Use RSA to encrypt in JavaScript and decrypt in Python3

问题

I'm developing a website using this JS plugin to encrypt some data and send it to the server: https://github.com/travist/jsencrypt

I'm running Python 3 with Django, the problem is I can't decrypt the data on the server. My code is:

JS Code:

pkey = "-----BEGIN PUBLIC KEY-----\
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDeVs9mcWUtTgi93/KXMNA/IF7S\
oQcZAmKQueygoDp9XUM3xnxPb/6XNpJQII85Hxbljqs/xuPVtxo5ovyJ+XXIPV8+\
eG6kSDmr2C3NpBUtfoUeADC/1H1jy44T6stBgXGMwTPokhjvSyEbGpkgMGo74Rpq\
q1vHofh3KcPNoaYH4wIDAQAB\
-----END PUBLIC KEY-----";


var encrypter = new JSEncrypt;
encrypter.setPublicKey(pkey);
encrypter.encrypt('Testing...');

And I get:

"STg7Fnm6Y6cAgMXEt4SxP8rbMb/pFB2X9Y1z8pAOoCNO9y8XuhVmQuG/FRBSqM+3ge43x9kfYMideAUu69RothwEOYmNnVrfwqm7SLm3voEcSXCqst2S7prTmCvYW43WyAAUl0vNxV+7xsm/yciQ4XV+jZSKd3xidbWL1BTTUw8="

Python Code:

from Crypto.PublicKey import RSA
from Crypto.Cipher import PKCS1_OAEP
from base64 import *


def decrypt(key, text):
    if type(key) == str:
        key = key.encode()
    if type(text) == str:
        text = text.encode()

    rsakey = RSA.importKey(key)
    rsakey = PKCS1_OAEP.new(rsakey)
    d = rsakey.decrypt(text)
    return d

text = "STg7Fnm6Y6cAgMXEt4SxP8rbMb/pFB2X9Y1z8pAOoCNO9y8XuhVmQuG/FRBSqM+3ge43x9kfYMideAUu69RothwEOYmNnVrfwqm7SLm3voEcSXCqst2S7prTmCvYW43WyAAUl0vNxV+7xsm/yciQ4XV+jZSKd3xidbWL1BTTUw8="

text = b64decode(text.encode())

with open('private.pem', 'rb') as f:
    key = f.read()
decrypt(key, text)

And I get:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.2/dist-packages/Crypto/Cipher/PKCS1_OAEP.py", line 227, in decrypt
    raise ValueError("Incorrect decryption.")
ValueError: Incorrect decryption.

The private key I'm using in this example is:

If I try to decrypt it on JS it works as intended:

private = "-----BEGIN RSA PRIVATE KEY-----\
MIICWwIBAAKBgQCO9YbJ8Z+tW0ucnMdXGNzmcvWaaLRGsx5iUHslbZ1tjec63HDm\
6Hr2hv56u5zytyF4Cd/0lBNRC9qf/1XlEFqeSRifsyHZpPfyZn0fbHWYLH8g5FE4\
VqrMe79ubSVx2eGWwwaLvEO+yaO1AF/fxWT6Ir8AUikMFFAnX+fBaA3XIwIDAQAB\
AoGADxuniQP+CgYR8ZUoA+5eugQALLdQBgC7/0veF9CDyKYsf634SI7dH9yYXEQj\
jAsKgHMatfBIMlJ8YlhLrY+S4+r26goNEqygtqetJ6NuePKQQ8xEERP4icsaBpY7\
WqeU6AZOMlyq8o+e4DMnuxGpf8UT+lLx1G9AmVJf3+6NONECQQDLX94BmW//48Y6\
yg9wnO6TR1msrGd1PFRqyJ9eilj8chI2JxiHkhepiTlBU7eyjUv4aeE7U84mp3Zo\
AtPoiKmlAkEAs/OQM9IDttfgdS/yK6vZr1myNAbKOdv1rVId7MAspGHbN//gzb4s\
r4mZKsIAi+jaDhpMvYbUxJe9y5HAY3XTJwJAe3hcZEQvRv+WHaMG9KuR/EBZJQgW\
V4qlBZ9/gfokRD9M5yudLNF5JCh3Zj3ZTMGT2eEOKOKcScNpk4QD+yzdMQJAQlSM\
Gd3WyqXmMav7qwdMVStN2YmLLyqZ80oqh6MKkYkUgh7KYWwxEn84ux8JjojFH5+o\
G9BASzrXldrivIaozwJAVAHr9ON/altcDyh/OjkJff/3xXzHB3Zxvy4WykkO/PdF\
tOqpAnYso3mCsEQsCcrJCflkFmJuYsvu4+Tm4GiqVg==\
-----END RSA PRIVATE KEY-----\
"
text = "STg7Fnm6Y6cAgMXEt4SxP8rbMb/pFB2X9Y1z8pAOoCNO9y8XuhVmQuG/FRBSqM+3ge43x9kfYMideAUu69RothwEOYmNnVrfwqm7SLm3voEcSXCqst2S7prTmCvYW43WyAAUl0vNxV+7xsm/yciQ4XV+jZSKd3xidbWL1BTTUw8="

encrypter.setPrivateKey(private);
encrypter.decrypt(text);

And I get:

"Testing"

But I just can't make it work on Python.

What am I doing wrong?

回答1:

jsencrypt depends on the jsbn library which doesn't provide OAEP, but only PKCS#1 v1.5 padding.

You have to use the same in python which PyCrypto provides. Simply use PKCS1_v1_5 instead of PKCS1_OAEP.

Note that PKCS#1 v1.5 padding shouldn't be used today anymore. I suggest you use the forge library which provides an RSA implementation with OAEP.

回答2:

Using PKCS1_v1_5:

def decrypt(key, text):
    if type(key) == str:
        key = key.encode()
    if type(text) == str:
        text = text.encode()

    rsakey = RSA.importKey(key)
    rsakey = PKCS1_v1_5.new(rsakey)
    d = rsakey.decrypt(text, 'bollox')
    return d

>>> decrypt(text, key)
b'Testing'

回答3:

I had been using JSEncrypt JavaScript file to achieve conversation between JavaScript and Python using pycrypto however during encryption in JavaScript it uses a random pad in the function pkcs1pad2 which needed to be removed and it started working. It had been a hack but it worked out. Following are the lines are commented out from function pkcs1pad2(s,n)

while(n > 2) { // random non-zero pad
    x[0] = 0;
    while(x[0] == 0) rng.nextBytes(x);
    ba[--n] = x[0];
  }

  ba[--n] = 2;
  ba[--n] = 0;

来源：https://stackoverflow.com/questions/29581319/use-rsa-to-encrypt-in-javascript-and-decrypt-in-python3

标签

python

python-3.x

encryption

rsa

pycrypto