无法让 C# SslStream 与我的 X509 证书一起使用

Question

我对安全和加密有点陌生，所以如果我犯了一个非常愚蠢的错误，请提前道歉。 我需要一个服务器和一个客户端通过使用 SslStream 的安全连接进行通信。但是我的证书不起作用。我收到以下错误：System.NotSupportedException: 'The server mode SSL must use a certificate with the associated private key.' 我的代码是文档中给出的微软示例：https://docs.microsoft.com/en-us/dotnet/api/system.net.security.sslstream?view=netframework-4.8ss

我试过了：

• 使用 makecert 自行烧录的证书（例如在这篇文章中：SSLStream example - how do I get certificates that work?）
• OpenSSL 证书
• 本站流程：http://www.reliablesoftware.com/DasBlog/PermaLink,guid,6507b2c6-473e-4ddc-9e66-8a161e5df6e9.aspx
• 使用 .pfx 文件而不是 .cer 文件（如本文中：X509Certificate2 the server mode SSL must use a certificate with the associated private key），但出现以下异常：Win32Exception: The certificate chain was issued by an authority that is not trusted.

除了最后一个之外，所有的都给出了System.NotSupportedException: 'The server mode SSL must use a certificate with the associated private key.' 异常。 这是否意味着自签名证书不起作用？我需要购买证书吗？

编辑： 这是我使用的代码。这是修改后的示例（对不起，如果我的代码很糟糕）并且是可执行的，模拟服务器和客户端并抛出异常：

class Program
{

    static void Main(string[] args)
    {
        //Temporarily added the arguments here for you to see
        args = new string[2] { @"C:\Users\jacke\Documents\CA\TempCert.cer", "FakeServerName" };
        Console.WriteLine("Starting server in seperate thread...");
        Task t = Task.Run(() => { Server.Initialize(args[0]); });
        Task.Delay(500).Wait();
        Client.RunClient(args[1]);
    }
}

public static class Server
{
    private static X509Certificate cert;
    private static TcpListener server;

    public static void Initialize(string certificate)
    {
        cert = X509Certificate.CreateFromCertFile(certificate);
        server = new TcpListener(IPAddress.Any, 12321);
        server.Start();
        while (true)
        {
            Console.WriteLine("Waiting for a client to connect...");

            TcpClient client = server.AcceptTcpClient();
            ProcessClient(client);
        }
    }


    private static void ProcessClient(TcpClient client)
    {

        SslStream sslStream = new SslStream(client.GetStream(), false);
        try
        {
            sslStream.AuthenticateAsServer(cert, clientCertificateRequired: false, checkCertificateRevocation: true);
            sslStream.ReadTimeout = 5000;
            sslStream.WriteTimeout = 5000;   
            Console.WriteLine("Waiting for client message...");
            string messageData = Helpers.ReadMessage(sslStream);
            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
        {                
            sslStream.Close();
            client.Close();
        }
    }



}

public static class Client
{
    private static Hashtable certificateErrors = new Hashtable();
    public static bool ValidateServerCertificate(
          object sender,
          X509Certificate certificate,
          X509Chain chain,
          SslPolicyErrors sslPolicyErrors)
    {
        if (sslPolicyErrors == SslPolicyErrors.None)
            return true;

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


    public static void RunClient(string serverName)
    {
        TcpClient client = new TcpClient("localhost", 12321);
        Console.WriteLine("Client connected.");
        SslStream sslStream = new SslStream(
            client.GetStream(),
            false,
            new RemoteCertificateValidationCallback(ValidateServerCertificate),
            null
            );
        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;
        }
        byte[] messsage = Encoding.UTF8.GetBytes("Hello from the client.<EOF>");
        sslStream.Write(messsage);
        string serverMessage = Helpers.ReadMessage(sslStream);
        Console.WriteLine("Server says: {0}", serverMessage);

        client.Close();
        Console.WriteLine("Client closed.");
    }


}

public static class Helpers
{
    public static string ReadMessage(SslStream sslStream)
    {
        // Read the  message sent by the server.
        // The end of the message is signaled using the
        // "<EOF>" marker.
        byte[] buffer = new byte[2048];
        StringBuilder messageData = new StringBuilder();
        int bytes = -1;
        do
        {
            bytes = sslStream.Read(buffer, 0, buffer.Length);
            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.
            if (messageData.ToString().IndexOf("<EOF>") != -1)
            {
                break;
            }
        } while (bytes != 0);

        return messageData.ToString();
    }
}

这是我创建证书的方式（如我上面链接的帖子中所述）：

makecert -sv RootCATest.pvk -r -n "CN=FakeServerName" RootCATest.cer
makecert -ic RootCATest.cer -iv RootCATest.pvk -n "CN=FakeServerName" -sv
TempCert.pvk -pe -sky exchange TempCert.cer
cert2spc TempCert.cer TempCert.spc
pvkimprt -pfx TempCert.spc TempCert.pvk

我使用上述命令输入的其他信息：

• 当前 2 个命令要求输入密码时，我将其留空
• 我检查了导出私钥并将“A”设置为最后一个命令的密码

然后我将 .pfx 文件导入本地证书存储（我之前也尝试过机器范围）并让程序选择正确的存储。它警告我 CA 的所有证书都是可信的，我应该联系 CA 以检查这确实是他们的证书，但我继续。然后我运行代码（使用我刚刚创建的“TempCert.cer”文件）并得到了错误。任何建议都非常感谢！

Answer 1

如果我没记错的话，.cer 文件不包含私钥，并且我假设通过从文件加载证书，不会检查证书存储。您可以导出 .pfx 并在导出中包含私钥。

我不知道为什么.pvk 尝试失败（我自己从未尝试过这种格式）-SslStream 绝对可以使用自签名证书；客户端只需忽略验证失败。

但是如果你已经将它导入到商店中，你应该可以直接加载它：

using System.Security.Cryptography.X509Certificates;

// ...

using (X509Store store = new X509Store(StoreName.My, StoreLocation.LocalMachine))
{
    store.Open(OpenFlags.ReadOnly);
    var certs = store.Certificates.Find(X509FindType.FindBySubjectName, "FakeServerName", false);
    return new X509Certificate2(certs[0]);
}

回应您评论中的错误：

无法识别提供给包的凭据

我不知道我是否收到了确切的消息，但我确实记得必须授予应用程序遇到的用户访问权限。您必须打开正确证书工具：

https://docs.microsoft.com/en-us/dotnet/framework/wcf/feature-details/how-to-view-certificates-with-the-mmc-snap-in （运行 mmc，选择文件/添加管理单元，选择证书）

然后授予用户对私钥的访问权限：

https://docs.secureauth.com/display/KBA/Grant+Permission+to+Use+Signing+Certificate+Private+Key （右键证书，选择所有任务/管理私钥）