xref: /external/chromium_org/chrome/common/extensions/permissions/chrome_permission_message_provider.cc

// 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 "chrome/common/extensions/permissions/chrome_permission_message_provider.h"

#include "base/stl_util.h"
#include "base/strings/stringprintf.h"
#include "extensions/common/extensions_client.h"
#include "extensions/common/permissions/permission_message.h"
#include "extensions/common/permissions/permission_message_util.h"
#include "extensions/common/permissions/permission_set.h"
#include "extensions/common/url_pattern.h"
#include "extensions/common/url_pattern_set.h"
#include "grit/generated_resources.h"
#include "net/base/registry_controlled_domains/registry_controlled_domain.h"
#include "ui/base/l10n/l10n_util.h"
#include "url/gurl.h"

namespace extensions {

namespace {

typedef std::set<PermissionMessage> PermissionMsgSet;

bool ShouldWarnAllHosts(const PermissionSet* permissions) {
  if (permissions->HasEffectiveAccessToAllHosts())
    return true;

  const URLPatternSet& effective_hosts = permissions->effective_hosts();
  for (URLPatternSet::const_iterator iter = effective_hosts.begin();
       iter != effective_hosts.end();
       ++iter) {
    // If this doesn't even match subdomains, it can't possibly imply all hosts.
    if (!iter->match_subdomains())
      continue;

    // If iter->host() is a recognized TLD, this will be 0. We don't include
    // private TLDs, so that, e.g., *.appspot.com does not imply all hosts.
    size_t registry_length =
        net::registry_controlled_domains::GetRegistryLength(
            iter->host(),
            net::registry_controlled_domains::EXCLUDE_UNKNOWN_REGISTRIES,
            net::registry_controlled_domains::EXCLUDE_PRIVATE_REGISTRIES);
    // If there was more than just a TLD in the host (e.g., *.foobar.com), it
    // doesn't imply all hosts.
    if (registry_length > 0)
      continue;

    // At this point the host could either be just a TLD ("com") or some unknown
    // TLD-like string ("notatld"). To disambiguate between them construct a
    // fake URL, and check the registry. This returns 0 if the TLD is
    // unrecognized, or the length of the recognized TLD.
    registry_length = net::registry_controlled_domains::GetRegistryLength(
        base::StringPrintf("foo.%s", iter->host().c_str()),
        net::registry_controlled_domains::EXCLUDE_UNKNOWN_REGISTRIES,
        net::registry_controlled_domains::EXCLUDE_PRIVATE_REGISTRIES);
    // If we recognized this TLD, then this is a pattern like *.com, and it
    // should imply all hosts.
    if (registry_length > 0)
      return true;
  }

  return false;
}

template<typename T>
typename T::iterator FindMessageByID(T& messages, int id) {
  for (typename T::iterator it = messages.begin();
       it != messages.end(); ++it) {
    if (it->id() == id)
      return it;
  }
  return messages.end();
}

template<typename T>
void SuppressMessage(T& messages,
                     int suppressing_message,
                     int suppressed_message) {
  typename T::iterator suppressed = FindMessageByID(messages,
                                                    suppressed_message);
  if (suppressed != messages.end() &&
      FindMessageByID(messages, suppressing_message) != messages.end()) {
    messages.erase(suppressed);
  }
}

}  // namespace

ChromePermissionMessageProvider::ChromePermissionMessageProvider() {
}

ChromePermissionMessageProvider::~ChromePermissionMessageProvider() {
}

PermissionMessages ChromePermissionMessageProvider::GetPermissionMessages(
    const PermissionSet* permissions,
    Manifest::Type extension_type) const {
  PermissionMessages messages;

  if (permissions->HasEffectiveFullAccess()) {
    messages.push_back(PermissionMessage(
        PermissionMessage::kFullAccess,
        l10n_util::GetStringUTF16(IDS_EXTENSION_PROMPT_WARNING_FULL_ACCESS)));
    return messages;
  }

  PermissionMsgSet host_msgs =
      GetHostPermissionMessages(permissions, extension_type);
  PermissionMsgSet api_msgs = GetAPIPermissionMessages(permissions);
  PermissionMsgSet manifest_permission_msgs =
      GetManifestPermissionMessages(permissions);
  messages.insert(messages.end(), host_msgs.begin(), host_msgs.end());
  messages.insert(messages.end(), api_msgs.begin(), api_msgs.end());
  messages.insert(messages.end(), manifest_permission_msgs.begin(),
                  manifest_permission_msgs.end());

  // Some warnings are more generic and/or powerful and superseed other
  // warnings. In that case, suppress the superseeded warning.
  SuppressMessage(messages,
                  PermissionMessage::kBookmarks,
                  PermissionMessage::kOverrideBookmarksUI);
  // Both tabs and history already allow reading favicons.
  SuppressMessage(messages,
                  PermissionMessage::kTabs,
                  PermissionMessage::kFavicon);
  SuppressMessage(messages,
                  PermissionMessage::kBrowsingHistory,
                  PermissionMessage::kFavicon);
  // Warning for history permission already covers warning for tabs permission.
  SuppressMessage(messages,
                  PermissionMessage::kBrowsingHistory,
                  PermissionMessage::kTabs);
  return messages;
}

std::vector<base::string16> ChromePermissionMessageProvider::GetWarningMessages(
    const PermissionSet* permissions,
    Manifest::Type extension_type) const {
  std::vector<base::string16> message_strings;
  PermissionMessages messages =
      GetPermissionMessages(permissions, extension_type);

  bool audio_capture = false;
  bool video_capture = false;
  bool media_galleries_read = false;
  bool media_galleries_copy_to = false;
  bool media_galleries_delete = false;
  for (PermissionMessages::const_iterator i = messages.begin();
       i != messages.end(); ++i) {
    switch (i->id()) {
      case PermissionMessage::kAudioCapture:
        audio_capture = true;
        break;
      case PermissionMessage::kVideoCapture:
        video_capture = true;
        break;
      case PermissionMessage::kMediaGalleriesAllGalleriesRead:
        media_galleries_read = true;
        break;
      case PermissionMessage::kMediaGalleriesAllGalleriesCopyTo:
        media_galleries_copy_to = true;
        break;
      case PermissionMessage::kMediaGalleriesAllGalleriesDelete:
        media_galleries_delete = true;
        break;
      default:
        break;
    }
  }

  for (PermissionMessages::const_iterator i = messages.begin();
       i != messages.end(); ++i) {
    int id = i->id();
    if (audio_capture && video_capture) {
      if (id == PermissionMessage::kAudioCapture) {
        message_strings.push_back(l10n_util::GetStringUTF16(
            IDS_EXTENSION_PROMPT_WARNING_AUDIO_AND_VIDEO_CAPTURE));
        continue;
      } else if (id == PermissionMessage::kVideoCapture) {
        // The combined message will be pushed above.
        continue;
      }
    }
    if (media_galleries_read &&
        (media_galleries_copy_to || media_galleries_delete)) {
      if (id == PermissionMessage::kMediaGalleriesAllGalleriesRead) {
        int m_id = media_galleries_copy_to ?
            IDS_EXTENSION_PROMPT_WARNING_MEDIA_GALLERIES_READ_WRITE :
            IDS_EXTENSION_PROMPT_WARNING_MEDIA_GALLERIES_READ_DELETE;
        message_strings.push_back(l10n_util::GetStringUTF16(m_id));
        continue;
      } else if (id == PermissionMessage::kMediaGalleriesAllGalleriesCopyTo ||
                 id == PermissionMessage::kMediaGalleriesAllGalleriesDelete) {
        // The combined message will be pushed above.
        continue;
      }
    }

    message_strings.push_back(i->message());
  }

  return message_strings;
}

std::vector<base::string16>
ChromePermissionMessageProvider::GetWarningMessagesDetails(
    const PermissionSet* permissions,
    Manifest::Type extension_type) const {
  std::vector<base::string16> message_strings;
  PermissionMessages messages =
      GetPermissionMessages(permissions, extension_type);

  for (PermissionMessages::const_iterator i = messages.begin();
       i != messages.end(); ++i)
    message_strings.push_back(i->details());

  return message_strings;
}

bool ChromePermissionMessageProvider::IsPrivilegeIncrease(
    const PermissionSet* old_permissions,
    const PermissionSet* new_permissions,
    Manifest::Type extension_type) const {
  // Things can't get worse than native code access.
  if (old_permissions->HasEffectiveFullAccess())
    return false;

  // Otherwise, it's a privilege increase if the new one has full access.
  if (new_permissions->HasEffectiveFullAccess())
    return true;

  if (IsHostPrivilegeIncrease(old_permissions, new_permissions, extension_type))
    return true;

  if (IsAPIPrivilegeIncrease(old_permissions, new_permissions))
    return true;

  if (IsManifestPermissionPrivilegeIncrease(old_permissions, new_permissions))
    return true;

  return false;
}

std::set<PermissionMessage>
ChromePermissionMessageProvider::GetAPIPermissionMessages(
    const PermissionSet* permissions) const {
  PermissionMsgSet messages;
  for (APIPermissionSet::const_iterator permission_it =
           permissions->apis().begin();
       permission_it != permissions->apis().end(); ++permission_it) {
    if (permission_it->HasMessages()) {
      PermissionMessages new_messages = permission_it->GetMessages();
      messages.insert(new_messages.begin(), new_messages.end());
    }
  }

  // A special hack: If kFileSystemWriteDirectory would be displayed, hide
  // kFileSystemDirectory as the write directory message implies it.
  // TODO(sammc): Remove this. See http://crbug.com/284849.
  SuppressMessage(messages,
                  PermissionMessage::kFileSystemWriteDirectory,
                  PermissionMessage::kFileSystemDirectory);
  // A special hack: The warning message for declarativeWebRequest
  // permissions speaks about blocking parts of pages, which is a
  // subset of what the "<all_urls>" access allows. Therefore we
  // display only the "<all_urls>" warning message if both permissions
  // are required.
  if (ShouldWarnAllHosts(permissions)) {
    messages.erase(
        PermissionMessage(
            PermissionMessage::kDeclarativeWebRequest, base::string16()));
  }
  return messages;
}

std::set<PermissionMessage>
ChromePermissionMessageProvider::GetManifestPermissionMessages(
    const PermissionSet* permissions) const {
  PermissionMsgSet messages;
  for (ManifestPermissionSet::const_iterator permission_it =
           permissions->manifest_permissions().begin();
      permission_it != permissions->manifest_permissions().end();
      ++permission_it) {
    if (permission_it->HasMessages()) {
      PermissionMessages new_messages = permission_it->GetMessages();
      messages.insert(new_messages.begin(), new_messages.end());
    }
  }
  return messages;
}

std::set<PermissionMessage>
ChromePermissionMessageProvider::GetHostPermissionMessages(
    const PermissionSet* permissions,
    Manifest::Type extension_type) const {
  PermissionMsgSet messages;
  // Since platform apps always use isolated storage, they can't (silently)
  // access user data on other domains, so there's no need to prompt.
  // Note: this must remain consistent with IsHostPrivilegeIncrease.
  // See crbug.com/255229.
  if (extension_type == Manifest::TYPE_PLATFORM_APP)
    return messages;

  if (ShouldWarnAllHosts(permissions)) {
    messages.insert(PermissionMessage(
        PermissionMessage::kHostsAll,
        l10n_util::GetStringUTF16(IDS_EXTENSION_PROMPT_WARNING_ALL_HOSTS)));
  } else {
    URLPatternSet regular_hosts;
    ExtensionsClient::Get()->FilterHostPermissions(
        permissions->effective_hosts(), &regular_hosts, &messages);

    std::set<std::string> hosts =
        permission_message_util::GetDistinctHosts(regular_hosts, true, true);
    if (!hosts.empty())
      messages.insert(permission_message_util::CreateFromHostList(hosts));
  }
  return messages;
}

bool ChromePermissionMessageProvider::IsAPIPrivilegeIncrease(
    const PermissionSet* old_permissions,
    const PermissionSet* new_permissions) const {
  if (new_permissions == NULL)
    return false;

  PermissionMsgSet old_warnings = GetAPIPermissionMessages(old_permissions);
  PermissionMsgSet new_warnings = GetAPIPermissionMessages(new_permissions);
  PermissionMsgSet delta_warnings =
      base::STLSetDifference<PermissionMsgSet>(new_warnings, old_warnings);

  // A special hack: kFileSystemWriteDirectory implies kFileSystemDirectory.
  // TODO(sammc): Remove this. See http://crbug.com/284849.
  if (old_warnings.find(PermissionMessage(
          PermissionMessage::kFileSystemWriteDirectory, base::string16())) !=
      old_warnings.end()) {
    delta_warnings.erase(
        PermissionMessage(PermissionMessage::kFileSystemDirectory,
                          base::string16()));
  }

  // It is a privilege increase if there are additional warnings present.
  return !delta_warnings.empty();
}

bool ChromePermissionMessageProvider::IsManifestPermissionPrivilegeIncrease(
    const PermissionSet* old_permissions,
    const PermissionSet* new_permissions) const {
  if (new_permissions == NULL)
    return false;

  PermissionMsgSet old_warnings =
      GetManifestPermissionMessages(old_permissions);
  PermissionMsgSet new_warnings =
      GetManifestPermissionMessages(new_permissions);
  PermissionMsgSet delta_warnings =
      base::STLSetDifference<PermissionMsgSet>(new_warnings, old_warnings);

  // It is a privilege increase if there are additional warnings present.
  return !delta_warnings.empty();
}

bool ChromePermissionMessageProvider::IsHostPrivilegeIncrease(
    const PermissionSet* old_permissions,
    const PermissionSet* new_permissions,
    Manifest::Type extension_type) const {
  // Platform apps host permission changes do not count as privilege increases.
  // Note: this must remain consistent with GetHostPermissionMessages.
  if (extension_type == Manifest::TYPE_PLATFORM_APP)
    return false;

  // If the old permission set can access any host, then it can't be elevated.
  if (old_permissions->HasEffectiveAccessToAllHosts())
    return false;

  // Likewise, if the new permission set has full host access, then it must be
  // a privilege increase.
  if (new_permissions->HasEffectiveAccessToAllHosts())
    return true;

  const URLPatternSet& old_list = old_permissions->effective_hosts();
  const URLPatternSet& new_list = new_permissions->effective_hosts();

  // TODO(jstritar): This is overly conservative with respect to subdomains.
  // For example, going from *.google.com to www.google.com will be
  // considered an elevation, even though it is not (http://crbug.com/65337).
  std::set<std::string> new_hosts_set(
      permission_message_util::GetDistinctHosts(new_list, false, false));
  std::set<std::string> old_hosts_set(
      permission_message_util::GetDistinctHosts(old_list, false, false));
  std::set<std::string> new_hosts_only =
      base::STLSetDifference<std::set<std::string> >(new_hosts_set,
                                                     old_hosts_set);

  return !new_hosts_only.empty();
}

}  // namespace extensions