[Nginx&TLS] How to make log show a successful exchange of digital certificates.

Tue Feb 5 07:15:04 UTC 2013

Hello,
 I've make nginx support TLS(Mutual Authentication), It's can be work
and very cool. but i want have some detail log about exchange of digital
certificates. for example, the log have exchange success and client digital
certificates information in this exchange action.
 My system like: Broswer <--TLS--> Nginx 1.0.8 <--HTTP--> Tomcat
 So, what can i do? 
 Thanks for your work.
=============== nginx.conf ================
 server
 {
 listen 8889;
 server_name 192.168.10.251;
 index index.jsp index.html index.htm;
 charset utf-8;
 log_format tls_log '$remote_addr $remote_user [$time_local] "$request"
$http_host '
 '$status $upstream_status $body_bytes_sent "$http_referer"
'
 '"$http_user_agent" $ssl_protocol $ssl_cipher
$upstream_addr '
 '$request_time $upstream_response_time'; 
 access_log /usr/local/nginx/logs/http_8889_access.log tls_log;
 #TLS start
 ssl on;
 ssl_certificate ssl/server.crt;
 ssl_certificate_key ssl/server.key;
 ssl_client_certificate ssl/ca.crt ;
 ssl_verify_client on;
 ssl_protocols SSLv2 SSLv3 TLSv1;
 #TLS end
 #chunkin for XTOM
 chunkin on;
 error_page 411 = @my_411_error;
 location @my_411_error {
 chunkin_resume;
 }
 location ~ /mux-.+ {
 proxy_pass http://192.168.10.123:8080;
 proxy_redirect default;
 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
 proxy_set_header X-Real-IP $remote_addr;
 proxy_set_header Host $http_host;
 }
 } 
===========
Posted at Nginx Forum: http://forum.nginx.org/read.php?2,235909,235909#msg-235909