Linux: add library loader for GNOME keyring.

chrome/browser/password_manager/native_backend_gnome_x.cc

 // 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 "chrome/browser/password_manager/native_backend_gnome_x.h"
 
-#include <dlfcn.h>
-#include <gnome-keyring.h>
-
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/logging.h"
 #include "base/string_number_conversions.h"
 #include "base/string_piece.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "base/synchronization/waitable_event.h"
+#include "base/threading/thread_restrictions.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 #include "content/public/browser/browser_thread.h"
 
 using content::BrowserThread;
 using content::PasswordForm;
 
-#define GNOME_KEYRING_DEFINE_POINTER(name) \
-  typeof(&::gnome_keyring_##name) GnomeKeyringLoader::gnome_keyring_##name;
-GNOME_KEYRING_FOR_EACH_FUNC(GNOME_KEYRING_DEFINE_POINTER)
-#undef GNOME_KEYRING_DEFINE_POINTER
-
-bool GnomeKeyringLoader::keyring_loaded = false;
-
-#if defined(DLOPEN_GNOME_KEYRING)
-
-#define GNOME_KEYRING_FUNCTION_INFO(name) \
-  {"gnome_keyring_"#name, reinterpret_cast<void**>(&gnome_keyring_##name)},
-const GnomeKeyringLoader::FunctionInfo GnomeKeyringLoader::functions[] = {
-  GNOME_KEYRING_FOR_EACH_FUNC(GNOME_KEYRING_FUNCTION_INFO)
-  {NULL, NULL}
-};
-#undef GNOME_KEYRING_FUNCTION_INFO
-
-/* Load the library and initialize the function pointers. */
-bool GnomeKeyringLoader::LoadGnomeKeyring() {
-  if (keyring_loaded)
-    return true;
-
-  void* handle = dlopen("libgnome-keyring.so.0", RTLD_NOW | RTLD_GLOBAL);
-  if (!handle) {
-    // We wanted to use GNOME Keyring, but we couldn't load it. Warn, because
-    // either the user asked for this, or we autodetected it incorrectly. (Or
-    // the system has broken libraries, which is also good to warn about.)
-    LOG(WARNING) << "Could not load libgnome-keyring.so.0: " << dlerror();
-    return false;
-  }
-
-  for (size_t i = 0; functions[i].name; ++i) {
-    dlerror();
-    *functions[i].pointer = dlsym(handle, functions[i].name);
-    const char* error = dlerror();
-    if (error) {
-      LOG(ERROR) << "Unable to load symbol "
-                 << functions[i].name << ": " << error;
-      dlclose(handle);
-      return false;
-    }
-  }
-
-  keyring_loaded = true;
-  // We leak the library handle. That's OK: this function is called only once.
-  return true;
-}
-
-#else  // defined(DLOPEN_GNOME_KEYRING)
-
-bool GnomeKeyringLoader::LoadGnomeKeyring() {
-  if (keyring_loaded)
-    return true;
-#define GNOME_KEYRING_ASSIGN_POINTER(name) \
-  gnome_keyring_##name = &::gnome_keyring_##name;
-  GNOME_KEYRING_FOR_EACH_FUNC(GNOME_KEYRING_ASSIGN_POINTER)
-#undef GNOME_KEYRING_ASSIGN_POINTER
-  keyring_loaded = true;
-  return true;
-}
-
-#endif  // defined(DLOPEN_GNOME_KEYRING)
-
 namespace {
 
 const char kGnomeKeyringAppString[] = "chrome";
 
 // Convert the attributes of a given keyring entry into a new PasswordForm.
 // Note: does *not* get the actual password, as that is not a key attribute!
 // Returns NULL if the attributes are for the wrong application.
 PasswordForm* FormFromAttributes(GnomeKeyringAttributeList* attrs) {
   // Read the string and int attributes into the appropriate map.
   std::map<std::string, std::string> string_attr_map;
   std::map<std::string, uint32_t> uint_attr_map;
   for (guint i = 0; i < attrs->len; ++i) {
+    // Note: gnome_keyring_attribute_list_index below is a macro
+    // and not a function call.
     GnomeKeyringAttribute attr = gnome_keyring_attribute_list_index(attrs, i);
     if (attr.type == GNOME_KEYRING_ATTRIBUTE_TYPE_STRING)
       string_attr_map[attr.name] = attr.value.string;
     else if (attr.type == GNOME_KEYRING_ATTRIBUTE_TYPE_UINT32)
       uint_attr_map[attr.name] = attr.value.integer;
   }
   // Check to make sure this is a password we care about.
   const std::string& app_value = string_attr_map["application"];
   if (!base::StringPiece(app_value).starts_with(kGnomeKeyringAppString))
     return NULL;
@@ skipping 75 matching lines @@
 // caller, e.g. in the password management UI), and *block* the DB thread
 // waiting for a response from the UI thread to provide the synchronous API
 // PasswordStore expects of us. (It will then in turn switch back to the
 // original caller to send the asynchronous reply to the original request.)
 
 // This class represents a call to a GNOME Keyring method. A RunnableMethod
 // should be posted to the UI thread to call one of its action methods, and then
 // a WaitResult() method should be called to wait for the result. Each instance
 // supports only one outstanding method at a time, though multiple instances may
 // be used in parallel.
-class GKRMethod : public GnomeKeyringLoader {
+class GKRMethod {
  public:
   typedef NativeBackendGnome::PasswordFormList PasswordFormList;
 
-  GKRMethod() : event_(false, false), result_(GNOME_KEYRING_RESULT_CANCELLED) {}
+  explicit GKRMethod(const LibGnomeKeyringLoader* loader)
+      : loader_(loader),
+        event_(false, false),
+        result_(GNOME_KEYRING_RESULT_CANCELLED) {
+  }
 
   // Action methods. These call gnome_keyring_* functions. Call from UI thread.
   // See GetProfileSpecificAppString() for more information on the app string.
   void AddLogin(const PasswordForm& form, const char* app_string);
   void AddLoginSearch(const PasswordForm& form, const char* app_string);
   void UpdateLoginSearch(const PasswordForm& form, const char* app_string);
   void RemoveLogin(const PasswordForm& form, const char* app_string);
   void GetLogins(const PasswordForm& form, const char* app_string);
   void GetLoginsList(uint32_t blacklisted_by_user, const char* app_string);
   void GetAllLogins(const char* app_string);
 
   // Use after AddLogin, RemoveLogin.
   GnomeKeyringResult WaitResult();
 
   // Use after AddLoginSearch, UpdateLoginSearch, GetLogins, GetLoginsList,
   // GetAllLogins.
   GnomeKeyringResult WaitResult(PasswordFormList* forms);
 
  private:
   // All these callbacks are called on UI thread.
   static void OnOperationDone(GnomeKeyringResult result, gpointer data);
 
   static void OnOperationGetList(GnomeKeyringResult result, GList* list,
                                  gpointer data);
 
+  const LibGnomeKeyringLoader* loader_;
+
   base::WaitableEvent event_;
   GnomeKeyringResult result_;
   NativeBackendGnome::PasswordFormList forms_;
 };
 
 void GKRMethod::AddLogin(const PasswordForm& form, const char* app_string) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   time_t date_created = form.date_created.ToTimeT();
   // If we are asked to save a password with 0 date, use the current time.
   // We don't want to actually save passwords as though on January 1, 1970.
   if (!date_created)
     date_created = time(NULL);
-  gnome_keyring_store_password(
+  loader_->gnome_keyring_store_password(
       &kGnomeSchema,
       NULL,  // Default keyring.
       form.origin.spec().c_str(),  // Display name.
       UTF16ToUTF8(form.password_value).c_str(),
       OnOperationDone,
       this,  // data
       NULL,  // destroy_data
       "origin_url", form.origin.spec().c_str(),
       "action_url", form.action.spec().c_str(),
       "username_element", UTF16ToUTF8(form.username_element).c_str(),
       "username_value", UTF16ToUTF8(form.username_value).c_str(),
       "password_element", UTF16ToUTF8(form.password_element).c_str(),
       "submit_element", UTF16ToUTF8(form.submit_element).c_str(),
       "signon_realm", form.signon_realm.c_str(),
       "ssl_valid", form.ssl_valid,
       "preferred", form.preferred,
       "date_created", base::Int64ToString(date_created).c_str(),
       "blacklisted_by_user", form.blacklisted_by_user,
       "scheme", form.scheme,
       "application", app_string,
       NULL);
 }
 
 void GKRMethod::AddLoginSearch(const PasswordForm& form,
                                const char* app_string) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   // Search GNOME Keyring for matching passwords to update.
-  gnome_keyring_find_itemsv(
+  loader_->gnome_keyring_find_itemsv(
       GNOME_KEYRING_ITEM_GENERIC_SECRET,
       OnOperationGetList,
       this,  // data
       NULL,  // destroy_data
       "origin_url", GNOME_KEYRING_ATTRIBUTE_TYPE_STRING,
       form.origin.spec().c_str(),
       "username_element", GNOME_KEYRING_ATTRIBUTE_TYPE_STRING,
       UTF16ToUTF8(form.username_element).c_str(),
       "username_value", GNOME_KEYRING_ATTRIBUTE_TYPE_STRING,
       UTF16ToUTF8(form.username_value).c_str(),
       "password_element", GNOME_KEYRING_ATTRIBUTE_TYPE_STRING,
       UTF16ToUTF8(form.password_element).c_str(),
       "submit_element", GNOME_KEYRING_ATTRIBUTE_TYPE_STRING,
       UTF16ToUTF8(form.submit_element).c_str(),
       "signon_realm", GNOME_KEYRING_ATTRIBUTE_TYPE_STRING,
       form.signon_realm.c_str(),
       "application", GNOME_KEYRING_ATTRIBUTE_TYPE_STRING,
       app_string,
       NULL);
 }
 
 void GKRMethod::UpdateLoginSearch(const PasswordForm& form,
                                   const char* app_string) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   // Search GNOME Keyring for matching passwords to update.
-  gnome_keyring_find_itemsv(
+  loader_->gnome_keyring_find_itemsv(
       GNOME_KEYRING_ITEM_GENERIC_SECRET,
       OnOperationGetList,
       this,  // data
       NULL,  // destroy_data
       "origin_url", GNOME_KEYRING_ATTRIBUTE_TYPE_STRING,
       form.origin.spec().c_str(),
       "username_element", GNOME_KEYRING_ATTRIBUTE_TYPE_STRING,
       UTF16ToUTF8(form.username_element).c_str(),
       "username_value", GNOME_KEYRING_ATTRIBUTE_TYPE_STRING,
       UTF16ToUTF8(form.username_value).c_str(),
       "password_element", GNOME_KEYRING_ATTRIBUTE_TYPE_STRING,
       UTF16ToUTF8(form.password_element).c_str(),
       "signon_realm", GNOME_KEYRING_ATTRIBUTE_TYPE_STRING,
       form.signon_realm.c_str(),
       "application", GNOME_KEYRING_ATTRIBUTE_TYPE_STRING,
       app_string,
       NULL);
 }
 
 void GKRMethod::RemoveLogin(const PasswordForm& form, const char* app_string) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   // We find forms using the same fields as LoginDatabase::RemoveLogin().
-  gnome_keyring_delete_password(
+  loader_->gnome_keyring_delete_password(
       &kGnomeSchema,
       OnOperationDone,
       this,  // data
       NULL,  // destroy_data
       "origin_url", form.origin.spec().c_str(),
       "action_url", form.action.spec().c_str(),
       "username_element", UTF16ToUTF8(form.username_element).c_str(),
       "username_value", UTF16ToUTF8(form.username_value).c_str(),
       "password_element", UTF16ToUTF8(form.password_element).c_str(),
       "submit_element", UTF16ToUTF8(form.submit_element).c_str(),
       "signon_realm", form.signon_realm.c_str(),
       "application", app_string,
       NULL);
 }
 
 void GKRMethod::GetLogins(const PasswordForm& form, const char* app_string) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   // Search GNOME Keyring for matching passwords.
-  gnome_keyring_find_itemsv(
+  loader_->gnome_keyring_find_itemsv(
       GNOME_KEYRING_ITEM_GENERIC_SECRET,
       OnOperationGetList,
       this,  // data
       NULL,  // destroy_data
       "signon_realm", GNOME_KEYRING_ATTRIBUTE_TYPE_STRING,
       form.signon_realm.c_str(),
       "application", GNOME_KEYRING_ATTRIBUTE_TYPE_STRING,
       app_string,
       NULL);
 }
 
 void GKRMethod::GetLoginsList(uint32_t blacklisted_by_user,
                               const char* app_string) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   // Search GNOME Keyring for matching passwords.
-  gnome_keyring_find_itemsv(
+  loader_->gnome_keyring_find_itemsv(
       GNOME_KEYRING_ITEM_GENERIC_SECRET,
       OnOperationGetList,
       this,  // data
       NULL,  // destroy_data
       "blacklisted_by_user", GNOME_KEYRING_ATTRIBUTE_TYPE_UINT32,
       blacklisted_by_user,
       "application", GNOME_KEYRING_ATTRIBUTE_TYPE_STRING,
       app_string,
       NULL);
 }
 
 void GKRMethod::GetAllLogins(const char* app_string) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   // We need to search for something, otherwise we get no results - so
   // we search for the fixed application string.
-  gnome_keyring_find_itemsv(
+  loader_->gnome_keyring_find_itemsv(
       GNOME_KEYRING_ITEM_GENERIC_SECRET,
       OnOperationGetList,
       this,  // data
       NULL,  // destroy_data
       "application", GNOME_KEYRING_ATTRIBUTE_TYPE_STRING,
       app_string,
       NULL);
 }
 
 GnomeKeyringResult GKRMethod::WaitResult() {
@@ skipping 48 matching lines @@
   } else {
     app_string_ = kGnomeKeyringAppString;
     migrate_tried_ = false;
   }
 }
 
 NativeBackendGnome::~NativeBackendGnome() {
 }
 
 bool NativeBackendGnome::Init() {
-  return LoadGnomeKeyring() && gnome_keyring_is_available();
+  // TODO(phajdan.jr): Redesign the code to load library on different thread.
+  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  return libgnome_keyring_loader_.Load("libgnome-keyring.so.0") &&
+      libgnome_keyring_loader_.gnome_keyring_is_available();
 }
 
 bool NativeBackendGnome::RawAddLogin(const PasswordForm& form) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::DB));
-  GKRMethod method;
+  GKRMethod method(&libgnome_keyring_loader_);
   BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
                           base::Bind(&GKRMethod::AddLogin,
                                      base::Unretained(&method),
                                      form, app_string_.c_str()));
   GnomeKeyringResult result = method.WaitResult();
   if (result != GNOME_KEYRING_RESULT_OK) {
     LOG(ERROR) << "Keyring save failed: "
-               << gnome_keyring_result_to_message(result);
+               << libgnome_keyring_loader_.gnome_keyring_result_to_message(
+                   result);
     return false;
   }
   // Successful write. Try migration if necessary.
   if (!migrate_tried_)
     MigrateToProfileSpecificLogins();
   return true;
 }
 
 bool NativeBackendGnome::AddLogin(const PasswordForm& form) {
   // Based on LoginDatabase::AddLogin(), we search for an existing match based
   // on origin_url, username_element, username_value, password_element, submit
   // element, and signon_realm first, remove that, and then add the new entry.
   // We'd add the new one first, and then delete the original, but then the
   // delete might actually delete the newly-added entry!
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::DB));
-  GKRMethod method;
+  GKRMethod method(&libgnome_keyring_loader_);
   BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
                           base::Bind(&GKRMethod::AddLoginSearch,
                                      base::Unretained(&method),
                                      form, app_string_.c_str()));
   PasswordFormList forms;
   GnomeKeyringResult result = method.WaitResult(&forms);
   if (result != GNOME_KEYRING_RESULT_OK &&
       result != GNOME_KEYRING_RESULT_NO_MATCH) {
     LOG(ERROR) << "Keyring find failed: "
-               << gnome_keyring_result_to_message(result);
+               << libgnome_keyring_loader_.gnome_keyring_result_to_message(
+                   result);
     return false;
   }
   if (forms.size() > 0) {
     if (forms.size() > 1) {
       LOG(WARNING) << "Adding login when there are " << forms.size()
                    << " matching logins already! Will replace only the first.";
     }
 
     // We try migration before updating the existing logins, since otherwise
     // we'd do it after making some but not all of the changes below.
     if (forms.size() > 0 && !migrate_tried_)
       MigrateToProfileSpecificLogins();
 
     RemoveLogin(*forms[0]);
     for (size_t i = 0; i < forms.size(); ++i)
       delete forms[i];
   }
   return RawAddLogin(form);
 }
 
 bool NativeBackendGnome::UpdateLogin(const PasswordForm& form) {
   // Based on LoginDatabase::UpdateLogin(), we search for forms to update by
   // origin_url, username_element, username_value, password_element, and
   // signon_realm. We then compare the result to the updated form. If they
   // differ in any of the action, password_value, ssl_valid, or preferred
   // fields, then we remove the original, and then add the new entry. We'd add
   // the new one first, and then delete the original, but then the delete might
   // actually delete the newly-added entry!
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::DB));
-  GKRMethod method;
+  GKRMethod method(&libgnome_keyring_loader_);
   BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
                           base::Bind(&GKRMethod::UpdateLoginSearch,
                                      base::Unretained(&method),
                                      form, app_string_.c_str()));
   PasswordFormList forms;
   GnomeKeyringResult result = method.WaitResult(&forms);
   if (result != GNOME_KEYRING_RESULT_OK) {
     LOG(ERROR) << "Keyring find failed: "
-               << gnome_keyring_result_to_message(result);
+               << libgnome_keyring_loader_.gnome_keyring_result_to_message(
+                   result);
     return false;
   }
 
   // We try migration before updating the existing logins, since otherwise
   // we'd do it after making some but not all of the changes below.
   if (forms.size() > 0 && !migrate_tried_)
     MigrateToProfileSpecificLogins();
 
   bool ok = true;
   for (size_t i = 0; i < forms.size(); ++i) {
@@ skipping 16 matching lines @@
       if (!RawAddLogin(*forms[i]))
         ok = false;
     }
     delete forms[i];
   }
   return ok;
 }
 
 bool NativeBackendGnome::RemoveLogin(const PasswordForm& form) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::DB));
-  GKRMethod method;
+  GKRMethod method(&libgnome_keyring_loader_);
   BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
                           base::Bind(&GKRMethod::RemoveLogin,
                                      base::Unretained(&method),
                                      form, app_string_.c_str()));
   GnomeKeyringResult result = method.WaitResult();
   if (result != GNOME_KEYRING_RESULT_OK) {
     // Warning, not error, because this can sometimes happen due to the user
     // racing with the daemon to delete the password a second time.
     LOG(WARNING) << "Keyring delete failed: "
-                 << gnome_keyring_result_to_message(result);
+                 << libgnome_keyring_loader_.gnome_keyring_result_to_message(
+                     result);
     return false;
   }
   // Successful write. Try migration if necessary. Note that presumably if we've
   // been asked to delete a login, it's because we returned it previously; thus,
   // this will probably never happen since we'd have already tried migration.
   if (!migrate_tried_)
     MigrateToProfileSpecificLogins();
   return true;
 }
 
@@ skipping 16 matching lines @@
         ok = false;
     }
     delete forms[i];
   }
   return ok;
 }
 
 bool NativeBackendGnome::GetLogins(const PasswordForm& form,
                                    PasswordFormList* forms) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::DB));
-  GKRMethod method;
+  GKRMethod method(&libgnome_keyring_loader_);
   BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
                           base::Bind(&GKRMethod::GetLogins,
                                      base::Unretained(&method),
                                      form, app_string_.c_str()));
   GnomeKeyringResult result = method.WaitResult(forms);
   if (result == GNOME_KEYRING_RESULT_NO_MATCH)
     return true;
   if (result != GNOME_KEYRING_RESULT_OK) {
     LOG(ERROR) << "Keyring find failed: "
-               << gnome_keyring_result_to_message(result);
+               << libgnome_keyring_loader_.gnome_keyring_result_to_message(
+                   result);
     return false;
   }
   // Successful read of actual data. Try migration if necessary.
   if (!migrate_tried_)
     MigrateToProfileSpecificLogins();
   return true;
 }
 
 bool NativeBackendGnome::GetLoginsCreatedBetween(const base::Time& get_begin,
                                                  const base::Time& get_end,
@@ skipping 26 matching lines @@
 bool NativeBackendGnome::GetBlacklistLogins(PasswordFormList* forms) {
   return GetLoginsList(forms, false);
 }
 
 bool NativeBackendGnome::GetLoginsList(PasswordFormList* forms,
                                        bool autofillable) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::DB));
 
   uint32_t blacklisted_by_user = !autofillable;
 
-  GKRMethod method;
+  GKRMethod method(&libgnome_keyring_loader_);
   BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
                           base::Bind(&GKRMethod::GetLoginsList,
                                      base::Unretained(&method),
                                      blacklisted_by_user, app_string_.c_str()));
   GnomeKeyringResult result = method.WaitResult(forms);
   if (result == GNOME_KEYRING_RESULT_NO_MATCH)
     return true;
   if (result != GNOME_KEYRING_RESULT_OK) {
     LOG(ERROR) << "Keyring find failed: "
-               << gnome_keyring_result_to_message(result);
+               << libgnome_keyring_loader_.gnome_keyring_result_to_message(
+                   result);
     return false;
   }
   // Successful read of actual data. Try migration if necessary.
   if (!migrate_tried_)
     MigrateToProfileSpecificLogins();
   return true;
 }
 
 bool NativeBackendGnome::GetAllLogins(PasswordFormList* forms) {
-  GKRMethod method;
+  GKRMethod method(&libgnome_keyring_loader_);
   BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
                           base::Bind(&GKRMethod::GetAllLogins,
                                      base::Unretained(&method),
                                      app_string_.c_str()));
   GnomeKeyringResult result = method.WaitResult(forms);
   if (result == GNOME_KEYRING_RESULT_NO_MATCH)
     return true;
   if (result != GNOME_KEYRING_RESULT_OK) {
     LOG(ERROR) << "Keyring find failed: "
-               << gnome_keyring_result_to_message(result);
+               << libgnome_keyring_loader_.gnome_keyring_result_to_message(
+                   result);
     return false;
   }
   // Successful read of actual data. Try migration if necessary.
   if (!migrate_tried_)
     MigrateToProfileSpecificLogins();
   return true;
 }
 
 std::string NativeBackendGnome::GetProfileSpecificAppString() const {
   // Originally, the application string was always just "chrome" and used only
@@ skipping 35 matching lines @@
     // Each other profile must be able to migrate the shared data as well,
     // so we must leave it alone. After a few releases, we'll add code to
     // delete them, and eventually remove this migration code.
     // TODO(mdm): follow through with the plan above.
     PasswordStoreX::SetPasswordsUseLocalProfileId(prefs_);
   } else {
     // We failed to migrate for some reason. Use the old app string.
     app_string_ = kGnomeKeyringAppString;
   }
 }