生成祕鑰簡單粗暴

這邊AES祕鑰預設為128位，獲得無政策許可權後可為192或256，因此對應字元為16位，直接生成16位的祕鑰

import java.io.UnsupportedEncodingException;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.interfaces.RSAPrivateKey;
 
import java.security.interfaces.RSAPublicKey;
import java.util.Base64;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;

/**  

* @ClassName: SecretKeyUtils  

* 各祕鑰生成

* @author zhupig3028

* @date 2022年5月10日  
  

*/
public class SecretKeyUtils {
    
    /** AES祕鑰 */
    private static
 
 final String AES_ALGORITHM = "AES";
    
    /** 3DES祕鑰 */
    private static final String DES_ALGORITHM = "DESede";

    /** 祕鑰生成來源 */
    public static final String ALLCHAR = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    
    /**
     * 生成AES金鑰物件
     * @throws NoSuchAlgorithmException 
     
 
*/
    public static String generateAESKey() throws NoSuchAlgorithmException, UnsupportedEncodingException {
        StringBuffer sb = new StringBuffer();
        Random random = new Random();
        for (int i = 0; i < 16; i++) {
            sb.append(ALLCHAR.charAt(random.nextInt(ALLCHAR.length())));
        }
        return sb.toString();
    }

    /**
     * 生成3DES金鑰物件
     */
    public static String generate3DESKey() {
        StringBuffer sb = new StringBuffer();
        Random random = new Random();
        for (int i = 0; i < 24; i++) {
            sb.append(ALLCHAR.charAt(random.nextInt(ALLCHAR.length())));
        }
        return sb.toString();
    }

    /**
     * 隨機生成RSA祕鑰
     * @throws NoSuchAlgorithmException
     */
    public static Map<String,String > genKeyPair() throws NoSuchAlgorithmException {
        HashMap<String, String> stringStringHashMap = new HashMap<>();
        // KeyPairGenerator類用於生成公鑰和私鑰對，基於RSA演算法生成物件
        KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
        // 初始化金鑰對生成器，金鑰大小為96-1024位
        keyPairGen.initialize(1024,new SecureRandom());
        // 生成一個金鑰對，儲存在keyPair中
        KeyPair keyPair = keyPairGen.generateKeyPair();
        // 得到私鑰
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
        // 得到公鑰
        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
        String publicKeyString = new String(Base64.getEncoder().encodeToString(publicKey.getEncoded()));
        // 得到私鑰字串
        String privateKeyString = new String(Base64.getEncoder().encodeToString((privateKey.getEncoded())));
        // 將公鑰和私鑰儲存到Map
        //0表示公鑰
        stringStringHashMap.put("0",publicKeyString);
        //1表示私鑰
        stringStringHashMap.put("1",privateKeyString);
        return stringStringHashMap;
    }

}

Java實現AES加解密

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

import java.util.Base64;
/**

* @ClassName: AESUtils  

* @Description: AES 對稱演算法加密/解密工具類

* @author zhupig3028

* @date 2022年5月10日  
  

*/
public class AESUtils {


    /**
     * 加解密統一編碼方式
     */
    private final static String ENCODING = "utf-8";

    /**
     * 加解密方式
     */
    private final static String ALGORITHM  = "AES";

    /**
     *加密模式及填充方式
     */
    private final static String PATTERN = "AES/ECB/pkcs5padding";

    /**
     * AES加密
     * @param plainText
     * @param key
     * @return
     * @throws Exception
     */
    public static String encrypt(String plainText, String key) throws Exception {
        if (key == null) {
            System.out.print("Key為空null");
            return null;
        }
        // 判斷Key是否為16位
        if (key.length() != 16) {
            System.out.print("Key長度不是16位");
            return null;
        }
        SecretKey secretKey = new SecretKeySpec(key.getBytes(ENCODING), ALGORITHM);
        // AES加密採用pkcs5padding填充
        Cipher cipher = Cipher.getInstance(PATTERN);
        //用密匙初始化Cipher物件
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        //執行加密操作
        byte[] encryptData = cipher.doFinal(plainText.getBytes(ENCODING));
        return Base64.getEncoder().encodeToString(encryptData);
    }


    /**
     * AES解密
     * @param plainText
     * @param key
     * @return
     * @throws Exception
     */
    public static String decrypt(String plainText, String key) throws Exception {
        SecretKey secretKey = new SecretKeySpec(key.getBytes(ENCODING), ALGORITHM);
        // 獲取 AES 密碼器
        Cipher cipher = Cipher.getInstance(PATTERN);
        // 初始化密碼器（解密模型）
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        // 解密資料, 返回明文
        byte[] encryptData = cipher.doFinal(Base64.getDecoder().decode(plainText));
        return new String(encryptData,ENCODING);
    }


}