[management] Add GCM encryption and migrate legacy encrypted events (#2569)

* Add AES-GCM encryption

Signed-off-by: bcmmbaga <bethuelmbaga12@gmail.com>

* migrate legacy encrypted data to AES-GCM encryption

Signed-off-by: bcmmbaga <bethuelmbaga12@gmail.com>

* Refactor and use transaction when migrating data

Signed-off-by: bcmmbaga <bethuelmbaga12@gmail.com>

* Add events migration tests

Signed-off-by: bcmmbaga <bethuelmbaga12@gmail.com>

* fix lint

Signed-off-by: bcmmbaga <bethuelmbaga12@gmail.com>

* skip migrating record on error

Signed-off-by: bcmmbaga <bethuelmbaga12@gmail.com>

* Preallocate capacity for nonce to avoid allocations in Seal

Signed-off-by: bcmmbaga <bethuelmbaga12@gmail.com>

---------

Signed-off-by: bcmmbaga <bethuelmbaga12@gmail.com>

management/server/activity/sqlite/migration_test.go

@@ -0,0 +1,84 @@
+package sqlite
+
+import (
+	"context"
+	"database/sql"
+	"path/filepath"
+	"testing"
+	"time"
+
+	_ "github.com/mattn/go-sqlite3"
+	"github.com/netbirdio/netbird/management/server/activity"
+
+	"github.com/stretchr/testify/require"
+)
+
+func setupDatabase(t *testing.T) *sql.DB {
+	t.Helper()
+
+	dbFile := filepath.Join(t.TempDir(), eventSinkDB)
+	db, err := sql.Open("sqlite3", dbFile)
+	require.NoError(t, err, "Failed to open database")
+
+	t.Cleanup(func() {
+		_ = db.Close()
+	})
+
+	_, err = db.Exec(createTableQuery)
+	require.NoError(t, err, "Failed to create events table")
+
+	_, err = db.Exec(`CREATE TABLE deleted_users (id TEXT NOT NULL, email TEXT NOT NULL, name TEXT);`)
+	require.NoError(t, err, "Failed to create deleted_users table")
+
+	return db
+}
+
+func TestMigrate(t *testing.T) {
+	db := setupDatabase(t)
+
+	key, err := GenerateKey()
+	require.NoError(t, err, "Failed to generate key")
+
+	crypt, err := NewFieldEncrypt(key)
+	require.NoError(t, err, "Failed to initialize FieldEncrypt")
+
+	legacyEmail := crypt.LegacyEncrypt("testaccount@test.com")
+	legacyName := crypt.LegacyEncrypt("Test Account")
+
+	_, err = db.Exec(`INSERT INTO events(activity, timestamp, initiator_id, target_id, account_id, meta) VALUES(?, ?, ?, ?, ?, ?)`,
+		activity.UserDeleted, time.Now(), "initiatorID", "targetID", "accountID", "")
+	require.NoError(t, err, "Failed to insert event")
+
+	_, err = db.Exec(`INSERT INTO deleted_users(id, email, name) VALUES(?, ?, ?)`, "targetID", legacyEmail, legacyName)
+	require.NoError(t, err, "Failed to insert legacy encrypted data")
+
+	colExists, err := checkColumnExists(db, "deleted_users", "enc_algo")
+	require.NoError(t, err, "Failed to check if enc_algo column exists")
+	require.False(t, colExists, "enc_algo column should not exist before migration")
+
+	err = migrate(context.Background(), crypt, db)
+	require.NoError(t, err, "Migration failed")
+
+	colExists, err = checkColumnExists(db, "deleted_users", "enc_algo")
+	require.NoError(t, err, "Failed to check if enc_algo column exists after migration")
+	require.True(t, colExists, "enc_algo column should exist after migration")
+
+	var encAlgo string
+	err = db.QueryRow(`SELECT enc_algo FROM deleted_users LIMIT 1`, "").Scan(&encAlgo)
+	require.NoError(t, err, "Failed to select updated data")
+	require.Equal(t, gcmEncAlgo, encAlgo, "enc_algo should be set to 'GCM' after migration")
+
+	store, err := createStore(crypt, db)
+	require.NoError(t, err, "Failed to create store")
+
+	events, err := store.Get(context.Background(), "accountID", 0, 1, false)
+	require.NoError(t, err, "Failed to get events")
+
+	require.Len(t, events, 1, "Should have one event")
+	require.Equal(t, activity.UserDeleted, events[0].Activity, "activity should match")
+	require.Equal(t, "initiatorID", events[0].InitiatorID, "initiator id should match")
+	require.Equal(t, "targetID", events[0].TargetID, "target id should match")
+	require.Equal(t, "accountID", events[0].AccountID, "account id should match")
+	require.Equal(t, "testaccount@test.com", events[0].Meta["email"], "email should match")
+	require.Equal(t, "Test Account", events[0].Meta["username"], "username should match")
+}