Move HTTP libs and middleware into ActionDispatch component

1 files changed, 222 insertions, 0 deletions

diff --git a/actionpack/lib/action_dispatch/middleware/session/cookie_store.rb b/actionpack/lib/action_dispatch/middleware/session/cookie_store.rb
new file mode 100644
index 0000000000..293fbca7cf
--- /dev/null
+++ b/actionpack/lib/action_dispatch/middleware/session/cookie_store.rb
@@ -0,0 +1,222 @@
+module ActionDispatch
+  module Session
+    # This cookie-based session store is the Rails default. Sessions typically
+    # contain at most a user_id and flash message; both fit within the 4K cookie
+    # size limit. Cookie-based sessions are dramatically faster than the
+    # alternatives.
+    #
+    # If you have more than 4K of session data or don't want your data to be
+    # visible to the user, pick another session store.
+    #
+    # CookieOverflow is raised if you attempt to store more than 4K of data.
+    #
+    # A message digest is included with the cookie to ensure data integrity:
+    # a user cannot alter his +user_id+ without knowing the secret key
+    # included in the hash. New apps are generated with a pregenerated secret
+    # in config/environment.rb. Set your own for old apps you're upgrading.
+    #
+    # Session options:
+    #
+    # * <tt>:secret</tt>: An application-wide key string or block returning a
+    #   string called per generated digest. The block is called with the
+    #   CGI::Session instance as an argument. It's important that the secret
+    #   is not vulnerable to a dictionary attack. Therefore, you should choose
+    #   a secret consisting of random numbers and letters and more than 30
+    #   characters. Examples:
+    #
+    #     :secret => '449fe2e7daee471bffae2fd8dc02313d'
+    #     :secret => Proc.new { User.current_user.secret_key }
+    #
+    # * <tt>:digest</tt>: The message digest algorithm used to verify session
+    #   integrity defaults to 'SHA1' but may be any digest provided by OpenSSL,
+    #   such as 'MD5', 'RIPEMD160', 'SHA256', etc.
+    #
+    # To generate a secret key for an existing application, run
+    # "rake secret" and set the key in config/environment.rb.
+    #
+    # Note that changing digest or secret invalidates all existing sessions!
+    class CookieStore
+      # Cookies can typically store 4096 bytes.
+      MAX = 4096
+      SECRET_MIN_LENGTH = 30 # characters
+
+      DEFAULT_OPTIONS = {
+        :key          => '_session_id',
+        :domain       => nil,
+        :path         => "/",
+        :expire_after => nil,
+        :httponly     => true
+      }.freeze
+
+      ENV_SESSION_KEY = "rack.session".freeze
+      ENV_SESSION_OPTIONS_KEY = "rack.session.options".freeze
+      HTTP_SET_COOKIE = "Set-Cookie".freeze
+
+      # Raised when storing more than 4K of session data.
+      class CookieOverflow < StandardError; end
+
+      def initialize(app, options = {})
+        # Process legacy CGI options
+        options = options.symbolize_keys
+        if options.has_key?(:session_path)
+          options[:path] = options.delete(:session_path)
+        end
+        if options.has_key?(:session_key)
+          options[:key] = options.delete(:session_key)
+        end
+        if options.has_key?(:session_http_only)
+          options[:httponly] = options.delete(:session_http_only)
+        end
+
+        @app = app
+
+        # The session_key option is required.
+        ensure_session_key(options[:key])
+        @key = options.delete(:key).freeze
+
+        # The secret option is required.
+        ensure_secret_secure(options[:secret])
+        @secret = options.delete(:secret).freeze
+
+        @digest = options.delete(:digest) || 'SHA1'
+        @verifier = verifier_for(@secret, @digest)
+
+        @default_options = DEFAULT_OPTIONS.merge(options).freeze
+
+        freeze
+      end
+
+      def call(env)
+        env[ENV_SESSION_KEY] = AbstractStore::SessionHash.new(self, env)
+        env[ENV_SESSION_OPTIONS_KEY] = @default_options
+
+        status, headers, body = @app.call(env)
+
+        session_data = env[ENV_SESSION_KEY]
+        if !session_data.is_a?(AbstractStore::SessionHash) || session_data.send(:loaded?)
+          session_data = marshal(session_data.to_hash)
+
+          raise CookieOverflow if session_data.size > MAX
+
+          options = env[ENV_SESSION_OPTIONS_KEY]
+          cookie = Hash.new
+          cookie[:value] = session_data
+          unless options[:expire_after].nil?
+            cookie[:expires] = Time.now + options[:expire_after]
+          end
+
+          cookie = build_cookie(@key, cookie.merge(options))
+          case headers[HTTP_SET_COOKIE]
+          when Array
+            headers[HTTP_SET_COOKIE] << cookie
+          when String
+            headers[HTTP_SET_COOKIE] = [headers[HTTP_SET_COOKIE], cookie]
+          when nil
+            headers[HTTP_SET_COOKIE] = cookie
+          end
+        end
+
+        [status, headers, body]
+      end
+
+      private
+        # Should be in Rack::Utils soon
+        def build_cookie(key, value)
+          case value
+          when Hash
+            domain  = "; domain="  + value[:domain] if value[:domain]
+            path    = "; path="    + value[:path]   if value[:path]
+            # According to RFC 2109, we need dashes here.
+            # N.B.: cgi.rb uses spaces...
+            expires = "; expires=" + value[:expires].clone.gmtime.
+              strftime("%a, %d-%b-%Y %H:%M:%S GMT") if value[:expires]
+            secure = "; secure" if value[:secure]
+            httponly = "; httponly" if value[:httponly]
+            value = value[:value]
+          end
+          value = [value] unless Array === value
+          cookie = Rack::Utils.escape(key) + "=" +
+            value.map { |v| Rack::Utils.escape(v) }.join("&") +
+            "#{domain}#{path}#{expires}#{secure}#{httponly}"
+        end
+
+        def load_session(env)
+          request = Rack::Request.new(env)
+          session_data = request.cookies[@key]
+          data = unmarshal(session_data) || persistent_session_id!({})
+          [data[:session_id], data]
+        end
+
+        # Marshal a session hash into safe cookie data. Include an integrity hash.
+        def marshal(session)
+          @verifier.generate(persistent_session_id!(session))
+        end
+
+        # Unmarshal cookie data to a hash and verify its integrity.
+        def unmarshal(cookie)
+          persistent_session_id!(@verifier.verify(cookie)) if cookie
+        rescue ActiveSupport::MessageVerifier::InvalidSignature
+          nil
+        end
+
+        def ensure_session_key(key)
+          if key.blank?
+            raise ArgumentError, 'A key is required to write a ' +
+              'cookie containing the session data. Use ' +
+              'config.action_controller.session = { :key => ' +
+              '"_myapp_session", :secret => "some secret phrase" } in ' +
+              'config/environment.rb'
+          end
+        end
+
+        # To prevent users from using something insecure like "Password" we make sure that the
+        # secret they've provided is at least 30 characters in length.
+        def ensure_secret_secure(secret)
+          # There's no way we can do this check if they've provided a proc for the
+          # secret.
+          return true if secret.is_a?(Proc)
+
+          if secret.blank?
+            raise ArgumentError, "A secret is required to generate an " +
+              "integrity hash for cookie session data. Use " +
+              "config.action_controller.session = { :key => " +
+              "\"_myapp_session\", :secret => \"some secret phrase of at " +
+              "least #{SECRET_MIN_LENGTH} characters\" } " +
+              "in config/environment.rb"
+          end
+
+          if secret.length < SECRET_MIN_LENGTH
+            raise ArgumentError, "Secret should be something secure, " +
+              "like \"#{ActiveSupport::SecureRandom.hex(16)}\".  The value you " +
+              "provided, \"#{secret}\", is shorter than the minimum length " +
+              "of #{SECRET_MIN_LENGTH} characters"
+          end
+        end
+
+        def verifier_for(secret, digest)
+          key = secret.respond_to?(:call) ? secret.call : secret
+          ActiveSupport::MessageVerifier.new(key, digest)
+        end
+
+        def generate_sid
+          ActiveSupport::SecureRandom.hex(16)
+        end
+
+        def persistent_session_id!(data)
+          (data ||= {}).merge!(inject_persistent_session_id(data))
+        end
+
+        def inject_persistent_session_id(data)
+          requires_session_id?(data) ? { :session_id => generate_sid } : {}
+        end
+
+        def requires_session_id?(data)
+          if data
+            data.respond_to?(:key?) && !data.key?(:session_id)
+          else
+            true
+          end
+        end
+    end
+  end
+end