Update chiphers

ciphers/RSA.java

@@ -2,34 +2,82 @@ package ciphers;
 
 import java.math.BigInteger;
 import java.security.SecureRandom;
+import javax.swing.JOptionPane;
 
 /**
- * Created by Nguyen Duy Tiep on 23-Oct-17.
+ * @author Nguyen Duy Tiep on 23-Oct-17.
  */
-public class RSA {
+public final class RSA {
+
+    /**
+     * Trivial test program.
+     *
+     * @param args
+     * @deprecated TODO remove main and make JUnit Testing or any other
+     * methodology
+     */
+    public static void main(String[] args) {
+
+        RSA rsa = new RSA(1024);
+        String text1 = JOptionPane.showInputDialog("Enter a message to encrypt :");
+
+        String ciphertext = rsa.encrypt(text1);
+        JOptionPane.showMessageDialog(null, "Your encrypted message : " + ciphertext);
+
+        JOptionPane.showMessageDialog(null, "Your message after decrypt : " + rsa.decrypt(ciphertext));
+    }
+
     private BigInteger modulus, privateKey, publicKey;
 
+    /**
+     *
+     * @param bits
+     */
     public RSA(int bits) {
         generateKeys(bits);
     }
 
+    /**
+     *
+     * @param message
+     * @return encrypted message
+     */
     public synchronized String encrypt(String message) {
         return (new BigInteger(message.getBytes())).modPow(publicKey, modulus).toString();
     }
 
+    /**
+     *
+     * @param message
+     * @return encrypted message as big integer
+     */
     public synchronized BigInteger encrypt(BigInteger message) {
         return message.modPow(publicKey, modulus);
     }
 
-    public synchronized String decrypt(String message) {
-        return new String((new BigInteger(message)).modPow(privateKey, modulus).toByteArray());
+    /**
+     *
+     * @param encryptedMessage
+     * @return plain message
+     */
+    public synchronized String decrypt(String encryptedMessage) {
+        return new String((new BigInteger(encryptedMessage)).modPow(privateKey, modulus).toByteArray());
     }
 
-    public synchronized BigInteger decrypt(BigInteger message) {
-        return message.modPow(privateKey, modulus);
+    /**
+     *
+     * @param encryptedMessage
+     * @return plain message as big integer
+     */
+    public synchronized BigInteger decrypt(BigInteger encryptedMessage) {
+        return encryptedMessage.modPow(privateKey, modulus);
     }
 
-    /** Generate a new public and private key set. */
+    /**
+     * Generate a new public and private key set.
+     *
+     * @param bits
+     */
     public synchronized void generateKeys(int bits) {
         SecureRandom r = new SecureRandom();
         BigInteger p = new BigInteger(bits / 2, 100, r);
@@ -47,16 +95,4 @@ public class RSA {
         privateKey = publicKey.modInverse(m);
     }
 
-    /** Trivial test program. */
-    public static void main(String[] args) {
-        RSA rsa = new RSA(1024);
-
-        String text1 = "This is a message";
-        System.out.println("Plaintext: " + text1);
-
-        String ciphertext = rsa.encrypt(text1);
-        System.out.println("Ciphertext: " + ciphertext);
-
-        System.out.println("Plaintext: " + rsa.decrypt(ciphertext));
-    }
 }