BC库实现SM2证书PKCS7签名

要在BC库中实现SM2证书PKCS7签名，您可以按照以下步骤进行操作：

导入所需的库文件：

import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.cert.jcajce.JcaCertStore;
import org.bouncycastle.cert.jcajce.JcaX509CertificateHolder;
import org.bouncycastle.cms.*;
import org.bouncycastle.cms.jcajce.JcaSimpleSignerInfoGeneratorBuilder;
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.util.Store;

添加Bouncy Castle提供的安全提供程序（Bouncy Castle Provider）：

Security.addProvider(new BouncyCastleProvider());

创建一个空的CMS SignedData对象：

CMSSignedDataGenerator cmsSignedDataGenerator = new CMSSignedDataGenerator();

创建签名者信息生成器：

JcaSimpleSignerInfoGeneratorBuilder signerInfoGeneratorBuilder = new JcaSimpleSignerInfoGeneratorBuilder().setProvider("BC");
ContentSigner contentSigner = new JcaContentSignerBuilder("SM3withSM2").setProvider("BC").build(privateKey);
SignerInfoGenerator signerInfoGenerator = signerInfoGeneratorBuilder.build(contentSigner, certificate);

将证书和私钥添加到证书存储中：

List<X509Certificate> certList = new ArrayList<>();
certList.add(certificate);
JcaCertStore certStore = new JcaCertStore(certList);
cmsSignedDataGenerator.addCertificates(certStore);

使用签名者信息生成器生成签名者信息：

SignerInfoGenerator[] signerInfoGenerators = new SignerInfoGenerator[]{signerInfoGenerator};
cmsSignedDataGenerator.addSigners(signerInfoGenerators);

获取要签名的数据：

byte[] dataToSign = "Hello, World!".getBytes();

通过CMS ProcessableByteArray对象包装要签名的数据：

CMSProcessableByteArray cmsProcessableByteArray = new CMSProcessableByteArray(dataToSign);

生成CMS SignedData对象：

CMSSignedData cmsSignedData = cmsSignedDataGenerator.generate(cmsProcessableByteArray, true);

获取PKCS7签名数据：

byte[] pkcs7Signature = cmsSignedData.getEncoded();

这样，您就可以使用BC库实现SM2证书PKCS7签名了。请注意，上述代码中的privateKey和certificate分别是您要使用的私钥和证书。您需要将其替换为实际的私钥和证书