gooMBA

gooMBA is a Hex-Rays Decompiler plugin that simplifies Mixed Boolean-Arithmetic (MBA) expressions. It achieves this using several heuristics and algorithms to achieve orders-of-magnitude better performance than existing state-of-the-art solutions.

More information on the inner workings of this tool is available in our blog post.

Core Features

Full integration with the Hex-Rays Decompiler
Simplifies linear MBAs, including opaque predicates
Handles sign extension for linear functions
Verifies soundness of simplifications using the z3 SMT solver
Simplifies non-linear MBAs with the use of a function fingerprint oracle

Usage

By default, the plugin does not run automatically. You can invoke the plugin by right clicking in the pseudocode view and selecting "Run gooMBA Optimizer". In addition, you can set up a keyboard shortcut in IDA by opening Options -> Shortcuts... and adding a shortcut for the goomba:run action.

Several options for usage are available within goomba.cfg. You can set up a fingerprint oracle, configure the z3 proof timeout time, choose the desired behavior when timeouts occur, and choose to make the plugin run automatically without needing to be invoked from the right-click menu.

Demo

The sample database tests/idb/mba_challenge.i64 was created from the mba_challenge binary. The functions mba1, mba2, mba3, mba, solve_me contain MBA expressions of varying complexity.

For example, the mba1 function's initial pseudocode:

And after running gooMBA optimization:

Fingerprint oracle

The oracle can be used for simplifying non-linear MBAs. The input for generaring it is a list of candidate expressions in msynth syntax. You can use generate_oracle.sh or generate_oracle.bat to generate a binary oracle file which can then be used by the plugin by specifying the path to it in goomba.cfg (parameter MBA_ORACLE_PATH).

A large pre-computed oracle is available here

NOTE: oracle files generated with IDA 8.2 can only be used with 64-bit binaries, otherwise you may hit internal error 30661.

Obtaining gooMBA

Please see the releases section for goomba builds that will work with IDA Pro & IDA Teams v8.2.