https is not working behind haproxy - https

Question

I have to put haproxy in front of my already running Apache web-server. Both haproxy and apache web-server are on separate Cent-OS6.4 machines.
I had installed haproxy-1.5-dev19.el6.x86_64 and it is working fine with http, but getting
below error with https:-
"502 Bad Gateway: The server returned an invalid or incomplete response".
haproxy logs are shown below:
Nov 7 05:49:56 localhost haproxy[9925]: XX.XX.XXX.XX:51949
[07/Nov/2013:05:49:55.204] https-in~ abc-https/server1
1595/0/1/-1/1597 502 714 - - PHNN 2/2/0/0/0 0/0 "GET / HTTP/1.1"
Nov 7 05:49:57 localhost haproxy[9925]: XX.XX.XXX.XX:51947
[07/Nov/2013:05:49:55.972] https-in~ abc-https/server1
1523/0/1/-1/1525 502 714 - - PHNN 1/1/0/0/0 0/0 "GET /favicon.ico HTTP/1.1"
SSL logs on webserver (request behind proxy):
10.0.0.218 - - [06/Nov/2013:22:42:34 -0800] **"GET /"** 400 510
10.0.0.218 - - [06/Nov/2013:22:42:34 -0800] "GET /" 400 510
SSL logs on webserver (direct request):
XX.XX.XX.XX - - [06/Nov/2013:22:48:42 -0800] **"GET / HTTP/1.1"** 200 19553
As you can see the difference between proxy and without proxy at webserver.
Below is my haproxy.cfg file:
global
log 127.0.0.1 local2
chroot /var/lib/haproxy
pidfile /var/run/haproxy.pid
maxconn 40000
user haproxy
group haproxy
daemon
stats socket /var/lib/haproxy/stats
defaults
mode http
log global
option httplog
option dontlognull
option http-server-close
option forwardfor
option redispatch
retries 10
timeout http-request 60s
timeout queue 60s
timeout connect 60s
timeout client 60s
timeout server 60s
timeout http-keep-alive 60s
timeout check 60s
maxconn 30000
Listen stats 0.0.0.:8880
stats enable
stats hide-version
stats uri /
Stats realm HAProxy\ Statistics
stats auth XXXXX:XXXXX
frontend http-in
bind *:80
acl url_static path_beg -i /static /images /javascript /stylesheets
acl url_static path_end -i .jpg .gif .png .css .js
tcp-request connection accept if { src -f /etc/haproxy/whitelist.lst }
tcp-request connection reject if { src_conn_cur ge 200 } tcp-request
connection track-sc1 src
use_backend http-in-static if url_static
default_backend http-in-bk
frontend https-in
bind *:443 ssl crt /home/ec2-user/ev/haproxy.pem
http-request add-header X-Proto https if { ssl_fc }
use_backend abc-https if {ssl_fc}
backend abc-https
server server1 10.0.0.16:443 check
backend http-in-static
server static 10.0.0.16:80 check inter 100 weight 1
backend http-in-bk
acl abuse src_http_err_rate(http-in) ge 100
acl flag_abuser src_inc_gpc0(http-in)
tcp-request content reject if abuse flag_abuser
server server1 10.0.0.16:80 check inter 100 weight 1
There is only one webserver which is already running and I have to implement haproxy in front of that.
Where I am doing wrong? Kindly help me to resolve this issue.
Regards,
Komal Pal

Answer 1

You are decrypting the SSL traffic and then sending the plaintext HTTP to an HTTPS socket on your webserver.
In this setup you would normally send it to port 80 on the webserver, because you have already decrypted it.
If you want to re-encrypt you must change your "server xxx" line to have the flag "ssl" on it as well.