Magnet URI Redirect Service

This service is for those who wish to link to files on P2P file sharing networks, particularly Gnutella, but can't seem to get magnet URIs to work in their system. To use, create a link like:

• http://magnet.pixelcort.com/urn:sha1:YNCKHTQCWBTRNJIV4WNAE52SJUQCZO5C/king.mp3

The first part is the URI representing exactly the file, usually a URN Base32 SHA1 of the file, the second part the file name to save as. You can use the scripts below to help you build links like this.

The service will return a 302 Found with the magnet URI in the Location header, which would look like:

• magnet:?xt=urn:sha1:YNCKHTQCWBTRNJIV4WNAE52SJUQCZO5C&dn=king.mp3

Your browser should then pass it off to the correct program. For Mac OS X, this is done via LaunchServices, where Acquisition registers 'magnet:' as a protocol it can handle. If you use IE and LimeWire on Windows, I'm not sure if it works. Please send me feedback on the matter.

Ideally, operating systems would have an integrated P2P client that would enable content to be displayed inline documents. Unfortunantly, even OS X doesn't have the ability for arbitrary protocols to be handled by external handlers and returned inline to the application that requested it.

Notes

• This service used to automatically prefix 'urn:sha1:' to the exactl URI field . It has since been removed to allow this service to refer to files using other URI methods.
• 'openssl sha1' provides the Base16 SHA1. You'll need to convert that into a URN Base32 SHA1 to use it with this service. See sha1-16-32.pl below.
• Any files that are linked to using this service are not hosted here directly. I should not be held liable for any illegal activity done using this service. I have no control what content is linked to using this service. They're just exact URIs and file names, anyways.

Credit

Cortland Klein
pixelcort.com

How it Works

• magnet.cgi (2005/01/06)

  This is what does the redirect service. Spiffy, huh? I'd add a 16-32 converter, but my host doesn't have Convert::Base32 and I don't know how to use a module manually.

  
  #!/usr/bin/env perl
  my @split_path_info = split m{/}, $ENV{'PATH_INFO'};
  shift @split_path_info
  print "Location: \
  magnet:?xt=@split_path_info[0]&dn=@split_path_info[1]";
  

• magnet.sh

  Quick script to generate a magnet link. 'cd' to the directory with the file you want, then 'magnet.sh file' You'll need 'sha1-16-32.pl'.

  
  #!/bin/sh
  echo -n "http://magnet.pixelcort.com/"
  openssl sha1 $1 | cut -f 2 -d " " | sha1-16-32.pl
  echo -n "/"
  echo $1
  

• sha1-16-32.pl (2005/01/06)

  Give it a Base16 SHA1 and it gives you a URN Base32 SHA1.

  
  #!/usr/bin/env perl
  use Convert::Base32;
  $Base32Hash = uc(encode_base32(pack('H40', <STDIN>)));
  print "urn:sha1:", $Base32Hash;