Merge pull request #21203 from denniss/issue-21199

Authorization scheme should be case insensitive. Fixes #21199

actionpack/lib/action_controller/metal/http_authentication.rb

@@ -94,7 +94,7 @@ def authenticate(request, &login_procedure)
       end
 
       def has_basic_credentials?(request)
-        request.authorization.present? && (auth_scheme(request) == 'Basic')
+        request.authorization.present? && (auth_scheme(request).downcase == 'basic')
       end
 
       def user_name_and_password(request)

actionpack/test/controller/http_basic_authentication_test.rb

@@ -100,6 +100,14 @@ def test_encode_credentials_has_no_newline
     assert_no_match(/\n/, result)
   end
 
+  test "succesful authentication with uppercase authorization scheme" do
+    @request.env['HTTP_AUTHORIZATION'] = "BASIC #{::Base64.encode64("lifo:world")}"
+    get :index
+
+    assert_response :success
+    assert_equal 'Hello Secret', @response.body, 'Authentication failed when authorization scheme BASIC'
+  end
+
   test "authentication request without credential" do
     get :display