“Error bad URI” when trying to get WEBrick to accept HTTPS

问题

So I've got a simple Sinatra site:

# app.rb         
require 'sinatra'

get '/' do       
  'Hello world!' 
end

And I can set up rack to serve it over HTTP:

# config.ru              
require './app'          
run Sinatra::Application 

# vim: ft=ruby

And it works fine when I browse to http://localhost:9292:

% rackup
[2013-01-22 10:27:52] INFO  WEBrick 1.3.1
[2013-01-22 10:27:52] INFO  ruby 1.9.2 (2011-02-18) [x86_64-darwin10.7.4]
[2013-01-22 10:27:52] INFO  WEBrick::HTTPServer#start: pid=7525 port=9292
127.0.0.1 - - [22/Jan/2013 10:28:05] "GET / HTTP/1.1" 200 12 0.0177            
127.0.0.1 - - [22/Jan/2013 10:28:06] "GET /favicon.ico HTTP/1.1" 404 447 0.0007

I've generated a self-signed certificate, and after some googling, thought I found a way of setting up my rack file to use the cert and serve HTTPS:

# config.ru                                                                     
require './app'                                                                 
require 'webrick'                                                               

Rack::Server.start(                                                             
  :Port             => 9292,                                                    
  :Logger           => WEBrick::Log::new($stderr, WEBrick::Log::DEBUG),         
  :app              => Sinatra::Application,                                    
  :SSLEnable        => true,                                                    
  :SSLVerifyClient  => OpenSSL::SSL::VERIFY_NONE,                               
  :SSLPrivateKey    => OpenSSL::PKey::RSA.new( File.read "server.key" ),        
  :SSLCertificate   => OpenSSL::X509::Certificate.new( File.read "server.crt" ),
  :SSLCertName      => [["CN", WEBrick::Utils::getservername]]                  
)                                                                               

# vim: ft=ruby

But when I visit https://localhost:9292 I get Error code: ssl_error_rx_record_too_long and webrick is ... unhappy:

% rackup
[2013-01-22 10:46:28] DEBUG TCPServer.new(0.0.0.0, 9292)
[2013-01-22 10:46:28] DEBUG TCPServer.new(::, 9292)
[2013-01-22 10:46:28] DEBUG Rack::Handler::WEBrick is mounted on /.
[2013-01-22 10:46:28] INFO  WEBrick::HTTPServer#start: pid=7660 port=9292
[2013-01-22 10:46:33] DEBUG accept: 127.0.0.1:62185
[2013-01-22 10:46:33] ERROR bad URI `?w~Rx03I?\x06?\x00\x00H\x00??'.
localhost - - [22/Jan/2013:10:46:33 EST] "\x16\x03\x01\x00?\x01\x00\x00?\x03\x01P??Y?KOƛ\x0Ew/yO;P\x1E\x13 ?w~Rx03I?\x06?\x00\x00H\x00??" 400 316
- -> ?w~Rx03I?\x06?\x00\x00H\x00??
[2013-01-22 10:46:33] DEBUG close: 127.0.0.1:62185

Feel free to try it yourself, all the files you need to run it (config.ru, app.rb, server.crt, server.key) are in this gist.

So I'm obviously doing something wrong. How can I fix it?