公开密钥加密 RSA

rsa.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# 参考资料:
# * https://en.wikipedia.org/wiki/RSA
# 
# Show RSA document:
# > from Crypto.PublicKey import RSA
# > help(RSA)

from Crypto.PublicKey import RSA
from Crypto import Random

KEY_LENGTH = 1024


def generate_key(key_length=KEY_LENGTH):
    random_generator = Random.new().read
    return RSA.generate(key_length, random_generator)


def encrypt(public_key, plaintext):
    key = RSA.importKey(public_key)
    return key.encrypt(plaintext, 0)[0]


def decrypt(private_key, ciphertext):
    key = RSA.importKey(private_key)
    return key.decrypt(ciphertext)


if __name__ == '__main__':
    key = generate_key()
    public_key = key.publickey().exportKey()
    private_key = key.exportKey()

    plaintext = 'abc'
    ciphertext = encrypt(public_key, plaintext)
    plaintext = decrypt(private_key, ciphertext)
    print plaintext
    print ciphertext