非对称加密

最新推荐文章于 2025-06-03 00:52:25 发布

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最新推荐文章于 2025-06-03 00:52:25 发布

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分类专栏：工具类文章标签： java

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本文介绍了一个使用Java实现的RSA加密解密实用案例，通过随机生成公钥和私钥，并利用这些密钥对指定字符串进行加密及解密操作。文章展示了完整的代码实现过程，包括密钥对生成、公钥加密、私钥解密等步骤。

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package com.hc.utils;

//import org.apache.tomcat.util.codec.binary.Base64;
import org.apache.commons.codec.binary.Base64;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import java.nio.charset.StandardCharsets;
import java.security.*;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;
 
/**
 * @Author: hc
 * @Description:
 * @Date: 2021/04/18 9:05
 */
public class RSATestUtils {
 
    public static void main(String[] args) {
        //生成公钥和私钥
        Map<Integer,String> keyMap = genKeyPair();
        //加密字符串
        String content = "我是加密内容，我是加密内容//、/。/、；|、\\//\\/#@#$$%%^&**%$$%&%#*@#$";
        System.out.println("加密前内容:"+content);
        System.out.println("随机生成的公钥为:" + keyMap.get(0));
        System.out.println("随机生成的私钥为:" + keyMap.get(1));
        String messageEn = encrypt(content, keyMap.get(0));
        System.out.println("加密后的内容为:" + messageEn);
        String messageDe = decrypt(messageEn, keyMap.get(1));
        System.out.println("还原后的内容为:" + messageDe);


        /*String publicKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCnMdfT0F8Gu2P6XcsaolNPY9bXHYStT0x7jxPBi1j6dVL+8/6lOmHDZFwweTqt6cPbC6T3Yqh9zgzDu4kn/XNEQfFs0tF3uWAx/kzD2h47h9N2HgUIFUhdQ/94BFrrmBSoGJlyf3p9KOA7wmgxgsRWS8ejAsf/9jjYo0bWN4PIlQIDAQAB";
        String privateKey = "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";
        String messageEn = encrypt(content, publicKey);
        System.out.println("加密后的内容为:" + messageEn);
        String messageDe = decrypt(messageEn, privateKey);
        System.out.println("还原后的内容为:" + messageDe);*/
    }
 
    //随机生成密钥对
    public static Map genKeyPair() {
        // KeyPairGenerator类用于生成公钥和私钥对，基于RSA算法生成对象
        KeyPairGenerator keyPairGen = null;
 
        try {
            keyPairGen = KeyPairGenerator.getInstance("RSA");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
 
        // 初始化密钥对生成器，密钥大小为96-1024位
        assert keyPairGen != null;
        keyPairGen.initialize(1024, new SecureRandom());
        // 生成一个密钥对，保存在keyPair中
        KeyPair keyPair = keyPairGen.generateKeyPair();
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();   // 得到私钥
        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();  // 得到公钥
        String publicKeyString = new String(Base64.encodeBase64(publicKey.getEncoded()));
        // 得到私钥字符串
        String privateKeyString = new String(Base64.encodeBase64((privateKey.getEncoded())));
        // 将公钥和私钥保存到Map
        Map<Integer, String> keyMap = new HashMap<>();
        keyMap.put(0, publicKeyString);  //0表示公钥
        keyMap.put(1, privateKeyString);  //1表示私钥
        return keyMap;
    }
 
    /** RSA公钥加密
     * @param str  加密字符串
     * @param publicKey  公钥
     * @return  密文
     */
    public static String encrypt(String str, String publicKey) {
        //base64编码的公钥
        byte[] decoded = Base64.decodeBase64(publicKey);
        RSAPublicKey pubKey = null;
        String outStr = null;
 
        try {
            pubKey = (RSAPublicKey) KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(decoded));
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.ENCRYPT_MODE, pubKey);
            outStr = Base64.encodeBase64String(cipher.doFinal(str.getBytes(StandardCharsets.UTF_8)));
        } catch (InvalidKeySpecException | BadPaddingException | IllegalBlockSizeException | InvalidKeyException | NoSuchPaddingException | NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        //RSA加密
        return outStr;
    }
 
    /**  RSA私钥解密
     * @param str   加密字符串
     * @param privateKey  私钥
     * @return  铭文
     */
    public static String decrypt(String str, String privateKey) {
        //64位解码加密后的字符串
        byte[] inputByte = Base64.decodeBase64(str.getBytes(StandardCharsets.UTF_8));
        //base64编码的私钥
        byte[] decoded = Base64.decodeBase64(privateKey);
        RSAPrivateKey priKey = null;
        //RSA解密
        Cipher cipher = null;
        String outStr = null;
 
        try {
            priKey = (RSAPrivateKey) KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(decoded));
            cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.DECRYPT_MODE, priKey);
            outStr = new String(cipher.doFinal(inputByte));
        } catch (InvalidKeySpecException | NoSuchAlgorithmException | NoSuchPaddingException | BadPaddingException | IllegalBlockSizeException | InvalidKeyException e) {
            e.printStackTrace();
        }
        return outStr;
    }
 
 
}