SolarScale Blog

Random Hackepedia

The RH for this week is Pid.

Watching the ISS

The past few days in Germany have been hot but the nights are cooler with mostly clear skies. This gave me an opportunity to see the ISS twice in the late evening (around 11PM). Once it was unexpected and we weren't sure what it was. The second time I got the data from the NASA sightings page, which is found here.

The space station looks like a flying jet but you'll notice that it doesn't blink nor does it have red and green lights. It's just a continuous and steady crossing of the sky mostly coming from the west towards the east. Without the moon and planets it's probably the brightest object in the sky as it zips at 28,000 Km/h's into the night. Anyhow it was a nice experience seeing this (it was my first time).

Fire has SSL support

Believe it or not I have made an IRC client. It's called fire and I've coded SSL support into it yesterday and today. The SSL functionality seems to be stable, you can download the source code here.

The Korean incident: tcpwrappers

I was checking my logs yesterday when I noticed that someone from an IP in Korea was trying to brute force my pop3 daemon. I noticed after they got about 6000 attempts in. So I looked at wrapping them with tcpwrappers. The pop3 daemon on the outside of solarscale.de is Dovecot and they by default don't have tcp wrappers support. But there is a patch. So I applied it and noticed that some hunks of the patch failed. Particularely near the configure scripts so I ended up editing config.h myself and added the define for tcp wrappers in it. Then I built it and noticed that it would bomb out in 2 spots, all it needed was an edit in the Makefile to add "-lwrap" in the LIBS= line. Then it built. When it was installed I noticed that my changes to /etc/hosts.{allow,deny} were not effective. So I did a bit of googling and read that Dovecot is chrooted. So it was just a matter of finding the chroot and putting its own hosts.deny in there. It worked. So now only a select number of hosts can use the pop3 service.

goldflipper% telnet solarscale.de 110
Trying 62.75.160.180...
Connected to solarscale.de.
Escape character is '^]'.
Connection closed by foreign host.

The patch is found here.