证书加签、验签、加密、解密Demo

package sslSocket;
import javax.crypto.Cipher;
import java.io.FileInputStream;
import java.security.*;
import java.security.cert.Certificate;
import java.security.cert.X509Certificate;
import java.util.Base64;

/**
 * @ClassName:          证书获取公钥、私钥、加密、解密、加签、验签示例
 * @Description:
 * @author:
 * @date: 2020年07月21日 14:56
 * @Copyright:
 */
public class KeyStoreDemo {
    public static void main(String[] args) throws Exception {

//        keyTool 工具制作使用下面工具
//        1.制作保存公钥信息和私钥信息的jks文件
//        keytool -genkeypair -alias mtlks -keyalg RSA -keypass 123456 -keystore E:\自制证书\mtlks.jks -validity 3650 -storepass 123456
//        2.将jks文件转换为行业标准PKCS12格式
//        keytool -importkeystore -srckeystore E:\自制证书\mtlks.jks -destkeystore E:\自制证书\mtlks.jks -deststoretype pkcs12
//        3.导出只包括公钥信息的cer文件
//        keytool -export -alias mtlks -keystore E:\自制证书\mtlks.jks -storepass 123456 -file E:\自制证书\mtlks.cer
//        4.制作keystore公钥证书
//        keytool -import -alias mtltks -file E:\自制证书\mtlks.cer -keystore E:\自制证书\mtlt.jks -storepass 654321


        //在线制作
//        https://myssl.com/

        KeyStoreDemo demo=new KeyStoreDemo();
        KeyStore keyStore = demo.loadKeyStore("E:\\自制证书\\mtlks.pfx", "123456");//自制的pfx证书
        System.out.println("公钥："+demo.getPublicKeyStr(keyStore,"mtlks"));
        System.out.println("私钥："+demo.getPrivateKeyStr(keyStore,"mtlks","123456"));
        System.out.println("-------------------------");
        KeyStore keyStore2 = demo.loadKeyStore("E:\\自制证书\\mtlt.jks", "654321");//自制的公钥证书
        System.out.println("公钥："+demo.getPublicKeyStr(keyStore2,"mtltks"));
        //System.out.println("私钥："+demo.getPrivateKeyStr(keyStore2,"mtltks","123456"));//不带私钥，所以没有私钥


        //待加密数据
        String data="17788662514莫天龙大囧看几哈出红堵车好e上大囧的那件黄卡件档卡41.\\=--\\/./,nj户丢刷车汉黄炯A款韩打算好久as当";

        //私钥加密
        System.out.println("---------------------\n\n\n");
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE,keyStore.getKey("mtlks", "123456".toCharArray()));
        //如果报错，javax.crypto.IllegalBlockSizeException: Data must not be longer than 245 bytes，加密数据过长，请采用分段加密策略
        byte[] bytes = cipher.doFinal(data.getBytes("UTF-8"));
        System.out.println("私钥加密结果："+Base64.getEncoder().encodeToString(bytes));

        //公钥解密
        Cipher c=Cipher.getInstance("RSA");
        c.init(Cipher.DECRYPT_MODE,keyStore2.getCertificate("mtltks").getPublicKey());
        byte[] bys = c.doFinal(bytes);
        System.out.println("公钥解析结果："+new String(bys,"UTF-8"));



        System.out.println("\n\n\n####################################\n\n\n");


        //公钥加密
        Cipher cc1=Cipher.getInstance("RSA");
        cc1.init(Cipher.ENCRYPT_MODE,keyStore2.getCertificate("mtltks").getPublicKey());
        byte[] bb1 = cc1.doFinal(data.getBytes("UTF-8"));
        System.out.println("公钥加密结果："+Base64.getEncoder().encodeToString(bb1));
        //私钥解密

        Cipher cc2=Cipher.getInstance("RSA");
        cc2.init(Cipher.DECRYPT_MODE,keyStore.getKey("mtlks","123456".toCharArray()));
        byte[] bb2 = cc2.doFinal(bb1);
        System.out.println("私钥解密结果："+new String(bb2,"UTF-8"));


        System.out.println("-----------------------\n\n\n");
        String str="1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据1111111111111111111111222222222222222222222222222222,/.,kofksd;lf,s51211fsj加签数据";
        System.out.println(str.getBytes("UTF-8").length);
        //私钥加签
        PrivateKey privateKey = ((PrivateKey) keyStore.getKey("mtlks", "123456".toCharArray()));
        //根据证书签名算法名称获取签名
        System.out.println("签名算法："+((X509Certificate) keyStore.getCertificate("mtlks")).getSigAlgName());
        Signature signature=Signature.getInstance(((X509Certificate) keyStore.getCertificate("mtlks")).getSigAlgName());
        signature.initSign(privateKey);
        signature.update(str.getBytes("UTF-8"));
        byte[] sign = signature.sign();
        System.out.println("加签后的签名："+Base64.getEncoder().encodeToString(sign));

        //验签
        Signature ss=Signature.getInstance(((X509Certificate) keyStore2.getCertificate("mtltks")).getSigAlgName());
        ss.initVerify(keyStore2.getCertificate("mtltks").getPublicKey());
        ss.update(str.getBytes("UTF-8"));
        System.out.println("验签结果："+ss.verify(sign));
    }


    
    /** 
    * @Description: 加载keyStore文件
    * @Param:  
    * @return:
    * @Author: MoTianLong 
    * @Exception 
    * @Date: 2020\7\21 0021 
    */ 
    public KeyStore loadKeyStore(String path,String password){
        try(FileInputStream fileInputStream=new FileInputStream(path)){
            KeyStore keyStore=KeyStore.getInstance("JKS");
            keyStore.load(fileInputStream, password.toCharArray());
            return keyStore;
        } catch (Exception e) {
            throw new RuntimeException("加载keyStore文件失败！",e);
        }
    }
    
    /**
    * @Description: 获取公钥字符串（base64编码格式）
    * @Param:  
    * @return:
    * @Author: MoTianLong
    * @Exception
    * @Date: 2020\7\21 0021
    */
    public String getPublicKeyStr(KeyStore keyStore,String alias){
        try {
            Certificate certificate = keyStore.getCertificate(alias);
            PublicKey publicKey = certificate.getPublicKey();
            return Base64.getEncoder().encodeToString(publicKey.getEncoded());
        } catch (Exception e) {
            throw new RuntimeException("获取公钥信息失败！",e);
        }
    }

    /**
    * @Description:  获取私钥字符串（base64编码格式）
    * @Param:
    * @return:
    * @Author: MoTianLong
    * @Exception
    * @Date: 2020\7\21 0021
    */
    public String getPrivateKeyStr(KeyStore keyStore,String alias,String password){
        try {
            Key key = keyStore.getKey(alias, password.toCharArray());
            return Base64.getEncoder().encodeToString(key.getEncoded());
        } catch (Exception e) {
            throw new RuntimeException("获取私钥信息失败！",e);
        }
    }
}

参考：https://www.cnblogs.com/leslies2/p/7442956.html#p1