// Copyright 2015 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 "net/der/parse_values.h"

#include <stdint.h>

#include "base/cxx17_backports.h"
#include "base/macros.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace net {
namespace der {
namespace test {

namespace {

template <size_t N>
Input FromStringLiteral(const char(&data)[N]) {
  // Strings are null-terminated. The null terminating byte shouldn't be
  // included in the Input, so the size is N - 1 instead of N.
  return Input(reinterpret_cast<const uint8_t*>(data), N - 1);
}

}  // namespace

TEST(ParseValuesTest, ParseBool) {
  uint8_t buf[] = {0xFF, 0x00};
  Input value(buf, 1);
  bool out;
  EXPECT_TRUE(ParseBool(value, &out));
  EXPECT_TRUE(out);

  buf[0] = 0;
  EXPECT_TRUE(ParseBool(value, &out));
  EXPECT_FALSE(out);

  buf[0] = 1;
  EXPECT_FALSE(ParseBool(value, &out));
  EXPECT_TRUE(ParseBoolRelaxed(value, &out));
  EXPECT_TRUE(out);

  buf[0] = 0xFF;
  value = Input(buf, 2);
  EXPECT_FALSE(ParseBool(value, &out));
  value = Input(buf, 0);
  EXPECT_FALSE(ParseBool(value, &out));
}

TEST(ParseValuesTest, ParseTimes) {
  GeneralizedTime out;

  EXPECT_TRUE(ParseUTCTime(FromStringLiteral("140218161200Z"), &out));

  // DER-encoded UTCTime must end with 'Z'.
  EXPECT_FALSE(ParseUTCTime(FromStringLiteral("140218161200X"), &out));

  // Check that a negative number (-4 in this case) doesn't get parsed as
  // a 2-digit number.
  EXPECT_FALSE(ParseUTCTime(FromStringLiteral("-40218161200Z"), &out));

  // Check that numbers with a leading 0 don't get parsed in octal by making
  // the second digit an invalid octal digit (e.g. 09).
  EXPECT_TRUE(ParseUTCTime(FromStringLiteral("090218161200Z"), &out));

  // Check that the length is validated.
  EXPECT_FALSE(ParseUTCTime(FromStringLiteral("140218161200"), &out));
  EXPECT_FALSE(ParseUTCTime(FromStringLiteral("140218161200Z0"), &out));
  EXPECT_FALSE(ParseUTCTimeRelaxed(FromStringLiteral("140218161200"), &out));
  EXPECT_FALSE(ParseUTCTimeRelaxed(FromStringLiteral("140218161200Z0"), &out));

  // Check strictness of UTCTime parsers.
  EXPECT_FALSE(ParseUTCTime(FromStringLiteral("1402181612Z"), &out));
  EXPECT_TRUE(ParseUTCTimeRelaxed(FromStringLiteral("1402181612Z"), &out));

  // Check that the time ends in Z.
  EXPECT_FALSE(ParseUTCTimeRelaxed(FromStringLiteral("1402181612Z0"), &out));

  // Check that ParseUTCTimeRelaxed calls ValidateGeneralizedTime.
  EXPECT_FALSE(ParseUTCTimeRelaxed(FromStringLiteral("1402181662Z"), &out));

  // Check format of GeneralizedTime.

  // Years 0 and 9999 are allowed.
  EXPECT_TRUE(ParseGeneralizedTime(FromStringLiteral("00000101000000Z"), &out));
  EXPECT_EQ(0, out.year);
  EXPECT_TRUE(ParseGeneralizedTime(FromStringLiteral("99991231235960Z"), &out));
  EXPECT_EQ(9999, out.year);

  // Leap seconds are allowed.
  EXPECT_TRUE(ParseGeneralizedTime(FromStringLiteral("20140218161260Z"), &out));

  // But nothing larger than a leap second.
  EXPECT_FALSE(
      ParseGeneralizedTime(FromStringLiteral("20140218161261Z"), &out));

  // Minutes only go up to 59.
  EXPECT_FALSE(
      ParseGeneralizedTime(FromStringLiteral("20140218166000Z"), &out));

  // Hours only go up to 23.
  EXPECT_FALSE(
      ParseGeneralizedTime(FromStringLiteral("20140218240000Z"), &out));
  // The 0th day of a month is invalid.
  EXPECT_FALSE(
      ParseGeneralizedTime(FromStringLiteral("20140200161200Z"), &out));
  // The 0th month is invalid.
  EXPECT_FALSE(
      ParseGeneralizedTime(FromStringLiteral("20140018161200Z"), &out));
  // Months greater than 12 are invalid.
  EXPECT_FALSE(
      ParseGeneralizedTime(FromStringLiteral("20141318161200Z"), &out));

  // Some months have 31 days.
  EXPECT_TRUE(ParseGeneralizedTime(FromStringLiteral("20140131000000Z"), &out));

  // September has only 30 days.
  EXPECT_FALSE(
      ParseGeneralizedTime(FromStringLiteral("20140931000000Z"), &out));

  // February has only 28 days...
  EXPECT_FALSE(
      ParseGeneralizedTime(FromStringLiteral("20140229000000Z"), &out));

  // ... unless it's a leap year.
  EXPECT_TRUE(ParseGeneralizedTime(FromStringLiteral("20160229000000Z"), &out));

  // There aren't any leap days in years divisible by 100...
  EXPECT_FALSE(
      ParseGeneralizedTime(FromStringLiteral("21000229000000Z"), &out));

  // ...unless it's also divisible by 400.
  EXPECT_TRUE(ParseGeneralizedTime(FromStringLiteral("20000229000000Z"), &out));

  // Check more perverse invalid inputs.

  // Check that trailing null bytes are not ignored.
  EXPECT_FALSE(
      ParseGeneralizedTime(FromStringLiteral("20001231010203Z\0"), &out));

  // Check what happens when a null byte is in the middle of the input.
  EXPECT_FALSE(ParseGeneralizedTime(FromStringLiteral(
                                        "200\0"
                                        "1231010203Z"),
                                    &out));

  // The year can't be in hex.
  EXPECT_FALSE(
      ParseGeneralizedTime(FromStringLiteral("0x201231000000Z"), &out));

  // The last byte must be 'Z'.
  EXPECT_FALSE(
      ParseGeneralizedTime(FromStringLiteral("20001231000000X"), &out));

  // Check that the length is validated.
  EXPECT_FALSE(ParseGeneralizedTime(FromStringLiteral("20140218161200"), &out));
  EXPECT_FALSE(
      ParseGeneralizedTime(FromStringLiteral("20140218161200Z0"), &out));
}

TEST(ParseValuesTest, TimesCompare) {
  GeneralizedTime time1;
  GeneralizedTime time2;
  GeneralizedTime time3;
  GeneralizedTime time4;

  ASSERT_TRUE(
      ParseGeneralizedTime(FromStringLiteral("20140218161200Z"), &time1));
  // Test that ParseUTCTime correctly normalizes the year.
  ASSERT_TRUE(ParseUTCTime(FromStringLiteral("150218161200Z"), &time2));
  ASSERT_TRUE(ParseUTCTimeRelaxed(FromStringLiteral("1503070000Z"), &time3));
  ASSERT_TRUE(
      ParseGeneralizedTime(FromStringLiteral("20160218161200Z"), &time4));
  EXPECT_TRUE(time1 < time2);
  EXPECT_TRUE(time2 < time3);
  EXPECT_TRUE(time3 < time4);

  EXPECT_TRUE(time2 > time1);
  EXPECT_TRUE(time2 >= time1);
  EXPECT_TRUE(time3 <= time4);
  EXPECT_TRUE(time1 <= time1);
  EXPECT_TRUE(time1 >= time1);
}

TEST(ParseValuesTest, UTCTimeRange) {
  GeneralizedTime time;
  ASSERT_TRUE(
      ParseGeneralizedTime(FromStringLiteral("20140218161200Z"), &time));
  EXPECT_TRUE(time.InUTCTimeRange());

  time.year = 1950;
  EXPECT_TRUE(time.InUTCTimeRange());

  time.year = 1949;
  EXPECT_FALSE(time.InUTCTimeRange());

  time.year = 2049;
  EXPECT_TRUE(time.InUTCTimeRange());

  time.year = 2050;
  EXPECT_FALSE(time.InUTCTimeRange());
}

struct Uint64TestData {
  bool should_pass;
  const uint8_t input[9];
  size_t length;
  uint64_t expected_value;
};

const Uint64TestData kUint64TestData[] = {
    {true, {0x00}, 1, 0},
    // This number fails because it is not a minimal representation.
    {false, {0x00, 0x00}, 2},
    {true, {0x01}, 1, 1},
    {false, {0xFF}, 1},
    {true, {0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}, 8, INT64_MAX},
    {true,
     {0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
     9,
     UINT64_MAX},
    // This number fails because it is negative.
    {false, {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}, 8},
    {false, {0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}, 8},
    {false, {0x00, 0x01}, 2},
    {false, {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09}, 9},
    {false, {0}, 0},
};

TEST(ParseValuesTest, ParseUint64) {
  for (size_t i = 0; i < base::size(kUint64TestData); i++) {
    const Uint64TestData& test_case = kUint64TestData[i];
    SCOPED_TRACE(i);

    uint64_t result;
    EXPECT_EQ(test_case.should_pass,
              ParseUint64(Input(test_case.input, test_case.length), &result));
    if (test_case.should_pass)
      EXPECT_EQ(test_case.expected_value, result);
  }
}

struct Uint8TestData {
  bool should_pass;
  const uint8_t input[9];
  size_t length;
  uint8_t expected_value;
};

const Uint8TestData kUint8TestData[] = {
    {true, {0x00}, 1, 0},
    // This number fails because it is not a minimal representation.
    {false, {0x00, 0x00}, 2},
    {true, {0x01}, 1, 1},
    {false, {0x01, 0xFF}, 2},
    {false, {0x03, 0x83}, 2},
    {true, {0x7F}, 1, 0x7F},
    {true, {0x00, 0xFF}, 2, 0xFF},
    // This number fails because it is negative.
    {false, {0xFF}, 1},
    {false, {0x80}, 1},
    {false, {0x00, 0x01}, 2},
    {false, {0}, 0},
};

TEST(ParseValuesTest, ParseUint8) {
  for (size_t i = 0; i < base::size(kUint8TestData); i++) {
    const Uint8TestData& test_case = kUint8TestData[i];
    SCOPED_TRACE(i);

    uint8_t result;
    EXPECT_EQ(test_case.should_pass,
              ParseUint8(Input(test_case.input, test_case.length), &result));
    if (test_case.should_pass)
      EXPECT_EQ(test_case.expected_value, result);
  }
}

struct IsValidIntegerTestData {
  bool should_pass;
  const uint8_t input[2];
  size_t length;
  bool negative;
};

const IsValidIntegerTestData kIsValidIntegerTestData[] = {
    // Empty input (invalid DER).
    {false, {0x00}, 0},

    // The correct encoding for zero.
    {true, {0x00}, 1, false},

    // Invalid representation of zero (not minimal)
    {false, {0x00, 0x00}, 2},

    // Valid single byte negative numbers.
    {true, {0x80}, 1, true},
    {true, {0xFF}, 1, true},

    // Non-minimal negative number.
    {false, {0xFF, 0x80}, 2},

    // Positive number with a legitimate leading zero.
    {true, {0x00, 0x80}, 2, false},

    // A legitimate negative number that starts with FF (MSB of second byte is
    // 0 so OK).
    {true, {0xFF, 0x7F}, 2, true},
};

TEST(ParseValuesTest, IsValidInteger) {
  for (size_t i = 0; i < base::size(kIsValidIntegerTestData); i++) {
    const auto& test_case = kIsValidIntegerTestData[i];
    SCOPED_TRACE(i);

    bool negative;
    EXPECT_EQ(
        test_case.should_pass,
        IsValidInteger(Input(test_case.input, test_case.length), &negative));
    if (test_case.should_pass)
      EXPECT_EQ(test_case.negative, negative);
  }
}

// Tests parsing an empty BIT STRING.
TEST(ParseValuesTest, ParseBitStringEmptyNoUnusedBits) {
  const uint8_t kData[] = {0x00};

  BitString bit_string;
  ASSERT_TRUE(ParseBitString(Input(kData), &bit_string));

  EXPECT_EQ(0u, bit_string.unused_bits());
  EXPECT_EQ(0u, bit_string.bytes().Length());

  EXPECT_FALSE(bit_string.AssertsBit(0));
  EXPECT_FALSE(bit_string.AssertsBit(1));
  EXPECT_FALSE(bit_string.AssertsBit(3));
}

// Tests parsing an empty BIT STRING that incorrectly claims one unused bit.
TEST(ParseValuesTest, ParseBitStringEmptyOneUnusedBit) {
  const uint8_t kData[] = {0x01};

  BitString bit_string;
  EXPECT_FALSE(ParseBitString(Input(kData), &bit_string));
}

// Tests parsing an empty BIT STRING that is not minmally encoded (the entire
// last byte is comprised of unused bits).
TEST(ParseValuesTest, ParseBitStringNonEmptyTooManyUnusedBits) {
  const uint8_t kData[] = {0x08, 0x00};

  BitString bit_string;
  EXPECT_FALSE(ParseBitString(Input(kData), &bit_string));
}

// Tests parsing a BIT STRING of 7 bits each of which are 1.
TEST(ParseValuesTest, ParseBitStringSevenOneBits) {
  const uint8_t kData[] = {0x01, 0xFE};

  BitString bit_string;
  ASSERT_TRUE(ParseBitString(Input(kData), &bit_string));

  EXPECT_EQ(1u, bit_string.unused_bits());
  EXPECT_EQ(1u, bit_string.bytes().Length());
  EXPECT_EQ(0xFE, bit_string.bytes().UnsafeData()[0]);

  EXPECT_TRUE(bit_string.AssertsBit(0));
  EXPECT_TRUE(bit_string.AssertsBit(1));
  EXPECT_TRUE(bit_string.AssertsBit(2));
  EXPECT_TRUE(bit_string.AssertsBit(3));
  EXPECT_TRUE(bit_string.AssertsBit(4));
  EXPECT_TRUE(bit_string.AssertsBit(5));
  EXPECT_TRUE(bit_string.AssertsBit(6));
  EXPECT_FALSE(bit_string.AssertsBit(7));
  EXPECT_FALSE(bit_string.AssertsBit(8));
}

// Tests parsing a BIT STRING of 7 bits each of which are 1. The unused bit
// however is set to 1, which is an invalid encoding.
TEST(ParseValuesTest, ParseBitStringSevenOneBitsUnusedBitIsOne) {
  const uint8_t kData[] = {0x01, 0xFF};

  BitString bit_string;
  EXPECT_FALSE(ParseBitString(Input(kData), &bit_string));
}

}  // namespace test
}  // namespace der
}  // namespace net