// Copyright 2010-2012, Google Inc.
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//
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#include <string>
#include <iostream>
#include "base/base.h"
#include "base/mmap.h"
#include "base/file_stream.h"
#include "base/encryptor.h"

DEFINE_string(password, "", "password");
DEFINE_string(salt, "", "salt");
DEFINE_string(iv, "", "initialization vector");

DEFINE_bool(encrypt, false, "encrypt mode");
DEFINE_bool(decrypt, false, "decrypt mode");

// encrypt/decrypt files
DEFINE_string(input_file, "", "input file");
DEFINE_string(output_file, "", "input file");

// perform encryption/decription with test_input.
// used for making a golden data for unittesting
DEFINE_string(test_input, "", "test input string");

namespace {
string Escape(const string &buf) {
  string tmp;
  mozc::Util::Escape(buf, &tmp);
  return tmp;
}
}  // namespace

int main(int argc, char **argv) {
  InitGoogle(argv[0], &argc, &argv, false);

  if (!FLAGS_iv.empty()) {
    CHECK_EQ(16, FLAGS_iv.size()) << "iv size must be 16 byte";
  }

  const uint8 *iv = FLAGS_iv.empty() ? NULL :
      reinterpret_cast<const uint8 *>(FLAGS_iv.data());

  if (!FLAGS_input_file.empty() && !FLAGS_output_file.empty()) {
    mozc::Encryptor::Key key;
    CHECK(key.DeriveFromPassword(FLAGS_password, FLAGS_salt, iv));

    mozc::Mmap<char> mmap;
    CHECK(mmap.Open(FLAGS_input_file.c_str(), "r"));
    string buf;
    buf.assign(mmap.begin(), mmap.GetFileSize());
    if (FLAGS_encrypt) {
      CHECK(mozc::Encryptor::EncryptString(key, &buf));
    } else if (FLAGS_decrypt) {
      CHECK(mozc::Encryptor::DecryptString(key, &buf));
    } else {
      LOG(FATAL) << "unknown mode. set --encrypt or --decrypt";
    }
    mozc::OutputFileStream ofs(FLAGS_output_file.c_str(), ios::binary);
    CHECK(ofs);
    ofs.write(buf.data(), buf.size());
  } else if (!FLAGS_test_input.empty()) {
    mozc::Encryptor::Key key1, key2;
    CHECK(key1.DeriveFromPassword(FLAGS_password, FLAGS_salt, iv));
    CHECK(key2.DeriveFromPassword(FLAGS_password, FLAGS_salt, iv));

    string buf = FLAGS_test_input;
    string iv_buf(reinterpret_cast<const char *>(key1.iv()), key1.iv_size());

    cout << "Password:  \"" << Escape(FLAGS_password) << "\"" << endl;
    cout << "Salt:      \"" << Escape(FLAGS_salt) << "\"" << endl;
    cout << "IV:        \"" << Escape(iv_buf) << "\"" << endl;
    cout << "Input:     \"" << Escape(buf) << "\"" << endl;
    CHECK(mozc::Encryptor::EncryptString(key1, &buf));
    cout << "Encrypted: \"" << Escape(buf) << "\"" << endl;
    CHECK(mozc::Encryptor::DecryptString(key2, &buf));
    cout << "Decrypted: \"" << Escape(buf) << "\"" << endl;
  } else {
    LOG(ERROR) <<
        "Unknown mode. set --input_file/--output_file/--test_input";
  }

  return 0;
}