SIP calls over cjdns

Following a recent discussion on IRC, I’m writing up a brief tutorial on how to make secure VoIP calls over a cjdns network (such as Hyperboria). Since cjdns encrypts everything end to end, there is no need to worry about ZRTP or other sorts of connection security. My computer is currently running Ubuntu 14.04 (Trusty), but this should work with most distros (obviously the install commands may vary by distro). I assume you’ve already got cjdns installed and you’re able to use it to communicate with others. If not, take a look at the cjdns README, then come back.

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Building a "Secure" Android App

This quarter I’m taking a class about security stuff. I figured it’d be somewhat interesting, but found, much to my dismay, that the instructor very lacking in any practical knowledge related to information security. The main assignment for the entire quarter is building a secure mobile payement system for on Android.

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Powerline, Minature Octo Batman, and more

Last week, after replacing my failing hard drive with an SSD and reinstalling my OS, I was playing with tmux and vim configs when I rediscovered Powerline. It’s a script to provide extensible statusline elements to a variety of things (including vim, tmux, i3, zsh, etc). I installed it into my tmux, and loved it so much that I ended up putting it on several of my servers as well. Many of the default modules are nice to have in the tmux stausline, athough I changed it a bit from the default.

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Scraping the UW course listings

I was boredly sitting in class earlier this evening when someone mentioned that he had been trying to scrape and parse UW’s course listings with python. I suggested BeautifulSoup, which he said he’d used, but it was still incredibly dfficult. I had to give it a shot myself. If you want to follow along, here’s one of the pages. Without looking at the source, it’s clearly a table or possibly a few of them, but still relatively easy to parse. However, looking at the source reveals that each timeslot of each course is in fact its own table, with one row and cell, which contains a <pre> tag, which has the “table” made by using the proper number of spaces to make everything line up. Like this:

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Keybase, a site for matching handles to keys

I recently found out about Keybase. From what I gather, it’s a way to allow one to associate their PGP public key with their Twitter, Github, etc (only Twitter and Github are supported at this time, it seems). At first I thought it required you to trust Keybase, but after playing with it a little I realized that the keybase client actually does the verification. Basically, you post a signed message to your Github and Twitter which says what your username on that service is, your username on Keybase is, and that this is your key. Have a look at my Github verification for an example.

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