feat: added tpv app

tpv/utils.py

@@ -0,0 +1,99 @@
+import base64
+import hashlib
+import hmac
+import json
+
+import pyDes
+import re
+
+from decimal import Decimal
+from django.utils.text import gettext_lazy as _
+
+from tpv.exceptions import RedsysValidationException, RedsysPaymentException
+from tpv.models import PaymentTPV
+from tpv.settings import ERROR_CODES
+
+
+def compute_signature(salt, payload, key):
+    """
+    :param salt: order number (Ds_Order or Ds_Merchant_Order)
+    :param payload: Ds_MerchantParameters
+    :param key: shared secret (aka key) from the Redsys Administration Module
+    :return:
+    """
+    b64_key = base64.b64decode(key)
+
+    des3 = pyDes.triple_des(
+        b64_key, mode=pyDes.CBC, IV="\0" * 8, pad="\0", padmode=pyDes.PAD_NORMAL
+    )
+    pepper = des3.encrypt(str(salt))
+
+    payload_hash = hmac.new(pepper, payload.encode(), hashlib.sha256).digest()
+    return base64.b64encode(payload_hash)
+
+
+def compare_signatures(signature_1, signature_2):
+    alphanumeric_characters = re.compile("[^a-zA-Z0-9]")
+    sig1safe = re.sub(alphanumeric_characters, "", signature_1)
+    sig2safe = re.sub(alphanumeric_characters, "", signature_2)
+    return sig1safe == sig2safe
+
+
+def validate_payment_for_order(request, order: PaymentTPV) -> Decimal:
+    """
+    example_response_data = {
+        'Ds_MerchantCode': '999008881',
+        'Ds_Terminal': '001',
+        'Ds_Order': 'a082bd1cda0b488786f23a62e89107c0',
+        'Ds_Amount': '13532',
+        'Ds_Currency': '978',
+        'Ds_Date': '20/03/2024',
+        'Ds_Hour': '12:21',
+        'Ds_SecurePayment': '1',
+        'Ds_Card_Number': '454881******1156',
+        'Ds_Card_Country': '724',
+        'Ds_Response': '0000',
+        'Ds_MerchantData': '',
+        'Ds_TransactionType': '0',
+        'Ds_ConsumerLanguage': '1',
+        'Ds_AuthorisationCode': '182670',
+        'Ds_Card_Brand': '1',
+        'Ds_ProcessedPayMethod': '80',
+        'Ds_ECI': '05',
+        'Ds_Response_Description': 'OPERACION AUTORIZADA'
+    }
+
+    :param request:
+    :param order:
+    :return:
+    """
+    data = request.POST
+
+    merchant_parameters = data.get("Ds_MerchantParameters")
+
+    if not merchant_parameters:
+        raise RedsysValidationException(
+            _("No se ha recibido ningún valor para Ds_MerchantParameters")
+        )
+
+    merchant_params = base64.b64decode(merchant_parameters).decode()
+    result = json.loads(merchant_params)
+
+    order_hex = result.get("Ds_Order")
+    assert order_hex == order.hash.hex
+
+    status_code = result.get("Ds_Response")
+
+    if int(status_code) > 100:
+        reason = ERROR_CODES.get(status_code, _("Error no tipificado"))
+
+        raise RedsysPaymentException(_(f"No se ha realizado el pago. Motivo: {reason}"))
+
+    amount = Decimal(result.get("Ds_Amount")) / 100
+
+    return amount
+
+
+def pay_order(order: PaymentTPV, amount_paid: Decimal):
+    order.status = PaymentTPV.StatusChoices.PAID
+    order.save()