Re: BUG in Regex++ 3.31

From: Yaroslav Govorunov (yg-boost-users_at_[hidden])
Date: 2002-09-09 07:37:34

Hello, John!
You wrote  on Mon, 9 Sep 2002 12:09:37 +0100:

 JM> anything that contains (.*)* is going to get pathological: it's the
 JM> classic test case that breaks all backtracking regex implementations. 
 JM> I hope that a future version will detect and throw and exception when
 JM> something like this is used.

I hope so. But now we have added timer to the regex_match algorithm, so now it throws exception on timeout. This slows down algorithm, but we need this protection. Also I have found that older versions of Regex++ don't have this vulnerability.
Maybe there is a way to find if regular expression contains nested repeats on creation stage?


With best regards, Yaroslav Govorunov,
E-mail: slov_at_[hidden]
http://www.rsdn.ru http://www.isapirewrite.com