fix: update the checksum logic

payments/payment_gateways/doctype/paytm_settings/checksum.py

@@ -2,141 +2,79 @@ import base64
 import string
 import random
 import hashlib
+import sys
 
 from Crypto.Cipher import AES
 
 
-IV = "@@@@&&&&####$$$$"
+iv = '@@@@&&&&####$$$$'
 BLOCK_SIZE = 16
 
-
-def generate_checksum(param_dict, merchant_key, salt=None):
-	params_string = __get_param_string__(param_dict)
-	salt = salt if salt else __id_generator__(4)
-	final_string = '%s|%s' % (params_string, salt)
-
-	hasher = hashlib.sha256(final_string.encode())
-	hash_string = hasher.hexdigest()
-
-	hash_string += salt
-
-	return __encode__(hash_string, IV, merchant_key)
-
-
-def generate_refund_checksum(param_dict, merchant_key, salt=None):
-	for i in param_dict:
-		if("|" in param_dict[i]):
-			param_dict = {}
-			exit()
-	params_string = __get_param_string__(param_dict)
-	salt = salt if salt else __id_generator__(4)
-	final_string = '%s|%s' % (params_string, salt)
-
-	hasher = hashlib.sha256(final_string.encode())
-	hash_string = hasher.hexdigest()
-
-	hash_string += salt
-
-	return __encode__(hash_string, IV, merchant_key)
-
-
-def generate_checksum_by_str(param_str, merchant_key, salt=None):
-	params_string = param_str
-	salt = salt if salt else __id_generator__(4)
-	final_string = '%s|%s' % (params_string, salt)
-
-	hasher = hashlib.sha256(final_string.encode())
-	hash_string = hasher.hexdigest()
-
-	hash_string += salt
-
-	return __encode__(hash_string, IV, merchant_key)
-
-
-def verify_checksum(param_dict, merchant_key, checksum):
-	# Remove checksum
-	if 'CHECKSUMHASH' in param_dict:
-		param_dict.pop('CHECKSUMHASH')
-
-	# Get salt
-	paytm_hash = __decode__(checksum, IV, merchant_key)
+if (sys.version_info > (3, 0)):
+	__pad__ = lambda s: bytes(s + (BLOCK_SIZE - len(s) % BLOCK_SIZE) * chr(BLOCK_SIZE - len(s) % BLOCK_SIZE), 'utf-8')
+else:
+	__pad__ = lambda s: s + (BLOCK_SIZE - len(s) % BLOCK_SIZE) * chr(BLOCK_SIZE - len(s) % BLOCK_SIZE)
+
+__unpad__ = lambda s: s[0:-ord(s[-1])]
+
+def encrypt(input, key):
+	input = __pad__(input)
+	c = AES.new(key.encode("utf8"), AES.MODE_CBC, iv.encode("utf8"))
+	input = c.encrypt(input)
+	input = base64.b64encode(input)
+	return input.decode("UTF-8")
+
+def decrypt(encrypted, key):
+	encrypted = base64.b64decode(encrypted)
+	c = AES.new(key.encode("utf8"), AES.MODE_CBC, iv.encode("utf8"))
+	param = c.decrypt(encrypted)
+	if type(param) == bytes:
+		param = param.decode()
+	return __unpad__(param)
+
+def generateSignature(params, key):
+	if not type(params) is dict and not type(params) is str:
+		raise Exception("string or dict expected, " + str(type(params)) + " given")
+	if type(params) is dict:
+		params = getStringByParams(params)
+	return generateSignatureByString(params, key)
+
+def verifySignature(params, key, checksum):
+	if not type(params) is dict and not type(params) is str:
+		raise Exception("string or dict expected, " + str(type(params)) + " given")
+	if "CHECKSUMHASH" in params:
+		del params["CHECKSUMHASH"]
+		
+	if type(params) is dict:
+		params = getStringByParams(params)
+	return verifySignatureByString(params, key, checksum)
+
+def generateSignatureByString(params, key):
+	salt = generateRandomString(4)
+	return calculateChecksum(params, key, salt)
+
+def verifySignatureByString(params, key, checksum):
+	paytm_hash = decrypt(checksum, key)    
 	salt = paytm_hash[-4:]
-	calculated_checksum = generate_checksum(
-		param_dict, merchant_key, salt=salt)
-	return calculated_checksum == checksum
+	return paytm_hash == calculateHash(params, salt)
 
+def generateRandomString(length):
+	chars = string.ascii_uppercase + string.digits + string.ascii_lowercase
+	return ''.join(random.choice(chars) for _ in range(length))
 
-def verify_checksum_by_str(param_str, merchant_key, checksum):
-	# Remove checksum
-	# if 'CHECKSUMHASH' in param_dict:
-		# param_dict.pop('CHECKSUMHASH')
-
-	# Get salt
-	paytm_hash = __decode__(checksum, IV, merchant_key)
-	salt = paytm_hash[-4:]
-	calculated_checksum = generate_checksum_by_str(
-		param_str, merchant_key, salt=salt)
-	return calculated_checksum == checksum
-
-
-def __id_generator__(size=6, chars=string.ascii_uppercase + string.digits + string.ascii_lowercase):
-	return ''.join(random.choice(chars) for _ in range(size))
-
-
-def __get_param_string__(params):
+def getStringByParams(params):
 	params_string = []
 	for key in sorted(params.keys()):
-		if("REFUND" in params[key] or "|" in params[key]):
-			exit()
-		value = params[key]
-		params_string.append('' if value == 'null' else str(value))
+		value = params[key] if params[key] is not None and params[key].lower() != "null" else ""
+		params_string.append(str(value))
 	return '|'.join(params_string)
 
+def calculateHash(params, salt):
+	finalString = '%s|%s' % (params, salt)
+	hasher = hashlib.sha256(finalString.encode())
+	hashString = hasher.hexdigest() + salt
+	return hashString
 
-def __pad__(s): return s + (BLOCK_SIZE - len(s) %
-							BLOCK_SIZE) * chr(BLOCK_SIZE - len(s) % BLOCK_SIZE)
-
-
-def __unpad__(s): return s[0:-ord(s[-1])]
-
-
-def __encode__(to_encode, iv, key):
-	# Pad
-	to_encode = __pad__(to_encode)
-	# Encrypt
-	c = AES.new(key, AES.MODE_CBC, iv)
-	to_encode = c.encrypt(to_encode)
-	# Encode
-	to_encode = base64.b64encode(to_encode)
-	return to_encode.decode("UTF-8")
-
-
-def __decode__(to_decode, iv, key):
-	# Decode
-	to_decode = base64.b64decode(to_decode)
-	# Decrypt
-	c = AES.new(key, AES.MODE_CBC, iv)
-	to_decode = c.decrypt(to_decode)
-	if type(to_decode) == bytes:
-		# convert bytes array to str.
-		to_decode = to_decode.decode()
-	# remove pad
-	return __unpad__(to_decode)
-
-
-if __name__ == "__main__":
-	params = {
-		"MID": "mid",
-		"ORDER_ID": "order_id",
-		"CUST_ID": "cust_id",
-		"TXN_AMOUNT": "1",
-		"CHANNEL_ID": "WEB",
-		"INDUSTRY_TYPE_ID": "Retail",
-		"WEBSITE": "xxxxxxxxxxx"
-	}
-
-	print(verify_checksum(
-		params, 'xxxxxxxxxxxxxxxx',
-		"CD5ndX8VVjlzjWbbYoAtKQIlvtXPypQYOg0Fi2AUYKXZA5XSHiRF0FDj7vQu66S8MHx9NaDZ/uYm3WBOWHf+sDQAmTyxqUipA7i1nILlxrk="))
-
-	# print(generate_checksum(params, "xxxxxxxxxxxxxxxx"))
+def calculateChecksum(params, key, salt): 
+	hashString = calculateHash(params, salt)
+	return encrypt(hashString, key)

payments/payment_gateways/doctype/paytm_settings/paytm_settings.json

@@ -9,7 +9,7 @@
   "merchant_key",
   "staging",
   "column_break_4",
-  "industry_type",
+  "industry_type_id",
   "website"
  ],
  "fields": [
@@ -18,43 +18,55 @@
    "fieldtype": "Data",
    "in_list_view": 1,
    "label": "Merchant ID",
-   "reqd": 1
+   "reqd": 1,
+   "show_days": 1,
+   "show_seconds": 1
   },
   {
    "fieldname": "merchant_key",
    "fieldtype": "Password",
    "in_list_view": 1,
    "label": "Merchant Key",
-   "reqd": 1
+   "reqd": 1,
+   "show_days": 1,
+   "show_seconds": 1
   },
   {
    "default": "0",
    "fieldname": "staging",
    "fieldtype": "Check",
-   "label": "Staging"
-  },
-  {
-   "depends_on": "eval: !doc.staging",
-   "fieldname": "industry_type",
-   "fieldtype": "Data",
-   "label": "Industry Type",
-   "mandatory_depends_on": "eval: !doc.staging"
+   "label": "Staging",
+   "show_days": 1,
+   "show_seconds": 1
   },
   {
    "depends_on": "eval: !doc.staging",
    "fieldname": "website",
    "fieldtype": "Data",
    "label": "Website",
-   "mandatory_depends_on": "eval: !doc.staging"
+   "mandatory_depends_on": "eval: !doc.staging",
+   "show_days": 1,
+   "show_seconds": 1
   },
   {
    "fieldname": "column_break_4",
-   "fieldtype": "Column Break"
+   "fieldtype": "Column Break",
+   "show_days": 1,
+   "show_seconds": 1
+  },
+  {
+   "depends_on": "eval: !doc.staging",
+   "fieldname": "industry_type_id",
+   "fieldtype": "Data",
+   "label": "Industry Type ID",
+   "mandatory_depends_on": "eval: !doc.staging",
+   "show_days": 1,
+   "show_seconds": 1
   }
  ],
  "issingle": 1,
  "links": [],
- "modified": "2020-04-16 14:16:19.687449",
+ "modified": "2020-06-08 13:36:09.703143",
  "modified_by": "Administrator",
  "module": "Integrations",
  "name": "Paytm Settings",

payments/payment_gateways/doctype/paytm_settings/paytm_settings.py

@@ -13,7 +13,7 @@ from frappe import _
 from frappe.utils import get_url, call_hook_method, cint, flt, cstr
 from frappe.integrations.utils import create_request_log, create_payment_gateway
 from frappe.utils import get_request_site_address
-from frappe.integrations.doctype.paytm_settings.checksum import generate_checksum, verify_checksum
+from frappe.integrations.doctype.paytm_settings.checksum import generateSignature, verifySignature
 from frappe.utils.password import get_decrypted_password
 
 class PaytmSettings(Document):
@@ -75,7 +75,7 @@ def get_paytm_params(payment_details, order_id, paytm_config):
 		"CALLBACK_URL" : redirect_uri,
 	})
 
-	checksum = generate_checksum(paytm_params, paytm_config.merchant_key)
+	checksum = generateSignature(paytm_params, paytm_config.merchant_key)
 
 	paytm_params.update({
 		"CHECKSUMHASH" : checksum
@@ -101,7 +101,7 @@ def verify_transaction(**kwargs):
 
 	if paytm_params and paytm_config and paytm_checksum:
 		# Verify checksum
-		is_valid_checksum = verify_checksum(paytm_params, paytm_config.merchant_key, paytm_checksum)
+		is_valid_checksum = verifySignature(paytm_params, paytm_config.merchant_key, paytm_checksum)
 
 	if is_valid_checksum and received_data['RESPCODE'] == '01':
 		verify_transaction_status(paytm_config, received_data['ORDERID'])
@@ -118,7 +118,7 @@ def verify_transaction_status(paytm_config, order_id):
 		ORDERID= order_id
 	)
 
-	checksum = generate_checksum(paytm_params, paytm_config.merchant_key)
+	checksum = generateSignature(paytm_params, paytm_config.merchant_key)
 	paytm_params["CHECKSUMHASH"] = checksum
 
 	post_data = json.dumps(paytm_params)