Support CTR-AES in encryptor_openssl.

BUG=163552
TEST=Added unittest to cover CTR-AES encryption/decryption. Also tested
AesDecryptorTest in media_unittests.

Review URL: https://chromiumcodereview.appspot.com/16654005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@206141 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 240 insertions, 33 deletions

diff --git a/crypto/encryptor.h b/crypto/encryptor.h
index c91d5a4..bcc647b 100644
--- a/crypto/encryptor.h
+++ b/crypto/encryptor.h
@@ -114,9 +114,12 @@ class CRYPTO_EXPORT Encryptor {
   scoped_ptr<Counter> counter_;
 
 #if defined(USE_OPENSSL)
-  bool Crypt(bool encrypt,  // Pass true to encrypt, false to decrypt.
+  bool Crypt(bool do_encrypt,  // Pass true to encrypt, false to decrypt.
              const base::StringPiece& input,
              std::string* output);
+  bool CryptCTR(bool do_encrypt,
+                const base::StringPiece& input,
+                std::string* output);
   std::string iv_;
 #elif defined(USE_NSS) || defined(OS_WIN) || defined(OS_MACOSX)
   bool Crypt(PK11Context* context,
diff --git a/crypto/encryptor_openssl.cc b/crypto/encryptor_openssl.cc
index b643c72..0bf96b7 100644
--- a/crypto/encryptor_openssl.cc
+++ b/crypto/encryptor_openssl.cc
@@ -56,10 +56,10 @@ bool Encryptor::Init(SymmetricKey* key,
                      Mode mode,
                      const base::StringPiece& iv) {
   DCHECK(key);
-  DCHECK_EQ(CBC, mode);
+  DCHECK(mode == CBC || mode == CTR);
 
   EnsureOpenSSLInit();
-  if (iv.size() != AES_BLOCK_SIZE)
+  if (mode == CBC && iv.size() != AES_BLOCK_SIZE)
     return false;
 
   if (GetCipherForKey(key) == NULL)
@@ -74,13 +74,17 @@ bool Encryptor::Init(SymmetricKey* key,
 bool Encryptor::Encrypt(const base::StringPiece& plaintext,
                         std::string* ciphertext) {
   CHECK(!plaintext.empty() || (mode_ == CBC));
-  return Crypt(true, plaintext, ciphertext);
+  return (mode_ == CTR) ?
+      CryptCTR(true, plaintext, ciphertext) :
+      Crypt(true, plaintext, ciphertext);
 }
 
 bool Encryptor::Decrypt(const base::StringPiece& ciphertext,
                         std::string* plaintext) {
   CHECK(!ciphertext.empty());
-  return Crypt(false, ciphertext, plaintext);
+  return (mode_ == CTR) ?
+      CryptCTR(false, ciphertext, plaintext) :
+      Crypt(false, ciphertext, plaintext);
 }
 
 bool Encryptor::Crypt(bool do_encrypt,
@@ -132,4 +136,42 @@ bool Encryptor::Crypt(bool do_encrypt,
   return true;
 }
 
+bool Encryptor::CryptCTR(bool do_encrypt,
+                         const base::StringPiece& input,
+                         std::string* output) {
+  if (!counter_.get()) {
+    LOG(ERROR) << "Counter value not set in CTR mode.";
+    return false;
+  }
+
+  AES_KEY aes_key;
+  if (AES_set_encrypt_key(reinterpret_cast<const uint8*>(key_->key().data()),
+                          key_->key().size() * 8, &aes_key) != 0) {
+    return false;
+  }
+
+  const size_t out_size = input.size();
+  CHECK_GT(out_size, 0u);
+  CHECK_GT(out_size + 1, input.size());
+
+  std::string result;
+  uint8* out_ptr = reinterpret_cast<uint8*>(WriteInto(&result, out_size + 1));
+
+  uint8_t ivec[AES_BLOCK_SIZE] = { 0 };
+  uint8_t ecount_buf[AES_BLOCK_SIZE] = { 0 };
+  unsigned int block_offset = 0;
+
+  counter_->Write(ivec);
+
+  AES_ctr128_encrypt(reinterpret_cast<const uint8*>(input.data()), out_ptr,
+                     input.size(), &aes_key, ivec, ecount_buf, &block_offset);
+
+  // AES_ctr128_encrypt() updates |ivec|. Update the |counter_| here.
+  SetCounter(base::StringPiece(reinterpret_cast<const char*>(ivec),
+                               AES_BLOCK_SIZE));
+
+  output->swap(result);
+  return true;
+}
+
 }  // namespace crypto
diff --git a/crypto/encryptor_unittest.cc b/crypto/encryptor_unittest.cc
index 5b234d2..2f569e1 100644
--- a/crypto/encryptor_unittest.cc
+++ b/crypto/encryptor_unittest.cc
@@ -15,7 +15,7 @@ TEST(EncryptorTest, EncryptDecrypt) {
   scoped_ptr<crypto::SymmetricKey> key(
       crypto::SymmetricKey::DeriveKeyFromPassword(
           crypto::SymmetricKey::AES, "password", "saltiest", 1000, 256));
-  EXPECT_TRUE(NULL != key.get());
+  EXPECT_TRUE(key.get());
 
   crypto::Encryptor encryptor;
   // The IV must be exactly as long as the cipher block size.
@@ -39,27 +39,27 @@ TEST(EncryptorTest, DecryptWrongKey) {
   scoped_ptr<crypto::SymmetricKey> key(
       crypto::SymmetricKey::DeriveKeyFromPassword(
           crypto::SymmetricKey::AES, "password", "saltiest", 1000, 256));
-  EXPECT_TRUE(NULL != key.get());
+  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(NULL != wrong_key.get());
+  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(NULL != wrong_key2.get());
+  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(NULL != wrong_key3.get());
+  EXPECT_TRUE(wrong_key3.get());
 
   crypto::Encryptor encryptor;
   // The IV must be exactly as long as the cipher block size.
@@ -112,15 +112,179 @@ TEST(EncryptorTest, DecryptWrongKey) {
   EXPECT_FALSE(decryptor3.Decrypt(ciphertext, &decypted));
 }
 
-// CTR mode encryption is only implemented using NSS.
-#if defined(USE_NSS) || defined(OS_WIN) || defined(OS_MACOSX)
+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 decypted;
+  EXPECT_TRUE(encryptor.SetCounter(init_counter_str));
+  EXPECT_TRUE(encryptor.Decrypt(encrypted, &decypted));
+
+  EXPECT_EQ(plaintext_str, decypted);
+}
+
+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 decypted;
+    size_t len = kTestDecryptSizes[i];
+    EXPECT_TRUE(
+        encryptor.Decrypt(ciphertext_str.substr(offset, len), &decypted));
+    EXPECT_EQ(len, decypted.size());
+    EXPECT_EQ(0, memcmp(decypted.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));
+      crypto::SymmetricKey::GenerateRandomKey(crypto::SymmetricKey::AES, 128));
 
-  EXPECT_TRUE(NULL != key.get());
+  EXPECT_TRUE(key.get());
   const std::string kInitialCounter = "0000000000000000";
 
   crypto::Encryptor encryptor;
@@ -188,8 +352,6 @@ TEST(EncryptorTest, CTRCounter) {
   EXPECT_EQ(0, memcmp(buf, kExpect3, kCounterSize));
 }
 
-#endif
-
 // 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
@@ -199,17 +361,17 @@ TEST(EncryptorTest, CTRCounter) {
 // 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 raw_key[] = {
+  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 raw_iv[] = {
+  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 raw_plaintext[] = {
+  static const unsigned char kRawPlaintext[] = {
     // Block #1
     0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96,
     0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
@@ -223,7 +385,7 @@ TEST(EncryptorTest, EncryptAES256CBC) {
     0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17,
     0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10,
   };
-  static const unsigned char raw_ciphertext[] = {
+  static const unsigned char kRawCiphertext[] = {
     // Block #1
     0xf5, 0x8c, 0x4c, 0x04, 0xd6, 0xe5, 0xf1, 0xba,
     0x77, 0x9e, 0xab, 0xfb, 0x5f, 0x7b, 0xfb, 0xd6,
@@ -241,24 +403,24 @@ TEST(EncryptorTest, EncryptAES256CBC) {
     0xe0, 0xc2, 0xa7, 0x2b, 0x4d, 0x80, 0xe6, 0x44
   };
 
-  std::string key(reinterpret_cast<const char*>(raw_key), sizeof(raw_key));
+  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(NULL != sym_key.get());
+  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*>(raw_iv), sizeof(raw_iv));
+  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*>(raw_plaintext),
-                        sizeof(raw_plaintext));
+  std::string plaintext(reinterpret_cast<const char*>(kRawPlaintext),
+                        sizeof(kRawPlaintext));
   std::string ciphertext;
   EXPECT_TRUE(encryptor.Encrypt(plaintext, &ciphertext));
 
-  EXPECT_EQ(sizeof(raw_ciphertext), ciphertext.size());
-  EXPECT_EQ(0, memcmp(ciphertext.data(), raw_ciphertext, ciphertext.size()));
+  EXPECT_EQ(sizeof(kRawCiphertext), ciphertext.size());
+  EXPECT_EQ(0, memcmp(ciphertext.data(), kRawCiphertext, ciphertext.size()));
 
   std::string decypted;
   EXPECT_TRUE(encryptor.Decrypt(ciphertext, &decypted));
@@ -277,7 +439,7 @@ TEST(EncryptorTest, EncryptAES128CBCRegression) {
 
   scoped_ptr<crypto::SymmetricKey> sym_key(crypto::SymmetricKey::Import(
       crypto::SymmetricKey::AES, key));
-  ASSERT_TRUE(NULL != sym_key.get());
+  ASSERT_TRUE(sym_key.get());
 
   crypto::Encryptor encryptor;
   // The IV must be exactly as long a the cipher block size.
@@ -303,7 +465,7 @@ TEST(EncryptorTest, EncryptAES192CBCRegression) {
 
   scoped_ptr<crypto::SymmetricKey> sym_key(crypto::SymmetricKey::Import(
       crypto::SymmetricKey::AES, key));
-  ASSERT_TRUE(NULL != sym_key.get());
+  ASSERT_TRUE(sym_key.get());
 
   crypto::Encryptor encryptor;
   // The IV must be exactly as long a the cipher block size.
@@ -328,7 +490,7 @@ TEST(EncryptorTest, UnsupportedKeySize) {
   std::string iv = "Sweet Sixteen IV";
   scoped_ptr<crypto::SymmetricKey> sym_key(crypto::SymmetricKey::Import(
       crypto::SymmetricKey::AES, key));
-  ASSERT_TRUE(NULL != sym_key.get());
+  ASSERT_TRUE(sym_key.get());
 
   crypto::Encryptor encryptor;
   // The IV must be exactly as long a the cipher block size.
@@ -342,7 +504,7 @@ TEST(EncryptorTest, UnsupportedIV) {
   std::string iv = "OnlyForteen :(";
   scoped_ptr<crypto::SymmetricKey> sym_key(crypto::SymmetricKey::Import(
       crypto::SymmetricKey::AES, key));
-  ASSERT_TRUE(NULL != sym_key.get());
+  ASSERT_TRUE(sym_key.get());
 
   crypto::Encryptor encryptor;
   EXPECT_FALSE(encryptor.Init(sym_key.get(), crypto::Encryptor::CBC, iv));
@@ -356,7 +518,7 @@ TEST(EncryptorTest, EmptyEncrypt) {
 
   scoped_ptr<crypto::SymmetricKey> sym_key(crypto::SymmetricKey::Import(
       crypto::SymmetricKey::AES, key));
-  ASSERT_TRUE(NULL != sym_key.get());
+  ASSERT_TRUE(sym_key.get());
 
   crypto::Encryptor encryptor;
   // The IV must be exactly as long a the cipher block size.