MLS for Thunderbird, final word (for now)

As mentioned a few times, I have (had) two students working on a Thunderbird extension to support confidentiality and help avoid involuntary leaks of critical information by e-mail. Yesterday, these students officially turned this project in, which gave me and my colleagues the opportunity of reviewing the code and documentation.

So, what works ?

• The Thunderbird extension can detect that you’re trying to send e-mail to someone with a lower level of accreditation — although, for the moment, it gets confused easily. For this purpose, it may use either SELinux or a text database of recipients.
• The Thunderbird extension can warn you that you need to sanitize and decrease confidentiality of the information and can mark the outgoing e-mail as sanitized for a given level — the UI needs a bit polish, but that works.
• The Sendmail extension can detect that you’re trying to send e-mail to someone with a lower level of accreditation — although, for the moment, it gets confused just as easily and is subject to a number of security holes.
• The Sendmail extension can reject unsanitized e-mail going to unaccredited targets — logging needs a bit of polish, but that works.
• That’s it.

All in all, that’s about 150 lines of code in JavaScript, XUL, C and C++. Not quite ready for prime-time but a good 0.1 release. I expect either the students or I will upload it somewhere for public release in the near future.

MLS for Thunderbird, updated

A few months ago, I introduced “MLS for Thunderbird“, an on-going effort to add support for confidentiality in Thunderbird. After long months of silence, it seems that this student project, undertaken by Vincent Tarbouriech and Roland Thaisong, two Master Students in ENSI Bourges, is finally getting somewhere.

This extension interfaces with the underlying operating system (SELinux for now) to determine your security level and, if possible, that of your correspondants. If you attempt to send an e-mail to some recipient whose security level is inferior to yours, Thunderbird will warn you that a declassification is going to happen.

MLS for Thunderbird or “O gosh, perhaps I shouldn’t have sent confidential info to a public mailing-list”

This entry is a brief presentation of an on-going work in progress by a group of my students in ENSI de Bourges, Vincent Tarbouriech and Roland Thaisong.

The problem

If your daily work is to deal with sensitive subjects, whether in a laboratory, in the industry, in an administration or in a newspaper, chances are that your computer will host a number of confidential informations. By definition, if someone who doesn’t have the necessary credentials gets their hands on this information, you’re in trouble.

As long as the information remains on your computer and your computer uses a reasonably safe operating system and you’re behind a reasonably safe firewall and you don’t need to communicate any information to anyone, you should be reasonably safe from malicious third-parties. However, if e-mail happens to be one of your work tools and if you may need some of that information to some people but not to others, accidental leaks become a definite possibility.