<div dir="ltr">Thanks Arend and Jouni for clarifying. <div><br></div><div>I do use an sqlite database connection to do this on the server! <div><br></div><div>Khali</div></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">
On Mon, Aug 11, 2014 at 11:38 PM, Jouni Malinen <span dir="ltr"><<a href="mailto:j@w1.fi" target="_blank">j@w1.fi</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class="">On Mon, Aug 11, 2014 at 11:27:23AM +0300, khali singh wrote:<br>
> I use global variables at the top of the .C file containing my new EAP<br>
> method. Is it possible that two connecting clients can write to each others<br>
> data?<br>
<br>
</div>Yes. I would strongly discourage such design.<br>
<div class=""><br>
> For example the C file contains a variable called as a global variable<br>
> u8 sessid[17];<br>
><br>
> Can two simultaneous clients cause a problem?<br>
<br>
</div>Yes. There is a reason why every EAP method implementation in hostap.git<br>
uses struct eap_*_data for per-session data.. There can be multiple<br>
concurrent instances of an EAP server method. While there is only a<br>
single thread running, that won't protect against this type of uses of<br>
global variables with multiple users being able to try to authenticate<br>
at the same time.<br>
<br>
That said, it should be noted that the EAP server methods do not have<br>
support for fast session resumption in a similar way to the EAP peer<br>
methods since they do not maintain any internal state between EAP<br>
sessions. The existing examples use either the TLS library to do this<br>
(EAP-TTLS/PEAP/TLS) or a separate component (EAP-SIM/AKA/AKA' and<br>
eap_sim_db). The latter would likely be closer to what you are<br>
describing here.<br>
<span class="HOEnZb"><font color="#888888"><br>
--<br>
Jouni Malinen PGP id EFC895FA<br>
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