Check user access status in API for current_user

lib/api/helpers.rb

@@ -8,6 +8,11 @@ module API
     def current_user
       private_token = (params[PRIVATE_TOKEN_PARAM] || env[PRIVATE_TOKEN_HEADER]).to_s
       @current_user ||= User.find_by(authentication_token: private_token)
+
+      unless @current_user && Gitlab::UserAccess.allowed?(@current_user)
+        return nil
+      end
+
       identifier = sudo_identifier()
 
       # If the sudo is the current user do nothing

spec/requests/api/api_helpers_spec.rb

@@ -44,6 +44,11 @@ describe API, api: true do
       current_user.should be_nil
     end
 
+    it "should return nil for a user without access" do
+      Gitlab::UserAccess.stub(allowed?: false)
+      current_user.should be_nil
+    end
+
     it "should leave user as is when sudo not specified" do
       env[API::APIHelpers::PRIVATE_TOKEN_HEADER] = user.private_token
       current_user.should == user