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falooda_281506's avatar
falooda_281506
Icon for Nimbostratus rankNimbostratus
Feb 22, 2017

iRULE difference between strong tolower

What is the difference between both iRule usuage, and when is best to use this:   elseif {[HTTP::uri] contains "/testweb/" {pool TESTweb}   elseif {[string tolower [HTTP::uri]] contains "/testw...
BIG-IP
iRules
security
Kai_Wilke's avatar
Kai_Wilke
Icon for MVP rankMVP
Feb 22, 2017

Hi falooda,

the 

[string tolower [HTTP::uri]]
syntax is the recommended approach, if a human is intended to type the URL into the address bar. In addition, this command is also recommended if you implement certain security controls (e.g. blacklists) and you want to make sure that a different /CaSE can not be used to bypass the policy...

The user/attacker may enter:

https://www.domain.de/shorturl
https://www.domain.de/Shorturl
https://www.domain.de/ShortUrl
https://www.domain.de/SHORTURL

Your first iRule snippet will trigger only on the first example. And your second iRule snippet will trigger in any of the above URL examples.

Cheers, Kai