Merge branch 'cookie_session'

Conflicts:

	lib/camping/ar/session.rb

lib/camping/session.rb

@@ -0,0 +1,70 @@
+# == About camping/session.rb
+#
+# This file contains two modules which supply basic sessioning to your Camping app.
+# Again, we're dealing with a pretty little bit of code: approx. 60 lines.
+# 
+# * Camping::Models::Session is a module which adds a single <tt>sessions</tt> table
+#   to your database.
+# * Camping::Session is a module which you will mix into your application (or into
+#   specific controllers which require sessions) to supply a <tt>@state</tt> variable
+#   you can use in controllers and views.
+#
+# For a basic tutorial, see the *Getting Started* section of the Camping::Session module.
+#require 'camping'
+require 'base64'
+require 'digest/sha2'
+
+module Camping
+# The Camping::Session module is designed to be mixed into your application or into specific
+# controllers which require sessions.  This module defines a <tt>service</tt> method which
+# intercepts all requests handed to those controllers.
+#
+# == Getting Started
+#
+# To get sessions working for your application:
+#
+# 1. <tt>require 'camping/session'</tt>
+# 2. Mixin the module: <tt>module YourApp; include Camping::Session end</tt>
+# 3. Define a secret (and keep it secret): <tt>module YourApp; @@state_secret = "SECRET!"; end</tt>
+# 4. Throughout your application, use the <tt>@state</tt> var like a hash to store your application's data. 
+#
+# == A Few Notes
+#
+# * The session is stored in a cookie. Look in <tt>@cookies.identity</tt>.
+# * Session data is only saved if it has changed. 
+module Session
+    # This <tt>service</tt> method, when mixed into controllers, intercepts requests
+    # and wraps them with code to start and close the session.  If a session isn't found
+    # in the cookie it is created.  The <tt>@state</tt> variable is set and if it changes,
+    # it is saved back into the cookie.
+    def service(*a)
+      if @cookies.identity
+        blob, secure_hash = @cookies.identity.to_s.split(':', 2)
+        blob = Base64.decode64(blob)
+        data = Marshal.restore(blob)
+        data = {} unless secure_blob_hasher(blob).strip == secure_hash.strip
+      else
+        blob = ''
+        data = {}
+      end
+
+      app = self.class.name.gsub(/^(\w+)::.+$/, '\1')
+      @state = (data[app] ||= Camping::H[])
+      hash_before = blob.hash
+      return super(*a)
+    ensure
+      data[app] = @state
+      blob = Marshal.dump(data)
+      unless hash_before == blob.hash
+        secure_hash = secure_blob_hasher(blob)
+        content = Base64.encode64(blob).gsub("\n", '').strip + ':' + secure_hash
+        raise "The session contains to much data" if content.length > 4096
+        @response.set_cookie("identity", content)
+      end
+    end
+
+    def secure_blob_hasher(data)
+      Digest::SHA256.hexdigest(self.class.module_eval('@@state_secret') + data)
+    end
+end
+end