这里提供一个RSA加密算法的工具类，其中包含生成密钥、加密、解密、加签、验签等RSA常用的方法，可以直接使用

引入 Maven 依赖，(如果不引入则需要修改 base64加密、解密方法为 java.ultils.base64)

<dependency>
    <groupId>commons-codec</groupId>
    <artifactId>commons-codec</artifactId>
</dependency>
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
</dependency>
<dependency>
    <groupId>com.auth0</groupId>
    <artifactId>java-jwt</artifactId>
    <version>3.19.2</version>
</dependency>
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
</dependency>

RSA工具类

package cn.lzscxb.common.utils;
import org.apache.commons.codec.binary.Base64;
import javax.crypto.Cipher;
import java.io.ByteArrayOutputStream;
import java.nio.charset.StandardCharsets;
import java.security.*;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;
/**
* @Description RSA非对称加密算法工具类
* @Author LzsCxb
* @Date 2022/07/04 20:26
*/
public class RSAUtils {
/**
* RSA最大加密明文大小 2048/8-11
*/
private static final int MAX_ENCRYPT_BLOCK = 245;
/**
* RSA最大解密密文大小 2048/8
*/
private static final int MAX_DECRYPT_BLOCK = 256;
/**
* 定义加密方式
*/
public static final String KEY_RSA = "RSA";
/**
* 定义公钥
*/
public static final String KEY_RSA_PUBLICKEY = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAhbMJG9i6O0T1hQ8oCoThMAg/0mlcerjYn+wMdZudoDCeEbxKYebs+WoNvBmV26A/co9yJ2+aUIf60kkJ6YwDh9pXSk2vgm7x0TAZ9HzRhpk6td4JO4HM9QpPaQG2Z3Tw8DnhNk7yGADp+weLqgULDDlUI7lm1s1G9OSY+ZK2TwjKPSC4j1CnjD6kvSW1qVGB0GhkreX877Rop+KbOmVE+JtQQgc+DcOgyMjGtSvDGrwBsI569wrywlOeFMLqVDlVLi3ugWDSEn3EHz63Nj442VSfR6ukxtifIwmogUI4VplXQoO4Am6kKH50tkggqVBNFGh0s5qavpig0XYkn42+6QIDAQAB";
/**
* 定义私钥
*/
public static final String KEY_RSA_PRIVATEKEY = "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";
/**
* 定义签名算法
*/
private final static String KEY_RSA_SIGNATURE = "sha256withRSA";
/**
* 生成公私密钥对
*/
public static Map<String, Object> init() {
Map<String, Object> map = null;
try {
KeyPairGenerator generator = KeyPairGenerator.getInstance(KEY_RSA);
//设置密钥对的bit数，越大越安全，但速度减慢，一般使用512或1024、2048
generator.initialize(2048);
KeyPair keyPair = generator.generateKeyPair();
// 获取公钥
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
// 获取私钥
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
// 将密钥对封装为Map
map = new HashMap<String, Object>(2);
map.put(KEY_RSA_PUBLICKEY, publicKey);
map.put(KEY_RSA_PRIVATEKEY, privateKey);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
return map;
}
/**
* 获取 RSAPublicKey
*/
public static RSAPublicKey getPublicKey() throws Exception {
byte[] decoded = Base64.decodeBase64(KEY_RSA_PUBLICKEY);
KeyFactory factory = KeyFactory.getInstance(KEY_RSA);
PublicKey publicKey = factory.generatePublic(new X509EncodedKeySpec(decoded));
return (RSAPublicKey) publicKey;
}
/**
* 获取 RSAPrivateKey
*/
public static RSAPrivateKey getPrivateKey() throws Exception {
byte[] decoded = Base64.decodeBase64(KEY_RSA_PRIVATEKEY);
KeyFactory factory = KeyFactory.getInstance(KEY_RSA);
PrivateKey privateKey = factory.generatePrivate(new PKCS8EncodedKeySpec(decoded));
return (RSAPrivateKey) privateKey;
}
/**
* 公钥加密  如果大于245则分段加密
*/
public static String encryptByPublic(String encryptingStr, String publicKeyStr) {
try {
// 将公钥由字符串转为UTF-8格式的字节数组
byte[] publicKeyBytes = Base64.decodeBase64(publicKeyStr);
// 获得公钥
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(publicKeyBytes);
// 取得待加密数据
byte[] data = encryptingStr.getBytes(StandardCharsets.UTF_8);
KeyFactory factory;
factory = KeyFactory.getInstance(KEY_RSA);
PublicKey publicKey = factory.generatePublic(keySpec);
// 对数据加密
Cipher cipher = Cipher.getInstance(factory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段加密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
} else {
cache = cipher.doFinal(data, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_ENCRYPT_BLOCK;
}
byte[] encryptedData = out.toByteArray();
out.close();
// 返回加密后由Base64编码的加密信息
return new String(Base64.encodeBase64(encryptedData));
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 私钥解密 如果大于256则分段解密
*/
public static String decryptByPrivate(String encryptedStr, String privateKeyStr) {
try {
// 对私钥解密
byte[] privateKeyBytes = Base64.decodeBase64(privateKeyStr);
// 获得私钥
PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(privateKeyBytes);
// 获得待解密数据
byte[] data = Base64.decodeBase64(encryptedStr);
KeyFactory factory = KeyFactory.getInstance(KEY_RSA);
PrivateKey privateKey = factory.generatePrivate(keySpec);
// 对数据解密
Cipher cipher = Cipher.getInstance(factory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, privateKey);
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段解密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
cache = cipher.doFinal(data, offSet, MAX_DECRYPT_BLOCK);
} else {
cache = cipher.doFinal(data, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_DECRYPT_BLOCK;
}
byte[] decryptedData = out.toByteArray();
out.close();
// 返回UTF-8编码的解密信息
return new String(decryptedData, StandardCharsets.UTF_8);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 私钥加密  如果大于245则分段加密
*/
public static String encryptByPrivate(String encryptingStr, String privateKeyStr) {
try {
byte[] privateKeyBytes = Base64.decodeBase64(privateKeyStr);
// 获得私钥
PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(privateKeyBytes);
// 取得待加密数据
byte[] data = encryptingStr.getBytes(StandardCharsets.UTF_8);
KeyFactory factory = KeyFactory.getInstance(KEY_RSA);
PrivateKey privateKey = factory.generatePrivate(keySpec);
// 对数据加密
Cipher cipher = Cipher.getInstance(factory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, privateKey);
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段加密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
} else {
cache = cipher.doFinal(data, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_ENCRYPT_BLOCK;
}
byte[] encryptedData = out.toByteArray();
out.close();
// 返回加密后由Base64编码的加密信息
return new String(Base64.encodeBase64(encryptedData));
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 公钥解密 如果大于256则分段解密
*/
public static String decryptByPublic(String encryptedStr, String publicKeyStr) {
try {
// 对公钥解密
byte[] publicKeyBytes = Base64.decodeBase64(publicKeyStr);
// 取得公钥
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(publicKeyBytes);
// 取得待加密数据
byte[] data = Base64.decodeBase64(encryptedStr);
KeyFactory factory = KeyFactory.getInstance(KEY_RSA);
PublicKey publicKey = factory.generatePublic(keySpec);
// 对数据解密
Cipher cipher = Cipher.getInstance(factory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, publicKey);
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段解密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
cache = cipher.doFinal(data, offSet, MAX_DECRYPT_BLOCK);
} else {
cache = cipher.doFinal(data, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_DECRYPT_BLOCK;
}
byte[] decryptedData = out.toByteArray();
out.close();
// 返回UTF-8编码的解密信息
return new String(decryptedData, StandardCharsets.UTF_8);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 用私钥对加密数据进行签名
*/
public static String sign(String encryptedStr, String privateKey) {
String str = "";
try {
//将私钥加密数据字符串转换为字节数组
byte[] data = encryptedStr.getBytes();
// 解密由base64编码的私钥
byte[] bytes = Base64.decodeBase64(privateKey);
// 构造PKCS8EncodedKeySpec对象
PKCS8EncodedKeySpec pkcs = new PKCS8EncodedKeySpec(bytes);
// 指定的加密算法
KeyFactory factory = KeyFactory.getInstance(KEY_RSA);
// 取私钥对象
PrivateKey key = factory.generatePrivate(pkcs);
// 用私钥对信息生成数字签名
Signature signature = Signature.getInstance(KEY_RSA_SIGNATURE);
signature.initSign(key);
signature.update(data);
str = new String(Base64.encodeBase64(signature.sign()));
} catch (Exception e) {
e.printStackTrace();
}
return str;
}
/**
* 校验数字签名
*
* @return 校验成功返回true，失败返回false
*/
public static boolean verify(String encryptedStr, String publicKey, String sign) {
boolean flag = false;
try {
//将私钥加密数据字符串转换为字节数组
byte[] data = encryptedStr.getBytes();
// 解密由base64编码的公钥
byte[] bytes = Base64.decodeBase64(publicKey);
// 构造X509EncodedKeySpec对象
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(bytes);
// 指定的加密算法
KeyFactory factory = KeyFactory.getInstance(KEY_RSA);
// 取公钥对象
PublicKey key = factory.generatePublic(keySpec);
// 用公钥验证数字签名
Signature signature = Signature.getInstance(KEY_RSA_SIGNATURE);
signature.initVerify(key);
signature.update(data);
flag = signature.verify(Base64.decodeBase64(sign));
} catch (Exception e) {
e.printStackTrace();
}
return flag;
}
/**
* 功能描述:格式化公私钥 C++格式
* 公钥字符串开头要加上“-----BEGIN PUBLIC KEY-----/n”，结尾加上“/n-----END PUBLIC KEY-----/n”
* 私钥字符串开头要加上“-----BEGIN RSA PRIVATE KEY-----/n”，结尾加上“/n-----END RSA PRIVATE KEY-----/n”
*
* @param str  要格式的字符串, flag
* @param flag true为公 false为私
* @return java.lang.String
* @author xiaobu
* @date 2020/3/18 16:40
* @version 1.0
*/
public static String formatStr(String str, boolean flag) {
StringBuilder sb = new StringBuilder(str);
for (int i = 0, len = sb.length(); i < len; i++) {
if (i % 64 == 0) {
sb.insert(i, "/n");
}
}
if (flag) {
sb = new StringBuilder("-----BEGIN PUBLIC KEY-----").append(sb).append("/n-----END PUBLIC KEY-----/n");
} else {
sb = new StringBuilder("-----BEGIN RSA PRIVATE KEY-----").append(sb).append("/n-----END RSA PRIVATE KEY-----/n");
}
return sb.toString();
}
/**
* 测试方法
*/
public static void main(String[] args) {
// 生成 RSA 密钥
Map<String, Object> map = new HashMap<String, Object>(2);
map = RSAUtils.init();
System.out.println(map);
// 使用密钥进行认证
String publicKey = RSAUtils.KEY_RSA_PUBLICKEY;
String privateKey = RSAUtils.KEY_RSA_PRIVATEKEY;
System.out.println("publicKey = " + publicKey);
System.out.println("privateKey = " + privateKey);
System.out.println("formatStr(publicKey,false) = " + formatStr(publicKey, true));
System.out.println("formatStr(privateKey,false) = " + formatStr(privateKey, false));
//由前四行代码获得公、私密钥
//        publicKey = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAjVgHojy7oZ1Gl/iT9CXgvzlqPyV5wxvSRW7f6qDQh1FreYVTIbyVOees9LDbyFyocLCx6Cz3E4csHJvjwIem6SuZpIpmeJGS5bo04JVK2JwdqbFoIXd1Q5bGsA17nUNlnSR4h3ODM8OCKsC0Qpt1KSvN0WB2JUGBbUFwiPxrwEMLeYntz4cABBA/KYt5Ac9HBk5TDRDpFVlOM43t0B2219GxQOxm1x8fFjwzKV06nwYbmIuqoKqQVlym3FYrYiOdd0/iXXxp4Whi0Hdo7XyfaQhoCCd3FNnFP8Ng0HDAW99HxEaP9eIuC4wCV16o8jsUzm7V/yhTF1NlIPlTQW35hQIDAQAB";
String str = "1 InnoDB 支持表锁和行锁，使用索引作为检索条件修改数据时采用行锁，否则采用表锁。/n" + "2 InnoDB 自动给修改操作加锁，给查询操作不自动加锁" + "3 行锁可能因为未使用索引而升级为表锁，所以除了检查索引是否创建的同时，也需要通过explain执行计划查询索引是否被实际使用。, RSA!";
// 公钥加密，私钥解密
String enStr1 = RSAUtils.encryptByPublic(str, publicKey);
System.out.println("公钥加密后：" + enStr1);
String deStr1 = RSAUtils.decryptByPrivate(enStr1, privateKey);
System.out.println("私钥解密后：" + deStr1);
// 私钥加密，公钥解密
String enStr2 = RSAUtils.encryptByPrivate(str, privateKey);
System.out.println("私钥加密后：" + enStr2);
String deStr2 = RSAUtils.decryptByPublic(enStr2, publicKey);
System.out.println("公钥解密后：" + deStr2);
// 产生签名
String sign = sign(enStr2, privateKey);
System.out.println("签名:" + sign);
// 验证签名
boolean status = verify(enStr2, publicKey, sign);
System.out.println("状态:" + status);
}
}

JWT 工具类

package cn.lzscxb.common.utils;
import cn.lzscxb.entity.exception.ConditionException;
import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.SignatureVerificationException;
import com.auth0.jwt.exceptions.TokenExpiredException;
import com.auth0.jwt.interfaces.Claim;
import com.auth0.jwt.interfaces.DecodedJWT;
import lombok.extern.slf4j.Slf4j;
import java.util.Calendar;
import java.util.Date;
import java.util.Map;
@Slf4j
public class TokenUtils {
private static final String ISSUER = "lzscxb.cn";
private static final Integer EXPIRE =30 ;
/**
* 生成token
*
* @param userId
* @return
* @throws Exception
*/
public static String generateToken(Long userId, String phone, String avatar, String nickname) {
Algorithm algorithm = null;
try {
algorithm = Algorithm.RSA256(RSAUtils.getPublicKey(), RSAUtils.getPrivateKey());
} catch (Exception e) {
throw new RuntimeException(e);
}
Calendar calendar = Calendar.getInstance(); // 日历类用于生成过期时间
calendar.setTime(new Date());
calendar.add(Calendar.SECOND, EXPIRE);
return JWT.create().withKeyId(String.valueOf(userId)).withIssuer(ISSUER).withExpiresAt(calendar.getTime()).withClaim("user_id", userId).withClaim("phone", phone).withClaim("avatar", avatar).withClaim("nickname", nickname).sign(algorithm);
}
public static Map<String, Claim> VerifyToken(String token) {
try {
Algorithm algorithm = Algorithm.RSA256(RSAUtils.getPublicKey(), RSAUtils.getPrivateKey());
JWTVerifier verifier = JWT.require(algorithm).build();
DecodedJWT jwt = verifier.verify(token);
Map<String, Claim> claims = jwt.getClaims();
return claims;
} catch (TokenExpiredException e) {
throw new ConditionException(401, "token 令牌已过期");
} catch (SignatureVerificationException e) {
e.printStackTrace();
log.info(token);
throw new ConditionException(401, "token 令牌无效");
} catch (Exception e) {
throw new RuntimeException(e);
}
}
}