RSA

rsa.py

#!/bin/python
# @itseco
# https://es.wikipedia.org/wiki/RSA

import sys

p1 = 53
p2 = 59
n = p1 * p2
fn = (p1-1) * (p2-1)
e = 3
message = sys.argv[1]

print "Generate private key for Alice"
d = (2*fn+1) / e
print "d = %d" % d

print "Generate public key for Alice..."
print "n = %d" % n
print "e = %d" % e

def encrypt(message, n, e):
    ciphertext = []
    for char in message:
        ciphertext.append((ord(char)**e) % n)
    return ciphertext

print "Bob sent encrypted message to Alice using Alice's public key..."
ciphertext = encrypt(message, n, e)
print ciphertext

def decrypt(ciphertext, d, n):
    message = []
    for char in ciphertext:
        message.append(chr((char**d)%n))
    return message

print "Alice decrypt message with his private key..."
print decrypt(ciphertext, d, n)

"""
root@kali:~# python rsa.py "Hello world"
Generate private key for Alice
d = 2011
Generate public key for Alice...
n = 3127
e = 3
Bob sent encrypted message to Alice using Alice's public key...
[1135, 1518, 2658, 2658, 1132, 1498, 2833, 1132, 2473, 2658, 2487]
Alice decrypt message with his private key...
['H', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd']
"""