/* * Copyright (C) 2016 The Android Open Source Project * * 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 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include <assert.h> #include <stdint.h> #include <string.h> #include "expat.h" #include "siphash.h" // Macros to convert preprocessor macros to string literals. See // https://gcc.gnu.org/onlinedocs/gcc-3.4.3/cpp/Stringification.html #define xstr(s) str(s) #define str(s) #s // The encoder type that we wish to fuzz should come from the compile-time // definition `ENCODING_FOR_FUZZING`. This allows us to have a separate fuzzer // binary for #ifndef ENCODING_FOR_FUZZING # error "ENCODING_FOR_FUZZING was not provided to this fuzz target." #endif // 16-byte deterministic hash key. static unsigned char hash_key[16] = "FUZZING IS FUN!"; static void XMLCALL start(void *userData, const XML_Char *name, const XML_Char **atts) { (void)userData; (void)name; (void)atts; } static void XMLCALL end(void *userData, const XML_Char *name) { (void)userData; (void)name; } int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) { if (size == 0) return 0; XML_Parser p = XML_ParserCreate(xstr(ENCODING_FOR_FUZZING)); assert(p); XML_SetElementHandler(p, start, end); // Set the hash salt using siphash to generate a deterministic hash. struct sipkey *key = sip_keyof(hash_key); XML_SetHashSalt(p, (unsigned long)siphash24(data, size, key)); void *buf = XML_GetBuffer(p, size); assert(buf); memcpy(buf, data, size); XML_ParseBuffer(p, size, size == 0); XML_ParserFree(p); return 0; } |