Using client certificates in .NET part 2: creating self signed client certificates

January 14, 2016 Leave a comment

Introduction

In the previous post we went through a short introduction on client side certificates. We said that client certificates are used by web clients to strongly authenticate themselves. Client certificates can provide an extra step in the authentication process to tighten security.

In this post we’ll see how to create self-signed client certificates for testing using a tool called makecert.exe.

The process of creating client certificates on your local machine is almost identical to how we generated server side certificates in the series in this series.

Read more of this post

Filed under .NET, Security Tagged with , , , , ,

Converting a string into a DateTime with an exact date format in C# .NET

January 13, 2016 2 Comments

How do you read the date “03-10-2014”? For some of you this will be October 03 2014. For others, especially those from the US this will be interpreted as March 10 2014. This is because dates are represented in different formats in different cultures.

Consider the following code:

string dateString = "03-10-2014";
DateTime parsedDate = DateTime.Parse(dateString);
string toString = parsedDate.ToLongDateString();

Read more of this post

Filed under .NET, C# language features Tagged with , ,

Getting notified when collection changes with ObservableCollection in C# .NET

January 12, 2016 1 Comment

Imagine that you’d like to be notified when something is changed in a collection, e.g. an item is added or removed. One possible solution is to use the built-in .NET generic collection type ObservableCollection of T which is located in the System.Collections.ObjectModel namespace. The ObservableCollection object has an event called CollectionChanged. You can hook up an event handler to be notified of the changes.

If you don’t know what events, event handlers and delegates mean then start here.

Let’s see a simple example with a collection of strings:

Read more of this post

Filed under .NET, C# language features, Generics Tagged with ,

Using client certificates in .NET part 1: introduction

January 11, 2016 1 Comment

Introduction

Digital certificates play a crucial role in web security. If you work as a web developer then you’ve probably come across at least some security related project where you had to deal with certificates in code.

Certificates come in a couple of different versions depending on their function, the most pervasive of which probably being server side ones for SSL connections. We’ve gone through server side certificates in some detail before on this blog starting here. In this series we’ll concentrate on client certificates and see what role they can play in web security. Most of the material on server side certificates, especially the first 2 posts are also relevant for this discussion.

It’s important to note already now that you can combine a number of security levels and solutions in your projects:

  • You can have the traditional forms based authentication. You can read about it on this blog here and here.
  • Custom authentication. Here‘s a series dedicated to custom auth in Web API 2 as an OWIN/Katana component
  • Server-side certificates, see the reference above
  • Client-side certificates, to be discussed in this series
  • Various techniques related to cryptography, such as asymmetric encryption. You can check out the section called “Security and cryptography” on this page for inspiration.

…and there are probably many more options not listed here. The point is that these techniques can be combined, you are not restricted to just using one of them.

Read more of this post

Filed under .NET, Security Tagged with , , , , ,

Domain Driven Design with Web API extensions part 16: testing the MongoDb repository in the DDD application

January 7, 2016 Leave a comment

Introduction

In the previous post we implemented the ITimetableViewModelRepository interface in the WebSuiteDemo.Loadtesting.Repository.MongoDb project. We saw that the implementation was practically the same as in the EF repository layer. The only difference was due to details in the MongoDb query syntax.

In this post we’ll finish off this extension series to the load testing DDD demo project. We’ll wire up the MongoDb repository layer with the rest of the application.

Read more of this post

Filed under .NET, Design principles, MongoDb Tagged with , , ,

Domain Driven Design with Web API extensions part 15: implementing the ITimetableViewModelRepository interface in MongoDb

January 4, 2016 Leave a comment

Introduction

In the previous post we implemented the ITimetableRepository interface in the MongoDb repository layer. We saw that the code carried out the same type of logic as its EF counterpart. Most of the new things were related to MongoDb query syntax.

In this post we’ll implement the ITimetableViewModelRepository interface. Make sure you have the DDD demo project open.

Read more of this post

Filed under .NET, Design principles, MongoDb Tagged with , , ,

Domain Driven Design with Web API extensions part 14: implementing the ITimetableRepository interface in MongoDb

December 24, 2015 Leave a comment

Introduction

In the previous post we looked at a couple of basic operations with the MongoDb .NET driver. I decided to include that “intermediate” post so that you won’t get overwhelmed with a lot of new code if you’re new to MongoDb.

In this post we’ll to be implement the ITimetableRepository interface in the MongoDb repository layer.

Read more of this post

Filed under .NET, Design principles, MongoDb Tagged with , , ,

4 ways to enumerate processes on Windows with C# .NET

December 23, 2015 Leave a comment

A Process object in the System.Diagnostics namespace refers to an operating-system process. This object is the entry point into enumerating the processes currently running on the OS.

This is how you can find the currently active process:

Process current = Process.GetCurrentProcess();
Console.WriteLine(current);

…which will yield the name of the process running this short test code.

It’s probably very rare that you’ll use the above method for anything as it’s not too useful.

Read more of this post

Filed under .NET, Diagnostics Tagged with , ,

5 ways to write to a file with C# .NET

December 22, 2015 Leave a comment

It’s a common scenario that you need to write some content to a file. Here you see 5 ways to achieve that.

1. Using a FileStream:

private void WriteToAFileWithFileStream()
{
	using (FileStream target = File.Create(@"c:\mydirectory\target.txt"))
	{
		using (StreamWriter writer = new StreamWriter(target))
		{
			writer.WriteLine("Hello world");
		}
	}
}

Read more of this post

Filed under .NET, Files and directories Tagged with ,

Domain Driven Design with Web API extensions part 13: query examples with the MongoDb driver

December 21, 2015 1 Comment

Introduction

In the previous post we successfully seeded our MongoDb load testing data store. We saw that the Seed() method wasn’t all that different from its EntityFramework equivalent.

In this post we’ll look at a range of examples of using the MongoDb driver. We’ll primarily consider CRUD operations. Originally I wanted to simply present the implementation of the domain repository interfaces. However, I thought it may be too overwhelming for MongoDb novices to be presented all the new object types and query functions. The purpose of this “intermediate” post is therefore to provide a soft start in MongoDb queries.

We’ll be working in the MongoDbDatabaseTester project of the DDD demo solution in this post. Make sure you start up the MongoDb server with the “mongod” command in a command prompt.

Read more of this post

Filed under .NET, Design principles, MongoDb Tagged with , , ,

← Older posts

Newer posts →

Elliot Balynn's Blog

A directory of wonderful thoughts

Software Engineering

Web development

Disparate Opinions

Various tidbits

chsakell's Blog

WEB APPLICATION DEVELOPMENT TUTORIALS WITH OPEN-SOURCE PROJECTS

Once Upon a Camayoc

ARCHIVED: Bite-size insight on Cyber Security for the not too technical.