From 825945e7d4bc46de381991909da1253ce5a7f942 Mon Sep 17 00:00:00 2001
From: Prem Sichanugrist <s@sikachu.com>
Date: Sat, 1 Jan 2011 23:51:05 +0700
Subject: [PATCH] Filter sensitive `QUERY_STRING` parameters in the log

This provides more safety to applications that appends secret information, such as API key or SSO token, as a `QUERY_STRING` in the request.

Note that in Ruby 1.8 those `QUERY_STRING` might not be in the same order of original request as we reconstructed the `QUERY_STRING` from `request.GET` parameters and Ruby 1.8 doesn't honor the order of insertion.
---
 .../lib/action_dispatch/http/filter_parameters.rb  |   14 ++++++++++----
 actionpack/test/dispatch/request_test.rb           |   12 ++++++++++++
 railties/lib/rails/rack/logger.rb                  |    2 +-
 3 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/actionpack/lib/action_dispatch/http/filter_parameters.rb b/actionpack/lib/action_dispatch/http/filter_parameters.rb
index 1ab48ae..c20920f 100644
--- a/actionpack/lib/action_dispatch/http/filter_parameters.rb
+++ b/actionpack/lib/action_dispatch/http/filter_parameters.rb
@@ -1,14 +1,15 @@
 require 'active_support/core_ext/object/blank'
 require 'active_support/core_ext/hash/keys'
 require 'active_support/core_ext/object/duplicable'
+require 'active_support/core_ext/object/to_query'
 
 module ActionDispatch
   module Http
     # Allows you to specify sensitive parameters which will be replaced from
-    # the request log by looking in all subhashes of the param hash for keys
-    # to filter. If a block is given, each key and value of the parameter
-    # hash and all subhashes is passed to it, the value or key can be replaced
-    # using String#replace or similar method.
+    # the request log by looking in the query string of the request and all
+    # subhashes of the param hash to filter. If a block is given, each key and
+    # value of the parameter hash and all subhashes is passed to it, the value
+    # or key can be replaced using String#replace or similar method.
     #
     # Examples:
     #
@@ -38,6 +39,11 @@ module ActionDispatch
         @filtered_env ||= env_filter.filter(@env)
       end
 
+      # Reconstructed a path with all sensitive GET parameters replaced.
+      def filtered_path
+        @filtered_path ||= query_string.empty? ? path : "#{path}?#{parameter_filter.filter(self.GET).to_param.gsub(/%5BFILTERED%5D/,'[FILTERED]')}"
+      end
+
     protected
 
       def parameter_filter
diff --git a/actionpack/test/dispatch/request_test.rb b/actionpack/test/dispatch/request_test.rb
index 75b674e..149757c 100644
--- a/actionpack/test/dispatch/request_test.rb
+++ b/actionpack/test/dispatch/request_test.rb
@@ -518,6 +518,18 @@ class RequestTest < ActiveSupport::TestCase
     assert_equal "1", request.params["step"]
   end
 
+  test "filtered_path returns path with filtered query string" do
+    request = stub_request('QUERY_STRING' => "username=sikachu&secret=bd4f21f&api_key=b1bc3b3cd352f68d79d7",
+      'PATH_INFO' => '/authenticate',
+      'action_dispatch.parameter_filter' => [:secret, :api_key])
+
+    path = request.filtered_path
+    assert_match /^\/authenticate\?/, path
+    assert_match /username=sikachu/, path
+    assert_match /secret=\[FILTERED\]/, path
+    assert_match /api_key=\[FILTERED\]/, path
+  end
+
 protected
 
   def stub_request(env = {})
diff --git a/railties/lib/rails/rack/logger.rb b/railties/lib/rails/rack/logger.rb
index 32acc66..3be262d 100644
--- a/railties/lib/rails/rack/logger.rb
+++ b/railties/lib/rails/rack/logger.rb
@@ -19,7 +19,7 @@ module Rails
 
       def before_dispatch(env)
         request = ActionDispatch::Request.new(env)
-        path = request.fullpath
+        path = request.filtered_path
 
         info "\n\nStarted #{request.request_method} \"#{path}\" " \
              "for #{request.ip} at #{Time.now.to_default_s}"
-- 
1.7.3.4