mod_auth_external_insecure

Introduction

Allow client authentication to be handled by an external script/process.

Warning: This module is not currently maintained, and may be buggy and insecure in certain configurations/environments. It is not recommended for production use. Please use one of the many other authentication modules.

Installation

mod_auth_external_insecure depends on a Lua module called lpty. You can install it on many platforms using LuaRocks, for example:

sudo luarocks install lpty

Configuration

As with all auth modules, there is no need to add this to modules_enabled. Simply add in the global section, or for the relevant hosts:

authentication = "external_insecure"

These options are specific to mod_auth_external_insecure:

external_auth_protocol May be “generic” or “ejabberd” (the latter for compatibility with ejabberd external auth scripts. Default is “generic”.
external_auth_command The command/script to execute.

Two other options are also available, depending on whether the module is running in ‘blocking’ or ‘non-blocking’ mode:

external_auth_timeout blocking The number of seconds to wait for a response from the auth process. Default is 5.
external_auth_processes non-blocking The number of concurrent processes to spawn. Default is 1, increase to handle high connection rates efficiently.

Blocking vs non-blocking

Non-blocking mode is experimental and is disabled by default.

Enable at your own risk if you fulfil these conditions:

external_auth_blocking = false;

Protocol

Prosody executes the given command/script, and sends it queries.

Your auth script should simply read a line from standard input, and write the result to standard output. It must do this in a loop, until there’s nothing left to read. Prosody can keep sending more lines to the script, with a command on each line.

Each command is one line, and the response is expected to be a single line containing “0” for failure or “1” for success. Your script must respond with “0” for anything it doesn’t understand.

There are three commands used at the moment:

auth

Check if a user’s password is valid.

Example: auth:username:example.com:abc123

Note: The password can contain colons. Make sure to handle that.

isuser

Check if a user exists.

Example: isuser:username:example.com

setpass

Set a new password for the user. Implementing this is optional.

Example: setpass:username:example.com:abc123

Note: The password can contain colons. Make sure to handle that.

ejabberd compatibility

ejabberd implements a similar protocol. The main difference is that Prosody’s protocol is line-based, while ejabberd’s is length-prefixed.

Add this to your config if you need to use an ejabberd auth script:

    external_auth_protocol = "ejabberd"

Compatibility

0.8 Works
0.9 Works