With following code I am able to track public IP changes of my desktop application. This should be able to track if either the public IP changed or the user enabled a VPN to change his public IP. This code is run on application launch and used once again when a check is needed:
public class PublicIP
{
IPAddress last_ip=null;
DateTime timestamp_lastipchange;
public void UpdateIP()
{
List<string> hosts = new List<string>()
{
"https://api.ipify.org",
"https://ipinfo.io/ip",
"https://checkip.amazonaws.com",
"https://wtfismyip.com/text",
"http://icanhazip.com"
};
using(WebClient webclient = new WebClient())
{
foreach(string host in hosts)
{
//Download each string from hosts until an IP could be fetched
try{
var newip = IPAddress.Parse(webclient.DownloadString(service)); //Downloading the string
if(!newip.IsEqual(last_ip) && last_ip!=null) timestamp_lastipchange = DateTime.Now; //Check if the ip changed, if the last known ip does not exists skipp this step
last_ip = newip; //Save last known ip
return;
}
catch { }
}
}
}
}
This approach seems to work pretty well, however during UnitTesting some workflows do not fetch a new IP:
IP change by switching networks: change gets successfully detected
IP changed by provider: change gets successfully detected
VPN was enabled when the application was launched and is then turned off:
change gets successfully detected
VPN was disabled on application start and is turned on during runtime:
change does not get detected. Webclient.DownloadString() still returns the same IP as if the VPN was not enabled.
I am not really sure what is happening in workflow nr 4. Do I have to manually select the new network interface (VPN)? Or is this a caching problem on the client/server side?
WebClient is high-level and might using static pool behind-the-scene (and also deprecated). You might try using HttpClient instead, because HttpClient handle connection via its message handler, and the default one is not static, which means this should work:
using(var httpClient = new HttpClient())
{
var newip = IPAddress.Parse(webclient.GetStringAsync(service)
.ConfigureAwait(false).GetAwaiter().GetResult());
// ...
}
Related
I have been looking into how these two new settings will effect with our c# code that connects to an ldap server and performs user lookups
Using the code below to connect to an AD i have found a few scenarios that no longer work when these settings are switched on.
private static LdapConnection ConnectAndBind(
string server,
int port,
int timeout,
string userName,
string pwd,
AuthType authType,
bool useSSL,
bool useV3)
{
var con = new LdapConnection(new LdapDirectoryIdentifier(server, port));
if (useSSL)
{
con.SessionOptions.SecureSocketLayer = useSSL;
con.SessionOptions.VerifyServerCertificate = VerifyServerCertificate;
con.SessionOptions.QueryClientCertificate = QueryClientCertificate;
}
con.Timeout = new TimeSpan(0, 0, timeout);
con.SessionOptions.ProtocolVersion = useV3 ? 3 : 2;
try
{
con.AuthType = authType;
con.Credential = new NetworkCredential(userName, pwd);
con.Bind();
}
catch (Exception e)
{
throw new ProviderException(
ProviderException.ErrorIdentifier.AuthenticationFailed,
LanguageLogic.GetString("AuthenticationProvider.ConnectError"),
e.Message);
}
return con;
}
This is used in the context of a webforms/mvc asp.net (4.5) app once connected its used to import user details in the the app
but at the moment depending on how the registry keys for the two settings on the AD server are set i am finding some situations where it does not connect (the error returned is that the supplied credentials are invalid)
The first two tables are kinda how i expected it to work with non signed/non ssl basic bind not working
how ever i cannot find a reason why when the Channel binding is set to required (table 3) it does not work for the other 3 red entries
Has any one else been working on this that could shed some light on the matter. would newer version of .net support this setting.
Thanks for any info
UPDATE 1
so i downloaded Softerra LDAP browser. i get the same results using that . so i dont think its my code.
as soon as i turn on the reg key for Channel Binding i get the specified credentials are invalid for those connection methods over SSL
i have updated the AD server with all the latest patches but no change.
I am trying to host a webserver with WPF on the local wifi network and expose a webservice that another device (in my case, an Android) can call while connected to the same wifi network. I have created an inbound rule on the firewall for the port I am using. The webservice call only goes through when the windows app is launched using "Run as Administrator"
Is there a way I can do the same without Admin privileges?
Here is my code -
public class SelfHost
{
WebServiceHost Host;
public void HostServer()
{
var hostIPadd = Util.GetLocalHostIP(); //This returns something like "http://192.168.1.2"
Values.SERVER_PORT_VALUE = "55000";
var uri = new Uri(hostIPadd + ":" + Values.SERVER_PORT_VALUE);
Host = new WebServiceHost(new Service{...}, uri);
//Start host
ServiceEndpoint ep = Host.AddServiceEndpoint(typeof(IService), new WebHttpBinding(), "");
Host.Open();
}
}
public partial class MyWindow : Window
{
public MyWindow()
{
InitializeComponent();
StartHost();
}
private void StartHost()
{
var host = new SelfHost();
var thServer = new System.Threading.Thread(host.HostServer);
thServer.IsBackground = true;
thServer.Start();
}
}
I have created an inbound rule in the firewall with these properties
Protocol type - TCP
Local port - Specific Ports - 55000
Profiles - Public
Action - "Allow the connection"
Programs - "All programs that meet the specified conditions"
I don't quite know why the firewall ignores this exception if the app is not running in Admin. The WebServiceHost object runs fine even if it is not in Admin mode, no errors.
But the webservice call never reaches the server and the request times out.
nothing to do with the firewall, you can't open an http link in a wpf app - for security reasons
see that
I have four application server for my application.Application is working on all server using load balancing.If one of my server goes down I have to check it manually using my system hosts file.To avoid this manual process I have created one program using C#.I write server IP address one by one in host file and remove previous one.
private void RunWithUAC()
{
List<string> lstIPAddress = new List<string>();
lstIPAddress.Add("1.1.1.1 example.com");
lstIPAddress.Add("1.1.1.1 example.com");
lstIPAddress.Add("1.1.1.1 example.com");
lstIPAddress.Add("1.1.1.1 example.com");
var systemPath = Environment.GetFolderPath(Environment.SpecialFolder.System);
Console.WriteLine(systemPath);
var path = #"C:\Windows\System32\drivers\etc\hosts";
foreach (var item in lstIPAddress)
{
System.IO.File.WriteAllText(path, string.Empty);
try
{
File.WriteAllText(path, item);
WebRequest request = WebRequest.Create("https://example.com");
request.Timeout = 10000;
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
}
catch (Exception)
{
MessageBox.Show(item);
}
Thread.Sleep(1000);
}
}
But When second server goes down.It will give me timeout error for third server.
Please check the code and let me know what is wrong with this code.
Probably some kind of connection pooling, HTTP pipelining or keep-alive. This is the wrong approach in the first place.
Connect directly to the right IP (WebRequest.Create("https://1.1.1.1")). If you need to send a Host header add that manually to the request.
I tried to search for similar questions but I couldn't since I don't know how to pronounce this question.
My server codes for connection is...
server_Listener = new TcpListener(7778);
server_Listener.Start();
while (true)
{UserSocket user = new UserSocket();
try
{
user.client = server_Listener.AcceptSocket();
}
catch
{
break;
}
if (user.client.Connected)
{
user.server_isClientOnline = true;
this.BeginInvoke((MethodInvoker)(delegate()
{
textBox1.AppendText("client connected\n");
}));
user.server_netStream = new NetworkStream(user.client);
the UserSocket class has a Socket(variable name client), and a netStream (server_netStream) to get to receive and send packet data from clients.
My Question is, this works just fine on local connections, but it doesn't work non-locally.
I tried to access to this server using my laptop, and my friend's, but non of them worked.
Not an error although... but it just couldn't receive the connection.
Are my codes wrong? or are there a new way of getting connection non-locally?
It could be the firewall on your machine or some other issue on your network. You might want to try Wireshark (http://www.wireshark.org/) and see if you can glean any information that way.
I have been attempting to start an instance of EC2 in C# without luck.
When passing in an instance id to start the instance I get an error that the instance cannot be found despite that I am passing in an instance ID that I have obtained from the object property.
Amazon made huge efforts to integrate its AWS Cloud .Net SDK To VS2008 & VS 2010
1 - Download and Install the AWS SDK msi
2 - Create an AWS Console project, enter your credentials (available from your AWS Console under your login name menu on the top right corner)
3 - Add the following code (see below images).
4 - Your're done. It's very straightforward. You can check the programmatic start/stop success by refreshing your AWS Console Screen.
AmazonEC2 ec2 = AWSClientFactory.CreateAmazonEC2Client();
//Start Your Instance
ec2.StartInstances(new StartInstancesRequest().WithInstanceId("i-00000000"));
//Stop it
ec2.StopInstances(new StopInstancesRequest().WithInstanceId("i-00000000"));
You just need to replace "i-00000000" by your instance Id (available in your AWS Management Console)
Hope this helps those googling this and stumbling upon this question (as I did myself) start off quickly. Following these simple steps via these wizards will spare you considerable headaches.
Try something like this with the AWSSDK to start new instances of an "image id":
RunInstancesResponse response = Client.RunInstances(new RunInstancesRequest()
.WithImageId(ami_id)
.WithInstanceType(instance_type)
.WithKeyName(YOUR_KEYPAIR_NAME)
.WithMinCount(1)
.WithMaxCount(max_number_of_instances)
.WithUserData(Convert.ToBase64String(Encoding.UTF8.GetBytes(bootScript.Replace("\r", ""))))
);
(Note: The .WithUserData() is optional and is used above to pass a short shell script.)
If the call is successful the response should contain a list of instances. You can use something like this to create a list of "instance ids":
if (response.IsSetRunInstancesResult() && response.RunInstancesResult.IsSetReservation() && response.RunInstancesResult.Reservation.IsSetRunningInstance())
{
List<string> instance_ids = new List<string>();
foreach (RunningInstance ri in response.RunInstancesResult.Reservation.RunningInstance)
{
instance_ids.Add(ri.InstanceId);
}
// do something with instance_ids
...
}
Be mindful that Amazon AWS instances exist only in one region. If your instance id i-12345 is in the EU-West-1 region, and you just make a new EC2Client and tell the client to start i-12345 it may well complain that it cannot find that instance, because the client started up in the us-east-1 region, which does not have i-12345 instance.
Your call that creates the client should specify the region, if it is not the default region (I've no idea which AWS region is default, so I specify every time):
AmazonEC2 ec2 = AWSClientFactory.CreateAmazonEC2Client(
new Amazon.EC2.AmazonEC2Config().WithServiceURL("https://eu-west-1.ec2.amazonaws.com")
);
Ok, this is the FULL, end-to-end instructions.
1. Install AWSSDK.Core and AWSSDK.EC2 using Nuget Package Manager.
2. Then copy this whole class to your project. AccessKey and Secret are obtained in AWS IAM. You will need to ensure the user you create has "AmazonEC2FullAccess" (You can probably use a lower-level permission policy, I am just lazy here :D). region is your AW S EC2 instance region. and Instance ID can be found in the EC2 dashboard list. Simple, works perfectly... You can also write extra code to manage the response object.
3. Be mindful if you are behind a proxy, you will have to configure it (I havent included code here).
public class AWSClass : IDisposable
{
Amazon.EC2.AmazonEC2Client _client;
public AWSClass(string region, string AccessKey, string Secret)
{
RegionEndpoint EndPoint = RegionEndpoint.GetBySystemName(region);
Amazon.Runtime.BasicAWSCredentials Credentials = new Amazon.Runtime.BasicAWSCredentials(AccessKey, Secret);
_client = new AmazonEC2Client(Credentials, EndPoint);
}
public void Dispose()
{
_client = null;
}
public void StopInstance(string InstanceID)
{
StopInstancesResponse response = _client.StopInstances(new StopInstancesRequest
{
InstanceIds = new List<string> {InstanceID }
});
//Can also do something with the response object too
}
public void StartInstance(string InstanceID)
{
StartInstancesResponse response = _client.StartInstances(new StartInstancesRequest
{
InstanceIds = new List<string> { InstanceID }
});
}
}
try this.
var startRequest = new StartInstancesRequest
{
InstanceIds = new List<string>() { instanceId }
};
bool isError = true;
StartInstancesResponse startInstancesResponse = null;
while (isError)
{
try
{
startInstancesResponse=amazonEc2client.StartInstances(startRequest);
isError = false;
}
catch (Exception ex)
{
Console.WriteLine(ex.Message + "\n" + ex.StackTrace);
isError = true;
}
}