logging of tls logons

I have such entries in my radius.log Fri Jun 6 18:52:31 2008 : Auth: Login OK: [asus_large] (from client wifi port 2 cli 00-19-7D-4A-B7-F4) asus_large - in this example is a common name of SSL certificate and I thought it cannot be forged and I can identify which certificate was used. But today I entered to wifi network from my PDA and saw that I can forge this entry as I want. So, it's not really common name, but something provided by client. So, how can I get in logs exactly common names? -- Vladimir Vassiliev <vova@edu.yar.ru>