Authenticated encryption for enterprise secrets (#1078)

app/MindWork AI Studio/Settings/SettingsManager.cs

@@ -186,6 +186,11 @@ public sealed class SettingsManager
 
             this.logger.LogInformation("No valid current-version settings backup was found. Migrating the settings file.");
             settingsData = SettingsMigrations.Migrate(this.logger, settingsVersion.Version, await File.ReadAllTextAsync(settingsPath), JSON_OPTIONS);
+
+            // Compatibility shim, remove after 2027-10-31, see KeepTheLegacyEncryptionExportFormat.
+            // Settings of an older version always come from before the export format existed:
+            settingsData.App.EnterpriseEncryptionExportFormat = EnterpriseEncryptionFormat.V1;
+
             this.PrepareLoadedSettings(settingsData);
             await this.StoreSettingsSnapshot(settingsData, settingsPath);
             await this.StoreCurrentVersionBackup(settingsData);
@@ -291,7 +296,8 @@ public sealed class SettingsManager
     {
         try
         {
-            var settingsData = JsonSerializer.Deserialize<Data>(await File.ReadAllTextAsync(settingsPath), JSON_OPTIONS);
+            var settingsJson = await File.ReadAllTextAsync(settingsPath);
+            var settingsData = JsonSerializer.Deserialize<Data>(settingsJson, JSON_OPTIONS);
             if(settingsData is null)
             {
                 this.logger.LogError($"Failed to parse the {sourceDescription} '{settingsPath}'.");
@@ -304,6 +310,7 @@ public sealed class SettingsManager
                 return new(null, SettingsWriteBlockReason.CURRENT_VERSION_INVALID);
             }
 
+            KeepTheLegacyEncryptionExportFormat(settingsData, settingsJson);
             return new(settingsData, SettingsWriteBlockReason.NONE);
         }
         catch(Exception e)
@@ -313,6 +320,28 @@ public sealed class SettingsManager
         }
     }
 
+    /// <summary>
+    /// Lets an installation which existed before v26.10.1 keep exporting encrypted secrets in the
+    /// format v1, which every version of AI Studio reads.
+    /// </summary>
+    /// <remarks>
+    /// Compatibility shim, remove after 2027-10-31, see
+    /// documentation/compatibility-shims/2026-10-enterprise-encryption-export-format.md.<br/><br/>
+    /// New installations export in the authenticated format v2. An existing installation, however,
+    /// may belong to an administrator whose organization still runs an older version, which reads
+    /// v1 only. Settings written before v26.10.1 lack the export format, and nothing else tells
+    /// such an installation apart. Once the settings are stored, they hold the format, and this
+    /// changes nothing anymore.
+    /// </remarks>
+    private static void KeepTheLegacyEncryptionExportFormat(Data settingsData, string settingsJson)
+    {
+        using var settingsDocument = JsonDocument.Parse(settingsJson);
+        if(settingsDocument.RootElement.TryGetProperty(nameof(Data.App), out var appElement) && appElement.ValueKind is JsonValueKind.Object && appElement.TryGetProperty(nameof(DataApp.EnterpriseEncryptionExportFormat), out _))
+            return;
+
+        settingsData.App.EnterpriseEncryptionExportFormat = EnterpriseEncryptionFormat.V1;
+    }
+
     private void BlockSettingsWrites(SettingsWriteBlockReason reason, string message)
     {
         this.SettingsWriteBlockReason = reason;