(MODULES-2682) Update Apache Configuration to use FilesMatch instead …

…of AddHandler for PHP Files.

The issue with this is that the extension handling behaviour of apache is
not well known by most php developers, and many php scripts are open to
security issues if this configuration is used (most commonly these scripts
handle upload forms which white list image extensions). For example
foo.php.jpg will be handled by php.

Many distro's no longer use AddHandler in their default config:
  http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/vivid/php5/vivid/view/head:/debian/php5.conf.

The PHP manual also recommends avoiding it:
  http://php.net/manual/en/install.unix.apache2.php#example-20

This is based on Alejandro Bednarik's <alejandro.bednarik@gmail.com> original
fix, I added proper regex escaping, and a changelog entry. All bugs are mine.

CHANGELOG.md

@@ -1,3 +1,14 @@
+## UNRELEASED
+### Summary
+
+TODO
+
+###
+
+#### Security
+
+* apache::mod::php now uses FilesMatch to configure the php handler. This is following the recommended upstream configuration guidelines (http://php.net/manual/en/install.unix.apache2.php#example-20) and distribution's default config (e.g.: http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/vivid/php5/vivid/view/head:/debian/php5.conf). It avoids inadvertently exposing the PHP handler to executing uploads with names like 'file.php.jpg', but might impact setups with unusual requirements.
+
 ## 2015-11-17 - Supported Release 1.7.0
 ### Summary
 This release includes many new features and bugfixes. There are test, documentation and misc improvements.

spec/classes/mod/php_spec.rb

@@ -88,7 +88,7 @@
       let :params do
         { :extensions => ['.php','.php5']}
       end
-      it { is_expected.to contain_file("php5.conf").with_content(/AddHandler php5-script .php .php5\n/) }
+      it { is_expected.to contain_file("php5.conf").with_content(Regexp.new(Regexp.escape('<FilesMatch ".+(\.php|\.php5)$">'))) }
     end
     context "with specific version" do
       let :pre_condition do

templates/mod/php5.conf.erb

@@ -14,8 +14,9 @@
 #
 # Cause the PHP interpreter to handle files with a .php extension.
 #
-AddHandler php5-script <%= @extensions.flatten.compact.join(' ') %>
-AddType text/html .php
+<FilesMatch ".+(<%= @extensions.flatten.compact.collect { |s| Regexp.escape(s) }.join('|') %>)$">
+    SetHandler php5-script
+</FilesMatch>
 
 #
 # Add index.php to the list of files that will be served as directory