Skip to content

Clean Code #12

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Clean Code #12

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
57 changes: 33 additions & 24 deletions PayTm/Checksum.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -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()
Expand All @@ -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()
Expand All @@ -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()
Expand All @@ -55,19 +56,20 @@ 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)
salt = paytm_hash[-4:]
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)
Expand All @@ -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")
Expand All @@ -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.
Expand All @@ -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"))
# print(generate_checksum(params, "xxxxxxxxxxxxxxxx"))