The Tor Browser: security/sandbox/chromium/base/win/registry.cc@141e0f1194b1 (annotated)

security/sandbox/chromium/base/win/registry.cc@141e0f1194b1 (annotated)

security/sandbox/chromium/base/win/registry.cc

Wed, 31 Dec 2014 07:16:47 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 07:16:47 +0100
branch: TOR_BUG_9701
changeset 3: 141e0f1194b1
permissions: -rw-r--r--

Revert simplistic fix pending revisit of Mozilla integration attempt.

 // Copyright (c) 2012 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 "base/win/registry.h"
 #include <shlwapi.h>
 #include <algorithm>
 #include "base/logging.h"
 #include "base/strings/string_util.h"
 #include "base/threading/thread_restrictions.h"
 #pragma comment(lib, "shlwapi.lib")  // for SHDeleteKey
 namespace base {
 namespace win {
 namespace {
 // RegEnumValue() reports the number of characters from the name that were
 // written to the buffer, not how many there are. This constant is the maximum
 // name size, such that a buffer with this size should read any name.
 const DWORD MAX_REGISTRY_NAME_SIZE = 16384;
 // Registry values are read as BYTE* but can have wchar_t* data whose last
 // wchar_t is truncated. This function converts the reported |byte_size| to
 // a size in wchar_t that can store a truncated wchar_t if necessary.
 inline DWORD to_wchar_size(DWORD byte_size) {
   return (byte_size + sizeof(wchar_t) - 1) / sizeof(wchar_t);
 }
 }  // namespace
 // RegKey ----------------------------------------------------------------------
 RegKey::RegKey()
     : key_(NULL),
       watch_event_(0) {
 }
 RegKey::RegKey(HKEY key)
     : key_(key),
       watch_event_(0) {
 }
 RegKey::RegKey(HKEY rootkey, const wchar_t* subkey, REGSAM access)
     : key_(NULL),
       watch_event_(0) {
   if (rootkey) {
     if (access & (KEY_SET_VALUE | KEY_CREATE_SUB_KEY | KEY_CREATE_LINK))
       Create(rootkey, subkey, access);
     else
       Open(rootkey, subkey, access);
   } else {
     DCHECK(!subkey);
   }
 }
 RegKey::~RegKey() {
   Close();
 }
 LONG RegKey::Create(HKEY rootkey, const wchar_t* subkey, REGSAM access) {
   DWORD disposition_value;
   return CreateWithDisposition(rootkey, subkey, &disposition_value, access);
 }
 LONG RegKey::CreateWithDisposition(HKEY rootkey, const wchar_t* subkey,
                                    DWORD* disposition, REGSAM access) {
   DCHECK(rootkey && subkey && access && disposition);
   Close();
   LONG result = RegCreateKeyEx(rootkey, subkey, 0, NULL,
                                REG_OPTION_NON_VOLATILE, access, NULL, &key_,
                                disposition);
   return result;
 }
 LONG RegKey::CreateKey(const wchar_t* name, REGSAM access) {
   DCHECK(name && access);
   HKEY subkey = NULL;
   LONG result = RegCreateKeyEx(key_, name, 0, NULL, REG_OPTION_NON_VOLATILE,
                                access, NULL, &subkey, NULL);
   Close();
   key_ = subkey;
   return result;
 }
 LONG RegKey::Open(HKEY rootkey, const wchar_t* subkey, REGSAM access) {
   DCHECK(rootkey && subkey && access);
   Close();
   LONG result = RegOpenKeyEx(rootkey, subkey, 0, access, &key_);
   return result;
 }
 LONG RegKey::OpenKey(const wchar_t* relative_key_name, REGSAM access) {
   DCHECK(relative_key_name && access);
   HKEY subkey = NULL;
   LONG result = RegOpenKeyEx(key_, relative_key_name, 0, access, &subkey);
   // We have to close the current opened key before replacing it with the new
   // one.
   Close();
   key_ = subkey;
   return result;
 }
 void RegKey::Close() {
   StopWatching();
   if (key_) {
     ::RegCloseKey(key_);
     key_ = NULL;
   }
 }
 void RegKey::Set(HKEY key) {
   if (key_ != key) {
     Close();
     key_ = key;
   }
 }
 HKEY RegKey::Take() {
   StopWatching();
   HKEY key = key_;
   key_ = NULL;
   return key;
 }
 bool RegKey::HasValue(const wchar_t* name) const {
   return RegQueryValueEx(key_, name, 0, NULL, NULL, NULL) == ERROR_SUCCESS;
 }
 DWORD RegKey::GetValueCount() const {
   DWORD count = 0;
   LONG result = RegQueryInfoKey(key_, NULL, 0, NULL, NULL, NULL, NULL, &count,
                                 NULL, NULL, NULL, NULL);
   return (result == ERROR_SUCCESS) ? count : 0;
 }
 LONG RegKey::GetValueNameAt(int index, std::wstring* name) const {
   wchar_t buf[256];
   DWORD bufsize = arraysize(buf);
   LONG r = ::RegEnumValue(key_, index, buf, &bufsize, NULL, NULL, NULL, NULL);
   if (r == ERROR_SUCCESS)
     *name = buf;
   return r;
 }
 LONG RegKey::DeleteKey(const wchar_t* name) {
   DCHECK(key_);
   DCHECK(name);
   LONG result = SHDeleteKey(key_, name);
   return result;
 }
 LONG RegKey::DeleteValue(const wchar_t* value_name) {
   DCHECK(key_);
   LONG result = RegDeleteValue(key_, value_name);
   return result;
 }
 LONG RegKey::ReadValueDW(const wchar_t* name, DWORD* out_value) const {
   DCHECK(out_value);
   DWORD type = REG_DWORD;
   DWORD size = sizeof(DWORD);
   DWORD local_value = 0;
   LONG result = ReadValue(name, &local_value, &size, &type);
   if (result == ERROR_SUCCESS) {
     if ((type == REG_DWORD || type == REG_BINARY) && size == sizeof(DWORD))
       *out_value = local_value;
     else
       result = ERROR_CANTREAD;
   }
   return result;
 }
 LONG RegKey::ReadInt64(const wchar_t* name, int64* out_value) const {
   DCHECK(out_value);
   DWORD type = REG_QWORD;
   int64 local_value = 0;
   DWORD size = sizeof(local_value);
   LONG result = ReadValue(name, &local_value, &size, &type);
   if (result == ERROR_SUCCESS) {
     if ((type == REG_QWORD || type == REG_BINARY) &&
         size == sizeof(local_value))
       *out_value = local_value;
     else
       result = ERROR_CANTREAD;
   }
   return result;
 }
 LONG RegKey::ReadValue(const wchar_t* name, std::wstring* out_value) const {
   DCHECK(out_value);
   const size_t kMaxStringLength = 1024;  // This is after expansion.
   // Use the one of the other forms of ReadValue if 1024 is too small for you.
   wchar_t raw_value[kMaxStringLength];
   DWORD type = REG_SZ, size = sizeof(raw_value);
   LONG result = ReadValue(name, raw_value, &size, &type);
   if (result == ERROR_SUCCESS) {
     if (type == REG_SZ) {
       *out_value = raw_value;
     } else if (type == REG_EXPAND_SZ) {
       wchar_t expanded[kMaxStringLength];
       size = ExpandEnvironmentStrings(raw_value, expanded, kMaxStringLength);
       // Success: returns the number of wchar_t's copied
       // Fail: buffer too small, returns the size required
       // Fail: other, returns 0
       if (size == 0 || size > kMaxStringLength) {
         result = ERROR_MORE_DATA;
       } else {
         *out_value = expanded;
       }
     } else {
       // Not a string. Oops.
       result = ERROR_CANTREAD;
     }
   }
   return result;
 }
 LONG RegKey::ReadValue(const wchar_t* name,
                        void* data,
                        DWORD* dsize,
                        DWORD* dtype) const {
   LONG result = RegQueryValueEx(key_, name, 0, dtype,
                                 reinterpret_cast<LPBYTE>(data), dsize);
   return result;
 }
 LONG RegKey::ReadValues(const wchar_t* name,
                         std::vector<std::wstring>* values) {
   values->clear();
   DWORD type = REG_MULTI_SZ;
   DWORD size = 0;
   LONG result = ReadValue(name, NULL, &size, &type);
   if (FAILED(result) || size == 0)
     return result;
   if (type != REG_MULTI_SZ)
     return ERROR_CANTREAD;
   std::vector<wchar_t> buffer(size / sizeof(wchar_t));
   result = ReadValue(name, &buffer[0], &size, NULL);
   if (FAILED(result) || size == 0)
     return result;
   // Parse the double-null-terminated list of strings.
   // Note: This code is paranoid to not read outside of |buf|, in the case where
   // it may not be properly terminated.
   const wchar_t* entry = &buffer[0];
   const wchar_t* buffer_end = entry + (size / sizeof(wchar_t));
   while (entry < buffer_end && entry[0] != '\0') {
     const wchar_t* entry_end = std::find(entry, buffer_end, L'\0');
     values->push_back(std::wstring(entry, entry_end));
     entry = entry_end + 1;
   }
   return 0;
 }
 LONG RegKey::WriteValue(const wchar_t* name, DWORD in_value) {
   return WriteValue(
       name, &in_value, static_cast<DWORD>(sizeof(in_value)), REG_DWORD);
 }
 LONG RegKey::WriteValue(const wchar_t * name, const wchar_t* in_value) {
   return WriteValue(name, in_value,
       static_cast<DWORD>(sizeof(*in_value) * (wcslen(in_value) + 1)), REG_SZ);
 }
 LONG RegKey::WriteValue(const wchar_t* name,
                         const void* data,
                         DWORD dsize,
                         DWORD dtype) {
   DCHECK(data || !dsize);
   LONG result = RegSetValueEx(key_, name, 0, dtype,
       reinterpret_cast<LPBYTE>(const_cast<void*>(data)), dsize);
   return result;
 }
 LONG RegKey::StartWatching() {
   DCHECK(key_);
   if (!watch_event_)
     watch_event_ = CreateEvent(NULL, TRUE, FALSE, NULL);
   DWORD filter = REG_NOTIFY_CHANGE_NAME |
                  REG_NOTIFY_CHANGE_ATTRIBUTES |
                  REG_NOTIFY_CHANGE_LAST_SET |
                  REG_NOTIFY_CHANGE_SECURITY;
   // Watch the registry key for a change of value.
   LONG result = RegNotifyChangeKeyValue(key_, TRUE, filter, watch_event_, TRUE);
   if (result != ERROR_SUCCESS) {
     CloseHandle(watch_event_);
     watch_event_ = 0;
   }
   return result;
 }
 bool RegKey::HasChanged() {
   if (watch_event_) {
     if (WaitForSingleObject(watch_event_, 0) == WAIT_OBJECT_0) {
       StartWatching();
       return true;
     }
   }
   return false;
 }
 LONG RegKey::StopWatching() {
   LONG result = ERROR_INVALID_HANDLE;
   if (watch_event_) {
     CloseHandle(watch_event_);
     watch_event_ = 0;
     result = ERROR_SUCCESS;
   }
   return result;
 }
 // RegistryValueIterator ------------------------------------------------------
 RegistryValueIterator::RegistryValueIterator(HKEY root_key,
                                              const wchar_t* folder_key)
     : name_(MAX_PATH, L'\0'),
       value_(MAX_PATH, L'\0') {
   LONG result = RegOpenKeyEx(root_key, folder_key, 0, KEY_READ, &key_);
   if (result != ERROR_SUCCESS) {
     key_ = NULL;
   } else {
     DWORD count = 0;
     result = ::RegQueryInfoKey(key_, NULL, 0, NULL, NULL, NULL, NULL, &count,
                                NULL, NULL, NULL, NULL);
     if (result != ERROR_SUCCESS) {
       ::RegCloseKey(key_);
       key_ = NULL;
     } else {
       index_ = count - 1;
     }
   }
   Read();
 }
 RegistryValueIterator::~RegistryValueIterator() {
   if (key_)
     ::RegCloseKey(key_);
 }
 DWORD RegistryValueIterator::ValueCount() const {
   DWORD count = 0;
   LONG result = ::RegQueryInfoKey(key_, NULL, 0, NULL, NULL, NULL, NULL,
                                   &count, NULL, NULL, NULL, NULL);
   if (result != ERROR_SUCCESS)
     return 0;
   return count;
 }
 bool RegistryValueIterator::Valid() const {
   return key_ != NULL && index_ >= 0;
 }
 void RegistryValueIterator::operator++() {
   --index_;
   Read();
 }
 bool RegistryValueIterator::Read() {
   if (Valid()) {
     DWORD capacity = static_cast<DWORD>(name_.capacity());
     DWORD name_size = capacity;
     // |value_size_| is in bytes. Reserve the last character for a NUL.
     value_size_ = static_cast<DWORD>((value_.size() - 1) * sizeof(wchar_t));
     LONG result = ::RegEnumValue(
         key_, index_, WriteInto(&name_, name_size), &name_size, NULL, &type_,
         reinterpret_cast<BYTE*>(vector_as_array(&value_)), &value_size_);
     if (result == ERROR_MORE_DATA) {
       // Registry key names are limited to 255 characters and fit within
       // MAX_PATH (which is 260) but registry value names can use up to 16,383
       // characters and the value itself is not limited
       // (from http://msdn.microsoft.com/en-us/library/windows/desktop/
       // ms724872(v=vs.85).aspx).
       // Resize the buffers and retry if their size caused the failure.
       DWORD value_size_in_wchars = to_wchar_size(value_size_);
       if (value_size_in_wchars + 1 > value_.size())
         value_.resize(value_size_in_wchars + 1, L'\0');
       value_size_ = static_cast<DWORD>((value_.size() - 1) * sizeof(wchar_t));
       name_size = name_size == capacity ? MAX_REGISTRY_NAME_SIZE : capacity;
       result = ::RegEnumValue(
           key_, index_, WriteInto(&name_, name_size), &name_size, NULL, &type_,
           reinterpret_cast<BYTE*>(vector_as_array(&value_)), &value_size_);
     }
     if (result == ERROR_SUCCESS) {
       DCHECK_LT(to_wchar_size(value_size_), value_.size());
       value_[to_wchar_size(value_size_)] = L'\0';
       return true;
     }
   }
   name_[0] = L'\0';
   value_[0] = L'\0';
   value_size_ = 0;
   return false;
 }
 // RegistryKeyIterator --------------------------------------------------------
 RegistryKeyIterator::RegistryKeyIterator(HKEY root_key,
                                          const wchar_t* folder_key) {
   LONG result = RegOpenKeyEx(root_key, folder_key, 0, KEY_READ, &key_);
   if (result != ERROR_SUCCESS) {
     key_ = NULL;
   } else {
     DWORD count = 0;
     LONG result = ::RegQueryInfoKey(key_, NULL, 0, NULL, &count, NULL, NULL,
                                     NULL, NULL, NULL, NULL, NULL);
     if (result != ERROR_SUCCESS) {
       ::RegCloseKey(key_);
       key_ = NULL;
     } else {
       index_ = count - 1;
     }
   }
   Read();
 }
 RegistryKeyIterator::~RegistryKeyIterator() {
   if (key_)
     ::RegCloseKey(key_);
 }
 DWORD RegistryKeyIterator::SubkeyCount() const {
   DWORD count = 0;
   LONG result = ::RegQueryInfoKey(key_, NULL, 0, NULL, &count, NULL, NULL,
                                   NULL, NULL, NULL, NULL, NULL);
   if (result != ERROR_SUCCESS)
     return 0;
   return count;
 }
 bool RegistryKeyIterator::Valid() const {
   return key_ != NULL && index_ >= 0;
 }
 void RegistryKeyIterator::operator++() {
   --index_;
   Read();
 }
 bool RegistryKeyIterator::Read() {
   if (Valid()) {
     DWORD ncount = arraysize(name_);
     FILETIME written;
     LONG r = ::RegEnumKeyEx(key_, index_, name_, &ncount, NULL, NULL,
                             NULL, &written);
     if (ERROR_SUCCESS == r)
       return true;
   }
   name_[0] = '\0';
   return false;
 }
 }  // namespace win
 }  // namespace base

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security/sandbox/chromium/base/win/registry.cc@141e0f1194b1 (annotated)

security/sandbox/chromium/base/win/registry.cc