pinentrygtk3

pinentrygtk3 is a GTK+3-based pin entry dialog used by the GnuPG ecosystem to securely collect passphrases. It is part of the pinentry family, which provides graphical input for the pinentry protocol used by gpg-agent. When a passphrase is needed for signing, decrypting, or authenticating, gpg-agent invokes pinentrygtk3 to obtain the input from the user.

The user interface presents a simple dialog with a prompt, a password field, and action buttons. It uses the GTK+3 toolkit to integrate with modern desktop environments and supports multiple languages through gettext. The dialog is designed to avoid displaying the entered characters and to minimize the risk of credential leakage by handling input within the pinentry process and returning only the passphrase to the agent.

Installation and configuration: On most Linux distributions, pinentrygtk3 is provided as a separate package. To use it by default, configure gpg-agent to set the pinentry-program to pinentry-gtk3 in its configuration file (typically gpg-agent.conf) and restart the agent. The pinentry process is launched on demand and communicates with gpg-agent via the pinentry protocol.

Relationship to other pinentry frontends: pinentrygtk3 is one of several graphical frontends, alongside pinentry-gtk2 and pinentry-qt. It targets GTK+3 environments and is commonly preferred on systems using GTK3. The pinentry suite also includes non-graphical variants, such as pinentry-curses, providing options for environments where a graphical dialog is unavailable.