Reimplement auth scheme fix

 * Add Rack::Auth.add_scheme to enable folks to fix anything that breaks
 * Add common auth schemes, MS ones, AWS ones, etc are missing, as unlikely
 * Checked Rails - they don't use our authorization code
 * Checked Warden - uses rails
 * Checked Omniauth - uses rails
 * Checked doorkeeper - users rails
 * Checked rack-authentication - does it's own thing
 * Checked warden-oauth - doesn't do headers
 * Checked devise - uses rails
 * Checked oauth2-rack - header creation only
 * Checked rack-oauth2-server - does it's own thing
 * Probably missed a bunch, but that'll have to do

lib/rack.rb

@@ -73,6 +73,18 @@ 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

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

test/spec_auth.rb

@@ -0,0 +1,57 @@
+require 'rack'
+
+describe Rack::Auth do
+  it "should have all common authentication schemes" do
+    Rack::Auth.schemes.should.include? 'basic'
+    Rack::Auth.schemes.should.include? 'digest'
+    Rack::Auth.schemes.should.include? 'bearer'
+    Rack::Auth.schemes.should.include? 'token'
+  end
+
+  it "should allow registration of new auth schemes" do
+    Rack::Auth.schemes.should.not.include "test"
+    Rack::Auth.add_scheme "test"
+    Rack::Auth.schemes.should.include "test"
+  end
+end
+
+describe Rack::Auth::AbstractRequest do
+  it "should symbolize known auth schemes" do
+    env = Rack::MockRequest.env_for('/')
+    env['HTTP_AUTHORIZATION'] = 'Basic aXJyZXNwb25zaWJsZQ=='
+    req = Rack::Auth::AbstractRequest.new(env)
+    req.scheme.should == :basic
+
+
+    env['HTTP_AUTHORIZATION'] = 'Digest aXJyZXNwb25zaWJsZQ=='
+    req = Rack::Auth::AbstractRequest.new(env)
+    req.scheme.should == :digest
+
+    env['HTTP_AUTHORIZATION'] = 'Bearer aXJyZXNwb25zaWJsZQ=='
+    req = Rack::Auth::AbstractRequest.new(env)
+    req.scheme.should == :bearer
+
+    env['HTTP_AUTHORIZATION'] = 'MAC aXJyZXNwb25zaWJsZQ=='
+    req = Rack::Auth::AbstractRequest.new(env)
+    req.scheme.should == :mac
+
+    env['HTTP_AUTHORIZATION'] = 'Token aXJyZXNwb25zaWJsZQ=='
+    req = Rack::Auth::AbstractRequest.new(env)
+    req.scheme.should == :token
+
+    env['HTTP_AUTHORIZATION'] = 'OAuth aXJyZXNwb25zaWJsZQ=='
+    req = Rack::Auth::AbstractRequest.new(env)
+    req.scheme.should == :oauth
+
+    env['HTTP_AUTHORIZATION'] = 'OAuth2 aXJyZXNwb25zaWJsZQ=='
+    req = Rack::Auth::AbstractRequest.new(env)
+    req.scheme.should == :oauth2
+  end
+
+  it "should not symbolize unknown auth schemes" do
+    env = Rack::MockRequest.env_for('/')
+    env['HTTP_AUTHORIZATION'] = 'magic aXJyZXNwb25zaWJsZQ=='
+    req = Rack::Auth::AbstractRequest.new(env)
+    req.scheme.should == "magic"
+  end
+end