Please help rewrite proper parameter

[shiz]

Hi,

Sometimes, bots are notorious for doing that, arguments are over urlencoded.
 If someone knew a way to rewrite them back to their normal state, that
would be awesome.

e.g.  

Normal URL:  www.site.com/file.php?param=blahblah

URLs that bots try sometimes (often in fact - don't know where they get
those strings BTW):

www.site.com/file.php?param%253Dblahblah
www.site.com/file.php?param%25253Dblahblah
www.site.com/file.php?param%2525253Dblahblah
...

Tried the following in the general filter block, then into the php block,
didn't help:

rewrite ^(.*)(param)\%(25)+(3D)(.*)$ $1$2=$5 redirect;
rewrite ^(.*)(param)=(.*)$ $1$2=$3 redirect;

Thanks!

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,265514,265514#msg-265514