// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <string.h>
#include <string>

#include "butil/basictypes.h"
#include "butil/memory/scoped_ptr.h"
#include "butil/md5.h"
#include <gtest/gtest.h>

namespace butil {

TEST(MD5, DigestToBase16) {
  MD5Digest digest;

  int data[] = {
    0xd4, 0x1d, 0x8c, 0xd9,
    0x8f, 0x00, 0xb2, 0x04,
    0xe9, 0x80, 0x09, 0x98,
    0xec, 0xf8, 0x42, 0x7e
  };

  for (int i = 0; i < 16; ++i)
    digest.a[i] = data[i] & 0xff;

  std::string actual = MD5DigestToBase16(digest);
  std::string expected = "d41d8cd98f00b204e9800998ecf8427e";

  EXPECT_EQ(expected, actual);
}

TEST(MD5, MD5SumEmtpyData) {
  MD5Digest digest;
  const char* data = "";

  MD5Sum(data, strlen(data), &digest);

  int expected[] = {
    0xd4, 0x1d, 0x8c, 0xd9,
    0x8f, 0x00, 0xb2, 0x04,
    0xe9, 0x80, 0x09, 0x98,
    0xec, 0xf8, 0x42, 0x7e
  };

  for (int i = 0; i < 16; ++i)
    EXPECT_EQ(expected[i], digest.a[i] & 0xFF);
}

TEST(MD5, MD5SumOneByteData) {
  MD5Digest digest;
  const char* data = "a";

  MD5Sum(data, strlen(data), &digest);

  int expected[] = {
    0x0c, 0xc1, 0x75, 0xb9,
    0xc0, 0xf1, 0xb6, 0xa8,
    0x31, 0xc3, 0x99, 0xe2,
    0x69, 0x77, 0x26, 0x61
  };

  for (int i = 0; i < 16; ++i)
    EXPECT_EQ(expected[i], digest.a[i] & 0xFF);
}

TEST(MD5, MD5SumLongData) {
  const int length = 10 * 1024 * 1024 + 1;
  scoped_ptr<char[]> data(new char[length]);

  for (int i = 0; i < length; ++i)
    data[i] = i & 0xFF;

  MD5Digest digest;
  MD5Sum(data.get(), length, &digest);

  int expected[] = {
    0x90, 0xbd, 0x6a, 0xd9,
    0x0a, 0xce, 0xf5, 0xad,
    0xaa, 0x92, 0x20, 0x3e,
    0x21, 0xc7, 0xa1, 0x3e
  };

  for (int i = 0; i < 16; ++i)
    EXPECT_EQ(expected[i], digest.a[i] & 0xFF);
}

TEST(MD5, ContextWithEmptyData) {
  MD5Context ctx;
  MD5Init(&ctx);

  MD5Digest digest;
  MD5Final(&digest, &ctx);

  int expected[] = {
    0xd4, 0x1d, 0x8c, 0xd9,
    0x8f, 0x00, 0xb2, 0x04,
    0xe9, 0x80, 0x09, 0x98,
    0xec, 0xf8, 0x42, 0x7e
  };

  for (int i = 0; i < 16; ++i)
    EXPECT_EQ(expected[i], digest.a[i] & 0xFF);
}

TEST(MD5, ContextWithLongData) {
  MD5Context ctx;
  MD5Init(&ctx);

  const int length = 10 * 1024 * 1024 + 1;
  scoped_ptr<char[]> data(new char[length]);

  for (int i = 0; i < length; ++i)
    data[i] = i & 0xFF;

  int total = 0;
  while (total < length) {
    int len = 4097;  // intentionally not 2^k.
    if (len > length - total)
      len = length - total;

    MD5Update(&ctx,
              StringPiece(reinterpret_cast<char*>(data.get() + total), len));
    total += len;
  }

  EXPECT_EQ(length, total);

  MD5Digest digest;
  MD5Final(&digest, &ctx);

  int expected[] = {
    0x90, 0xbd, 0x6a, 0xd9,
    0x0a, 0xce, 0xf5, 0xad,
    0xaa, 0x92, 0x20, 0x3e,
    0x21, 0xc7, 0xa1, 0x3e
  };

  for (int i = 0; i < 16; ++i)
    EXPECT_EQ(expected[i], digest.a[i] & 0xFF);
}

// Example data from http://www.ietf.org/rfc/rfc1321.txt A.5 Test Suite
TEST(MD5, MD5StringTestSuite1) {
  std::string actual = MD5String("");
  std::string expected = "d41d8cd98f00b204e9800998ecf8427e";
  EXPECT_EQ(expected, actual);
}

TEST(MD5, MD5StringTestSuite2) {
  std::string actual = MD5String("a");
  std::string expected = "0cc175b9c0f1b6a831c399e269772661";
  EXPECT_EQ(expected, actual);
}

TEST(MD5, MD5StringTestSuite3) {
  std::string actual = MD5String("abc");
  std::string expected = "900150983cd24fb0d6963f7d28e17f72";
  EXPECT_EQ(expected, actual);
}

TEST(MD5, MD5StringTestSuite4) {
  std::string actual = MD5String("message digest");
  std::string expected = "f96b697d7cb7938d525a2f31aaf161d0";
  EXPECT_EQ(expected, actual);
}

TEST(MD5, MD5StringTestSuite5) {
  std::string actual = MD5String("abcdefghijklmnopqrstuvwxyz");
  std::string expected = "c3fcd3d76192e4007dfb496cca67e13b";
  EXPECT_EQ(expected, actual);
}

TEST(MD5, MD5StringTestSuite6) {
  std::string actual = MD5String("ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                                 "abcdefghijklmnopqrstuvwxyz"
                                 "0123456789");
  std::string expected = "d174ab98d277d9f5a5611c2c9f419d9f";
  EXPECT_EQ(expected, actual);
}

TEST(MD5, MD5StringTestSuite7) {
  std::string actual = MD5String("12345678901234567890"
                                 "12345678901234567890"
                                 "12345678901234567890"
                                 "12345678901234567890");
  std::string expected = "57edf4a22be3c955ac49da2e2107b67a";
  EXPECT_EQ(expected, actual);
}

TEST(MD5, ContextWithStringData) {
  MD5Context ctx;
  MD5Init(&ctx);

  MD5Update(&ctx, "abc");

  MD5Digest digest;
  MD5Final(&digest, &ctx);

  std::string actual = MD5DigestToBase16(digest);
  std::string expected = "900150983cd24fb0d6963f7d28e17f72";

  EXPECT_EQ(expected, actual);
}

// Test that a digest generated by MD5IntermediateFinal() gives the same results
// as an independently-calculated digest, and also does not modify the context.
TEST(MD5, IntermediateFinal) {
  // Independent context over the header.
  MD5Context check_header_context;
  MD5Init(&check_header_context);

  // Independent context over entire input.
  MD5Context check_full_context;
  MD5Init(&check_full_context);

  // Context intermediate digest will be calculated from.
  MD5Context context;
  MD5Init(&context);

  static const char kHeader[] = "header data";
  static const char kBody[] = "payload data";

  MD5Update(&context, kHeader);
  MD5Update(&check_header_context, kHeader);
  MD5Update(&check_full_context, kHeader);

  MD5Digest check_header_digest;
  MD5Final(&check_header_digest, &check_header_context);

  MD5Digest header_digest;
  MD5IntermediateFinal(&header_digest, &context);

  MD5Update(&context, kBody);
  MD5Update(&check_full_context, kBody);

  MD5Digest check_full_digest;
  MD5Final(&check_full_digest, &check_full_context);

  MD5Digest digest;
  MD5Final(&digest, &context);

  // The header and full digest pairs are the same, and they aren't the same as
  // each other.
  EXPECT_TRUE(!memcmp(&header_digest, &check_header_digest,
                      sizeof(header_digest)));
  EXPECT_TRUE(!memcmp(&digest, &check_full_digest, sizeof(digest)));
  EXPECT_FALSE(!memcmp(&digest, &header_digest, sizeof(digest)));
}

}  // namespace butil
