Implement AES-CTR for NSS.

crypto/encryptor_unittest.cc

 // 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 "crypto/encryptor.h"
 
 #include <string>
 
+#include "base/rand_util.h"

[Ryan Sleevi, 2011/06/15 06:27:00]

not needed; see below.

 #include "base/memory/scoped_ptr.h"
 #include "base/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(NULL != 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 decypted;
   EXPECT_TRUE(encryptor.Decrypt(ciphertext, &decypted));
 
   EXPECT_EQ(plaintext, decypted);
 }
 
+// ECB mode encryption is only implemented using NSS.
+#if defined(USE_NSS)
+
+TEST(EncryptorTest, EncryptDecryptCTR) {
+  scoped_ptr<crypto::SymmetricKey> key(
+      crypto::SymmetricKey::Import(crypto::SymmetricKey::AES,
+                                   base::RandBytesAsString(16)));

[Ryan Sleevi, 2011/06/15 06:27:00]

nit: crypto::SymmetricKey::GenerateRandomKey(crypto::SymmetricKey::AES, 128)

[Alpha Left Google, 2011/06/15 18:54:42]

Done.

+
+  EXPECT_TRUE(NULL != key.get());
+  const std::string kInitialCounter = "0000000000000000";
+
+  crypto::Encryptor encryptor;
+  EXPECT_TRUE(encryptor.Init(key.get(), crypto::Encryptor::CTR, ""));
+  EXPECT_TRUE(encryptor.UpdateCounter(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 decypted;
+  EXPECT_TRUE(encryptor.UpdateCounter(kInitialCounter));
+  EXPECT_TRUE(encryptor.Decrypt(ciphertext, &decypted));
+
+  EXPECT_EQ(plaintext, decypted);
+}
+
+TEST(EncryptorTest, CTRCounter) {
+  const int kCounterSize = 16;
+  const char kTest1[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+  uint8 buf[16];
+
+  // Increment 10 times.
+  crypto::Encryptor::Counter counter1(std::string(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 char kTest2[] = {0, 0, 0, 0, 0, 0, 0, 0,
+                         0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
+  const char kExpect2[] = {0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0};
+  crypto::Encryptor::Counter counter2(std::string(kTest2, kCounterSize));
+  counter2.Increment();
+  counter2.Write(buf);
+  EXPECT_EQ(0, memcmp(buf, kExpect2, kCounterSize));
+
+  const char kTest3[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+                         0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
+  const char kExpect3[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+  crypto::Encryptor::Counter counter3(std::string(kTest3, kCounterSize));
+  counter3.Increment();
+  counter3.Write(buf);
+  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
 // 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 raw_key[] = {
@@ skipping 176 matching lines @@
 
   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 decrypted;
   EXPECT_FALSE(encryptor.Decrypt("", &decrypted));
   EXPECT_EQ("", decrypted);
 }