I used Vacuum-IM to get the xml data using the xml console:
>>>> user1@host.tld/Vacuum-IM 10:58:54 +0 >>>>
<iq type="get" id="sid_134">
<list xmlns="urn:xmpp:archive" with="user2@host.tld">
<set xmlns="http://jabber.org/protocol/rsm">
<max>30</max>
<before/>
</set>
</list>
</iq>
<<<< user1@host.tld/Vacuum-IM 10:58:54 +158 <<<<
<iq type="result" id="sid_134" to="user1@host.tld/Vacuum-IM">
<list xmlns="urn:xmpp:archive">
<chat with="user2@host.tld" start="2014-02-19T07:26:56.826Z"/>
<chat with="user2@host.tld" start="2014-02-19T06:56:22.399Z"/>
<chat with="user2@host.tld" start="2014-02-17T17:38:25.303Z"/>
<chat with="user2@host.tld" start="2014-02-17T17:12:14.058Z"/>
<chat with="user2@host.tld" start="2014-02-20T08:28:37.058Z"/>
<chat with="user2@host.tld" start="2014-02-20T08:05:44.693Z"/>
<chat with="user2@host.tld" start="2014-02-19T13:58:51.830Z"/>
<chat with="user2@host.tld" start="2014-02-19T13:29:19.550Z"/>
<chat with="user2@host.tld" start="2014-02-19T12:22:05.512Z"/>
<chat with="user2@host.tld" start="2014-02-19T11:03:52.681Z"/>
<chat with="user2@host.tld" start="2014-02-19T10:32:17.653Z"/>
<chat with="user2@host.tld" start="2014-02-19T09:49:59.331Z"/>
<chat with="user2@host.tld" start="2014-02-20T09:20:29.824Z"/>
<chat with="user2@host.tld" start="2014-02-20T10:09:59.217Z"/>
<chat with="user2@host.tld" start="2014-02-20T10:27:37.438Z"/>
<chat with="user2@host.tld" start="2014-02-20T10:43:00.381Z"/>
<set xmlns="http://jabber.org/protocol/rsm">
<first index="19">6036</first>
<last>6051</last>
<count>49</count>
</set>
</list>
</iq>
But this output is not correct as there are conversations after 20.02.2014 which are missing in the server reply. They are available using the openfire admin console.