Re: [VOTE] Timing attack safe string comparison function

From: Date: Thu, 06 Feb 2014 04:31:17 +0000
Subject: Re: [VOTE] Timing attack safe string comparison function
References: 1 2 3 4 5 6 7 8 9  Groups: php.internals 
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On Thu, Feb 6, 2014 at 1:20 PM, Yasuo Ohgaki <[email protected]> wrote:

> Since comparison of short and/or not hashed data (e.g. user supplied raw
> password) should
> not be done as the function name imply, we may better to document so that
> users always
> compare hashed values even when they store raw password/etc.
> So randomized delay may be overkill.
>

Because user should not pass other than hashed values, we may
return FALSE simply when length mismatches. Generated hashed
length should not be a secret. This get rid of length leak issue and
the function name is good for this purpose and make the operation
always constant.

Regards,

--
Yasuo Ohgaki
[email protected]


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