Stuff

<?php
$xmlstr = <<< XMLSTR
<?xml version="1.0"?>
<searchResponse requestID="304">
    <searchResultEntry dn="beapbeapbeap" requestID="304">
        <attr name="proxyAddresses">barbarbar</attr>
        <attr name="objectCategory">foofoofoofoo</attr>
    </searchResultEntry>
</searchResponse>
XMLSTR;
$xml = new SimpleXMLElement($xmlstr);

foreach ($xml->xpath('//attr[@name="proxyAddresses"]') as $c) { var_dump($c['name']); }