Skip to main content

Running WIF Relying parties in Windows Azure

I am coping this blog from another blog here. Copying it here just to make sure I can find it in the future. My Azure app had this issue and this fixed the problem. 

When running in a multi server environment like windows azure it is required to make sure the cookies generated by WIF are encrypted with the same pair of keys so all servers can open them.

Encrypt cookies using RSA

In Windows Azure, the default cookie encryption mechanism (which uses DPAPI) is not appropriate because each instance has a different key. This would mean that a cookie created by one web role instance would not be readable by another web role instance. This could lead to service failures effectively causing denial of the service. To solve this problem you should use a cookie encryption mechanism that uses a key shared by all the web role instances. The following code written to global.asax shows how to replace the default SessionSecurityHandler object and configure it to use the RsaEncryptionCookieTransform class:

next upload the certificate to the hosted service and declare it in the LocalMachine certificate store of the running role.

void Application_Start(object sender, EventArgs e)
{
    FederatedAuthentication.ServiceConfigurationCreated += OnServiceConfigurationCreated;
}
 
private void OnServiceConfigurationCreated(object sender, ServiceConfigurationCreatedEventArgs e)
{
   List<CookieTransform> sessionTransforms =
       new List<CookieTransform>(new CookieTransform[] 
       {
          new DeflateCookieTransform(), 
          new RsaEncryptionCookieTransform(e.ServiceConfiguration.ServiceCertificate),
          new RsaSignatureCookieTransform(e.ServiceConfiguration.ServiceCertificate)
       });
 
       SessionSecurityTokenHandler sessionHandler =
         new SessionSecurityTokenHandler(sessionTransforms.AsReadOnly());
            e.ServiceConfiguration.SecurityTokenHandlers.AddOrReplace(sessionHandler);
}

 

image

image

Failing to do the above will generate the following exception when running a relying party in azure: "InvalidOperationException: ID1073: A CryptographicException occurred when attempting to decrypt the cookie using the ProtectedData API". It means that decryption with DPAPI failed. It makes sense because DPAPI key is coupled with the physical machine it is running on.

After changing the encryption policy (like so) make sure to delete all existing cookies other wise you will get the following exception: CryptographicException: ID1014: The signature is not valid. The data may have been tampered with. (It means that an old DPAPI cookie is being processed by the new RSA policy and that will obviously will fail.

Comments

Popular posts from this blog

Uniting Testing Expression Predicate with Moq

I recently was setting up a repository in a project with an interface on all repositories that took a predicate. As part of this I needed to mock out this call so I could unit test my code. The vast majority of samples out there for mocking an expression predicate just is It.IsAny<> which is not very helpful as it does not test anything other then verify it got a predicate. What if you actually want to test that you got a certain predicate though? It is actually pretty easy to do but not very straight forward. Here is what you do for the It.IsAny<> approach in case someone is looking for that. this .bindingRepository.Setup(c => c.Get(It.IsAny<Expression<Func<UserBinding, bool >>>())) .Returns( new List<UserBinding>() { defaultBinding }.AsQueryable()); This example just says to always return a collection of UserBindings that contain “defaultBinding” (which is an object I setup previously). Here is what it looks like when you want to pass in an exp

Anatomy of Sitecore Business Rule - Macros

In previous posts, we talked about  field syntax and the basic structure of business rules . This time we are going to dive into macros in the business rules. Macros are used as part of the business rule syntax. The syntax looks like this and calls for 4 parameters. [Property to set, Operator/Macro, AdditionalParameters, Display text]. When I first started working with business rules the difference between operator and macro was confusing. To add to this confusion some of the out-of-the-box macros are named with the term "operator" (like ListOperator who's configuration points to a class called ListMacro and the class implements IRuleMacro). Anything under the path /sitecore/system/Settings/Rules/Definitions/Macros should be a macro and should implement IRuleMacro. Macros have the follow characteristics: They inherit the IRuleMacro interface The interface requires this execute method void Execute(XElement element, string name, UrlString parameters, string value)

Experience Profile Anonymous, Unknown and Known contacts

When you first get started with Sitecore's experience profile the reporting for contacts can cause a little confusion. There are 3 terms that are thrown around, 1) Anonymous 2) Unknown 3) Known. When you read the docs they can bleed into each other a little. First, have a read through the Sitecore tracking documentation to get a feel for what Sitecore is trying to do. There are a couple key things here to first understand: Unless you call " IdentifyAs() " for request the contact is always anonymous.  Tracking of anonymous contacts is off by default.  Even if you call "IdentifyAs()" if you don't set facet values for the contact (like first name and email) the contact will still show up in your experience profile as "unknown" (because it has no facet data to display).  Enabled Anonymous contacts Notice in the picture I have two contacts marked in a red box. Those are my "known" contacts that I called "IdentifyAs"

Excel XIRR and C#

I have spend that last couple days trying to figure out how to run and Excel XIRR function in a C# application. This process has been more painful that I thought it would have been when started. To save others (or myself the pain in the future if I have to do it again) I thought I would right a post about this (as post about XIRR in C# have been hard to come by). Lets start with the easy part first. In order to make this call you need to use the Microsoft.Office.Interop.Excel dll. When you use this dll take note of what version of the dll you are using. If you are using a version less then 12 (at the time of this writing 12 was the highest version) you will not have an XIRR function call. This does not mean you cannot still do XIRR though. As of version 12 (a.k.a Office 2007) the XIRR function is a built in function to Excel. Prior version need an add-in to use this function. Even if you have version 12 of the interop though it does not mean you will be able to use the function. The

Windows Workflow Unit Testing

I know people have very mixed opinions about Windows Workflow and, to be honest, so do I. Really I am not even sure if it has much of a future given the little attention Microsoft has given it. However, despite all that and rather your like it or not there are times when you may use it and want to unit test it. The question is how? Well there are not a lot of options but there is one, that for me, has proven valuable. People tend to use Windows Workflow in a few different ways, so first let me explain how I have use it most. I have never really used it where I programmatically created and instantiate of my own workflow. For me it has pretty much all been using the Windows Workflow designer and using IIS as my workflow host. Then inside those XAML workflows I have custom activities I create and need to test. Do to this I have found one tool that does this pretty well and pretty easy. Microsoft Activities Unit Testing It is an old framework but it still gets the job done. There is