My keychain Tool
I wrote a little script in ruby which manages passwords. It is a strictly command line tool and allows you to store keys, retrieve them, and even generate more or less pronounceable passwords of arbitrary length using a Markov chain. All the data is stored in a blowfish-encrypted file and should therefore be somewhat safe.
Since the script depends on two other ruby gems (namely crypt and highline), I’ve uploaded it to rubyforge. You can now simply install the script with
gem install keychain
The interface is quite easy, you can either pass the command as first argument, or invoke keychain which then enters an interactive mode. Simple try
keychain help
to see a list of commands.
Needless to say, I cannot guarantee that this tool will not one day
forget all your valuable passwords, but at least I can assure you that
I’m personally trusting my code. :)
Nokia E61i
I own a Nokia E61i since last December and all in all I must say that it has been quite an agreeable experience. It is solidly build, has a small but usable keyboard, real multitasking, a large screen and a really nice browser which even support JavaScript. Recently I found out that it supports the SIP standard for Voice Over IP which integrates very nicely with many “open” commercial offerings. Using a software called JoikuSpot even turns your cell phone into a WiFi HotSpot, giving you almost config-free access to the Internet wherever you are (okay, only for http in the free version).
Maybe the weakest component (and incidentally one of the most important) is the messenger, and I like to elaborate a bit on the small weaknesses and nuisances of that piece of software. Nokia, if you’re reading this, I politely ask you to consider fixing these things in the next update! Just do it. Pleeease!
Robustness
Generally, the phone is quite robust software-wise. It almost never locks up, and even if it does, you can usually still kill the program easily (How? Push the “Swirl” button for a few seconds, scroll down to the program and press the backspace key). However if there is one program which hands more often than others, it’s the messenger.
Now, you would expect that having unstable connections is really part of the life of a cell phone. After all, it’s a mobile device which means that it’s position is constantly changing and reception may be quite unstable. Still, whenever the phone tries to connect but really can’t, it decides that it’s safer to turn off the automatic retrieval. I wonder if just waiting for few minutes wouldn’t be a more reasonable alternative.
So if you can connect but something happens during the connect, the mail software also really likes to die in a number of less obvious ways. Sometimes it claims that it is still connected to the mailbox, but actually it isn’t. If you start to read emails, they vanish. If you manually close the connection is closed, it sometimes helps but often it doesn’t.
All in all, I know that IMAP is a complex protocol, but pleeease couldn’t you try to make the error handling a bit more reasonable?
Certificates
The other big nuisance is that automatic retrieval only works when you have the certificate of the server. Now if you’re working for a big company (which might be using Exchange anyway), which has paid enough money to get decently trusted certificates, everything’s okay, but when you’re working at a university, or try to sync emails from your own server, you’re out of luck.
The situation might not be entirely bad if there would be some way to install missing certificates easily. For example in the dialog for untrusted certificates. I wonder why they chose not to allow that… .
So how do you get the certificate on the phone? First of all, you have to obtain the certificate. If you’re lucky, there is some web page where you can download the certificate. Now you only have to pray that the web server is setting the correct mime type and everything’s good.
If not, you have to get the certificate. After some trial-and-error I found that the Internet Explorer (but not Firefox or Thunderbird) allow to safe a certificate to disc. So again if you’re lucky, the same certificate is used for secure web connections and you can safe that certificate.
Well, so how do you get the certificate on the phone? Putting the certificate somewhere on the phone using the file explorer won’t work, because the phone doesn’t recognize certificates in it’s own file browser. So either you’ve to mail it to you (saying one more time that yes, I want to connect to that server), again hoping that the mime types will be set correctly, or you have to put it somewhere on the web from where you can then download it.
To cut a long story short: Nokia, please let us install certificates whenever we encounter an untrusted one.
Hyperlinks
Finally, one last nuisance is that (at least on the E61i, other versions of Symbian might have only one browser for Internet and WAP) if you click on a link in a message, the WAP browser is opened, not the Internet browser. Which really doesn’t make any sense.
Nokia, will you help me out?
Update: If you’re running Linux, you might try the following “one-liner” to get the certificate from a server
echo "quit" | openssl s_client -connect server-address:server-port |\
ruby -e 'flag=false; readlines.each {|x| flag ||= (x =~
/BEGIN CERT/); if flag then puts x end; flag &&= !(x =~ /END CERT/) }' |\
openssl x509 -outform DER >cert.der
Replacing “server-address:server-port” with your server information, of course.
Update: Even if you install the server certificate on the phone, it may still be that the signing certificate is unknown. Using the Internet Explorer, you can save all those other certificates as well, and you have to install them all to make the phone accept the server certificate. I haven’t yet figured out how to do this with openssl, though… .
Static MVC
Update Feb 4, 2009: I recently learned about Jekyll, which puts these ideas into a solid framework.
I know that web applications and content management systems are the hot thing right now (and maybe will be for some time), but sometimes you wonder whether a few static html pages wouldn’t be sufficient anyway. The advantages are pretty clear: No database back-end, no tweaking of apache configurations, and of course, nothing beats static html pages in terms of speed and memory requirements.
On the other hand, editing html pages by hand seems so “old-school”, and there are some real maintenance issues. Appearance can be nicely controlled by CSS, but if you actually want to move bits of information around, you have to do it yourself. And let’s just hope that you haven’t gotten into adding some nice Javascript effects to your pages… .
This approximately describes the situation I was in when I decided to restructure my own homepage.
It turns out that it is actually possible to write a page generator along the principles used in web frameworks such as rails and end up with something quite elegant. And it’s fun, too!
Some of the power of a framework like rails comes from a clear separation between data, business logic, and presentation. This kind of separation is also called the MVC-Pattern (Model-View-Controller). All the data is typically stored in a database like MySQL, and the presentation is encoded in template files.
So how can we duplicate this kind of separation with a static page-generator? Luckily, ruby comes with all the tools you need. Let us walk through a little example, the inevitable blog (without commenting functionality, of course).
Let’s start with the database. We will just store all the information into YAML files. YAML is a file format which puts special emphasis on being easy to read and maintain by a human. The format is pretty self-explanatory:
- date: August 4, 2008
title: Same old, same old
text: |
Sometimes, you just wake up with that feeling that something
great is happening today. I couldn't really lay my finger on
it, but I was very sure that...
- date: August 6, 2008
title: You wouldn't believe
text: |
You know when I said that something great would happen two
days ago? And you know what...
This file contains two entries, encoded as hashes. The “|” indicates indented multi-line data.
Using the YAML library, you can easily load this data with
require 'yaml'
blog = YAML::load_file('blog.yaml')And if you inspect blog you will find that is an array of two hashes.
Next, we need to render the result. We’ll use the erb library, which you might know from rails. Here is a possible template file
<html>
<head>
<title>My little static blog</title>
</head>
<body>
<% for b in blog %>
<h1><%= b['title'] %></h1>
<p><em><%= b['date'] %></em></p>
<p><%= b['text'] %></p>
<% end %>
</body>
</html>(Almost looks like were coding in rails, right? :))
Let’s finally put all things together. We store the YAML file in blog.yaml and the template file in blog.rhtml. Then, the following script will generate blog.html:
require 'yaml'
require 'erb'
blog = YAML::load_file('blog.yaml')
blog_template = open('blog.rhtml').read
html = ERB.new(blog_template).result
open('blog.html', 'w') {|o| o.write html}And here is the result:
This way, you can easily add new posts by editing just the YAML file, and fiddle with the presentation in the template file. You’re not even restricted to a fixed number of pages, you could, for example, also generate a separate (static) page for each individual post (dynamically) by the script.
And it doesn’t stop here, adding a lightweight markup engine like BlueCloth you can even start using wiki-style markup in your texts.
So, it doesn’t always have to be a full fledged web application framework, you can have similar flexibility (minus the interactivity, of course), using a few readily available tools, and very few lines of code as well.