mirror of https://github.com/mstorsjo/fdk-aac.git
60 lines
1.8 KiB
Markdown
60 lines
1.8 KiB
Markdown
# Fuzzer for libFraunhoferAAC decoder
|
|
|
|
## Plugin Design Considerations
|
|
The fuzzer plugin for aac decoder is designed based on the understanding of the
|
|
codec and tries to achieve the following:
|
|
|
|
##### Maximize code coverage
|
|
|
|
This fuzzer makes use of the following config parameters:
|
|
1. Transport type (parameter name: `TRANSPORT_TYPE`)
|
|
|
|
| Parameter| Valid Values| Configured Value|
|
|
|------------- |-------------| ----- |
|
|
| `TRANSPORT_TYPE` | 0.`TT_UNKNOWN ` 1.`TT_MP4_RAW ` 2.`TT_MP4_ADIF ` 3.`TT_MP4_ADTS ` 4.`TT_MP4_LATM_MCP1 ` 5.`TT_MP4_LATM_MCP0 ` 6.`TT_MP4_LOAS ` 7.`TT_DRM ` | `TT_MP4_ADIF ` |
|
|
|
|
Note: Value of `TRANSPORT_TYPE` could be set to any of these values.
|
|
It is set to `TT_MP4_ADIF` in the fuzzer plugin.
|
|
|
|
##### Maximize utilization of input data
|
|
The plugin feeds the entire input data to the codec using a loop.
|
|
* If the decode operation was successful, the input is advanced by an
|
|
offset calculated using valid bytes.
|
|
* If the decode operation was un-successful, the input is advanced by 1 byte
|
|
till it reaches a valid frame or end of stream.
|
|
|
|
This ensures that the plugin tolerates any kind of input (empty, huge,
|
|
malformed, etc) and doesnt `exit()` on any input and thereby increasing the
|
|
chance of identifying vulnerabilities.
|
|
|
|
## Build
|
|
|
|
This describes steps to build aac_dec_fuzzer binary.
|
|
|
|
## Android
|
|
|
|
### Steps to build
|
|
Build the fuzzer
|
|
```
|
|
$ mm -j$(nproc) aac_dec_fuzzer
|
|
```
|
|
|
|
### Steps to run
|
|
Create a directory CORPUS_DIR and copy some aac files to that folder.
|
|
Push this directory to device.
|
|
|
|
To run on device
|
|
```
|
|
$ adb sync data
|
|
$ adb shell /data/fuzz/arm64/aac_dec_fuzzer/aac_dec_fuzzer CORPUS_DIR
|
|
```
|
|
To run on host
|
|
```
|
|
$ $ANDROID_HOST_OUT/fuzz/x86_64/aac_dec_fuzzer/aac_dec_fuzzer CORPUS_DIR
|
|
```
|
|
|
|
## References:
|
|
* http://llvm.org/docs/LibFuzzer.html
|
|
* https://github.com/google/oss-fuzz
|
|
|