我们在日常工作中，经常会碰到需要加密的地方，如用户的密码等隐私信息。或者我们在处理一些业务时，需要用到摘要/签名等。我们可能就需要一个工具类啦

在使用该工具类时，需要引入commons-lang3和ommons-codec的jar包，使用其他相关方法替换掉该工具类使用到该jar中的相关方法也可

<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-lang3 -->
<dependency><groupId>org.apache.commons</groupId><artifactId>commons-lang3</artifactId><version>3.12.0</version>
</dependency><!-- https://mvnrepository.com/artifact/commons-codec/commons-codec -->
<dependency><groupId>commons-codec</groupId><artifactId>commons-codec</artifactId><version>1.15</version>
</dependency>

import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.binary.Hex;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.Mac;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.Objects;
import java.util.Random;public class EncryptUtil {private static final Logger logger = LoggerFactory.getLogger(EncryptUtil.class);/*** AES加密** @param data  明文* @param key   密钥* @return      密文*/public static String encryptByAES(String data, String key) {if (StringUtils.isBlank(data) || StringUtils.isBlank(key)) {return null;}// 构建AES密钥SecretKeySpec secretKeySpec = generatorAESKey(key, "AES");Objects.requireNonNull(secretKeySpec, "secretKeySpec can not be null");// 定义填充向量IvParameterSpec ivParameterSpec = new IvParameterSpec("0000000000000000".getBytes());try {// 创建密码器，并设置加密算法/加密模式/填充算法Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");// 以加密的方式用密钥和填充向量初始化密码器cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, ivParameterSpec);// 执行加密，并获得byte[]格式的加密结果。String转byte[]的编码格式为UTF-8byte[] encrypt = cipher.doFinal(data.getBytes(StandardCharsets.UTF_8));// 对byte[]格式结果做Base64转码得到密文结果。return Base64.encodeBase64URLSafeString(encrypt);// return new String(new BASE64Encoder().encode(encrypt));} catch (Exception e) {logger.error("加密失败, data={}, key={} ", data, key, e);return null;}}/*** AES解密** @param encryptData   密文* @param key           密钥* @return              明文*/public static String decryptByAES(String encryptData, String key) {if (StringUtils.isBlank(encryptData) || StringUtils.isBlank(key)) {return null;}// 对（URL安全的）密文做Base64转码（decode解码）得到byte[]格式加密结果byte[] encryptDataBytes = Base64.decodeBase64(encryptData);// 构建AES密钥SecretKeySpec secretKeySpec = generatorAESKey(key, "AES");Objects.requireNonNull(secretKeySpec, "secretKeySpec can not be null");// 定义填充向量IvParameterSpec ivParameterSpec = new IvParameterSpec("0000000000000000".getBytes());try {// 创建密码器，并设置解密算法/解密模式/填充算法Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");// 以解密的方式用密钥和填充向量初始化密码器cipher.init(Cipher.DECRYPT_MODE, secretKeySpec, ivParameterSpec);// 执行解密，并获得byte[]格式的解密结果。byte[] decrypt = cipher.doFinal(encryptDataBytes);// byte[]转String。编码格式是UTF-8return new String(decrypt, StandardCharsets.UTF_8);} catch (Exception e) {logger.error("解密失败, encryptData={}, key={}", encryptData, key, e);return null;}}/** SecureRandom实例化的方式默认为：* SecretKeySpec secretKeySpec = new SecretKeySpec(key.getBytes(), "AES");* 即：keyGenerator.init(new SecureRandom(key.getBytes()));* 会导致在windows上测试正常，但在部分linux操作系统下却出现加密解密异常，如会发现加密的结果值一直会变** 所以需要改成：* SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");* secureRandom.setSeed(key.getBytes());* keyGenerator.init(128, secureRandom);* ...*/private static SecretKeySpec generatorAESKey(String key, String algorithm) {try {// 随机数生成器，指定SHA1PRNG算法SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");// 给定随机种子secureRandom.setSeed(key.getBytes());// 构造密钥生成器，指定为AES算法，不区分大小KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");// 指定密钥长度为128位keyGenerator.init(128, secureRandom);// 生成密钥SecretKey secretKey = keyGenerator.generateKey();// 构建AES密钥return new SecretKeySpec(secretKey.getEncoded(), algorithm);} catch (NoSuchAlgorithmException e) {logger.error("生成秘钥失败, key={}, algorithm={}", key, algorithm);return null;}}/*** 签名** @param data  数据* @param key   密钥* @return      签名*/public static String sign(String data, String key) {// 构建AES密钥SecretKeySpec secretKeySpec = generatorAESKey(key, "HmacSHA1");Objects.requireNonNull(secretKeySpec, "secretKeySpec can not be null");try {// 指定签名算法Mac mac = Mac.getInstance("HmacSHA1");// 设置签名密钥mac.init(secretKeySpec);// 执行签名，并获得byte[]格式签名结果。byte[] rawHmac = mac.doFinal(data.getBytes(StandardCharsets.UTF_8));// 对byte[]格式签名结果做（URL安全的）Base64转码（encode编码）得到最终签名return Base64.encodeBase64URLSafeString(rawHmac);} catch (Exception e) {logger.error("签名失败, data={}, key={}", data, key, e);return null;}}/*** 签名校验** @param data      数据* @param key       密钥* @param signature     需校验的签名* @return              校验结果*/public static boolean verifySign(String data, String key, String signature) {if (StringUtils.isBlank(data) || StringUtils.isBlank(key) || StringUtils.isBlank(signature)) {return false;}return signature.equals(sign(data, key));}/*** MD5加密** @param data  明文* @return      密文*/public static String encryptByMD5(String data) {if (StringUtils.isBlank(data)) {return null;}// 获取随机盐Random random = new Random();StringBuilder salt = new StringBuilder(16);salt.append(random.nextInt(99999999)).append(random.nextInt(99999999));int len = salt.length();if (len < 16) {for (int i = 0; i < 16 - len; i++) {salt.append("0");}}// 加密String encryptData = md5(data + salt);if (StringUtils.isBlank(encryptData)) {return null;}char[] chars = new char[48];for (int i = 0; i < 48; i += 3) {chars[i] = encryptData.charAt(i / 3 * 2);char c = salt.charAt(i / 3);chars[i + 1] = c;chars[i + 2] = encryptData.charAt(i / 3 * 2 + 1);}return new String(chars);}/*** MD5加密校验** @param data      明文* @param encryptData    密文* @return          校验结果*/public static boolean verifyMD5(String data, String encryptData) {if (StringUtils.isBlank(data) || StringUtils.isBlank(encryptData)) {return false;}char[] ch1 = new char[32];char[] ch2 = new char[16];try {for (int i = 0; i < 48; i += 3) {ch1[i / 3 * 2] = encryptData.charAt(i);ch1[i / 3 * 2 + 1] = encryptData.charAt(i + 2);ch2[i / 3] = encryptData.charAt(i + 1);}String salt = new String(ch2);return md5(data + salt).equals(new String(ch1));} catch (Exception e) {logger.warn("校验失败, data={}, encryptData={}", data, encryptData, e);return false;}}private static String md5(String data) {String encStr = null;try {MessageDigest md5 = MessageDigest.getInstance("MD5");md5.update(data.getBytes());encStr = bytesToHex(md5.digest());// encStr = bytesToHex2(md5.digest());// encStr = bytesToHex3(md5.digest());} catch (Exception e) {logger.error("MD5加密失败, data={}", data, e);}return encStr;}/** 把密文转换成十六进制的字符串形式*/private static String bytesToHex(byte[] bytes) {// return new String(new Hex().encode(bytes));return Hex.encodeHexString(bytes);}private static String bytesToHex2(byte[] bytes) {char[] HEX_CHARS = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9','A', 'B', 'C', 'D', 'E', 'F'};char[] chars = new char[32];for (int i = 0; i < chars.length; i = i + 2) {byte b = bytes[i / 2];chars[i] = HEX_CHARS[(b >>> 0x4) & 0xf];chars[i + 1] = HEX_CHARS[b & 0xf];}return new String(chars);}private static String bytesToHex3(byte[] bytes) {StringBuilder hexValue = new StringBuilder();String tmp = null;for (byte b : bytes) {tmp = (Integer.toHexString(b & 0xFF));if (tmp.length() == 1) {hexValue.append("0");}hexValue.append(tmp);}return hexValue.toString();}/*** 自定义加密** @param data  明文* @param key   密钥* @return      密文*/public static String encrypt(String data, String key) {if (StringUtils.isBlank(data)) {return null;}return StringUtils.isNotBlank(key) ? encrypt(union(data, key)) : encrypt(data);}/*** 自定义加密* 先将data进行一次MD5加密，加密后再取加密后的字符串的第1、3、5个字符追加到加密串，再拿这个加密串进行加密** @param data  明文* @return      密文*/public static String encrypt(String data) {if (StringUtils.isBlank(data)) {return null;}String encryptData = md5(data);if (StringUtils.isNotBlank(encryptData)) {encryptData = encryptData + encryptData.charAt(0) + encryptData.charAt(2) + encryptData.charAt(4);encryptData = md5(encryptData);}return encryptData;}/** 将要加密的字符串与key联合为一个字符串*/private static String union(String str, String key) {int strLen = str.length();int keyLen = key.length();Character[] s = new Character[strLen + keyLen];boolean flag = true;int strIdx = 0;int keyIdx = 0;for (int i = 0; i < s.length; i++) {if (flag) {if (strIdx < strLen) {s[i] = str.charAt(strIdx);strIdx++;}if (keyIdx < keyLen) {flag = false;}} else {if (keyIdx < keyLen) {s[i] = key.charAt(keyIdx);keyIdx++;}if (strIdx < strLen) {flag = true;}}}return StringUtils.join(s);}
}