如何使用 X509 证书签署 xml，将摘要值和签名添加到 xml 模板

Question

我是 C# 的新手，尤其是使用 X509 签名的新手。我有一个 xml 模板，我必须在其中添加使用的证书（完成）并签署时间戳 (TS-1)、二进制安全令牌和正文 (id-1)。此外，我需要用这 3 个元素的摘要值编写（例如替换占位符）并添加签名值。

但是，我不是很理解这个概念，例如这该怎么做。我阅读了几个网站，例如signing a xml document with x509 certificate 但我无法使代码适应我的问题。

这是我尝试过的：

public static string SignXml(string template)
{

    XmlDocument document = new XmlDocument();
    document.LoadXml(template);

        // define elements that will be signed
        XmlNode securityToken = null;
        XmlNode validityPeriod = null;
        XmlNode body = null;
        XmlNode signedInfo = null;
        XmlNode signatureValue = null;
        XmlNodeList digestTags = null;



        XmlNamespaceManager namespaces = new XmlNamespaceManager(document.NameTable);
        namespaces.AddNamespace("ns", "http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd");
        namespaces.AddNamespace("nu", "http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd");
        namespaces.AddNamespace("bo", "http://schemas.xmlsoap.org/soap/envelope/");
        namespaces.AddNamespace("si", "http://www.w3.org/2000/09/xmldsig#");
        namespaces.AddNamespace("sinfo", "soapenv xd xe");

        document.LoadXml(template);
        //XmlNode idNode = document.SelectSingleNode("/My_RootNode/ns:id", namespaces);

        securityToken = document.SelectSingleNode("descendant::ns:BinarySecurityToken", namespaces);
        validityPeriod = document.SelectSingleNode("descendant::nu:Timestamp", namespaces);
        body = document.SelectSingleNode("descendant::bo:Body", namespaces);
        signedInfo = document.SelectSingleNode("descendant::si:SignedInfo", namespaces);
        signatureValue = document.SelectSingleNode("descendant::si::sinfo:SignatureValue", namespaces);
        digestTags = document.SelectNodes("descendant::si:DigestValue", namespaces);

        // add the digests (to know where to write the digests)
        String nodeName = null;
        for (int counter = 0; counter < digestTags.Count; counter++)
        {
            nodeName = digestTags[counter].FirstChild.InnerText;
            if (WebserviceConstants.PLACEHOLDER_AUTHNREQUEST_DIGEST.Equals(nodeName))
            {

                generateDigest(body, digestTags[counter]);
            }
            else if (WebserviceConstants.PLACEHOLDER_CERTIFICATE_DIGEST.Equals(nodeName))
            {

                generateDigest(securityToken, digestTags[counter]);
            }
            else if (WebserviceConstants.PLACEHOLDER_TIMESTAMP_TAG_DIGEST.Equals(nodeName))
            {

                generateDigest(validityPeriod, digestTags[counter]);
            }
        }



        SignedXml signedXml = new SignedXml(document);



    X509Certificate2 cert = new X509Certificate2();
    cert = getbase();

    signedXml.SigningKey = cert.PrivateKey;

    // Create a reference to be signed.
    Reference reference = new Reference();
    reference.Uri = "#TS-1";

    // Add an enveloped transformation to the reference.            
    XmlDsigEnvelopedSignatureTransform env =
       new XmlDsigEnvelopedSignatureTransform(true);
    reference.AddTransform(env);

    //canonicalize
    XmlDsigC14NTransform c14t = new XmlDsigC14NTransform();
    reference.AddTransform(c14t);

    KeyInfo keyInfo = new KeyInfo();
    KeyInfoX509Data keyInfoData = new KeyInfoX509Data(cert);
    KeyInfoName kin = new KeyInfoName();
    kin.Value = "Public key of certificate";
    RSACryptoServiceProvider rsaprovider = (RSACryptoServiceProvider)cert.PublicKey.Key;
    RSAKeyValue rkv = new RSAKeyValue(rsaprovider);
    keyInfo.AddClause(kin);
    keyInfo.AddClause(rkv);
    keyInfo.AddClause(keyInfoData);
    signedXml.KeyInfo = keyInfo;

    // Add the reference to the SignedXml object.
    signedXml.AddReference(reference);

    // Compute the signature.
    signedXml.ComputeSignature();

    // Get the XML representation of the signature and save 
    // it to an XmlElement object.
    XmlElement xmlDigitalSignature = signedXml.GetXml();

    document.DocumentElement.AppendChild(
    document.ImportNode(xmlDigitalSignature, true));
    document.DocumentElement.AppendChild(document.ImportNode(xmlDigitalSignature, true));

        return document.OuterXml;
    }
}

我在质疑自己：

如何获取摘要值以及如何将其写入对应的xml节点
如何计算签名值，因为它 "contains" 所有 3 个引用的签名信息？？？

如您所见，我缺少一些一般背景和理解。如果你能帮助我，那就太好了！

谢谢

Answer 1

您不必手动创建签名的节点，在计算签名后调用 GetXml 方法（您已经在这样做：signedXml.GetXml()），这将 return 像这样：

<Signature xmlns="http://www.w3.org/2000/09/xmldsig#">
  <SignedInfo>
    <CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315" />
    <SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1" />
    <Reference URI="">
        <Transforms>
            <Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />
            <Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315" />
        </Transforms>
        <DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1" />
        <DigestValue>zRSPtja5EtX7hVbyJ11EjoYTRDk=</DigestValue>
    </Reference>
  </SignedInfo>
  <SignatureValue>Ua1/WP28WzfXaxUj....</SignatureValue>
  <KeyInfo>        
    <X509Data>
        <X509Certificate>MIIF3jCCBUegAwIBAgIEPQa1....</X509Certificate>
    </X509Data>
  </KeyInfo>
</Signature>

那么您只需替换 xml 模板上的整个签名节点。

--请记住，SignedXml 现在将为您提供该结构，我将回答您的问题

您的第一个问题是关于您参考文献的摘要值吗？如果是这样，当您调用 ComputeSignature 方法时，它将对其进行计算并将其添加到相应的 xml 节点。

签名值是在您计算签名时计算的，您不必自己计算。

当您调用 ComputeSignature 方法时，它所做的是获取 SignedInfo 节点并消化它。您的引用在此节点内，因此您将获得包含所有引用信息的签名值

这就是 ComputeSignature 方法如何获取 signedinfo 节点的摘要值，使用该值计算签名值：

XmlElement e = this.SignedInfo.GetXml(); //get the signedinfo nodes
document.AppendChild(document.ImportNode(e, true));
Transform canonicalizationMethodObject=this.SignedInfo.CanonicalizationMethodObject;
canonicalizationMethodObject.LoadInput(document);
canonicalizationMethodObject.GetDigestedOutput(hash); //digest the signedinfo node

如何使用 X509 证书签署 xml，将摘要值和签名添加到 xml 模板

How to sign xml with X509 cert, add digest value and signature to xml template

c#

xml

x509

sign

digest