Dooble
A Scientific Web Browser
Document Version 2024.01.18
Dooble is an elegant, portable, and zero-dependency Web browser. The program should be functional on any operating system where the newest Qt is supported.
The source is readily available at https://github.com/textbrowser/dooble.
The AES implementation is derived from the guidelines provided by http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.197.pdf. The implementation is independent of architecture.
Dooble supports the accepting and blocking of specific domains. The Accepted / Blocked Domains window allows for the defining of domains which are to be accepted or blocked. Domains are stored in the SQLite database dooble_accepted_or_blocked_domains.db. An operating mode may also be prepared within this window. Supported operating modes are defined below.
Only the specified domains may be accessed either directly or indirectly.
The specified domains are blocked. While in this mode, Dooble will prevent direct and indirect access to the listed domains.
The section contains links of third-party cookies which were rejected by Dooble.
Note: Defined domains also reside in a session container which is optimized for rapid (amortized O(1)) discovery. The special container contains all of the defined domains.
Note: The bundled Data directory contains the file dooble_accepted_or_blocked_domains.txt. An import feature is included in the Accepted / Blocked Domains window. An import will enable (Blocked or Accepted) existing domains.
The address widget contains the current page’s URL. The present URL may be inserted in the Favorites container by pressing the favorites (star) tool button.
The current site’s cookies may be accessed via a context menu. The context menu also allows for the removal of the current site’s non-private certificate exception if a certificate exception has been previously accepted.
Note: All address widgets share a common history container. The container is optimized for rapid (amortized O(1)) discovery of history items and is required for displaying previously-accessed URLs in address widgets.
Note: Certificate exceptions are not available for private URLs. That is, if a certificate exception is accepted from a private window, the exception is only available within that window. Other non-private and private Dooble windows will not have insight into the accepted certificate exception.
Note: Dooble applies the Levenshtein Distance algorithm during the history-discovery process.
Note: Private windows record visited links in the internal history containers.
A Dooble session may be locked via a tab’s context menu’s Lock Application action. The Lock Application action is disabled if credentials have not been prepared.
Web sites may raise SSL/TLS certificate errors. Some of these certificate errors may be overridden.
Once overridden, the Web site and the certificate error are recorded in the SQLite database dooble_certificate_exceptions.db unless the parent window is a private window. For private windows, certificate exceptions exist only within such windows.
Overridden non-private sites are presented in the Certificate Exceptions window. Within this window, exceptions may be revoked.
Note: Certificate errors may be raised by third-party requests.
Note: Dooble allows for a single certificate exception to be defined for a given URL. Future revisions may allow for multiple exceptions.
Note: Private windows will also interrogate permanent certificate exceptions. If a permanent certificate exception is discovered for the given private URL, the particular Web site will be loaded by the private page.
The Clear Items modal dialog may be used to remove an assortment of content.
The command-line option --load-url is supported by Dooble. Multiple instances are allowed.
The command-line option --private is supported by Dooble. If provided, the first Dooble window will be a private window.
The command-line option --test-aes may be used to test the AES implementation. See also –test-aes-performance.
The command-line option --test-threefish may be used to test the Threefish implementation. See also –test-threefish-performance.
Windows users, please create a shortcut to the Dooble.exe file and add the --private option to the Target field.
Other command-line options are available via WebEngine. Please read https://peter.sh/experiments/chromium-command-line-switches/. The option disable-reading-from-canvas may be of interest.
The Cookies window depicts Dooble’s current cookies. The SQLite database dooble_cookies.db contains cookie data.
If set, only the specified domain's cookies are displayed.
If enabled, unchecked domains will be purged every 15 seconds. Purging occurs on the main thread.
The Debian package may be GPG-signed. This section describes the process of verifying the digital signature.
First, create a special directory.
> mkdir 66E6A4C70DA51DCD
Next, install debsig-verify via aptitude.
> sudo apt install debsig-verify
Then, copy the bundled file Documentation/dooble.pol to 66E6A4C70DA51DCD.
> cp Documentation/dooble.pol 66E6A4C70DA51DCD
Import the bundled public key Documentation/dooble.asc.
> gpg --no-default-keyring --keyring 66E6A4C70DA51DCD/debsig.gpg --import Documentation/dooble.asc
Finally, verify the Debian package.
> debsig-verify --keyrings-dir . --policies-dir . ./Dooble-2019.01.15_amd64.deb
Results should be similar to the following.
debsig: Verified package from 'Dooble' (Text Browser)
Dooble supports the downloading of data. Active and inactive downloads are depicted in the Downloads window. Active downloads may be canceled. Files associated with canceled downloads are discarded. Dooble provides a mechanism for restarting a canceled or interrupted download if the application is generated using Qt 5.10.x and newer. Downloads data are stored in the SQLite database dooble_downloads.db.
Favorites are replacements of bookmarks. Included in the Favorites non-modal dialog are various sort options. Favorites, along with history items, are stored in the SQLite database dooble_history.db.
Dooble offers a traditional menu bar. The menu bar’s visibility may be configured via the Display panel in the Settings window. If the menu bar is permanently hidden, its visibility may be modified via the F10 key. Some menu options include mnemonics and shortcuts.
The File menu includes several basic functions.
If permanent credentials are defined, this option is enabled. An authentication dialog is displayed if the option is selected. If credentials are correctly authenticated, global containers are populated. Please note that interface components must be populated via the main thread and this activity may burden Dooble.
Open a new private window. Please also read the Private Windows section for details on private browsing.
A new tab is appended to the end of the tab widget.
Open a new window.
Close the current tab. If the current tab is the only Dooble tab and active downloads exist, a confirmation prompt is displayed.
Place focus on the URL widget.
Save the current page. The action invokes a download request. A file-selection dialog is not displayed.
A modal print dialog is displayed.
Display a preview of the current page.
Exit Dooble. A confirmation prompt is displayed if active downloads exist.
Display an instance of the modal Clear Items dialog.
Remove contents from the local Visited Links file.
Enables the Find panel.
Display the Settings window.
Vacuum local SQLite databases.
Display the Accepted / Blocked Domains window.
Display the Certificate Exceptions window.
Display a sub-menu of available charts. Charts are disabled if Dooble was built without the QtCharts module.
Display the global Cookies window. If the window is a private window, the private window's Cookies window is displayed.
Display the Downloads window.
Display the Favorites non-modal dialog.
Display a digital clock dialog.
Display the History window.
Also available off of the address widget. Allows custom style sheets to be injected into individual pages.
Display the Search Engines window.
Disable or enable full-screen mode.
Hide or show the status bar.
Clear the history.
Show the History window.
Display the non-modal About dialog.
Display this document in a Dooble tab.
Display Dooble’s release notes in a separate tab.
The History window is a general-purpose container depicting Dooble’s browsing history. A simple search is included. Selected items may be removed via a context menu. The SQLite database dooble_history.db contains history data, along with favorites data.
Note: Purged items are not automatically removed from the History window during a session. Subsequent sessions will represent the most current contents of dooble_history.db.
The environment variable DOOBLE_HOME is supported. If correctly set, Dooble files will reside in DOOBLE_HOME. The variable may be used to create multiple profiles.
MacOS
Dooble files reside in the user’s .dooble directory.
Unix
If XDG_CONFIG_HOME or XDG_DATA_HOME is defined, the .dooble directory resides within one of the directories. Otherwise, Dooble files reside in the user’s .dooble directory.
Windows
Dooble files reside in the current directory’s .dooble directory if the directory is readable and writable. Otherwise, the .dooble directory resides in QDir::home().
•Accepted / Blocked domains are stored in a container that’s designed for rapid (amortized O(1)) discovery. The container is populated during the initialization of Dooble.
•Authentication may be interrupted.
•Constant byte-by-byte comparisons are implemented wherever cryptographic digests are involved.
•Cryptographic keys are zeroed on destruction. Sensitive fields are cleared after use. Please note that these processes do not guarantee that sensitive data are destroyed effectively.
•Dooble attempts to lock secret keys into RAM, if mman is available.
•Dooble populates icons of table items only when required. The software inspects respective views and determines the entries which require icons.
•History items are safely purged within a dedicated thread.
•Initial gathering of History data is performed by a thread.
•Processing large quantities of icon data will certainly burden most software applications. Dooble provides an innovative solution. Address widgets, the Favorites window, the History window, and the Search Engines window implement an intelligent algorithm which causes Dooble to load only the icon data of visible items. Once loaded, the icon data are cached. Also included are SQLite database indexes. This innovative solution produces exceptionally-smooth rendering of important data.
•Some SQLite database writes occur without synchronization. Future releases will introduce synchronization.
•The AES and Threefish implementations are not designed to be thread-safe.
•The process of preparing credentials may be interrupted.
When browsing in private windows, Dooble does not save the following data:
•Certificate Exceptions
•Cookies
•Favicons
•History
•Temporary Files
•Visited Links
While in private windows, Dooble does save:
•Downloads
•Favorites
This section describes some of the interesting areas of the Settings window. Settings values are stored in the SQLite database dooble_settings.db.
Some support windows may be pinned. Pinning is the process of embedding support windows within a Dooble window.
A dedicated thread determines if browsing history has expired. The thread is also responsible for removing expired history data. The thread is safely canceled upon termination of Dooble.
Dooble provides a process of storing authentically-encrypted data in various databases. This process is completely optional. Three separate modes are included:
This is the default mode. In this mode, Dooble stores data in clear text.
Dooble shall permanently store data in authentically-encrypted containers using credentials generated via the provided password.
Dooble shall store private data in authentically-encrypted containers using session credentials. The data will not be available in future sessions.
Additional specifics are listed bellow.
CBC is the preferred cipher mode of operation.
SHA3-512 is the favored hash algorithm.
The password must contain at least 1 character.
The process may be interrupted if desired.
The pseudo-random password salt is composed of 64 bytes.
Set the environment variable TZ to UTC.
Required for HTML5 storage.
The user agent is sometimes used for content negotiation between the Dooble client and a server. The initial value is system-dependent. To reset, please clear the field and press the Apply button. Please reset the field whenever new Qt products are provided.
Limits WebRTC to public IP addresses. If disabled, remote hosts may be able to detect local IP addresses.
Per Qt’s documentation, XSS Auditing monitors load requests for cross-site scripting attempts. Suspicious scripts are blocked.
Note: Dooble does not remove the local WebEnginePersistentStorage directory during a reset. Please remove this directory after a reset completes.
Dooble requires data streams of random data for an assortment of cryptographic algorithms. This section briefly describes the sources of these data streams for various operating systems.
See QRandomGenerator.
See QRandomGenerator.
See QRandomGenerator.
See QRandomGenerator.
Dooble supports the FILE, FTP, GOPHER, HTTP(S), and JAR schemes.
The Threefish implementation is derived from the guidelines provided by http://www.skein-hash.info/sites/default/files/skein1.1.pdf. The implementation is independent of architecture.
Translations are incomplete. Translating Dooble is quite simple. Please download and install Qt from https://download.qt.io, download Dooble’s source, and become an expert in Qt’s Linguist. Linguist documentation exists at https://doc.qt.io/qt-5/qtlinguist-index.html.
Some pages may submit requests for accessing local devices. When a feature request is received by Dooble, a notification is displayed. A request may be accepted or denied. The URL and the policy are recorded after a transaction completes. Existing entries may be reviewed via the Web panel of the Settings window.
Please note that a notification is displayed only for the first received request for a given page during a page load. That is, received requests are not queued. If a request is received while a request is pending, the received request is denied and an entry is added to the Features Permissions panel of the Web section in the Settings window.
As of October 4, 2018, Qt 5.11.2 requires Windows Studio 2017. Please download the Community edition from https://visualstudio.microsoft.com/downloads/.