Flutter : Store passwords in encrypted sqlite db

I am working on an app that can store passwords in encrypted way in an sqlite db. The idea is, user will input a 4-6 digit pin (preferably number) and the stored passwords can only be viewed after the user enters the pin. I am trying to create a way, by which the pin can be used as an encryption key.

These are the conditions that I am trying to work on;

1. Password stored in encrypted way in a sqlitedb

2. the db should secure enough that if some body dis-assembles the app,
   they shouldn't be able to crack it open (hopefully).

3. Possibly able to upload the db file to user's Apple/Google cloud as backup and later restore it.

Can you guys suggest what would be the best way to achieve these ? any package or combination of packages. Since I am trying to find out if this is indeed possible, I don't have a code yet. It's more to validate an approach with a larger community. Please don't remove this post.

I would say it is a doable task. First of all, you can use this package for working with Sqlite database (looks like it is quite popular):

https://pub.dev/packages/sqflite

Second thing is password encryption, well, if you need to be able to view the password using pin, I would recommend symmetric encryption for that. There is a lot of symmetric algorithms, that you can use to encrypt and decrypt password with single key (it can be pin):

https://cryptobook.nakov.com/symmetric-key-ciphers/popular-symmetric-algorithms

To achieve second point you probably need to generate some salt that will be kept on local device storage, so you can use it in application together with pin.

For synchronizing file with cloud you can use another packages like:

(look for Drive api) https://pub.dev/packages/googleapis

(not very popular, but probably works) https://pub.dev/packages/driven