Skip to main content

How to get a certificate from a PKCS7 file

In the last period of time I was forced to play a lot with certificates from .NET code (in my case was C#). The good part when you are using .NET is that you have an API that can be used to manage system certificates.
It is pretty simple to load a certificate from certificates store, file or an array of bytes.
X509Certificate2 cert = 
    new X509Certificate2(bytes);
In the above example I am loading a certificate from an array of bytes. The code is pretty simple and works great.
There are situations when you receive a certificate from an external system. In this cases the first step that you need to do is to save the certificate local. When you are a 3rd party and you are receiving a certificate from a server you should be aware of the format of the certificate.
In my case I received a certificate signed in PKCS7 byte array without knowing this and I assumed that it is enough to load the certificate using the constructor. The funny thing is that you will be able to load a signed PKCS7 file using the certificate constructor without any kind of problems, but you will not load the certificate that you expect.
This is happening because PKCS7 signed filed can have more than one certificate and X509Certificate2 constructor will load the certificate that was used to signed the store rather than certificates that can be found in the rawData of PKCS7.
To be able to access and load a certificate from the rawData of PKCS7 file you will need to use SignedCms. This class give you the possibility to access a message in PKCS7 format. This is the best and simple way to access all the certificates from a signed file.
SignedCms cms = new SignedCms();
cms.Decode(bytes);
x509certificate2Collection certs = cms.Certificates;
The Certificates property is a X509CertificateCollection that contains all the certificates from the signed file.

Comments

Popular posts from this blog

How to check in AngularJS if a service was register or not

There are cases when you need to check in a service or a controller was register in AngularJS.
For example a valid use case is when you have the same implementation running on multiple application. In this case, you may want to intercept the HTTP provider and add a custom step there. This step don’t needs to run on all the application, only in the one where the service exist and register.
A solution for this case would be to have a flag in the configuration that specify this. In the core you would have an IF that would check the value of this flag.
Another solution is to check if a specific service was register in AngularJS or not. If the service was register that you would execute your own logic.
To check if a service was register or not in AngularJS container you need to call the ‘has’ method of ‘inhector’. It will return TRUE if the service was register.
if ($injector.has('httpInterceptorService')) { $httpProvider.interceptors.push('httpInterceptorService&#…

ADO.NET provider with invariant name 'System.Data.SqlClient' could not be loaded

Today blog post will be started with the following error when running DB tests on the CI machine:
threw exception: System.InvalidOperationException: The Entity Framework provider type 'System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer' registered in the application config file for the ADO.NET provider with invariant name 'System.Data.SqlClient' could not be loaded. Make sure that the assembly-qualified name is used and that the assembly is available to the running application. See http://go.microsoft.com/fwlink/?LinkId=260882 for more information. at System.Data.Entity.Infrastructure.DependencyResolution.ProviderServicesFactory.GetInstance(String providerTypeName, String providerInvariantName) This error happened only on the Continuous Integration machine. On the devs machines, everything has fine. The classic problem – on my machine it’s working. The CI has the following configuration:

TeamCity.NET 4.51EF 6.0.2VS2013
It seems that there …

Run native .NET application in Docker (.NET Framework 4.6.2)

Scope
The main scope of this post is to see how we can run a legacy application written in .NET Framework in Docker.

Context
First of all, let’s define what is a legacy application in our context. By a legacy application we understand an application that runs .NET Framework 3.5 or higher in a production environment where we don’t have any more the people or documentation that would help us to understand what is happening behind the scene.
In this scenarios, you might want to migrate the current solution from a standard environment to Docker. There are many advantages for such a migration, like:

Continuous DeploymentTestingIsolationSecurity at container levelVersioning ControlEnvironment Standardization
Until now, we didn’t had the possibility to run a .NET application in Docker. With .NET Core, there was support for .NET Core in Docker, but migration from a full .NET framework to .NET Core can be costly and even impossible. Not only because of lack of features, but also because once you…