Write a JAVA program that reads from the keyboard a small pa

Write a JAVA program that reads from the keyboard a small password and then offers two options: 1. enter your name and a filename to save or 2. enter a file name to load. With the option 1 proceed to save to the file an encrypted version of your name (details below), with the option 2 proceed to load the information from the file and decrypt the name and print it to the screen. The options 1 and 2 are in reverse (1 saves the encrypted information to the file, 2 decrypts the information from the file). Details of the encryption: Say your name is Andrei and you chose the password 1234, then you do XOR between the ASCII code for A (first letter in your name) and the ASCII code for 1(first letter in your password), I will denote this operation (A,1) then you do XOR between n and 2 (n,2) (second letter in your name with second letter in password) and so on, thus we will have the following operations to perform: (A,1) (n,2) (d,3) (r,4) (e,1) (i,2). Obviously, if you would choose the password qwer then the XOR operations will be between the following pairs: (A,q)(n,w)(d,e)(r,r)(e,q)(i,w). The trick is that the encrypted text can be decrypted due to the following property of XOR: A XOR B=C; C XOR B=A, thus if I have the results of the XOR operations in the file (and this is your name encrypted) then it is sufficient to do XOR with the same password (with the same ASCII codes) and I will get back the original string. For example, with the first password, (A XOR 1) XOR 1 =A, (n XOR 2) XOR 2=n and so on: ((A,1),1) ((n,2),2) ((d,3),3) ((r,4),4) ((e,1),1) ((i,2),2)= A n d r e i.

Solution

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

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

public class Assignment8 {
   public static void main(String[] args) throws IOException{
       // read user name and password
       Scanner sc=new Scanner(System.in);
       System.out.println(\"Enter user Name\");
       String name=sc.next();
       System.out.println(\"Enter password\");
       String password=sc.next();
       String encrptedElement = encode(name,password);
       File file = new File(\"EncryptedFile.txt\");
      
       // creates the EncryptedFile
       file.createNewFile();
      
       // creates a FileWriter Object
       FileWriter writer = new FileWriter(file);
      
       // Writes the content to the file
       writer.write(encrptedElement);
       writer.flush();
       writer.close();
       BufferedReader br = null;

               try {

                   String sCurrentLine;

// reading from file

                   br = new BufferedReader(new FileReader(\"EncryptedFile.txt\"));

                   while ((sCurrentLine = br.readLine()) != null) {
                       String[] s=sCurrentLine.split(\" \");
                       String decrytedElement= decode(s[0], s[1]);
                       System.out.println(decrytedElement);
                   }

               } catch (IOException e) {
                   e.printStackTrace();
               } finally {
                   try {
                       if (br != null)br.close();
                   } catch (IOException ex) {
                       ex.printStackTrace();
                   }
               }
   }
// method for encoding

   public static String encode(String name, String key) {
   return base64Encode(xorWithKey(name.getBytes(), key.getBytes()));
   }

   // method for decoding

public static String decode(String name, String key) {
   return new String(xorWithKey(base64Decode(name), key.getBytes()));
   }

   // method for doing XOR operation

private static byte[] xorWithKey(byte[] a, byte[] key) {
   byte[] out = new byte[a.length];
   for (int i = 0; i < a.length; i++) {
   out[i] = (byte) (a[i] ^ key[i%key.length]);
   }
   return out;
   }

   private static byte[] base64Decode(String name) {
   try {
   BASE64Decoder d = new BASE64Decoder();
   return d.decodeBuffer(name);
   } catch (IOException e) {throw new RuntimeException(e);}
   }

   private static String base64Encode(byte[] bytes) {
   BASE64Encoder enc = new BASE64Encoder();
   return enc.encode(bytes).replaceAll(\"\\\\s\", \"\");

   }
   }