AES加密算法

package org.example.test;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.security.NoSuchAlgorithmException;
import java.util.Base64;

public class AESExample {
    public static void main(String[] args) {
        try {
            // 生成AES密钥
            SecretKey key = generateAESKey(256);
            System.out.println("Generated AES Key: " + key);

            String s = Base64.getEncoder().encodeToString(key.getEncoded());
            System.out.println(s);


            SecretKeySpec aes = new SecretKeySpec(Base64.getDecoder().decode(s), "AES");



            // 加密数据
            String data = "This is a secret message.";
            String encryptedData = encrypt(data, aes);
            System.out.println("Encrypted Data: " + encryptedData);

            // 解密数据
            String decryptedData = decrypt(encryptedData, aes);
            System.out.println("Decrypted Data: " + decryptedData);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static SecretKey generateAESKey(int keySize) throws NoSuchAlgorithmException {
        KeyGenerator keyGen = KeyGenerator.getInstance("AES");
        keyGen.init(keySize); // 128, 192, or 256 bits
        return keyGen.generateKey();
    }

    public static String encrypt(String data, SecretKey key) throws Exception {
        Cipher cipher = Cipher.getInstance("AES");
        cipher.init(Cipher.ENCRYPT_MODE, key);

        byte[] encryptedData = cipher.doFinal(data.getBytes());
        return Base64.getEncoder().encodeToString(encryptedData);
    }

    public static String decrypt(String encryptedData, SecretKey key) throws Exception {
        Cipher cipher = Cipher.getInstance("AES");
        cipher.init(Cipher.DECRYPT_MODE, key);

        byte[] decodedData = Base64.getDecoder().decode(encryptedData);
        byte[] decryptedData = cipher.doFinal(decodedData);
        return new String(decryptedData);
    }
}