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Код

//
// This example signs a file specified by a URI 
// using a detached signature. It then verifies  
// the signed XML.
//

#using <mscorlib.dll>
#using <System.dll>
#using <System.Xml.dll>
#using <System.Security.dll>

using namespace System;
using namespace System::Security::Cryptography;
using namespace System::Security::Cryptography::Xml;
using namespace System::Text;
using namespace System::Xml;

// Sign an XML file and save the signature in a new file. This method does not  
// save the public key within the XML file.  This file cannot be verified unless  
// the verifying code has the key with which it was signed.
void SignDetachedResource(String* URIString, String* XmlSigFileName, RSA* Key)
{
    // Create a SignedXml object.
    SignedXml* signedXml = new SignedXml();

    // Assign the key to the SignedXml object.
    signedXml->SigningKey = Key;

    // Create a reference to be signed.
    Reference* reference = new Reference();

    // Add the passed URI to the reference object.
    reference->Uri = URIString;

    // Add a transformation if the URI is an XML file.
    if (URIString->EndsWith(S"xml")) 
    {
        reference->AddTransform(new XmlDsigC14NTransform());
    }

    // 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();

    // Save the signed XML document to a file specified
    // using the passed string.
    XmlTextWriter* xmltw = new XmlTextWriter(XmlSigFileName, new UTF8Encoding(false));
    xmlDigitalSignature->WriteTo(xmltw);
    xmltw->Close();

}

// Verify the signature of an XML file against an asymetric 
// algorithm and return the result.
static Boolean VerifyDetachedSignature(String* XmlSigFileName, RSA* Key)
{    
    // Create a new XML document.
    XmlDocument* xmlDocument = new XmlDocument();

    // Load the passedXML file into the document.
    xmlDocument->Load(XmlSigFileName);

    // Create a new SignedXml object.
    SignedXml* signedXml = new SignedXml();

    // Find the "Signature" node and create a new
    // XmlNodeList object.
    XmlNodeList* nodeList = xmlDocument->GetElementsByTagName(S"Signature");

    // Load the signature node.
    signedXml->LoadXml(dynamic_cast<XmlElement*>(nodeList->ItemOf[0]));

    // Check the signature against the passed asymetric key
    // and return the result.
    return signedXml->CheckSignature(Key);
}

int main()
{
    // The URI to sign.
    String* resourceToSign = S"http://www.microsoft.com";

    // The name of the file to which to save the XML signature.
    String* XmlFileName = S"xmldsig.xml";

    try
    {

        // Generate a signing key.
        RSACryptoServiceProvider* Key = new RSACryptoServiceProvider();

        Console::WriteLine(S"Signing: {0}", resourceToSign);

        // Sign the detached resourceand save the signature in an XML file.
        SignDetachedResource(resourceToSign, XmlFileName, Key);

        Console::WriteLine(S"XML Signature was succesfully computed and saved to {0}.", XmlFileName);

        // Verify the signature of the signed XML.
        Console::WriteLine(S"Verifying signature...");

        //Verify the XML signature in the XML file against the key.
        bool result = VerifyDetachedSignature(XmlFileName, Key);

        // Display the results of the signature verification to 
        // the console.
        if(result)
        {
            Console::WriteLine(S"The XML signature is valid.");
        }
        else
        {
            Console::WriteLine(S"The XML signature is not valid.");
        }
    }
    catch(CryptographicException* e)
    {
        Console::WriteLine(e->Message);

    }