libexpat/expat/fuzz/xml_parsebuffer_fuzzer.c
2019-11-17 21:12:13 +01:00

67 lines
1.9 KiB
C

/*
* 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) {
}
static void XMLCALL
end(void *userData, const XML_Char *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;
}