SM2加解密

需要使用SM2进行加解密，百度查询的都是自己生成密钥对，然后进行加解密。现在密钥对已给，需要构造加解密公私钥对象进行加解密操作。最后找到hutool工具包直接可以根据公私钥进行构造一SM2对象。查看源码研究了下翻译一下使用bouncycastle包进行实现大致如下这样

添加依赖包

    org.bouncycastle
    bcprov-jdk15on
    1.65

根据现有公私钥信息进行加密解密

import org.bouncycastle.asn1.gm.GMNamedCurves;
import org.bouncycastle.asn1.x9.X9ECParameters;
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.Digest;
import org.bouncycastle.crypto.digests.SM3Digest;
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.jcajce.provider.asymmetric.ec.BCECPrivateKey;
import org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPublicKey;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.math.ec.ECCurve;
import org.bouncycastle.math.ec.ECPoint;
import org.bouncycastle.util.BigIntegers;
import org.bouncycastle.util.encoders.Hex;

public class SM2Test {
	static String SM2_CURVE_NAME = "sm2p256v1";
	
    
	public static void main(String[] args) throws Exception {
		//私钥
	    String prvKey = "23be18173850ac04c5255984759e15bf60a8eb0f54880b01a9bc24e20e82df48";
	    //公钥坐标
	    String x = "741192ca3ee1a2ba9a50ccab30dd069b29437e2f38fcba709bf84f8a3e732584";
	    String y = "a47f526415387d5eeb48257fa6e4a5603c7b2ba729ede7c61dfe109d89bd02b1";
	    
        String info = "中国";
        byte[] data = info.getBytes();
        
        SM2Test sm2 = new SM2Test();
        
        //KeyPair keyPair = sm2.genKeyPair();
       
        ECDomainParameters domain = sm2.getDomain();
        SM2Engine engine = sm2.getSM2Engine();
		//公钥加密
		CipherParameters pubKeyParameters = sm2.getPubKey(x, y, domain);
		engine.init(true, pubKeyParameters);
		byte[] encData = engine.processBlock(data, 0, data.length);
		System.out.println("加密后内容:"+Hex.toHexString(encData));
		//私钥解密
		CipherParameters PrivateKey = sm2.getPrvKey(prvKey,domain);
		engine.init(false, PrivateKey);
		byte[] decData = engine.processBlock(encData, 0, encData.length);
		System.out.println("解密后内容:"+new String(decData));
		
	}
	
	/**
	 * 构造私钥对象
	 * @param prvKey
	 * @return
	 */
	public CipherParameters getPrvKey(String prvKey,ECDomainParameters domain) {
		BigInteger prvKeyData = BigIntegers.fromUnsignedByteArray(Hex.decode(prvKey));
		ECPrivateKeyParameters PrivateKey = new ECPrivateKeyParameters(prvKeyData, domain);
		return PrivateKey;
	}
	
	/**
	 * 构造公钥对象
	 * @param x
	 * @param y
	 * @param domain
	 * @return
	 */
	public CipherParameters getPubKey(String x,String y,ECDomainParameters domain) {
		ECCurve curve = domain.getCurve();
		ECPoint point = curve.createPoint(BigIntegers.fromUnsignedByteArray(Hex.decode(x)), BigIntegers.fromUnsignedByteArray(Hex.decode(y)));
		ECPublicKeyParameters PublicKey = new ECPublicKeyParameters(point, domain);
		CipherParameters pubKeyParameters = new ParametersWithRandom(PublicKey);
		return pubKeyParameters;
	}
	
	public SM2Engine getSM2Engine() {
		Digest digest = new SM3Digest();
		SM2Engine engine =  new SM2Engine(digest,SM2Engine.Mode.C1C3C2);
		return engine;
	}
	
	public ECDomainParameters getDomain() {
		X9ECParameters x9ECParameters= GMNamedCurves.getByName(SM2_CURVE_NAME);
		ECDomainParameters domain  = new ECDomainParameters(
				x9ECParameters.getCurve(),
				x9ECParameters.getG(),
				x9ECParameters.getN(),
				x9ECParameters.getH()
		);
		return domain;
	}
	
	/**
	 * 生成密钥对
	 * @return
	 * @throws Exception
	 */
	public KeyPair genKeyPair() throws Exception {
		final ECGenParameterSpec sm2Spec = new ECGenParameterSpec(SM2_CURVE_NAME);
        // 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());
        SecureRandom random = new SecureRandom();
        // 使用SM2的算法区域初始化密钥生成器
        kpg.initialize(sm2Spec, random);
        // 获取密钥对
        KeyPair keyPair = kpg.generateKeyPair();
        
        BCECPublicKey pubk = (BCECPublicKey) keyPair.getPublic();
        BCECPrivateKey privK = (BCECPrivateKey) keyPair.getPrivate();
        byte[] privData = BigIntegers.asUnsignedByteArray(32,privK.getD());
        byte[] pubx = BigIntegers.asUnsignedByteArray(32, pubk.getQ().getRawXCoord().toBigInteger());
        byte[] puby = BigIntegers.asUnsignedByteArray(32, pubk.getQ().getRawYCoord().toBigInteger());
        System.out.println("Private Key:"+Hex.toHexString(privData));
        System.out.println("PUB X:"+Hex.toHexString(pubx));
        System.out.println("PUB Y:"+Hex.toHexString(puby));
        return keyPair;
	}