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author | talos-vulndev <vulndev@cisco.com> | 2016-04-08 18:13:25 -0700 |
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committer | talos-vulndev <vulndev@cisco.com> | 2016-04-08 18:13:25 -0700 |
commit | 90ac6111c00d4d57d1f65e356f9c73e9eee8e3f8 (patch) | |
tree | ad7fce81e90c0f35af3ef7fa961ae8dd66bdbed7 /README.md | |
parent | eb5bf85c86ed788539758f54ff1a3c6b22af40c2 (diff) | |
download | afl-dyninst-90ac6111c00d4d57d1f65e356f9c73e9eee8e3f8.tar.gz |
README is txt
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diff --git a/README.md b/README.md deleted file mode 100644 index 6f5764a..0000000 --- a/README.md +++ /dev/null @@ -1,79 +0,0 @@ -American Fuzzy Lop + Dyninst == AFL Fuzzing blackbox binaries - -The tool has two parts. The instrumentation tool and the instrumentation -library. Instrumentation library has an initialization callback and basic -block callback functions which are designed to emulate what AFL is doing -with afl-gcc/afl-g++/afl-as. -Instrumentation tool (afl-dyninst) instruments the supplied binary by -inserting callbacks for each basic block and an initialization -callback either at _init or at specified entry point. - -Usage: ./afl-dyninst -i <binary> -o <binary> -l <library> -e <address> -s <number> - -i: Input binary - -o: Output binary - -l: Library to instrument (repeat for more than one) - -e: Entry point address to patch (required for stripped binaries) - -r: Runtime library to instrument (path to, repeat for more than one) - -s: Number of basic blocks to skip - -v: Verbose output - -Switch -l is used to supply the names of the libraries that should -be instrumented along the binary. Instrumented libraries will be copied -to the current working directory. This option can be repeated as many times -as needed. Depending on the environment, the LD_LIBRARY_PATH should be set -to point to instrumented libraries while fuzzing. - -Switch -e is used to manualy specify the entry point where initialization -callback is to be inserted. For unstipped binaries, afl-dyninst defaults -to using _init of the binary as an entry point. In case of stripped binaries -this option is required and is best set to the address of main which -can easily be determined by disassembling the binary and looking for an -argument to __libc_start_main. - -Switch -s instructs afl-dyninst to skip the first <number> of basic -blocks. Currently, it is used to work around a bug in Dyninst -but doubles as an optimization option, as skipping the basic blocks -of the initialization rutines makes things run faster. If the instrumented -binary is crashing by itself, try skiping a number of blocks. - -Switch -r allows you to specify a path to the library that is loaded -via dlopen() at runtime. Instrumented runtime libraries will be -written to the same location with a ".ins" suffix as not to overwrite -the original ones. Make sure to backup the originals and then rename the -instrumented ones to original name. - -The instrumentation library "libDyninst.so" must be available in the current working -directory as that is where the instrumented binary will be looking for it. - -Compiling: - -1. Edit the Makefile and set DYNINST_ROOT and AFL_ROOT to appropriate paths. -2. make - -Example of running the tool: - -Dyninst requires DYNINSTAPI_RT_LIB environment variable to point to the location -of libdyninstAPI_RT.so. - -$ export DYNINSTAPI_RT_LIB=/usr/local/lib/libdyninstAPI_RT.so -$ ./afl-dyninst -i ./rar -o ./rar_ins -e 0x4034c0 -s 100 -Skipping library: libAflDyninst.so -Instrumenting module: DEFAULT_MODULE -Inserting init callback. -Saving the instrumented binary to ./rar_ins... -All done! Happy fuzzing! - -Here we are instrumenting the rar binary with entrypoint at 0x4034c0 -(manualy found address of main), skipping the first 100 basic blocks -and outputing to rar_ins. - -Running AFL on instrumented binary - -Since AFL checks if the binary has been instrumented by afl-gcc,AFL_SKIP_BIN_CHECK environment -variable needs to be set. No modifications to AFL it self is needed. -$ export AFL_SKIP_BIN_CHECK=1 -Then, AFL can be run as usual: -$ afl-fuzz -i testcases/archives/common/gzip/ -o test_gzip -- ./gzip_ins -d -c - - - |