My log format

log_format tls_log '$remote_addr $remote_user [$time_local] "$request" $http_host '
'$status $upstream_status $body_bytes_sent "$http_referer" '
'"$http_user_agent" $upstream_addr [$request_time/$upstream_response_time] '
'[SSL]: $ssl_protocol $ssl_cipher SSL_CLIENT{Verify:$ssl_client_verify, Serial:$ssl_client_serial, SDN:$ssl_client_s_dn, IDN:$ssl_client_i_dn}';


and, thank your work.
nginx is very cool.