From 3f13fba95551ae871addd8c2c602d722d38665b0 Mon Sep 17 00:00:00 2001
From: sayampradhan <112542130+sayampradhan@users.noreply.github.com>
Date: Sat, 15 Oct 2022 01:20:56 +0530
Subject: [PATCH] Clean Code

---
 PayTm/Checksum.py | 57 +++++++++++++++++++++++++++--------------------
 1 file changed, 33 insertions(+), 24 deletions(-)

diff --git a/PayTm/Checksum.py b/PayTm/Checksum.py
index 841d625..7fffccb 100644
--- a/PayTm/Checksum.py
+++ b/PayTm/Checksum.py
@@ -14,7 +14,7 @@
 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)
+    final_string = "%s|%s" % (params_string, salt)
 
     hasher = hashlib.sha256(final_string.encode())
     hash_string = hasher.hexdigest()
@@ -23,14 +23,15 @@ def generate_checksum(param_dict, merchant_key, salt=None):
 
     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]):
+        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)
+    final_string = "%s|%s" % (params_string, salt)
 
     hasher = hashlib.sha256(final_string.encode())
     hash_string = hasher.hexdigest()
@@ -43,7 +44,7 @@ def generate_refund_checksum(param_dict, merchant_key, salt=None):
 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)
+    final_string = "%s|%s" % (params_string, salt)
 
     hasher = hashlib.sha256(final_string.encode())
     hash_string = hasher.hexdigest()
@@ -55,8 +56,8 @@ def generate_checksum_by_str(param_str, merchant_key, salt=None):
 
 def verify_checksum(param_dict, merchant_key, checksum):
     # Remove checksum
-    if 'CHECKSUMHASH' in param_dict:
-        param_dict.pop('CHECKSUMHASH')
+    if "CHECKSUMHASH" in param_dict:
+        param_dict.pop("CHECKSUMHASH")
 
     # Get salt
     paytm_hash = __decode__(checksum, IV, merchant_key)
@@ -64,10 +65,11 @@ def verify_checksum(param_dict, merchant_key, checksum):
     calculated_checksum = generate_checksum(param_dict, merchant_key, salt=salt)
     return calculated_checksum == checksum
 
+
 def verify_checksum_by_str(param_str, merchant_key, checksum):
     # Remove checksum
-    #if 'CHECKSUMHASH' in param_dict:
-        #param_dict.pop('CHECKSUMHASH')
+    # if 'CHECKSUMHASH' in param_dict:
+    # param_dict.pop('CHECKSUMHASH')
 
     # Get salt
     paytm_hash = __decode__(checksum, IV, merchant_key)
@@ -76,32 +78,35 @@ def verify_checksum_by_str(param_str, merchant_key, checksum):
     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 __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):
     params_string = []
     for key in sorted(params.keys()):
-        if("REFUND" in params[key] or "|" in params[key]):
+        if "REFUND" in params[key] or "|" in params[key]:
             respons_dict = {}
             exit()
         value = params[key]
-        params_string.append('' if value == 'null' else str(value))
-    return '|'.join(params_string)
+        params_string.append("" if value == "null" else str(value))
+    return "|".join(params_string)
 
 
-__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])]
+__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 __encode__(to_encode, iv, key):
     # Pad
     to_encode = __pad__(to_encode)
     # Encrypt
-    c = AES.new(key.encode('utf-8'), AES.MODE_CBC, iv.encode('utf-8'))
-    to_encode = c.encrypt(to_encode.encode('utf-8'))
+    c = AES.new(key.encode("utf-8"), AES.MODE_CBC, iv.encode("utf-8"))
+    to_encode = c.encrypt(to_encode.encode("utf-8"))
     # Encode
     to_encode = base64.b64encode(to_encode)
     return to_encode.decode("UTF-8")
@@ -111,7 +116,7 @@ def __decode__(to_decode, iv, key):
     # Decode
     to_decode = base64.b64decode(to_decode)
     # Decrypt
-    c = AES.new(key.encode('utf-8'), AES.MODE_CBC, iv.encode('utf-8'))
+    c = AES.new(key.encode("utf-8"), AES.MODE_CBC, iv.encode("utf-8"))
     to_decode = c.decrypt(to_decode)
     if type(to_decode) == bytes:
         # convert bytes array to str.
@@ -128,11 +133,15 @@ def __decode__(to_decode, iv, key):
         "TXN_AMOUNT": "1",
         "CHANNEL_ID": "WEB",
         "INDUSTRY_TYPE_ID": "Retail",
-        "WEBSITE": "xxxxxxxxxxx"
+        "WEBSITE": "xxxxxxxxxxx",
     }
 
-    print(verify_checksum(
-        params, 'xxxxxxxxxxxxxxxx',
-        "CD5ndX8VVjlzjWbbYoAtKQIlvtXPypQYOg0Fi2AUYKXZA5XSHiRF0FDj7vQu66S8MHx9NaDZ/uYm3WBOWHf+sDQAmTyxqUipA7i1nILlxrk="))
+    print(
+        verify_checksum(
+            params,
+            "xxxxxxxxxxxxxxxx",
+            "CD5ndX8VVjlzjWbbYoAtKQIlvtXPypQYOg0Fi2AUYKXZA5XSHiRF0FDj7vQu66S8MHx9NaDZ/uYm3WBOWHf+sDQAmTyxqUipA7i1nILlxrk=",
+        )
+    )
 
-    # print(generate_checksum(params, "xxxxxxxxxxxxxxxx"))
\ No newline at end of file
+    # print(generate_checksum(params, "xxxxxxxxxxxxxxxx"))