Encrypt in php and decrypt in Dart(flutter)

Question

Does anyone have an idea about encrypting response from my php api and decrypting data in local using dart. I'm using flutter for my mobile application.

Thank You!

Answer 1

You can use AES encrypt/decrypt that supported on both sides.

flutter_string_encryption

PHP

Answer 2

You can use Cipher2 library for cryptography in flutter with the help of library you can encrypt and decrypt string with "aes-128-cbc" method

    //Make sure you import the library, stringEncryption is a user define function you can define your own
    stringEncryption() async { //call this method 
    String plainText ='String to encrypt';
    String key = '1245714587458745'; //combination of 16 character
    String iv = 'e16ce913a20dadb8'; ////combination of 16 character
    String encryptedString =
    await Cipher2.encryptAesCbc128Padding7(plainText, key, iv);
    print("key:$key");
    print("iv:$iv");
    print("String:$encryptedString");

    //for decrypt use decrypt function 
    decryptedString = await Cipher2.decryptAesCbc128Padding7(encryptedString, key, iv);
    //parameters: encryptedString,sameKey,SameIv
    }

    //To decrypt in PHP
    $method = 'aes-128-cbc';
    $decryptedString = openssl_decrypt("encryptedString", $method, "SameKeyUsedInFlutter", 0, "SameIvUsedInFlutter");

    //To encrypt in PHP
    $encryptedString = openssl_encrypt("Text to encrypt", $method, "SameKeyUsedInFlutter", 0, "SameIvUsedInFlutter");
    //Key and IV must need to match

Answer 3

Here is a method for encrypting/decrypting in both Flutter and php using AES-256-CBC algorithm.

Flutter:

Include the package https://pub.dev/packages/encrypt

import 'dart:convert';

import 'package:encrypt/encrypt.dart';
import 'package:crypto/crypto.dart';

class Encryption {
  static final Encryption instance = Encryption._();
  
  late IV _iv;
  late Encrypter _encrypter;

  Encryption._() {
    const mykey = 'ThisIsASecuredKey';
    const myiv = 'ThisIsASecuredBlock';
    final keyUtf8 = utf8.encode(mykey);
    final ivUtf8 = utf8.encode(myiv);
    final key = sha256.convert(keyUtf8).toString().substring(0, 32);
    final iv = sha256.convert(ivUtf8).toString().substring(0, 16);
    _iv = IV.fromUtf8(iv);

    _encrypter = Encrypter(AES(Key.fromUtf8(key), mode: AESMode.cbc));
  }

  String encrypt(String value) {
    return _encrypter.encrypt(value, iv: _iv).base64;
  }

  String decrypt(String base64value) {
    final encrypted = Encrypted.fromBase64(base64value);
    return _encrypter.decrypt(encrypted, iv: _iv);
  }
}

PHP:

<?php

class Encryption
{
    private string $encryptMethod = 'AES-256-CBC';
    private string $key;
    private string $iv;

    public function __construct()
    {
        $mykey = 'ThisIsASecuredKey';
        $myiv = 'ThisIsASecuredBlock';
        $this->key = substr(hash('sha256', $mykey), 0, 32);
        $this->iv = substr(hash('sha256', $myiv), 0, 16);
    }

    public function encrypt(string $value): string
    {
        return openssl_encrypt($value, $this->encryptMethod, $this->key, 0, $this->iv);
    }

    public function decrypt(string $base64Value): string
    {
        return openssl_decrypt($base64Value, $this->encryptMethod, $this->key, 0, $this->iv);
    }
}

Answer 4

function CryptoJSAesDecrypt(passphrase,encrypted_json_string){

var obj_json = JSON.parse(encrypted_json_string);

var encrypted = obj_json.ciphertext;
var salt = CryptoJS.enc.Hex.parse(obj_json.salt);
var iv = CryptoJS.enc.Hex.parse(obj_json.iv);   

var key = CryptoJS.PBKDF2(passphrase, salt, { hasher: CryptoJS.algo.SHA512, keySize: 64/8, iterations: 999});


var decrypted = CryptoJS.AES.decrypt(encrypted, key, { iv: iv});

return decrypted.toString(CryptoJS.enc.Utf8);

} i want to covert php func crypto to flutter