// Copyright 2020 Google LLC. All Rights Reserved.

#include "crypto_utils/aes_cbc_decryptor.h"

#include <cstdint>
#include <vector>

#include "testing/include/gmock/gmock.h"
#include "testing/include/gtest/gtest.h"

using ::testing::ElementsAreArray;

namespace widevine {

TEST(AesCbcDecryptorTest, NistTestCase) {
  // NIST SP 800-38A test vector F.2.1 CBC-AES128.Encrypt.
  static const uint8_t kAesCbcKey[] = {0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae,
                                       0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88,
                                       0x09, 0xcf, 0x4f, 0x3c};
  static const uint8_t kAesCbcIv[] = {0x00, 0x01, 0x02, 0x03, 0x04, 0x05,
                                      0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
                                      0x0c, 0x0d, 0x0e, 0x0f};
  static const uint8_t kAesCbcPlaintext[] = {
      // Block #1
      0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11,
      0x73, 0x93, 0x17, 0x2a,
      // Block #2
      0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac,
      0x45, 0xaf, 0x8e, 0x51,
      // Block #3
      0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19,
      0x1a, 0x0a, 0x52, 0xef,
      // Block #4
      0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b,
      0xe6, 0x6c, 0x37, 0x10};
  static const uint8_t kAesCbcCiphertext[] = {
      // Block #1
      0x76, 0x49, 0xab, 0xac, 0x81, 0x19, 0xb2, 0x46, 0xce, 0xe9, 0x8e, 0x9b,
      0x12, 0xe9, 0x19, 0x7d,
      // Block #2
      0x50, 0x86, 0xcb, 0x9b, 0x50, 0x72, 0x19, 0xee, 0x95, 0xdb, 0x11, 0x3a,
      0x91, 0x76, 0x78, 0xb2,
      // Block #3
      0x73, 0xbe, 0xd6, 0xb8, 0xe3, 0xc1, 0x74, 0x3b, 0x71, 0x16, 0xe6, 0x9e,
      0x22, 0x22, 0x95, 0x16,
      // Block #4
      0x3f, 0xf1, 0xca, 0xa1, 0x68, 0x1f, 0xac, 0x09, 0x12, 0x0e, 0xca, 0x30,
      0x75, 0x86, 0xe1, 0xa7};

  AesCbcDecryptor decryptor;
  ASSERT_TRUE(decryptor.SetKey(kAesCbcKey, sizeof(kAesCbcKey)));

  std::vector<uint8_t> output(sizeof(kAesCbcCiphertext));
  ASSERT_TRUE(decryptor.Decrypt(kAesCbcIv, sizeof(kAesCbcIv), kAesCbcCiphertext,
                                sizeof(kAesCbcCiphertext), output.data()));
  EXPECT_THAT(output,
              ElementsAreArray(kAesCbcPlaintext, sizeof(kAesCbcPlaintext)));
}

TEST(AesCbcEncryptorTest, NistTestCase2) {
  // NIST SP 800-38A test vector F.2.1 CBC-AES128.Encrypt.
  static const uint8_t kAesCbcKey[] = {
      0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
      0x38, 0x39, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46,
  };
  static const uint8_t kAesCbcIv[] = {
      0x2B, 0x70, 0xA4, 0xB5, 0xC2, 0x67, 0x8F, 0xD7,
      0xEC, 0x75, 0xB6, 0x44, 0xE8, 0xC7, 0x6A, 0x2B,
  };
  static const uint8_t kAesCbcPlaintext[] = {
      0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x41,
      0x42, 0x43, 0x44, 0x45, 0x46, 1,    2,    3,    4,    5,    6,
      7,    8,    9,    10,   11,   12,   13,   14,   15,   16,
  };
  static const uint8_t kAesCbcCiphertext[] = {
      0xF5, 0x9B, 0x16, 0x1F, 0x4B, 0xBC, 0x45, 0xC5, 0x16, 0x02, 0x25,
      0xD3, 0x7D, 0xDA, 0x22, 0xF4, 0xA7, 0x5D, 0x5F, 0x1A, 0x75, 0x2A,
      0xD0, 0xFF, 0x4C, 0x78, 0x7E, 0x2B, 0x36, 0x37, 0xC1, 0x7F,
  };

  AesCbcDecryptor decryptor;
  ASSERT_TRUE(decryptor.SetKey(kAesCbcKey, sizeof(kAesCbcKey)));

  std::vector<uint8_t> output(sizeof(kAesCbcPlaintext));
  ASSERT_TRUE(decryptor.Decrypt(kAesCbcIv, sizeof(kAesCbcIv), kAesCbcCiphertext,
                                sizeof(kAesCbcCiphertext), output.data()));
  EXPECT_THAT(output,
              ElementsAreArray(kAesCbcPlaintext, sizeof(kAesCbcPlaintext)));
}

}  // namespace widevine