// Copyright 2023 The ChromiumOS Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "cryptohome/crc.h"

#include <stdint.h>
#include <vector>

#include <gmock/gmock.h>
#include <gtest/gtest.h>

namespace cryptohome {
namespace {

using ::testing::Eq;

// Various spot check tests for a few different CRC8 values. This is not
// intended to be comprehensive.
TEST(Crc8Test, Empty) {
  // We don't actually use the stored value here, but C++ does not allow
  // zero-length arrays.
  const char kData[] = {0};
  EXPECT_THAT(Crc8(kData, 0), Eq(0));
}

TEST(Crc8Test, ZeroArray) {
  const char kData[] = {0, 0, 0, 0, 0, 0, 0, 0};
  EXPECT_THAT(Crc8(kData, sizeof(kData)), Eq(0));
}

TEST(Crc8Test, SomeBytes) {
  const char kData[] = {1, 2, 3, 4, 5, 6, 7, 8};
  EXPECT_THAT(Crc8(kData, sizeof(kData)), Eq(0x3e));
}

TEST(Crc8Test, MoreBytes) {
  const char kData[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16};
  EXPECT_THAT(Crc8(kData, sizeof(kData)), Eq(0xb0));
}

TEST(Crc8Test, AllOnes) {
  const unsigned char kData[] = {0xff, 0xff, 0xff, 0xff,
                                 0xff, 0xff, 0xff, 0xff};
  EXPECT_THAT(Crc8(kData, sizeof(kData)), Eq(0xd7));
}

// TODO(b/168049518): Move to libchrome.
TEST(Crc32Test, TestVector1) {
  const std::vector<uint8_t> data = {0x00, 0x00, 0x00, 0x00,
                                     0x00, 0x00, 0x00, 0x00};
  uint32_t sum = Crc32(data.data(), data.size());
  EXPECT_EQ(sum, 0x6522DF69);
}

TEST(Crc32Test, TestVector2) {
  const std::vector<uint8_t> data = {0xFF, 0xFF, 0xFF, 0xFF,
                                     0xFF, 0xFF, 0xFF, 0xFF};
  uint32_t sum = Crc32(data.data(), data.size());
  EXPECT_EQ(sum, 0x2144DF1C);
}

TEST(Crc32Test, TestVector3) {
  const std::vector<uint8_t> data = {
      0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A,
      0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15,
      0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F};
  uint32_t sum = Crc32(data.data(), data.size());
  EXPECT_EQ(sum, 0x91267E8A);
}

TEST(Crc32Test, TestVector4) {
  const std::vector<uint8_t> data = {
      0x1F, 0x1E, 0x1D, 0x1C, 0x1B, 0x1A, 0x19, 0x18, 0x17, 0x16, 0x15,
      0x14, 0x13, 0x12, 0x11, 0x10, 0x0F, 0x0E, 0x0D, 0x0C, 0x0B, 0x0A,
      0x09, 0x08, 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00};
  uint32_t sum = Crc32(data.data(), data.size());
  EXPECT_EQ(sum, 0x9AB0EF72);
}

}  // namespace
}  // namespace cryptohome