top.doudou.common.tool.encrypt.AesUtil Maven / Gradle / Ivy
package top.doudou.common.tool.encrypt;
import org.apache.tomcat.util.codec.binary.Base64;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;
import java.security.SecureRandom;
import java.util.Random;
/**
* @Description AES加、解密算法工具类
* @Author 傻男人 <[email protected]>
* @Date 2020-10-21 16:19
* @Version V1.0
*/
public class AesUtil {
/**
* 加密算法AES
*/
private static final String KEY_ALGORITHM = "AES";
/**
* key的长度，Wrong key size: must be equal to 128, 192 or 256
* 传入时需要16、24、36
*/
private static final Integer KEY_LENGTH = 16 * 8;
/**
* 算法名称/加密模式/数据填充方式
* 默认：AES/ECB/PKCS5Padding
*/
private static final String ALGORITHMS = "AES/ECB/PKCS5Padding";
/**
* 后端AES的key，由静态代码块赋值
*/
public static String key;
/**
* 不能在代码中创建
* JceSecurity.getVerificationResult 会将其put进 private static final Map中，导致内存缓便被耗尽
*/
private static final BouncyCastleProvider PROVIDER = new BouncyCastleProvider();
static {
key = getKey();
}
/**
* 获取key
*/
public static String getKey() {
StringBuilder uid = new StringBuilder();
//产生16位的强随机数
Random rd = new SecureRandom();
for (int i = 0; i < KEY_LENGTH / 8; i++) {
//产生0-2的3位随机数
int type = rd.nextInt(3);
switch (type) {
case 0:
//0-9的随机数
uid.append(rd.nextInt(10));
break;
case 1:
//ASCII在65-90之间为大写,获取大写随机
uid.append((char) (rd.nextInt(25) + 65));
break;
case 2:
//ASCII在97-122之间为小写，获取小写随机
uid.append((char) (rd.nextInt(25) + 97));
break;
default:
break;
}
}
return uid.toString();
}
/**
* 加密
*
* @param content 加密的字符串
* @param encryptKey key值
*/
public static String encrypt(String content, String encryptKey) throws Exception {
//设置Cipher对象
Cipher cipher = Cipher.getInstance(ALGORITHMS, PROVIDER);
cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(encryptKey.getBytes(), KEY_ALGORITHM));
//调用doFinal
// 转base64
return Base64.encodeBase64String(cipher.doFinal(content.getBytes(StandardCharsets.UTF_8)));
}
/**
* 解密
*
* @param encryptStr 解密的字符串
* @param decryptKey 解密的key值
*/
public static String decrypt(String encryptStr, String decryptKey) throws Exception {
//base64格式的key字符串转byte
byte[] decodeBase64 = Base64.decodeBase64(encryptStr);
//设置Cipher对象
Cipher cipher = Cipher.getInstance(ALGORITHMS,PROVIDER);
cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(decryptKey.getBytes(), KEY_ALGORITHM));
//调用doFinal解密
return new String(cipher.doFinal(decodeBase64));
}
}