RemoteCertificateValidationCallback 代理人

定義

名前空間:

System.Net.Security

アセンブリ:

System.Net.Security.dll

認証に使用されるリモートの SSL (Secure Sockets Layer) 証明書を検証します。

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 

パラメーター

sender

Object

この検証のステータス情報を格納するオブジェクト。

certificate

X509Certificate

リモート側の認証に使用される証明書。

chain

X509Chain

リモートの証明書に関連付けられた証明機関のチェーン。

sslPolicyErrors

SslPolicyErrors

リモートの証明書に関連付けられた 1 つ以上のエラー。

戻り値

Boolean

指定した証明書が認証に使用できるかどうかを判断する Boolean 値。

例

次のコード例では、 クラスのインスタンスによって呼び出されるメソッドを RemoteCertificateValidationCallback 実装します。 検証エラーがある場合、このメソッドはそれらを表示し、 を返 falseします。これにより、認証されていないサーバーとの通信が禁止されます。

    // 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            "The certificate has been revoked.");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;
}

次のコード例では、前のコード例で定義した メソッドを使用してデリゲートを作成します。

// 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;
}

注釈

デリゲートの引数には、クライアントまたはサーバーの sslPolicyErrors 認証中に SSPI によって返された証明書エラーが含まれます。 Booleanこのデリゲートによって呼び出されたメソッドによって返される値によって、認証が成功するかどうかが決まります。

このデリゲートは、 クラスで使用されます SslStream 。

拡張メソッド

GetMethodInfo(Delegate)

指定したデリゲートによって表されるメソッドを表すオブジェクトを取得します。

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• LocalCertificateSelectionCallback