CheckSignature返回false

Question

我有一个问题，即简单签名上的CheckSignature总是失败。 我正在使用SignXml签名一些外部数据（在我的情况下是AS4有效负载的一部分），这些数据将作为MIME附件存储。

这是代码（修改后的MS示例）：

static string flXML = @"D:\Test\Example.xml";
static string flSignedXML = @"D:\Test\SignedExample.xml";
private void button1_Click(object sender, EventArgs e)
{
    try
    {
        // Generate a signing key.
        RSACryptoServiceProvider Key = new RSACryptoServiceProvider();
        CreateSomeXml(flXML);
        SignXmlFile(flXML, flSignedXML, Key);
        bool result = VerifyXmlFile(flSignedXML, Key);

        if (result)
        {
            Console.WriteLine("The XML signature is valid.");
        }
        else
        {
            Console.WriteLine("The XML signature is not valid.");
        }
    }
    catch (CryptographicException ee)
    {
        Console.WriteLine(ee.Message);
    }
}

public static void CreateSomeXml(string FileName)
{
    File.WriteAllText(FileName, "<?xml version=\"1.0\" encoding=\"utf-8\"?><MyElement xmlns=\"samples\"></MyElement>");
}        
private static readonly FieldInfo RefTargetTypeField = typeof(Reference).GetField("m_refTargetType", BindingFlags.Instance | BindingFlags.NonPublic);
private static readonly FieldInfo RefTargetField = typeof(Reference).GetField("m_refTarget", BindingFlags.Instance | BindingFlags.NonPublic);
        public static void SignXmlFile(string FileName, string SignedFileName, RSA Key)
{
    XmlDocument doc = new XmlDocument();
    doc.Load(new XmlTextReader(FileName));
    SignedXml signedXml = new SignedXml(doc);
    signedXml.SigningKey = Key;

        byte[] Content = System.Text.Encoding.UTF8.GetBytes("1234567890asdfghjkl");
        Stream stream = new MemoryStream(Content);
        var attachmentReference = new Reference(uri: "cid:xml-sample") { DigestMethod = "http://www.w3.org/2001/04/xmlenc#sha256" };

        const int streamReferenceTargetType = 0;
        RefTargetTypeField.SetValue(attachmentReference, streamReferenceTargetType);
        RefTargetField.SetValue(attachmentReference, stream);

        signedXml.AddReference(attachmentReference);

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

    XmlElement xmlDigitalSignature = signedXml.GetXml();
    doc.DocumentElement.AppendChild(doc.ImportNode(xmlDigitalSignature, true));
    if (doc.FirstChild is XmlDeclaration)
    {
        doc.RemoveChild(doc.FirstChild);
    }
    XmlTextWriter xmltw = new XmlTextWriter(SignedFileName, new UTF8Encoding(false));
    doc.WriteTo(xmltw);
    xmltw.Close();
}
public static Boolean VerifyXmlFile(String Name, RSA Key)
{
    XmlDocument xmlDocument = new XmlDocument();
    xmlDocument.Load(Name);
    SignedXml signedXml = new SignedXml(xmlDocument);
    XmlNodeList nodeList = xmlDocument.GetElementsByTagName("Signature");
    signedXml.LoadXml((XmlElement)nodeList[0]);
    {
        byte[] Content = System.Text.Encoding.UTF8.GetBytes("1234567890asdfghjkl");
        Stream stream = new MemoryStream(Content);
        var attachmentReference = new Reference(uri: "cid:xml-sample") { DigestMethod = "http://www.w3.org/2001/04/xmlenc#sha256" };

        const int streamReferenceTargetType = 0;
        RefTargetTypeField.SetValue(attachmentReference, streamReferenceTargetType);
        RefTargetField.SetValue(attachmentReference, stream);

        signedXml.AddReference(attachmentReference);
    }

    // Check the signature and return the result.
    signedXml.SigningKey = Key;
    return signedXml.CheckSignature();
}

有人知道我做错了吗？ 附带一提，我知道我可以为其他参考指定转换。 问题是，如何获取SignedXml处理的引用结果，以便我也可以存储该结果？ 例如，如果我指定压缩以进行参考转换，那么现在如何获得该压缩的结果？

Answer 1

当签名验证失败时，启用记录器将有助于您提供更多有关错误原因的信息。

您可以通过将其添加到您的app.config文件中来启用它：

<system.diagnostics>
    <sources>
      <source name="System.Security.Cryptography.Xml.SignedXml" switchName="XmlDsigLogSwitch">
        <listeners>
          <add name="xmlDsigLogFile" />
        </listeners>
      </source>
    </sources>

    <switches>
      <add name="XmlDsigLogSwitch" value="Verbose" />
      <!-- possible values: Off (0) Error (1) Warning (2) Info (3) Verbose (4) -->
    </switches>

    <sharedListeners>
      <add name="xmlDsigLogFile" type="System.Diagnostics.TextWriterTraceListener" initializeData="XmlDsigLog.txt" />
    </sharedListeners>

    <trace autoflush="true">
      <listeners>
        <add name="xmlDsigLogFile" />
      </listeners>
    </trace>
  </system.diagnostics>

当附件是XML附件时，应使用XmlDsigExcC14NTransform转换。 如果附件不是XML附件，则不应使用它。