using the KeyGenerator class and showing how to create a SecretKeySpec from an encoded key. : Advanced Encryption Standard « Security « Java Tutorial


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

public class MainClass {
  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");
    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));

36.2.Advanced Encryption Standard
36.2.1.using the KeyGenerator class and showing how to create a SecretKeySpec from an encoded key.
36.2.2.AES Key generator
36.2.3.Tampered message, plain encryption, AES in CTR mode
36.2.4.Tampered message, encryption with digest, AES in CTR mode
36.2.5.Tampered message with HMac, encryption with AES in CTR mode
36.2.6.AES wraps RSA