How to use AES Encryption and Decryption from Scala to Python

Question

I have a code in scala where I have my encryption and decryption code, It works fine and the code is:

import java.util.Base64
import javax.crypto.Cipher
import javax.crypto.spec.{IvParameterSpec, SecretKeySpec}
class Encryption {
val key = "enIntVecTest2020"
val initVector = "encryptionIntVec"

def encrypt(text: String): String = {

val  iv = new IvParameterSpec(initVector.getBytes("UTF-8"))
val  skeySpec = new SecretKeySpec(key.getBytes("UTF-8"), "AES")

val  cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING")
cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv)

val  encrypted = cipher.doFinal(text.getBytes())
return Base64.getEncoder().encodeToString(encrypted)
}

def decrypt(text:String) :String={
val  iv = new IvParameterSpec(initVector.getBytes("UTF-8"))
val  skeySpec = new SecretKeySpec(key.getBytes("UTF-8"), "AES")

val  cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING")
cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv)
val  original = cipher.doFinal(Base64.getDecoder.decode(text))

new String(original)
}
}

val encryptobj = new Encryption()
val pwd = "#test@12345"
val result =encryptobj.encrypt(pwd)

pwd: String = #test@12345
result: String = lHhq1OzMSYnj+0XxiNzKhQ==

val pwd1  = encryptobj.decrypt(result)
println(pwd1)

pwd1: String = #test@12345
#test@12345

I tried in Python to achieve the same but does not give the expected encryption result, here is my code(I took the help of other similar answers):

from hashlib import sha256
import base64
from Crypto import Random
from Crypto.Cipher import AES

BS = 16
pad = lambda s: bytes(s + (BS - len(s) % BS) * chr(BS - len(s) % BS), 'utf-8')
unpad = lambda s : s[0:-ord(s[-1:])]

class AESCipher:

    def __init__( self, key ):
        self.key = bytes(key, 'utf-8')

    def encrypt( self, raw ):
        raw = pad(raw)
        iv = "encryptionIntVec".encode('utf-8')
        cipher = AES.new(self.key, AES.MODE_CBC, iv )
        return base64.b64encode( iv + cipher.encrypt( raw ) )

    def decrypt( self, enc ):
        enc = base64.b64decode(enc)
        iv = enc[:16]
        cipher = AES.new(self.key, AES.MODE_CBC, iv )
        return unpad(cipher.decrypt( enc[16:] )).decode('utf8')

    cipher = AESCipher('enIntVecTest2020')
    encrypted = cipher.encrypt('#test@12345')
    decrypted = cipher.decrypt(encrypted)
    
    print(encrypted)

b'ZW5jcnlwdGlvbkludFZlY5R4atTszEmJ4/tF8YjcyoU='

As you can see both the encryption is not right, I don't know where I am doing wrong. Please help in achieving the same encrypting result in python as showing in scala, I would be much thankful.

In the Python code, IV and ciphertext are concatenated during encryption and separated during decryption, in the Scala code concatenation and separation are missing. Therefore the ciphertexts differ. The design of the Python code corresponds to common practice, but instead of a fixed IV, a for each encryption randomly generated IV is used. — Topaco, Jul 13 '20 at 10:41
Oh my bad, it was such a silly mistake. Thankyou @Topaco for letting me know. — Mohammad Rijwan, Jul 13 '20 at 10:57

score 5 · Accepted Answer · answered Jul 14 '20 at 16:37

Thanks to @Topaco answer and after some search it worked.

import base64
from Crypto.Cipher import AES

BS = 16
pad = lambda s: bytes(s + (BS - len(s) % BS) * chr(BS - len(s) % BS), 'utf-8')
unpad = lambda s : s[0:-ord(s[-1:])]
class AESCipher:

    def __init__( self, key ):
        self.key = bytes(key, 'utf-8')

    def encrypt( self, raw ):
        raw = pad(raw)
        iv = "encryptionIntVec".encode('utf-8')
        cipher = AES.new(self.key, AES.MODE_CBC, iv )
        return base64.b64encode(cipher.encrypt( raw ) )
    def decrypt( self, enc ):
        iv = "encryptionIntVec".encode('utf-8')
        enc = base64.b64decode(enc)
        cipher = AES.new(self.key, AES.MODE_CBC, iv )
        return unpad(cipher.decrypt( enc )).decode('utf8')
cipher = AESCipher('enIntVecTest2020')
encrypted = cipher.encrypt('#test@12345')
print(encrypted.decode('utf-8'))
-> lHhq1OzMSYnj+0XxiNzKhQ==
decrypted = cipher.decrypt(encrypted)
print(decrypted)
-> #test@12345

How to use AES Encryption and Decryption from Scala to Python

1 Answers1