Ssl – AWS: Forwarding HTTPS to HTTP via ELB

I would hazard a guess without you posting your ELB configuration that the ELB is redirecting HTTPS (443/tcp) traffic to the EC2 instance on HTTP (80/tcp). Then you're .htaccess and plugin are trying to redirect it back to HTTPS because it is being seen over HTTP.

Go take a look at your EC2 console under Network & Security > Load Balancers and I would imagine you'll see the Port Configuration says something along the lines of 443 forwarding to 80 (HTTPS, Certificate: blah)

In the end, I implemented the requirement of our partner as follows:

• launch an instance in AWS
• allocate and attach an Elastic IP (EIP) to it
• Installed Apache
• (in our case, installed our SSL certificate)
• Configured Apache as a reverse proxy server, forwarding to a CNAME that pointed to our ELB

Here's a sample Apache virtual host configuration. I turned off NameVirtualHost and specified the address of our EIP. I also disabled a default host. If the partner desires, I will add a <Directory> block that accepts requests only from their IP range.

<IfModule mod_ssl.c>
# Catch non-SSL requests and redirect to SSL
<VirtualHost 12.34.567.890:80>
  ServerName our-static-ip-a-record.example.com
  Redirect / https://our-elb-cname.example.com       
</VirtualHost>
# Handle SSL requests on the static IP
<VirtualHost 12.34.567.890:443>
  ServerAdmin monitor@example.com
  ServerName our-static-ip-a-record.example.com

  # SSL Configuration
  SSLEngine on
  SSLProxyEngine on
  SSLProxyCACertificateFile /etc/apache2/ssl/gd_bundle.crt
  SSLCertificateFile    /etc/apache2/ssl/example.com.crt    
  SSLCertificateKeyFile /etc/apache2/ssl/private.key
  # Additional defaults, e.g. ciphers, defined in apache's ssl.conf

  # Where the magic happens
  ProxyPass / https://our-elb-cname.example.com/
  ProxyPassReverse / https://our-elb-cname.example.com/

  # Might want this on; sets X-Forwarded-For and other useful headers
  ProxyVia off

  # This came from an example I found online, handles broken connections from IE
  BrowserMatch "MSIE [2-6]" \
    nokeepalive ssl-unclean-shutdown \
    downgrade-1.0 force-response-1.0
  # MSIE 7 and newer should be able to use keepalive
  BrowserMatch "MSIE [17-9]" ssl-unclean-shutdown
</VirtualHost>
</IfModule>

Hope this saves someone else some time in the future :-)