mirror of
https://github.com/yuzu-emu/mbedtls.git
synced 2024-12-27 03:55:55 +00:00
5d46f6a89b
git grep -Fl /config.pl | xargs sed -i -e 's!/config\.pl!/config.py!g' Also: * Change one comment in include/mbedtls/check_config.h. * Change PERL to PYTHON in CMakeLists.txt.
69 lines
2.5 KiB
Markdown
69 lines
2.5 KiB
Markdown
What is it?
|
|
------
|
|
|
|
This directory contains fuzz targets.
|
|
Fuzz targets are simple codes using the library.
|
|
They are used with a so-called fuzz driver, which will generate inputs, try to process them with the fuzz target, and alert in case of an unwanted behavior (such as a buffer overflow for instance).
|
|
|
|
These targets were meant to be used with oss-fuzz but can be used in other contexts.
|
|
|
|
This code was contributed by Philippe Antoine ( Catena cyber ).
|
|
|
|
How to run?
|
|
------
|
|
|
|
To run the fuzz targets like oss-fuzz:
|
|
```
|
|
git clone https://github.com/google/oss-fuzz
|
|
cd oss-fuzz
|
|
python infra/helper.py build_image mbedtls
|
|
python infra/helper.py build_fuzzers --sanitizer address mbedtls
|
|
python infra/helper.py run_fuzzer mbedtls fuzz_client
|
|
```
|
|
You can use `undefined` sanitizer as well as `address` sanitizer.
|
|
And you can run any of the fuzz targets like `fuzz_client`.
|
|
|
|
To run the fuzz targets without oss-fuzz, you first need to install one libFuzzingEngine (libFuzzer for instance).
|
|
Then you need to compile the code with the compiler flags of the wished sanitizer.
|
|
```
|
|
perl scripts/config.py set MBEDTLS_PLATFORM_TIME_ALT
|
|
mkdir build
|
|
cd build
|
|
cmake ..
|
|
make
|
|
```
|
|
Finally, you can run the targets like `./test/fuzz/fuzz_client`.
|
|
|
|
|
|
Corpus generation for network trafic targets
|
|
------
|
|
|
|
These targets use network trafic as inputs :
|
|
* client : simulates a client against (fuzzed) server traffic
|
|
* server : simulates a server against (fuzzed) client traffic
|
|
* dtls_client
|
|
* dtls_server
|
|
|
|
They also use the last bytes as configuration options.
|
|
|
|
To generate corpus for these targets, you can do the following, not fully automated steps :
|
|
* Build mbedtls programs ssl_server2 and ssl_client2
|
|
* Run them one against the other with `reproducible` option turned on while capturing trafic into test.pcap
|
|
* Extract tcp payloads, for instance with tshark : `tshark -Tfields -e tcp.dstport -e tcp.payload -r test.pcap > test.txt`
|
|
* Run a dummy python script to output either client or server corpus file like `python dummy.py test.txt > test.cor`
|
|
* Finally, you can add the options by appending the last bytes to the file test.cor
|
|
|
|
Here is an example of dummy.py for extracting payload from client to server (if we used `tcp.dstport` in tshark command)
|
|
```
|
|
import sys
|
|
import binascii
|
|
|
|
f = open(sys.argv[1])
|
|
for l in f.readlines():
|
|
portAndPl=l.split()
|
|
if len(portAndPl) == 2:
|
|
# determine client or server based on port
|
|
if portAndPl[0] == "4433":
|
|
print(binascii.unhexlify(portAndPl[1].replace(":","")))
|
|
```
|