【发布时间】：2016-06-21 18:40:44
【问题描述】：
我正在尝试创建自己的 HTTPS 代理服务器。 出于某种原因，当我尝试从 sslstream 对象中读取数据时出现异常。 就是这样：
System.dll 中出现“System.IO.IOException”类型的未处理异常
附加信息：无法从传输连接中读取数据：连接尝试失败，因为连接方在一段时间后没有正确响应，或者建立连接失败，因为连接的主机没有响应。
这是我的代码：
public Server()
{
m_portnumber = 4434;
m_tcplistener = new TcpListener(IPAddress.Any, m_portnumber);
m_cert = createCertificate();
}
public void start()
{
m_tcplistener.Start();
while (true)
{
TcpClient client = m_tcplistener.AcceptTcpClient();
ClientHandler(client);
}
}
private void ClientHandler(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(m_cert,
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);
}
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 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);
// 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.
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.");
}
}
private static void DisplayUsage()
{
Console.WriteLine("To start the server specify:");
Console.WriteLine("serverSync certificateFile.cer");
Environment.Exit(1);
}
private X509Certificate createCertificate()
{
byte[] c = Certificate.CreateSelfSignCertificatePfx(
"CN=localhost", //host name
DateTime.Parse("2015-01-01"), //not valid before
DateTime.Parse("2020-01-01"), //not valid after
"sslpass"); //password to encrypt key file
using (BinaryWriter binWriter = new BinaryWriter(File.Open(@"cert.pfx", FileMode.Create)))
{
binWriter.Write(c);
}
return new X509Certificate2(@"cert.pfx", "sslpass");
}
}
【问题讨论】：
-
该行出现问题：bytes = sslStream.Read(buffer, 0, buffer.Length);
-
当然可以。您设置了读取超时，MSDN 说“如果读取操作未在此属性指定的时间内完成，则读取操作将引发 IOException。”你预计会发生什么？
-
（如果您希望使用
messageData.ToString().IndexOf("<EOF>")检测 EOF，那么只有在客户端向您发送字节<EOF>时才会受到影响。您的客户端是否这样做？因为我怀疑您的客户端是一个网络浏览器，我怀疑它是。） -
实际上客户端向我发送了 url，我需要与服务器建立连接（通过我）。那我到底应该怎么做？
-
我确定它永远不会站在 EOF 线上。它总是通过异常之前
标签： c# ioexception sslstream