text: // Copyright 2013 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 "components/policy/core/common/registry_dict.h"
  
  #include <utility>
  
  #include "base/json/json_reader.h"
  #include "base/memory/ptr_util.h"
  #include "base/strings/string_number_conversions.h"
  #include "base/strings/string_util.h"
  #include "base/strings/utf_string_conversions.h"
  #include "base/sys_byteorder.h"
  #include "base/values.h"
  
  #if defined(OS_WIN)
  #include "base/win/registry.h"
  #include "components/policy/core/common/schema.h"
  
  using base::win::RegistryKeyIterator;
  using base::win::RegistryValueIterator;
  #endif  // #if defined(OS_WIN)
  
  namespace policy {
  
  namespace {
  
  #if defined(OS_WIN)
  // Validates that a key is numerical. Used for lists below.
  bool IsKeyNumerical(const std::string& key) {
    int temp = 0;
    return base::StringToInt(key, &temp);
  }
  
  // Converts a value (as read from the registry) to meet |schema|, converting
  // types as necessary. Unconvertible types will show up as null values in the
  // result.
  std::unique_ptr<base::Value> ConvertValue(const base::Value& value,
                                            const Schema& schema) {
    if (!schema.valid())
      return value.CreateDeepCopy();
  
    // If the type is good already, go with it.
    if (value.IsType(schema.type())) {
      // Recurse for complex types.
      const base::DictionaryValue* dict = nullptr;
      const base::ListValue* list = nullptr;
      if (value.GetAsDictionary(&dict)) {
        std::unique_ptr<base::DictionaryValue> result(
            new base::DictionaryValue());
        for (base::DictionaryValue::Iterator entry(*dict); !entry.IsAtEnd();
             entry.Advance()) {
          std::unique_ptr<base::Value> converted =
              ConvertValue(entry.value(), schema.GetProperty(entry.key()));
          if (converted)
            result->SetWithoutPathExpansion(entry.key(), std::move(converted));
        }
        return std::move(result);
      } else if (value.GetAsList(&list)) {
        std::unique_ptr<base::ListValue> result(new base::ListValue());
        for (base::ListValue::const_iterator entry(list->begin());
             entry != list->end(); ++entry) {
          std::unique_ptr<base::Value> converted =
              ConvertValue(*entry, schema.GetItems());
          if (converted)
            result->Append(std::move(converted));
        }
        return std::move(result);
      }
      return value.CreateDeepCopy();
    }
  
    // Else, do some conversions to map windows registry data types to JSON types.
    std::string string_value;
    int int_value = 0;
    switch (schema.type()) {
      case base::Value::Type::NONE: {
        return base::MakeUnique<base::Value>();
      }
      case base::Value::Type::BOOLEAN: {
        // Accept booleans encoded as either string or integer.
        if (value.GetAsInteger(&int_value) ||
            (value.GetAsString(&string_value) &&
             base::StringToInt(string_value, &int_value))) {
          return std::unique_ptr<base::Value>(new base::Value(int_value != 0));
        }
        break;
      }
      case base::Value::Type::INTEGER: {
        // Integers may be string-encoded.
        if (value.GetAsString(&string_value) &&
            base::StringToInt(string_value, &int_value)) {
          return std::unique_ptr<base::Value>(new base::Value(int_value));
        }
        break;
      }
      case base::Value::Type::DOUBLE: {
        // Doubles may be string-encoded or integer-encoded.
        double double_value = 0;
        if (value.GetAsDouble(&double_value) ||
            (value.GetAsString(&string_value) &&
             base::StringToDouble(string_value, &double_value))) {
          return std::unique_ptr<base::Value>(new base::Value(double_value));
        }
        break;
      }
      case base::Value::Type::LIST: {
        // Lists are encoded as subkeys with numbered value in the registry
        // (non-numerical keys are ignored).
        const base::DictionaryValue* dict = nullptr;
        if (value.GetAsDictionary(&dict)) {
          std::unique_ptr<base::ListValue> result(new base::ListValue());
          for (base::DictionaryValue::Iterator it(*dict); !it.IsAtEnd();
               it.Advance()) {
            if (!IsKeyNumerical(it.key()))
              continue;
            std::unique_ptr<base::Value> converted =
                ConvertValue(it.value(), schema.GetItems());
            if (converted)
              result->Append(std::move(converted));
          }
          return std::move(result);
        }
        // Fall through in order to accept lists encoded as JSON strings.
      }
      case base::Value::Type::DICTIONARY: {
        // Dictionaries may be encoded as JSON strings.
        if (value.GetAsString(&string_value)) {
          std::unique_ptr<base::Value> result =
              base::JSONReader::Read(string_value);
          if (result && result->IsType(schema.type()))
            return result;
        }
        break;
      }
      case base::Value::Type::STRING:
      case base::Value::Type::BINARY:
        // No conversion possible.
        break;
    }
  
    LOG(WARNING) << "Failed to convert " << value.GetType()
                 << " to " << schema.type();
    return nullptr;
  }
  #endif  // #if defined(OS_WIN)
  
  }  // namespace
  
  bool CaseInsensitiveStringCompare::operator()(const std::string& a,
                                                const std::string& b) const {
    return base::CompareCaseInsensitiveASCII(a, b) < 0;
  }
  
  RegistryDict::RegistryDict() {}
  
  RegistryDict::~RegistryDict() {
    ClearKeys();
    ClearValues();
  }
  
  RegistryDict* RegistryDict::GetKey(const std::string& name) {
    KeyMap::iterator entry = keys_.find(name);
    return entry != keys_.end() ? entry->second.get() : nullptr;
  }
  
  const RegistryDict* RegistryDict::GetKey(const std::string& name) const {
    KeyMap::const_iterator entry = keys_.find(name);
    return entry != keys_.end() ? entry->second.get() : nullptr;
  }
  
  void RegistryDict::SetKey(const std::string& name,
                            std::unique_ptr<RegistryDict> dict) {
    if (!dict) {
      RemoveKey(name);
      return;
    }
  
    keys_[name] = std::move(dict);
  }
  
  std::unique_ptr<RegistryDict> RegistryDict::RemoveKey(const std::string& name) {
    std::unique_ptr<RegistryDict> result;
    KeyMap::iterator entry = keys_.find(name);
    if (entry != keys_.end()) {
      result = std::move(entry->second);
      keys_.erase(entry);
    }
    return result;
  }
  
  void RegistryDict::ClearKeys() {
    keys_.clear();
  }
  
  base::Value* RegistryDict::GetValue(const std::string& name) {
    ValueMap::iterator entry = values_.find(name);
    return entry != values_.end() ? entry->second.get() : nullptr;
  }
  
  const base::Value* RegistryDict::GetValue(const std::string& name) const {
    ValueMap::const_iterator entry = values_.find(name);
    return entry != values_.end() ? entry->second.get() : nullptr;
  }
  
  void RegistryDict::SetValue(const std::string& name,
                              std::unique_ptr<base::Value> dict) {
    if (!dict) {
      RemoveValue(name);
      return;
    }
  
    values_[name] = std::move(dict);
  }
  
  std::unique_ptr<base::Value> RegistryDict::RemoveValue(
      const std::string& name) {
    std::unique_ptr<base::Value> result;
    ValueMap::iterator entry = values_.find(name);
    if (entry != values_.end()) {
      result = std::move(entry->second);
      values_.erase(entry);
    }
    return result;
  }
  
  void RegistryDict::ClearValues() {
    values_.clear();
  }
  
  void RegistryDict::Merge(const RegistryDict& other) {
    for (KeyMap::const_iterator entry(other.keys_.begin());
         entry != other.keys_.end(); ++entry) {
      std::unique_ptr<RegistryDict>& subdict = keys_[entry->first];
      if (!subdict)
        subdict = base::MakeUnique<RegistryDict>();
      subdict->Merge(*entry->second);
    }
  
    for (ValueMap::const_iterator entry(other.values_.begin());
         entry != other.values_.end(); ++entry) {
      SetValue(entry->first, entry->second->CreateDeepCopy());
    }
  }
  
  void RegistryDict::Swap(RegistryDict* other) {
    keys_.swap(other->keys_);
    values_.swap(other->values_);
  }
  
  #if defined(OS_WIN)
  void RegistryDict::ReadRegistry(HKEY hive, const base::string16& root) {
    ClearKeys();
    ClearValues();
  
    // First, read all the values of the key.
    for (RegistryValueIterator it(hive, root.c_str()); it.Valid(); ++it) {
      const std::string name = base::UTF16ToUTF8(it.Name());
      switch (it.Type()) {
        case REG_SZ:
        case REG_EXPAND_SZ:
          SetValue(name, std::unique_ptr<base::Value>(
                             new base::Value(base::UTF16ToUTF8(it.Value()))));
          continue;
        case REG_DWORD_LITTLE_ENDIAN:
        case REG_DWORD_BIG_ENDIAN:
          if (it.ValueSize() == sizeof(DWORD)) {
            DWORD dword_value = *(reinterpret_cast<const DWORD*>(it.Value()));
            if (it.Type() == REG_DWORD_BIG_ENDIAN)
              dword_value = base::NetToHost32(dword_value);
            else
              dword_value = base::ByteSwapToLE32(dword_value);
            SetValue(name, std::unique_ptr<base::Value>(
                               new base::Value(static_cast<int>(dword_value))));
            continue;
          }
        case REG_NONE:
        case REG_LINK:
        case REG_MULTI_SZ:
        case REG_RESOURCE_LIST:
        case REG_FULL_RESOURCE_DESCRIPTOR:
        case REG_RESOURCE_REQUIREMENTS_LIST:
        case REG_QWORD_LITTLE_ENDIAN:
          // Unsupported type, message gets logged below.
          break;
      }
  
      LOG(WARNING) << "Failed to read hive " << hive << " at "
                   << root << "\\" << name
                   << " type " << it.Type();
    }
  
    // Recurse for all subkeys.
    for (RegistryKeyIterator it(hive, root.c_str()); it.Valid(); ++it) {
      std::string name(base::UTF16ToUTF8(it.Name()));
      std::unique_ptr<RegistryDict> subdict(new RegistryDict());
      subdict->ReadRegistry(hive, root + L"\\" + it.Name());
      SetKey(name, std::move(subdict));
    }
  }
  
  std::unique_ptr<base::Value> RegistryDict::ConvertToJSON(
      const Schema& schema) const {
    base::Value::Type type =
        schema.valid() ? schema.type() : base::Value::Type::DICTIONARY;
    switch (type) {
      case base::Value::Type::DICTIONARY: {
        std::unique_ptr<base::DictionaryValue> result(
            new base::DictionaryValue());
        for (RegistryDict::ValueMap::const_iterator entry(values_.begin());
             entry != values_.end(); ++entry) {
          Schema subschema =
              schema.valid() ? schema.GetProperty(entry->first) : Schema();
          std::unique_ptr<base::Value> converted =
              ConvertValue(*entry->second, subschema);
          if (converted)
            result->SetWithoutPathExpansion(entry->first, std::move(converted));
        }
        for (RegistryDict::KeyMap::const_iterator entry(keys_.begin());
             entry != keys_.end(); ++entry) {
          Schema subschema =
              schema.valid() ? schema.GetProperty(entry->first) : Schema();
          std::unique_ptr<base::Value> converted =
              entry->second->ConvertToJSON(subschema);
          if (converted)
            result->SetWithoutPathExpansion(entry->first, std::move(converted));
        }
        return std::move(result);
      }
      case base::Value::Type::LIST: {
        std::unique_ptr<base::ListValue> result(new base::ListValue());
        Schema item_schema = schema.valid() ? schema.GetItems() : Schema();
        for (RegistryDict::KeyMap::const_iterator entry(keys_.begin());
             entry != keys_.end(); ++entry) {
          if (!IsKeyNumerical(entry->first))
            continue;
          std::unique_ptr<base::Value> converted =
              entry->second->ConvertToJSON(item_schema);
          if (converted)
            result->Append(std::move(converted));
        }
        for (RegistryDict::ValueMap::const_iterator entry(values_.begin());
             entry != values_.end(); ++entry) {
          if (!IsKeyNumerical(entry->first))
            continue;
          std::unique_ptr<base::Value> converted =
              ConvertValue(*entry->second, item_schema);
          if (converted)
            result->Append(std::move(converted));
        }
        return std::move(result);
      }
      default:
        LOG(WARNING) << "Can't convert registry key to schema type " << type;
    }
  
    return nullptr;
  }
  #endif  // #if defined(OS_WIN)
  }  // namespace policy
  