Previously, Strongbox, my gem for using Public Key Encryption with ActiveRecord, allowed only one key pair for encrypting all of the records for a given ActiveRecord model. I’ve had a number of requests to make it possible to dynamically choose the keys on a per record basic and version 0.6.0 adds this feature.
The values of :public_key, :private_key, and :key_pair can be in one of the following formats:
A string containing path to a file. This is the default interpretation of a string.
Using this, you can automatically create per record public keys:
require'openssl'# Assumes the migration contains:# t.string :description# t.binary :secret# that you are collecting a password to encrypt the private key,# and that the secret is smallclassUser<ActiveRecord::Baseattr_accessor:passwordencrypt_with_public_key:secret,:key_pair=>:key_pairdefafter_initializersa_key=OpenSSL::PKey::RSA.new(2048)cipher=OpenSSL::Cipher::Cipher.new('des3')key_pair=rsa_key.to_pem(cipher,self.password)+rsa_key.public_key.to_pemendend
Important Caveat –
Currently, Strongbox encrypts the attribute as soon as it’s assigned (this will change in version 1.0). The means that the public key must be available before the attribute is assigned, hence the use of after_initialize to generate the key pair. Even so, this will fail if you do something like:
because the attributes are set before after_initialize is called.
As always, I like building Emacs for my Mac from
source. It lets me live on the cutting edge and have tigher control
of the version I’m running. If building software from source isn’t
your thing then skip the rest of this article and consider installing
Emacs using Homebrew,
I’ve written about building Emacs in the past, but OS X Lion brings a few
complexities to the process.
After years of running on Wordpress, today I’m relaunching my blog using Octopress. Octopress is a blogging framework build on top of Jekyll which in turn is system designed for publishing static sites from source files, be they Markdown, HAML, SASS, etc. This style fits nicely in to my everyday workflow, so my hope is it will get me writing on a regular basis.
Wordpress is great if you want a WYSIWYG blog and I still recommend to my clients. But, if you spend your days in Emacs or Vim, running rake tasks and git commits, you might want to give Octopress a try.
However, there is a downside: Pow doesn’t play nicely with Apache (or any server listening on port 80). Life isn’t all greenfield, if in the course of the day you need to work on PHP or CGI legacy apps Pow is not so simple. Pow creates a firewall rule that redirects port 80 to its port; to access Apache you need to either toggle the firewall rule on and off or move Apache to a different port all together. And now you’re running two web servers. There has to be a better way.
And there is, make your legacy app a Rack App. Thanks to the rack-legacy gem, this is actually quite simple.
Rack::Legacy::Php runs any requested file with the extension .php. Rack::Legacy::Cgi runs any requested file that is set executable (which means you’ll need to make sure your .html files are not). Files that don’t end in .php and aren’t executable are served as static content by Rack::File.
The INDEXES array contains a list of files to check for if a directory is requested (just like Apache’s DirectoryIndex directive). You can change the order or use different names (default.htm anyone?).
rack-legacy uses the php-cgi command line program to run scripts and while PHP ships with current versions of OS X, php-cgi is not included. You’ll need to install PHP using MacPort/Homebrew/Fink/etc. That’s beyond the scope of this post but, if you’re doing this kind of development, it’s probably not beyond you.
This is probably not a fast as running PHP using the Apache module and it’s certainly not as fast as something like FastCGI. If you are primarily developing legacy apps you probably should stick to Apache. However, if you mostly work with Rack apps and just occasionally need legacy support, this is a great way to go.
There’s plenty of documentation on how to deploy “Classic” style Sintra applications with Phusion Passenger, but it’s not immediately obviously how to deploy the new “Modular” style app (created with Sinatra::Base). Fortunately, it’s simple, the resulting class can be passed to “run” inside you “config.ru” file, something like:
Instructions you find for “Classic” Sintra apps have you setting “:env” to the ENV[‘RACK_ENV’] before running the app. As of Sintra 1.0 it’s “:environment” and it’s automatically set to
ENV[‘RACK_ENV’] (or “:development” if RACK_ENV is not set). You’ll also see instructions for setting “:run” to false, this is not nessecary for “Modular” apps.
Instead of having a dedicated login page, some sites return a 403 Forbidden HTTP status code and include the login form in an HTML body of a custom 403 page. For example, Drupal admin pages work this way. While this may seem a little odd, it works; all modern browser will display the HTML and few, if any, will note the Forbidden status.
Mechanize on the other hand raise an exception when it receives a 403 status. Fortunately, it returns the page it received as part of that exception. Here’s how to handle it:
mechanize=Mechanize.newbeginlogin_page=mechanize.get("http://localhost/admin")rescueMechanize::ResponseCodeError=>exceptionifexception.response_code=='403'login_page=exception.pageelseraise# Some other error, re-raiseendendlogin=login_page.form_with(:action=>'/login')do|f|f.field_with(:name=>'user').value=userf.field_with(:name=>'password').value=passwordend.submitraise'Login Failed'iflogin.body!~/Logged in!/
This code also works in the case where you don’t get a forbidden status, so it can be used generically.
For bonus points you can use the same code in a Cucumber step by changing:
2048 is the key size, and a good value to use for it.
What’s not obvious is how to encrypt the private key. You don’t have to encrypt it, but, if you don’t, anyone who gets a hold of the key can decrypt your data. Using an unencrypted private key gives you one layer of security (something you have – the key), encrypting it gives you an additional layer (something you know – the password).
To encrypt the private key you need a Cipher object:
Then, using the Cipher object, you convert the the key_pair to PEM format: