from Crypto.Util.Padding import pad
from Crypto.Cipher import AES
import base64
 
class PrpCrypt(object):
 
    def __init__(self):
        self.unpad = lambda date: date[0:-ord(date[-1])]
 
    def aes_cipher(self, key, aes_str):
        aes = AES.new(key.encode('utf-8'), AES.MODE_ECB)
        pad_pkcs7 = pad(aes_str.encode('utf-8'), AES.block_size, style='pkcs7') 
        encrypt_aes = aes.encrypt(pad_pkcs7)
        encrypted_text = str(base64.encodebytes(encrypt_aes), encoding='utf-8') 
        encrypted_text_str = encrypted_text.replace("\n", "")
 
        return encrypted_text_str
 
    def decrypt(self, key, decrData):
        res = base64.decodebytes(decrData.encode("utf8"))
        aes = AES.new(key.encode('utf-8'), AES.MODE_ECB)
        msg = aes.decrypt(res).decode("utf8")
        return self.unpad(msg)
 
 
if __name__ == '__main__':
    # replace with your callback key
    key = "d655c33205363f5450427e6b6193e466"

    # callback data to be decrypted
    paymentResult = "mX2Ku+jslxIXDSQMxl3wzDclIiKilKlakN2149ijiV467m3lgyQTHuUlobdKDUrfxa5xlMg5HLj9MuO0WWssf+EjcRnPI8LMxU7LnM8lDYO52QeuU1bZ/0WV95jzJ1jOt6AJXNiSl+wu6wy6sQioCjVyyRXIpSug/4pokaXkIdQCpZo/YKa5QpVtSf1DucnCG/ESsxTw1sJQ39Pox8tdbcSvTPZrdFzcAyi/C8JFVtavTaUS8X1QndfKQphquZVhfKhVBA8etZaMwsoclfB8/e8mCSMUn+2s7/LYf9i9QHqlVdoS2ssTqJT+Rcfs9/Wa"
        
    result = PrpCrypt().decrypt(key,paymentResult)
    print(result)



                                    

                                        
// decrypt callback data
       
       $paymentResult = $request->paymentResult;
       $checkSum = $request->checksum;
       $callbackKey =  "7f4917e39f698ac433ac1d207e139adc";
       $decrypted = openssl_decrypt($paymentResult,"AES-256-ECB", $callbackKey);

               // check callback data with hash value
       if(hash("sha256", $decrypted) !== $checkSum){
           return "incorrect Singanature.";
       } elseif (hash("sha256", $decrypted) == $checkSum) {
           // get callback data
               $decryptedValues = json_decode($decrypted, true);
           $transactionStatus = $decryptedValues["transactionStatus"];
           $merchantOrderId = $decryptedValues["merchantOrderId"];
           $totalAmount = $decryptedValues["totalAmount"];
           $methodName = $decryptedValues["methodName"];
           $providerName = $decryptedValues["providerName"];
           $transactionId = $decryptedValues["transactionId"];
           $customerName = $decryptedValues["customerName"];
         
           // do callback success function here
       }


                                    

import * as aesEcb from 'aes-ecb';

const SECRET_KEY = 'd655c33205363f5450427e6b6193e466';
const cipherText ="5zDOSGSI/YE7wsmX/IlBZb6iH0NpwgRuUL13RY9sEKIvo8oebHCh1FKZ0MKTkvlKPQ6Cn2qYg7UDQssBuMbkVAGWcVPK0WvvrrACrx480jdydrNUcsqX4vsaqHuRlCQa/7Qfur+W6WNKO4exvOvN25FtE8hDB7ENu37r54wUlGC21bojhq9M15/Ql5P9+w1x/+Ep13nmyptGOHfI4a4V3D57v0HQ8KqUnOy5P6E4FYOSeOVeVuCJ516RK94OIVAUB3F9jqy4NLm9jqc243pWOR9fwGJK5YplMbOuQFEZKt0=";

const resultObj = aesEcb.decrypt(SECRET_KEY, cipherText);
console.log(resultObj);

import { sha256 } from "js-sha256";
let sign = sha256(resultObj);
console.log(sign);

* This sign value and the checksum value(from the URL) must be same, if not we have to assume incorrect signature and return error *


                                    

                                        
val paymentDecrypted = decryptWithAES(callbackKey, paymentResult)

fun decryptWithAES(key: String, strToDecrypt: String?): String? {
        Security.addProvider(BouncyCastleProvider())
        val keyBytes: ByteArray

        try {
            keyBytes = key.toByteArray(charset("UTF8"))
            val skey = SecretKeySpec(keyBytes, "AES")
            val input = org.bouncycastle.util.encoders.Base64
                .decode(strToDecrypt?.trim { it <= ' ' }?.toByteArray(charset("UTF8")))

            synchronized(Cipher::class.java) {
                val cipher = Cipher.getInstance("AES/ECB/PKCS7Padding")
                cipher.init(Cipher.DECRYPT_MODE, skey)

                val plainText = ByteArray(cipher.getOutputSize(input.size))
                var ptLength = cipher.update(input, 0, input.size, plainText, 0)
                ptLength += cipher.doFinal(plainText, ptLength)
                val decryptedString = String(plainText)
                return decryptedString.trim { it <= ' ' }
            }
        } catch (uee: UnsupportedEncodingException) {
            uee.printStackTrace()
        } catch (ibse: IllegalBlockSizeException) {
            ibse.printStackTrace()
        } catch (bpe: BadPaddingException) {
            bpe.printStackTrace()
        } catch (ike: InvalidKeyException) {
            ike.printStackTrace()
        } catch (nspe: NoSuchPaddingException) {
            nspe.printStackTrace()
        } catch (nsae: NoSuchAlgorithmException) {
            nsae.printStackTrace()
        } catch (e: ShortBufferException) {
            e.printStackTrace()
        }

        return null
    }


                                    

    $servername = "localhost";
    $username = "username";
    $password = "password";
    $dbname = "dbname";

    $conn = new mysqli($servername, $username, $password, $dbname);
    // Check connection

    if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
    }

    $result = file_get_contents("php://input");

    $decodeValue = json_decode($result, true);

    $paymentResult = $decodeValue['paymentResult'];
    $checkSum = $decodeValue['checksum'];

    $secrectKey = "d655c33205363f5450427e6b6193e466";
    $decrypted = openssl_decrypt($paymentResult,"AES-256-ECB", $secrectKey);


    if(hash("sha256", $decrypted) !== $checkSum){

    echo "incorrect Singanature.";

    } elseif (hash("sha256", $decrypted) == $checkSum) {

    $decryptedValues = json_decode($decrypted, true);

    $transactionStatus = $decryptedValues["transactionStatus"];

    $merchantOrderId = $decryptedValues["merchantOrderId"];

    $totalAmount = $decryptedValues["totalAmount"];

    $methodName = $decryptedValues["methodName"];

    $providerName = $decryptedValues["providerName"];

    $transactionId = $decryptedValues["transactionId"];

    $customerName = $decryptedValues["customerName"];

    $date = date("Y-m-d H:i:s");

    if ( $transactionStatus == "SUCCESS" ) {
    $success = "display your success message to customer and save the transaction to db.
    and do some success function for your app";
    $sql = "INSERT INTO callback_data (totalAmount, transactionStatus, methodName,
    providerName, merchantOrderId, transactionId, customerName, created_at, updated_at )
    VALUES ('$totalAmount', '$transactionStatus', '$methodName', '$providerName',
    '$merchantOrderId', '$transactionId', '$customerName', '$date', '$date' )";

    if ($conn->query($sql) === TRUE) {
    echo "New record created successfully";
    } else {
    echo "Error: " . $sql . "<br>" . $conn->error;
    }
    } else {
    $error = "display error message and save the transaction to db";
    }

    $callBackResponse = array(
    'transactionStatus' => $transactionStatus,
    'merchantOrderId' => $merchantOrderId,
    'totalAmount' => $totalAmount,
    'methodName' => $methodName,
    'providerName' => $providerName,
    'transactionId' => $transactionId,
    'customerName' => $customerName,
    );


    header('Content-Type: application/json');
    echo json_encode(array("data"=>$callBackResponse));
    }