![[SimGuy.net]](/shared/logo.png){kind=logo}
January 2004 Archive
Sunday, January 18, 2004
[Comments: 0] 3:37 PM - admins-are-people-too
It occurred to me that in my SFTP without shell project, my sftp-server patch prevented administrator type accounts from being able to access the whole server. I think allowing root's group (wheel in this case) to SFTP without a chroot (assuming SSH is even accepting logins for root) is more correct.
Saturday, January 17, 2004
[Comments: 0] 2:12 AM - always-up-for-a-challenge
I just completely rearranged my projects page. In fact, the content is now spread across three new pages, for open source, web development, and web scripting.
My roommate also basically challenged me (or so I choose to interpret it) to make SFTP work on SimGames.net, even though users don't have shell access. By design, OpenSSH requires that the user have a valid shell so that he can execute a special SFTP server tool when he tries to log in.
When the user has an invalid shell, like in my case, SFTP simply will not work. The workaround is to make a pretend shell that will do nothing aside from launch the SFTP server program. This is then put in place of the invalid shell, and the user magically becomes able to use SFTP.
Another important thing that needed to be dealt with, however, is chrooting, or changing the way the file system appears to the user, so that it looks like his own account is all there is to see (and to prevent him from sneaking around elsewhere in the system). To do this, I also needed to find the OpenSSH source for the version installed with FreeBSD 4.7, which turns out to be version 3.4p1. I then had to modify the SFTP server program to automatically chroot the user and then drop itself to reduced privileges. (You can't chroot unless you are the super-user.)
All in all, everything worked out, and users can now use SFTP on SimGames.net, assuming they have an SFTP client, allowing them to better hide their plain text password from the snooping eyes of hackers.
Wednesday, January 14, 2004
[Comments: 0] 3:24 AM - random-fixination
I just realized that something I did a couple months ago made the form fields for submitting comments invisible. To accomodate anyone that isn't in the mood for lucky clicking, I've given them all borders again. :)
Also, there are now commas between the day of the month and the year in the blog dates. I'm not sure how I managed to get away without those commas for so long, given all the keen eyes that have had the opportunity to examine my site.
Tuesday, January 13, 2004
[Comments: 0] 11:57 PM - hell-has-frozen-over
Well, some people call this place Hell... and if this is Hell, it's a pretty damned cold place.
Since my return to Clarkson this past Wednesday, temperatures have not reached the freezing mark even once... and they're approaching from the bottom.
We had a little bit of a warm spell this past two days, with highs reaching very nearly 20°F, but the three days prior, highs never climbed much above 0°.
The real fun begins overnight tonight and up through Friday, though. Temperatures will not reach zero until Friday afternoon. In fact, Thursday's high is forecast to be -10° according to weather.com. To make matters worse, the forecast wind chill for noon on Thursday is -39°. At that temperature, units hardly matter, because -40° Celsius and -40° Fahrenheit are the same temperature.
I've been wondering what Clarkson's wind chill cutoff is (that is, the point at which classes are cancelled). If -40° isn't it, I sincerely hope we don't get a chance to see temperatures that actually warrant it!
I'll be staying inside my nice 70° room for now, but unless Clarkson has mercy on our souls, I'll be making the trek to the Science Center as quickly as possible tomorrow, and to reach Snell Hall on Thursday, I'll definitely do some building hopping. There's a good chance I'll opt for lunch in the apartment, come Thursday.
Sunday, January 11, 2004
[Comments: 0] 5:20 AM - t-minus-five-months-and-counting
... and so it begins, one last time.
I talk of the semester, of course, and this will be my final if all goes according to plan. There's a glitch I won't count or divulge because it all boils down to something trivial. All will go according to plan if I have anything to say about it.
Nearly all of my classes have attendance policies this semester. This is good. Not particularly wanting to fail should prevent any temptation I might have to accidentally miss one or two (or more) on a whim.
Aside from that, I think I may enjoy this semester a bit more than the last. I am taking two CS courses that interest me quite a bit:
Artificial Intelligence has always fascinated me, and while I've read and learned a bit about it, I really want to learn more. All the AI I've ever come across has been relatively unimpressive for production use, but the underlying concepts have potential, and I want to learn how some of them tick.
Computer Communication (I can't remember where the course web page is right now) is a course that relates to computer networking concepts, especially related to the Internet. This is an area I love, and much of what I know has come from administering a web hosting server. I want more!
The other classes I'm taking may not be as interesting, but one deals with movies and even includes a (scheduled) three hour lab where we watch them. Hopefully it won't take the full three hours each time around. I'm also taking a documentation course, an independent study, which should be closely related to the former, and a management course that I expect to be the most challenging to remain interested in.
We'll see what I think once I have projects to do.
On the subject of posting to my weblog, I will endeavor to post more often. I have much to say, and I tend to forget I have someplace to say it. If I forget, hit me.
