rsa加密解密

package com.hcp.config.rsa;

import org.bouncycastle.util.encoders.Base64;
import javax.crypto.Cipher;
import java.security.*;
public class RsaUtil {

    /**
     * 公钥
     */
    private static PublicKey publicKey;
    /**
     * 私钥
     */
    private static PrivateKey privateKey;
    /**
     * 编码
     */
    private static final String CHARSET = "UTF-8";

    /**
     * 初始化
     */
    static void init() throws NoSuchAlgorithmException {
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
        // 设置密钥长度
        keyPairGenerator.initialize(2048);
        KeyPair keyPair = keyPairGenerator.generateKeyPair();
        publicKey = keyPair.getPublic();
        privateKey = keyPair.getPrivate();
    }

    /**
     * 加密
     */
    public static String encrypt(String plaintext, PublicKey publicKey) throws Exception {
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);
        byte[] encryptedBytes = cipher.doFinal(plaintext.getBytes(CHARSET));
        return new String(Base64.encode(encryptedBytes), CHARSET);
    }

    /**
     * 解密
     */
    public static String decrypt(String ciphertext, PrivateKey privateKey) throws Exception {
        byte[] encryptedBytes = Base64.decode(ciphertext.getBytes(CHARSET));
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.DECRYPT_MODE, privateKey);
        byte[] decryptedBytes = cipher.doFinal(encryptedBytes);
        return new String(decryptedBytes, CHARSET);
    }

    public static void main(String[] args) throws Exception {
        RsaUtil.init();
        String plaintext = "Hello, World!";
        String ciphertext = RsaUtil.encrypt(plaintext, RsaUtil.publicKey);
        System.out.println(ciphertext);
        String decrypt = RsaUtil.decrypt(ciphertext, RsaUtil.privateKey);
        System.out.println(decrypt);
    }

}