SSL TCP SslStream服务器抛出未处理的异常“”；System.Security.Cryptography.

我正试图创建一个C#TCP服务器，以便在Windows 2008服务器上使用SslStream从发送TCP数据的客户端（目标C移动应用程序）接收TCP数据。

我使用的是微软的示例代码（注意：我对该代码的修改版本在这个问题的末尾），即它是服务器代码，就在"下面的代码示例演示创建一个TcpListener，它使用SslStream类与客户端通信"）

例外

然而，当我运行这个服务器代码时，我会得到以下异常：

System.Security.Cryptography.CryptographicException: Cannot find the original si
gner.
   at System.Security.Cryptography.CryptographicException.ThrowCryptographicExce
ption(Int32 hr)
   at System.Security.Cryptography.X509Certificates.X509Utils._LoadCertFromFile(
String fileName, IntPtr password, UInt32 dwFlags, Boolean persistKeySet, SafeCer
tContextHandle& pCertCtx)
   at System.Security.Cryptography.X509Certificates.X509Certificate.LoadCertific
ateFromFile(String fileName, Object password, X509KeyStorageFlags keyStorageFlag
s)
   at System.Security.Cryptography.X509Certificates.X509Certificate.CreateFromCe
rtFile(String filename)
   at SslTcpServer.LocationSslTcpServer.RunServer(String certificate) in c:'SslTcpServer'Program.cs:line 20
   at SslTcpServer.Program.Main(String[] args) in c:'SslTcpServer'Program.cs:line 180

我也在http://msdn.microsoft.com/en-us/library/system.security.cryptography.x509certificates.x509certificate.aspx它抛出了一个类似的异常。

附加信息

我从NameCheap获得了SSL证书。我购买了EssentialSSL通配符证书。我在Windows 2008服务器上进行了创建证书请求，即以开头的gaint文本

    -----BEGIN NEW CERTIFICATE REQUEST-----
            alots of random characters
    -----END NEW CERTIFICATE REQUEST-----

并将该gaint文本文件上传到NameCheap，并通过电子邮件收到一个Certificate.cer文件。

我的代码

public sealed class LocationSslTcpServer
{
    static X509Certificate serverCertificate = null;
    // The certificate parameter specifies the name of the file 
    // containing the machine certificate.
    public static void RunServer(string certificate)
    {
        serverCertificate = X509Certificate.CreateFromCertFile(certificate);
        // Create a TCP/IP (IPv4) socket and listen for incoming connections.
        TcpListener listener = new TcpListener(IPAddress.Any, 8080);
        listener.Start();
        while (true)
        {
            Console.WriteLine("Waiting for a client to connect...");
            // Application blocks while waiting for an incoming connection.
            // Type CNTL-C to terminate the server.
            TcpClient client = listener.AcceptTcpClient();
            ProcessClient(client);
        }
    }
    static void ProcessClient(TcpClient client)
    {
        // A client has connected. Create the 
        // SslStream using the client's network stream.
        SslStream sslStream = new SslStream(
            client.GetStream(), false);
        // Authenticate the server but don't require the client to authenticate.
        try
        {
            sslStream.AuthenticateAsServer(serverCertificate,
                false, SslProtocols.Tls, true);
            // Display the properties and settings for the authenticated stream.
            DisplaySecurityLevel(sslStream);
            DisplaySecurityServices(sslStream);
            DisplayCertificateInformation(sslStream);
            DisplayStreamProperties(sslStream);
            // Set timeouts for the read and write to 5 seconds.
            sslStream.ReadTimeout = 5000;
            sslStream.WriteTimeout = 5000;
            // Read a message from the client.   
            Console.WriteLine("Waiting for client message...");
            string messageData = ReadMessage(sslStream);
            Console.WriteLine("Received: {0}", messageData);
            // Write a message to the client.
            byte[] message = Encoding.UTF8.GetBytes("Hello from the server.<EOF>");
            Console.WriteLine("Sending hello message.");
            sslStream.Write(message);
        }
        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.");
            sslStream.Close();
            client.Close();
            return;
        }
        finally
        {
            // The client stream will be closed with the sslStream
            // because we specified this behavior when creating
            // the sslStream.
            sslStream.Close();
            client.Close();
        }
    }
    static string ReadMessage(SslStream sslStream)
    {
        // Read the  message sent by the client.
        // The client signals the end of the message using the
        // "<EOF>" marker.
        byte[] buffer = new byte[2048];
        StringBuilder messageData = new StringBuilder();
        int bytes = -1;
        do
        {
            // Read the client's test message.
            bytes = sslStream.Read(buffer, 0, buffer.Length);
            // Use Decoder class to convert from bytes to UTF8
            // in case a character spans two buffers.
            Decoder decoder = Encoding.UTF8.GetDecoder();
            char[] chars = new char[decoder.GetCharCount(buffer, 0, bytes)];
            decoder.GetChars(buffer, 0, bytes, chars, 0);
            messageData.Append(chars);
            // Check for EOF or an empty message.
            if (messageData.ToString().IndexOf("<EOF>") != -1)
            {
                break;
            }
        } while (bytes != 0);
        return messageData.ToString();
    }
    static void DisplaySecurityLevel(SslStream stream)
    {
        Console.WriteLine("Cipher: {0} strength {1}", stream.CipherAlgorithm, stream.CipherStrength);
        Console.WriteLine("Hash: {0} strength {1}", stream.HashAlgorithm, stream.HashStrength);
        Console.WriteLine("Key exchange: {0} strength {1}", stream.KeyExchangeAlgorithm, stream.KeyExchangeStrength);
        Console.WriteLine("Protocol: {0}", stream.SslProtocol);
    }
    static void DisplaySecurityServices(SslStream stream)
    {
        Console.WriteLine("Is authenticated: {0} as server? {1}", stream.IsAuthenticated, stream.IsServer);
        Console.WriteLine("IsSigned: {0}", stream.IsSigned);
        Console.WriteLine("Is Encrypted: {0}", stream.IsEncrypted);
    }
    static void DisplayStreamProperties(SslStream stream)
    {
        Console.WriteLine("Can read: {0}, write {1}", stream.CanRead, stream.CanWrite);
        Console.WriteLine("Can timeout: {0}", stream.CanTimeout);
    }
    static void DisplayCertificateInformation(SslStream stream)
    {
        Console.WriteLine("Certificate revocation list checked: {0}", stream.CheckCertRevocationStatus);
        X509Certificate localCertificate = stream.LocalCertificate;
        if (stream.LocalCertificate != null)
        {
            Console.WriteLine("Local cert was issued to {0} and is valid from {1} until {2}.",
                localCertificate.Subject,
                localCertificate.GetEffectiveDateString(),
                localCertificate.GetExpirationDateString());
        }
        else
        {
            Console.WriteLine("Local certificate is null.");
        }
        // Display the properties of the client's certificate.
        X509Certificate remoteCertificate = stream.RemoteCertificate;
        if (stream.RemoteCertificate != null)
        {
            Console.WriteLine("Remote cert was issued to {0} and is valid from {1} until {2}.",
                remoteCertificate.Subject,
                remoteCertificate.GetEffectiveDateString(),
                remoteCertificate.GetExpirationDateString());
        }
        else
        {
            Console.WriteLine("Remote certificate is null.");
        }
    }
    public static void DisplayUsage()
    {
        Console.WriteLine("To start the server specify:");
        Console.WriteLine("serverSync certificateFile.cer");
        Environment.Exit(1);
    }
}
class Program
{
    static int Main(string[] args)
    {
        string certificate = null;
  
        certificate = "Certificate.cer";
        try
        {
            LocationSslTcpServer.RunServer(certificate);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.StackTrace);
            Console.ReadLine();
        }
        return 0;
        
    }
}

提前感谢您的帮助！