I am trying to create an SNI based frontend/backend setup in HAProxy. It seems that ssl_fc_has_sni is always evaluating to 0 in my log and I haven't been able to figure out why.
This is a simplified version of the config I've been testing with:
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 items of note:
haproxy -vv shows OpenSSL library supports SNI : yes haproxy[17807]: frontend:public_ssl be_no_sni/fe_no_sni client_ip:<ip> client_port:42285 SSL_version:- SSL_cypher:- SNI:0 --openssl s_client -servername www.example.com -connect <ip>:443.I feel like I'm missing something obvious since there is no ssl version, cypher, or sni.
Looks like ssl_fc_has_sni is meant to be used post termination. Checking for the existence of the SNI host can be accomplished with:
frontend public_ssl
bind :443
mode tcp
tcp-request inspect-delay 5s
tcp-request content accept if { req_ssl_hello_type 1 }
use_backend be_sni if { req.ssl_sni -m found }
default_backend be_no_sni