Merge 101684 - Added CopyRegKeyWorkItem in support of IE low rights policy fixes.

chrome/installer/util/delete_reg_key_work_item.cc

 // 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/installer/util/delete_reg_key_work_item.h"
 
 #include <shlwapi.h>
-#include <algorithm>
-#include <limits>
-#include <vector>
 
 #include "base/logging.h"
-#include "base/rand_util.h"
-#include "base/stringprintf.h"
 #include "base/win/registry.h"
-#include "chrome/installer/util/logging_installer.h"
 
 using base::win::RegKey;
 
-namespace {
-const REGSAM kKeyReadNoNotify = (KEY_READ) & ~(KEY_NOTIFY);
-}
-
-// A container for a registry key, its values, and its subkeys.  We don't use
-// more obvious methods for various reasons:
-// - RegCopyTree isn't supported pre-Vista, so we'd have to do something
-//   different for XP anyway.
-// - SHCopyKey can't copy subkeys into a volatile destination, so we'd have to
-//   worry about polluting the registry.
-// We don't persist security attributes since we only delete keys that we own,
-// and we don't set custom attributes on them anyway.
-class DeleteRegKeyWorkItem::RegKeyBackup {
- public:
-  RegKeyBackup();
-  bool Initialize(const RegKey& key);
-  bool WriteTo(RegKey* key) const;
-
- private:
-  // A container for a registry value.
-  class RegValueBackup {
-   public:
-    RegValueBackup();
-    void Initialize(const wchar_t* name_buffer, DWORD name_size,
-                    DWORD type, const uint8* data, DWORD data_size);
-    const std::wstring& name_str() const { return name_; }
-    const wchar_t* name() const { return name_.empty() ? NULL : name_.c_str(); }
-    DWORD type() const { return type_; }
-    const uint8* data() const { return data_.empty() ? NULL : &data_[0]; }
-    DWORD data_len() const { return static_cast<DWORD>(data_.size()); }
-
-   private:
-    std::wstring name_;
-    std::vector<uint8> data_;
-    DWORD type_;
-
-    DISALLOW_COPY_AND_ASSIGN(RegValueBackup);
-  };
-
-  scoped_array<RegValueBackup> values_;
-  scoped_array<std::wstring> subkey_names_;
-  scoped_array<RegKeyBackup> subkeys_;
-  ptrdiff_t num_values_;
-  ptrdiff_t num_subkeys_;
-
-  DISALLOW_COPY_AND_ASSIGN(RegKeyBackup);
-};
-
-DeleteRegKeyWorkItem::RegKeyBackup::RegValueBackup::RegValueBackup()
-    : type_(REG_NONE) {
-}
-
-void DeleteRegKeyWorkItem::RegKeyBackup::RegValueBackup::Initialize(
-    const wchar_t* name_buffer,
-    DWORD name_size,
-    DWORD type, const uint8* data,
-    DWORD data_size) {
-  name_.assign(name_buffer, name_size);
-  type_ = type;
-  data_.assign(data, data + data_size);
-}
-
-DeleteRegKeyWorkItem::RegKeyBackup::RegKeyBackup()
-    : num_values_(0),
-      num_subkeys_(0) {
-}
-
-// Initializes this object by reading the values and subkeys of |key|.
-// Security descriptors are not backed up.
-bool DeleteRegKeyWorkItem::RegKeyBackup::Initialize(const RegKey& key) {
-  DCHECK(key.Valid());
-
-  scoped_array<RegValueBackup> values;
-  scoped_array<std::wstring> subkey_names;
-  scoped_array<RegKeyBackup> subkeys;
-
-  DWORD num_subkeys = 0;
-  DWORD max_subkey_name_len = 0;
-  DWORD num_values = 0;
-  DWORD max_value_name_len = 0;
-  DWORD max_value_len = 0;
-  LONG result = RegQueryInfoKey(key.Handle(), NULL, NULL, NULL,
-                                &num_subkeys, &max_subkey_name_len, NULL,
-                                &num_values, &max_value_name_len,
-                                &max_value_len, NULL, NULL);
-  if (result != ERROR_SUCCESS) {
-    LOG(ERROR) << "Failed getting info of key to backup, result: " << result;
-    return false;
-  }
-  if (max_subkey_name_len >= std::numeric_limits<DWORD>::max() - 1 ||
-      max_value_name_len >= std::numeric_limits<DWORD>::max() - 1) {
-    LOG(ERROR)
-        << "Failed backing up key; subkeys and/or names are out of range.";
-    return false;
-  }
-  DWORD max_name_len = std::max(max_subkey_name_len, max_value_name_len) + 1;
-  scoped_array<wchar_t> name_buffer(new wchar_t[max_name_len]);
-
-  // Backup the values.
-  if (num_values != 0) {
-    values.reset(new RegValueBackup[num_values]);
-    scoped_array<uint8> value_buffer(new uint8[max_value_len]);
-    DWORD name_size = 0;
-    DWORD value_type = REG_NONE;
-    DWORD value_size = 0;
-
-    for (DWORD i = 0; i < num_values; ) {
-      name_size = max_name_len;
-      value_size = max_value_len;
-      result = RegEnumValue(key.Handle(), i, name_buffer.get(), &name_size,
-                            NULL, &value_type, value_buffer.get(), &value_size);
-      switch (result) {
-        case ERROR_NO_MORE_ITEMS:
-          num_values = i;
-          break;
-        case ERROR_SUCCESS:
-          values[i].Initialize(name_buffer.get(), name_size, value_type,
-                               value_buffer.get(), value_size);
-          ++i;
-          break;
-        case ERROR_MORE_DATA:
-          if (value_size > max_value_len) {
-            max_value_len = value_size;
-            value_buffer.reset(new uint8[max_value_len]);
-          } else {
-            DCHECK(max_name_len - 1 < name_size);
-            if (name_size >= std::numeric_limits<DWORD>::max() - 1) {
-              LOG(ERROR) << "Failed backing up key; value name out of range.";
-              return false;
-            }
-            max_name_len = name_size + 1;
-            name_buffer.reset(new wchar_t[max_name_len]);
-          }
-          break;
-        default:
-          LOG(ERROR) << "Failed backing up value " << i << ", result: "
-                     << result;
-          return false;
-      }
-    }
-    DLOG_IF(WARNING, RegEnumValue(key.Handle(), num_values, name_buffer.get(),
-                                  &name_size, NULL, &value_type, NULL,
-                                  NULL) != ERROR_NO_MORE_ITEMS)
-        << "Concurrent modifications to registry key during backup operation.";
-  }
-
-  // Backup the subkeys.
-  if (num_subkeys != 0) {
-    subkey_names.reset(new std::wstring[num_subkeys]);
-    subkeys.reset(new RegKeyBackup[num_subkeys]);
-    DWORD name_size = 0;
-
-    // Get the names of them.
-    for (DWORD i = 0; i < num_subkeys; ) {
-      name_size = max_name_len;
-      result = RegEnumKeyEx(key.Handle(), i, name_buffer.get(), &name_size,
-                            NULL, NULL, NULL, NULL);
-      switch (result) {
-        case ERROR_NO_MORE_ITEMS:
-          num_subkeys = i;
-          break;
-        case ERROR_SUCCESS:
-          subkey_names[i].assign(name_buffer.get(), name_size);
-          ++i;
-          break;
-        case ERROR_MORE_DATA:
-          if (name_size >= std::numeric_limits<DWORD>::max() - 1) {
-            LOG(ERROR) << "Failed backing up key; subkey name out of range.";
-            return false;
-          }
-          max_name_len = name_size + 1;
-          name_buffer.reset(new wchar_t[max_name_len]);
-          break;
-        default:
-          LOG(ERROR) << "Failed getting name of subkey " << i
-                     << " for backup, result: " << result;
-          return false;
-      }
-    }
-    DLOG_IF(WARNING,
-            RegEnumKeyEx(key.Handle(), num_subkeys, NULL, &name_size, NULL,
-                         NULL, NULL, NULL) != ERROR_NO_MORE_ITEMS)
-        << "Concurrent modifications to registry key during backup operation.";
-
-    // Get their values.
-    RegKey subkey;
-    for (DWORD i = 0; i < num_subkeys; ++i) {
-      result = subkey.Open(key.Handle(), subkey_names[i].c_str(),
-                           kKeyReadNoNotify);
-      if (result != ERROR_SUCCESS) {
-        LOG(ERROR) << "Failed opening subkey \"" << subkey_names[i]
-                   << "\" for backup, result: " << result;
-        return false;
-      }
-      if (!subkeys[i].Initialize(subkey)) {
-        LOG(ERROR) << "Failed backing up subkey \"" << subkey_names[i] << "\"";
-        return false;
-      }
-    }
-  }
-
-  values_.swap(values);
-  subkey_names_.swap(subkey_names);
-  subkeys_.swap(subkeys);
-  num_values_ = num_values;
-  num_subkeys_ = num_subkeys;
-
-  return true;
-}
-
-// Writes the values and subkeys of this object into |key|.
-bool DeleteRegKeyWorkItem::RegKeyBackup::WriteTo(RegKey* key) const {
-  LONG result = ERROR_SUCCESS;
-
-  // Write the values.
-  for (int i = 0; i < num_values_; ++i) {
-    const RegValueBackup& value = values_[i];
-    result = RegSetValueEx(key->Handle(), value.name(), 0, value.type(),
-                           value.data(), value.data_len());
-    if (result != ERROR_SUCCESS) {
-      LOG(ERROR) << "Failed writing value \"" << value.name_str()
-                 << "\", result: " << result;
-      return false;
-    }
-  }
-
-  // Write the subkeys.
-  RegKey subkey;
-  for (int i = 0; i < num_subkeys_; ++i) {
-    const std::wstring& name = subkey_names_[i];
-
-    result = subkey.Create(key->Handle(), name.c_str(), KEY_WRITE);
-    if (result != ERROR_SUCCESS) {
-      LOG(ERROR) << "Failed creating subkey \"" << name << "\", result: "
-                 << result;
-      return false;
-    }
-    if (!subkeys_[i].WriteTo(&subkey)) {
-      LOG(ERROR) << "Failed writing subkey \"" << name << "\", result: "
-                 << result;
-      return false;
-    }
-  }
-
-  return true;
-}
-
 DeleteRegKeyWorkItem::~DeleteRegKeyWorkItem() {
 }
 
 DeleteRegKeyWorkItem::DeleteRegKeyWorkItem(HKEY predefined_root,
                                            const std::wstring& path)
     : predefined_root_(predefined_root),
       path_(path) {
+  DCHECK(predefined_root);
   // It's a safe bet that we don't want to delete one of the root trees.
   DCHECK(!path.empty());
 }
 
 bool DeleteRegKeyWorkItem::Do() {
-  scoped_ptr<RegKeyBackup> backup;
+  if (path_.empty())
+    return false;
+
+  RegistryKeyBackup backup;
 
   // Only try to make a backup if we're not configured to ignore failures.
   if (!ignore_failure_) {
-    RegKey original_key;
-
-    // Does the key exist?
-    LONG result = original_key.Open(predefined_root_, path_.c_str(),
-                                    kKeyReadNoNotify);
-    if (result == ERROR_SUCCESS) {
-      backup.reset(new RegKeyBackup());
-      if (!backup->Initialize(original_key)) {
-        LOG(ERROR) << "Failed to backup key at " << path_;
-        return ignore_failure_;
-      }
-    } else if (result != ERROR_FILE_NOT_FOUND) {
-      LOG(ERROR) << "Failed to open key at " << path_
-                 << " to create backup, result: " << result;
-      return ignore_failure_;
+    if (!backup.Initialize(predefined_root_, path_.c_str())) {
+      LOG(ERROR) << "Failed to backup destination for registry key copy.";
+      return false;
     }
   }
 
   // Delete the key.
   LONG result = SHDeleteKey(predefined_root_, path_.c_str());
   if (result != ERROR_SUCCESS && result != ERROR_FILE_NOT_FOUND) {
     LOG(ERROR) << "Failed to delete key at " << path_ << ", result: "
                << result;
     return ignore_failure_;
   }
 
   // We've succeeded, so remember any backup we may have made.
   backup_.swap(backup);
 
   return true;
 }
 
 void DeleteRegKeyWorkItem::Rollback() {
-  if (ignore_failure_ || backup_.get() == NULL)
+  if (ignore_failure_)
     return;
 
   // Delete anything in the key before restoring the backup in case someone else
   // put new data in the key after Do().
   LONG result = SHDeleteKey(predefined_root_, path_.c_str());
   if (result != ERROR_SUCCESS && result != ERROR_FILE_NOT_FOUND) {
     LOG(ERROR) << "Failed to delete key at " << path_ << " in rollback, "
                   "result: " << result;
   }
 
   // Restore the old contents.  The restoration takes on its default security
   // attributes; any custom attributes are lost.
-  RegKey original_key;
-  result = original_key.Create(predefined_root_, path_.c_str(), KEY_WRITE);
-  if (result != ERROR_SUCCESS) {
-    LOG(ERROR) << "Failed to create original key at " << path_
-               << " in rollback, result: " << result;
-  } else {
-    if (!backup_->WriteTo(&original_key))
-      LOG(ERROR) << "Failed to restore key in rollback, result: " << result;
-  }
+  if (!backup_.WriteTo(predefined_root_, path_.c_str()))
+    LOG(ERROR) << "Failed to restore key in rollback.";
 }