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Android Platform

Honggfuzz (as of version 0.6) supports Android OS (NDK cross-compilation) using both ptrace() API and POSIX signals interface. When ptrace() API is enabled, honggfuzz's engine prevents monitored signals from reaching the debugger (no logcat backtraces & tombstones), since the fuzzer's runtime analysis is affected.

Requirements

  • Android NDK: User has to manually install NDK and set environment PATH
  • libunwind: In case of first build an upstream git fork is executed followed by required patches
  • capstone: In case of first build an upstream git fork is executed
Dependency Last Tested Version
Android NDK r16 with Android API 24 (Nougat 7.0)
libunwind upstream master commit [bc8698f]
capstone 3.0.4 stable version

Compatibility list

It has been tested under the following CPU architectures:

ABI Status
armeabi ptrace() API & POSIX signal interface
armeabi-v7a ptrace() API & POSIX signal interface
arm64-v8a ptrace() API & POSIX signal interface *
x86 ptrace() API & POSIX signal interface
x86_64 ptrace() API & POSIX signal interface

*) libunwind fails to extract frames if fuzzing target is 32bit. Prefer a32bit build for such targets.

Cross-Compiling

Dependencies

A series of helper bash scripts have been created under the third_party/android/scripts directory to automate the dependencies configuration & build process. The scripts are automatically invoked from the makefile, based on the selected target CPU. Normally you'll not need to manually execute or modify them.

Building

All CPUs

For convenience the master makefile defines an android-all target that automatically builds honggfuzz (and its dependencies) for all the supported Android CPUs.

From the root directory execute the following. Build output is available under the libs directory.

$ make android-all
...
$ tree libs/
libs/
├── arm64-v8a
│   ├── android_api.txt
│   ├── honggfuzz
│   ├── libhfuzz.a
│   └── ndk_toolchain.txt
├── armeabi
│   ├── android_api.txt
│   ├── honggfuzz
│   ├── libhfuzz.a
│   └── ndk_toolchain.txt
├── armeabi-v7a
│   ├── android_api.txt
│   ├── honggfuzz
│   ├── libhfuzz.a
│   └── ndk_toolchain.txt
├── x86
│   ├── android_api.txt
│   ├── honggfuzz
│   ├── libhfuzz.a
│   └── ndk_toolchain.txt
└── x86_64
    ├── android_api.txt
    ├── honggfuzz
    ├── libhfuzz.a
    └── ndk_toolchain.txt

5 directories, 20 files

Specific CPU

To build for a specific CPU use the android target with one of the supported ABI descriptions. Again the dependencies are automatically build.

$ make android ANDROID_APP_ABI=<arch>
...

Were <arch> can be:

  • armeabi
  • armeabi-v7a (default)
  • arm64-v8a
  • x86
  • x86_64

Android specific flags

Flag Options Description
ANDROID_DEBUG_ENABLED true, false (default: false) Enable Android debug builds
ANDROID_APP_ABI armeabi, armeabi-v7a, arm64-v8a, x86, x86_64 (default: armeabi-v7a) Target CPU
ANDROID_WITH_PTRACE true, false (default: true) 1 Fuzzing engine backend architecture
ANDROID_API android-21, android-22, ... (default: android-26) 2 Target Android API
ANDROID_CLANG true, false (default: true) Android NDK compiler toolchain to use

1) If false, POSIX signals interface is used instead of PTRACE API

2) Due to bionic incompatibilities, only APIs >= 21 are supported