Talal khan

ASP.net Client side validation textbox highlight not working

2012-07-10T14:09:00.002-04:00

If you are wondering why your text boxes are not highlighted(red border) when your client validations is on there is a validation message but no red border besides everything looks perfect.
I am not going into detail but your validation(highlighting of border) depends on the CSS class(s) called

.input-validation-error

{

border: 1px solid #ff0000;

background-color: #ffeeee;

}

Like me tell you if you are expecting this should automagically work then you are wrong. The CSS class that comes with MVC 3 has a bug in it.

This CSS class will take no effect because the following with take precedence and override this class.

input[type="text"], input[type="password"]

{

border: 1px solid #c9d7e1;

padding: 2px;

font-size: 1.2em;

color: #444;

width: 200px;

}

Due to this you can see in View Source that the textbox or other html controls has this CSS class in it but has not effect(no red border)

Now if you want to do a quick fix there are two possibilities.

Create another class like this

input[type="text"].input-validation-error

{

border: thick solid #ff0000;

background-color: #FFC0CB;

}
Or use the !important keyword to add value to your validation class, like this.
.input-validation-error

{

border: 1px solid #ff0000!important;

background-color: #ffeeee;

}

Save your CSS file and rerun the app. Now upon validation you should see a red border around your textbox.
Again the perquisite of this article is if everything works on client validation except red border.
If you still didn't see then your client side validation is not working. That's beyond the scope of this article.

How to Turn on WCF Tracing in 2 steps

2012-05-31T12:50:00.000-04:00

There are two steps to turn on WCF tracing.
First is to add a source as shown below inside 'Configuration' element

<system.diagnostics>

<add

name="messages"

type="System.Diagnostics.XmlWriterTraceListener"

initializeData="Messages.svclog" />

listeners>

source>

sources>

system.diagnostics>

And second is to put the following inside the 'System.ServiceModel' element to start tracing.

<messageLogging

logEntireMessage="true"

logMalformedMessages="true"

logMessagesAtServiceLevel="true"

logMessagesAtTransportLevel="false"

maxMessagesToLog="0x7fffffff"

maxSizeOfMessageToLog="0x7fffffff"/>

diagnostics>

After that your messages will be logged into a file called Messages.svclog.

Disabling ViewState not working in ASP.net

2011-12-09T15:37:00.001-05:00

I have conducted many interviews, talked to the seasoned and experience .net developers and guess what 99% of them were confident enough to tell me that if you disable the view state of a asp.net control your data for that control won't be post back to server. If you are one of that 99%, you need to read that it is not true 'completely'.
ASP.net is build on the top of HTTP so it inherits some of the property of HTTP protocol. One of that property is HTTP is stateless so is ASP.net states are maintained in different ways in ASP.net. One of them is view state.
Before I prove my point, I want you to do this.

Create a brand new ASP.NET Web Site project.
In Default.aspx, drop one asp.net text box & one asp.net button control on this page.
Disable the view state of whole page by placing EnableViewState="false" in the page directives.
Disable the view state of Form by enableviewstate="false" property.
Disable the view state of text box by enableviewstate="false" property.
Go to Page_Load function of Default.aspx and write the following code.

protected void Page_Load(object sender, EventArgs e)

{
if (IsPostBack)
{
System.Web.HttpContext.Current.Response.Write(@"<script javascript""="" language=""> alert('" + TextBox1.Text + "') </script>");
}
}
Run the application and type something in the text box and press enter or click the button to post it back to the server.I am confident enough that your data will be displayed in alert box though you have disabled the viewstate of whole page, form and textbox control.

I understand that you must be thinking this is bug or something but it is not. I will explain it in the bottom section but for right now I want you to drop a asp.net label control and disable its view state by enableviewstate="false.
Now add the following lines in your Page_Load event and re run the applicaiton.

if (IsPostBack)

{

System.Web.HttpContext.Current.Response.Write(@"<SCRIPT LANGUAGE=""JavaScript"">alert('" + Label1.Text + "')</SCRIPT>");

Label1.Text = "My label";

}

Click on Button to post back the page. You will see an alert box with the lable's text property as "Label". In the above code, we have actually changed the label's text property to "My Label" after the first post back. You see that now label's text property is "My Label" displayed on the page. Hit the button one more time. This time you will see that since the view state of label's control is disabled, asp.net set the default value of label's control "Label" instead of "My Label". Therefore when the 2nd post back occur we see "Label" on alert box .

Go ahead and turn on the view state of the label, first make sure the page's & Form's view state property is set to true too otherwise childlren control's view state property won't work.
Rerun the application and click on the button for first time to let the label change its text to "My Label".This time the alert box displayed "Label",which is expected. Click on button 2nd time. Aha! did you see that now asp.net retains the value of this label's text property and showed us "My Label"?
Do the same thing for textbox. Enable the viewstate property of textbox and try it. You won't find a difference. Confused?

Well this incident was reported back to Microsoft years ago and here is the justification of what Microsoft says about it. Please go ahead and read it thoroughly. Yes, there are 3 server controls i.e textbox, checkbox and radio button who retains their value from forms collection even if you disable the view state of them.But there are certain attributes of these control which can't function properly without Viewstate.

The articles says that this incident applies to .net 1.0 and 1.1. But for sure this works till 4.0. They just didn't get time to update it.

How to access a private member outside a class

2011-11-16T15:14:00.000-05:00

There is a misconception between C# developers that member access specifier like Private restricts the accessibility outside of that class where it is declared.

Today I am going to show you that it is possible via reflection to not only access those private members but you can change and manipulate them as you want.

Here is the link from Microsoft that tells us something about member access specifiers.

http://msdn.microsoft.com/en-us/library/ms173121.aspx

Worth noting the definition of Private access specifier

private: The type or member can be accessed only by code in the same class or struct

Alright, Lets jump on to the code to demonstrate how to access private member.

Lets create a Console Application and name it as ReflecitonDemo. Put the solution name AccessingPrivate.

Right click on ReflectionDemo project to add a class. Let's name it as SampleClass.

Type or paste the following snippet into SampleClass

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace ReflectionDemo

{

class SampleClass

{

private string privateVariable = "Hey! I am private string variable of SampleClass";

private String PrivateProperty

{

get

{

return privateVariable;

}

set

{

privateVariable = value;

}

private string PrivateMethod()

{

return "Hey! I am private Method of SampleClass.";

}

As you can see this class has 3 private members. A variable, property that uses that string variable and a private method that returns a string.

Double click on your Program.cs file and write/paste the following code in it.

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Reflection;

using Payroll;

namespace ReflectionDemo

{

class Program

{

static string decorator="**************************************************************";

static void ShowMemembers(object type)

{

Console.WriteLine("Showing all the members of " +type.GetType().Name+" class");

foreach (MemberInfo m in type.GetType().GetMembers(BindingFlags.Instance | BindingFlags.NonPublic|BindingFlags.DeclaredOnly))

{

Console.WriteLine(m.Name);

}

Console.WriteLine(decorator);

Console.ReadLine();

}

static void InvokePrivateMethod(object type,string methodName)

{

//Let's inovke the private method of this class

Console.WriteLine(decorator);

Console.WriteLine( type.GetType().GetMethod(methodName,BindingFlags.Instance|BindingFlags.NonPublic|BindingFlags.InvokeMethod|BindingFlags.DeclaredOnly).Invoke(type, null));

Console.WriteLine(decorator);

Console.ReadLine();

}

private static void ChangePrivateField(Object type, string fieldName,object newValue)

{

FieldInfo field = type.GetType().GetField(fieldName,BindingFlags.Instance|BindingFlags.NonPublic|BindingFlags.DeclaredOnly);

Console.WriteLine("Old value of private field: '{0}' of Class {1} is :\r\n ",fieldName,type.GetType().Name);

Console.WriteLine(decorator);

Console.WriteLine(field.GetValue(type));

Console.WriteLine(decorator);

field.SetValue(type, newValue);

//Lets see what we did with poor private variable.

Console.WriteLine("New value of private field: '{0}' of Class {1} is :\r\n ", fieldName, type.GetType().Name);

Console.WriteLine(decorator);

Console.WriteLine(type.GetType().GetField(fieldName, BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.InvokeMethod | BindingFlags.DeclaredOnly).GetValue(type));

Console.WriteLine(decorator);

Console.ReadLine();

}

static void Main(string[] args)

{

//http://msdn.microsoft.com/en-us/library/ms173121.aspx

SampleClass sc = new SampleClass();

ShowMemembers(sc);

Console.WriteLine("Calling Private method of SampleClass");

InvokePrivateMethod(sc, "PrivateMethod");

Console.WriteLine("Calling Private variable of SampleClass");

ChangePrivateField(sc, "privateVariable","Your wish my command");

Console.Clear();

List<string> list = new List<string>();

list.Add("Talal");

list.Add("Khan");

Console.WriteLine(decorator);

Console.WriteLine("List count is: {0}", list.Count);

Console.WriteLine(decorator);

Console.ReadLine();

Console.Clear();

ShowMemembers(list);

ChangePrivateField(list, "_size",10);

Console.WriteLine(decorator);

Console.WriteLine("List count is: {0}", list.Count);

Console.WriteLine(decorator);

Console.Clear();

Employee John = new Employee();

John.EmployeeId = 1001;

John.FirstName = "John";

John.LastName = "Teddy";

John.Address = "122 Awesome drive, Richmond, VA, 23238";

John.GetEmployeeSalarybyID(John.EmployeeId);

Console.WriteLine(John.Salary.ToString());

Employee Mary = new Employee();

Mary.EmployeeId = 1002;

John.FirstName = "Mary";

John.LastName = "Jones";

John.Address = "1345 Noway drive, Richmond, VA, 23238";

Mary.GetEmployeeSalarybyID(Mary.EmployeeId);

Console.WriteLine(Mary.Salary.ToString());

Employee Talal = new Employee();

Talal.EmployeeId = 1003;

John.FirstName = "Talal";

John.LastName = "Khan";

John.Address = "900 pump road, Richmond, VA, 23238";

Talal.GetEmployeeSalarybyID(Talal.EmployeeId);

Console.WriteLine(Talal.Salary.ToString());

ChangePrivateField(Talal, "_Salary", 99999.99);

Console.WriteLine(Talal.Salary.ToString());

Console.ReadLine();

}

The point of interest in this code snippets are three static methods named

ShowMemembers
InvokePrivateMethod
ChangePrivateField

The names are pretty self explanatory.

Let's jump on these method and see what they does.

ShowMembers Function; This method uses reflection to show only private members of a type that is passed as its parameter.In our above code, we are passing SampleClass type to this method as parameter.

The output if you run the project will show you all the private members defined only in this type, no inherited or child's type members will be shown.

Let's dig into this function line by line.

Console.WriteLine("Showing all the members of " +type.GetType().Name+" class");

This line is self explanatory. This line will display a string on console that says "Showing all the members of SampleClass class".

foreach (MemberInfo m in type.GetType().GetMembers(BindingFlags.Instance | BindingFlags.NonPublic|BindingFlags.DeclaredOnly))

{

Console.WriteLine(m.Name);

}

Ah! The following code snippet is what you need to access the private members of a type. As you can see in this code, reflection is being used to get the type of the type that has been passed as a parameter and then once we found that type, we use a built in function called GetMemebers() which is a overloaded method to return an array of string. This method takes BindingFlags enum type as a parameter. Now that our motive is to get all the private member of this type only, we have to use bit-wise shift operator for BindingFlags.
That's why I have used, Instance, NonPublic(for priavate Members) and DeclaredOnly(only from this type) flag. You can see the details of each flag on MSDN site here.

Guess what, this code will spits out the following output on console.

If you look closely in Sample class we have defined only 3 private members. Private variable, private property and private method. but the output shows 2 more properties; get_PrivateProperty & set_PrivateProperty. Remember, in .Net a property is nothing but combination of merely a getter and setter function.
Alright, now that we have seen all the private members of this class let's jump to next function called InvokePrivateMethod.

InvokePrivateMethod Function:
This method also uses reflection to invoke a private method. Once you have identified the name of the private function as in our case it is "PrivateMethod", We pass this alone with the object to invoke it.
Let's dig into this code base.

Console.WriteLine( type.GetType().GetMethod(methodName,BindingFlags.Instance|BindingFlags.NonPublic|BindingFlags.InvokeMethod|BindingFlags.DeclaredOnly).Invoke(type, null));

As you can see the above line uses a built in overloaded function GetMethod which uses two parameters, name of parameter and binding flag to reach out that function.
In addition to the binding flags that we discussed previous we have used another binding flag called BindingFlags.InvokeMethod which is used to tell the compiler that this method is to be invoked.
Once we get the required method from GetMethod(), we use Invoke function of MethodBase class to invoke this method and pass the object(in this case SampleClass).
The following is the output on the console.

Did you see, we called a private method named PrivateMethod of class SampleClass. Impressive?

ChangePrivateField Function:
As it name indicates this generic method I have created is used to change the value of any private field in any class. You can see the default value of string (privateVariable) in SampleClass is "Hey! I am private string variable of SampleClass". By calling this method, I am able to change that string to "Your wish is my command".
Let's see how.

FieldInfo field = type.GetType().GetField(fieldName,BindingFlags.Instance|BindingFlags.NonPublic|BindingFlags.DeclaredOnly);

This code is being used to get the private field of the SampleClass and store the reference in FieldInfo type. Now that we have got the private field, we can get its current value.

field.GetValue(type));

Now, I can see what you are thinking. If you can get the value, can we set the value? Sure, why not.
There is method called SetValue that you can use to change its value.

field.SetValue(type, newValue);

As you can see, this method expect two parameter, the object to which this field belong and new value.
Here is the output of this method on the console.

Now that we have learned how to manipulate these private field. Do you want to try this technique to some of the classes shipped with .Net such as List class?

Alright then, lets declare a list of string and add 2 string to that list as show below.

Console.Clear();

List<string> list = new List<string>();

list.Add("Talal");

list.Add("Khan");

Console.WriteLine(decorator);

Console.WriteLine("List count is: {0}", list.Count);

Console.WriteLine(decorator);

The output of this code should be 2. No tricks in there.
Now lets call ShowMembers function and pass this list object to that method.
You will get a list of all the private members as expected. Now that I pick _size variable from those private members list.
This is private variable of type int which Count read-only property uses to display you the count. I want to mess with it. I want to change the count from 2 to 200. Can I do that? Well before reading this article you probably would say No. But now your answer would be yes.
Call ChangePrivateField with list object, _size as fieldName, and 200 as new value.

ChangePrivateField(list, "_size",200);

Now output the count again.

Console.WriteLine(decorator);

Console.WriteLine("List count is: {0}", list.Count);

Console.WriteLine(decorator);

What did you see? 200 or 2 :)
Okay fair enough, you can now play with any type that has reflection permission on it or the type's code is not obfuscated.
Cheers.

Source Code

Hosting Https SSL WCF as a Windows Service

2010-02-23T23:00:00.000-05:00

There may have various reason where you opt to host a SSL WCF service as Windows Service compare to IIS. One of those reason is existing TCP service for internal folks and now you want to expose it to a web. Well, ideal way is to open another https endpoint. Now a general consensus among developers is TCP should be hosted in Windows service and HTTP(S) in IIS. So now that you have two endpoints TCP and HTTPS, IIS 6.0 and below doesn't fit your need.
Plus, you have a service hosted on windows service, running under TCP for a long time, well tested and doing good its job. This is the ideal scenario where you need this path.

Alright, without wasting a single minute on it, let jump to the code. In order to accomplish this task, you need the following ingredients.

A WCF that has been secured by Transport Layer Security mode.
A Windows Service to host this service.
Server, client and trust root certificates for trust chain.
Httpcfg.exe utitly.
A client, console application that uses client certificate to call this secure service.

If you don't have these ingredients, please read this tutorial from this point. Otherwise jump to the section "Configuring HTTPS WCF Service with Httpcfg.exeutility".

Creating aWCF Service

Create a new C# Class Library project. Name it as Service. Since you arecreating a new Project, a new solution will also be created. Select the location of thisproject/solution file and rename the solution WCF or something of your own choice.

Click OK.

Let’s quicklyrename the Class1.cs file to something like Calculator in Service project. Make sure the classname also changes to Calculator.

Don’t forget to add System.ServiceModel.dll as areference to Service project as shown below.

Now let’s addcouple of methods in it such as Add () and Subtract (). Pretty basic, huh?

Please copyand paste the following code in your Calculator.cs to save time.

using System;

usingSystem.Collections.Generic;

using System.Linq;

using System.Text;

using System.ServiceModel;

namespace Service

{

[ServiceContract]

public classCalculator

{

[OperationContract]

public intAdd(int x, inty)

{

returnx + y;

}

[OperationContract]

public intSubtract(int x, inty)

{

returnx - y;

}

Note: You can create your own WCF by any mean, but for this tutorial please follow the one.

Okay. Now at this point we have created a simple WCFservice that has 2 methods for Addition and Subtraction.

Let’s now Create a Windows Service that will host thisWCF service.

Right click on your WCF solution file and select Add New Project then select Windows Service.

Alright now we have 2 projects in our solution. First oneis WCF service and 2nd one is Windows Service.

Hosting WCF serivce under Windows Service

Double Click on Service1.cs file in WindowsServiceproject go open the file in Design mode. Then right click on design mode andselect Add Installer as shown in the figure below.

This actionwill bring 2 components as shown in the following figure.

Note: Don’t forget to add areference of CalculatorService and System.ServiceModel in your WindowsService.

Ok now let’scome back to the code and rename Service1.cs to something meaningful; umm likeCalculatorService.cs. Now open up the code editor of CalculatorService.cs bydouble clicking and paste the following code in your CalculatorService class.

public partial class CalculatorService : ServiceBase

{

private ServiceHosthost;

public CalculatorService()

{

InitializeComponent();

}

protected overridevoid OnStart(string[]args)

{

try

{

if(host != null)

{

host.Close();

}

host = newServiceHost(typeof(Service.Calculator));

host.Open();

}

catch(Exception ex)

{

throwex;

}

protected overridevoid OnStop()

{

if(host != null)

{

host.Close();

host = null;

}

This codeis simply creating a service host for type calculator WCF service referenced inour project.

Before weinstall this windows services let’s do some tweaks to the installer files.

First ofdouble click on ProjectInsaller.cs file to open it in Design mode and thenclick on ServiceProcessInstaller1 component.

Press f4 tosee its properties if not shown by default. Change the Account property fromUser to LocalService.

Now Click onServiceInstaller1 and change the following properties.

ServiceNamefrom Service1 to CalculatorService or something meaningful.

StartTypefrom Manual to Automatic.

Display namefrom empty to Calculator Service or something meaningful.

Description: A robust calculator or whatever you want.

Till now,we havecreated a service and its host but we really didn’t write ABC of our service.Most importantly we didn’t make our service SSL secure. So let’s do it. Butbefore we jump into it, we are missing some important things, "certificates"!

Creating and Configuring Certificates

Since this tutorialis about hosting a SSL service as windows service, we probably need server andclient certificates signed by a trusted certificate authority like VeriSign or Thwart. To get certificates from these authoritiesfor development or learning purpose is not only costly but time consuming tooand is not recommended.

How to make client and servercertificate by using MakeCert .exe command.

http://msdn.microsoft.com/en-us/library/ff648498.aspx

http://www.digitallycreated.net/Blog/38/using-makecert-to-create-certificates-for-development

If you wantto reinvent the wheel you can go to these link and create your own CA, Serverand client certificates. Otherwise you can use one of mine provided with thissolution to save your time.

If you areusing the certficiates which are provided with this solution, be sure to importclient and server certificates to Personal Folder. If you don’t know how to doit read below for step by step instructions.
How to import certificates to appropriate folders

Log on to the system as an administrator.
Click Start, click Run, type mmc, and then click OK.
On the File menu, click Add/Remove Snap-in, and then click Add.
Under Snap-in, double-click Certificates, click Computer account, and then click Next.
To manage certificates for the local computer, click Local computer, and then click Finish. .
Click Close.

Certificates(Computer Name) appears on thelist of selected snap-ins for the new console.

If you have no more snap-ins to add to the console, click OK.
To save this console, on the File menu, click Save.
Click on(+) sign to expand the Certifcates tree.
Right click on Personal Folder and follow the steps to import Server.cer and Client.cer Certificates.
Right click on Trusted Root Certification Authorities to import Our Certificate Authority.cer

Note: Thepassword for the certificate’s private key for both client and server is 1234

Alright, nowwe have created and imported these 3 certificates. Be sure that client andserver certificates should have private key with them as shown in the followingfigure.

Right clickon WindowsService Project and click on Add à New Item. Let’s add App.config.

Alright, I amgoing to configure my service based on config file as compared to write code.But you are free to choose whichever way you want to.

Since theintent of this tutorial is to teach how to host a SSL WCF service as a windowsService and not to teach how to create a windows service, I am skipping the ABCof WCF. You are free to write your ABC or copy one from the below.

<system.serviceModel>

<authentication certificateValidationMode="ChainTrust" revocationMode="NoCheck"

trustedStoreLocation="LocalMachine" />

clientCertificate>

<serviceCertificate findValue="24d7ac65704bc0a161cc2539d22ad2916f5cf4b0"

storeLocation="LocalMachine" storeName="My" x509FindType="FindByThumbprint" />

serviceCredentials>

behavior>

serviceBehaviors>

behaviors>

<host>

baseAddresses>

host>

<endpoint address=""

binding="wsHttpBinding" bindingConfiguration="SecureBinding"

contract="Service.Calculator" />

service>

services>

<binding name="SecureBinding" closeTimeout="00:010:00"

openTimeout="00:010:00" receiveTimeout="00:10:00" sendTimeout="00:010:00"

bypassProxyOnLocal="false" transactionFlow="false" hostNameComparisonMode="StrongWildcard"

maxBufferPoolSize="524288" maxReceivedMessageSize="65536" messageEncoding="Text"

textEncoding="utf-8" useDefaultWebProxy="true" allowCookies="false">

<readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"

maxBytesPerRead="4096" maxNameTableCharCount="16384" />

<reliableSession ordered="true" inactivityTimeout="00:10:00"

enabled="false" />

<transport clientCredentialType="Certificate" proxyCredentialType="None"

realm="" />

security>

binding>

wsHttpBinding>

bindings>

system.serviceModel>

configuration>

Let’s walkthrough couple of snippets in this configuration.

Services Element:

This aboveconfig snippet will create a WCF service “Service.Calculator”whose address is http://localhost:8022/CalculatorService. It means that service only exposes a singleendpoint on SSL available at https://localhost:8022/CalculatorService. Although you can expose anotherendpoint which is unsecure for internal connection like TCP. The services uses wsHttpBinding and which uses SecureBinding as a configuration (willbe discussed below).

The servicealso exposes another endpoint called mexat the address which exposes metadata i.e. WSDL.

There isanother property called contract which is in this tutorial is a class and notan interface. Please remember that this is not a WCF design session ortutorial, that’s why I have skipped many of industry standards orrecommendations here.

Bindings Element:

You guysprobably are familiar with bindings so I am not going to discuss it in depthexcept the security element of this.

This is the elementthat defines whether the web service is secure or not, if it is secured thenwhich mode it is; Transport layer security (TLS/SSL) or Message Based Security(MBS). We are using TLS with Certificates and no other, username, windows etc.

Until now wehaven’t actually made our service secure. We need to provide a servicecertificate. Which server will present to client to prove its identity at thetime of security handshake. Let’s jump on that section.

Behaviors Element:

Okay, so thissection defines the behavior of the service. How should the service behave?

First let’sdiscuss the following elements inside behavior tag.

ServiceCertificate Element:

This tells WCF that go find the certificate from My store of LocalMachine location. The finding method is finding it bycertificate thumbprint whose value is 24d7ac65704bc0a161cc2539d22ad2916f5cf4b0.

This sentence will be translated by windows as go find thecertificate in Personal Folder of Computer Account location whosethumbprint value matches 24d7ac65704bc0a161cc2539d22ad2916f5cf4b0

How to get certificate thumbprint:

Now for thosepeople who don’t know how to get thumbprint I can show you by taking extrapain.
Double click on your Our Servercertificate in the personalà Certificates Folder. Click on 2^ndtab Details and scroll all the way down, youwill see thumbprint as shown the figure below.

I could have search the certficate by other means, subject name,expiration date, issuer etc but I prefer thumbprint as this is unique for eachcertficiate.

Note: Did you see that I have pasted thumprint without spaces? Veryimportant.

ClientCertificateElement:

Client Certificate Element:

Now what doesthis script telling us? This is merely saying 3 things. When client tries toconnect service, it will present WCF service a certificate. WCF service has to trustthe certificate chain which is present in its LocalMachine location in windows certificate store. Also you don’t need to checkonline whether the certificate has been revoked or not at this stage.

If you haveimplemented PeerTrust instead of ChainTrust, the scenario will bedifferent. In that case you must have installed client’s public key certificatealong with its chain of issuers in your server certificate stores inappropriate folder. Similarly, the client have to install server public keycertificate along with its trust chain in client’s computer‘s certificatestores in appropriate folders. Also in this case, the config file will slightlychange and you have write configuration tofind client certificate. Same code have to be written in client’s config tofind the server public cert.

Installing the Service

Installation using installutil.exe:

Let’s installour service now and see if it is working or not. You can create a setup projectto install or use the following method which I am using to install thisservice. This is quick way to install and debug the issues as compared to setupproject.

Installutil.exeis use to install and uninstall windows service that serves an efficient toolin development.

http://msdn.microsoft.com/en-us/library/sd8zc8ha%28v=vs.80%29.aspx

Go to theVisual Stuido 2010 command prompt and type the following command to install theWindowsService.

Oppose to theabove command you can use installutil /u [exe path] to uninstall the service.

Alright,after installing the service go to the Services component under Control Panel--> Administrative tools-->Services or you can type services.msccommand in the run dialog box to open this quickly.

Starting the service:

See ourcalculator service is installed and ready for running. Click on Start to runthe service.

Go tointernet explorer and type the following address in the browser.

https://localhost:8022/CalculatorService

Hmmm... Whywe aren’t getting the WSDL? Yes we have enable https metadata in server config.Also we have provided the correct certificate chains, thumbprint, behavior anddouble check everything else. What is the problem now?

Configuring HTTPS WCF Service with Httpcfg.exeutility

This is heartof this tutorial. We forgot to configure the port (8022) with a X.509certificate. Why? Here is an explanation from MSFT.

http://msdn.microsoft.com/en-us/library/ms733768.aspx

Ok, now thatyou have understood the necessity of this command line tool. Let’s start tobind our certificate to the port.

Pleasedownload httpcfg.exe from http://www.microsoft.com/download/en/details.aspx?id=18546

For windowsXP, For Vista and Windows server 2008 you would have get netsh.exe which is outof scope of this tutorial.

Note: Ifin future the download location of httpcfg.exe changes, you can always get itfrom the solution zip file I am providing you.

Okay, nowlet’s open up windows command prompt and go to the directory where httpcfg.exeexists. In this case it is in c:\blog\httpcfg.exe.

Type thefollowing command to see how many ports are bound to X509 certificate and theone you are using is not in there.

C:\Blog> httpcfg query ssl

In mycomputer only 1 port 8021 is bound to some X509 certificate whose hash (Thumbprint)is not the one which our certificate has. So no problem

Let’s configure 8022 port to the server certificate whosethumbprint is 24d7ac65704bc0a161cc2539d22ad2916f5cf4b0

The commandfor binding the port to Cert is

C:\Blog\WCF> httpcfg set ssl -i0.0.0.0:8022 –h 24d7ac65704bc0a161cc2539d22ad2916f5cf4b0–f 2

If you receivethe following message it means you are successful.

HttpSetServiceConfiguration completedwith 0.

Let’s queryagain to see how many ports are bound to which certs and if 8022 is one of themor not.

Do you seethat? We have configured port 8022 with the Server certificate whose thumbprintis same we are using in our server app.config.

Good deal.Try browsing the URL again.

https://localhost:8022/CalculatorService

Click on ViewCertificate button. Yes it is the server certificate that we have provided toWCF.

Click on Okbutton followed by Yes button tocontinue. You will probably see this page, but don’t worry about it as ourserver certificate is not issued to this machine name. Click on continue to this website (not recommended) link.

Aha! Here wesee our secured https WCF service hosted as windows services exposing itsmetadata in a WSDL.

Here is theWSDL screen shot.

Good deal,isn’t it?

Creating WCF Client:

Ok now thatservice is running we want our clients to connect to it. Let’s make a simpleconsole application client which will call this service to achieve the goal.

Right clickon solution file-->Add-->New Project and select Console Application. Rename the projectas Client and press ok.

Next step isto add a service reference. Right click on Client project and click on Add Service Reference.

Type thefollowing address to add a service reference and click on Go button.

https://localhost:8022/CalculatorService

Note: Ifyou receive an error warning from Visual Studio that says “Visual Studio hasdetected a problem with site’s security certificate”, please ignore it by clickyes.

Click okbutton add this as a service reference.

Note: Did yousee Visual Studio automatically creates app.config file with a bunch of configelements in it? This is the magic of VS that is only available to .Net developers.

Double clickon Program.cs file in Client Project to write the following code snippet.

CalculatorService.CalculatorClient proxy = newCalculatorService.CalculatorClient();

Console.WriteLine("The Result of Addition is:" +proxy.Add(2, 2));

Console.ReadLine();

Okay folks itis time to hit F5 (if client is your startup project).

Did you getthe following picture too? If not then you are doing something wrong.

Well ofcourse it was expected, how does VS know which certificate you want to provide?

Yes, weforgot to write configuration to provide client certificate. Remember wealready created and imported a client certificate into our personal folder?

Again, thereare 2 ways to achieve this goal, via coding and via configuration. I opt in forconfiguration.

Let’s add thefollowing configuration snippet in your app.config in Client Project.

serviceCertificate>

<clientCertificate

findValue="5491c10dcf012c91008a6b2857b3bd2c13ab9791"

storeLocation="LocalMachine" storeName ="My" x509FindType="FindByThumbprint" />

clientCredentials>

behavior>

endpointBehaviors>

behaviors>

Don’t forgetto add this behavior name “SecureEpBehavior” in behaviorConfiguration elementin tag as highlighted below.

<endpoint address="https://localhost:8022/CalculatorService/CS"

binding="wsHttpBinding" bindingConfiguration="WSHttpBinding_Calculator" behaviorConfiguration="SecureEpBehavior"

contract="CalculatorService.Calculator" name="WSHttpBinding_Calculator" />

client>

The fullconfig file will be shown as below.

xml version="1.0" encoding="utf-8" ?>

<system.serviceModel>

serviceCertificate>

<clientCertificate findValue="5491c10dcf012c91008a6b2857b3bd2c13ab9791"

storeLocation="LocalMachine" storeName ="My" x509FindType="FindByThumbprint" />

clientCredentials>

behavior>

endpointBehaviors>

behaviors>

<binding name="WSHttpBinding_Calculator" closeTimeout="00:01:00"

openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"

bypassProxyOnLocal="false" transactionFlow="false" hostNameComparisonMode="StrongWildcard"

maxBufferPoolSize="524288" maxReceivedMessageSize="65536"

messageEncoding="Text" textEncoding="utf-8" useDefaultWebProxy="true"

allowCookies="false">

<readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"

maxBytesPerRead="4096" maxNameTableCharCount="16384" />

<reliableSession ordered="true" inactivityTimeout="00:10:00"

enabled="false" />

<transport clientCredentialType="Certificate" proxyCredentialType="None"

realm="" />

security>

binding>

wsHttpBinding>

bindings>

<endpoint address="https://localhost:8022/CalculatorService"

binding="wsHttpBinding" bindingConfiguration="WSHttpBinding_Calculator" behaviorConfiguration="SecureEpBehavior"

contract="CalculatorService.Calculator" name="WSHttpBinding_Calculator" />

client>

system.serviceModel>

configuration>

Let’s try onemore time by press F5. This time we should see a message that we have neverseen as shown below.

Now what? Ifyou click on View Details… under Actions: Go to InnerException and go to InnerException of this InnerExcepiton.You will see a message that says “Theremote certificate is invalid according to the validation procedures” asshown in the following picture.

You probablywill be wondering something is wrong with our server certificate or chain trustor method of validation and the doubt goes on and on until you get frustratedwhy on earth this message is coming. Well there is nothing wrong with ourcertificate except a minor problem with Certificate name that was not issued tothis machine or you can say that doesn’t resemble to this machine name.

And thatmakes completely sense, since you are in development mode and the server orclient certificate that you got is for production computer, if otherwise youget certificate of each environment. So how do we resolve this? Well there is aconfiguration that you need to put on top of your client configuration file sothat WCF doesn’t check for the certificate name anymore. Here is thatconfiguration snippet.

<system.net>

settings>

system.net>

So ourcomplete updated client app.config will look like below.

xml version="1.0" encoding="utf-8" ?>

<system.net>

settings>

system.net>

<system.serviceModel>

serviceCertificate>

<clientCertificate findValue="5491c10dcf012c91008a6b2857b3bd2c13ab9791"

storeLocation="LocalMachine" storeName ="My" x509FindType="FindByThumbprint" />

clientCredentials>

behavior>

endpointBehaviors>

behaviors>

<binding name="WSHttpBinding_Calculator" closeTimeout="00:01:00"

openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"

bypassProxyOnLocal="false" transactionFlow="false" hostNameComparisonMode="StrongWildcard"

maxBufferPoolSize="524288" maxReceivedMessageSize="65536"

messageEncoding="Text" textEncoding="utf-8" useDefaultWebProxy="true"

allowCookies="false">

<readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"

maxBytesPerRead="4096" maxNameTableCharCount="16384" />

<reliableSession ordered="true" inactivityTimeout="00:10:00"

enabled="false" />

<transport clientCredentialType="Certificate" proxyCredentialType="None"

realm="" />

security>

binding>

wsHttpBinding>

bindings>

<endpoint address="https://localhost:8022/CalculatorService"

binding="wsHttpBinding" bindingConfiguration="WSHttpBinding_Calculator" behaviorConfiguration="SecureEpBehavior"

contract="CalculatorService.Calculator" name="WSHttpBinding_Calculator" />

client>

system.serviceModel>

configuration>

Try pressingF5 now. I am positive you will the screen below if you have followed thetutorial thoroughly and didn’t miss or skip any step.

Happy ending :)
Source Code