How to re-write %3f to ? in apache - apache

Question

Most of our pages are accessed by query string, so our URLs look like this:
http://www.example.com/?var=val&var2=val2
I found that somewhere on the web, someone has linked back to us with links like this:
http://www.example.com/%3Fvar%3Dval%26var2%3Dval2
I found a large block of code to add to my .htaccess file, but it REALLY slowed down my page requests. What I'd like is to just catch that "%" at the beginning of the filename and redirect it to a php file where I can parse it into a query string and 301 redirect it.
I have a feeling that if I knew what I was doing this would actually be a pretty easy thing. Let's presume that my php file will be called percent_fix.php
(I am sure I can write the php, I just need help with the .htaccess rewrite condition and rule.)

Answer 1

Try to give your default page to your links. e.g. index.php
Then add to your .htaccess
# for %3f ...
RewriteRule ^/index.php\?(.*)$ /index.php?$1

Answer 2

You are almost certainly getting a 403 error.
The error is caused because ? is a banned file/directory name character on Windows and Linux. This means when Apache attempts to find a file or directory named "/document/root/index.php?blah" (after decoding) and it causes a 403 error. This is before the .htaccess files are read so you cannot use mod_rewrite in the .htaccess file to override this 403 error or an ErrorDocument defined in the .htaccess file to catch this error.
The only way to catch %3f is to use mod_rewrite or an ErrorDocument in a "VirtualHost" e.g. in httpd-vhosts.conf (or the main server configuration if there aren't any "Virtualhost"s e.g. in httpd.conf).

Answer 3

try the following in your .htaccess file:
RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php$1 [L,NC]

Answer 4

I went back to the link I included in my question, and realized that the simple case near the top of that thread actually does what I need.
Here's what actually work for me:
#in .htaccess
RewriteEngine on
# If an encoded "?" is present in the requested URI, and no unencoded "?" is
# present, then externally redirect to replace the encoded "?" character.
RewriteCond %{THE_REQUEST} ^[A-Z]+\ /([^?\ ]+)\ HTTP/
RewriteCond %1 ^(([^%]*(\%(25)*([^3].|.[^F]))*)*)\%(25)*3F(.*)$ [NC]
RewriteRule ^. http://www.example.com/percent_fix.php?%7 [NE,R=301,L]
Then in percent_fix.php
<?php
if($_SERVER['QUERY_STRING'])
{
$new_query=urldecode($_SERVER['QUERY_STRING']);
header('HTTP/1.1 301 Moved Permanently');
header('Location: http://www.example.com/?'.$new_query);
die();
}
else
{
header('HTTP/1.x 404 Not Found');
//readfile("http://www.example.com/?page=404_error");
die();
}
?>