The challenge with Postfix, or with any piece of software, is to update software without introducing problems. Wietse Venema More Quotes by Wietse Venema More Quotes From Wietse Venema Defect-free software does not exist. Wietse Venema softwaretechnologydoe However, writing software without defects is not sufficient. In my experience, it is at least as difficult to write software that is safe - that is, software that behaves reasonably under adverse conditions. Wietse Venema experiencesafewriting Most of the effort in the software business goes into the maintenance of code that already exists. Wietse Venema maintenanceeffortbusiness Sure, but competition is good for the user. Wietse Venema userscompetition Like all software, Qmail can survive only when it keeps up with changing requirements. Wietse Venema requirementssoftware My reply is: the software has no known bugs, therefore it has not been updated. Wietse Venema knownbugssoftware One bug in an SMTP server can open up the whole machine for intrusion. Wietse Venema intrusionmachinesbugs Postfix keeps running even if one Postfix process dies; Windows requires that someone restarts the service. Wietse Venema processrunningwindow Qmail out of the box works fine, so people will want to use it regardless of licensing restrictions, even when the software does not ship with their system software. Wietse Venema usedoepeople The Postfix security model is based on keeping software simple and stupid. Wietse Venema softwaresimplestupid Windows favors multi-threading, which means that a service is implemented by one single process. Wietse Venema favorsmeanwindow Writing software that's safe even in the presence of bugs makes the challenge even more interesting. Wietse Venema challengeswritinginteresting As of today, the Postfix mail transport agent has almost 50,000 lines of code, comments not included. Wietse Venema agentslinesmail I want to avoid locking people into solutions that work only with Postfix. People should have a choice in what software they want to use with Postfix, be it anti-virus or otherwise. Wietse Venema choicesshould-havepeople When I write software, I know that it will fail, either due to my own mistake, or due to some other cause. Wietse Venema causesmistakewriting Lack of documentation is becoming a problem for acceptance. Wietse Venema documentationbecomingacceptance I don't expect an overnight change of all desktops to what the US Military used to call B3 level security. And even that would not stop users from shooting themselves into the foot. Wietse Venema changemilitaryfeet Coming back to the topic of computer security, the TCP Wrapper is an example of such a safety net. I wrote it when my systems were under attack by someone who appeared to walk through walls. Wietse Venema wallsafetyexample This will surprise some of your readers, but my primary interest is not with computer security. I am primarily interested in writing software that works as intended. Wietse Venema computersurprisewriting At the time the Sendmail program had a very poor reputation with respect to security, with four root vulnerabilities per year for two successive years. Wietse Venema respecttwoyears
