JAVA bouncycastle实现SM2算法（国密2）

JAVA bouncycastle实现SM2算法（国密2）

package com.blcase.common.utils.sm;
import org.bouncycastle.asn1.gm.GMNamedCurves;
import org.bouncycastle.asn1.x9.X9ECParameters;
import org.bouncycastle.crypto.engines.SM2Engine;
import org.bouncycastle.crypto.params.*;
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.math.ec.ECPoint;
import org.bouncycastle.util.encoders.Hex;

import org.bouncycastle.jce.provider.BouncyCastleProvider;

import java.math.BigInteger;
import java.security.*;
import java.security.spec.ECGenParameterSpec;


//
public class SM2Util {

    /**
     * SM2加密算法
     * @param publicKey     公钥
     * @param data          明文数据
     * @return
     */
    public String encrypt(String publicKey, String data) {


        // 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(publicKey));
        // 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 {
            byte[] in = data.getBytes();
            arrayOfBytes = sm2Engine.processBlock(in, 0, in.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 privateKey        私钥
     * @param cipherData        密文数据
     * @return
     */
    public String decrypt(String privateKey, String cipherData) {

        // 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;
        }
        byte[] cipherDataByte = Hex.decode(cipherData);

        //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(privateKey, 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(cipherDataByte, 0, cipherDataByte.length);
            return new String(arrayOfBytes);
        } catch (Exception e) {
            System.out.println("SM2解密时出现异常:"+e.getMessage());
        }
        return result;
        
    }


    public static void main(String[] args) throws NoSuchAlgorithmException, InvalidAlgorithmParameterException {
    
        String M="encryption standard";
        SM2Util sm2 = new SM2Util();
        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());
        // 使用SM2参数初始化生成器
        kpg.initialize(sm2Spec);
        // 获取密钥对
        KeyPair keyPair = kpg.generateKeyPair();
        PublicKey publicKey = keyPair.getPublic();
        BCECPublicKey p=(BCECPublicKey)publicKey;
        System.out.print("\n公钥："+Hex.toHexString(p.getQ().getEncoded(false)));

        PrivateKey privateKey = keyPair.getPrivate();
        BCECPrivateKey s=(BCECPrivateKey)privateKey;
        System.out.print("\n私钥："+Hex.toHexString(s.getD().toByteArray()));

        String data = sm2.encrypt(Hex.toHexString(p.getQ().getEncoded(false)),M);
        System.out.println("\n加密字符串："+data);

        String text=sm2.decrypt(Hex.toHexString(s.getD().toByteArray()),data);
        System.out.println("\n解密："+text);
    }
}