The purpose of this report is to document the project that I was working on during openlab summer student program in IT-DB-IMS section. In the first chapter of this paper you can find introduction into the project. In this part I have explained what is Single Sign-On and how it works as well as listed all the use cases for authorization protocols at CERN. In the next chapter you will find project overview with the explanation of two protocols and comparison of them. SAML2 is an authorization protocol widely used at CERN and OAuth2 is the subject of the project. In system analysis chapter, all the scenarios for OAuth2 protocol have been presented. In the next section you will find three different approaches that I have implemented to test OAuth2 protocol. Last two parts of the report are conclusions and future work.