Rack::Auth::AbstractRequest#scheme returns strings

 * This is a breaking API change, but doesn't appear to be used in public

lib/rack.rb

@@ -73,18 +73,6 @@ module Digest
       autoload :Params, "rack/auth/digest/params"
       autoload :Request, "rack/auth/digest/request"
     end
-
-    # Not all of the following schemes are "standards", but they are used often.
-    @schemes = %w[basic digest bearer mac token oauth oauth2]
-
-    def self.add_scheme scheme
-      @schemes << scheme
-      @schemes.uniq!
-    end
-
-    def self.schemes
-      @schemes.dup
-    end
   end
 
   module Session

lib/rack/auth/abstract/request.rb

@@ -21,11 +21,7 @@ def parts
       end
 
       def scheme
-        @scheme ||=
-          begin
-            s = parts.first.downcase
-            Rack::Auth.schemes.include?(s) ? s.to_sym : s
-          end
+        @scheme ||= parts.first.downcase
       end
 
       def params

lib/rack/auth/basic.rb

@@ -41,7 +41,7 @@ def valid?(auth)
 
       class Request < Auth::AbstractRequest
         def basic?
-          !parts.first.nil? && :basic == scheme
+          !parts.first.nil? && "basic" == scheme
         end
 
         def credentials

lib/rack/auth/digest/request.rb

@@ -11,7 +11,7 @@ def method
         end
 
         def digest?
-          :digest == scheme
+          "digest" == scheme
         end
 
         def correct_uri?