从_Request，_Post和_Get修剪空间的缺点？

Question

Problem

I have an issue on a rather large platform where users can enter data that contains spaces at the beginning and at the end of the input. This causes issues. I know that I can modify the JavaScript validation, but this website has a tremendous amount of pages and forms. Finding and changing each occurrence would be a nightmare.

Workaround

Since all the forms and pages share index.php, I thought of the idea of intercepting the request/get/post variables before any controller/routing processing is handled by the platform.

Note: I am aware that this is an extremely cheap way of going about it. But actions must be taken immediately until I can at least work on doing it the right way. This is functioning perfectly as it is. I just have a couple concerns.

$_REQUEST   = array_map('trim',$_REQUEST);
$_GET       = array_map('trim',$_GET);
$_POST  = array_map('trim',$_POST);

Conerns

1. Are there any actual legitimate scenarios where this code would error on?

2. Is there a major performance hit?

3. Are there any security flaws?

4. Are there risks of data integrity being sabotaged with trim()?

Answer 1

1. I can't think of any. Trim would simply trim leading and trailing spaces of a string. However, it would fail on nested arrays.
2. This, ofcourse affects performance but it's nothing major. Do however note that this is running on each and every single index.php call, even if there was no post data.
3. Trim wouldn't cause security flaws. If you're validating and sanitizing user input in latter pages where you format the data, then there shouldn't be any.
4. I can't answer that question without further knowledge.

If this is only a temporary workaround, then it will do the job. But I wouldn't keep doing this forever and I suggest you fix it field by field when you can.