simple encrypt/decrypt lib in python with private key

Question

Is there a simple way to encrypt/decrypt a string with a key?

Something like:

key = '1234' string =  'hello world' encrypted_string = encrypt(key, string) decrypt(key, encrypted_string) 

I couldn't find anything simple to do that.

Answer 1

pyDES is a DES and Triple-DES implementation completely written in python.

Here's a simple and portable example that should be secure enough for basic string encryption needs. Just put the pyDES module in the same folder as your program and try it out:

Sender's computer

>>> from pyDES import *  # pyDes if installed from pip >>> ciphertext = triple_des('a 16 or 24 byte password').encrypt("secret message", padmode=2)  #plain-text usually needs padding, but padmode = 2 handles that automatically >>> ciphertext ')\xd8\xbfFn#EY\xcbiH\xfa\x18\xb4\xf7\xa2'  #gibberish 

Recipient's computer

>>> from pyDES import * >>> plain_text = triple_des('a 16 or 24 byte password').decrypt(')\xd8\xbfFn#EY\xcbiH\xfa\x18\xb4\xf7\xa2', padmode=2) >>> plain_text "secret message" 

---

You might get an error in Python3 from code of Recipient's computer

ValueError: pyDes can only work with encoded strings, not Unicode.

from pyDes import *  a = b')\xd8\xbfFn#EY\xcbiH\xfa\x18\xb4\xf7\xa2' plain_text = triple_des('a 16 or 24 byte password').decrypt(a, padmode=2) print(plain_text) 

Just Add b at the beginning of the encrypted text. For clearer code, assign it to a new variable (in this case, it's a, and decrypt a in a normal way).

Answer 2

http://www.dlitz.net/software/pycrypto/ should do what you want.

Taken from their docs page.

>>> from Crypto.Cipher import DES >>> obj=DES.new('abcdefgh', DES.MODE_ECB) >>> plain="Guido van Rossum is a space alien." >>> len(plain) 34 >>> obj.encrypt(plain) Traceback (innermost last):   File "<stdin>", line 1, in ? ValueError: Strings for DES must be a multiple of 8 in length >>> ciph=obj.encrypt(plain+'XXXXXX') >>> ciph '\021,\343Nq\214DY\337T\342pA\372\255\311s\210\363,\300j\330\250\312\347\342I\3215w\03561\303dgb/\006' >>> obj.decrypt(ciph) 'Guido van Rossum is a space alien.XXXXXX'