java sm2签名验证

以下是 Java 实现 SM2 签名和验签的示例代码：

import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
import org.bouncycastle.crypto.generators.ECKeyPairGenerator;
import org.bouncycastle.crypto.params.ECDomainParameters;
import org.bouncycastle.crypto.params.ECKeyGenerationParameters;
import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
import org.bouncycastle.crypto.params.ECPublicKeyParameters;
import org.bouncycastle.crypto.signers.SM2Signer;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.math.ec.ECPoint;

import java.security.Security;
import java.util.Base64;

public class SM2Demo {
    public static void main(String[] args) throws Exception {
        // 添加 BouncyCastle 作为 Provider
        Security.addProvider(new BouncyCastleProvider());

        // 构造椭圆曲线参数
        String p = "FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFF";
        String a = "FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFC";
        String b = "28E9FA9E9D9F5E344D5A9E4BCF6509A7F39789F515AB8F92DDBCBD414D940E93";
        String n = "FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFF7203DF6B21C6052B53BBF40939D54123";
        String gx = "32C4AE2C1F1981195F9904466A39C9948FE30BBFF2660BE171F996FFC3A4EBA4";
        String gy = "BC3736A2F4F6779C59BDCEE36B692153D0A9877CC62A474002DF32E52139F0A0";
        ECDomainParameters domainParameters = new ECDomainParameters(
                SM2Util.hexToBigInteger(p),
                SM2Util.hexToBigInteger(a),
                SM2Util.hexToBigInteger(b),
                new ECPoint(SM2Util.hexToBigInteger(gx), SM2Util.hexToBigInteger(gy)),
                SM2Util.hexToBigInteger(n));

        // 生成密钥对
        ECKeyPairGenerator keyPairGenerator = new ECKeyPairGenerator();
        ECKeyGenerationParameters keyGenerationParams = new ECKeyGenerationParameters(domainParameters, SM2Util.createFixedSecureRandom());
        keyPairGenerator.init(keyGenerationParams);
        AsymmetricCipherKeyPair keyPair = keyPairGenerator.generateKeyPair();
        ECPrivateKeyParameters privateKey = (ECPrivateKeyParameters) keyPair.getPrivate();
        ECPublicKeyParameters publicKey = (ECPublicKeyParameters) keyPair.getPublic();

        // 待签名的数据
        byte[] data = "Hello, SM2!".getBytes();

        // 签名
        SM2Signer signer = new SM2Signer();
        signer.init(true, privateKey);
        signer.update(data, 0, data.length);
        byte[] signature = signer.generateSignature();

        // 打印签名结果
        System.out.println("签名结果：" + Base64.getEncoder().encodeToString(signature));

        // 验签
        signer.init(false, publicKey);
        signer.update(data, 0, data.length);
        boolean result = signer.verifySignature(signature);

        // 打印验签结果
        System.out.println("验签结果：" + result);
    }
}

代码中使用了 Bouncy Castle 提供的 SM2 签名和验签实现。在签名阶段，我们需要使用私钥对待签名数据进行签名，生成签名值；在验签阶段，我们需要使用公钥对签名值和待签名数据进行验签，判断验签结果是否正确。