Blackbox Protobuf

Blackbox Protobuf now has an official package on PyPi under the name bbpb. The blackboxprotobuf package is an older fork

Description

Blackbox Protobuf is a set of tools for working with encoded Protocol Buffers (protobuf) without the matching protobuf definition.

Protobuf is a binary serialization format from Google which can be used as a more efficient alternative to formats like JSON or XML. Developers can define the message format in a .proto file and use the protobuf compiler to generate message handlers in their language of choice. The protobuf encoding is binary, and unlike json/xml not human readable or easy to modify by hand. The format also takes advantage of both sides having the message definition and strips out much of the type information. This is good for efficiency, but increases the difficulty analyzing or modifying the network traffic.

Blackbox protobuf is designed to allow working with protocol buffers without the message definition. It was originally implemented as a Burp extension for decoding and modifying messages during mobile pentests, but has also been used for reverse engineering and forensics tooling.

Tools

This repository contains several interfaces for working with protocol buffers:

• A jython burp extension in burp/
• A python library that can be used in other applications in lib/
• A python-based CLI embedded in the library
• A mitmproxy addon in mitmproxy

Documentation

In addition to the README.md for each tool, the following documentation is available:

• Type Definition Guide - guide for editing typedefs to fix types and improve readability

Future Tools

Some tooling that may be built on top of blackboxprotobuf in the future:

• protobuf type discovery tool