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/*
american fuzzy lop - fuzzer code
--------------------------------
Written and maintained by Michal Zalewski <lcamtuf@google.com>
Forkserver design by Jann Horn <jannhorn@googlemail.com>
Copyright 2013, 2014, 2015, 2016, 2017 Google Inc. All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at:
http://www.apache.org/licenses/LICENSE-2.0
This is the real deal: the program takes an instrumented binary and
attempts a variety of basic fuzzing tricks, paying close attention to
how they affect the execution path.
*/
#include "afl-fuzz.h"
/* Python stuff */
#ifdef USE_PYTHON
int init_py() {
Py_Initialize();
u8* module_name = getenv("AFL_PYTHON_MODULE");
if (module_name) {
PyObject* py_name = PyString_FromString(module_name);
py_module = PyImport_Import(py_name);
Py_DECREF(py_name);
if (py_module != NULL) {
u8 py_notrim = 0;
py_functions[PY_FUNC_INIT] = PyObject_GetAttrString(py_module, "init");
py_functions[PY_FUNC_FUZZ] = PyObject_GetAttrString(py_module, "fuzz");
py_functions[PY_FUNC_INIT_TRIM] = PyObject_GetAttrString(py_module, "init_trim");
py_functions[PY_FUNC_POST_TRIM] = PyObject_GetAttrString(py_module, "post_trim");
py_functions[PY_FUNC_TRIM] = PyObject_GetAttrString(py_module, "trim");
for (u8 py_idx = 0; py_idx < PY_FUNC_COUNT; ++py_idx) {
if (!py_functions[py_idx] || !PyCallable_Check(py_functions[py_idx])) {
if (py_idx >= PY_FUNC_INIT_TRIM && py_idx <= PY_FUNC_TRIM) {
// Implementing the trim API is optional for now
if (PyErr_Occurred())
PyErr_Print();
py_notrim = 1;
} else {
if (PyErr_Occurred())
PyErr_Print();
fprintf(stderr, "Cannot find/call function with index %d in external Python module.\n", py_idx);
return 1;
}
}
}
if (py_notrim) {
py_functions[PY_FUNC_INIT_TRIM] = NULL;
py_functions[PY_FUNC_POST_TRIM] = NULL;
py_functions[PY_FUNC_TRIM] = NULL;
WARNF("Python module does not implement trim API, standard trimming will be used.");
}
PyObject *py_args, *py_value;
/* Provide the init function a seed for the Python RNG */
py_args = PyTuple_New(1);
py_value = PyInt_FromLong(UR(0xFFFFFFFF));
if (!py_value) {
Py_DECREF(py_args);
fprintf(stderr, "Cannot convert argument\n");
return 1;
}
PyTuple_SetItem(py_args, 0, py_value);
py_value = PyObject_CallObject(py_functions[PY_FUNC_INIT], py_args);
Py_DECREF(py_args);
if (py_value == NULL) {
PyErr_Print();
fprintf(stderr,"Call failed\n");
return 1;
}
} else {
PyErr_Print();
fprintf(stderr, "Failed to load \"%s\"\n", module_name);
return 1;
}
}
return 0;
}
void finalize_py() {
if (py_module != NULL) {
u32 i;
for (i = 0; i < PY_FUNC_COUNT; ++i)
Py_XDECREF(py_functions[i]);
Py_DECREF(py_module);
}
Py_Finalize();
}
void fuzz_py(char* buf, size_t buflen, char* add_buf, size_t add_buflen, char** ret, size_t* retlen) {
if (py_module != NULL) {
PyObject *py_args, *py_value;
py_args = PyTuple_New(2);
py_value = PyByteArray_FromStringAndSize(buf, buflen);
if (!py_value) {
Py_DECREF(py_args);
fprintf(stderr, "Cannot convert argument\n");
return;
}
PyTuple_SetItem(py_args, 0, py_value);
py_value = PyByteArray_FromStringAndSize(add_buf, add_buflen);
if (!py_value) {
Py_DECREF(py_args);
fprintf(stderr, "Cannot convert argument\n");
return;
}
PyTuple_SetItem(py_args, 1, py_value);
py_value = PyObject_CallObject(py_functions[PY_FUNC_FUZZ], py_args);
Py_DECREF(py_args);
if (py_value != NULL) {
*retlen = PyByteArray_Size(py_value);
*ret = malloc(*retlen);
memcpy(*ret, PyByteArray_AsString(py_value), *retlen);
Py_DECREF(py_value);
} else {
PyErr_Print();
fprintf(stderr,"Call failed\n");
return;
}
}
}
u32 init_trim_py(char* buf, size_t buflen) {
PyObject *py_args, *py_value;
py_args = PyTuple_New(1);
py_value = PyByteArray_FromStringAndSize(buf, buflen);
if (!py_value) {
Py_DECREF(py_args);
FATAL("Failed to convert arguments");
}
PyTuple_SetItem(py_args, 0, py_value);
py_value = PyObject_CallObject(py_functions[PY_FUNC_INIT_TRIM], py_args);
Py_DECREF(py_args);
if (py_value != NULL) {
u32 retcnt = PyInt_AsLong(py_value);
Py_DECREF(py_value);
return retcnt;
} else {
PyErr_Print();
FATAL("Call failed");
}
}
u32 post_trim_py(char success) {
PyObject *py_args, *py_value;
py_args = PyTuple_New(1);
py_value = PyBool_FromLong(success);
if (!py_value) {
Py_DECREF(py_args);
FATAL("Failed to convert arguments");
}
PyTuple_SetItem(py_args, 0, py_value);
py_value = PyObject_CallObject(py_functions[PY_FUNC_POST_TRIM], py_args);
Py_DECREF(py_args);
if (py_value != NULL) {
u32 retcnt = PyInt_AsLong(py_value);
Py_DECREF(py_value);
return retcnt;
} else {
PyErr_Print();
FATAL("Call failed");
}
}
void trim_py(char** ret, size_t* retlen) {
PyObject *py_args, *py_value;
py_args = PyTuple_New(0);
py_value = PyObject_CallObject(py_functions[PY_FUNC_TRIM], py_args);
Py_DECREF(py_args);
if (py_value != NULL) {
*retlen = PyByteArray_Size(py_value);
*ret = malloc(*retlen);
memcpy(*ret, PyByteArray_AsString(py_value), *retlen);
Py_DECREF(py_value);
} else {
PyErr_Print();
FATAL("Call failed");
}
}
#endif /* USE_PYTHON */
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