Bouncy Castle SM2加解密

配置过程

• 下载相关包。我参考了连接：https://blog.csdn.net/weixin_42221688/article/details/90475014
  
• 修改配置文件$JAVA_HOME$\jre\lib\security\java.security，在末尾添加security.provider.11=org.bouncycastle.jce.provider.BouncyCastleProvider；
  
• 测试：
  

代码运行

sm2_demo类：//调用SM2加解密功能

package BC;

import org.bouncycastle.jce.provider.BouncyCastleProvider;

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

public class sm2_demo {
    private static String M = "20201217王菁";

    public static void main(String[] args) throws NoSuchAlgorithmException, InvalidAlgorithmParameterException {
        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();
        PrivateKey privateKey = keyPair.getPrivate();

        String data = sm2.encrypt(publicKey, M);
        System.out.println("明文:"+M);
        System.out.println("密文:"+data);

        String text = sm2.decrypt(privateKey, data);
        System.out.println("解密结果："+text);
    }
}

SM2Util类：

package BC;

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.spec.ECParameterSpec;
import org.bouncycastle.util.encoders.Hex;

import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;

public class SM2Util {
    /**
     * SM2加密算法
     *
     * @param publicKey 公钥
     * @param data      明文数据
     * @return
     */
    public String encrypt(PublicKey publicKey, String data) {
        ECPublicKeyParameters ecPublicKeyParameters = null;
        if (publicKey instanceof BCECPublicKey) {
            BCECPublicKey bcecPublicKey = (BCECPublicKey) publicKey;
            ECParameterSpec ecParameterSpec = bcecPublicKey.getParameters();
            ECDomainParameters ecDomainParameters = new ECDomainParameters(ecParameterSpec.getCurve(),
                    ecParameterSpec.getG(), ecParameterSpec.getN());
            ecPublicKeyParameters = new ECPublicKeyParameters(bcecPublicKey.getQ(), ecDomainParameters);
        }
        SM2Engine sm2Engine = new SM2Engine();
        sm2Engine.init(true, new ParametersWithRandom(ecPublicKeyParameters, new SecureRandom()));
        byte[] arrayOfBytes = null;
        try {
            byte[] in = data.getBytes("utf-8");
            arrayOfBytes = sm2Engine.processBlock(in, 0, in.length);
        } catch (Exception e) {
            System.out.println("SM2加密时出现异常:");
        }
        return Hex.toHexString(arrayOfBytes);
    }

    /**
     * SM2解密算法
     *
     * @param privateKey 私钥
     * @param cipherData 密文数据
     * @return
     */
    public String decrypt(PrivateKey privateKey, String cipherData) {
        byte[] cipherDataByte = Hex.decode(cipherData);
        BCECPrivateKey bcecPrivateKey = (BCECPrivateKey) privateKey;
        ECParameterSpec ecParameterSpec = bcecPrivateKey.getParameters();
        ECDomainParameters ecDomainParameters = new ECDomainParameters(ecParameterSpec.getCurve(),
                ecParameterSpec.getG(), ecParameterSpec.getN());
        ECPrivateKeyParameters ecPrivateKeyParameters = new ECPrivateKeyParameters(bcecPrivateKey.getD(),
                ecDomainParameters);
        SM2Engine sm2Engine = new SM2Engine();
        sm2Engine.init(false, ecPrivateKeyParameters);
        String result = null;
        try {
            byte[] arrayOfBytes = sm2Engine.processBlock(cipherDataByte, 0, cipherDataByte.length);
            return new String(arrayOfBytes, "utf-8");
        } catch (Exception e) {
            System.out.println("SM2解密时出现异常");
        }
        return result;
    }
}

运行结果