android/libwvdrmengine/oemcrypto/test/fuzz_tests/oemcrypto_generic_decrypt_fuzz.cc

// Copyright 2020 Google LLC. All Rights Reserved. This file and proprietary
// source code may only be used and distributed under the Widevine
// License Agreement.

#include "FuzzedDataProvider.h"
#include "OEMCryptoCENC.h"
#include "log.h"
#include "oemcrypto_fuzz_helper.h"
#include "oemcrypto_fuzz_structs.h"
#include "oemcrypto_types.h"

namespace wvoec {
extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
  // Redirect printf and log statements from oemcrypto functions to a file to
  // reduce noise
  RedirectStdoutToFile();

  // Split data using separator.
  const std::vector<FuzzedData> inputs = SplitFuzzedData(data, size);
  if (inputs.size() < 2) {
    return 0;
  }

  OEMCrypto_Generic_Api_Fuzz fuzzed_structure;
  if (inputs[0].size < sizeof(fuzzed_structure)) {
    return 0;
  }
  // Copy OEMCrypto_Generic_Api_Fuzz from input data.
  FuzzedDataProvider fuzzed_data(inputs[0].data, inputs[0].size);
  fuzzed_data.ConsumeData(&fuzzed_structure, sizeof(fuzzed_structure));
  ConvertDataToValidEnum(OEMCrypto_CipherMode_MaxValue,
                         &fuzzed_structure.cipher_mode);
  ConvertDataToValidEnum(OEMCrypto_Algorithm_MaxValue,
                         &fuzzed_structure.algorithm);
  // Copy iv from input data.
  const std::vector<uint8_t> iv = fuzzed_data.ConsumeRemainingBytes<uint8_t>();

  // Initialize encrypted and clear buffers.
  const std::vector<uint8_t> encrypted_buffer(inputs[1].data,
                                              inputs[1].data + inputs[1].size);
  std::vector<uint8_t> clear_buffer(encrypted_buffer.size());

  OEMCryptoLicenseAPIFuzz license_api_fuzz;
  Session* session = license_api_fuzz.session();
  // Load license and call generic_decrypt API.
  license_api_fuzz.LoadLicense();
  OEMCryptoResult sts = OEMCrypto_SelectKey(
      session->session_id(), session->license().keys[0].key_id,
      session->license().keys[0].key_id_length, fuzzed_structure.cipher_mode);
  CheckStatusAndExitFuzzerOnFailure(sts, OEMCrypto_SUCCESS);
  OEMCrypto_Generic_Decrypt(session->session_id(), encrypted_buffer.data(),
                            encrypted_buffer.size(), iv.data(),
                            fuzzed_structure.algorithm, clear_buffer.data());
  return 0;
}
}  // namespace wvoec