php - Dave's Blog

Let's Encrypt NearlyFreeSpeech.net Setup

curl -o domain.chn https://letsencrypt.org/certs/lets-encrypt-x1-cross-signed.pem

RewriteEngine on
RewriteCond %{HTTP:X-Forwarded-Proto} !https
RewriteRule ^.*$ https://%{SERVER_NAME}%{REQUEST_URI} [L,R=301]

Header set Strict-Transport-Security "max-age=3600;" 

Stripe CTF - Input validation (Levels 1 & 2)

          $filename = 'secret-combination.txt';
      extract($_GET);
      if (isset($attempt)) {
        $combination = trim(file_get_contents($filename));
        if ($attempt === $combination) {

    $dest_dir = "uploads/";
    $dest = $dest_dir . basename($_FILES["dispic"]["name"]);
    $src = $_FILES["dispic"]["tmp_name"];
    if (move_uploaded_file($src, $dest)) {
      $_SESSION["dispic_url"] = $dest;
      chmod($dest, 0644);
      echo "
Successfully uploaded your display picture.
";
    }

Stripe Web Security CTF Summary

DVD Ripping and Viewing in Windows Media Center

I've just got a new media center PC connected directly to my television with lots of HD space and so I'm ripping a bunch of my DVDs to the PC so I don't have to fuss with the physical media. I'm ripping with DVD Rip, viewing the results in Windows 7's Windows Media Center after turning on the WMC DVD Library, and using a powershell script I wrote to copy over cover art and metadata.

My powershell script follows. To use it you must do the following:

1. Run Windows Media Center with the DVD in the drive and view the disc's metadata info.
2. Rip each DVD to its own subdirectory of a common directory.
3. The name of the subdirectory to which the DVD is ripped must have the same name as the DVD name in the metadata. An exception to this are characters that aren't allowed in Windows paths (e.g. <, >, ?, *, etc)
4. Run the script and pass the path to the common directory containing the DVD rips as the first parameter.

Running WMC and viewing the DVD's metadata forces WMC to copy the metadata off the Internet and cache it locally. After playing with Fiddler and reading this blog post on WMC metadata I made the following script that copies metadata and cover art from the WMC cache to the corresponding DVD rip directory.

Download copydvdinfo.ps1

I'm Married!

Did I mention that I got married two weeks ago today on May 29th? Its true! Our wedding was a kind of planning singularity -- all of my planning efforts would get sucked into that day and I couldn't make any plans past that date. But the actual wedding itself was lovely and I didn't feel nearly as stressed out or nervous during the wedding as I did trying to plan for it. I've been gathering wedding photos on our wedding website photos page.

Android eBook Reader And Makers

I was reading Makers, Cory Doctorow's latest novel, as it was serialized on Tor's website but with no ability to save my place within a page I set out to find a book reading app for my G1 Android phone. I stopped looking once I found Aldiko. Its got bookmarks within chapters, configurable fonts, you can look-up words in a dictionary, and has an easy method to download public domain and creative common books. I was able to take advantage of Aldiko's in-app book download system to get Makers onto my phone so I didn't have to bother with any conversion programs etc, and I didn't have to worry about spacing or layout, the book had the correct cover art, and chapter delimiters. I'm very happy with this app and finished reading Makers on it.

Makers is set in the near future and features teams of inventors, networked 3d printers, IP contention, body modifications, and Disney -- just the sort of thing you'd expect from a Cory Doctorow novel. The tale seems to be an allegory for the Internet including displacing existing businesses and the conflict between the existing big entertainment IP owners and the plethora of fans and minor content producers. The story is engaging and the characters filled out and believable. I recommend Makers and as always its Creative Commons so go take a look right now.

Blog Layout and Implementation Improvements

I've redone my blog's layout to remind myself how terrible CSS is -- err I mean to play with the more advanced features of CSS 2.1 which are all now available in IE8. As part of the new layout I've included my Delicious links by default but at a smaller size and I've replaced the navigation list options with Technical, Personal and Everything as I've heard from folks that that would actually be useful. Besides the layout I've also updated the back-end, switching from my handmade PHP+XSLT+RSS/Atom monster to a slightly less horrible PHP+DB solution. As a result everything should be much much faster including search which, incidentally, is so much easier to implement outside of XSLT.

Platonic Ideals in Anathem and The Atrocity Archives

On the topic of made up words: I get made up words for made up things, but there's already a name for cell-phone in English: its "cell-phone". The narrator notes that the book has been translated into English so I guess I'll blame the fictional translator. Anyway, I wasn't bothered by the made up words nearly as much as some folk. Its a good thing I'm long out of college because I can easily imagine confusing the names of actual concepts and people with those from the book, like Hemn space for Hamming distance. Towards the beginning, the description of slines and the post-post-apocalyptic setting reminded me briefly of Idiocracy.

Recently, I've been reading everything of Charles Stross that I can, including about a month ago, The Jennifer Morgue from the surprisingly awesome amalgamation genre of spy thriller and Lovecraft horror. Its the second in a series set in a universe in which magic exists as a form of mathematics and follows Bob Howard programmer/hacker, cube dweller, and begrudging spy who works for a government agency tasked to suppress this knowledge and protect the world from its use. For a taste, try a short story from the series that's freely available on Tor's website, Down on the Farm.

Coincidentally, both Anathem and the Bob Howard series take an interest in the world of Platonic ideals. In the case of Anathem (without spoiling anything) the universe of Platonic ideals, under a different name of course, is debated by the characters to be either just a concept or an actual separate universe and later becomes the underpinning of major events in the book. In the Bob Howard series, magic is applied mathematics that through particular proofs or computations awakens/disturbs/provokes unnamed horrors in the universe of Platonic ideals to produce some desired effect in Bob's universe.

Thoughts on registerProtocolHandler in HTML 5

I'm a big fan of the concept of registerProtocolHandler in HTML 5 and in FireFox 3, but not quite the implementation. From a high level, it allows web apps to register themselves as handlers of an URL scheme so for (the canonical) example, GMail can register for the mailto URL scheme. I like the concept:

• Better integration of web apps with your system.
• Its easy for web apps to do.
• Links to URNs can now take the user to the sites the user prefers for the sort of thing identified by the URN. For example, if I have a physical address in HTML, instead of making that an http link to Yahoo Maps, I can make the link a geo scheme URI and those who follow the link will get their preferred mapping site that has registered for that scheme. Actually, looking at the geo scheme's RFC, maybe I'd rather use some other URN scheme to represent the physical location, but you get the point.

• There's no way to know if you are the handler for a particular URL scheme which is an important question for web app URL protocol handler authors.
• There's no way to fallback to an http URL in the case that a particular URL scheme isn't registered. A suggested solution to testing the registration of a scheme is for browsers to provide an additional script method to check if a scheme is registered. I don't like the idea of writing script that walks over all my page's links and rewrites them based on that method. I'd much rather see a declarative and backwards compatible fallback mechanism, although I don't know what that would look like.
• There's no way to register for a namespace within the urn scheme URI, the info scheme URI, or the tag scheme URI. I want to register info:lccn/... (Library of Congress Card Number identifiers) to LibraryThing or Amazon and I want to register urn:duri:... (dated URIs) to the Web Archive, among other things.


• Will this result in a proliferation of unregistered URL schemes with clashing namespaces? The ESW Wiki notes why this would be bad.
• And last, although this is nitpickier than the rest, I don't like the '%s' syntax used in the registration method. I'd much rather pass in an URL template, like the URL template used in OpenSearch. If an URL template is used for matching rather than registering against a particular URL scheme, this could also allow for registering a namespace within a URN. For example something along the lines of: registerProtocolHandler("info:lccn/{lccnID}", "htttp://www.librarything.com/search_works.php?q={lccnID}", "LibraryThing LCCN")

Halloween and Gas Park Weekend

The weekend before last Sarah and I went down to Gas Works Park in Seattle. Gas Works Park is a former Seattle Gas Light Company gasification plant now turned into a park with the machinery kept intact and found right on the shore of Lake Union. There's a large hill right next to the plant with an embedded art installation from which you get an excellent view of the park and the lake. Anyway a very cool place. Afer, we ate at Julia's of Wallingford where I stereotypically had the Santa Cruz omelet. Good food, nice place, nice neighborhood.

This past weekend was Halloween weekend. On Halloween at Microsoft parents bring their kids around the office buildings and collect candy from those who have candy in their office. See Matt's photo of one such hallway at Microsoft. The next day Sarah and I went to two birthday parties the second of which required costume. I went as House (from the television show House) by putting on a suit jacket and carrying a cane. Sarah wore scrubs to lend cred. to my lazy costume. Oh yeah and on Sunday Sarah bought a new car.

Investigation of a Few Application Protocols (Updated)

Windows allows for application protocols in which, through the registry, you specify a URL scheme and a command line to have that URL passed to your application. Its an easy way to hook a webbrowser up to your application. Anyone can read the doc above and then walk through the registry and pick out the application protocols but just from that info you can't tell what the application expects these URLs to look like. I did a bit of research on some of the application protocols I've seen which is listed below. Good places to look for information on URI schemes: Wikipedia URI scheme, and ESW Wiki UriSchemes.