Introduction

This repository provides a collection of ready to use binary analysis tools, as well as a framework and a conventional repository structure for developing new tools. Think of it as BAP on Rails. This repository should be seen as a collaboration platform encouraging everyone to fork it, implement an analysis, and share it back with the community. PRs are very welcomed and accepted with no questions asked.

Table of Contents

• Installation - how to install all or some tools
• Usage - how to run tools and analyze results
• Developing - how to develop a new tool
• Contributing - how to contribute a new tool
• Tools
  • checks from the Joint Strike Fighter coding standards
    • av-rule-3 - all functions have a cyclomatic complexity less than 20
    • av-rule-17 - errno is not used as an error indicator
    • av-rule-19 - setlocale et all functions are not be used
    • av-rule-20 - setjmp/longjmp are not be used
    • av-rule-21 - signal handling facilities of <signal.h> are not be used
    • av-rule-22 - The input/output library <stdio.h> shall not be used
    • av-rule-23 - atof, atoi, and atol are not be used
    • av-rule-24 - abort, exit, getenv and system are not be used
    • av-rule-25 - the <time.h> interface is not used
    • av-rule-174 - potential null pointer dereferencings
    • av-rule-189 - goto statements are not used
  • checks from the JPL Institutional Coding Standard
    • jpl-rule-4 - no recursive functions
    • jpl-rule-11 - goto statements are not used
    • jpl-rule-14 - return values of all non-void functions are used
  • forbidden-symbols - detects all forbidden symbols from the av-rule-{17,19,20,21,22,23,24,25}
  • defective-symbols - detects all defective symbols from the av-rule-{3,189} and jpl-rule-4
  • untrusted-argument - checks that certain functions never use untrusted data
  • must-check-value - detects an unchecked return value of certain functions
  • use-after-free - detects a usage of a pointer that was freed before
  • double-free - detects a pointer that is freed twice
  • restrictness-check - detects an incorrect invocation of a function with strictness requirement
  • warn-unused - detects an unused value returned by a function with warn-unused attribute
  • primus-checks - an all-in-one analysis that uses Primus to identify the following CWE:
    • CWE-122 (Buffer Overwrite)
    • CWE-125 (Buffer Overread)
    • CWE-416 (Use after free)
    • CWE-415 (Double free)
    • CWE-798 (Use of Hard-coded Credentials)
    • CWE-259 (Use of Hard-coded Password)
    • CWE-822 (Untrusted Pointer Dereference)
    • CWE-291 (Relience on IP Address for Authentication)
    • CWE-170 (Improper Null Termination)
    • CWE-138 (Improper Neutralization)
    • CWE-74 (Command Injection)
    • CWE-476 (NULL pointer dereference)
    • CWE-690 (Unchecked Return Value to NULL Pointer Dereference)
    • CWE-252 (Unchecked Return Value)

Usage

You need to install the toolkit before using it. You can either use docker and install it directly on your host machine.

The tools in bap-toolkit are packed as BAP recipes, therefore to run a tool just pass its name to the --recipe option, e.g.,

   bap ./exe --recipe=av-rule-3

To get a detailed description of a recipe, use the --show-recipe option, e.g.,

   bap --show-recipe=av-rule-3

You can also list all available using the --list-recipes option,

   bap --list-recipes

Using bap-toolkit with docker

You don't need to install bap or OCaml to use and develop bap-toolkit if you have deocker installed on your machine.

1. Clone this repository and enter the directory:

git clone https://github.com/BinaryAnalysisPlatform/bap-toolkit.git
cd bap-toolkit

2. Build the image (do not miss the dot at the end of the command)

docker build -t bap-toolkit .

3. Now we have the bap-toolkit container that we can use to run any tool. Let's chekc that it works, the default command is to run the defective-symbol tool on /usr/bin/arch, which should produce one FAIL and two PASSes, e.g.,

$ docker run bap-toolkit
Check                     Status
non structural cfg        FAIL
recursive function        OK
complex function          OK

Running an arbitrary tool on an arbitrary file

If you want to run a tool on your binary, the easiest option is to mount the current working directory (that contains your binary) to the /bap-toolkit folder, which is the working directory of the container. Let's assume that your binary is called tests and that you want to run the spectre tool,

docker run -it --rm -v $(pwd):/bap-toolkit bap-toolkit bap test --recipe=spectre

After analysis finishes, you will then find the incindents file in your host current folder, in which you can find all reported spectre vulnerabilities, e.g.,

$ grep spectre-path incidents
(spectre-path (1:63u#3439 (7 (S3 (cond 4005c8) (load 4005cf) (last 4005de)))))

Developing tools with docker

You can modify any existing file (including *.ml files) in the bap-toolkit folder or develop an new tool and then just rebuild the image with,

docker build -t bap-toolkit .

Rinse and repeat!

Installation

To build the toolkit you need to activate opam,

    eval $(opam env)

Next, to install all tools in the repository to the default share folder just do

    make
    make install

To install a specific tool, run the same commands but pass the tool name to them, e.g.,

    make TARGET=primus-checks
    make install TARGET=primus-checks

Results

The results of the checks from this repository applied to bap-artifacts can be seen here

Developing

Creating a new tool

To create a new tool clone this repository,

  https://github.com/BinaryAnalysisPlatform/bap-toolkit.git

Then create a new folder inside the newly cloned bap-toolkit folder,

  cd bap-toolkit
  mkdir my-first-tool
  cd my-first-tool

All files in this folder will form the body of your tool. They may contain input files, scripts for pre and post processing, BAP plugins and libraries, etc. The only required file is the recipe.scm file which is the entry point of your tool. This file contains a list of options which are passed to bap, for example, to create a tool that just dumps a file in multiple formats, create a recipe.scm file with the following contents

  (option dump asm:out.asm)
  (option dump bir:out.bir)

After the tool is built and installed, you can run it with

  bap ./test-file --recipe=my-first-tool

And this would essentially the same as running bap with the following command line arguments

  bap ./test-file --dump=asm:out.asm --dump=bir:out.bir

Not a big deal so far, but typical bap invocation may contain lots of command line option. You may also need to pass files, header files, BAP Lisp scripts, etc. This is where the recipe system shines. In general, the recipe specification contains a list of recipe items in an arbitrary order. Each item is either a command line option, a parameter, or a reference to another recipe. All items share the same syntax - they are flat s-expressions, i.e., a whitespace separated list of strings enclosed in parentheses. The first string in the list denotes the type of the item, e.g.,

    (option run-entry-points malloc calloc free)

The option command requires one mandatory parameter, the option name, and an arbitrary number of arguments that will be passed to the corresponding command line option. If there are more than one argument then they will be concatenated with the comman symbol, e.g.,

    (option opt a b c d)

will be translated to

    --opt=a,b,c,d

Option arguments may contain substitution symbols. A subsitution symbol starts with the dollar sign, that is followed by a named (optionally delimited with curly braces, to disambiguate it from the rest of the argument). There is one built in parameter prefix, that is substituted with the path to the recipe top folder.

The parameter command introduces a parameter to the recipe, i.e., a variable ingredient that could be changed when the recipe is used. The parameter command has 3 arguments, all required. The first argument is the parameter name, the second is the default value, that is used if the parameter wasn't set, and the last argument is the parameter description. The substitution symbol will be replaced with the default value of a parameter, if a value of the parameter wasn't passed through the command line. Example,

(parameter depth 128 "maximum depth of analysis")
(option analysis-depth $depth)

If the parameter is not set through the command line, then it will be substituted with 128 otherwise it will receive whatever value a user has passed.

Finally, the extend command is like the #include statement in the C preprocessor as it includes all the ingredients from another recipe. (Make sure that you're not introducing loops!). The command has one mandatory argument, the name of the recipe to include.

The recipe file grammar

The grammar is specified below, but for the details and up-to-date information, please refer to bap recipe --help

       recipe ::= {<recipe-item>}
       recipe-item ::= <option> | <parameter> | <extend> | <command>
       option ::= (option <atom> {<atom>})
       parameter ::= (parameter <atom> <atom> <atom>)
       extend ::= (extend <atom>)
       command ::= (command <atom>)