Applied_Python_Cryptography/_3.4.3_3DES_CBC.py at main · AnasZaatreh/Applied_Python_Cryptography · GitHub

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from Crypto.Cipher import DES3
from Crypto.Util.Padding import pad, unpad
from Crypto.Random import get_random_bytes

def DES3_CBC_encrypt(plaintext, DES3_key, initialization_vector):

    DES3_CBC_cipher = DES3.new(DES3_key, DES3.MODE_CBC, iv= initialization_vector)

    ciphertext = DES3_CBC_cipher.encrypt(pad(plaintext, DES3.block_size))

    return ciphertext


def DES3_CBC_decrypt(ciphertext, DES3_key, initialization_vector):

    DES3_CBC_cipher = DES3.new(DES3_key, DES3.MODE_CBC, iv= initialization_vector)
    decrypted_plaintext = unpad(DES3_CBC_cipher.decrypt(ciphertext), DES3.block_size)

    return decrypted_plaintext


plaintext = input("Enter DES3 Plaintext : ").encode()

DES3_key  = DES3.adjust_key_parity(get_random_bytes(24))

initialization_vector = get_random_bytes(8)

ciphertext = DES3_CBC_encrypt(plaintext, DES3_key, initialization_vector)

decrypted_plaintext = DES3_CBC_decrypt(ciphertext, DES3_key, initialization_vector)

print("Encode PT:", plaintext)

print("Secret_Key: ", str(DES3_key.hex()))
print("IV        : ", initialization_vector.hex())

print("Ciphertext: ", ciphertext.hex())
print("Decrypted : ", decrypted_plaintext.decode())