Our investigation focuses on Microsoft proprietary protocols with the help of a network trace and references. The steps that will be covered are specific to authentication view (MS-Chapv2), key derivation for encryption and the algorithm of the compression feature (MPPE/MPPC). Finally, to complete our approach, we will illustrate weaknesses through a new forensic tool dedicated to these protocols.
Details on MSChap-v2 : The first chapter aims to understand how the authentication protocol works ; Overview of MPPE protocol : We explain briefly the encryption protocol ; Overview of MPPC protocol : Here, we take a look at the compression feature ; Decipher MPPE by breaking MSCHAP-v2 : We decipher MPPE protocol with the help of MSChap-v2;
- Moxie Marlinspike | esec-pentest.sogeti.com