mirror of
https://github.com/nlohmann/json.git
synced 2024-12-30 09:07:51 +08:00
41 lines
1.2 KiB
C++
41 lines
1.2 KiB
C++
|
// This file is distributed under the University of Illinois Open Source
|
||
|
|
// License. See LICENSE.TXT for details.
|
||
|
|
|
||
|
|
// This test computes a checksum of the data (all but the last 4 bytes),
|
||
|
|
// and then compares the last 4 bytes with the computed value.
|
||
|
|
// A fuzzer with cmp traces is expected to defeat this check.
|
||
|
|
#include <cstdint>
|
||
|
|
#include <cstdlib>
|
||
|
|
#include <cstring>
|
||
|
|
#include <cstdio>
|
||
|
|
|
||
|
|
// A modified jenkins_one_at_a_time_hash initialized by non-zero,
|
||
|
|
// so that simple_hash(0) != 0. See also
|
||
|
|
// https://en.wikipedia.org/wiki/Jenkins_hash_function
|
||
|
|
static uint32_t simple_hash(const uint8_t *Data, size_t Size) {
|
||
|
|
uint32_t Hash = 0x12039854;
|
||
|
|
for (uint32_t i = 0; i < Size; i++) {
|
||
|
|
Hash += Data[i];
|
||
|
|
Hash += (Hash << 10);
|
||
|
|
Hash ^= (Hash >> 6);
|
||
|
|
}
|
||
|
|
Hash += (Hash << 3);
|
||
|
|
Hash ^= (Hash >> 11);
|
||
|
|
Hash += (Hash << 15);
|
||
|
|
return Hash;
|
||
|
|
}
|
||
|
|
|
||
|
|
extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
|
||
|
|
if (Size < 14)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
uint32_t Hash = simple_hash(&Data[0], Size - 4);
|
||
|
|
uint32_t Want = reinterpret_cast<const uint32_t *>(&Data[Size - 4])[0];
|
||
|
|
if (Hash != Want)
|
||
|
|
return 0;
|
||
|
|
fprintf(stderr, "BINGO; simple_hash defeated: %x == %x\n", (unsigned int)Hash,
|
||
|
|
(unsigned int)Want);
|
||
|
|
exit(1);
|
||
|
|
return 0;
|
||
|
|
}
|