1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4//
5// A helper library to keep track of a user's key by SID.
6// Used by RLZ libary. Also to be used by SearchWithGoogle library.
7
8#include "rlz/win/lib/registry_util.h"
9
10#include "base/process/process_handle.h"
11#include "base/strings/utf_string_conversions.h"
12#include "base/win/registry.h"
13#include "base/win/windows_version.h"
14#include "rlz/lib/assert.h"
15#include "rlz/win/lib/process_info.h"
16
17namespace rlz_lib {
18
19bool RegKeyReadValue(base::win::RegKey& key, const wchar_t* name,
20                     char* value, size_t* value_size) {
21  value[0] = 0;
22
23  std::wstring value_string;
24  if (key.ReadValue(name, &value_string) != ERROR_SUCCESS) {
25    return false;
26  }
27
28  if (value_string.length() > *value_size) {
29    *value_size = value_string.length();
30    return false;
31  }
32
33  // Note that RLZ string are always ASCII by design.
34  strncpy(value, base::WideToUTF8(value_string).c_str(), *value_size);
35  value[*value_size - 1] = 0;
36  return true;
37}
38
39bool RegKeyWriteValue(base::win::RegKey& key, const wchar_t* name,
40                      const char* value) {
41  std::wstring value_string(base::ASCIIToWide(value));
42  return key.WriteValue(name, value_string.c_str()) == ERROR_SUCCESS;
43}
44
45bool HasUserKeyAccess(bool write_access) {
46  // The caller is trying to access HKEY_CURRENT_USER.  Test to see if we can
47  // read from there.  Don't try HKEY_CURRENT_USER because this will cause
48  // problems in the unit tests: if we open HKEY_CURRENT_USER directly here,
49  // the overriding done for unit tests will no longer work.  So we try subkey
50  // "Software" which is known to always exist.
51  base::win::RegKey key;
52  if (key.Open(HKEY_CURRENT_USER, L"Software", KEY_READ) != ERROR_SUCCESS)
53    ASSERT_STRING("Could not open HKEY_CURRENT_USER");
54
55  if (ProcessInfo::IsRunningAsSystem()) {
56    ASSERT_STRING("UserKey::HasAccess: No access as SYSTEM without SID set.");
57    return false;
58  }
59
60  if (write_access) {
61    if (base::win::GetVersion() < base::win::VERSION_VISTA) return true;
62    base::ProcessHandle process_handle = base::GetCurrentProcessHandle();
63    base::IntegrityLevel level = base::INTEGRITY_UNKNOWN;
64
65    if (!base::GetProcessIntegrityLevel(process_handle, &level)) {
66      ASSERT_STRING("UserKey::HasAccess: Cannot determine Integrity Level.");
67      return false;
68    }
69    if (level <= base::LOW_INTEGRITY) {
70      ASSERT_STRING("UserKey::HasAccess: Cannot write from Low Integrity.");
71      return false;
72    }
73  }
74  return true;
75}
76
77}  // namespace rlz_lib
78