Haproxy sni ssl_fc_has_sni always 0

I am trying to create SNI based frontend / backend setup in HAProxy. It seems like ssl_fc_has_sni always evaluates to 0 in my log and I couldn't figure out why.

This is a simplified version of the config I tested:

global
  user haproxy
  group haproxy
  daemon
  log /dev/log local0

defaults
  timeout connect 5s
  timeout client 30s
  timeout server 30s
  timeout tunnel 1h
  log-format frontend:%f\ %b/%s\ client_ip:%Ci\ client_port:%Cp\ SSL_version:%sslv\ SSL_cypher:%sslc\ SNI:%[ssl_fc_has_sni]\ %ts

frontend public_ssl
  bind :443
  log global
  tcp-request inspect-delay 5s
  tcp-request content accept if { req_ssl_hello_type 1 }

  use_backend be_sni if { ssl_fc_has_sni }
  default_backend be_no_sni

backend be_sni
  server fe_sni 127.0.0.1:10444 weight 1 send-proxy

frontend fe_sni
  #terminate with a cert that matches the sni host
  bind 127.0.0.1:10444 ssl crt /mycertdir/certs accept-proxy no-sslv3
  default_backend be_default

frontend fe_no_sni
  #terminate with a generic cert
  bind 127.0.0.1:10443 ssl crt /myothercertdir/default_pub_keys.pem accept-proxy no-sslv3
  default_backend be_default

# backend for when sni does not exist, or ssl term needs to happen on the edge
backend be_no_sni
  server fe_no_sni 127.0.0.1:10443 weight 1 send-proxy

backend be_default
  mode http
  option forwardfor
  option http-pretend-keepalive
  server the_backend 127.0.0.1:8080

      

        
        
        
      

    

Other Notes:

• haproxy -vv
  
  shows that the OpenSSL library supports SNI: yes
• I am running haproxy version 1.5.9 on Fedora 20 via vagrant
• the log always shows SNI: 0 haproxy[17807]: frontend:public_ssl be_no_sni/fe_no_sni client_ip:<ip> client_port:42285 SSL_version:- SSL_cypher:- SNI:0 --
  
  
• I am testing openssl s_client -servername www.example.com -connect <ip>:443
  
  .

I feel like I am missing something obvious as there is no ssl version, cypher or sni.