// call the 'decryptMessage' method in RSA class and decrypt cipher text message
@FXML
private void decryptCipher() {
String cipherTextMessage = cipherText.getText();
String encryptedMessage = rsa.decryptMessage(cipherTextMessage, publicKeyN, privateD);
decryptedCipherText.setText(encryptedMessage);
}
public static void main(String[] args) throws IOException {
/*
Requirements:
- BigInteger and SecureRandom should be used
- p and q should be at least 512-bit
- difference between p and q should be bigger than 2^256
- demonstration of encryption and decryption should be given
- should include encryption and decryption timing
- public key e is 65537
*/
RSA rsa = new RSA();
int plainText;
BigInteger b_plainText, b_cipherText;
int e_start, e_end, encryptTime, d_start, d_end, decryptTime;
if (args.length != 0 && args[0].equalsIgnoreCase("n")) {
System.out.println("Plaintext chosen for you");
plainText = 1325975912;
} else {
System.out.println("Enter a number (string characters not allowed): ");
Scanner StdIn = new Scanner(System.in);
plainText = StdIn.nextInt();
}
b_plainText = BigInteger.valueOf(plainText);
e_start = (int) System.nanoTime();
b_cipherText = rsa.encrypt(b_plainText);
e_end = (int) System.nanoTime();
System.out.println("plaintext:\t" + b_plainText.toString());
System.out.println("ciphertext:\t" + b_cipherText.toString());
d_start = (int) System.nanoTime();
b_plainText = rsa.decrypt(b_cipherText);
d_end = (int) System.nanoTime();
System.out.println("plaintext after decryption:\t" + b_plainText.toString());
encryptTime = e_end - e_start;
decryptTime = d_end - d_start;
System.out.println(
"encryption time (ns): "
+ String.valueOf(encryptTime)
+ ", decryption time (ns): "
+ String.valueOf(decryptTime));
}
// generate prime numbers on 'Generate Prime Numbers' Button click
@FXML
private void generatePrimeNumbers() {
bitsValue = valueBitsPrimary.getText(); // get a bits value entered by the user
// firstPrime = firstPrimary.getText();
// secondPrime = secondPrimary.getText();
if (bitsValue.trim().equals("")) {
makeAlert(
"You have not selected a bits value!!",
"Please select a bits value to generate prime number.");
return; // if the bits value are not entered in the field, break the function and do not
// proceed further
}
rsa.generatePrimes(bitsValue);
// get first prime number
firstPrimary.setText(rsa.getFirstPrime());
// get second prime number
secondPrimary.setText(rsa.getSecondPrime());
}
public static void main(String[] args) {
RSA myRSA = new RSA();
String text = "Ὅσον ζῇς φαίνου";
System.out.println(text);
System.out.println(myRSA.decrypt(myRSA.encrypt(text, myRSA.getPublicKey())));
}
// check if a numbers are prime on 'Check Prime Numbers' Button click
@FXML
private void checkPrimeNumbers() {
boolean firstPrime =
rsa.isPrime(
firstPrimary.getText()); // check if the number is prime and assign a boolean value
boolean secondPrime =
rsa.isPrime(
secondPrimary.getText()); // check if the number is prime and assign a boolean value
if (firstPrime && secondPrime) { // boolean for both numbers is true
rsa.setFirstPrime(firstPrimary.getText());
rsa.setSecondPrime(secondPrimary.getText());
publicKeyN = rsa.getModulus(); // get modulus (public key n)
constantPHI = rsa.getPHI(); // get phi
publicKeyE = rsa.getSecondPublicKey(); // get second public key e
privateD = rsa.getPrivateKey(); // get private key
modulusN.setText(publicKeyN);
phi.setText(constantPHI);
publicE.setText(publicKeyE);
privateKeyD.setText(privateD);
firstPrimary.setStyle(
"-fx-border-color: green;"); // set border color to green if the number is a prime number
secondPrimary.setStyle(
"-fx-border-color: green;"); // set border color to green if the number is a prime number
primeOrNotPrime1.setStyle("-fx-opacity: 1;");
primeOrNotPrime2.setStyle("-fx-opacity: 1;");
primeOrNotPrime1.setImage(
new Image("images/green_accept.jpg")); // display green tick if the number is prime
primeOrNotPrime2.setImage(new Image("images/green_accept.jpg"));
} else if (!firstPrime && secondPrime) { // first number is not a prime number
firstPrimary.setStyle(
"-fx-border-color: red;"); // set border color to red if the number is not a prime number
secondPrimary.setStyle(
"-fx-border-color: green;"); // set border color to green if the number is a prime number
primeOrNotPrime1.setStyle("-fx-opacity: 1;");
primeOrNotPrime2.setStyle("-fx-opacity: 1;");
primeOrNotPrime1.setImage(
new Image("images/error.jpg")); // display red sign if the number is not a prime
primeOrNotPrime2.setImage(new Image("images/green_accept.jpg"));
// call 'makeAlert' function with appropriate message
makeAlert(
"Error!!",
"The first number is not a prime number, please generate or select prime number!");
} else if (firstPrime && !secondPrime) { // second number is not a prime number
firstPrimary.setStyle(
"-fx-border-color: green;"); // set border color to green if the number is a prime number
secondPrimary.setStyle(
"-fx-border-color: red;"); // set border color to red if the number is not a prime number
primeOrNotPrime1.setStyle("-fx-opacity: 1;");
primeOrNotPrime2.setStyle("-fx-opacity: 1;");
primeOrNotPrime1.setImage(new Image("images/green_accept.jpg"));
primeOrNotPrime2.setImage(new Image("images/error.jpg"));
// call 'makeAlert' function with appropriate message
makeAlert(
"Error!!",
"The second number is not a prime number, please generate or select prime number!");
} else { // both numbers are not a prime numbers
firstPrimary.setStyle(
"-fx-border-color: red;"); // set border color to red if the number is not a prime number
secondPrimary.setStyle(
"-fx-border-color: red;"); // set border color to red if the number is not a prime number
primeOrNotPrime1.setStyle("-fx-opacity: 1;");
primeOrNotPrime2.setStyle("-fx-opacity: 1;");
primeOrNotPrime1.setImage(new Image("images/error.jpg"));
primeOrNotPrime2.setImage(new Image("images/error.jpg"));
// call 'makeAlert' function with appropriate message
makeAlert(
"Error!!",
"The both numbers are not a prime numbers, please generate or select prime numbers!");
}
}