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modernize docs and readme for qemu and unicorn
This commit is contained in:
@ -1,109 +0,0 @@
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=========================================================
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Unicorn-based binary-only instrumentation for afl-fuzz
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=========================================================
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1) Introduction
|
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||||||
---------------
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||||||
|
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The code in ./unicorn_mode allows you to build a standalone feature that
|
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||||||
leverages the Unicorn Engine and allows callers to obtain instrumentation
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||||||
output for black-box, closed-source binary code snippets. This mechanism
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can be then used by afl-fuzz to stress-test targets that couldn't be built
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with afl-gcc or used in QEMU mode, or with other extensions such as
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TriforceAFL.
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There is a significant performance penalty compared to native AFL,
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but at least we're able to use AFL on these binaries, right?
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The idea and much of the implementation comes from Nathan Voss <njvoss299@gmail.com>.
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2) How to use
|
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||||||
-------------
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Requirements: you need an installed python2 environment.
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*** Building AFL's Unicorn Mode ***
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First, make afl as usual.
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Once that completes successfully you need to build and add in the Unicorn Mode
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features:
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$ cd unicorn_mode
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$ ./build_unicorn_support.sh
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NOTE: This script downloads a recent Unicorn Engine commit that has been tested
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and is stable-ish from the Unicorn github page. If you are offline, you'll need
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to hack up this script a little bit and supply your own copy of Unicorn's latest
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stable release. It's not very hard, just check out the beginning of the
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build_unicorn_support.sh script and adjust as necessary.
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Building Unicorn will take a little bit (~5-10 minutes). Once it completes
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it automatically compiles a sample application and verify that it works.
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*** Fuzzing with Unicorn Mode ***
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To really use unicorn-mode effectively you need to prepare the following:
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* Relevant binary code to be fuzzed
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* Knowledge of the memory map and good starting state
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* Folder containing sample inputs to start fuzzing with
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- Same ideas as any other AFL inputs
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- Quality/speed of results will depend greatly on quality of starting
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samples
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- See AFL's guidance on how to create a sample corpus
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* Unicorn-based test harness which:
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- Adds memory map regions
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- Loads binary code into memory
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- Emulates at least one instruction*
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- Yeah, this is lame. See 'Gotchas' section below for more info
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- Loads and verifies data to fuzz from a command-line specified file
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- AFL will provide mutated inputs by changing the file passed to
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the test harness
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- Presumably the data to be fuzzed is at a fixed buffer address
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- If input constraints (size, invalid bytes, etc.) are known they
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should be checked after the file is loaded. If a constraint
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fails, just exit the test harness. AFL will treat the input as
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'uninteresting' and move on.
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- Sets up registers and memory state for beginning of test
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- Emulates the interested code from beginning to end
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- If a crash is detected, the test harness must 'crash' by
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throwing a signal (SIGSEGV, SIGKILL, SIGABORT, etc.)
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Once you have all those things ready to go you just need to run afl-fuzz in
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'unicorn-mode' by passing in the '-U' flag:
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$ afl-fuzz -U -m none -i /path/to/inputs -o /path/to/results -- ./test_harness @@
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The normal afl-fuzz command line format applies to everything here. Refer to
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AFL's main documentation for more info about how to use afl-fuzz effectively.
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For a much clearer vision of what all of this looks like, please refer to the
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||||||
sample provided in the 'unicorn_mode/samples' directory. There is also a blog
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||||||
post that goes over the basics at:
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https://medium.com/@njvoss299/afl-unicorn-fuzzing-arbitrary-binary-code-563ca28936bf
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||||||
|
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The 'helper_scripts' directory also contains several helper scripts that allow you
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|
||||||
to dump context from a running process, load it, and hook heap allocations. For details
|
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||||||
on how to use this check out the follow-up blog post to the one linked above.
|
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||||||
|
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||||||
A example use of AFL-Unicorn mode is discussed in the Paper Unicorefuzz:
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||||||
https://www.usenix.org/conference/woot19/presentation/maier
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||||||
|
|
||||||
3) Gotchas, feedback, bugs
|
|
||||||
--------------------------
|
|
||||||
|
|
||||||
To make sure that AFL's fork server starts up correctly the Unicorn test
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|
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harness script must emulate at least one instruction before loading the
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||||||
data that will be fuzzed from the input file. It doesn't matter what the
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instruction is, nor if it is valid. This is an artifact of how the fork-server
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is started and could likely be fixed with some clever re-arranging of the
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||||||
patches applied to Unicorn.
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||||||
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Running the build script builds Unicorn and its python bindings and installs
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|
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them on your system. This installation will supersede any existing Unicorn
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installation with the patched afl-unicorn version.
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||||||
|
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||||||
Refer to the unicorn_mode/samples/arm_example/arm_tester.c for an example
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||||||
of how to do this properly! If you don't get this right, AFL will not
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||||||
load any mutated inputs and your fuzzing will be useless!
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|
@ -1,11 +1,8 @@
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|||||||
=========================================================
|
# High-performance binary-only instrumentation for afl-fuzz
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||||||
High-performance binary-only instrumentation for afl-fuzz
|
|
||||||
=========================================================
|
|
||||||
|
|
||||||
(See ../docs/README for the general instruction manual.)
|
(See ../docs/README for the general instruction manual.)
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||||||
|
|
||||||
1) Introduction
|
## 1) Introduction
|
||||||
---------------
|
|
||||||
|
|
||||||
The code in this directory allows you to build a standalone feature that
|
The code in this directory allows you to build a standalone feature that
|
||||||
leverages the QEMU "user emulation" mode and allows callers to obtain
|
leverages the QEMU "user emulation" mode and allows callers to obtain
|
||||||
@ -20,8 +17,7 @@ The idea and much of the initial implementation comes from Andrew Griffiths.
|
|||||||
The actual implementation on QEMU 3 (shipped with afl++) is from
|
The actual implementation on QEMU 3 (shipped with afl++) is from
|
||||||
Andrea Fioraldi. Special thanks to abiondo that re-enabled TCG chaining.
|
Andrea Fioraldi. Special thanks to abiondo that re-enabled TCG chaining.
|
||||||
|
|
||||||
2) How to use
|
## 2) How to use
|
||||||
-------------
|
|
||||||
|
|
||||||
The feature is implemented with a patch to QEMU 3.1.0. The simplest way
|
The feature is implemented with a patch to QEMU 3.1.0. The simplest way
|
||||||
to build it is to run ./build_qemu_support.sh. The script will download,
|
to build it is to run ./build_qemu_support.sh. The script will download,
|
||||||
@ -48,16 +44,15 @@ Note: if you want the QEMU helper to be installed on your system for all
|
|||||||
users, you need to build it before issuing 'make install' in the parent
|
users, you need to build it before issuing 'make install' in the parent
|
||||||
directory.
|
directory.
|
||||||
|
|
||||||
3) Options
|
## 3) Options
|
||||||
----------
|
|
||||||
|
|
||||||
There is ./libcompcov/ which implements laf-intel (splitting memcmp,
|
There is ./libcompcov/ which implements laf-intel (splitting memcmp,
|
||||||
strncmp, etc. to make these conditions easier solvable by afl-fuzz).
|
strncmp, etc. to make these conditions easier solvable by afl-fuzz).
|
||||||
Highly recommended.
|
Highly recommended.
|
||||||
|
|
||||||
The option that enables QEMU CompareCoverage is QEMU_COMPCOV_LEVEL.
|
The option that enables QEMU CompareCoverage is AFL_COMPCOV_LEVEL.
|
||||||
QEMU_COMPCOV_LEVEL=1 is to instrument comparisons with only immediate
|
AFL_COMPCOV_LEVEL=1 is to instrument comparisons with only immediate
|
||||||
values / read-only memory. QEMU_COMPCOV_LEVEL=2 instruments all
|
values / read-only memory. AFL_COMPCOV_LEVEL=2 instruments all
|
||||||
comparison instructions and memory comparison functions when libcompcov
|
comparison instructions and memory comparison functions when libcompcov
|
||||||
is preloaded. Comparison instructions are currently instrumented only
|
is preloaded. Comparison instructions are currently instrumented only
|
||||||
on the x86 and x86_64 targets.
|
on the x86 and x86_64 targets.
|
||||||
@ -68,8 +63,7 @@ opened (e.g. way after command line parsing and config file loading, etc)
|
|||||||
which can be a huge speed improvement. Note that the specified address
|
which can be a huge speed improvement. Note that the specified address
|
||||||
must be an address of a basic block.
|
must be an address of a basic block.
|
||||||
|
|
||||||
4) Notes on linking
|
## 4) Notes on linking
|
||||||
-------------------
|
|
||||||
|
|
||||||
The feature is supported only on Linux. Supporting BSD may amount to porting
|
The feature is supported only on Linux. Supporting BSD may amount to porting
|
||||||
the changes made to linux-user/elfload.c and applying them to
|
the changes made to linux-user/elfload.c and applying them to
|
||||||
@ -90,8 +84,7 @@ practice, this means two things:
|
|||||||
Setting AFL_INST_LIBS=1 can be used to circumvent the .text detection logic
|
Setting AFL_INST_LIBS=1 can be used to circumvent the .text detection logic
|
||||||
and instrument every basic block encountered.
|
and instrument every basic block encountered.
|
||||||
|
|
||||||
5) Benchmarking
|
## 5) Benchmarking
|
||||||
---------------
|
|
||||||
|
|
||||||
If you want to compare the performance of the QEMU instrumentation with that of
|
If you want to compare the performance of the QEMU instrumentation with that of
|
||||||
afl-gcc compiled code against the same target, you need to build the
|
afl-gcc compiled code against the same target, you need to build the
|
||||||
@ -106,8 +99,7 @@ Comparative measurements of execution speed or instrumentation coverage will be
|
|||||||
fairly meaningless if the optimization levels or instrumentation scopes don't
|
fairly meaningless if the optimization levels or instrumentation scopes don't
|
||||||
match.
|
match.
|
||||||
|
|
||||||
6) Gotchas, feedback, bugs
|
## 6) Gotchas, feedback, bugs
|
||||||
--------------------------
|
|
||||||
|
|
||||||
If you need to fix up checksums or do other cleanup on mutated test cases, see
|
If you need to fix up checksums or do other cleanup on mutated test cases, see
|
||||||
experimental/post_library/ for a viable solution.
|
experimental/post_library/ for a viable solution.
|
||||||
@ -128,8 +120,7 @@ with -march=core2, can help.
|
|||||||
Beyond that, this is an early-stage mechanism, so fields reports are welcome.
|
Beyond that, this is an early-stage mechanism, so fields reports are welcome.
|
||||||
You can send them to <afl-users@googlegroups.com>.
|
You can send them to <afl-users@googlegroups.com>.
|
||||||
|
|
||||||
7) Alternatives: static rewriting
|
## 7) Alternatives: static rewriting
|
||||||
---------------------------------
|
|
||||||
|
|
||||||
Statically rewriting binaries just once, instead of attempting to translate
|
Statically rewriting binaries just once, instead of attempting to translate
|
||||||
them at run time, can be a faster alternative. That said, static rewriting is
|
them at run time, can be a faster alternative. That said, static rewriting is
|
@ -3,10 +3,17 @@
|
|||||||
# american fuzzy lop - QEMU build script
|
# american fuzzy lop - QEMU build script
|
||||||
# --------------------------------------
|
# --------------------------------------
|
||||||
#
|
#
|
||||||
# Written by Andrew Griffiths <agriffiths@google.com> and
|
# Originally written by Andrew Griffiths <agriffiths@google.com> and
|
||||||
# Michal Zalewski <lcamtuf@google.com>
|
# Michal Zalewski <lcamtuf@google.com>
|
||||||
|
#
|
||||||
|
# TCG instrumentation and block chaining support by Andrea Biondo
|
||||||
|
# <andrea.biondo965@gmail.com>
|
||||||
|
#
|
||||||
|
# QEMU 3.1.0 port, TCG thread-safety, CompareCoverage and NeverZero
|
||||||
|
# counters by Andrea Fioraldi <andreafioraldi@gmail.com>
|
||||||
#
|
#
|
||||||
# Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
|
# Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
|
||||||
|
# Copyright 2019 AFLplusplus Project. All rights reserved.
|
||||||
#
|
#
|
||||||
# Licensed under the Apache License, Version 2.0 (the "License");
|
# Licensed under the Apache License, Version 2.0 (the "License");
|
||||||
# you may not use this file except in compliance with the License.
|
# you may not use this file except in compliance with the License.
|
||||||
|
@ -5,7 +5,7 @@
|
|||||||
|
|
||||||
Written and maintained by Andrea Fioraldi <andreafioraldi@gmail.com>
|
Written and maintained by Andrea Fioraldi <andreafioraldi@gmail.com>
|
||||||
|
|
||||||
Copyright 2019 Andrea Fioraldi. All rights reserved.
|
Copyright 2019 AFLplusplus Project. All rights reserved.
|
||||||
|
|
||||||
Licensed under the Apache License, Version 2.0 (the "License");
|
Licensed under the Apache License, Version 2.0 (the "License");
|
||||||
you may not use this file except in compliance with the License.
|
you may not use this file except in compliance with the License.
|
||||||
|
@ -1,19 +1,18 @@
|
|||||||
/*
|
/*
|
||||||
american fuzzy lop - high-performance binary-only instrumentation
|
american fuzzy lop++ - high-performance binary-only instrumentation
|
||||||
-----------------------------------------------------------------
|
-------------------------------------------------------------------
|
||||||
|
|
||||||
Written by Andrew Griffiths <agriffiths@google.com> and
|
Originally written by Andrew Griffiths <agriffiths@google.com> and
|
||||||
Michal Zalewski <lcamtuf@google.com>
|
Michal Zalewski <lcamtuf@google.com>
|
||||||
|
|
||||||
Idea & design very much by Andrew Griffiths.
|
|
||||||
|
|
||||||
TCG instrumentation and block chaining support by Andrea Biondo
|
TCG instrumentation and block chaining support by Andrea Biondo
|
||||||
<andrea.biondo965@gmail.com>
|
<andrea.biondo965@gmail.com>
|
||||||
|
|
||||||
QEMU 3.1.0 port, TCG thread-safety and CompareCoverage by Andrea Fioraldi
|
QEMU 3.1.0 port, TCG thread-safety, CompareCoverage and NeverZero
|
||||||
<andreafioraldi@gmail.com>
|
counters by Andrea Fioraldi <andreafioraldi@gmail.com>
|
||||||
|
|
||||||
Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
|
Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
|
||||||
|
Copyright 2019 AFLplusplus Project. All rights reserved.
|
||||||
|
|
||||||
Licensed under the Apache License, Version 2.0 (the "License");
|
Licensed under the Apache License, Version 2.0 (the "License");
|
||||||
you may not use this file except in compliance with the License.
|
you may not use this file except in compliance with the License.
|
||||||
|
@ -1,19 +1,18 @@
|
|||||||
/*
|
/*
|
||||||
american fuzzy lop - high-performance binary-only instrumentation
|
american fuzzy lop++ - high-performance binary-only instrumentation
|
||||||
-----------------------------------------------------------------
|
-------------------------------------------------------------------
|
||||||
|
|
||||||
Written by Andrew Griffiths <agriffiths@google.com> and
|
Originally written by Andrew Griffiths <agriffiths@google.com> and
|
||||||
Michal Zalewski <lcamtuf@google.com>
|
Michal Zalewski <lcamtuf@google.com>
|
||||||
|
|
||||||
Idea & design very much by Andrew Griffiths.
|
|
||||||
|
|
||||||
TCG instrumentation and block chaining support by Andrea Biondo
|
TCG instrumentation and block chaining support by Andrea Biondo
|
||||||
<andrea.biondo965@gmail.com>
|
<andrea.biondo965@gmail.com>
|
||||||
|
|
||||||
QEMU 3.1.0 port, TCG thread-safety and CompareCoverage by Andrea Fioraldi
|
QEMU 3.1.0 port, TCG thread-safety, CompareCoverage and NeverZero
|
||||||
<andreafioraldi@gmail.com>
|
counters by Andrea Fioraldi <andreafioraldi@gmail.com>
|
||||||
|
|
||||||
Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
|
Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
|
||||||
|
Copyright 2019 AFLplusplus Project. All rights reserved.
|
||||||
|
|
||||||
Licensed under the Apache License, Version 2.0 (the "License");
|
Licensed under the Apache License, Version 2.0 (the "License");
|
||||||
you may not use this file except in compliance with the License.
|
you may not use this file except in compliance with the License.
|
||||||
|
@ -1,19 +1,18 @@
|
|||||||
/*
|
/*
|
||||||
american fuzzy lop - high-performance binary-only instrumentation
|
american fuzzy lop++ - high-performance binary-only instrumentation
|
||||||
-----------------------------------------------------------------
|
-------------------------------------------------------------------
|
||||||
|
|
||||||
Written by Andrew Griffiths <agriffiths@google.com> and
|
Originally written by Andrew Griffiths <agriffiths@google.com> and
|
||||||
Michal Zalewski <lcamtuf@google.com>
|
Michal Zalewski <lcamtuf@google.com>
|
||||||
|
|
||||||
Idea & design very much by Andrew Griffiths.
|
|
||||||
|
|
||||||
TCG instrumentation and block chaining support by Andrea Biondo
|
TCG instrumentation and block chaining support by Andrea Biondo
|
||||||
<andrea.biondo965@gmail.com>
|
<andrea.biondo965@gmail.com>
|
||||||
|
|
||||||
QEMU 3.1.0 port, TCG thread-safety and CompareCoverage by Andrea Fioraldi
|
QEMU 3.1.0 port, TCG thread-safety, CompareCoverage and NeverZero
|
||||||
<andreafioraldi@gmail.com>
|
counters by Andrea Fioraldi <andreafioraldi@gmail.com>
|
||||||
|
|
||||||
Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
|
Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
|
||||||
|
Copyright 2019 AFLplusplus Project. All rights reserved.
|
||||||
|
|
||||||
Licensed under the Apache License, Version 2.0 (the "License");
|
Licensed under the Apache License, Version 2.0 (the "License");
|
||||||
you may not use this file except in compliance with the License.
|
you may not use this file except in compliance with the License.
|
||||||
|
@ -1,19 +1,18 @@
|
|||||||
/*
|
/*
|
||||||
american fuzzy lop - high-performance binary-only instrumentation
|
american fuzzy lop++ - high-performance binary-only instrumentation
|
||||||
-----------------------------------------------------------------
|
-------------------------------------------------------------------
|
||||||
|
|
||||||
Written by Andrew Griffiths <agriffiths@google.com> and
|
Originally written by Andrew Griffiths <agriffiths@google.com> and
|
||||||
Michal Zalewski <lcamtuf@google.com>
|
Michal Zalewski <lcamtuf@google.com>
|
||||||
|
|
||||||
Idea & design very much by Andrew Griffiths.
|
|
||||||
|
|
||||||
TCG instrumentation and block chaining support by Andrea Biondo
|
TCG instrumentation and block chaining support by Andrea Biondo
|
||||||
<andrea.biondo965@gmail.com>
|
<andrea.biondo965@gmail.com>
|
||||||
|
|
||||||
QEMU 3.1.0 port, TCG thread-safety and CompareCoverage by Andrea Fioraldi
|
QEMU 3.1.0 port, TCG thread-safety, CompareCoverage and NeverZero
|
||||||
<andreafioraldi@gmail.com>
|
counters by Andrea Fioraldi <andreafioraldi@gmail.com>
|
||||||
|
|
||||||
Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
|
Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
|
||||||
|
Copyright 2019 AFLplusplus Project. All rights reserved.
|
||||||
|
|
||||||
Licensed under the Apache License, Version 2.0 (the "License");
|
Licensed under the Apache License, Version 2.0 (the "License");
|
||||||
you may not use this file except in compliance with the License.
|
you may not use this file except in compliance with the License.
|
||||||
|
@ -1,19 +1,18 @@
|
|||||||
/*
|
/*
|
||||||
american fuzzy lop - high-performance binary-only instrumentation
|
american fuzzy lop++ - high-performance binary-only instrumentation
|
||||||
-----------------------------------------------------------------
|
-------------------------------------------------------------------
|
||||||
|
|
||||||
Written by Andrew Griffiths <agriffiths@google.com> and
|
Originally written by Andrew Griffiths <agriffiths@google.com> and
|
||||||
Michal Zalewski <lcamtuf@google.com>
|
Michal Zalewski <lcamtuf@google.com>
|
||||||
|
|
||||||
Idea & design very much by Andrew Griffiths.
|
|
||||||
|
|
||||||
TCG instrumentation and block chaining support by Andrea Biondo
|
TCG instrumentation and block chaining support by Andrea Biondo
|
||||||
<andrea.biondo965@gmail.com>
|
<andrea.biondo965@gmail.com>
|
||||||
|
|
||||||
QEMU 3.1.0 port, TCG thread-safety and CompareCoverage by Andrea Fioraldi
|
QEMU 3.1.0 port, TCG thread-safety, CompareCoverage and NeverZero
|
||||||
<andreafioraldi@gmail.com>
|
counters by Andrea Fioraldi <andreafioraldi@gmail.com>
|
||||||
|
|
||||||
Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
|
Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
|
||||||
|
Copyright 2019 AFLplusplus Project. All rights reserved.
|
||||||
|
|
||||||
Licensed under the Apache License, Version 2.0 (the "License");
|
Licensed under the Apache License, Version 2.0 (the "License");
|
||||||
you may not use this file except in compliance with the License.
|
you may not use this file except in compliance with the License.
|
||||||
|
@ -1,23 +1,119 @@
|
|||||||
```
|
# Unicorn-based binary-only instrumentation for afl-fuzz
|
||||||
__ _ _
|
|
||||||
__ _ / _| | _ _ _ __ (_) ___ ___ _ __ _ __
|
|
||||||
/ _` | |_| |___| | | | '_ \| |/ __/ _ \| '__| '_ \
|
|
||||||
| (_| | _| |___| |_| | | | | | (_| (_) | | | | | |
|
|
||||||
\__,_|_| |_| \__,_|_| |_|_|\___\___/|_| |_| |_|
|
|
||||||
|
|
||||||
```
|
The idea and much of the original implementation comes from Nathan Voss <njvoss299@gmail.com>.
|
||||||
|
|
||||||
afl-unicorn lets you fuzz any piece of binary that can be emulated by
|
The port to afl++ if by Dominik Maier <mail@dmnk.co>.
|
||||||
[Unicorn Engine](http://www.unicorn-engine.org/).
|
|
||||||
|
|
||||||
Requirements: Python2
|
The CompareCoverage and NeverZero counters features by Andrea Fioraldi <andreafioraldi@gmail.com>.
|
||||||
|
|
||||||
For the full readme please see docs/unicorn_mode.txt
|
## 1) Introduction
|
||||||
|
|
||||||
For an in-depth description of what this is, how to install it, and how to use
|
The code in ./unicorn_mode allows you to build a standalone feature that
|
||||||
it check out this [blog post](https://medium.com/@njvoss299/afl-unicorn-fuzzing-arbitrary-binary-code-563ca28936bf).
|
leverages the Unicorn Engine and allows callers to obtain instrumentation
|
||||||
|
output for black-box, closed-source binary code snippets. This mechanism
|
||||||
|
can be then used by afl-fuzz to stress-test targets that couldn't be built
|
||||||
|
with afl-gcc or used in QEMU mode, or with other extensions such as
|
||||||
|
TriforceAFL.
|
||||||
|
|
||||||
For general help with AFL, please refer to the documents in the ./docs/ directory.
|
There is a significant performance penalty compared to native AFL,
|
||||||
|
but at least we're able to use AFL on these binaries, right?
|
||||||
|
|
||||||
Created by Nathan Voss, originally funded by
|
## 2) How to use
|
||||||
[Battelle](https://www.battelle.org/cyber).
|
|
||||||
|
Requirements: you need an installed python2 environment.
|
||||||
|
|
||||||
|
### Building AFL's Unicorn Mode
|
||||||
|
|
||||||
|
First, make afl++ as usual.
|
||||||
|
Once that completes successfully you need to build and add in the Unicorn Mode
|
||||||
|
features:
|
||||||
|
|
||||||
|
$ cd unicorn_mode
|
||||||
|
$ ./build_unicorn_support.sh
|
||||||
|
|
||||||
|
NOTE: This script downloads a Unicorn Engine commit that has been tested
|
||||||
|
and is stable-ish from the Unicorn github page. If you are offline, you'll need
|
||||||
|
to hack up this script a little bit and supply your own copy of Unicorn's latest
|
||||||
|
stable release. It's not very hard, just check out the beginning of the
|
||||||
|
build_unicorn_support.sh script and adjust as necessary.
|
||||||
|
|
||||||
|
Building Unicorn will take a little bit (~5-10 minutes). Once it completes
|
||||||
|
it automatically compiles a sample application and verify that it works.
|
||||||
|
|
||||||
|
### Fuzzing with Unicorn Mode
|
||||||
|
|
||||||
|
To really use unicorn-mode effectively you need to prepare the following:
|
||||||
|
|
||||||
|
* Relevant binary code to be fuzzed
|
||||||
|
* Knowledge of the memory map and good starting state
|
||||||
|
* Folder containing sample inputs to start fuzzing with
|
||||||
|
+ Same ideas as any other AFL inputs
|
||||||
|
+ Quality/speed of results will depend greatly on quality of starting
|
||||||
|
samples
|
||||||
|
+ See AFL's guidance on how to create a sample corpus
|
||||||
|
* Unicorn-based test harness which:
|
||||||
|
+ Adds memory map regions
|
||||||
|
+ Loads binary code into memory
|
||||||
|
+ Emulates at least one instruction*
|
||||||
|
+ Yeah, this is lame. See 'Gotchas' section below for more info
|
||||||
|
+ Loads and verifies data to fuzz from a command-line specified file
|
||||||
|
+ AFL will provide mutated inputs by changing the file passed to
|
||||||
|
the test harness
|
||||||
|
+ Presumably the data to be fuzzed is at a fixed buffer address
|
||||||
|
+ If input constraints (size, invalid bytes, etc.) are known they
|
||||||
|
should be checked after the file is loaded. If a constraint
|
||||||
|
fails, just exit the test harness. AFL will treat the input as
|
||||||
|
'uninteresting' and move on.
|
||||||
|
+ Sets up registers and memory state for beginning of test
|
||||||
|
+ Emulates the interested code from beginning to end
|
||||||
|
+ If a crash is detected, the test harness must 'crash' by
|
||||||
|
throwing a signal (SIGSEGV, SIGKILL, SIGABORT, etc.)
|
||||||
|
|
||||||
|
Once you have all those things ready to go you just need to run afl-fuzz in
|
||||||
|
'unicorn-mode' by passing in the '-U' flag:
|
||||||
|
|
||||||
|
$ afl-fuzz -U -m none -i /path/to/inputs -o /path/to/results -- ./test_harness @@
|
||||||
|
|
||||||
|
The normal afl-fuzz command line format applies to everything here. Refer to
|
||||||
|
AFL's main documentation for more info about how to use afl-fuzz effectively.
|
||||||
|
|
||||||
|
For a much clearer vision of what all of this looks like, please refer to the
|
||||||
|
sample provided in the 'unicorn_mode/samples' directory. There is also a blog
|
||||||
|
post that goes over the basics at:
|
||||||
|
|
||||||
|
https://medium.com/@njvoss299/afl-unicorn-fuzzing-arbitrary-binary-code-563ca28936bf
|
||||||
|
|
||||||
|
The 'helper_scripts' directory also contains several helper scripts that allow you
|
||||||
|
to dump context from a running process, load it, and hook heap allocations. For details
|
||||||
|
on how to use this check out the follow-up blog post to the one linked above.
|
||||||
|
|
||||||
|
A example use of AFL-Unicorn mode is discussed in the Paper Unicorefuzz:
|
||||||
|
https://www.usenix.org/conference/woot19/presentation/maier
|
||||||
|
|
||||||
|
## 3) Options
|
||||||
|
|
||||||
|
As for the QEMU-based instrumentation, the afl-unicorn twist of afl++
|
||||||
|
comes with a sub-instruction based instrumentation similar in purpose to laf-intel.
|
||||||
|
|
||||||
|
The options that enables Unicorn CompareCoverage are the same used for QEMU.
|
||||||
|
AFL_COMPCOV_LEVEL=1 is to instrument comparisons with only immediate
|
||||||
|
values. QEMU_COMPCOV_LEVEL=2 instruments all
|
||||||
|
comparison instructions. Comparison instructions are currently instrumented only
|
||||||
|
on the x86 and x86_64 targets.
|
||||||
|
|
||||||
|
## 4) Gotchas, feedback, bugs
|
||||||
|
|
||||||
|
To make sure that AFL's fork server starts up correctly the Unicorn test
|
||||||
|
harness script must emulate at least one instruction before loading the
|
||||||
|
data that will be fuzzed from the input file. It doesn't matter what the
|
||||||
|
instruction is, nor if it is valid. This is an artifact of how the fork-server
|
||||||
|
is started and could likely be fixed with some clever re-arranging of the
|
||||||
|
patches applied to Unicorn.
|
||||||
|
|
||||||
|
Running the build script builds Unicorn and its python bindings and installs
|
||||||
|
them on your system. This installation will supersede any existing Unicorn
|
||||||
|
installation with the patched afl-unicorn version.
|
||||||
|
|
||||||
|
Refer to the unicorn_mode/samples/arm_example/arm_tester.c for an example
|
||||||
|
of how to do this properly! If you don't get this right, AFL will not
|
||||||
|
load any mutated inputs and your fuzzing will be useless!
|
||||||
|
@ -1,16 +1,20 @@
|
|||||||
#!/bin/sh
|
#!/bin/sh
|
||||||
#
|
#
|
||||||
# american fuzzy lop - Unicorn-Mode build script
|
# american fuzzy lop++ - unicorn mode build script
|
||||||
# --------------------------------------
|
# ------------------------------------------------
|
||||||
#
|
#
|
||||||
# Written by Nathan Voss <njvoss99@gmail.com>
|
# Originally written by Nathan Voss <njvoss99@gmail.com>
|
||||||
#
|
#
|
||||||
# Adapted from code by Andrew Griffiths <agriffiths@google.com> and
|
# Adapted from code by Andrew Griffiths <agriffiths@google.com> and
|
||||||
# Michal Zalewski <lcamtuf@google.com>
|
# Michal Zalewski <lcamtuf@google.com>
|
||||||
#
|
#
|
||||||
# Adapted for Afl++ by Dominik Maier <mail@dmnk.co>
|
# Adapted for AFLplusplus by Dominik Maier <mail@dmnk.co>
|
||||||
|
#
|
||||||
|
# CompareCoverage and NeverZero counters by Andrea Fioraldi
|
||||||
|
# <andreafioraldi@gmail.com>
|
||||||
#
|
#
|
||||||
# Copyright 2017 Battelle Memorial Institute. All rights reserved.
|
# Copyright 2017 Battelle Memorial Institute. All rights reserved.
|
||||||
|
# Copyright 2019 AFLplusplus Project. All rights reserved.
|
||||||
#
|
#
|
||||||
# Licensed under the Apache License, Version 2.0 (the "License");
|
# Licensed under the Apache License, Version 2.0 (the "License");
|
||||||
# you may not use this file except in compliance with the License.
|
# you may not use this file except in compliance with the License.
|
||||||
|
@ -1,17 +1,17 @@
|
|||||||
/*
|
/*
|
||||||
american fuzzy lop - high-performance binary-only instrumentation
|
american fuzzy lop++ - unicorn instrumentation
|
||||||
-----------------------------------------------------------------
|
----------------------------------------------
|
||||||
|
|
||||||
Written by Andrew Griffiths <agriffiths@google.com> and
|
Originally written by Andrew Griffiths <agriffiths@google.com> and
|
||||||
Michal Zalewski <lcamtuf@google.com>
|
Michal Zalewski <lcamtuf@google.com>
|
||||||
|
|
||||||
TCG instrumentation and block chaining support by Andrea Biondo
|
|
||||||
<andrea.biondo965@gmail.com>
|
|
||||||
Adapted for afl-unicorn by Dominik Maier <mail@dmnk.co>
|
Adapted for afl-unicorn by Dominik Maier <mail@dmnk.co>
|
||||||
|
|
||||||
Idea & design very much by Andrew Griffiths.
|
CompareCoverage and NeverZero counters by Andrea Fioraldi
|
||||||
|
<andreafioraldi@gmail.com>
|
||||||
|
|
||||||
Copyright 2015, 2016 Google Inc. All rights reserved.
|
Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
|
||||||
|
Copyright 2019 AFLplusplus Project. All rights reserved.
|
||||||
|
|
||||||
Licensed under the Apache License, Version 2.0 (the "License");
|
Licensed under the Apache License, Version 2.0 (the "License");
|
||||||
you may not use this file except in compliance with the License.
|
you may not use this file except in compliance with the License.
|
||||||
@ -24,7 +24,7 @@
|
|||||||
to implement AFL-style instrumentation and to take care of the remaining
|
to implement AFL-style instrumentation and to take care of the remaining
|
||||||
parts of the AFL fork server logic.
|
parts of the AFL fork server logic.
|
||||||
|
|
||||||
The resulting QEMU binary is essentially a standalone instrumentation
|
The resulting libunicorn binary is essentially a standalone instrumentation
|
||||||
tool; for an example of how to leverage it for other purposes, you can
|
tool; for an example of how to leverage it for other purposes, you can
|
||||||
have a look at afl-showmap.c.
|
have a look at afl-showmap.c.
|
||||||
|
|
||||||
|
@ -1,17 +1,17 @@
|
|||||||
/*
|
/*
|
||||||
american fuzzy lop - high-performance binary-only instrumentation
|
american fuzzy lop++ - unicorn instrumentation
|
||||||
-----------------------------------------------------------------
|
----------------------------------------------
|
||||||
|
|
||||||
Written by Andrew Griffiths <agriffiths@google.com> and
|
Originally written by Andrew Griffiths <agriffiths@google.com> and
|
||||||
Michal Zalewski <lcamtuf@google.com>
|
Michal Zalewski <lcamtuf@google.com>
|
||||||
|
|
||||||
TCG instrumentation and block chaining support by Andrea Biondo
|
|
||||||
<andrea.biondo965@gmail.com>
|
|
||||||
Adapted for afl-unicorn by Dominik Maier <mail@dmnk.co>
|
Adapted for afl-unicorn by Dominik Maier <mail@dmnk.co>
|
||||||
|
|
||||||
Idea & design very much by Andrew Griffiths.
|
CompareCoverage and NeverZero counters by Andrea Fioraldi
|
||||||
|
<andreafioraldi@gmail.com>
|
||||||
|
|
||||||
Copyright 2015, 2016 Google Inc. All rights reserved.
|
Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
|
||||||
|
Copyright 2019 AFLplusplus Project. All rights reserved.
|
||||||
|
|
||||||
Licensed under the Apache License, Version 2.0 (the "License");
|
Licensed under the Apache License, Version 2.0 (the "License");
|
||||||
you may not use this file except in compliance with the License.
|
you may not use this file except in compliance with the License.
|
||||||
@ -24,7 +24,7 @@
|
|||||||
to implement AFL-style instrumentation and to take care of the remaining
|
to implement AFL-style instrumentation and to take care of the remaining
|
||||||
parts of the AFL fork server logic.
|
parts of the AFL fork server logic.
|
||||||
|
|
||||||
The resulting QEMU binary is essentially a standalone instrumentation
|
The resulting libunicorn binary is essentially a standalone instrumentation
|
||||||
tool; for an example of how to leverage it for other purposes, you can
|
tool; for an example of how to leverage it for other purposes, you can
|
||||||
have a look at afl-showmap.c.
|
have a look at afl-showmap.c.
|
||||||
|
|
||||||
|
@ -1,17 +1,17 @@
|
|||||||
/*
|
/*
|
||||||
american fuzzy lop - high-performance binary-only instrumentation
|
american fuzzy lop++ - unicorn instrumentation
|
||||||
-----------------------------------------------------------------
|
----------------------------------------------
|
||||||
|
|
||||||
Written by Andrew Griffiths <agriffiths@google.com> and
|
Originally written by Andrew Griffiths <agriffiths@google.com> and
|
||||||
Michal Zalewski <lcamtuf@google.com>
|
Michal Zalewski <lcamtuf@google.com>
|
||||||
|
|
||||||
TCG instrumentation and block chaining support by Andrea Biondo
|
|
||||||
<andrea.biondo965@gmail.com>
|
|
||||||
Adapted for afl-unicorn by Dominik Maier <mail@dmnk.co>
|
Adapted for afl-unicorn by Dominik Maier <mail@dmnk.co>
|
||||||
|
|
||||||
Idea & design very much by Andrew Griffiths.
|
CompareCoverage and NeverZero counters by Andrea Fioraldi
|
||||||
|
<andreafioraldi@gmail.com>
|
||||||
|
|
||||||
Copyright 2015, 2016 Google Inc. All rights reserved.
|
Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
|
||||||
|
Copyright 2019 AFLplusplus Project. All rights reserved.
|
||||||
|
|
||||||
Licensed under the Apache License, Version 2.0 (the "License");
|
Licensed under the Apache License, Version 2.0 (the "License");
|
||||||
you may not use this file except in compliance with the License.
|
you may not use this file except in compliance with the License.
|
||||||
@ -24,7 +24,7 @@
|
|||||||
to implement AFL-style instrumentation and to take care of the remaining
|
to implement AFL-style instrumentation and to take care of the remaining
|
||||||
parts of the AFL fork server logic.
|
parts of the AFL fork server logic.
|
||||||
|
|
||||||
The resulting QEMU binary is essentially a standalone instrumentation
|
The resulting libunicorn binary is essentially a standalone instrumentation
|
||||||
tool; for an example of how to leverage it for other purposes, you can
|
tool; for an example of how to leverage it for other purposes, you can
|
||||||
have a look at afl-showmap.c.
|
have a look at afl-showmap.c.
|
||||||
|
|
||||||
|
@ -1,17 +1,17 @@
|
|||||||
/*
|
/*
|
||||||
american fuzzy lop - high-performance binary-only instrumentation
|
american fuzzy lop++ - unicorn instrumentation
|
||||||
-----------------------------------------------------------------
|
----------------------------------------------
|
||||||
|
|
||||||
Written by Andrew Griffiths <agriffiths@google.com> and
|
Originally written by Andrew Griffiths <agriffiths@google.com> and
|
||||||
Michal Zalewski <lcamtuf@google.com>
|
Michal Zalewski <lcamtuf@google.com>
|
||||||
|
|
||||||
TCG instrumentation and block chaining support by Andrea Biondo
|
|
||||||
<andrea.biondo965@gmail.com>
|
|
||||||
Adapted for afl-unicorn by Dominik Maier <mail@dmnk.co>
|
Adapted for afl-unicorn by Dominik Maier <mail@dmnk.co>
|
||||||
|
|
||||||
Idea & design very much by Andrew Griffiths.
|
CompareCoverage and NeverZero counters by Andrea Fioraldi
|
||||||
|
<andreafioraldi@gmail.com>
|
||||||
|
|
||||||
Copyright 2015, 2016 Google Inc. All rights reserved.
|
Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
|
||||||
|
Copyright 2019 AFLplusplus Project. All rights reserved.
|
||||||
|
|
||||||
Licensed under the Apache License, Version 2.0 (the "License");
|
Licensed under the Apache License, Version 2.0 (the "License");
|
||||||
you may not use this file except in compliance with the License.
|
you may not use this file except in compliance with the License.
|
||||||
@ -24,7 +24,7 @@
|
|||||||
to implement AFL-style instrumentation and to take care of the remaining
|
to implement AFL-style instrumentation and to take care of the remaining
|
||||||
parts of the AFL fork server logic.
|
parts of the AFL fork server logic.
|
||||||
|
|
||||||
The resulting QEMU binary is essentially a standalone instrumentation
|
The resulting libunicorn binary is essentially a standalone instrumentation
|
||||||
tool; for an example of how to leverage it for other purposes, you can
|
tool; for an example of how to leverage it for other purposes, you can
|
||||||
have a look at afl-showmap.c.
|
have a look at afl-showmap.c.
|
||||||
|
|
||||||
|
@ -1,17 +1,17 @@
|
|||||||
/*
|
/*
|
||||||
american fuzzy lop - high-performance binary-only instrumentation
|
american fuzzy lop++ - unicorn instrumentation
|
||||||
-----------------------------------------------------------------
|
----------------------------------------------
|
||||||
|
|
||||||
Written by Andrew Griffiths <agriffiths@google.com> and
|
Originally written by Andrew Griffiths <agriffiths@google.com> and
|
||||||
Michal Zalewski <lcamtuf@google.com>
|
Michal Zalewski <lcamtuf@google.com>
|
||||||
|
|
||||||
TCG instrumentation and block chaining support by Andrea Biondo
|
|
||||||
<andrea.biondo965@gmail.com>
|
|
||||||
Adapted for afl-unicorn by Dominik Maier <mail@dmnk.co>
|
Adapted for afl-unicorn by Dominik Maier <mail@dmnk.co>
|
||||||
|
|
||||||
Idea & design very much by Andrew Griffiths.
|
CompareCoverage and NeverZero counters by Andrea Fioraldi
|
||||||
|
<andreafioraldi@gmail.com>
|
||||||
|
|
||||||
Copyright 2015, 2016 Google Inc. All rights reserved.
|
Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
|
||||||
|
Copyright 2019 AFLplusplus Project. All rights reserved.
|
||||||
|
|
||||||
Licensed under the Apache License, Version 2.0 (the "License");
|
Licensed under the Apache License, Version 2.0 (the "License");
|
||||||
you may not use this file except in compliance with the License.
|
you may not use this file except in compliance with the License.
|
||||||
@ -24,7 +24,7 @@
|
|||||||
to implement AFL-style instrumentation and to take care of the remaining
|
to implement AFL-style instrumentation and to take care of the remaining
|
||||||
parts of the AFL fork server logic.
|
parts of the AFL fork server logic.
|
||||||
|
|
||||||
The resulting QEMU binary is essentially a standalone instrumentation
|
The resulting libunicorn binary is essentially a standalone instrumentation
|
||||||
tool; for an example of how to leverage it for other purposes, you can
|
tool; for an example of how to leverage it for other purposes, you can
|
||||||
have a look at afl-showmap.c.
|
have a look at afl-showmap.c.
|
||||||
|
|
||||||
|
@ -1,5 +1,4 @@
|
|||||||
Compiling compcov_target.c
|
# Compiling compcov_target.c
|
||||||
==========================
|
|
||||||
|
|
||||||
compcov_target.c was compiled without optimization, position-independent,
|
compcov_target.c was compiled without optimization, position-independent,
|
||||||
and without standard libraries using the following command line:
|
and without standard libraries using the following command line:
|
||||||
|
@ -7,7 +7,7 @@
|
|||||||
* (0x00300000), so make sure that your Unicorn emulation of this
|
* (0x00300000), so make sure that your Unicorn emulation of this
|
||||||
* puts user data there.
|
* puts user data there.
|
||||||
*
|
*
|
||||||
* Written by Nathan Voss <njvoss99@gmail.com>
|
* Written by Andrea Fioraldi
|
||||||
*/
|
*/
|
||||||
|
|
||||||
// Magic address where mutated data will be placed
|
// Magic address where mutated data will be placed
|
||||||
|
@ -1,5 +1,4 @@
|
|||||||
Compiling simple_target.c
|
# Compiling simple_target.c
|
||||||
==========================
|
|
||||||
|
|
||||||
You shouldn't need to compile simple_target.c since a MIPS binary version is
|
You shouldn't need to compile simple_target.c since a MIPS binary version is
|
||||||
pre-built and shipped with afl-unicorn. This file documents how the binary
|
pre-built and shipped with afl-unicorn. This file documents how the binary
|
||||||
|
Reference in New Issue
Block a user