// Copyright 2025 Google LLC

//

// 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 <cstdint>

#include <string>

#include "fuzzer/FuzzedDataProvider.h"

#include "fuzz_common.h"

#include "fuzz_js_format.h"

extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {

  FuzzedDataProvider fdp(data, size);

  // Use all remaining bytes as the message string

  const std::string message = fdp.ConsumeRemainingBytesAsString();

  // JS template to fuzz crypto signing/verifying using Node.js

  static constexpr std::string_view kTemplate = R"(

const crypto = require('crypto');

// Generate an RSA key pair (per fuzz run)

const { privateKey, publicKey } = crypto.generateKeyPairSync('rsa', {

  modulusLength: 2048

});

// The fuzzed message

const message = {0};

// --- SIGNING ---

try {

  const signer = crypto.createSign('SHA256');

  signer.update(message);

  signer.end();

  const signature = signer.sign(privateKey, 'base64');

  // --- VERIFYING ---

  const verifier = crypto.createVerify('SHA256');

  verifier.update(message);

  verifier.end();

  const isValid = verifier.verify(publicKey, signature, 'base64');

} catch (e) {

  // Catch errors to prevent harness crashes

}

)";

  // Inject the fuzzed message into the JS template

  const std::string js = FormatJs(kTemplate, ToSingleQuotedJsLiteral(message));

  // Execute the JavaScript under a Node isolate

  fuzz::IsolateScope iso;

  if (!iso.ok()) return 0;

  fuzz::RunEnvString(iso.isolate(), js.c_str());

  return 0;

}