Fire and motion

Straining at the Oars

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I'm burying my parents' ashes this week. I miss them. I miss them individually, and I miss them as a pair. And my missing of them is an active, conscious thing, not a passive background thing. I remember them vividly, and I could use their advice and love now, if they were here. This is going to be a hard week.

It's been a hard couple of months.

I'm not sure what the difference between grieving and depression is. What I mean is, I don't know where "the line" is, and how not to cross it. I know that what happened is the natural order of things. We are supposed to survive our parents. I also know that I'm working through this.

Rie Fu's song, "Life is like a Boat," came on while I was playing a favorite playlist. It's a love song, but it also touches on the hardships of life, and working your way through them to the other side. In the song, we "are all rowing the boat of fate / the waves keep on comin' and we can't escape."

The next part resonates with me:

You make me wanna strain at the oars
And soon I will see the shore
When will I see the shore?

At the same time she writes about fate and not being able to escape it, she sings about never giving up her effort. She doesn't see the shore, but she'll strain at the oars in the hopes that she soon will.

I'm straining at the oars, too.

Photo by wiserbailey / CC BY-NC 2.0

My Dead Man's Switch

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I wrote a dead man's switch to update some of my online accounts after I die.

What It Is

The basic idea is that if I pass away unexpectedly, I'd want my online friends to know, rather than for my accounts to go silent without any explanation at all. I wrote a program to take notice of whether or not I seem to still be alive, and once it's determined that I've died, it'll follow instructions that I've left in place for it. It'll do this over the course of a few days. Well, I won't tell you when it'll stop, that'd be taking some of the surprise out of it.

Two things caused me to do this. First, I wrote a lifestream. Essentially, I already wrote a computer program (a cron job, technically) that takes note of nearly everything I do online already. It was a handy thing to have, and it seemed like it could do just a little bit more with hardly any effort.

Second, I read the books Daemon and Freedom™. A character in those books also wrote a program (a daemon in his case) to watch over its creator's life, and then to take certain actions upon its creator's death. The idea got under my skin, and I just had to write a similar program of my own.

How It Works

This section will get technical, but it'll be of interest for those who also want to write their own.

Everything is in Python. The lifestream I have uses feedparser to read in and process each of the feeds affected by my online activity (sometimes called user "activity feeds"). It stores certain information in a yaml file. Here's an excerpt from the file itself.

-
  etag : 2KJcCROqtyI4nqaQEg34109rfx4
  feed : "http://my.dlma.com/feed/"
  latest_entry : 1326088652
  modified : 1326090583.0
  name : mydlma
  style : journal
  url : "http://my.dlma.com"

The most relevant item in the file is that there's a field called, "latest_entry", and the data for that field is a timestamp. The latest "latest_entry" would then be the most recent time I've been observed doing anything online.

Given that, all I had to do was write a new script that watched the latest "latest_entry", and when it became too long ago, it would assume that something bad had happened to me. (Which would be wrong, of course, if I was merely vacationing in Bora-Bora, and didn't have internet access for a couple of weeks.)

This new script would do something like the following:

  1. Continue to step 2 if David hasn't done anything online for a few days. Otherwise keep waiting.
  2. Decide which posts to make at which times, and make note that those posts themselves don't now make it look like David's still alive and that the switch should deactivate.

Once the script thinks I've been offline for too long, it writes a cookie to file, and then goes from watching mode to posting mode.

In posting mode, the script looks over its entire payload of messages to deploy. I used the filesystem to maintain the payload, much like dokuwiki does. (Others might think that a database would be preferable. Sure, that'd be fine, too.) My payload files encode data into the filename, too. The filename is composed like so: [delay_to_post]-[service_to_post_to]-[extra_info].txt. That way, when I display a listing of the directory, I can see an ordered list of which messages go when.

Message Delivery

Messages that go to blogging services like WordPress or Habari use the AtomPub API. Messages that go to other services generally use OAuth 2.0 for authentication, then use a custom API to deliver the message.

Once a message has been successfully delivered to its service, it gets moved or renamed in such a way that it's no longer a candidate to get delivered again.

Development Process

The script runs as a cronjob, and usually just updates a status file. If it runs into a problem, it sends an email. (Fat lot of good that'll do if I'm already dead. But while I'm still alive, I'd like it to let me know if it's not happy.)

While I'm alive, I might still add posts to post later. When I add those new messages to post after my passing, I need to ensure that I didn't do anything wrong. (For example, the Habari payload is contained in an XML CDATA section, but the WordPress payload is plain XML, so I can't write any malformed messages.)

That's why as a part of routine maintenance, my dead man's switch also does payload data validation.

During script refactoring, I may want it to display certain diagnostic info directly to stdout. For that case, the script has optional debug, test, verbose and validate flags.

Risks

There's always the false positive, where it thinks I've died, but the rumour was greatly exaggerated. I'm actually looking forward to a few false positives, because they'll remind me that the dead man's switch is actually still running.

Another serious risk is that my dead man's switch relies on the successful continuous operation of my lifesteam script. There's an element to that lifestream script that degrades over time. Hopefully, I'll get around to mitigating that risk.

And yet another risk to my dead man's switch is continuously changing APIs. As I upgrade my Wordpress and Habari blogs, will they still accept AtomPub like they did when I wrote the switch in 2012? Will Twitter and Plurk still use the same OAuth protocol and API calls? Heck, will Dreamhost not upgrade Python to a version that's incompatible with my script?

Will I still have active accounts at the time of my passing? Will it then be illegal to continue to function online after you're dead? (Some bozo might die before me and do something stupid after he passes.)

There's a lot that could go wrong. But if these things don't go wrong, and my dead man's switch works correctly, that'd be pretty neat.

Have I got things to say to you!

Photo by matthileo / CC BY-NC-SA 2.0

Internet Security

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Beware: I am a real neophyte when it comes to internet security. Having said that, I couldn't have fared any worse than Sony Pictures. They lost 1,000,000 plain-text passwords when a SQL injection vulnerability was discovered. I've been protecting against that attack since 2005. (At the part, "Is the password secure?" is where I say the passwords aren't stored in plain text. SQL injections have been the subject of security jokes for a long time, too. Ah, Little Bobby Tables.)

There have been and continue to be large breaches of personal data on the internet. Nathan Yau shares an infographic of the largest data breaches of all time.

My immediate family and I need a way to keep each other up to date with our changed account info and ID numbers. We need a solution that meets the following usability criteria:

  • Accessible anywhere, from any device. It has to be practically just one click away.
  • Trivial, memorable URL. We may be typing it directly into the URL bar.
  • Always up-to-date. Any change made from anywhere is accessible immediately from any other client.

If it's not that easy to use, it won't be used, and there'd be no point in making it. On the other hand, it has to have the following security criteria:

  • Accessible anywhere, from any device. It has to be secure even over a public wifi network.
  • Secure from remote client attacks. It has to handle attacks over the internet.
  • Secure from local attacks. It has protect against disgruntled hosting company employees.

With all that in mind, I've decided to roll my own information vault. Here are some goals and notes from that venture:

Be A Low Value Target

My first line of defense is that my information vault is just for me and my family. This'll never store enough data of real value to make it a target for the economics of it. I might get attacked, but it'd only be for the idle challenge of it.

Block Direct Access of Data Files

Move data files off the server, even though they're encrypted, or into directories tightly controlled by permission settings and .htaccess instructions. Test both attacks. If your encrypted files can fall into your attacker's hands, they can try a local brute force attack. (More on that below.)

Use HTTP Secure

For any data that is accessible, use HTTPS. This is the first line of defense if you want your data accessible over a public wifi network.

Unique and Long Master Password

Force your users to use a long random, impossible-to-guess master password. Prevent any sort of social attack: No names, dates, or places. In my case, since I'm the creator of the tool, I can do this.

Use a Hard-To-Compute Hash for the Master Password

Related: Do not store the master password anywhere. And the salted hash you use for it should be secure. Refer to this wikipedia article on cryptographic hash functions to see relative weaknesses of the functions. I've considered throwing in with a hashing algorithm that adapts to faster hardware to frustrate brute-force attacks.

Don't Store any Data in Plain Text

This is a defense against a local attack from someone who can obtain file-level access, like a company employee with admin access.

Sony Pictures stored private data in plain text format, and thus enabled this interesting analysis of passwords in the Sony Pictures security breach. Consider your encryption algorithm carefully. I used AES, but am keeping my options open. I can change my backend at any time.

Limit Cookie Scope

Limit your HTTPS cookie scope with morsels like max-age, httponly, domain, path and secure morsels.

While you're at it, it doesn't hurt to salt cookie and session data with an identifier associated with the request. In Python you could use os.environ['REMOTE_ADDR'].

Protect Against Javascript / SQL Injection

Know what kinds of attacks can be performed. Encode characters that have special meaning for the languages you use, like the quotes characters, <, >, and &, among others. In Python, the bare minimum you'd use is cgi.escape for that, but you'd want to use other functions depending on where/how the data is travelling or being displayed.

Analyze and Act Upon Suspicious Activity

It's not enough that your server is passively logging each access. Your site needs to analyze recent activity and take action (like email you or ban certain origins) when preset triggers are tripped.

Keep Protecting

Security is not a product, but a process." --Bruce Schneier, author of "Applied Cryptography"

This blog entry may have already has fallen out-of-date with new measures I've taken to protect our information vault.

If I'm missing a vector of attack, or you have some practical advice for me, I'd appreciate hearing from you.

Photo by Lawrence Lew, O.P. / CC BY-NC-ND 2.0

Arriving at the Answer

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In his article, The Importance of Vacation, Jonah Lehrer wrote the following:

When we feel distant from our work — when it seems wonderfully far away — we are able to think about work in a new way.

By thinking about problems in a new way, we can arrive at solutions we'd otherwise miss.

Jonah points this out as a benefit of going on vacation. While going on vacation can tickle your creative process when it comes to problem solving, you don't actually have to leave to get all of the benefits. Just feeling distant from the work is enough to get you to approach a challenge from new angles.

Jonah cites an experiment, the effect of spatial distance on creative cognition, where a psychologist ran two groups through the same set of insight puzzles, but told one group that the puzzles originated in a far away land.

Surprisingly, the group that was told the puzzles came from far away performed better. Why would simply telling somebody that the problem came from far away affect their ability to solve the puzzles? Jonah explains:

The sense of distance allowed these subjects to consider a far wider range of alternatives, which made them more likely to solve the challenging brain teasers. ... Instead of getting stuck and giving up, they were able to persist until the right answer appeared.

This is a technique that you can use, too. The next time you're struggling with a problem, do the following:

Imagine that the problem you're facing comes from a far away place.

Put some distance between you and the problem. With perseverance and a little luck, you'll arrive at the answer.


Photo by Stuck in Customs / CC BY-NC-SA 2.0

Take a Break

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In the not too distant future, my children are sure to come to me citing the 2007 study in the journal Pediatrics that says they should do the following things in the following order:

  1. Play video games.
  2. Do homework.
  3. Watch videos.

Nice try, kids. That's not exactly what the study says, but it does say that kids shouldn't play video games after doing their studies.

A New York Times article, Growing Up Digital, Wired for Distraction, cites the study, which was done at the German Sport University in Cologne.

The researchers looked at how [playing video games vs. watching a video] affected the boys’ brainwave patterns while sleeping and their ability to remember their homework in the subsequent days. They found that playing video games led to markedly lower sleep quality than watching TV, and also led to a “significant decline” in the boys’ ability to remember vocabulary words.

The New York Times article then references another study from the University of California at San Francisco:

Scientists have found that when rats have a new experience, like exploring an unfamiliar area, their brains show new patterns of activity. But only when the rats take a break from their exploration do they process those patterns in a way that seems to create a persistent memory.

We're all already bombarded by attempts to distract us. The trick is to know the value of our attention. As Leigh Reyes said, "Attention is the mind’s currency. Once we’ve spent it, we can’t buy it back." In order to get the value out of that transaction, the mind needs downtime to process and retain what it's taken in.

If you want to make the most of your studies, don't put them off until the last minute. Get them done, then take a break and let your brain absorb what it's learned.

  1. Do homework.
  2. Take a break.

Photo by Bart van Maarseveen / CC BY-ND 2.0

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