使用BouncyCastle将已签名/已认证的属性添加到CMS签名

Question

我想使用Bouncycastle生成一个简单的CMS签名。此代码有效！

  Security.addProvider(new BouncyCastleProvider());
  String password = "123456";
  KeyStore ks = KeyStore.getInstance("PKCS12");
  ks.load(new FileInputStream("c:/cert_123456.p12"), password.toCharArray());
  String alias = (String)ks.aliases().nextElement();
  PrivateKey key = (PrivateKey)ks.getKey(alias, password.toCharArray());
  Certificate[] chain = ks.getCertificateChain(alias);

  CMSSignedDataGenerator generator = new CMSSignedDataGenerator();

  generator.addSigner(key, (X509Certificate)chain[0], CMSSignedDataGenerator.DIGEST_SHA1);
  ArrayList list = new ArrayList();
  for (int i = 0; i < chain.length; i++) {
       list.add(chain[i]);
  }
  CertStore chainStore = CertStore.getInstance("Collection", new CollectionCertStoreParameters(list), "BC");
  generator.addCertificatesAndCRLs(chainStore);
  CMSProcessable content = new CMSProcessableByteArray("test".getBytes());
  CMSSignedData signedData = generator.generate(content, false, "BC");

  byte[] pk = signedData.getEncoded();

但是，如何添加签名属性？
我想删除默认的签名属性并添加signature-policy-identifier。

文章非常受欢迎。

Answer 1

首先，您似乎正在使用最新版本的Bouncy
Castle中不推荐使用的构造。要添加经过身份验证/签名的属性，您必须将它们打包到AttributeTable中，将签名的属性添加到签名者，如下所示：

ASN1EncodableVector signedAttributes = new ASN1EncodableVector();
signedAttributes.add(new Attribute(CMSAttributes.contentType, new DERSet(new ASN1ObjectIdentifier("1.2.840.113549.1.7.1"))));
signedAttributes.add(new Attribute(CMSAttributes.messageDigest, new DERSet(new DEROctetString(digestBytes))));
signedAttributes.add(new Attribute(CMSAttributes.signingTime, new DERSet(new DERUTCTime(signingDate))));

AttributeTable signedAttributesTable = new AttributeTable(signedAttributes);

然后在addSigner方法之一中使用它。正如我在开始时已经提到的那样，不建议使用此方法，建议您使用Generators和Generator
Builders。这是一个简短的示例：

    /* Construct signed attributes */
    ASN1EncodableVector signedAttributes = new ASN1EncodableVector();
    signedAttributes.add(new Attribute(CMSAttributes.contentType, new DERSet(new ASN1ObjectIdentifier("1.2.840.113549.1.7.1"))));
    signedAttributes.add(new Attribute(CMSAttributes.messageDigest, new DERSet(new DEROctetString(digestBytes))));
    signedAttributes.add(new Attribute(CMSAttributes.signingTime, new DERSet(new DERUTCTime(signingDate))));

    AttributeTable signedAttributesTable = new AttributeTable(signedAttributes);
    signedAttributesTable.toASN1EncodableVector();
    DefaultSignedAttributeTableGenerator signedAttributeGenerator = new DefaultSignedAttributeTableGenerator(signedAttributesTable);

    /* Build the SignerInfo generator builder, that will build the generator... that will generate the SignerInformation... */
    SignerInfoGeneratorBuilder signerInfoBuilder = new SignerInfoGeneratorBuilder(new JcaDigestCalculatorProviderBuilder().setProvider("BC").build());
    signerInfoBuilder.setSignedAttributeGenerator(signedAttributeGenerator);
    CMSSignedDataGenerator generator = new CMSSignedDataGenerator();
    JcaContentSignerBuilder contentSigner = new JcaContentSignerBuilder("SHA1withRSA");
    contentSigner.setProvider("BC");

    generator.addSignerInfoGenerator(signerInfoBuilder.build(contentSigner.build(this.signingKey), new X509CertificateHolder(this.signingCert.getEncoded())));

    ArrayList<X509CertificateHolder> signingChainHolder = new ArrayList<X509CertificateHolder>();
    Iterator i = this.signingChain.iterator();
    while (i.hasNext()) {
        X509CertificateObject cert = (X509CertificateObject)i.next();
        signingChainHolder.add(new X509CertificateHolder(cert.getEncoded()));
    }

    generator.addCertificates(new JcaCertStore(signingChainHolder));
    generator.generate(new CMSAbsentContent(), "BC").getEncoded();

它非常笨重，可能还无法正常工作（我正在编写过程中，在研究某些东西时偶然发现了您的问题），尤其是signingDate部分，它可能必须是new DERSet(new Time(new Date))（update：它可以使用DERUTCTime）。

有点离题：我仍然无法理解Signed和Authenticated属性之间的区别，Bouncy
Castle拥有DefaultAuthenticatedAttributeTableGenerator和DefaultSignedAttributeTableGenerator类，它们与Signers完美配合。两者之间在signingTime方面似乎有一些细微的差异，如果不存在，SignedAttributes默认会添加signingTime。RFC提到了两种属性类型，但是我找不到任何确定的东西。