Google Summer of Code 2016

Project: Development of TLS library for KolibriOS
Organization: KolibriOS
Mentors: Jeffrey Amelynck,Pathoswithin
Student: Denis Karpenko
University: National Research University Higher School of Economics

Abstract

There is a tiny TLS 1.2 Library. It supports only one cipher suit TLS_RSA_WITH_AES_256_CBC_SHA256(strong cipher). According to specification it is enough for correct TLS connection.

What was actually done

• HMAC based on SHA256. Well tested! Stable
• Pseudo-random function based on HMAC. Well tested! Stable
• RSA exhange algortihm
• TLS handshake (complicated function)
• Basic TLS recieve function
• Basic TLS send function
• Combine together existing AES and SHA modules with my code into application, which succesfully connects to server
• Patched TLSEcho server for DebianOS to print all debug information
• Demo

What's left to do

• TEST!!! Main part was not enough tested
• TLS handshake. Make convinient function
• It is not completed library now. I need to make real library from application and library parts :)

Known Issues

• Encryption premaster key sometimes is wrong
• Application was not tested on chain of certificates

Plans for the future

• Optimize some parts of code
• Add more cipher suits
• Write wiki page about library
• Add extenstions
• Maintain library (TLS 1.3 is coming:))

Demo