Apache 2.4 Reverse Proxy SSL Issue
<p>I am attempting to create the following setup using Apache:</p>

<pre><code>UserBrowser ----Client Certificate---&gt; LoadBalancer (Apache 2.4)
then
LoadBalancer (Apache 2.4) ----LB Client Certificate ----&gt; Apache 2.2 Web Server 
</code></pre>

<p>So the user connects to the load balancer and provides a client certificate - This works correctly.</p>

<p>A Reverse Proxy then makes the Load Balancer connect to the web server, the webserver requests a certificate from the Load Balancer and I get the following error:</p>

<pre><code>Proxy client certificate callback: (0.0.0.0:443) entered
Proxy client certificate callback: (0.0.0.0:443) downstream server wanted client certificate but none are configured
[remote 0.0.0.1:443] SSL Proxy connect failed
[ssl:info] SSL Library Error: error:14094410:SSL routines:SSL3_READ_BYTES:sslv3 alert handshake failure (SSL alert number 40)
[ssl:info] [remote 0.0.0.1:443] Connection closed to child 0 with abortive shutdown (server 0.0.0.0:443)
[ssl:info] [remote 0.0.0.1:443] SSL handshake failed: sending 502
</code></pre>

<p>Load Balancer Config:</p>

<pre><code>SSLProxyEngine on
ProxyRequests off
ProxyPreserveHost on
Proxytimeout 600

SSLProxyCheckPeerCN off
SSLProxyCheckPeerName off

SSLProxyMachineCertificateFile "/path/to/keyandcert.pem"
</code></pre>

<p>Web Server Config:</p>

<pre><code>SSLVerifyClient require
</code></pre>

<p>This scenario works if I remove SSLVerifyClient from the Web Server, traffic is then loadbalanced. I need to have client verification between the User - LB and between the LB - WS.</p>

<p>Keys + Certs have been generated using 1024 bit long modulus</p>

<p>Can anyone offer an insight into what might be going wrong here?</p>