = 2;
private static final byte[] keyValue = 
    new byte[] { 'T', 'h', 'i', 's', 'I', 's', 'A', 'S', 'e', 'c', 'r', 'e', 't', 'K', 'e', 'y'};

public static String encrypt(String value, String salt) throws Exception {
    Key key = generateKey();
    Cipher c = Cipher.getInstance(ALGORITHM);  
    c.init(Cipher.ENCRYPT_MODE, key);

    String valueToEnc = null;
    String eValue = value;
    for (int i = 0; i < ITERATIONS; i++) {
        valueToEnc = salt + eValue;
        byte[] encValue = c.doFinal(valueToEnc.getBytes());
        eValue = new BASE64Encoder().encode(encValue);
    }
    return eValue;
}

public static String decrypt(String value, String salt) throws Exception {
    Key key = generateKey();
    Cipher c = Cipher.getInstance(ALGORITHM);
    c.init(Cipher.DECRYPT_MODE, key);

    String dValue = null;
    String valueToDecrypt = value;
    for (int i = 0; i < ITERATIONS; i++) {
        byte[] decordedValue = new BASE64Decoder().decodeBuffer(valueToDecrypt);
        byte[] decValue = c.doFinal(decordedValue);
        dValue = new String(decValue).substring(salt.length());
        valueToDecrypt = dValue;
    }
    return dValue;
}

private static Key generateKey() throws Exception {
    Key key = new SecretKeySpec(keyValue, ALGORITHM);
    // SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(ALGORITHM);
    // key = keyFactory.generateSecret(new DESKeySpec(keyValue));
    return key;
}


public static void main(String[] args) throws Exception {


    String password = "mypassword";
    String salt = "this is a simple clear salt";
    String passwordEnc = Testing.encrypt(password, salt);
    String passwordDec = Testing.decrypt(passwordEnc, salt);

   System.out.println("Salt Text : " + salt);
   System.out.println("Plain Text : " + password);
   System.out.println("Encrypted : " + passwordEnc);
   System.out.println("Decrypted : " + passwordDec);
}
}

(File reading code)

package encypt.com;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.util.Scanner;

public class readfile {
public static void main(String[] args) throws Exception {

    FileReader file = new FileReader ("key.txt");
    BufferedReader reader = new BufferedReader(file);

    String text = "";
    String line = reader.readLine();
    while(line !=null)
    {
        text +=line; 
        line = reader.readLine();
    }

    reader.close();
    System.out.println(text); 
  } 
} 

Answer 1

I guess your error occurs because you try to call

public static String encrypt(String value, String salt)

with

String test = Testing.encrypt(text);

so the salt parameter is missing.

Try calling this function with i.e.

String test = Testing.encrypt(text,"mySalt");