Initial commit of sync engine code to browser/sync....

chrome/browser/sync/util/data_encryption.cc

+// Copyright (c) 2009 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.
+//
+// NOTE: this file is Winodws specific.
+
+#include "chrome/browser/sync/util/data_encryption.h"
+
+#include <windows.h>
+#include <wincrypt.h>
+
+#include <cstddef>
+#include <string>
+#include <vector>
+
+using std::string;
+using std::vector;
+
+vector<uint8> EncryptData(const string& data) {
+  DATA_BLOB unencrypted_data, encrypted_data;
+  unencrypted_data.pbData = (BYTE*)(data.data());
+  unencrypted_data.cbData = data.size();
+
+  if (!CryptProtectData(&unencrypted_data, L"", NULL, NULL, NULL, 0,
+                        &encrypted_data))
+    LOG(ERROR) << "Encryption fails: " << data;
+
+  vector<uint8> result(encrypted_data.pbData,
+                       encrypted_data.pbData + encrypted_data.cbData);
+  LocalFree(encrypted_data.pbData);
+  return result;
+}
+
+bool DecryptData(const vector<uint8>& in_data, string* out_data) {
+  DATA_BLOB encrypted_data, decrypted_data;
+  encrypted_data.pbData =
+    (in_data.empty() ? NULL : const_cast<BYTE*>(&in_data[0]));
+  encrypted_data.cbData = in_data.size();
+  LPWSTR descrip = L"";
+
+  if (!CryptUnprotectData(&encrypted_data, &descrip, NULL, NULL, NULL, 0,
+                          &decrypted_data)) {
+    LOG(ERROR) << "Decryption fails: ";
+    return false;
+  } else {
+    out_data->assign(reinterpret_cast<const char*>(decrypted_data.pbData),
+                     decrypted_data.cbData);
+    LocalFree(decrypted_data.pbData);
+    return true;
+  }
+}