1 files changed, 114 insertions, 8 deletions

diff --git a/chrome/browser/password_manager/encryptor_mac.mm b/chrome/browser/password_manager/encryptor_mac.mm
index 44ed207..0e7ce2f 100644
--- a/chrome/browser/password_manager/encryptor_mac.mm
+++ b/chrome/browser/password_manager/encryptor_mac.mm
@@ -1,11 +1,71 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 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 "chrome/browser/password_manager/encryptor.h"
 
+#include <CommonCrypto/CommonCryptor.h>  // for kCCBlockSizeAES128
+
+#include "base/crypto/encryptor.h"
+#include "base/crypto/symmetric_key.h"
 #include "base/logging.h"
+#include "base/scoped_ptr.h"
 #include "base/utf_string_conversions.h"
+#include "chrome/browser/password_manager/encryptor_password_mac.h"
+#include "chrome/browser/keychain_mac.h"
+
+namespace {
+
+// Salt for Symmetric key derivation.
+const char kSalt[] = "saltysalt";
+
+// Key size required for 128 bit AES.
+const size_t kDerivedKeySizeInBits = 128;
+
+// Constant for Symmetic key derivation.
+const size_t kEncryptionIterations = 1003;
+
+// TODO(dhollowa): Refactor to allow dependency injection of Keychain.
+static bool use_mock_keychain = false;
+
+// Prefix for cypher text returned by current encryption version.  We prefix
+// the cypher text with this string so that future data migration can detect
+// this and migrate to different encryption without data loss.
+const char kEncryptionVersionPrefix[] = "v10";
+
+// Generates a newly allocated SymmetricKey object based on the password found
+// in the Keychain.  The generated key is for AES encryption.  Ownership of the
+// key is passed to the caller.  Returns NULL key in the case password access
+// is denied or key generation error occurs.
+base::SymmetricKey* GetEncryptionKey() {
+
+  std::string password;
+  if (use_mock_keychain) {
+    password = "mock_password";
+  } else {
+    MacKeychain keychain;
+    EncryptorPassword encryptor_password(keychain);
+    password = encryptor_password.GetEncryptorPassword();
+  }
+
+  if (password.empty())
+    return NULL;
+
+  std::string salt(kSalt);
+
+  // Create an encryption key from our password and salt.
+  scoped_ptr<base::SymmetricKey> encryption_key(
+      base::SymmetricKey::DeriveKeyFromPassword(base::SymmetricKey::AES,
+                                                password,
+                                                salt,
+                                                kEncryptionIterations,
+                                                kDerivedKeySizeInBits));
+  DCHECK(encryption_key.get());
+
+  return encryption_key.release();
+}
+
+}  // namespace
 
 bool Encryptor::EncryptString16(const string16& plaintext,
                                 std::string* ciphertext) {
@@ -24,19 +84,65 @@ bool Encryptor::DecryptString16(const std::string& ciphertext,
 
 bool Encryptor::EncryptString(const std::string& plaintext,
                               std::string* ciphertext) {
-  // This doesn't actually encrypt, we need to work on the Encryptor API.
-  // http://code.google.com/p/chromium/issues/detail?id=25404
+  if (plaintext.empty()) {
+    *ciphertext = std::string();
+    return true;
+  }
+
+  scoped_ptr<base::SymmetricKey> encryption_key(GetEncryptionKey());
+  if (!encryption_key.get())
+    return false;
+
+  std::string iv(kCCBlockSizeAES128, ' ');
+  base::Encryptor encryptor;
+  if (!encryptor.Init(encryption_key.get(), base::Encryptor::CBC, iv))
+    return false;
+
+  if (!encryptor.Encrypt(plaintext, ciphertext))
+    return false;
 
-  // this does a copy
-  ciphertext->assign(plaintext.data(), plaintext.length());
+  // Prefix the cypher text with version information.
+  ciphertext->insert(0, kEncryptionVersionPrefix);
   return true;
 }
 
 bool Encryptor::DecryptString(const std::string& ciphertext,
                               std::string* plaintext) {
-  // This doesn't actually decrypt, we need to work on the Encryptor API.
-  // http://code.google.com/p/chromium/issues/detail?id=25404
+  if (ciphertext.empty()) {
+    *plaintext = std::string();
+    return true;
+  }
+
+  // Check that the incoming cyphertext was indeed encrypted with the expected
+  // version.  If the prefix is not found then we'll assume we're dealing with
+  // old data saved as clear text and we'll return it directly.
+  // Credit card numbers are current legacy data, so false match with prefix
+  // won't happen.
+  if (ciphertext.find(kEncryptionVersionPrefix) != 0) {
+    *plaintext = ciphertext;
+    return true;
+  }
+
+  // Strip off the versioning prefix before decrypting.
+  std::string raw_ciphertext =
+      ciphertext.substr(strlen(kEncryptionVersionPrefix));
+
+  scoped_ptr<base::SymmetricKey> encryption_key(GetEncryptionKey());
+  if (!encryption_key.get())
+    return false;
+
+  std::string iv(kCCBlockSizeAES128, ' ');
+  base::Encryptor encryptor;
+  if (!encryptor.Init(encryption_key.get(), base::Encryptor::CBC, iv))
+    return false;
+
+  if (!encryptor.Decrypt(raw_ciphertext, plaintext))
+    return false;
 
-  plaintext->assign(ciphertext.data(), ciphertext.length());
   return true;
 }
+
+void Encryptor::UseMockKeychain(bool use_mock) {
+  use_mock_keychain = use_mock;
+}
+