root/crypto/encryptor_unittest.cc

DEFINITIONS

1. TEST
2. TEST
3. TestAESCTREncrypt
4. TestAESCTRMultipleDecrypt
5. TEST
6. TEST
7. TEST
8. TEST
9. TEST
10. TEST
11. TEST
12. TEST
13. TEST
14. TEST
15. TEST
16. TEST
17. TEST

// Copyright (c) 2012 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 "crypto/encryptor.h"

#include <string>

#include "base/memory/scoped_ptr.h"
#include "base/strings/string_number_conversions.h"
#include "crypto/symmetric_key.h"
#include "testing/gtest/include/gtest/gtest.h"

TEST(EncryptorTest, EncryptDecrypt) {
  scoped_ptr<crypto::SymmetricKey> key(
      crypto::SymmetricKey::DeriveKeyFromPassword(
          crypto::SymmetricKey::AES, "password", "saltiest", 1000, 256));
  EXPECT_TRUE(key.get());

  crypto::Encryptor encryptor;
  // The IV must be exactly as long as the cipher block size.
  std::string iv("the iv: 16 bytes");
  EXPECT_EQ(16U, iv.size());
  EXPECT_TRUE(encryptor.Init(key.get(), crypto::Encryptor::CBC, iv));

  std::string plaintext("this is the plaintext");
  std::string ciphertext;
  EXPECT_TRUE(encryptor.Encrypt(plaintext, &ciphertext));

  EXPECT_LT(0U, ciphertext.size());

  std::string decrypted;
  EXPECT_TRUE(encryptor.Decrypt(ciphertext, &decrypted));

  EXPECT_EQ(plaintext, decrypted);
}

TEST(EncryptorTest, DecryptWrongKey) {
  scoped_ptr<crypto::SymmetricKey> key(
      crypto::SymmetricKey::DeriveKeyFromPassword(
          crypto::SymmetricKey::AES, "password", "saltiest", 1000, 256));
  EXPECT_TRUE(key.get());

  // A wrong key that can be detected by implementations that validate every
  // byte in the padding.
  scoped_ptr<crypto::SymmetricKey> wrong_key(
        crypto::SymmetricKey::DeriveKeyFromPassword(
            crypto::SymmetricKey::AES, "wrongword", "sweetest", 1000, 256));
  EXPECT_TRUE(wrong_key.get());

  // A wrong key that can't be detected by any implementation.  The password
  // "wrongword;" would also work.
  scoped_ptr<crypto::SymmetricKey> wrong_key2(
        crypto::SymmetricKey::DeriveKeyFromPassword(
            crypto::SymmetricKey::AES, "wrongword+", "sweetest", 1000, 256));
  EXPECT_TRUE(wrong_key2.get());

  // A wrong key that can be detected by all implementations.
  scoped_ptr<crypto::SymmetricKey> wrong_key3(
        crypto::SymmetricKey::DeriveKeyFromPassword(
            crypto::SymmetricKey::AES, "wrongwordx", "sweetest", 1000, 256));
  EXPECT_TRUE(wrong_key3.get());

  crypto::Encryptor encryptor;
  // The IV must be exactly as long as the cipher block size.
  std::string iv("the iv: 16 bytes");
  EXPECT_EQ(16U, iv.size());
  EXPECT_TRUE(encryptor.Init(key.get(), crypto::Encryptor::CBC, iv));

  std::string plaintext("this is the plaintext");
  std::string ciphertext;
  EXPECT_TRUE(encryptor.Encrypt(plaintext, &ciphertext));

  static const unsigned char expected_ciphertext[] = {
    0x7D, 0x67, 0x5B, 0x53, 0xE6, 0xD8, 0x0F, 0x27,
    0x74, 0xB1, 0x90, 0xFE, 0x6E, 0x58, 0x4A, 0xA0,
    0x0E, 0x35, 0xE3, 0x01, 0xC0, 0xFE, 0x9A, 0xD8,
    0x48, 0x1D, 0x42, 0xB0, 0xBA, 0x21, 0xB2, 0x0C
  };

  ASSERT_EQ(arraysize(expected_ciphertext), ciphertext.size());
  for (size_t i = 0; i < ciphertext.size(); ++i) {
    ASSERT_EQ(expected_ciphertext[i],
              static_cast<unsigned char>(ciphertext[i]));
  }

  std::string decrypted;

  // This wrong key causes the last padding byte to be 5, which is a valid
  // padding length, and the second to last padding byte to be 137, which is
  // invalid.  If an implementation simply uses the last padding byte to
  // determine the padding length without checking every padding byte,
  // Encryptor::Decrypt() will still return true.  This is the case for NSS
  // (crbug.com/124434).
#if !defined(USE_NSS) && !defined(OS_WIN) && !defined(OS_MACOSX)
  crypto::Encryptor decryptor;
  EXPECT_TRUE(decryptor.Init(wrong_key.get(), crypto::Encryptor::CBC, iv));
  EXPECT_FALSE(decryptor.Decrypt(ciphertext, &decrypted));
#endif

  // This demonstrates that not all wrong keys can be detected by padding
  // error. This wrong key causes the last padding byte to be 1, which is
  // a valid padding block of length 1.
  crypto::Encryptor decryptor2;
  EXPECT_TRUE(decryptor2.Init(wrong_key2.get(), crypto::Encryptor::CBC, iv));
  EXPECT_TRUE(decryptor2.Decrypt(ciphertext, &decrypted));

  // This wrong key causes the last padding byte to be 253, which should be
  // rejected by all implementations.
  crypto::Encryptor decryptor3;
  EXPECT_TRUE(decryptor3.Init(wrong_key3.get(), crypto::Encryptor::CBC, iv));
  EXPECT_FALSE(decryptor3.Decrypt(ciphertext, &decrypted));
}

namespace {

// From NIST SP 800-38a test cast:
// - F.5.1 CTR-AES128.Encrypt
// - F.5.6 CTR-AES256.Encrypt
// http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf
const unsigned char kAES128CTRKey[] = {
  0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6,
  0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c
};

const unsigned char kAES256CTRKey[] = {
  0x60, 0x3d, 0xeb, 0x10, 0x15, 0xca, 0x71, 0xbe,
  0x2b, 0x73, 0xae, 0xf0, 0x85, 0x7d, 0x77, 0x81,
  0x1f, 0x35, 0x2c, 0x07, 0x3b, 0x61, 0x08, 0xd7,
  0x2d, 0x98, 0x10, 0xa3, 0x09, 0x14, 0xdf, 0xf4
};

const unsigned char kAESCTRInitCounter[] = {
  0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
  0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff
};

const unsigned char kAESCTRPlaintext[] = {
  // 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
};

const unsigned char kAES128CTRCiphertext[] = {
  // Block #1
  0x87, 0x4d, 0x61, 0x91, 0xb6, 0x20, 0xe3, 0x26,
  0x1b, 0xef, 0x68, 0x64, 0x99, 0x0d, 0xb6, 0xce,
  // Block #2
  0x98, 0x06, 0xf6, 0x6b, 0x79, 0x70, 0xfd, 0xff,
  0x86, 0x17, 0x18, 0x7b, 0xb9, 0xff, 0xfd, 0xff,
  // Block #3
  0x5a, 0xe4, 0xdf, 0x3e, 0xdb, 0xd5, 0xd3, 0x5e,
  0x5b, 0x4f, 0x09, 0x02, 0x0d, 0xb0, 0x3e, 0xab,
  // Block #4
  0x1e, 0x03, 0x1d, 0xda, 0x2f, 0xbe, 0x03, 0xd1,
  0x79, 0x21, 0x70, 0xa0, 0xf3, 0x00, 0x9c, 0xee
};

const unsigned char kAES256CTRCiphertext[] = {
  // Block #1
  0x60, 0x1e, 0xc3, 0x13, 0x77, 0x57, 0x89, 0xa5,
  0xb7, 0xa7, 0xf5, 0x04, 0xbb, 0xf3, 0xd2, 0x28,
  // Block #2
  0xf4, 0x43, 0xe3, 0xca, 0x4d, 0x62, 0xb5, 0x9a,
  0xca, 0x84, 0xe9, 0x90, 0xca, 0xca, 0xf5, 0xc5,
  // Block #3
  0x2b, 0x09, 0x30, 0xda, 0xa2, 0x3d, 0xe9, 0x4c,
  0xe8, 0x70, 0x17, 0xba, 0x2d, 0x84, 0x98, 0x8d,
  // Block #4
  0xdf, 0xc9, 0xc5, 0x8d, 0xb6, 0x7a, 0xad, 0xa6,
  0x13, 0xc2, 0xdd, 0x08, 0x45, 0x79, 0x41, 0xa6
};

void TestAESCTREncrypt(
    const unsigned char* key, size_t key_size,
    const unsigned char* init_counter, size_t init_counter_size,
    const unsigned char* plaintext, size_t plaintext_size,
    const unsigned char* ciphertext, size_t ciphertext_size) {
  std::string key_str(reinterpret_cast<const char*>(key), key_size);
  scoped_ptr<crypto::SymmetricKey> sym_key(crypto::SymmetricKey::Import(
      crypto::SymmetricKey::AES, key_str));
  ASSERT_TRUE(sym_key.get());

  crypto::Encryptor encryptor;
  EXPECT_TRUE(encryptor.Init(sym_key.get(), crypto::Encryptor::CTR, ""));

  base::StringPiece init_counter_str(
      reinterpret_cast<const char*>(init_counter), init_counter_size);
  base::StringPiece plaintext_str(
      reinterpret_cast<const char*>(plaintext), plaintext_size);

  EXPECT_TRUE(encryptor.SetCounter(init_counter_str));
  std::string encrypted;
  EXPECT_TRUE(encryptor.Encrypt(plaintext_str, &encrypted));

  EXPECT_EQ(ciphertext_size, encrypted.size());
  EXPECT_EQ(0, memcmp(encrypted.data(), ciphertext, encrypted.size()));

  std::string decrypted;
  EXPECT_TRUE(encryptor.SetCounter(init_counter_str));
  EXPECT_TRUE(encryptor.Decrypt(encrypted, &decrypted));

  EXPECT_EQ(plaintext_str, decrypted);
}

void TestAESCTRMultipleDecrypt(
    const unsigned char* key, size_t key_size,
    const unsigned char* init_counter, size_t init_counter_size,
    const unsigned char* plaintext, size_t plaintext_size,
    const unsigned char* ciphertext, size_t ciphertext_size) {
  std::string key_str(reinterpret_cast<const char*>(key), key_size);
  scoped_ptr<crypto::SymmetricKey> sym_key(crypto::SymmetricKey::Import(
      crypto::SymmetricKey::AES, key_str));
  ASSERT_TRUE(sym_key.get());

  crypto::Encryptor encryptor;
  EXPECT_TRUE(encryptor.Init(sym_key.get(), crypto::Encryptor::CTR, ""));

  // Counter is set only once.
  EXPECT_TRUE(encryptor.SetCounter(base::StringPiece(
      reinterpret_cast<const char*>(init_counter), init_counter_size)));

  std::string ciphertext_str(reinterpret_cast<const char*>(ciphertext),
                             ciphertext_size);

  int kTestDecryptSizes[] = { 32, 16, 8 };

  int offset = 0;
  for (size_t i = 0; i < arraysize(kTestDecryptSizes); ++i) {
    std::string decrypted;
    size_t len = kTestDecryptSizes[i];
    EXPECT_TRUE(
        encryptor.Decrypt(ciphertext_str.substr(offset, len), &decrypted));
    EXPECT_EQ(len, decrypted.size());
    EXPECT_EQ(0, memcmp(decrypted.data(), plaintext + offset, len));
    offset += len;
  }
}

}  // namespace

TEST(EncryptorTest, EncryptAES128CTR) {
  TestAESCTREncrypt(
      kAES128CTRKey, arraysize(kAES128CTRKey),
      kAESCTRInitCounter, arraysize(kAESCTRInitCounter),
      kAESCTRPlaintext, arraysize(kAESCTRPlaintext),
      kAES128CTRCiphertext, arraysize(kAES128CTRCiphertext));
}

TEST(EncryptorTest, EncryptAES256CTR) {
  TestAESCTREncrypt(
      kAES256CTRKey, arraysize(kAES256CTRKey),
      kAESCTRInitCounter, arraysize(kAESCTRInitCounter),
      kAESCTRPlaintext, arraysize(kAESCTRPlaintext),
      kAES256CTRCiphertext, arraysize(kAES256CTRCiphertext));
}

TEST(EncryptorTest, EncryptAES128CTR_MultipleDecrypt) {
  TestAESCTRMultipleDecrypt(
      kAES128CTRKey, arraysize(kAES128CTRKey),
      kAESCTRInitCounter, arraysize(kAESCTRInitCounter),
      kAESCTRPlaintext, arraysize(kAESCTRPlaintext),
      kAES128CTRCiphertext, arraysize(kAES128CTRCiphertext));
}

TEST(EncryptorTest, EncryptAES256CTR_MultipleDecrypt) {
  TestAESCTRMultipleDecrypt(
      kAES256CTRKey, arraysize(kAES256CTRKey),
      kAESCTRInitCounter, arraysize(kAESCTRInitCounter),
      kAESCTRPlaintext, arraysize(kAESCTRPlaintext),
      kAES256CTRCiphertext, arraysize(kAES256CTRCiphertext));
}

TEST(EncryptorTest, EncryptDecryptCTR) {
  scoped_ptr<crypto::SymmetricKey> key(
      crypto::SymmetricKey::GenerateRandomKey(crypto::SymmetricKey::AES, 128));

  EXPECT_TRUE(key.get());
  const std::string kInitialCounter = "0000000000000000";

  crypto::Encryptor encryptor;
  EXPECT_TRUE(encryptor.Init(key.get(), crypto::Encryptor::CTR, ""));
  EXPECT_TRUE(encryptor.SetCounter(kInitialCounter));

  std::string plaintext("normal plaintext of random length");
  std::string ciphertext;
  EXPECT_TRUE(encryptor.Encrypt(plaintext, &ciphertext));
  EXPECT_LT(0U, ciphertext.size());

  std::string decrypted;
  EXPECT_TRUE(encryptor.SetCounter(kInitialCounter));
  EXPECT_TRUE(encryptor.Decrypt(ciphertext, &decrypted));
  EXPECT_EQ(plaintext, decrypted);

  plaintext = "0123456789012345";
  EXPECT_TRUE(encryptor.SetCounter(kInitialCounter));
  EXPECT_TRUE(encryptor.Encrypt(plaintext, &ciphertext));
  EXPECT_LT(0U, ciphertext.size());

  EXPECT_TRUE(encryptor.SetCounter(kInitialCounter));
  EXPECT_TRUE(encryptor.Decrypt(ciphertext, &decrypted));
  EXPECT_EQ(plaintext, decrypted);
}

TEST(EncryptorTest, CTRCounter) {
  const int kCounterSize = 16;
  const unsigned char kTest1[] =
      {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
  unsigned char buf[16];

  // Increment 10 times.
  crypto::Encryptor::Counter counter1(
      std::string(reinterpret_cast<const char*>(kTest1), kCounterSize));
  for (int i = 0; i < 10; ++i)
    counter1.Increment();
  counter1.Write(buf);
  EXPECT_EQ(0, memcmp(buf, kTest1, 15));
  EXPECT_TRUE(buf[15] == 10);

  // Check corner cases.
  const unsigned char kTest2[] = {
      0, 0, 0, 0, 0, 0, 0, 0,
      0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
  };
  const unsigned char kExpect2[] =
      {0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0};
  crypto::Encryptor::Counter counter2(
      std::string(reinterpret_cast<const char*>(kTest2), kCounterSize));
  counter2.Increment();
  counter2.Write(buf);
  EXPECT_EQ(0, memcmp(buf, kExpect2, kCounterSize));

  const unsigned char kTest3[] = {
      0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
      0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
  };
  const unsigned char kExpect3[] =
      {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
  crypto::Encryptor::Counter counter3(
      std::string(reinterpret_cast<const char*>(kTest3), kCounterSize));
  counter3.Increment();
  counter3.Write(buf);
  EXPECT_EQ(0, memcmp(buf, kExpect3, kCounterSize));
}

// TODO(wtc): add more known-answer tests.  Test vectors are available from
// http://www.ietf.org/rfc/rfc3602
// http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf
// http://gladman.plushost.co.uk/oldsite/AES/index.php
// http://csrc.nist.gov/groups/STM/cavp/documents/aes/KAT_AES.zip

// NIST SP 800-38A test vector F.2.5 CBC-AES256.Encrypt.
TEST(EncryptorTest, EncryptAES256CBC) {
  // From NIST SP 800-38a test cast F.2.5 CBC-AES256.Encrypt.
  static const unsigned char kRawKey[] = {
    0x60, 0x3d, 0xeb, 0x10, 0x15, 0xca, 0x71, 0xbe,
    0x2b, 0x73, 0xae, 0xf0, 0x85, 0x7d, 0x77, 0x81,
    0x1f, 0x35, 0x2c, 0x07, 0x3b, 0x61, 0x08, 0xd7,
    0x2d, 0x98, 0x10, 0xa3, 0x09, 0x14, 0xdf, 0xf4
  };
  static const unsigned char kRawIv[] = {
    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f
  };
  static const unsigned char kRawPlaintext[] = {
    // 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 unsigned char kRawCiphertext[] = {
    // Block #1
    0xf5, 0x8c, 0x4c, 0x04, 0xd6, 0xe5, 0xf1, 0xba,
    0x77, 0x9e, 0xab, 0xfb, 0x5f, 0x7b, 0xfb, 0xd6,
    // Block #2
    0x9c, 0xfc, 0x4e, 0x96, 0x7e, 0xdb, 0x80, 0x8d,
    0x67, 0x9f, 0x77, 0x7b, 0xc6, 0x70, 0x2c, 0x7d,
    // Block #3
    0x39, 0xf2, 0x33, 0x69, 0xa9, 0xd9, 0xba, 0xcf,
    0xa5, 0x30, 0xe2, 0x63, 0x04, 0x23, 0x14, 0x61,
    // Block #4
    0xb2, 0xeb, 0x05, 0xe2, 0xc3, 0x9b, 0xe9, 0xfc,
    0xda, 0x6c, 0x19, 0x07, 0x8c, 0x6a, 0x9d, 0x1b,
    // PKCS #5 padding, encrypted.
    0x3f, 0x46, 0x17, 0x96, 0xd6, 0xb0, 0xd6, 0xb2,
    0xe0, 0xc2, 0xa7, 0x2b, 0x4d, 0x80, 0xe6, 0x44
  };

  std::string key(reinterpret_cast<const char*>(kRawKey), sizeof(kRawKey));
  scoped_ptr<crypto::SymmetricKey> sym_key(crypto::SymmetricKey::Import(
      crypto::SymmetricKey::AES, key));
  ASSERT_TRUE(sym_key.get());

  crypto::Encryptor encryptor;
  // The IV must be exactly as long a the cipher block size.
  std::string iv(reinterpret_cast<const char*>(kRawIv), sizeof(kRawIv));
  EXPECT_EQ(16U, iv.size());
  EXPECT_TRUE(encryptor.Init(sym_key.get(), crypto::Encryptor::CBC, iv));

  std::string plaintext(reinterpret_cast<const char*>(kRawPlaintext),
                        sizeof(kRawPlaintext));
  std::string ciphertext;
  EXPECT_TRUE(encryptor.Encrypt(plaintext, &ciphertext));

  EXPECT_EQ(sizeof(kRawCiphertext), ciphertext.size());
  EXPECT_EQ(0, memcmp(ciphertext.data(), kRawCiphertext, ciphertext.size()));

  std::string decrypted;
  EXPECT_TRUE(encryptor.Decrypt(ciphertext, &decrypted));

  EXPECT_EQ(plaintext, decrypted);
}

// Expected output derived from the NSS implementation.
TEST(EncryptorTest, EncryptAES128CBCRegression) {
  std::string key = "128=SixteenBytes";
  std::string iv = "Sweet Sixteen IV";
  std::string plaintext = "Plain text with a g-clef U+1D11E \360\235\204\236";
  std::string expected_ciphertext_hex =
      "D4A67A0BA33C30F207344D81D1E944BBE65587C3D7D9939A"
      "C070C62B9C15A3EA312EA4AD1BC7929F4D3C16B03AD5ADA8";

  scoped_ptr<crypto::SymmetricKey> sym_key(crypto::SymmetricKey::Import(
      crypto::SymmetricKey::AES, key));
  ASSERT_TRUE(sym_key.get());

  crypto::Encryptor encryptor;
  // The IV must be exactly as long a the cipher block size.
  EXPECT_EQ(16U, iv.size());
  EXPECT_TRUE(encryptor.Init(sym_key.get(), crypto::Encryptor::CBC, iv));

  std::string ciphertext;
  EXPECT_TRUE(encryptor.Encrypt(plaintext, &ciphertext));
  EXPECT_EQ(expected_ciphertext_hex, base::HexEncode(ciphertext.data(),
                                                     ciphertext.size()));

  std::string decrypted;
  EXPECT_TRUE(encryptor.Decrypt(ciphertext, &decrypted));
  EXPECT_EQ(plaintext, decrypted);
}

// Expected output derived from the NSS implementation.
TEST(EncryptorTest, EncryptAES192CBCRegression) {
  std::string key = "192bitsIsTwentyFourByte!";
  std::string iv = "Sweet Sixteen IV";
  std::string plaintext = "Small text";
  std::string expected_ciphertext_hex = "78DE5D7C2714FC5C61346C5416F6C89A";

  scoped_ptr<crypto::SymmetricKey> sym_key(crypto::SymmetricKey::Import(
      crypto::SymmetricKey::AES, key));
  ASSERT_TRUE(sym_key.get());

  crypto::Encryptor encryptor;
  // The IV must be exactly as long a the cipher block size.
  EXPECT_EQ(16U, iv.size());
  EXPECT_TRUE(encryptor.Init(sym_key.get(), crypto::Encryptor::CBC, iv));

  std::string ciphertext;
  EXPECT_TRUE(encryptor.Encrypt(plaintext, &ciphertext));
  EXPECT_EQ(expected_ciphertext_hex, base::HexEncode(ciphertext.data(),
                                                     ciphertext.size()));

  std::string decrypted;
  EXPECT_TRUE(encryptor.Decrypt(ciphertext, &decrypted));
  EXPECT_EQ(plaintext, decrypted);
}

// Not all platforms allow import/generation of symmetric keys with an
// unsupported size.
#if !defined(USE_NSS) && !defined(OS_WIN) && !defined(OS_MACOSX)
TEST(EncryptorTest, UnsupportedKeySize) {
  std::string key = "7 = bad";
  std::string iv = "Sweet Sixteen IV";
  scoped_ptr<crypto::SymmetricKey> sym_key(crypto::SymmetricKey::Import(
      crypto::SymmetricKey::AES, key));
  ASSERT_TRUE(sym_key.get());

  crypto::Encryptor encryptor;
  // The IV must be exactly as long a the cipher block size.
  EXPECT_EQ(16U, iv.size());
  EXPECT_FALSE(encryptor.Init(sym_key.get(), crypto::Encryptor::CBC, iv));
}
#endif  // unsupported platforms.

TEST(EncryptorTest, UnsupportedIV) {
  std::string key = "128=SixteenBytes";
  std::string iv = "OnlyForteen :(";
  scoped_ptr<crypto::SymmetricKey> sym_key(crypto::SymmetricKey::Import(
      crypto::SymmetricKey::AES, key));
  ASSERT_TRUE(sym_key.get());

  crypto::Encryptor encryptor;
  EXPECT_FALSE(encryptor.Init(sym_key.get(), crypto::Encryptor::CBC, iv));
}

TEST(EncryptorTest, EmptyEncrypt) {
  std::string key = "128=SixteenBytes";
  std::string iv = "Sweet Sixteen IV";
  std::string plaintext;
  std::string expected_ciphertext_hex = "8518B8878D34E7185E300D0FCC426396";

  scoped_ptr<crypto::SymmetricKey> sym_key(crypto::SymmetricKey::Import(
      crypto::SymmetricKey::AES, key));
  ASSERT_TRUE(sym_key.get());

  crypto::Encryptor encryptor;
  // The IV must be exactly as long a the cipher block size.
  EXPECT_EQ(16U, iv.size());
  EXPECT_TRUE(encryptor.Init(sym_key.get(), crypto::Encryptor::CBC, iv));

  std::string ciphertext;
  EXPECT_TRUE(encryptor.Encrypt(plaintext, &ciphertext));
  EXPECT_EQ(expected_ciphertext_hex, base::HexEncode(ciphertext.data(),
                                                     ciphertext.size()));
}

TEST(EncryptorTest, CipherTextNotMultipleOfBlockSize) {
  std::string key = "128=SixteenBytes";
  std::string iv = "Sweet Sixteen IV";

  scoped_ptr<crypto::SymmetricKey> sym_key(crypto::SymmetricKey::Import(
      crypto::SymmetricKey::AES, key));
  ASSERT_TRUE(sym_key.get());

  crypto::Encryptor encryptor;
  // The IV must be exactly as long a the cipher block size.
  EXPECT_EQ(16U, iv.size());
  EXPECT_TRUE(encryptor.Init(sym_key.get(), crypto::Encryptor::CBC, iv));

  // Use a separately allocated array to improve the odds of the memory tools
  // catching invalid accesses.
  //
  // Otherwise when using std::string as the other tests do, accesses several
  // bytes off the end of the buffer may fall inside the reservation of
  // the string and not be detected.
  scoped_ptr<char[]> ciphertext(new char[1]);

  std::string plaintext;
  EXPECT_FALSE(
      encryptor.Decrypt(base::StringPiece(ciphertext.get(), 1), &plaintext));
}