Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.security.Key;
import java.security.Security;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class Main {
    public static void main(String[] args) throws Exception {
        // Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

        byte[] input = "input".getBytes();
        byte[] ivBytes = "1234567812345678".getBytes();

        Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding", "BC");
        KeyGenerator generator = KeyGenerator.getInstance("AES", "BC");
        generator.init(128);
        Key encryptionKey = generator.generateKey();
        System.out.println("key : " + new String(encryptionKey.getEncoded()));

        cipher.init(Cipher.ENCRYPT_MODE, encryptionKey, new IvParameterSpec(ivBytes));
        byte[] cipherText = new byte[cipher.getOutputSize(input.length)];
        int ctLength = cipher.update(input, 0, input.length, cipherText, 0);
        ctLength += cipher.doFinal(cipherText, ctLength);
        Key decryptionKey = new SecretKeySpec(encryptionKey.getEncoded(), encryptionKey.getAlgorithm());

        cipher.init(Cipher.DECRYPT_MODE, decryptionKey, new IvParameterSpec(ivBytes));
        byte[] plainText = new byte[cipher.getOutputSize(ctLength)];
        int ptLength = cipher.update(cipherText, 0, ctLength, plainText, 0);
        ptLength += cipher.doFinal(plainText, ptLength);
        System.out.println("plain : " + new String(plainText));
    }
}