RemoteCertificateValidationCallback Delegát

Definice

Obor názvů:

System.Net.Security

Sestavení:

System.Net.Security.dll

Ověří vzdálený certifikát SSL (Secure Sockets Layer) používaný k ověřování.

public delegate bool RemoteCertificateValidationCallback(System::Object ^ sender, X509Certificate ^ certificate, X509Chain ^ chain, SslPolicyErrors sslPolicyErrors);

public delegate bool RemoteCertificateValidationCallback(object sender, X509Certificate? certificate, X509Chain? chain, SslPolicyErrors sslPolicyErrors);

type RemoteCertificateValidationCallback = delegate of obj * X509Certificate * X509Chain * SslPolicyErrors -> bool

Public Delegate Function RemoteCertificateValidationCallback(sender As Object, certificate As X509Certificate, chain As X509Chain, sslPolicyErrors As SslPolicyErrors) As Boolean 

Parametry

sender

Object

Objekt, který obsahuje informace o stavu pro toto ověření.

certificate

X509Certificate

Certifikát použitý k ověření vzdálené strany.

chain

X509Chain

Řetěz certifikačních autorit přidružených ke vzdálenému certifikátu.

sslPolicyErrors

SslPolicyErrors

Jedna nebo více chyb souvisejících se vzdáleným certifikátem

Návratová hodnota

Boolean

Hodnota Boolean , která určuje, zda je zadaný certifikát přijat k ověřování.

Příklady

Následující příklad kódu implementuje metodu, která je vyvolána instancí RemoteCertificateValidationCallback třídy . Pokud dojde k chybám ověřování, tato metoda je zobrazí a vrátí false, což zabrání komunikaci s neověřeným serverem.

    // Load a table of errors that might cause 
    // the certificate authentication to fail.
    static void InitializeCertificateErrors()
    {
        certificateErrors->Add(0x800B0101,
            "The certification has expired.");
        certificateErrors->Add(0x800B0104,
            "A path length constraint "
            "in the certification chain has been violated.");
        certificateErrors->Add(0x800B0105,
            "A certificate contains an unknown extension "
            "that is marked critical.");
        certificateErrors->Add(0x800B0107,
            "A parent of a given certificate in fact "
            "did not issue that child certificate.");
        certificateErrors->Add(0x800B0108,
            "A certificate is missing or has an empty value "
            "for a necessary field.");
        certificateErrors->Add(0x800B0109,
            "The certificate root is not trusted.");
        certificateErrors->Add(0x800B010C,
            "The certificate has been revoked.");
        certificateErrors->Add(0x800B010F,
            "The name in the certificate does not not match "
            "the host name requested by the client.");
        certificateErrors->Add(0x800B0111,
            "The certificate was explicitly marked "
            "as untrusted by the user.");
        certificateErrors->Add(0x800B0112,
            "A certification chain processed correctly, "
            "but one of the CA certificates is not trusted.");
        certificateErrors->Add(0x800B0113,
            "The certificate has an invalid policy.");
        certificateErrors->Add(0x800B0114,
            "The certificate name is either not "
            "in the permitted list or is explicitly excluded.");
        certificateErrors->Add(0x80092012,
            "The revocation function was unable to check "
            "revocation for the certificate.");
        certificateErrors->Add(0x80090327,
            "An unknown error occurred while "
            "processing the certificate.");
        certificateErrors->Add(0x80096001,
            "A system-level error occurred "
            "while verifying trust.");
        certificateErrors->Add(0x80096002,
            "The certificate for the signer of the message "
            "is invalid or not found.");
        certificateErrors->Add(0x80096003,
            "One of the counter signatures was invalid.");
        certificateErrors->Add(0x80096004,
            "The signature of the certificate "
            "cannot be verified.");
        certificateErrors->Add(0x80096005,
            "The time stamp signature or certificate "
            "could not be verified or is malformed.");
        certificateErrors->Add(0x80096010,
            "The digital signature of the object "
            "was not verified.");
        certificateErrors->Add(0x80096019,
            "The basic constraint extension of a certificate "
            "has not been observed.");
    }

    static String^ CertificateErrorDescription(UInt32 problem)
    {
        // Initialize the error message dictionary 
        // if it is not yet available.
        if (certificateErrors->Count == 0)
        {
            InitializeCertificateErrors();
        }

        String^ description = safe_cast<String^>(
            certificateErrors[problem]);
        if (description == nullptr)
        {
            description = String::Format(
                CultureInfo::CurrentCulture,
                "Unknown certificate error - 0x{0:x8}",
                problem);
        }

        return description;
    }

public:
    // The following method is invoked 
    // by the CertificateValidationDelegate.
static bool ValidateServerCertificate(
        Object^ sender,
        X509Certificate^ certificate,
        X509Chain^ chain,
        SslPolicyErrors sslPolicyErrors)
    {
    
        Console::WriteLine("Validating the server certificate.");
        if (sslPolicyErrors == SslPolicyErrors::None)
            return true;

        Console::WriteLine("Certificate error: {0}", sslPolicyErrors);

        // Do not allow this client to communicate with unauthenticated servers.
        return false;
    }

// The following method is invoked by the RemoteCertificateValidationDelegate.
public static bool ValidateServerCertificate(
      object sender,
      X509Certificate certificate,
      X509Chain chain,
      SslPolicyErrors sslPolicyErrors)
{
   if (sslPolicyErrors == SslPolicyErrors.None)
        return true;

    Console.WriteLine("Certificate error: {0}", sslPolicyErrors);

    // Do not allow this client to communicate with unauthenticated servers.
    return false;
}

Následující příklad kódu vytvoří delegát pomocí metody definované v předchozím příkladu kódu.

// Create a TCP/IP client socket.
// machineName is the host running the server application.
TcpClient^ client = gcnew TcpClient(machineName, 5000);
Console::WriteLine("Client connected.");
  
// Create an SSL stream that will close 
// the client's stream.
SslStream^ sslStream = gcnew SslStream(
    client->GetStream(), false,
    gcnew RemoteCertificateValidationCallback(ValidateServerCertificate),
    nullptr);
  
// The server name must match the name
// on the server certificate.
try
{
    sslStream->AuthenticateAsClient(serverName);
}
catch (AuthenticationException^ ex) 
{
    Console::WriteLine("Exception: {0}", ex->Message);
    if (ex->InnerException != nullptr)
    {
        Console::WriteLine("Inner exception: {0}", 
            ex->InnerException->Message);
    }

    Console::WriteLine("Authentication failed - "
        "closing the connection.");
    sslStream->Close();
    client->Close();
    return;
}

// Create a TCP/IP client socket.
// machineName is the host running the server application.
TcpClient client = new TcpClient(machineName,5000);
Console.WriteLine("Client connected.");
// Create an SSL stream that will close the client's stream.
SslStream sslStream = new SslStream(
    client.GetStream(),
    false,
    new RemoteCertificateValidationCallback (ValidateServerCertificate),
    null
    );
// The server name must match the name on the server certificate.
try
{
    sslStream.AuthenticateAsClient(serverName);
}
catch (AuthenticationException e)
{
    Console.WriteLine("Exception: {0}", e.Message);
    if (e.InnerException != null)
    {
        Console.WriteLine("Inner exception: {0}", e.InnerException.Message);
    }
    Console.WriteLine ("Authentication failed - closing the connection.");
    client.Close();
    return;
}

Poznámky

Argument delegáta sslPolicyErrors obsahuje všechny chyby certifikátu vrácené rozhraním SSPI při ověřování klienta nebo serveru. Hodnota Boolean vrácená metodou vyvolanou tímto delegátem určuje, zda je povoleno úspěšné ověření.

Tento delegát se používá s SslStream třídou .

Metody rozšíření

GetMethodInfo(Delegate)

Získá objekt, který představuje metodu reprezentovanou zadaným delegátem.

Viz také

• LocalCertificateSelectionCallback