Why isn't my 5 layer RSA encryption working properly? the decryption doesn't return the right value

Question

When I decrypt the 5 levels RSA encrypted message the result isn't the original message although I use the right private keys and the right private keys

I have already tried playing with the integers and the amount of encryptions. It's working if I only encrypt once

import Crypto
from Crypto.PublicKey import RSA
from Crypto import Random
import ast

publickeys = []
privatekeys = []

for i in range (0,5):
    random_generator = Random.new().read
    key = RSA.generate(1024, random_generator)
    privatekeys.append(key)
    publickeys.append(key.publickey())

data = "ack"

for publickey in publickeys:
    data = publickey.encrypt(str(data), 32)

for i in range (1,len(privatekeys)+1):
    data = privatekeys[-i].decrypt(ast.literal_eval(str(tuple(data))))

There are no error messages but the results aren't what I expected. instead of getting the right message "ack" I am getting a weird string.

chepner · Answer 1 · 2019-11-07T14:32:14.667

0

Discard the None value returned by encrypt; it doesn't help you to keep it around, and greatly complicates decoding the encrypted string.

for publickey in publickeys:
    data, _ = publickey.encrypt(data, 32)

for privatekey in reversed(privatekeys):
    data = privatekey.decrypt(data)

edited Nov 07 '19 at 14:32

answered Nov 07 '19 at 13:42

chepner

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What `None` value? – President James K. Polk Nov 07 '19 at 14:28
Read the documentation for `encrypt`. It returns a tuple whose first element is the encrypted message and whose second element is always `None`. (I fixed the answer to actually do what I said you should do.) – chepner Nov 07 '19 at 14:31
Ah, this is PyCrypto, I see. Also, maybe OP is using python 2 as well. – President James K. Polk Nov 07 '19 at 15:03

Why isn't my 5 layer RSA encryption working properly? the decryption doesn't return the right value

1 Answers1