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// Copyright 2018 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Fuzzer for the TPM2 and vendor specific Cr50 commands.
#include <unistd.h>
#include <cstdint>
#include <cstring>
#include <unordered_map>
#include <vector>
#include <src/libfuzzer/libfuzzer_macro.h>
#include <src/mutator.h>
#define HIDE_EC_STDLIB
#include "chip/host/persistence.h"
#include "fuzz/cr50_fuzz.pb.h"
#include "fuzz/fuzz_config.h"
#include "fuzz/pinweaver_model.h"
#include "fuzz/span.h"
#include "include/nvmem.h"
#include "include/nvmem_vars.h"
#include "include/pinweaver.h"
using protobuf_mutator::libfuzzer::LoadProtoInput;
namespace {
constexpr size_t kBufferAlignment = alignof(pw_request_t) >
alignof(pw_response_t)
? alignof(pw_request_t)
: alignof(pw_response_t);
} // namespace
extern "C" uint32_t nvmem_user_sizes[NVMEM_NUM_USERS] = {NVMEM_TPM_SIZE,
NVMEM_CR50_SIZE};
extern "C" void rand_bytes(void* data, size_t len) {
size_t x = 0;
uint8_t* buffer = reinterpret_cast<uint8_t*>(data);
for (; x < len; ++x) {
buffer[x] = rand();
}
}
extern "C" void get_storage_seed(void* buf, size_t* len) {
memset(buf, 0x77, *len);
}
extern "C" uint8_t get_current_pcr_digest(const uint8_t bitmask[2],
uint8_t sha256_of_selected_pcr[32]) {
memset(sha256_of_selected_pcr, 0, 32);
return 0;
}
// Needed for test targets to build.
extern "C" void run_test(void) {}
void InitializeFuzzerRun() {
memset(__host_flash, 0xff, sizeof(__host_flash));
nvmem_init();
nvmem_enable_commits();
initvars();
srand(0);
}
DEFINE_CUSTOM_PROTO_MUTATOR_IMPL(false, fuzz::Cr50FuzzerInput)
DEFINE_CUSTOM_PROTO_CROSSOVER_IMPL(false, fuzz::Cr50FuzzerInput)
extern "C" int test_fuzz_one_input(const uint8_t* data, unsigned int size) {
fuzz::Cr50FuzzerInput input;
if (!LoadProtoInput(false, data, size, &input)) {
return 0;
}
InitializeFuzzerRun();
PinweaverModel pinweaver_model;
alignas(kBufferAlignment) uint8_t buffer[PW_MAX_MESSAGE_SIZE] = {};
fuzz::span<uint8_t> buffer_view(buffer, sizeof(buffer));
for (const fuzz::Cr50SubAction& action : input.sub_actions()) {
switch (action.sub_action_case()) {
case fuzz::Cr50SubAction::kRandomBytes:
fuzz::CopyWithPadding(action.random_bytes().value(), buffer_view, 0);
pinweaver_model.SendBuffer(buffer_view);
break;
case fuzz::Cr50SubAction::kPinweaver:
pinweaver_model.ApplyRequest(action.pinweaver(), buffer_view);
break;
case fuzz::Cr50SubAction::SUB_ACTION_NOT_SET:
break;
}
}
return 0;
}
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