前后端RSA互相加解密、加签验签、密钥对生成(Java)_前后端rsa加解密

一、序言

最近有一些安全性要求比较高的场景，我们提供API给第三方商户用于收单，其中有几个功能是绑卡、ATM/POS密码变更。

出于合规和监管要求，第三方商户不能保存卡号、CVV、密码等敏感信息，所以相关的敏感操作必须在接口提供方H5页面中完成。为了最大程度保证安全性，我们决定对敏感信息进行加密传输，同时对请求参数进行加签处理。

由于前端并不需要解密操作，最终我们选择RSA非对称加密，前端这块主要采用jsencrypt进行加解密，jsrsasign用来生成密钥对、加签验签。

---

二、关于PKCS#1和PKCS#8格式密钥

由于Java非对称加解密、加验签都是采用PKCS#8格式的密钥，PKCS#1格式的密钥跑不通，这里先简单介绍一下两者的区别。

1、简介

PKCS#1和PKCS#8是两个不同的数字证书标准。

• PKCS#1是一个公钥加密标准，它定义了使用RSA算法进行加密和签名的格式。主要用于对数字签名、加密以及数字签名验证等应用。

• PKCS#8则是一个私钥保护标准，它定义了私钥的存储格式。它主要用于在文件中对私钥进行保护，以防止意外泄露或不当使用。

总的来说，PKCS#1是针对公钥的标准，而PKCS#8是针对私钥的标准。

2、区别

两者的密钥格式不一样，下面以标准.pem格式为例，看下PKCS#1格式和PKCS#8格式密钥的区别：

• PKCS#1格式私钥：

-----BEGIN RSA PRIVATE KEY-----
MIICXAIBAAKBgQC5BW6T9GVaaG/epGDjPpY3wN0DrBt+NojvxkEgpUdOAxgAepqe
...
TbzKH/LEqZN8WVau3bf41yAx2YoaOsIJJtOUTYcfh14=
-----END RSA PRIVATE KEY-----
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• PKCS#8格式私钥：

-----BEGIN PRIVATE KEY-----
MIICdgIBADANBgkqhkiG9w0BAQEFAASCAmAwggJcAgEAAoGBALkFbpP0ZVpob96k
...
wgkm05RNhx+HXg==
-----END PRIVATE KEY-----
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• PKCS#1格式公钥：

-----BEGIN RSA PUBLIC KEY-----
MIICXAIBAAKBgQC5BW6T9GVaaG/epGDjPpY3wN0DrBt+NojvxkEgpUdOAxgAepqe
...
TbzKH/LEqZN8WVau3bf41yAx2YoaOsIJJtOUTYcfh14=
-----END RSA PUBLIC KEY-----
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• PKCS#8格式公钥：

-----BEGIN PUBLIC KEY-----
MIICdgIBADANBgkqhkiG9w0BAQEFAASCAmAwggJcAgEAAoGBALkFbpP0ZVpob96k
...
wgkm05RNhx+HXg==
-----END PUBLIC KEY-----
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---

二、关于JSEncrypt

JSEncrypt是前端RSA加解密、密钥生成的一个实现方案，API也比较简单，更多请参考：JSEncrypt官网。

官网有个线上的Demo，可以生成非对称密钥，还有加解密。

Home页有相关的使用示例，还是很简单的。

// Create the encryption object and set the key.
var crypt = new JSEncrypt();
crypt.setKey(__YOUR_OPENSSL_PRIVATE_OR_PUBLIC_KEY__); //You can use also setPrivateKey and setPublicKey, they are both alias to setKey

//Eventhough the methods are called setPublicKey and setPrivateKey, remember
//that they are only alias to setKey, so you can pass them both a private or
//a public openssl key, just remember that setting a public key allows you to only encrypt.

var text = 'test';
// Encrypt the data with the public key.
var enc = crypt.encrypt(text);
// Now decrypt the crypted text with the private key.
var dec = crypt.decrypt(enc);

// Now a simple check to see if the round-trip worked.
if (dec === text){
    alert('It works!!!');
} else {
    alert('Something went wrong....');
}
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备注：Download页有JSEncrypt官网demo的源代码。

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三、关于jsrsasign

jsrsasign是一个开源的纯JavaScript加密库，支持RSA/RSAPSS/ECDSA/DSA签名和验签，PKCS#1/5/8公私钥生成等等。

在Github上有两篇文章，一篇是关于如何使用Signature类进行加签、验签的，一篇是关于jsrsasign和Java互用性的，里面有通过Java加签，通过jsrsasign验签的demo。

更多相关类和方法的使用和描述可以参考，jsrsasign API文档说明。

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四、前端RSA加解密、加验签示例

1、相关依赖

// JSEncrypt
npm i jsencrypt

// jsrsasign
npm i jsrsasign

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2、cryptoUtils工具类封装

import CryptoJS from "crypto-js";
import JSEncrypt from "jsencrypt";
import JsRsaSign from "jsrsasign";

/**
 * RSA加密
 * @param publicKey 公钥
 * @param plainText 明文
 * @returns {*} 密文
 */
export function encryptByRSA(publicKey, plainText) {
  const encryptor = new JSEncrypt();
  encryptor.setPublicKey(publicKey);
  return encryptor.encrypt(plainText);
}

/**
 * RSA解密
 * @param privateKey 私钥
 * @param cipherText 密文
 * @returns {*} 明文
 */
export function decryptByRSA(privateKey, cipherText) {
  const decrypter = new JSEncrypt();
  decrypter.setPrivateKey(privateKey);
  return decrypter.decrypt(cipherText);
}

/**
 * 生成RSA密钥对，填充模式为PKCS8。
 * 更多模式参考：<a href="https://kjur.github.io/jsrsasign/api/symbols/KEYUTIL.html">https://kjur.github.io/jsrsasign/api/symbols/KEYUTIL.html</a>
 * @returns {{privateKey: (string|string|*), publicKey: (string|string|*)}}
 */
export function generateRsaKeyWithPKCS8() {
  const keyPair = JsRsaSign.KEYUTIL.generateKeypair("RSA", 1024);
  const privateKey = JsRsaSign.KEYUTIL.getPEM(keyPair.prvKeyObj, "PKCS8PRV");
  const publicKey = JsRsaSign.KEYUTIL.getPEM(keyPair.pubKeyObj);
  return { privateKey, publicKey };
}

/**
 * SHA256和RSA加签
 * @param privateKey 私钥
 * @param msg 加签内容
 * @returns {string} Base64编码签名内容
 */
export function signBySHA256WithRSA(privateKey, msg) {
  const key = JsRsaSign.KEYUTIL.getKey(privateKey);
  const signature = new JsRsaSign.KJUR.crypto.Signature({
    alg: "SHA256withRSA",
  });
  signature.init(key);
  signature.updateString(msg);
  // 签名后的为16进制字符串，这里转换为16进制字符串
  return JsRsaSign.hextob64(signature.sign());
}

/**
 * SHA256和RSA验签
 * @param publicKey 公钥：必须为标准pem格式。如果是PKCS1格式，必须包含-----BEGIN RSA PRIVATE KEY-----，如果是PKCS8格式，必须包含-----BEGIN PRIVATE KEY-----
 * @param base64SignStr Base64编码签名字符串
 * @param msg 原内容
 * @returns {boolean} 是否验签通过
 */
export function verifyBySHA256WithRSA(publicKey, base64SignStr, msg) {
  const key = JsRsaSign.KEYUTIL.getKey(publicKey);
  const signature = new JsRsaSign.KJUR.crypto.Signature({
    alg: "SHA256withRSA",
  });
  signature.init(key);
  signature.updateString(msg);
  // 需要将Base64进制签名字符串转换成16进制字符串
  return signature.verify(JsRsaSign.b64tohex(base64SignStr));
}
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3、测试用例

先在前端测试下密钥对生成，RSA加解密、加验签，测试代码如下：

import * as CryptoUtils from '@/utils/cryptoUtils.js';

const {privateKey, publicKey} = CryptoUtils.generateRsaKeyWithPKCS8();
console.log(`生成的私钥为：\n${privateKey}`);
console.log(`生成的公钥为：\n${publicKey}`);

const cipherText = CryptoUtils.encryptByRSA(publicKey, "test");
console.log(`test加密后的内容为：\n${cipherText}`);

const plainText = CryptoUtils.decryptByRSA(privateKey, cipherText);
console.log(`解密后的内容为：\n${plainText}`);

const signature = CryptoUtils.signBySHA256WithRSA(privateKey, "test");
console.log(`生成的签名：\n${signature}`);

const isVerified = CryptoUtils.verifyBySHA256WithRSA(publicKey, signature, "test");
console.log(`是否验签通过：${isVerified}`);
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控制台输出结果为：

生成的私钥为：
-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----

生成的公钥为：
-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDL9WnTZijcOK7a9g8vdg2dzZNU
gqxhnrZatLEoC2PGybAcgLz9mTjoolqtsQ1FbvGaUHzPL/PbY3oH67CFHDf2VS3O
vEYnNwSLaPOaEHPYwc/mgpNa13jTHj5ElajWgv5+JCe92ONWYCgHtBr8qjMlDYZP
FWXfkEjQE0r/pRnqdwIDAQAB
-----END PUBLIC KEY-----

test加密后的内容为：
KjcaDKLnBbvxRzuKMysqoz9MHRXCUNIH67+XDiFGTJbM8Rjw4Cei0CzjAPjk2jgAR37Kgh6lX2+Xg8AI9wEmzWr08bt8i2FFxVMrcfOCs5zI1y+2T7G9034f5b0gNx/Pc4dDz+1k453vo0AhCC0vrtb1OfbsRu5oOFns0TqoAMY=

解密后的内容为：test

生成的签名：
t0koTqhiWmq/wEvI/ieJq5kZj7Dc/limF7GNVtHNLReqLVBXZvAZrOIwdqda7LBHBSHcRZBISWtbuyDiOR9KFPObrOgOEUOdfACUMzjWKCtO8ZgcQ+U02FyGeeH2rT9rJEJAXDEM+Kn3+H4ZdbrUFPY3jQRl535wnK9CLpxqAG4=

是否验签通过：true
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备注：为什么在前端生成PKCS#8格式密钥呢？
因为在Java中非对称加解密、加验签都是用的PKCS#8，PKCS#1格式密钥需要转换成PKCS#8。

---

五、Java后端RSA加解密、加验签

1、CryptoUtils工具类封装

import com.universe.crypto.CryptoUtils.Algorithm.Encryption;
import com.universe.crypto.CryptoUtils.Algorithm.Signing;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.Getter;
import lombok.NoArgsConstructor;
import org.apache.commons.lang3.StringUtils;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.KeySpec;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Base64;
import java.util.Base64.Decoder;
import java.util.Base64.Encoder;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * 支持AES、DES、RSA加密、数字签名以及生成对称密钥和非对称密钥对
 */
public class CryptoUtils {

	private static final Charset DEFAULT_CHARSET = StandardCharsets.UTF_8;
	private static final Encoder BASE64_ENCODER = Base64.getEncoder();
	private static final Decoder BASE64_DECODER = Base64.getDecoder();

	private static final Map<Algorithm, KeyFactory> KEY_FACTORY_CACHE = new ConcurrentHashMap<>();
	private static final Map<Algorithm, Cipher> CIPHER_CACHE = new HashMap<>();

	/**
	 * 生成对称密钥，目前支持的算法有AES、DES
	 * @param algorithm
	 * @return
	 * @throws NoSuchAlgorithmException
	 */
	public static String generateSymmetricKey(Algorithm algorithm) throws NoSuchAlgorithmException {
		KeyGenerator generator = KeyGenerator.getInstance(algorithm.getName());
		generator.init(algorithm.getKeySize());
		SecretKey secretKey = generator.generateKey();
		return BASE64_ENCODER.encodeToString(secretKey.getEncoded());
	}

	/**
	 * 生成非对称密钥对，目前支持的算法有RSA、DSA。备注：默认生成的密钥格式为PKCS8
	 * @param algorithm
	 * @return
	 * @throws NoSuchAlgorithmException
	 */
	public static AsymmetricKeyPair generateAsymmetricKeyPair(Algorithm algorithm) throws NoSuchAlgorithmException {
		KeyPairGenerator generator = KeyPairGenerator.getInstance(algorithm.getName());
		generator.initialize(algorithm.getKeySize());
		KeyPair keyPair = generator.generateKeyPair();
		String publicKey = BASE64_ENCODER.encodeToString(keyPair.getPublic().getEncoded());
		String privateKey = BASE64_ENCODER.encodeToString(keyPair.getPrivate().getEncoded());
		return new AsymmetricKeyPair(publicKey, privateKey);
	}

	public static String encryptByRSA(String publicKeyText, String plainText) throws Exception {
		return encryptAsymmetrically(publicKeyText, plainText, Encryption.RSA_ECB_PKCS1);
	}

	public static String decryptByRSA(String privateKeyText, String ciphertext) throws Exception {
		return decryptAsymmetrically(privateKeyText, ciphertext, Encryption.RSA_ECB_PKCS1);
	}

	/**
	 * SHA1签名算法和DSA加密算法结合使用生成数字签名
	 * @param privateKeyText
	 * @param msg
	 * @return 数字签名
	 * @throws Exception
	 */
	public static String signBySHA1WithDSA(String privateKeyText, String msg) throws Exception {
		return doSign(privateKeyText, msg, Encryption.DSA, Signing.SHA1WithDSA);
	}

	/**
	 * SHA1签名算法和RSA加密算法结合使用生成数字签名
	 * @param privateKeyText 私钥
	 * @param msg 待加签内容
	 * @return 数字签名
	 * @throws Exception
	 */
	public static String signBySHA1WithRSA(String privateKeyText, String msg) throws Exception {
		return doSign(privateKeyText, msg, Encryption.RSA_ECB_PKCS1, Signing.SHA1WithRSA);
	}

	/**
	 * SHA256签名算法和RSA加密算法结合使用生成数字签名
	 * @param privateKeyText 私钥
	 * @param msg 待加签内容
	 * @return 数字签名
	 * @throws Exception
	 */
	public static String signBySHA256WithRSA(String privateKeyText, String msg) throws Exception {
		return doSign(privateKeyText, msg, Encryption.RSA_ECB_PKCS1, Signing.SHA256WithRSA);
	}

	/**
	 * SHA1签名算法和DSA加密算法检验数字签名
	 * @param publicKeyText 公钥
	 * @param msg 待验签内容
	 * @param signatureText 数字
	 * @return 检验是否成功
	 * @throws Exception
	 */
	public static boolean verifyBySHA1WithDSA(String publicKeyText, String msg, String signatureText) throws Exception {
		return doVerify(publicKeyText, msg, signatureText, Encryption.DSA, Signing.SHA1WithDSA);
	}

	/**
	 * SHA1签名算法和RSA加密算法检验数字签名
	 * @param publicKeyText 公钥
	 * @param msg 待验签内容
	 * @param signatureText 签名
	 * @return 校验是否成功
	 * @throws Exception
	 */
	public static boolean verifyBySHA1WithRSA(String publicKeyText, String msg, String signatureText) throws Exception {
		return doVerify(publicKeyText, msg, signatureText, Encryption.RSA_ECB_PKCS1, Signing.SHA1WithRSA);
	}

	/**
	 * SHA256签名算法和RSA加密算法检验数字签名
	 * @param publicKeyText 公钥
	 * @param msg 待验签内容
	 * @param signatureText 签名
	 * @return 校验是否成功
	 * @throws Exception
	 */
	public static boolean verifyBySHA256WithRSA(String publicKeyText, String msg, String signatureText) throws Exception {
		return doVerify(publicKeyText, msg, signatureText, Encryption.RSA_ECB_PKCS1, Signing.SHA256WithRSA);
	}

	/**
	 * 对称加密
	 * @param secretKey 密钥
	 * @param iv 加密向量，只有CBC模式才支持，如果是CBC则必传
	 * @param plainText 明文
	 * @param algorithm 对称加密算法，如AES、DES
	 * @return
	 * @throws Exception
	 */
	public static String encryptSymmetrically(String secretKey, String iv, String plainText, Algorithm algorithm) throws Exception {
		SecretKey key = decodeSymmetricKey(secretKey, algorithm);
		IvParameterSpec ivParameterSpec = StringUtils.isBlank(iv) ? null : decodeIv(iv);
		byte[] plainTextInBytes = plainText.getBytes(DEFAULT_CHARSET);
		byte[] ciphertextInBytes = transform(algorithm, Cipher.ENCRYPT_MODE, key, ivParameterSpec, plainTextInBytes);

		return BASE64_ENCODER.encodeToString(ciphertextInBytes);
	}

	/**
	 * 对称解密
	 * @param secretKey 密钥
	 * @param iv 加密向量，只有CBC模式才支持，如果是CBC则必传
	 * @param ciphertext 密文
	 * @param algorithm 对称加密算法，如AES、DES
	 * @return
	 * @throws Exception
	 */
	public static String decryptSymmetrically(String secretKey, String iv, String ciphertext, Algorithm algorithm) throws Exception {
		SecretKey key = decodeSymmetricKey(secretKey, algorithm);
		IvParameterSpec ivParameterSpec = StringUtils.isBlank(iv) ? null : decodeIv(iv);
		byte[] ciphertextInBytes = BASE64_DECODER.decode(ciphertext);
		byte[] plainTextInBytes = transform(algorithm, Cipher.DECRYPT_MODE, key, ivParameterSpec, ciphertextInBytes);
		return new String(plainTextInBytes, DEFAULT_CHARSET);
	}

	/**
	 * 非对称加密
	 * @param publicKeyText 公钥
	 * @param plainText 明文
	 * @param algorithm 非对称加密算法
	 * @return
	 * @throws Exception
	 */
	public static String encryptAsymmetrically(String publicKeyText, String plainText, Algorithm algorithm) throws Exception {
		PublicKey publicKey = regeneratePublicKey(publicKeyText, algorithm);
		byte[] plainTextInBytes = plainText.getBytes(DEFAULT_CHARSET);
		byte[] ciphertextInBytes = transform(algorithm, Cipher.ENCRYPT_MODE, publicKey, plainTextInBytes);
		return BASE64_ENCODER.encodeToString(ciphertextInBytes);
	}

	/**
	 * 非对称解密
	 * @param privateKeyText 私钥
	 * @param ciphertext 密文
	 * @param algorithm 非对称加密算法
	 * @return
	 * @throws Exception
	 */
	public static String decryptAsymmetrically(String privateKeyText, String ciphertext, Algorithm algorithm) throws Exception {
		PrivateKey privateKey = regeneratePrivateKey(privateKeyText, algorithm);
		byte[] ciphertextInBytes = BASE64_DECODER.decode(ciphertext);
		byte[] plainTextInBytes = transform(algorithm, Cipher.DECRYPT_MODE, privateKey, ciphertextInBytes);
		return new String(plainTextInBytes, DEFAULT_CHARSET);
	}

	/**
	 * 生成数字签名
	 * @param privateKeyText 私钥
	 * @param msg 传输的数据
	 * @param encryptionAlgorithm 加密算法，见Algorithm中的加密算法
	 * @param signatureAlgorithm 签名算法，见Algorithm中的签名算法
	 * @return 数字签名
	 * @throws Exception
	 */
	public static String doSign(String privateKeyText, String msg, Algorithm encryptionAlgorithm, Algorithm signatureAlgorithm)
		throws Exception {
		PrivateKey privateKey = regeneratePrivateKey(privateKeyText, encryptionAlgorithm);
		// Signature只支持签名算法
		Signature signature = Signature.getInstance(signatureAlgorithm.getName());
		signature.initSign(privateKey);
		signature.update(msg.getBytes(DEFAULT_CHARSET));
		byte[] signatureInBytes = signature.sign();
		return BASE64_ENCODER.encodeToString(signatureInBytes);
	}

	/**
	 * 数字签名验证
	 * @param publicKeyText 公钥
	 * @param msg 传输的数据
	 * @param signatureText 数字签名
	 * @param encryptionAlgorithm 加密算法，见Algorithm中的加密算法
	 * @param signatureAlgorithm 签名算法，见Algorithm中的签名算法
	 * @return 校验是否成功
	 * @throws Exception
	 */
	public static boolean doVerify(String publicKeyText, String msg, String signatureText, Algorithm encryptionAlgorithm,
		Algorithm signatureAlgorithm) throws Exception {
		PublicKey publicKey = regeneratePublicKey(publicKeyText, encryptionAlgorithm);
		Signature signature = Signature.getInstance(signatureAlgorithm.getName());
		signature.initVerify(publicKey);
		signature.update(msg.getBytes(DEFAULT_CHARSET));
		return signature.verify(BASE64_DECODER.decode(signatureText));
	}

	/**
	 * 将密钥进行Base64位解码，重新生成SecretKey实例
	 * @param secretKey 密钥
	 * @param algorithm 算法
	 * @return
	 */
	private static SecretKey decodeSymmetricKey(String secretKey, Algorithm algorithm) {
		byte[] key = BASE64_DECODER.decode(secretKey);
		return new SecretKeySpec(key, algorithm.getName());
	}

	private static IvParameterSpec decodeIv(String iv) {
		byte[] ivInBytes = BASE64_DECODER.decode(iv);
		return new IvParameterSpec(ivInBytes);
	}

	private static PublicKey regeneratePublicKey(String publicKeyText, Algorithm algorithm)
		throws NoSuchAlgorithmException, InvalidKeySpecException {
		byte[] keyInBytes = BASE64_DECODER.decode(publicKeyText);
		KeyFactory keyFactory = getKeyFactory(algorithm);
		// 公钥必须使用RSAPublicKeySpec或者X509EncodedKeySpec
		KeySpec publicKeySpec = new X509EncodedKeySpec(keyInBytes);
		PublicKey publicKey = keyFactory.generatePublic(publicKeySpec);
		return publicKey;
	}

	private static PrivateKey regeneratePrivateKey(String key, Algorithm algorithm) throws Exception {
		byte[] keyInBytes = BASE64_DECODER.decode(key);
		KeyFactory keyFactory = getKeyFactory(algorithm);
		// 私钥必须使用RSAPrivateCrtKeySpec或者PKCS8EncodedKeySpec
		KeySpec privateKeySpec = new PKCS8EncodedKeySpec(keyInBytes);
		PrivateKey privateKey = keyFactory.generatePrivate(privateKeySpec);
		return privateKey;
	}

	private static KeyFactory getKeyFactory(Algorithm algorithm) throws NoSuchAlgorithmException {
		KeyFactory keyFactory = KEY_FACTORY_CACHE.get(algorithm);
		if (keyFactory == null) {
			keyFactory = KeyFactory.getInstance(algorithm.getName());
			KEY_FACTORY_CACHE.put(algorithm, keyFactory);
		}

		return keyFactory;
	}

	private static byte[] transform(Algorithm algorithm, int mode, Key key, byte[] msg) throws Exception {
		return transform(algorithm, mode, key, null, msg);
	}

	private static byte[] transform(Algorithm algorithm, int mode, Key key, IvParameterSpec iv, byte[] msg) throws Exception {
		Cipher cipher = CIPHER_CACHE.get(algorithm);
		// double check，减少上下文切换
		if (cipher == null) {
			synchronized (CryptoUtils.class) {
				if ((cipher = CIPHER_CACHE.get(algorithm)) == null) {
					cipher = determineWhichCipherToUse(algorithm);
					CIPHER_CACHE.put(algorithm, cipher);
				}
				cipher.init(mode, key, iv);
				return cipher.doFinal(msg);
			}
		}

		synchronized (CryptoUtils.class) {
			cipher.init(mode, key, iv);
			return cipher.doFinal(msg);
		}
	}

	private static Cipher determineWhichCipherToUse(Algorithm algorithm) throws NoSuchAlgorithmException, NoSuchPaddingException {
		Cipher cipher;
		String transformation = algorithm.getTransformation();
		// 官方推荐的transformation使用algorithm/mode/padding组合，SunJCE使用ECB作为默认模式，使用PKCS5Padding作为默认填充
		if (StringUtils.isNotEmpty(transformation)) {
			cipher = Cipher.getInstance(transformation);
		} else {
			cipher = Cipher.getInstance(algorithm.getName());
		}

		return cipher;
	}

	/**
	 * 算法分为加密算法和签名算法，更多算法实现见：<br/>
	 * <a href="https://docs.oracle.com/javase/8/docs/technotes/guides/security/StandardNames.html#impl">jdk8中的标准算法</a>
	 */
	public static class Algorithm {

		public interface Encryption {
			Algorithm AES_ECB_PKCS5 = new Algorithm("AES", "AES/ECB/PKCS5Padding", 128);
			Algorithm AES_CBC_PKCS5 = new Algorithm("AES", "AES/CBC/PKCS5Padding", 128);
			Algorithm DES_ECB_PKCS5 = new Algorithm("DES", "DES/ECB/PKCS5Padding", 56);
			Algorithm DES_CBC_PKCS5 = new Algorithm("DES", "DES/CBC/PKCS5Padding", 56);
			Algorithm RSA_ECB_PKCS1 = new Algorithm("RSA", "RSA/ECB/PKCS1Padding", 1024);
			Algorithm DSA = new Algorithm("DSA", 1024);
		}

		public interface Signing {
			Algorithm SHA1WithDSA = new Algorithm("SHA1withDSA", 1024);
			Algorithm SHA1WithRSA = new Algorithm("SHA1WithRSA", 2048);
			Algorithm SHA256WithRSA = new Algorithm("SHA256WithRSA", 2048);
		}

		@Getter
		private String name;
		@Getter
		private String transformation;
		@Getter
		private int keySize;

		public Algorithm(String name, int keySize) {
			this(name, null, keySize);
		}

		public Algorithm(String name, String transformation, int keySize) {
			this.name = name;
			this.transformation = transformation;
			this.keySize = keySize;
		}

	}

	@Data
	@NoArgsConstructor
	@AllArgsConstructor
	public static class AsymmetricKeyPair {

		private String publicKey;
		private String privateKey;
	}

}
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2、测试用例

AsymmetricKeyPair keyPair = CryptoUtils.generateAsymmetricKeyPair(Encryption.RSA_ECB_PKCS1);
String privateKey = keyPair.getPrivateKey();
String publicKey = keyPair.getPublicKey();
System.out.println("生成的私钥为：\n" + privateKey);
System.out.println("生成的公钥为：\n" + publicKey);

String cipherText = CryptoUtils.encryptByRSA(publicKey, "test");
String plainText = CryptoUtils.decryptByRSA(privateKey, cipherText);
System.out.println("test加密后的密文为：\n" + cipherText);
System.out.println("解密后的明文为：" + plainText);

String signature = CryptoUtils.signBySHA256WithRSA(privateKey, "message");
boolean isVerified = CryptoUtils.verifyBySHA256WithRSA(publicKey, "message", signature);
System.out.println("message加签后的签名为：" + signature);
System.out.println("验签是否通过：" + isVerified);
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控制台输出如下：

生成的私钥为：
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

生成的公钥为：
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC+E3QapcSQciVEUqjc7YT9fLdkOrc5ncH6EyZGtMsvw4xC9f5gT3XMoMFgX1WCwb8LgVDshuKW3/3XtKZoHPW+/ksDaqqR7Zi8WhKlt3m6L5tEdlBaJtDkv+V+aXVjSrig0wqT9sQtSUn0akvu1jYBRIQiu4UVgcyKYn17y82TbQIDAQAB

test加密后的密文为：
EA19/wkHbdXTc8sfLFhmnp/MWW3PLx2LeYFHWFNdhvY38+Zoa4Ci8HJw8okkxzTfsSkgsiybMaz82rwF9lfcuEWzjbuGeVOvdkI0p/Cv+PDfikMYwOsxA7OqBJ/Hktn25l/ryEv7TxYlMFQ48jB0KPw/0Ivec9qfX2pgnyBl7WM=

解密后的明文为：test

message加签后的签名为：
AByFyRoc/321db16voe9NQaicwkscTOGjBZGefWzB7dMadWXBtUPIK3CUXADLiiesehgAAcDbl06qVz++x/6xeWPCK2ucCfn9dFybZfmAIsn+3TATuDQIFvz/m2cHQAuH9fkmiGgMPOVY/VcILwri3RETuQ+wz4YSmP89o1cFqk=

验签是否通过：true
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---

六、前后端加解密、加验签交互测试

1、前端加密，后端解密

这里我们用前端生成的密钥对做测试。

(1) 前端代码

import * as CryptoUtils from '@/utils/cryptoUtils.js';

const {privateKey, publicKey} = CryptoUtils.generateRsaKeyWithPKCS8();
console.log(`生成的私钥为：\n${privateKey}`);
console.log(`生成的公钥为：\n${publicKey}`);

const cipherText = CryptoUtils.encryptByRSA(publicKey, "test");
console.log(`test加密后的内容为：\n${cipherText}`);
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控制台输出：

生成的私钥为：
-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----

生成的公钥为：
-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDL9WnTZijcOK7a9g8vdg2dzZNU
gqxhnrZatLEoC2PGybAcgLz9mTjoolqtsQ1FbvGaUHzPL/PbY3oH67CFHDf2VS3O
vEYnNwSLaPOaEHPYwc/mgpNa13jTHj5ElajWgv5+JCe92ONWYCgHtBr8qjMlDYZP
FWXfkEjQE0r/pRnqdwIDAQAB
-----END PUBLIC KEY-----

test加密后的内容为：
KjcaDKLnBbvxRzuKMysqoz9MHRXCUNIH67+XDiFGTJbM8Rjw4Cei0CzjAPjk2jgAR37Kgh6lX2+Xg8AI9wEmzWr08bt8i2FFxVMrcfOCs5zI1y+2T7G9034f5b0gNx/Pc4dDz+1k453vo0AhCC0vrtb1OfbsRu5oOFns0TqoAMY=

解密后的内容为：test

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(2) 后端代码

String privateKey = "MIICdgIBADANBgkqhkiG9w0BAQEFAASCAmAwggJcAgEAAoGBAMv1adNmKNw4rtr2Dy92DZ3Nk1SCrGGetlq0sSgLY8bJsByAvP2ZOOiiWq2xDUVu8ZpQfM8v89tjegfrsIUcN/ZVLc68Ric3BIto85oQc9jBz+aCk1rXeNMePkSVqNaC/n4kJ73Y41ZgKAe0GvyqMyUNhk8VZd+QSNATSv+lGep3AgMBAAECgYBoKMvDry98z+HUZsb4iQSJK1xrU1SvgftEtXSnq7Fn6sZquABMTry2aXt/qqTJadAu653hvW5/Av1mICKEyBV3aT4OjQRGPMgp6WhXvQepUIuyi9qlfUVsJy/+J0zGKZeKsCFlwZ2e2j4Un7Bb//pgUfjJrbPtwC7U85oHjtJb6QJBAOdcm07ThSXFbicj2MuX9Gh7geMjncf6aqnrOwUFjO0d5OxfYRAxrZD1GghygHyoJ4ZOHgJ0s6HVEYjg/u6DBdsCQQDhrb4IOVdSew2cW15ft/5DAKUXRRQBfz0OxOs0Uv5k7zqI+YmysWVRGaZgj8oMZ7gYxN1eYNOKTwVjiuwbuyaVAkEA0OGSMpPT1WsvbVT26bFyb1Z6yTihvif/XxPKgFknh/kCcsoWFwnS+1nevBusl181+BLVE0CL4aM9pogEghB3GwJAWJTVzmyTdfCO+xxyAqg5yRrrsiKPI7dJxA5PNA6PhBbSpwkrn1Q6LIcg4y4NZKkhfbdoHK9s2REDUHsrCgd/sQJAALEe+PCXhcHWnwbm4kRFyJCO4dWkii7o28ohTRourlNsoEmiu1+7lt7PY1+C3D+6A4FFCY/HpGM0i0lJue8rZA==";
String cipherText = "KjcaDKLnBbvxRzuKMysqoz9MHRXCUNIH67+XDiFGTJbM8Rjw4Cei0CzjAPjk2jgAR37Kgh6lX2+Xg8AI9wEmzWr08bt8i2FFxVMrcfOCs5zI1y+2T7G9034f5b0gNx/Pc4dDz+1k453vo0AhCC0vrtb1OfbsRu5oOFns0TqoAMY=";

// 解密后的明文应该为test
String plainText = CryptoUtils.decryptByRSA(privateKey, cipherText);
System.out.println("解密后的明文为：" + plainText);
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控制台输出如下：

解密后的明文为：test
1

备注：

• 从前端复制过来的密钥需要去掉-----BEGIN PRIVATE KEY-----前缀。
• 从前端复制过来的密钥带有换行，记得去掉中间的换行符。

2、后端加密，前端解密

这里我们用后端生成的密钥对做测试。

(1) 后端代码

AsymmetricKeyPair keyPair = CryptoUtils.generateAsymmetricKeyPair(Encryption.RSA_ECB_PKCS1);
String privateKey = keyPair.getPrivateKey();
String publicKey = keyPair.getPublicKey();
System.out.println("生成的私钥为：\n" + privateKey);
System.out.println("生成的公钥为：\n" + publicKey);

String cipherText = CryptoUtils.encryptByRSA(publicKey, "test");
System.out.println("test加密后的内容为：\n" + cipherText);
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控制台输出为：

生成的私钥为：
MIICdQIBADANBgkqhkiG9w0BAQEFAASCAl8wggJbAgEAAoGBAJPh8WiDo3dhKHW9w86D4DX84pHAG03PIeOHCSezbyKeyKsuHA3qayGJ7JqQgWis557uawz95/EbBzzwmO0oy+l16fkiRXcRppU/UbW6PUBbIpJNqCjnKcw+DA5UXVDmIv0xXOP34jlnkY1DxnimqMAkgut8gncgdFxO0ap0us6lAgMBAAECgYBzlVpQ/OqMCRVNiYd8ZxicOc6Aaq0skKOFKWsfa6CGZ6KiIMTun3UiXqHeYOm0fcf/MYvcOKvLh/uNRuPQIV3WKAWJ6r+dXQ+LjzmrH4QDMcmkMn0OKxxbe56MASPWka7/08GLiE1FJLDo8DEkBQnlDHqnt4e7BoZSgYVhWv52AQJBAMcr0O7xiB/Ge9aQzqYQJvdQ4JI53pM0lEx5HPzQjbrMjC1flb572js1ajKckkuTX+nxzyTzC3JtfvGCcMqaaoECQQC+E9LoSfZZHpVFCx4ZIh2VgzrGYnelktb6MenILhdji2j9i6ZyAqyg8TjL+W9/kAKnaNAV2j6GF8/bOTX0UGolAkAcUWiFcKXwDqJw4WngRo+jvkYPxFaXC3TCYr3yXByqoIaVtO9vg+CFZpTQ2V4bjLqoYo8XK89G17ai0+8Bf28BAkA+BGvRHKjDJSZg86KrYqUybjHUHraZEFMSKQz1IozBDvB/oXv6QQMgM/RrIQSPI2aqRpl2N9IkoEpSZdVD1KT9AkBtoz4Eg3Nuy1XdCCrTqTMioY0hP74xCcgURpooxmL2xhNUYu6PJr+g4lkaiq8e/2Cr0ZQlps/pEDgaPdHDf3Et
生成的公钥为：
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCT4fFog6N3YSh1vcPOg+A1/OKRwBtNzyHjhwkns28insirLhwN6mshieyakIForOee7msM/efxGwc88JjtKMvpden5IkV3EaaVP1G1uj1AWyKSTago5ynMPgwOVF1Q5iL9MVzj9+I5Z5GNQ8Z4pqjAJILrfIJ3IHRcTtGqdLrOpQIDAQAB
test加密后的内容为：
RgJxG+VSizKgfLnXjsqzTl9h0cUzm460EyHhdL3/qZLNbd6IVcU1Am+OOsbFd9W8GtNhJiCERybgjCucr4c3/EQLXtF8vNHVMFp9ycDW4T+8FMmFQn0f/+oJ7/i9uEoNd9W8nWJcSRHuTw1+rl4Mc7KnmwvdaTV2ZLOxBG6oAK8=

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(2) 前端代码

const privateKey = `MIICdQIBADANBgkqhkiG9w0BAQEFAASCAl8wggJbAgEAAoGBAJPh8WiDo3dhKHW9w86D4DX84pHAG03PIeOHCSezbyKeyKsuHA3qayGJ7JqQgWis557uawz95/EbBzzwmO0oy+l16fkiRXcRppU/UbW6PUBbIpJNqCjnKcw+DA5UXVDmIv0xXOP34jlnkY1DxnimqMAkgut8gncgdFxO0ap0us6lAgMBAAECgYBzlVpQ/OqMCRVNiYd8ZxicOc6Aaq0skKOFKWsfa6CGZ6KiIMTun3UiXqHeYOm0fcf/MYvcOKvLh/uNRuPQIV3WKAWJ6r+dXQ+LjzmrH4QDMcmkMn0OKxxbe56MASPWka7/08GLiE1FJLDo8DEkBQnlDHqnt4e7BoZSgYVhWv52AQJBAMcr0O7xiB/Ge9aQzqYQJvdQ4JI53pM0lEx5HPzQjbrMjC1flb572js1ajKckkuTX+nxzyTzC3JtfvGCcMqaaoECQQC+E9LoSfZZHpVFCx4ZIh2VgzrGYnelktb6MenILhdji2j9i6ZyAqyg8TjL+W9/kAKnaNAV2j6GF8/bOTX0UGolAkAcUWiFcKXwDqJw4WngRo+jvkYPxFaXC3TCYr3yXByqoIaVtO9vg+CFZpTQ2V4bjLqoYo8XK89G17ai0+8Bf28BAkA+BGvRHKjDJSZg86KrYqUybjHUHraZEFMSKQz1IozBDvB/oXv6QQMgM/RrIQSPI2aqRpl2N9IkoEpSZdVD1KT9AkBtoz4Eg3Nuy1XdCCrTqTMioY0hP74xCcgURpooxmL2xhNUYu6PJr+g4lkaiq8e/2Cr0ZQlps/pEDgaPdHDf3Et`;
const cipherText = `RgJxG+VSizKgfLnXjsqzTl9h0cUzm460EyHhdL3/qZLNbd6IVcU1Am+OOsbFd9W8GtNhJiCERybgjCucr4c3/EQLXtF8vNHVMFp9ycDW4T+8FMmFQn0f/+oJ7/i9uEoNd9W8nWJcSRHuTw1+rl4Mc7KnmwvdaTV2ZLOxBG6oAK8=`;
const plainText = CryptoUtils.decryptByRSA(privateKey, cipherText);
console.log(`解密后的内容为：${plainText}`);
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控制台输出：

解密后的内容为：test
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3、前端加签，后端验签

这里我们用前端生成的密钥对做测试。

(1) 前端代码

const {privateKey, publicKey} = CryptoUtils.generateRsaKeyWithPKCS8();
console.log(`生成的私钥为：\n${privateKey}`);
console.log(`生成的公钥为：\n${publicKey}`);

const signature = CryptoUtils.signBySHA256WithRSA(privateKey, "test");
console.log(`生成的签名：\n${signature}`);
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控制台输出如下：

生成的私钥为：
-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----

生成的公钥为：
-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC8cyflPzf5RPgGTszG88fuVq1g
7t9aCpR/o7YeeADxh2Pgpqr4tHVHrkm79t/LZHpveRk8tZEEc/QjAVr71XTWAu/B
PJmgWjCm/hmSlSEnGenqPIJF8RKAe2t/8umvC/0qUBoGiO/CbJ1RiYo3/hmhrX25
fnSEDMSHOoGzWTjPzwIDAQAB
-----END PUBLIC KEY-----

生成的签名：
Q9Mtq3gxi2YJ07FQtbry5zxGljomzKQNewhj10Ba10b3roAAdQUzqd+QyP7rqARdPQgt0ClDgvtaL2TNYLc4URh7E3Kgx8T6pSFlPnU/b3cfCoVRPrr/gJBrsCkbNMITNXpVQpwIYe3P1z+OrCUHuaQR82yCVUz3y43oOiE6qIY=
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(2) 后端代码

String publicKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC8cyflPzf5RPgGTszG88fuVq1g7t9aCpR/o7YeeADxh2Pgpqr4tHVHrkm79t/LZHpveRk8tZEEc/QjAVr71XTWAu/BPJmgWjCm/hmSlSEnGenqPIJF8RKAe2t/8umvC/0qUBoGiO/CbJ1RiYo3/hmhrX25fnSEDMSHOoGzWTjPzwIDAQAB";
String signature = "Q9Mtq3gxi2YJ07FQtbry5zxGljomzKQNewhj10Ba10b3roAAdQUzqd+QyP7rqARdPQgt0ClDgvtaL2TNYLc4URh7E3Kgx8T6pSFlPnU/b3cfCoVRPrr/gJBrsCkbNMITNXpVQpwIYe3P1z+OrCUHuaQR82yCVUz3y43oOiE6qIY=";
boolean isVerified = CryptoUtils.verifyBySHA256WithRSA(publicKey, "test", signature);
System.out.println("是否验签通过：" + isVerified);
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控制台输出：

是否验签通过：true
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4、后端加签，前端验签

这里我们用后端生成的密钥对做测试。

(1) 后端代码

AsymmetricKeyPair keyPair = CryptoUtils.generateAsymmetricKeyPair(Encryption.RSA_ECB_PKCS1);
String privateKey = keyPair.getPrivateKey();
String publicKey = keyPair.getPublicKey();
System.out.println("生成的私钥为：\n" + privateKey);
System.out.println("生成的公钥为：\n" + publicKey);

String signature = CryptoUtils.signBySHA256WithRSA(privateKey, "test");
System.out.println("生成的签名为：\n" + signature);
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控制台输出如下：

生成的私钥为：
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
生成的公钥为：
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCsdYk9Dm8kSgtOsH/ljdb/S00MHevF9W/FOfmQIfUH+5u+x4kLS4Ncvdb9G+9A6/x0T+47hixU5yufjSTHIxjag3wxagkLQN3mptlAAW8B0u+qkRUG0oOUCgKbw3Hzmbalpm8MEgzJCORp2Cm0jtxGWQmAQV86ZWmykAinJhijowIDAQAB
生成的签名为：
JQ2FWaAbHWIkl4uSIxyMNbARFzSNKc7mOtXidm7hCRN85D8DVgZll02DYcWRSnn/ejOOxOrEPF8AcYHWx1repHh/jHcwv2focjF3Yne7NkQ4yGvgILDD2s1BIEfU0EH3tFLMIebyU8V54eMMtjDLQ65LZB6PH+5X8s3F6yAPI70=
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(2) 前端代码

const publicKey = `
      -----BEGIN PUBLIC KEY-----
      MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCsdYk9Dm8kSgtOsH/ljdb/S00MHevF9W/FOfmQIfUH+5u+x4kLS4Ncvdb9G+9A6/x0T+47hixU5yufjSTHIxjag3wxagkLQN3mptlAAW8B0u+qkRUG0oOUCgKbw3Hzmbalpm8MEgzJCORp2Cm0jtxGWQmAQV86ZWmykAinJhijowIDAQAB
      -----END PUBLIC KEY-----`;
const signature = `JQ2FWaAbHWIkl4uSIxyMNbARFzSNKc7mOtXidm7hCRN85D8DVgZll02DYcWRSnn/ejOOxOrEPF8AcYHWx1repHh/jHcwv2focjF3Yne7NkQ4yGvgILDD2s1BIEfU0EH3tFLMIebyU8V54eMMtjDLQ65LZB6PH+5X8s3F6yAPI70=`;
const message = `test`;
const isVerified = CryptoUtils.verifyBySHA256WithRSA(publicKey, signature, message);
console.log(`是否验签通过：${isVerified}`);
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控制台输出如下：

是否验签通过：true
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备注：因为我们在前端解析密钥时读取的是标准pem格式密钥，所以从后端复制过来的公钥一定要加上-----BEGIN PUBLIC KEY-----前缀和-----END PUBLIC KEY-----后缀，否则会报错。