mod_socket_policy_server - An Adobe® Socket Policy Server

mod_socket_policy_server is an Apache™ module for serving Adobe® socket policy files.

Adobe Flash Player (since version 9.0.124.0) will not open a socket connection to a server unless the server first authorizes the connection via an Adobe socket policy. This module serves these policies. (Adobe uses a non-standard protocol for serving these policies, hence the existence of this module.)

Among other applications, the ability to create a listening socket is useful for sending real-time updates to web applications (the server can push data to the listening socket instead of waiting for the client to poll and pull).

Download

Source files and compiled packages are available in the Downloads directory.

Install

On Debian systems:

Download libapache2-mod-socket-policy-server_0.0.8-1_amd64.deb
dpkg -i libapache2-mod-socket-policy-server_0.0.8-1_amd64.deb
If something doesn't work, please let me know!

On other Linux systems:

Download libapache2-mod-socket-policy-server_0.0.8.orig.tar.gz
make
make install
Please note that the module has not been tested on systems other than Debian. If something doesn't work, please let me know!

On Windows:

Download libapache2-mod-socket-policy-server_0.0.8.zip
Copy the contents of the modules directory to your modules directory.
Copy the contents of the configuration files to your configuration file.
Copy a socket policy from the configuration directory to your configuration directory.
Please note that the module has not been tested on systems other than Debian. If something doesn't work, please let me know!

Configure the server

The default configuration is well-commented. You can the find the default configuration in:

/etc/apache2/mods-available/socket-policy-server.conf

Configure Apache2 to listen on port 843.

/etc/apache2/sites-available/socket-policy-server

Set the value of SocketPolicyServer to enable or disable the module for the default VirtualHost.
Set the value of SocketPolicyFile to the default socket policy file for the default VirtualHost.

/etc/apache2/sites-available/...

(Optionally) Create one or more virtual hosts.
Set the value of SocketPolicyServer to enable or disable the module for each virtual host.
Set the value of SocketPolicyFile to enable or disable the module for each virtual host.

Test the server

When using the default configuration on Debian, you can test the installation using:

printf "<policy-file-request/>\0" | netcat 127.0.0.1 843

And the server should respond with the configured socket policy. If the server does not respond as expected:

Check that the module is installed.
Check that the module is loaded.
Check that the server is listening on the desired ip address and port.
Check that the module is enabled for the desired virtual host.
Check that the SocketPolicyFile is configured for the desired virtual host.
Check that the SocketPolicyFile is accessible by the web server.
Setting LogLevel Debug for the Apache2 server and checking the Apache2 logs may be helpful.

Configure the socket policy

Adobe socket policies are configured using XML. A selection of pre-configured socket policies are available in /usr/share/libapache2-mod-socket-policy-server/socket-policy/

permitted-cross-domain-policies-none.xml

Does not allow cross domain policies to be served.
Is the most restrictive socket policy.
Is the default socket policy for this module.

permitted-cross-domain-policies-by-content-type.xml

Allows cross domain policies to be served, but only when the policy is served with Content-Type: text/x-cross-domain-policy

permitted-cross-domain-policies-by-ftp-filename.xml

Allows cross domain policies to be served, but only when the URL ends with /crossdomain.xml

permitted-cross-domain-policies-all.xml

Allows any file to be served as a cross domain policy file.

For more information about socket policies in particular, and cross domain policies in general, refer to the Adobe Cross Domain Policy File Specification.