How the encryption happens?

[Shruthi125]

When a database is given, that is not getting encrypted but simply copies. How to resolve that and how does the encryption happen?

[davidmartos96]

What do you mean by "simply copies"?
In order to encrypt you need to provide the password parameter to openDatabase. An empty password would work like regular SQLite.

[Shruthi125]

After giving the password also its not working. And is there any database named sqlite_master in this?

[davidmartos96]

Not a database named sqlite_master, but a table. It exists in all sqlite databases.
Doing SELECT * FROM sqlite_master should work after the database is opened.

What platform are you using? Android, iOS,...
Make sure to delete the database/reinstall the app after changing the password parameter, otherwise it will try to use a different password to an already created database

[Shruthi125]

currently using Android , on debugging this is the exception occured : Exception has occurred.
SqfliteDatabaseException (DatabaseException(SQL logic error: , while compiling: select count(*) from sqlite_master;))

[davidmartos96]

Could you provide the full error stacktrace?

Are you trying to open an already encrypted database from assets? Or is the database created from scratch in the device?

[Shruthi125]

I have created a db with data but not encrypted. I want that to be encrypted and then open.

D/Sqflite (32028): Opening db in /data/user/0/com.davidmartos96.example/databases/asset_example.db with PRAGMA cipher_migrate
I/flutter (32028): DatabaseException(SQL logic error: , while compiling: select count(*) from sqlite_master;)
I/flutter (32028): #0 SqfliteSqlCipherDatabaseFactoryImpl.wrapDatabaseException (package:sqflite_sqlcipher/src/factory_sql_cipher_impl.dart:44:9)
I/flutter (32028):
I/flutter (32028): #1 SqfliteDatabaseMixin.openDatabase (package:sqflite_common/src/database_mixin.dart:777:9)
I/flutter (32028):
I/flutter (32028): #2 SqfliteDatabaseMixin.doOpen (package:sqflite_common/src/database_mixin.dart:879:22)
I/flutter (32028):
I/flutter (32028): #3 SqfliteDatabaseOpenHelper.openDatabase (package:sqflite_common/src/database.dart:46:7)
I/flutter (32028):
I/flutter (32028): #4 SqfliteDatabaseFactoryMixin.openDatabase. (package:sqflite_common/src/factory_mixin.dart:110:18)
I/flutter (32028):
I/flutter (32028): #5 ReentrantLock.synchronized. (package:synchronized/src/reentrant_lock.dart:37:18)
I/flutter (32028):
I/flutter (32028): #6 BasicLock.synchronized (package:synchronized/src/basic_lock.dart:33:16)
I/flutter (32028):
I/flutter (32028): #7 new SqlCipherTestPage. (package:sqflite_sqlcipher_example/sqlcipher_test_page.dart:89:

[davidmartos96]

@Shruthi125 That stacktrace comes from the example project. Did you change the database from the example?

I think it would be better if you can share a sample repo with what you are doing. Otherwise it is very hard to tell what's going on.

[Shruthi125]

test('Open asset database', () async {
var databasesPath = await getDatabasesPath(); //gets the path to the databases directory n assigns to var

  var path = join(databasesPath, 'asset_example.db');//constructs a path var by joining the 'databasespath' var n the filename
  // delete existing if any in the path to ensure a clean state before copying the asset database.

  await deleteDatabase(path);
  // Make sure the parent directory exists
  try {
    //Checks if the parent directory of the path exists and creates it if it doesn't. 
    await Directory(dirname(path)).create(recursive: true);
  } catch (_) {}

  // Copy filename from asset directory from 'rootBundle' object. rootBundle provides access to the asset files in flutter

       ****//I changed the db name just here and have added that to the dependency too**** 
        var data =
      await rootBundle.load(join('assets', 'Sample1.db'));    
  // Converts the loaded asset file's data into a list of integers (List<int>). This represents the binary data of the database file.    
  List<int> bytes =
      data.buffer.asUint8List(data.offsetInBytes, data.lengthInBytes);
  await File(path).writeAsBytes(bytes, flush: true);

  // open the copied database providing path n password for decryption if the database is encrypted with SQLCipher.
  var db = await openDatabase(path,password: '1234');

  /*resulting records are stored in a list of maps (List<Map<String, dynamic>>), where each map represents a record with
  column names as keys and corresponding values.*/
  List<Map<String, dynamic>> list = await db.rawQuery('SELECT * FROM state');
  print('list $list'); 
  //validation step
  expect(list.first['state_name'], 'JAMMU'); //assert the value to be the string 'simple value'
  await db.close();
});

[davidmartos96]

What that code does is open an already encrypted database with the password 1234. If you are trying to open a database without password or without a different password it will not work.

[Shruthi125]

Ok. Thank you. So I have a database with tables and related content in it. And I want to encrypt the data in that database. Please let me know how do I do that using the code

[davidmartos96]

@Shruthi125 In that case you need to use SQLCipher CLI in a desktop environment to encrypt it, then use it as an asset in the Flutter app.
Refer to this for a sample script: #20 (comment)

[Shruthi125]

Ok. Thankyou. I am using vscode in Windows desktop. So any further requirements?

[davidmartos96]

Ok. Thankyou. I am using vscode in Windows desktop. So any further requirements?

You need to install/build SQLCipher for Windows so that from the command line you can run sqlcipher.
You can then adapt the script I shared which uses bash to a bat file to run it on Windows.

[Shruthi125]

I hope this is the script.

#!/bin/bash
if [ -z "$1" ]
then
echo "No argument supplied"
exit
fi

echo "Encrypting $1"
#rm my_app_database.db
echo "ATTACH DATABASE 'encrypted.db' AS encrypted KEY '123456ABC'; SELECT sqlcipher_export('encrypted'); DETACH DATABASE encrypted;" | sqlite3 $1

echo
echo "Copying to Flutter project"
rm C:/app_mobile/assets/databases/my_app_database.db

cp encrypted.db C:/app_mobile/assets/databases/my_app_database.db
rm my_app_database.db

echo "Done."

[davidmartos96]

@Shruthi125 Yes, that's the one.

[Shruthi125]

I followed this video https://www.youtube.com/watch?v=SFHGeetZ0po and did accordingly, but the sqlite3.exe file dint generate.
Please let me know the reason for that.

[davidmartos96]

@Shruthi125 I'm sorry but I wouldn't be able to help you with that. I have experience building SQLCipher in a Linux machine, not Windows.

[Shruthi125]

Ok. Thank you

[davidmartos96]

Closing as this doesn't appear to be a problem with sqflite_sqlcipher itself