I have a Java application that needs to talk to another intranet website using HTTPS in both directions. After fighting with Java's SSL implementations for some time, I gave up on that, and have now set up an Apache that's supposed to act as a bidirectional reverse proxy:
external app ---(HTTPS request)---> Apache ---(local HTTP request)---> Java app
This direction works just fine, however the other direction does not:
Java app ---(local HTTP request)---> Apache ---(HTTPS request)---> external app
This is the configuration for the vhost implementing the second proxy:
Listen 127.0.0.1:8081
<VirtualHost appgateway:8081>
ServerName appgateway.local
SSLProxyEngine on
ProxyPass / https://externalapp.corp:443/
ProxyPassReverse / https://externalapp.corp:443/
ProxyRequests
Off
AllowEncodedSlashes On
# we do not need to apply any more restrictions here, because we listened on
# local connections only in the first place (see the Listen directive above)
<Proxy https://externalapp.corp:443/*>
Order deny,allow
Allow from all
</Proxy>
</VirtualHost>
A curl http://127.0.0.1:8081/ should serve the equivalent of https://externalapp.corp, but instead results in 403 Forbidden, with the following message in the Apache error log:
[Wed Jun 04 08:57:19 2014] [error] [client 127.0.0.1] Directory index forbidden by Options directive: /srv/www/htdocs/
This message completely puzzles me: Yes, I have not set up any permissions on the DocumentRoot of this vhost, but everything works fine for the other proxy direction where I haven't. For reference, here's the other vhost:
Listen this_vm_hostname:443
<VirtualHost javaapp:443>
ServerName javaapp.corp
SSLEngine on
SSLProxyEngine on
# not shown: SSLCipherSuite, SSLCertificateFile, SSLCertificateKeyFile
SSLOptions +StdEnvVars
ProxyPass / http://localhost:8080/
ProxyPassReverse / http://localhost:8080/
ProxyRequests
Off
AllowEncodedSlashes On
# Local reverse proxy authorization override
<Proxy http://localhost:8080/*>
Order deny,allow
Allow from all
</Proxy>
</VirtualHost>
