Skip to main content

Manage bearer token when we scale on more than one server - OWIN, Katana, AngularJS

By
In this post we will talk about bearer token authentication and how we should manage this token when our application is running on more than one server -  when we are using OWIN, Katana and AngularJS.

Token Characteristics
First of all let’s see what are the characteristics of bearer token:
  • Generate by server
  • Contains user claims (what kind of operations a user can do/roles)
  • All information that a token contains are encrypted
  • Token information can be decrypted only by the machine that created the token
  • Expiration date is encrypted in the token itself
  • No token information are stored on the server side
  • Encryption is safe enough to be used worldwide (Facebook, Google and Twitter are using it) 
  • A token can be used by external system only when decryption key is shared
  • Easy and cheap to generate tokens
Why?
All this sounds good, but what is happening if we want to go in production. In this case we should be able to scale our backend from one node to 3 or 10 nodes.
Do we need stick connection?... to be able to redirect all the request from the same client to the same instance (because token can be decrypted only by the machine that generate the key)
NO, we don’t need this.

How?
To be able to allow other instances or servers to decrypt and access token information we need to set the machine key. This can be configured directly in the web.config. Once this configuration is done all the encryption/decryption by that application will be use them.

In the system.web section of our configuration file we need to specify the machine key node. We need to specify the validation key, decryption key and what kind of validation and decryption mechanism we want to use.
  <system.web>
    <compilation debug="true" targetFramework="4.5" />
    <httpRuntime targetFramework="4.5" />
    <machineKey validationKey="BDE5239FBD71982481D87D815FA0A65B9F5982D99DFA96E6D92B782E0952D58818B479B19FF6D95263E85B0209297E6858B57D1E0BD3EFECE5E35742D605F2A7"
              decryptionKey="8E8496D7342EA258526CF6177E04EA7D208E359C95E60CD2A462FC062B9E41B3"
              validation="SHA1"
              decryption="AES"/>
  </system.web>
Be aware, don’t use this keys, you should generate your own keys, otherwise "I" will be able to decrypt your token also.
For ISS, the machine key and validation key can be generated easily using ISS features (https://technet.microsoft.com/en-us/library/cc755177(v=ws.10).aspx) or we can use PowerShell (http://support.microsoft.com/kb/2915218#AppendixA)

Conclusion
In conclusion we saw that it is not complicated to 'connect’ multiple application instances to use and access the same token but we need to be able to share the machine key between them.
Another option is to have a dedicate machine that manage and validate token, but this is another story.
Labels:

Comments

Post a Comment

Popular posts from this blog

Windows Docker Containers can make WIN32 API calls, use COM and ASP.NET WebForms

By
After the last post , I received two interesting questions related to Docker and Windows. People were interested if we do Win32 API calls from a Docker container and if there is support for COM. WIN32 Support To test calls to WIN32 API, let’s try to populate SYSTEM_INFO class. [StructLayout(LayoutKind.Sequential)] public struct SYSTEM_INFO { public uint dwOemId; public uint dwPageSize; public uint lpMinimumApplicationAddress; public uint lpMaximumApplicationAddress; public uint dwActiveProcessorMask; public uint dwNumberOfProcessors; public uint dwProcessorType; public uint dwAllocationGranularity; public uint dwProcessorLevel; public uint dwProcessorRevision; } ... [DllImport("kernel32")] static extern void GetSystemInfo(ref SYSTEM_INFO pSI); ... SYSTEM_INFO pSI = new SYSTEM_INFO(...
Post a Comment
Read more

How to audit an Azure Cosmos DB

By
In this post, we will talk about how we can audit an Azure Cosmos DB database. Before jumping into the problem let us define the business requirement: As an Administrator I want to be able to audit all changes that were done to specific collection inside my Azure Cosmos DB. The requirement is simple, but can be a little tricky to implement fully. First of all when you are using Azure Cosmos DB or any other storage solution there are 99% odds that you’ll have more than one system that writes data to it. This means that you have or not have control on the systems that are doing any create/update/delete operations. Solution 1: Diagnostic Logs Cosmos DB allows us activate diagnostics logs and stream the output a storage account for achieving to other systems like Event Hub or Log Analytics. This would allow us to have information related to who, when, what, response code and how the access operation to our Cosmos DB was done. Beside this there is a field that specifies what was th...
Post a Comment
Read more

Cloud Myths: Cloud is Cheaper (Pill 1 of 5 / Cloud Pills)

By
Cloud Myths: Cloud is Cheaper (Pill 1 of 5 / Cloud Pills) The idea that moving to the cloud reduces the costs is a common misconception. The cloud infrastructure provides flexibility, scalability, and better CAPEX, but it does not guarantee lower costs without proper optimisation and management of the cloud services and infrastructure. Idle and unused resources, overprovisioning, oversize databases, and unnecessary data transfer can increase running costs. The regional pricing mode, multi-cloud complexity, and cost variety add extra complexity to the cost function. Cloud adoption without a cost governance strategy can result in unexpected expenses. Improper usage, combined with a pay-as-you-go model, can result in a nightmare for business stakeholders who cannot track and manage the monthly costs. Cloud-native services such as AI services, managed databases, and analytics platforms are powerful, provide out-of-the-shelve capabilities, and increase business agility and innovation. H...
Post a Comment
Read more