python利用pycrypto实现RSA

本节内容

  1. pycrypto模块简介
  2. RSA的公私钥生成
  3. RSA使用公钥加密数据
  4. RSA使用私钥解密密文
  5. pycrypto模块简介

pycrypto模块是python中用来处理加密解密等信息安全相关的一个很重要模块。

该模块支持的加密方式：

  1. 对称加密方式：
  1. AES
  2. DES
  3. ARC4
  1. 散列值计算：
  1. MD5
  2. SHA
  3. HMAC
  1. 公钥加密和签名：
  1. RSA
  2. DSA

基本上常见的关于信息安全类的算法都可以支持，所以，这是一个很强大的模块。

安装方式：pip install pycrypto
如果在windows上的python3.5中安装完成之后导入from Crypto import Random模块失败，需要找到python35安装目录下的Lib\site-packages\Crypto\Random\OSRNG\nt.py文件，将import winrandom修改成from . import winrandom

关于加密方式的了解可以看我这边博客：加密方式介绍关于非对称加密算法（RSA）的使用可以看我这篇博客：数字签名和数字证书

RSA的公私钥生成

 

from Crypto import Random
from Crypto.PublicKey import RSA


# 伪随机数生成器
random_generator = Random.new().read
# rsa算法生成实例
rsa = RSA.generate(1024, random_generator)

# master的秘钥对的生成
private_pem = rsa.exportKey()

#--------------------------------------------生成公私钥对文件-----------------------------------------------------------
with open('master-private.pem', 'wb') as f:
    f.write(private_pem)

public_pem = rsa.publickey().exportKey()
with open('master-public.pem', 'wb') as f:
    f.write(public_pem)

#---------------------------------------------------
# ghost的秘钥对的生成
private_pem = rsa.exportKey()
with open('ghost-private.pem', 'wb') as f:
    f.write(private_pem)

public_pem = rsa.publickey().exportKey()
with open('ghost-public.pem', 'wb') as f:
    f.write(public_pem)

#-----------------------------------生成的公私钥文件类似于如下形式-------------------------------------------------------
# 私钥
-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----

#公钥
-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC6mwuOxuqYi6mugLGr3OuiHwm/
hF4kQX1zd5VhGwxYf4H5+pkOCES2UjOyLP9Xh6w+DJtRwTGE2xwDd3wMfW2wkHij
M/uHkM9Jt+oRGIjy4IiXo+7tue/NWBkDiQm1qte0YDKlmkFREwvZ5X2KaCsSx+dy
KH4QsovxQ3/RxftdmQIDAQAB
-----END PUBLIC KEY-----

RSA使用公私钥加解密数据

 

from Crypto.PublicKey import RSA
from Crypto.Cipher import PKCS1_v1_5 as Cipher_pkcs1_v1_5
import base64

message = 'hello ghost, this is a plian text'
with open('ghost-public.pem',"r") as f:
     key = f.read()
     rsakey = RSA.importKey(key)  # 导入读取到的公钥
     cipher = Cipher_pkcs1_v1_5.new(rsakey)  # 生成对象
     cipher_text = base64.b64encode(cipher.encrypt(message.encode(encoding="utf-8")))  # 通过生成的对象加密message明文，注意，在python3中加密的数据必须是bytes类型的数据，不能是str类型的数据
     print(cipher_text)

with open('ghost-private.pem') as f:
    key = f.read()
    rsakey = RSA.importKey(key)  # 导入读取到的私钥
    cipher = Cipher_pkcs1_v1_5.new(rsakey)  # 生成对象
    text = cipher.decrypt(base64.b64decode(cipher_text), "ERROR")  # 将密文解密成明文，返回的是一个bytes类型数据，需要自己转换成str
    print(text)
# 结果：
b'meBtYXP35VNjtWXsONDluweXdG98tMHjb5GxBLFJ0GJzo+96wSrHe8SDhNJweDJP6/OdeIQ8jP1HKCK+aC9HA12YMSUUqcixsY5s8QUyTs+fkMjGrlC6I7hPLO4DGQbFXEY0jiqP9ycgmAi5FCsDMcm0oEm8/fVzv7vl9QarSN4='  # 加密后的密文
b'hello ghost, this is a plian text'  # 解密后的明文