PHP RFC: Deprecate mb_ereg_replace eval option
- Version: 1.0
- Date: 2016-01-04
- Author: Rouven Weßling, me@rouvenwessling.de
- Status: Implemented (PHP 7.1)
- First Published at: https://wiki.php.net/rfc/deprecate_mb_ereg_replace_eval_option
Introduction
This RFC aims at deprecating the e option that mb_ereg_replace and mb_eregi_replace provide.
Problems
The e option evaluates arbitrary PHP code it can easily be exploited if user input is not carefully validated or sanitized.
Didn't we already do that?
No. Around 4 years ago a RFC was passed to deprecate a similar options in preg_replace. This was executed in PHP 5.5 (deprecation) respectively PHP 7 (removal). That a similar option is present in mb_ereg_replace was apparently overlooked.
Proposal
Emit an E_DEPRECATED error whenever mb_ereg_replace or mb_eregi_replace is called with the e option.
Backward Incompatible Changes
Once the feature is actually removed, any code relying on it will break. Whether silently or with an error will be left to decide in the removal RFC.
The suggested replacement, mb_ereg_replace_callback is has only been available since PHP 5.4.1. Projects which support both PHP 5.3 and PHP 7.1 may need two code paths to avoid deprecation warnings.
There is no mb_eregi_replace_callback function. Code using it will have to be converted to use mb_ereg_replace_callback with the i option.
Future Scope
The removal of this feature is not part of this RFC. This should be done, when a release, where this is possible, is actually on the agenda.
Proposed Voting Choices
Should an E_DEPRECATED error be emitted whenever mb_ereg_replace or mb_eregi_replace is called with the e option?
This vote will require a 50%+1 majority.
Voting opened on January 28th 2016, to close on February 4th.
Patches and Tests
A patch is available: <https://github.com/php/php-src/pull/1994> (merged).