Burp Extender

Burp Extender allows third-party developers to extend the functionality of Burp Suite. Extensions can read and modify Burp's runtime data and configuration, initiate key actions, and extend Burp's user interface.

Burp is extensible via the IBurpExtender and other interfaces, which are defined below:

IBurpExtender: code Javadoc
IBurpExtenderCallbacks: code Javadoc
IHttpRequestResponse code Javadoc
IScanIssue code Javadoc
IScanQueueItem code Javadoc
IMenuItemHander code Javadoc

All extensions must provide a partial or full implementation of the IBurpExtender interface, and dynamically load this into the Burp process on startup.

Within your IBurpExtender implementation, you can handle key runtime events, such as processing and modifying HTTP requests made by Burp, and receiving notification of new scan issues as these are generated by Burp Scanner. If you implement IBurpExtender.registerExtenderCallbacks(), Burp will pass to your extension an implementation of the IBurpExtenderCallbacks interface, which your extension can use to carry out numerous actions asynchronously. Using the callbacks interface, you can:

Access runtime data including the Proxy history and site map.
Initiate actions like scanning and spidering.
Send requests to Burp tools like Repeater and Intruder.
Read and modify all of Burp's configuration settings.
Query and update the Suite-wide target scope.
Issue arbitrary HTTP requests and retrieve responses.
Create custom menu items to appear on the context menus used within Burp.
Save and restore Burp's state.
Issue alerts via the Burp Suite alerts tab.

The other Burp Extender interfaces are used within the functionality described above, and provide methods to access details of HTTP messages, scan issues and items in the active scan queue.

The functionality exposed by these interfaces enables developers to build powerful extensions to Burp Suite. For example, you can:

Perform customized logging of all requests and responses made via Burp, to a database or file.
Generate customized reports of scan issues, or feed these into other tools in real-time.
Apply application-specific modifications automatically to outgoing requests, for example to recalculate a checksum in requests made by the Scanner or Intruder.
Extract interesting, application-specific data from responses.
Create custom context menu items to perform repetitive, application-specific tasks, such as decoding/encoding data that uses a custom serialization scheme.
Automatically recover your session when this is terminated due to scanning etc., by inspecting each application response to identify a terminated session, re-performing the application login to obtain a fresh session, and inserting the new session token into subsequent requests. This enables you to continue using tools like Scanner and Intruder in the face of aggressive session termination and arbitrarily complex login mechanisms.
Automate regression testing, by restoring a previous state file, and re-performing scanning of the site map or proxy history, to test fixes for previously identified bugs or find any new ones.

Below are some simple examples illustrating how to use some of Burp Extender's features:

To make use of Burp Extender, create a class called BurpExtender, in the package burp, which implements one or more methods of the IBurpExtender interface, and place this into the application's classpath at startup. For example, if Burp Suite is loaded from burp.jar, and BurpProxyExtender.jar contains BurpExtender.class, use the following command to launch Burp Suite and load the extension:

java -classpath burp.jar;BurpProxyExtender.jar burp.StartBurp

(On Linux-based platforms, use a colon character instead of the semi-colon as the classpath separator.)