Re: little request :)
| From: | Lester Caine | Date: | Thu, 06 Feb 2014 05:49:59 +0000 |
| Subject: | Re: little request :) | ||
| References: | 1 2 3 4 | Groups: | php.internals |
| Request: | Send a blank email to internals+get-72321@lists.php.net to get a copy of this message | ||
Rouven Weßling wrote:
Another one of my silly questions ... What exactly are we trying to protect against? As I understand it, the 'timing attack' is measuring the time it takes to get a response form a login attempt? It is then using the time to make assumptions about valid and invalid user names? So having got what it thinks is a valid name it can then target an attack for the password? My own accesses to this information are direct to a database query so none of the comparisons you are looking at affect me, but at the PHP level I add delays based on previous failures, so three attempts at a login give a longer delay. One protects against the password attack rather than worrying too much about if the user name is valid? In most cases a public email address is also the user name anyway? -- Lester Caine - G8HFL ----------------------------- Contact - http://lsces.co.uk/wiki/?page=contact L.S.Caine Electronic Services - http://lsces.co.uk EnquirySolve - http://enquirysolve.com/ Model Engineers Digital Workshop - http://medw.co.uk Rainbow Digital Media - http://rainbowdigitalmedia.co.ukHiding a string length is really tricky, and only possible to a morelimited extent than hiding byte value differences. That's probably a good conclusion. I think we should just document this as potentially leaking information about the length. If we do find ways to reduce this, by all means, we should take them.