Advogato: Blog for etbe

3 Sep 2008 etbe » (Master)

Google Chrome - the Security Implications

Google have announced a new web browser - Chrome [1]. It is not available for download yet, currently there is only a comic book explaining how it will work [2]. The comic is of very high quality and will help in teaching novices about how computers work. I think it would be good if we had a set of comics that explained all the aspects of how computers work.

One noteworthy feature is the process model of Chrome. Most browsers seem to aim to have all tabs and windows in the same process which means that they can all crash together. Chrome has a separate process for each tab so when a web site is a resource hog it will be apparent which tab is causing the performance problem. Also when you navigate from site A to site B they will apparently execute a new process (this will make the back-arrow a little more complex to implement).

A stated aim of the process model is to execute a new process for each site to clear out the memory address space. This is similar to the design feature of SE Linux where a process execution is needed to change security context so that a clean address space is provided (preventing leaks of confidential data and attacks on process integrity). The use of multiple processes in Chrome is just begging to have SE Linux support added. Having tabs opened with different security contexts based on the contents of the site in question and also having multiple stores of cookie data and password caches labeled with different contexts is an obvious development.

Without having seen the code I can’t guess at how difficult it will be to implement such features. But I hope that when a clean code base is provided by a group of good programmers (Google has hired some really good people) then the result would be a program that is extensible.

They describe Chrome as having a sandbox based security model (as opposed to the Vista modem which is based on the Biba Integrity Model [3]).

It’s yet to be determined whether Chrome will live up to the hype (although I think that Google has a good record of delivering what they promise). But even if Chrome isn’t as good as I hope, they have set new expectations of browser features and facilities that will drive the market.

Update: Chrome is now released [4]!

Thanks to Martin for pointing out that I had misread the security section. It’s Vista not Chrome that has the three-level Biba implementation.