I mentioned in my last post Shared console sessions that I would have an update to get near same functionality without setuid of the screen binary. Well here it is. Hopefully you are aware of expect and how it can be used to automate interactive programs like telnet. Expect is has many more uses that people are exploiting. Enter kibitz. Continue reading

I have had several posts regarding screen. Hopefully you have already realized the greatness of screen. Screen has a great feature that allows screen sessions to be shared. To my knowledge there are two ways to use this feature. First you can connect to a screen multiple times as the same user. Second you can use the multiuser mode of screen. Continue reading

I’m not really certain how common corporate sabotage is. Sure there are DOS attacks daily on this or that network or this or that server but what percentage of those are script kiddies and what percentage are well thought out planned attacks designed to cripple a competitor even if only for a short time. Typically DOS attacks are dealt with by Server and Network Admins adding black holes to offending networks. Recently while doing some research I stumbled on what seems to be a neglected DNS attack. One that the target may not become aware of until the next billing cycle or if carried out methodically months. Continue reading

Being able to send email manually seems to be a bit of a lost art. It is extremely handy to know how to use telnet to send email for testing procmail filters, and any other part of your mail system. It can also be fun to spoof email to a friend or co-worker. Read on for a quick run down. Continue reading

I generally don’t have any issues knowing someone might be snooping on a bit of my traffic. However there are times you may want your traffic to be a bit more private. For example if your boss is a raging tyrant and your looking for a new job, and you know the sky would fall if he found out you emailed or happened to be on Career Builder or for that matter had even the slightest idea of abandoning him. Yes I am recounting something from my past, hey at least its distant past :). So if you find yourself in that situation read on for how to use tsocks and ssh as a simple proxy.
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SSH is a powerful tool. When combined with ssh keys, it becomes easy to automate remote procedures like backups. However leaving key access wide open can be a bad idea. It is possible to use restrict ssh keys to specific commands, even coming from specific hosts. There is this nice little perl script called Authprogs that makes this somewhat easier. Ill show you how to use authprogs for an automated rsync over ssh.
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Yes its been a while since I have checked in. Sorry I’ve just been too busy. But I have a great tip this time. Recently I had the need to do automatic session logging. A 3rd party was going to be logging into one of my servers to check out some software glitches that were happening. I love using GNU Screen for many shell tasks so using it for monitoring was logical. Screen is great for several reasons. First you can detach from it so you can leave the office, go home and re-attach and not have lost your place. Second, you can share another screen. It can be shared input or you can just watch what someone else is doing. Finally screen can do native logging. I wanted to automattically launch a screen session when somone logged in so if I happened to be on the server I could monitor them in real time. I also wanted a log of the session in case I wanted to look over it later or if I was not able to monitor the session live.
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