Java 使用 BouncyCastle 库实现 SM2 算法和 PKCS#7 签名/验签

以下是一个示例代码，演示了如何使用 BouncyCastle 库在 Java 中实现 SM2 算法和 PKCS#7 签名/验签功能：

import org.bouncycastle.asn1.ASN1Encodable;
import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.asn1.ASN1Primitive;
import org.bouncycastle.asn1.DERSet;
import org.bouncycastle.asn1.cms.ContentInfo;
import org.bouncycastle.asn1.cms.SignerIdentifier;
import org.bouncycastle.asn1.cms.SignerInfo;
import org.bouncycastle.asn1.pkcs.PKCSObjectIdentifiers;
import org.bouncycastle.asn1.pkcs.PrivateKeyInfo;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.cert.X509CertificateHolder;
import org.bouncycastle.cms.CMSAlgorithm;
import org.bouncycastle.cms.CMSException;
import org.bouncycastle.cms.CMSSignedData;
import org.bouncycastle.cms.CMSSignedDataGenerator;
import org.bouncycastle.cms.CMSSignedDataParser;
import org.bouncycastle.cms.CMSTypedData;
import org.bouncycastle.cms.SignerInformation;
import org.bouncycastle.cms.SignerInformationStore;
import org.bouncycastle.cms.jcajce.JcaCertStore;
import org.bouncycastle.cms.jcajce.JcaSimpleSignerInfoGeneratorBuilder;
import org.bouncycastle.cms.jcajce.JcaX509CertificateHolder;
import org.bouncycastle.cms.jcajce.JcaX509ContentVerifierProviderBuilder;
import org.bouncycastle.jcajce.provider.asymmetric.sm.SM2PrivateKey;
import org.bouncycastle.jcajce.provider.asymmetric.sm.SM2PublicKey;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.operator.ContentSigner;
import org.bouncycastle.operator.OperatorCreationException;
import org.bouncycastle.operator.jcajce.JcaContentSignerBuilder;
import org.bouncycastle.operator.jcajce.JcaDigestCalculatorProviderBuilder;
import org.bouncycastle.util.Store;
import org.bouncycastle.util.encoders.Base64;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Security;
import java.security.cert.CertificateEncodingException;
import java.security.cert.CertificateException;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

public class SM2PKCS7Example {

    public static void main(String[] args) throws Exception {
        Security.addProvider(new BouncyCastleProvider());

        // 生成SM2密钥对
        KeyPair keyPair = generateSM2KeyPair();

        // 加载PKCS#8格式的私钥
        PrivateKey privateKey = loadPrivateKey(keyPair.getPrivate().getEncoded());

        // 加载X.509格式的证书
        X509Certificate certificate = loadCertificate(loadCertificateBytes());

        // 待签名数据
        byte[] data = 'Hello, World!'.getBytes();

        // 签名数据
        byte[] signature = signData(data, privateKey, certificate);

        // 验证签名
        boolean verified = verifySignature(data, signature);

        System.out.println('Signature Verified: ' + verified);
    }

    private static KeyPair generateSM2KeyPair() throws NoSuchAlgorithmException {
        KeyPairGenerator generator = KeyPairGenerator.getInstance('SM2', 'BC');
        return generator.generateKeyPair();
    }

    private static PrivateKey loadPrivateKey(byte[] privateKeyBytes) throws NoSuchAlgorithmException, InvalidKeySpecException {
        KeyFactory keyFactory = KeyFactory.getInstance('SM2', 'BC');
        PKCS8EncodedKeySpec privateKeySpec = new PKCS8EncodedKeySpec(privateKeyBytes);
        return keyFactory.generatePrivate(privateKeySpec);
    }

    private static X509Certificate loadCertificate(byte[] certificateBytes) throws CertificateException {
        CertificateFactory certificateFactory = CertificateFactory.getInstance('X.509');
        return (X509Certificate) certificateFactory.generateCertificate(new ByteArrayInputStream(certificateBytes));
    }

    private static byte[] loadCertificateBytes() {
        // TODO: Load certificate bytes from a file or other source
    }

    private static byte[] signData(byte[] data, PrivateKey privateKey, X509Certificate certificate) throws OperatorCreationException, CertificateEncodingException, CMSException {
        // 构建签名者信息
        List<X509CertificateHolder> certList = new ArrayList<>();
        certList.add(new JcaX509CertificateHolder(certificate));

        Store<X509CertificateHolder> certs = new JcaCertStore(certList);

        SignerInfoGenerator signerInfoGenerator = new JcaSimpleSignerInfoGeneratorBuilder()
                .setProvider('BC')
                .build('SM3withSM2', (SM2PrivateKey) privateKey, certificate);

        // 构建签名数据生成器
        CMSSignedDataGenerator signedDataGenerator = new CMSSignedDataGenerator();

        signedDataGenerator.addSignerInfoGenerator(signerInfoGenerator);
        signedDataGenerator.addCertificates(certs);

        // 设置待签名的数据
        CMSTypedData cmsData = new CMSProcessableByteArray(data);

        // 生成签名数据
        CMSSignedData signedData = signedDataGenerator.generate(cmsData, true);

        // 将签名数据转换为字节数组
        return signedData.getEncoded();
    }

    private static boolean verifySignature(byte[] data, byte[] signature) throws CMSException, IOException, OperatorCreationException {
        CMSSignedDataParser parser = new CMSSignedDataParser(new JcaDigestCalculatorProviderBuilder().setProvider('BC').build(), signature);

        // 解析签名数据
        parser.getSignedContent().drain();

        // 获取签名者信息
        SignerInformationStore signerInfos = parser.getSignerInfos();
        Collection<SignerInformation> signers = signerInfos.getSigners();

        Iterator<SignerInformation> signerIterator = signers.iterator();
        if (signerIterator.hasNext()) {
            SignerInformation signer = signerIterator.next();

            // 验证签名
            return signer.verify(new JcaX509ContentVerifierProviderBuilder().setProvider('BC').build(signer.getSID()));
        }

        return false;
    }
}

在上面的代码中，我们使用 BouncyCastle 库生成 SM2 密钥对，加载私钥和证书，然后使用私钥和证书对数据进行签名，并验证签名的有效性。

请注意，这只是一个示例代码，你需要根据你的具体需求进行相应的调整，例如加载证书的方式。