Flutter Encryption and Decryption using flutter string encryption

Hi Guys Welcome to Proto Coders Point, In this Flutter tutorial we will check how to encrypt password in flutter using flutter string encryption.

Video Tutorial

Flutter string encryption Package Plugin

This package is very useful for string encryption, it’s a Cross platform string encryption which uses commonly best Encrytion methods like (AES/CBC/PKCS5/RandomIVs/HMAC-SHA256 Integrity Check).

Installation of Flutter Encryption package

1. Adding Dependencies in pubspec.yaml file

open your flutter project that you have created in your IDE(android-studio).

In your project structure you may see a file by name pubspec.yaml name open, in this file under dependencies add the package

dependencies:
  flutter_string_encryption: ^0.3.1   // add this line // package version may change kindly check update version on offical site

2. Importing the package

Then after you have added the required flutter encryption package now you need to import the package where you will be using it in your code to encrypt or decrypt the string or the password the user enter.

import 'package:flutter_string_encryption/flutter_string_encryption.dart';

So now the flutter encryption and decryption package is been successfully added into your flutter project, now you can use it.

So now let’s check how to encrypt a string using flutter string encryption

Usage of the library

// create a PlatformStringCryptor

In Below Snippet code we have creating an object of PlatformStringCryptor that will help use in creatng salt and to generate key.

final cryptor = new PlatformStringCryptor();

// generate a Salt string using Cryptor

final String salt = await cryptor.generateSalt();

//generate a key from password

Here password is the text that user enter in textfield

final String key = await cryptor.generateKeyFromPassword(password, salt);

Encrypt A String

final String encrypted = await cryptor.encrypt("Password that you want to encrypt", key);

Decrypt A String

try {
  final String decrypted = await cryptor.decrypt(encrypted, key);
  print(decrypted); // - A string to encrypt.
} on MacMismatchException {
  // unable to decrypt (wrong key or forged data)
}

IMPORTANT NOTE

Then key that is used to Encrypt a string should be same while you want to decrypt the encrypted string.

Implementing Flutter Encryption decryption in Flutter Project

main.dart

import 'dart:math';

import 'package:flutter/material.dart';
import 'package:flutter_string_encryption/flutter_string_encryption.dart';


void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(

        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {

  TextEditingController pass = TextEditingController();

  var key = "null";
  String encryptedS,decryptedS;

  var password = "null";

  PlatformStringCryptor cryptor;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Password Encrypt"),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Padding(
              padding: const EdgeInsets.fromLTRB(30, 0, 30, 0),
              child: TextField(
                controller: pass,
                decoration: InputDecoration(
                  hintText: 'Password',
                  hintStyle: TextStyle(color: Colors.black),
                  enabledBorder: OutlineInputBorder(
                    borderRadius: new BorderRadius.circular(10.0),
                    borderSide: BorderSide(
                        color: Colors.red
                    ),
                  ),
                  focusedBorder: OutlineInputBorder(
                      borderRadius: new BorderRadius.circular(10.0),
                      borderSide: BorderSide(
                          color: Colors.blue[400]
                      )
                  ),
                  isDense: true,                      // Added this
                  contentPadding: EdgeInsets.fromLTRB(10, 20, 10, 10),
                ),
                cursorColor: Colors.white,
              ),
            ),
            RaisedButton(
              onPressed: (){
                Encrypt();
              },
              child: Text("Encrypt"),
            ),
            RaisedButton(
              onPressed: (){
                Decrypt();
              },
              child: Text("Decrypt"),
            ),
          ],
        ),
      ),
    );
  }

// method to Encrypt String Password
  void Encrypt() async{

    cryptor = PlatformStringCryptor();
    final salt = await cryptor.generateSalt();

    password = pass.text;

    key = await cryptor.generateKeyFromPassword(password, salt);

  // here pass the password entered by user and the key
    encryptedS = await cryptor.encrypt(password, key);

    print(encryptedS);
  }


// method to decrypt String Password
  void Decrypt() async{

    try{
      //here pass encrypted string and the key to decrypt it 
      decryptedS = await cryptor.decrypt(encryptedS, key);

      print(decryptedS);
    }on MacMismatchException{

    }
  }

}

Output