Java SM2加密相关实现与简单原理

        首先我们应该了解SM2加密的主要用途:数字签名、密钥交换和公钥加密等应用。以下为SM2加密的简单原理:

  1. 密钥生成:首先,生成一对公钥和私钥。公钥用于加密和验证签名,私钥用于解密和生成签名。

  2. 加密过程:

    • 随机选择一个临时的非零整数k,计算椭圆曲线点C = k * G,其中G是曲线上的基点。
    • 将明文数据转换为椭圆曲线上的点M。
    • 计算椭圆曲线点C1 = k * G。
    • 计算椭圆曲线点S = (h + x) * C1,其中h是哈希值,x是私钥。
    • 将明文数据与S进行异或运算,得到密文C2。
    • 将C1和C2组合在一起作为最终的加密结果。
  3. 解密过程:

    • 使用私钥x计算椭圆曲线点C1' = x * C1。
    • 从C1'中提取出明文数据M'。
    • 将M'与密文C2进行异或运算,得到原始的明文数据。

        我们要了解对于同一个公钥和同一个数据,多次加密的密文是不相同的!!!

import cn.hutool.json.JSONObject;
import com.alibaba.fastjson.JSON;
import org.bouncycastle.asn1.gm.GMNamedCurves;
import org.bouncycastle.asn1.x9.X9ECParameters;
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.engines.SM2Engine;
import org.bouncycastle.crypto.params.ECDomainParameters;
import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
import org.bouncycastle.crypto.params.ECPublicKeyParameters;
import org.bouncycastle.crypto.params.ParametersWithRandom;
import org.bouncycastle.crypto.signers.SM2Signer;
import org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPrivateKey;
import org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPublicKey;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.jce.spec.ECParameterSpec;
import org.bouncycastle.jce.spec.ECPrivateKeySpec;
import org.bouncycastle.math.ec.ECPoint;
import org.bouncycastle.util.encoders.Hex;

import java.math.BigInteger;
import java.nio.charset.StandardCharsets;
import java.security.*;
import java.security.spec.ECGenParameterSpec;
import java.util.Base64;

/**
 * SM2工具类
 * @author van
 */
public class SM2Util {

    /**
     * 生成 SM2 公私钥对
     *
     * @return
     * @throws NoSuchAlgorithmException
     * @throws InvalidAlgorithmParameterException
     */
    public static KeyPair geneSM2KeyPair() throws NoSuchAlgorithmException, InvalidAlgorithmParameterException {
        final ECGenParameterSpec sm2Spec = new ECGenParameterSpec("sm2p256v1");
        // 获取一个椭圆曲线类型的密钥对生成器
        final KeyPairGenerator kpg = KeyPairGenerator.getInstance("EC", new BouncyCastleProvider());
        // 产生随机数
        SecureRandom secureRandom = new SecureRandom();
        // 使用SM2参数初始化生成器
        kpg.initialize(sm2Spec, secureRandom);
        // 获取密钥对
        KeyPair keyPair = kpg.generateKeyPair();
        return keyPair;
    }

    /**
     * 生产hex秘钥对
     */
    public static void geneSM2HexKeyPair(){
        try {
            KeyPair keyPair = geneSM2KeyPair();
            PrivateKey privateKey = keyPair.getPrivate();
            PublicKey publicKey = keyPair.getPublic();
            System.out.println("========  EC X Y keyPair    ========");
            System.out.println(privateKey);
            System.out.println(publicKey);
            System.out.println("========  hex keyPair       ========");
            System.out.println("hex priKey: " + getPriKeyHexString(privateKey));
            System.out.println("hex pubKey: " + getPubKeyHexString(publicKey));
            System.out.println("========  base64 keyPair    ========");
            System.out.println("base64 priKey: " + new String(Base64.getEncoder().encode(privateKey.getEncoded())));
            System.out.println("base64 pubKey: " + new String(Base64.getEncoder().encode(publicKey.getEncoded())));
            System.out.println("========  generate finished ========");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    /**
     * 获取私钥(16进制字符串,头部不带00长度共64)
     *
     * @param privateKey 私钥PrivateKey型
     * @return
     */
    public static String getPriKeyHexString(PrivateKey privateKey) {
        // OK
//        BCECPrivateKey s=(BCECPrivateKey)privateKey;
//        String priKeyHexString = Hex.toHexString(s.getD().toByteArray());
//        if(null!= priKeyHexString && priKeyHexString.length()==66 && "00".equals(priKeyHexString.substring(0,2))){
//            return priKeyHexString.substring(2);
//        }
        // OK
        BCECPrivateKey key = (BCECPrivateKey) privateKey;
        BigInteger intPrivateKey = key.getD();
        String priKeyHexString = intPrivateKey.toString(16);
        return priKeyHexString;
    }
    /**
     * 获取私钥 base64字符串
     *
     * @param privateKey 私钥PrivateKey型
     * @return
     */
    public static String getPriKeyBase64String(PrivateKey privateKey) {
        return new String(Base64.getEncoder().encode(privateKey.getEncoded()));
    }

    /**
     * 获取公钥(16进制字符串,头部带04长度共130)
     *
     * @param publicKey 公钥PublicKey型
     * @return
     */
    public static String getPubKeyHexString(PublicKey publicKey) {
        BCECPublicKey key = (BCECPublicKey) publicKey;
        return Hex.toHexString(key.getQ().getEncoded(false));
    }
    /**
     * 获取公钥 base64字符串
     *
     * @param publicKey 公钥PublicKey型
     * @return
     */
    public static String getPubKeyBase64String(PublicKey publicKey) {
        return new String(Base64.getEncoder().encode(publicKey.getEncoded()));
    }

    /**
     * SM2加密算法
     *
     * @param publicKey 公钥
     * @param data      明文数据
     * @return
     */
    public static String encrypt(String data, PublicKey publicKey) {
        return encrypt(data.getBytes(StandardCharsets.UTF_8), publicKey);
    }

    public static String encrypt(byte[] data, PublicKey publicKey) {
        BCECPublicKey key = (BCECPublicKey) publicKey;
        return encrypt(data, Hex.toHexString(key.getQ().getEncoded(false)));
    }

    public static String encrypt(String data, String pubKeyHexString) {
        return encrypt(data.getBytes(StandardCharsets.UTF_8), pubKeyHexString);
    }

    /**
     * SM2加密算法
     *
     * @param pubKeyHexString 公钥(16进制字符串)
     * @param data            明文数据
     * @return hex字符串
     */
    public static String encrypt(byte[] data, String pubKeyHexString) {
        // 获取一条SM2曲线参数
        X9ECParameters sm2ECParameters = GMNamedCurves.getByName("sm2p256v1");
        // 构造ECC算法参数,曲线方程、椭圆曲线G点、大整数N
        ECDomainParameters domainParameters = new ECDomainParameters(sm2ECParameters.getCurve(), sm2ECParameters.getG(), sm2ECParameters.getN());
        //提取公钥点
        ECPoint pukPoint = sm2ECParameters.getCurve().decodePoint(Hex.decode(pubKeyHexString));
        // 公钥前面的02或者03表示是压缩公钥,04表示未压缩公钥, 04的时候,可以去掉前面的04
        ECPublicKeyParameters publicKeyParameters = new ECPublicKeyParameters(pukPoint, domainParameters);

        SM2Engine sm2Engine = new SM2Engine(SM2Engine.Mode.C1C3C2);
        // 设置sm2为加密模式
        sm2Engine.init(true, new ParametersWithRandom(publicKeyParameters, new SecureRandom()));

        byte[] arrayOfBytes = null;
        try {
            arrayOfBytes = sm2Engine.processBlock(data, 0, data.length);
        } catch (Exception e) {
            System.out.println("SM2加密时出现异常:" + e.getMessage());
        }
        return Hex.toHexString(arrayOfBytes);

    }

    /**
     * SM2解密算法
     * @param cipherData    hex格式密文
     * @param privateKey    密钥PrivateKey型
     * @return              明文
     */
    public static String decrypt(String cipherData, PrivateKey privateKey) {
        return decrypt(Hex.decode(cipherData), privateKey);
    }

    public static String decrypt(byte[] cipherData, PrivateKey privateKey) {
        BCECPrivateKey key = (BCECPrivateKey) privateKey;
        return decrypt(cipherData, Hex.toHexString(key.getD().toByteArray()));
    }

    public static String decrypt(String cipherData, String priKeyHexString) {
        // 使用BC库加解密时密文以04开头,传入的密文前面没有04则补上
        if (!cipherData.startsWith("04")) {
            cipherData = "04" + cipherData;
        }
        return decrypt(Hex.decode(cipherData), priKeyHexString);
    }

    /**
     * SM2解密算法
     *
     * @param cipherData      密文数据
     * @param priKeyHexString 私钥(16进制字符串)
     * @return
     */
    public static String decrypt(byte[] cipherData, String priKeyHexString) {
        //获取一条SM2曲线参数
        X9ECParameters sm2ECParameters = GMNamedCurves.getByName("sm2p256v1");
        //构造domain参数
        ECDomainParameters domainParameters = new ECDomainParameters(sm2ECParameters.getCurve(), sm2ECParameters.getG(), sm2ECParameters.getN());

        BigInteger privateKeyD = new BigInteger(priKeyHexString, 16);
        ECPrivateKeyParameters privateKeyParameters = new ECPrivateKeyParameters(privateKeyD, domainParameters);

        SM2Engine sm2Engine = new SM2Engine(SM2Engine.Mode.C1C3C2);
        // 设置sm2为解密模式
        sm2Engine.init(false, privateKeyParameters);

        String result = "";
        try {
            byte[] arrayOfBytes = sm2Engine.processBlock(cipherData, 0, cipherData.length);
            return new String(arrayOfBytes);
        } catch (Exception e) {
            System.out.println("SM2解密时出现异常:" + e.getMessage());
        }
        return result;
    }

    /**
     * @param data
     * @param priKeyHexString hex私钥,长度64
     * @return hex格式签名值
     * @throws Exception
     */
    public static String sign(String data, String priKeyHexString) throws Exception {
        return sign(data.getBytes(StandardCharsets.UTF_8), priKeyHexString);
    }

    /**
     * 签名
     * @param data              原始数据,字节数组
     * @param priKeyHexString   hex私钥,64长度
     * @return                  Hex字符串
     * @throws Exception
     */
    public static String sign(byte[] data, String priKeyHexString) throws Exception {
        String signValue = null;
        SM2Signer signer = new SM2Signer();
        X9ECParameters sm2ECParameters = GMNamedCurves.getByName("sm2p256v1");
        //构造domain参数
        ECDomainParameters domainParameters = new ECDomainParameters(sm2ECParameters.getCurve(), sm2ECParameters.getG(), sm2ECParameters.getN());
        CipherParameters param = new ParametersWithRandom(new ECPrivateKeyParameters(new BigInteger(priKeyHexString, 16), domainParameters));
        signer.init(true, param);
        signer.update(data, 0, data.length);
        signValue = Hex.toHexString(signer.generateSignature());
        return signValue;
    }

    /**
     * 验签
     * @param data                  原始数据
     * @param signValue             原始签名值(hex型)
     * @param publicKeyHexString    hex130长度公钥
     * @return                      ture or false
     * @throws Exception
     */
    public static boolean verify(String data, String signValue, String publicKeyHexString) throws Exception {
        return verify(data.getBytes(StandardCharsets.UTF_8), Hex.decode(signValue), publicKeyHexString);
    }

    /**
     * 验签
     * @param data                  原始数据字节数组
     * @param sign                  字节数组()
     * @param publicKeyHexString    hex130长度公钥
     * @return                      true or false
     * @throws Exception
     */
    public static boolean verify(byte[] data, byte[] sign, String publicKeyHexString) throws Exception {
        SM2Signer signer = new SM2Signer();
        X9ECParameters sm2ECParameters = GMNamedCurves.getByName("sm2p256v1");
        //构造domain参数
        ECDomainParameters domainParameters = new ECDomainParameters(sm2ECParameters.getCurve(), sm2ECParameters.getG(), sm2ECParameters.getN());
        if (publicKeyHexString.length() == 128) {
            publicKeyHexString = "04" + publicKeyHexString;
        }
        ECPoint ecPoint = sm2ECParameters.getCurve().decodePoint(Hex.decode(publicKeyHexString));
        CipherParameters param = new ECPublicKeyParameters(ecPoint, domainParameters);
        signer.init(false, param);
        signer.update(data, 0, data.length);
        return signer.verifySignature(sign);
    }

    /**
     * 私钥生成公钥
     * @param priKeyHexString 私钥Hex格式,必须64位
     * @return 公钥Hex格式,04开头,130位
     * @throws Exception 例如:
     *                   04181db7fe400641115c0dec08e23d8ddb94c5999f2fb6efd03030780142e077a63eb4d47947ef5baee7f40fec2c29181d2a714d9c6cba87b582f252a4e3e9a9f8
     *                   11d0a44d47449d48d614f753ded6b06af76033b9c3a2af2b8b2239374ccbce3a
     */
    public static String getPubKeyByPriKey(String priKeyHexString) throws Exception {
        if (priKeyHexString == null || priKeyHexString.length() != 64) {
            System.err.println("priKey 必须是Hex 64位格式,例如:11d0a44d47449d48d614f753ded6b06af76033b9c3a2af2b8b2239374ccbce3a");
            return "";
        }
        String pubKeyHexString = null;
        X9ECParameters sm2ECParameters = GMNamedCurves.getByName("sm2p256v1");
        //构造domain参数
        BigInteger privateKeyD = new BigInteger(priKeyHexString, 16);

        ECParameterSpec ecParameterSpec = new ECParameterSpec(sm2ECParameters.getCurve(), sm2ECParameters.getG(), sm2ECParameters.getN());
        ECPrivateKeySpec ecPrivateKeySpec = new ECPrivateKeySpec(privateKeyD, ecParameterSpec);
        PrivateKey privateKey = null;
        privateKey = KeyFactory.getInstance("EC", new BouncyCastleProvider()).generatePrivate(ecPrivateKeySpec);

        // 临时解决办法
        String pointString = privateKey.toString();
//        System.out.println(pointString);
        String pointString_X = pointString.substring(pointString.indexOf("X: ") + "X: ".length(), pointString.indexOf("Y: ")).trim();
        String pointString_Y = pointString.substring(pointString.indexOf("Y: ") + "Y: ".length()).trim();
//        System.out.println(pointString_X);
//        System.out.println(pointString_Y);

        pubKeyHexString = "04" + pointString_X + pointString_Y;
        return pubKeyHexString;

    }

    // 将字符串转换为十六进制字符串
    public static String stringToHex(String str) {
        StringBuilder hexString = new StringBuilder();

        for (char ch : str.toCharArray()) {
            hexString.append(Integer.toHexString((int) ch));
        }

        return hexString.toString();
    }

    public static void main(String[] args) throws Exception {
        System.out.println("======  sm2utils test  ======");

        JSONObject jsonObject = new JSONObject();
        jsonObject.put("username","jsdxzx");
        jsonObject.put("password","1");
        jsonObject.put("clientId","jsdxzx");
        jsonObject.put("grantType","password_credentials");
        jsonObject.put("passwordEncode",true);
        String jsonString = JSON.toJSONString(jsonObject);

        String M = jsonString;
        System.out.println("mingwen\t" + M);

        System.out.println("begin 开始生成密钥对>>>");
        KeyPair keyPair = geneSM2KeyPair();

        PublicKey publicKey = keyPair.getPublic();
        String pubKeyHexString = getPubKeyHexString(publicKey);
        System.out.println("publicKey\t" + pubKeyHexString);

        PrivateKey privateKey = keyPair.getPrivate();
        String priKeyHexString = getPriKeyHexString(privateKey);
        System.out.println("privateKey\t" + priKeyHexString);
        System.out.println("end   结束生成密钥对>>>");

        priKeyHexString="4f0341e5977b175e0ec0e1fdefd2799b13dd25c51716133ef42ba76c0edd973d"; //1
        pubKeyHexString="04e523210b3407464839723558e0d82765b9e2cac9491bd86c99c89b9fc43fbe9a94395ee3138dbc4ae43daa8fe01fd512de8568102e34c66989eb2b306611b518"; //1
        System.out.println("publicKey\t" + pubKeyHexString);

        String cipherData = encrypt(M, pubKeyHexString);
        System.out.println("miwen\t" + cipherData);

        String text = decrypt(cipherData, priKeyHexString);
        System.out.println("jiemi\t" + text);

        String sign = sign(M, priKeyHexString);
        System.out.println("signvalue\t" + sign);
        sign="304402204bbd4b026f58f1e072c2ab1f736a730ed5c2f6773ef4855df5e87f9ea54f14be02205e9b6146b5273e6f37fe6d9d8f059bc46f7042a10da224130a4e0ba8619d967c";

        boolean verifyResult = verify(M, sign, pubKeyHexString);
        System.out.println("verifyResult\t" + verifyResult);

    }
}

你可能感兴趣的:(java)