SQLite.Encrypted Avalonia desktop journal

This sample is a cross-platform desktop notes application built with Avalonia and the published SQLite.Encrypted NuGet package. It demonstrates encrypted CRUD and search on Windows, macOS, and Linux.

Database code is isolated in Data/. It uses Microsoft.Data.Sqlite.Core for idiomatic ADO.NET connections, commands, parameters, and readers. The SQLitePCLRaw.provider.e_sqlite3 package selects the native e_sqlite3 library supplied by SQLite.Encrypted. Avalonia code stays in MainWindow.axaml and its code-behind.

Requirements

• .NET 8 SDK or later
• a SQLite.Encrypted activation key valid for the current platform and SQLite 3.54

Free fully-featured demo keys are available from sqlite.sourcegear.com.

Run

The activation key can be entered in the unlock screen. To prefill it without putting it in source code, set this environment variable:

$env:SQLITE_ENCRYPTED_ACTIVATION_KEY = '<activation key without the see- prefix>'

Then restore and run:

cd sqlite-encrypted-dotnet-avalonia-journal
dotnet restore
dotnet run

Enter a database passphrase in the unlock screen. The encrypted database is stored in the current user's local application-data folder under SQLiteEncrypted/AvaloniaJournal/journal.db. The sample does not persist the activation key or database passphrase.

Security behavior

Opening the journal performs this checked sequence:

1. Configure SQLite3Provider_e_sqlite3 before starting Avalonia.
2. Open a non-pooled Microsoft.Data.Sqlite.SqliteConnection.
3. Activate SEE with PRAGMA activate_extensions = 'see-…'.
4. Run PRAGMA key and require its first result to be ok.
5. Read sqlite_master so a wrong passphrase fails before schema creation.

An invalid activation attempt affects the process-global SEE state. The sample therefore disables another unlock attempt and tells the user to restart the application.

Publish

Publish for the intended desktop runtime so .NET selects the matching native e_sqlite3 asset:

dotnet publish -c Release -r win-x64 --self-contained false
dotnet publish -c Release -r linux-x64 --self-contained false
dotnet publish -c Release -r osx-arm64 --self-contained false