Kali pertama

CHANGES.txt

+0.1 11-3-2021
+-------------
+- Kali pertama

README.rst

+LinkAja Encryption
+==================
+
+Ini berisi class yang digunakan untuk melakukan encrypt dan decrypt data
+LinkAja, produk PT Telkom.
+
+Contoh penggunaannya ada di direktori ``test``. Untuk mengujinya pasang dulu
+paket yang dibutuhkan::
+
+    $ ~/env/bin/pip install pytest
+
+Lalu jalankan::
+
+    $ ~/env/bin/pytest test/payment.py
+
+Selamat mencoba.

linkaja/crypt/__init__.py

+import base64
+import hashlib
+from Crypto.Cipher import AES
+
+
+BLOCK_SIZE = 16
+
+
+def pad(s):
+    p = len(s)
+    sisa = p % BLOCK_SIZE
+    sisa = BLOCK_SIZE - sisa
+    tambahan = sisa * chr(sisa)
+    return s + tambahan
+
+
+def unpad(s):
+    p = len(s)
+    i = p - 1
+    raw = s[i:]
+    i = ord(raw)
+    return s[:-i]
+
+
+class Crypt:
+    def __init__(self, key):
+        key = key.encode('utf-8')
+        key = hashlib.sha256(key)
+        self.key = key.digest()
+
+    def encrypt(self, raw, iv):
+        iv = iv.encode('utf-8')
+        raw = pad(raw)
+        raw = raw.encode('utf-8')
+        cipher = AES.new(self.key, AES.MODE_CBC, iv)
+        raw_crypted = cipher.encrypt(raw)
+        raw_salted = iv + raw_crypted
+        return base64.b64encode(raw_salted)
+
+    def decrypt(self, raw_b64):
+        raw_salted = base64.b64decode(raw_b64)
+        iv = raw_salted[:16]
+        raw_crypted = raw_salted[16:]
+        cipher = AES.new(self.key, AES.MODE_CBC, iv)
+        raw = cipher.decrypt(raw_crypted)
+        raw = unpad(raw)
+        return bytes.decode(raw)

linkaja/crypt/payment.py

+from datetime import datetime
+from . import Crypt as BaseCrypt
+
+
+begin_unix_time = datetime(1970, 1, 1)
+
+
+def create_iv():
+    durasi = datetime.utcnow() - begin_unix_time
+    detik = durasi.total_seconds()
+    detik = int(detik)
+    return str(detik) + '000000'
+
+
+class Crypt(BaseCrypt):
+    def encrypt(self, raw):
+        iv = create_iv()
+        return super().encrypt(raw, iv)

setup.py

+import os
+from setuptools import (
+    setup,
+    find_packages,
+    )
+
+
+here = os.path.abspath(os.path.dirname(__file__))
+with open(os.path.join(here, 'README.rst')) as f:
+    README = f.read()
+with open(os.path.join(here, 'CHANGES.txt')) as f:
+    CHANGES = f.read()
+
+line = CHANGES.splitlines()[0]
+version = line.split()[0]
+
+requires = [
+    'PyCryptodome',
+    ]
+
+tests_require = [
+    'pytest',
+    ]
+
+setup(
+    name='linkaja-crypt',
+    version=version,
+    description='Enkripsi LinkAja',
+    long_description=README + '\n\n' + CHANGES,
+    author='Owo Sugiana',
+    author_email='sugiana@gmail.com',
+    license='PostgreSQL License',
+    extras_require={
+        'testing': tests_require,
+    },
+    packages=find_packages(),
+    install_requires=requires,
+    zip_safe=False,
+    )

test/payment.py

+import unittest
+import json
+from linkaja.crypt.payment import Crypt
+
+
+class Coba(unittest.TestCase):
+    def test_encrypt(self):
+        d = dict(invoice_id='1234')
+        raw1 = json.dumps(d)
+        key = '1234'
+        c = Crypt(key)
+        crypted = c.encrypt(raw1)
+        raw2 = c.decrypt(crypted)
+        self.assertEqual(raw1, raw2)
+
+
+if __name__ == '__main__':
+    unittest.main()