python使用rsa非对称加密

1、安装rsa

支持python 2.7 或者 python 3.5 以上版本

使用豆瓣pypi源来安装rsa

pip install -i https://pypi.douban.com/simple rsa

2、加密解密

2.1、生成公私钥对

import rsa

# 1、接收者(A)生成512位公私钥对
# a. lemon_pub为PublicKey对象, lemon_priv为PrivateKey对象
# b. 512为秘钥的位数, 可以自定义指定, 例如: 128、256、512、1024、2048等
lemon_pub, lemon_priv = rsa.newkeys(512)

此时的状态

2.2、发送者加密

# 2、发送者(B)使用接收者(A)的公钥去加密消息
# rsa只能处理字节类型, 故字符串类型需要转化为字节类型
love_talk = "Lemon little girl, I love you very much!".encode("utf-8")
cryto_info = rsa.encrypt(love_talk, lemon_pub)    # 使用接收者(A)的公钥加密

此时状态

2.3、接收者解密

# 3. 接收者(A)使用自己的私钥去解密消息
talk_real = rsa.decrypt(cryto_info, lemon_priv)
talk_real2 = talk_real.decode("utf-8")
print(talk_real2)

3、其他场景加密解密

import rsa

# 生成密钥
pubkey, privkey = rsa.newkeys(512)

# 保存密钥
print("==============保存密钥===============")
with open('public.pem' ,'w+') as f:
    f.write(pubkey.save_pkcs1().decode())
with open('private.pem' ,'w+') as f:
    f.write(privkey.save_pkcs1().decode())

#导入密钥
with open('public.pem' ,'r') as f:
    pubkey = rsa.PublicKey.load_pkcs1(f.read().encode())
with open('private.pem' ,'r') as f:
    privkey = rsa.PrivateKey.load_pkcs1(f.read().encode())

"""
加密 RSA
"""
def rsa_encrypt(message):
    crypto_email_text = rsa.encrypt(message.encode(), pubkey)
    return crypto_email_text

text = rsa_encrypt("first test rsa")
print(text)

"""
解密
"""
def rsa_decrypt(message):
    message_str = rsa.decrypt(message,privkey).decode()
    return message_str

newmessage=rsa_encrypt("haha,one two three four smile!")
message = rsa_decrypt(newmessage)
print("\n",message)

"""
签名
"""

message = '这是重要指令：...'
crypto_email_text = rsa.sign(message.encode(), privkey, 'SHA-1')

"""
验证
"""
# 收到指令明文、密文，然后用公钥验证，进行身份确认
rsa.verify(message.encode(), crypto_email_text, pubkey)

4、加密过程的封装

# 导入base64模块来进行base64编码
import base64
import rsa

class HandleSign:
    # 定义服务器公钥, 往往可以存放在公钥文件中
    server_pub = """
        -----BEGIN PUBLIC KEY-----
        MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDQENQujkLfZfc5Tu9Z1LprzedE
        O3F7gs+7bzrgPsMl29LemonPYvIG8C604CprLittlenJpnhWu2lGirlWZyLq6sBr
        tuPorOc42+gInFfyhJAwdZB6Sqlove7bW+jNe5youDtU7very6Gx+muchGo8Dg+S
        kKlZFc8Br7SHtbL2tQIDAQAB
        -----END PUBLIC KEY-----
        """

    @classmethod
    def to_encrypt(cls, msg, pub_key=None):
        """
        非对称加密
        :param msg: 待加密字符串或者字节
        :param pub_key: 公钥
        :return: base64密文字符串
        """
        if isinstance(msg, str):            # 如果msg为字符串, 则转化为字节类型
            msg = msg.encode('utf-8')
        elif isinstance(msg, bytes):        # 如果msg为字节类型, 则无需处理
            pass
        else:                               # 否则抛出异常
            raise TypeError('msg必须为字符串或者字节类型!')

        if not pub_key:                     # 如果pub_key为空, 则使用全局公钥
            pub_key = cls.server_pub.encode("utf-8")
        elif isinstance(pub_key, str):      # 如果pub_key为字符串, 则转化为字节类型
            pub_key = pub_key.encode('utf-8')
        elif isinstance(pub_key, bytes):    # 如果msg为字节类型, 则无需处理
            pass
        else:                               # 否则抛出异常
            raise TypeError('pub_key必须为None、字符串或者字节类型!')

        public_key_obj = rsa.PublicKey.load_pkcs1_openssl_pem(pub_key)  # 创建 PublicKey 对象
        #2.创建 PublicKey 对象
        #public_key_obj = rsa.PublicKey.load_pkcs1(pub_key)

        cryto_msg = rsa.encrypt(msg, public_key_obj)  # 生成加密文本
        cipher_base64 = base64.b64encode(cryto_msg)   # 将加密文本转化为 base64 编码

        return cipher_base64.decode()   # 将字节类型的 base64 编码转化为字符串类型

if __name__ == '__main__':
    # 待加密字符串或者字节
    love_talk = "Lemon little girl, I love you very much!"

    #1.用自己生成的publickye测试下
    #lemon_pub,lemon_priv=rsa.newkeys(512)
    #lemon_pub2=lemon_pub.save_pkcs1()

    # 调用to_encrypt类方法来进行加密
    cryto_info = HandleSign.to_encrypt(love_talk)
    print(cryto_info)