Java实现RSA 加密解密签名验签的工具类复制粘贴直接用

Posted 2022-03-26 小志的博客

目录

• • 一、pom.xml文件中需要引入如下依赖
  • 二、RSA 加解密、签名、验签的工具类
  • 三、RSA 加解密、签名、验签的测试类
  • 四、输出结果如下

一、pom.xml文件中需要引入如下依赖

  <dependency>
       <groupId>commons-codec</groupId>
       <artifactId>commons-codec</artifactId>
       <version>1.10</version>
  </dependency>

二、RSA 加解密、签名、验签的工具类

package com.rf.data_structure_algorithm.algorithm;
import java.io.ByteArrayOutputStream;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import javax.crypto.Cipher;
import org.apache.commons.codec.binary.Base64;

/**
 * @description: RSA 加解密、签名、验签工具类
 * @author: xiaozhi
 * @create: 2020-12-04 21:15
 */
public class RSA 

    /**
     * RSA最大加密明文大小
     */
    private static final int MAX_ENCRYPT_BLOCK = 64;

    /**
     * RSA最大解密密文大小
     */
    private static final int MAX_DECRYPT_BLOCK = 75;

    /**
     * 获取密钥对
     *
     * @return 密钥对
     */
    public static KeyPair getKeyPair() throws Exception 
        KeyPairGenerator generator = KeyPairGenerator.getInstance("RSA");
        generator.initialize(512);
        return generator.generateKeyPair();
    

    /**
     * 获取私钥
     *
     * @param privateKey 私钥字符串
     * @return
     */
    public static PrivateKey getPrivateKey(String privateKey) throws Exception 
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        byte[] decodedKey = Base64.decodeBase64(privateKey.getBytes());
        PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(decodedKey);
        return keyFactory.generatePrivate(keySpec);
    

    /**
     * 获取公钥
     *
     * @param publicKey 公钥字符串
     * @return
     */
    public static PublicKey getPublicKey(String publicKey) throws Exception 
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        byte[] decodedKey = Base64.decodeBase64(publicKey.getBytes());
        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(decodedKey);
        return keyFactory.generatePublic(keySpec);
    

    /**
     * RSA加密
     *
     * @param data 待加密数据
     * @param publicKey 公钥
     * @return
     */
    public static String encrypt(String data, PublicKey publicKey) throws Exception 
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);
        int inputLen = data.getBytes().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.getBytes(), offset, MAX_ENCRYPT_BLOCK);
             else 
                cache = cipher.doFinal(data.getBytes(), offset, inputLen - offset);
            
            out.write(cache, 0, cache.length);
            i++;
            offset = i * MAX_ENCRYPT_BLOCK;
        
        byte[] encryptedData = out.toByteArray();
        out.close();
        // 获取加密内容使用base64进行编码,并以UTF-8为标准转化成字符串
        // 加密后的字符串
        return new String(Base64.encodeBase64String(encryptedData));
    

    /**
     * RSA解密
     *
     * @param data 待解密数据
     * @param privateKey 私钥
     * @return
     */
    public static String decrypt(String data, PrivateKey privateKey) throws Exception 
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.DECRYPT_MODE, privateKey);
        byte[] dataBytes = Base64.decodeBase64(data);
        int inputLen = dataBytes.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(dataBytes, offset, MAX_DECRYPT_BLOCK);
             else 
                cache = cipher.doFinal(dataBytes, offset, inputLen - offset);
            
            out.write(cache, 0, cache.length);
            i++;
            offset = i * MAX_DECRYPT_BLOCK;
        
        byte[] decryptedData = out.toByteArray();
        out.close();
        // 解密后的内容
        return new String(decryptedData, "UTF-8");
    

    /**
     * 签名
     *
     * @param data 待签名数据
     * @param privateKey 私钥
     * @return 签名
     */
    public static String sign(String data, PrivateKey privateKey) throws Exception 
        byte[] keyBytes = privateKey.getEncoded();
        PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        PrivateKey key = keyFactory.generatePrivate(keySpec);
        Signature signature = Signature.getInstance("MD5withRSA");
        signature.initSign(key);
        signature.update(data.getBytes());
        return new String(Base64.encodeBase64(signature.sign()));
    

    /**
     * 验签
     *
     * @param srcData 原始字符串
     * @param publicKey 公钥
     * @param sign 签名
     * @return 是否验签通过
     */
    public static boolean verify(String srcData, PublicKey publicKey, String sign) throws Exception 
        byte[] keyBytes = publicKey.getEncoded();
        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        PublicKey key = keyFactory.generatePublic(keySpec);
        Signature signature = Signature.getInstance("MD5withRSA");
        signature.initVerify(key);
        signature.update(srcData.getBytes());
        return signature.verify(Base64.decodeBase64(sign.getBytes()));
    

三、RSA 加解密、签名、验签的测试类

package com.rf.data_structure_algorithm.algorithm;

import org.apache.commons.codec.binary.Base64;

import java.security.KeyPair;
/**
 * @description: RSA 加解密、签名、验签 测试类
 * @author: xiaozhi
 * @create: 2020-12-04 22:12
 */
public class TestRSA 
    public static void main(String[] args) 
        RSA rsa=new RSA();
        try 
            // 生成密钥对
            KeyPair keyPair = rsa.getKeyPair();
            String privateKey = new String(Base64.encodeBase64(keyPair.getPrivate().getEncoded()));
            String publicKey = new String(Base64.encodeBase64(keyPair.getPublic().getEncoded()));
            System.out.println("私钥:" + privateKey);
            System.out.println("公钥:" + publicKey);
            // RSA加密 待加密的文字内容
            String data = "123456";
            String encryptData = rsa.encrypt(data, rsa.getPublicKey(publicKey));
            System.out.println("加密前内容:" + data);
            System.out.println("加密后内容:" + encryptData);
            // RSA解密
            String decryptData = rsa.decrypt(encryptData, rsa.getPrivateKey(privateKey));
            System.out.println("解密后内容:" + decryptData);

            // RSA签名
            String sign = rsa.sign(data, rsa.getPrivateKey(privateKey));
            System.out.println("签名结果："+sign);
            // RSA验签
            boolean result = rsa.verify(data, rsa.getPublicKey(publicKey), sign);
            System.out.print("验签结果:" + result);
         catch (Exception e) 
            e.printStackTrace();
            System.out.print("加解密异常");
        
    

四、输出结果如下