Skip to main content

Windows Live - Web Authentication

Windows LIVE series:
Live ID se poate folosii pentru doua lucruri:
  • autentificarea userilor in aplicatia noastra folosind contul de Live ID
  • accesul aplicatiei noastre la servicii pe care un user de LIVE ID are access( photo sharing, agenda, calendar, etc)
Astazi o sa discutam despre cum poate un utilizator sa se autentifice in aplicatia noastra folosind contul de de Live ID.
Mai jos o sa prezint vechiul mod de autentificare, care a devenit absolute, odata cu lansarea "Live Connect", despre care o sa povestim cat de curand. Prefer sa prezint si acest mecanism in cazul in care lucrati cu aplicatii deja facute care folosesc vechiul mecanism de autentificare.
Acest mecanism de autentificare a fost denumit de cei de la Microsoft "Windows Live ID Web Authetification", dar nu are nimic mai special. In momentul in care userul doreste sa se autentifice, acesta este redirectat spre pagina Windows Live ID, unde isi va introduce datele. Dupa acest pas, userul este redirectat inapoi spre aplicatia noastra cu o cheie unica( token) - denumita Cliend ID, pe baza careia putem sa identificam userul. Pe langa aceste informatii, avem access la cateva date de baza a userului precum nume, tara, etc.
Cliend ID este o cheie unica formata din 16 caractere, pe care o sa trasmiteti la servere Windows Live de fiecare data cand un user se autentifica. Toate datele care se trasmit o sa fie encriptate si semntate pe baza unuei chei secrete pe care o primiti in momentul in care va inregistrati aplicatia.
Primul pas pe care trebuie sa il facem este sa ne inregistram aplicatia. Fiecare aplicatie se identifica unic pe baza unei chei. Acest lucru se poate face la urmatorul link:
Odata ce avem aplicatia inregistrata, trebuie sa adaugam in aplicatia noastra un link de autentificare prin Live ID. Acest link o sa contina ca si parametrii:
  • appid - cliend ID( cheia unica a aplicatiei noastre)
  • context -( optional) pagina spre care userul sa fie redirectionat dupa ce autentificarea se finalizeaza( ex. welcome.html)
  • style -( optional) o colectie de atribute folosite prin care se poate personaliza bunoul de sign in
Dupa ce userul isi introduce credentiale o sa fie redirectionat spre pagina noastra. Pe flowul normal, in cookies o sa gasim un token encriptat cu cheia "webauthtoken". Acesta o sa contina urmatoarele date despre user:
  • User.Id – id-ul unic a fiecarui user
  • User.Timestamp – data ultimei autentificari
  • User.Context – contextul care a fost specificat in momentul autentificarii
  • User.Token – token-ul unic a userului curent( dupa o anumita perioada de timp acesta o sa expire)
Trebuie precizat ca datele sunt encriptate este AES128, iar cel de semnare este HMAC-SHA256. Mai jos gasiti un exemplu de cum trebuie facuta decriptatea si extragerea datelor.
public string DecryptResponse(){     const int ivLength = 16;     token = HttpUtility.UrlDecode(token);     byte[] ivAndEncryptedValue = Convert.FromBase64String(token);     var decryptAlg = new RijndaelManaged();     decryptAlg.KeySize = 128;     decryptAlg.Key = cryptKey;     decryptAlg.Padding = PaddingMode.PKCS7;     var memStream = new MemoryStream(ivAndEncryptedValue);     byte[] iv = new byte[ivLength];     memStream.Read(iv, 0, ivLength);     decryptAlg.IV = iv;     cStream = new CryptoStream(memStream, decryptAlg.CreateDecryptor(),                          CryptoStreamMode.Read);     sReader = new StreamReader(cStream, Encoding.ASCII);     return sReader.ReadToEnd();}

In urmatorul post o sa discutam despre Live Connect.


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 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 …

Fundamental Books of a Software Engineer (version 2018)

More then six years ago I wrote a blog post about fundamental books that any software engineer (developer) should read. Now it is an excellent time to update this list with new entries.

There are 5 different categories of books, that represent the recommended path. For example, you start with Coding books, after that, you read books about Programming, Design and so on.
There are some books about C++ that I recommend not because you shall know C++, only because the concepts that you can learn from it.


Writing solid codeCode completeProgramming Pearls, more programming pearls(recommended)[NEW] Introduction to Algorithms


Refactoring (M. Fowler)Pragmatic ProgrammerClean code[NEW] Software Engineering: A Practitioner's Approach[NEW] The Mythical Man-Month[NEW] The Art of Computer Programming


Applying UML and Patterns (GRASP patterns)C++ coding standards (Sutter, Alexandrescu)The C++ programming language (Stroustrup, Part IV)Object-oriented programming (Peter Coad)P…