iapbr7fd

1import base64
2import hashlib
3
4from Crypto.Cipher import AES
5
6
7class EncryptParameters:
8    # The block size to be used while padding
9    BS = 16
10
11    def __init__(self, secret_key, iv_key):
12        """Initialises the Class with the parameters passed.
13
14        :param secret_key:
15        The secret key to use in the symmetric cipher.
16        It must be 16 bytes long
17        :type secret_key: string
18
19        :param iv_key:
20        The initialization vector key to use in the symmetric cipher.
21        It must be 16 bytes long
22        :type iv_key: string
23        """
24
25        # Hash the secret key
26        self.secret_key_hash = hashlib.sha256(secret_key.encode()).hexdigest()[:32]
27
28        # Hash the IV Key
29        self.iv_hash = hashlib.sha256(iv_key.encode()).hexdigest()[:16]
30
31    def pad(self, string):
32        """Introduces extra bytes for strings less than the block size
33
34        :param string:
35        The string value of the text to be padded
36        :type string: string
37
38        :return: string
39        """
40        return string + (self.BS - len(string) % self.BS) * chr(self.BS - len(string) % self.BS)
41
42    def encrypt(self, params):
43        """Encrypts the params passed with the IV and secret key passed while initializing this class
44
45        :param params:
46        The string value of the text to be encrypted
47        :type params: string
48
49        :return: string: Encrypted string
50        """
51        cipher = AES.new(self.secret_key_hash.encode(), AES.MODE_CBC, self.iv_hash.encode())
52
53        string = cipher.encrypt(self.pad(params).encode())
54        return base64.b64encode(base64.b64encode(string))