package com.sunyard.chsm.sdf;


import com.sunyard.chsm.sdf.model.EccKey;
import com.sunyard.chsm.sdf.model.EccPriKey;
import com.sunyard.chsm.sdf.model.EccPubKey;
import lombok.SneakyThrows;
import org.bouncycastle.asn1.gm.GMNamedCurves;
import org.bouncycastle.asn1.gm.GMObjectIdentifiers;
import org.bouncycastle.asn1.x9.X9ECParameters;
import org.bouncycastle.crypto.digests.SM3Digest;
import org.bouncycastle.crypto.macs.HMac;
import org.bouncycastle.crypto.params.KeyParameter;
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.util.BigIntegers;
import org.springframework.stereotype.Service;

import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.SecureRandom;

/**
 * @author liulu
 * @since 2024/10/23
 */
@Service
public class BCSdfApiService implements SdfApiService {


    @Override
    public byte[] generateRandom(int len) {
        byte[] res = new byte[len];
        new SecureRandom().nextBytes(res);
        return res;
    }

    @SneakyThrows
    @Override
    public EccKey genKeyPairEcc() {

        // 获取SM2参数
        X9ECParameters sm2Params = GMNamedCurves.getByOID(GMObjectIdentifiers.sm2p256v1);
        ECParameterSpec sm2Spec = new ECParameterSpec(sm2Params.getCurve(), sm2Params.getG(), sm2Params.getN(), sm2Params.getH());

        // 创建密钥对生成器
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("EC", BouncyCastleProvider.PROVIDER_NAME);
        keyPairGenerator.initialize(sm2Spec);

        // 生成密钥对
        KeyPair keyPair = keyPairGenerator.generateKeyPair();
        BCECPublicKey pubKey = (BCECPublicKey) keyPair.getPublic();
        BCECPrivateKey priKey = (BCECPrivateKey) keyPair.getPrivate();
        byte[] x = pubKey.getQ().getXCoord().getEncoded();
        byte[] y = pubKey.getQ().getYCoord().getEncoded();
        byte[] d = BigIntegers.asUnsignedByteArray(64, priKey.getD());

        return new EccKey(new EccPubKey(256, x, y), new EccPriKey(256, d));
    }

    @Override
    public EccKey genEccKeyPairAndEncByKek() {
        return null;
    }

    @Override
    public byte[] calculateMAC(byte[] symKey, byte[] pucIv, byte[] pucData) {
        return new byte[0];
    }

    @Override
    public byte[] hmac(byte[] key, byte[] srcData) {
        KeyParameter keyParameter = new KeyParameter(key);
        SM3Digest digest = new SM3Digest();
        HMac mac = new HMac(digest);
        mac.init(keyParameter);
        mac.update(srcData, 0, srcData.length);
        byte[] result = new byte[mac.getMacSize()];
        mac.doFinal(result, 0);
        return result;
    }

    @Override
    public byte[] hash(byte[] pucData) {
        SM3Digest digest = new SM3Digest();
        digest.update(pucData, 0, pucData.length);
        byte[] hash = new byte[digest.getDigestSize()];
        digest.doFinal(hash, 0);
        return hash;
    }

}