Python（00）：RSA加解密

一、rsa库（推荐）

1、公钥加密、私钥解密

# -*- coding: utf-8 -*-
import rsa

# rsa加密
def rsaEncrypt(str):
    # 生成公钥、私钥
    (pubkey, privkey) = rsa.newkeys(512)
    print("pub: ", pubkey)
    print("priv: ", privkey)
    # 明文编码格式
    content = str.encode('utf-8')
    # 公钥加密
    crypto = rsa.encrypt(content, pubkey)
    return (crypto, privkey)


# rsa解密
def rsaDecrypt(str, pk):
    # 私钥解密
    content = rsa.decrypt(str, pk)
    con = content.decode('utf-8')
    return con


(a, b) = rsaEncrypt("hello")
print('加密后密文：'+ a)
content = rsaDecrypt(a, b)
print('解密后明文：'+ content)

2、密钥导出、签名验证

import rsa

# 先生成一对密钥，然后保存.pem格式文件，当然也可以直接使用
(pubkey, privkey) = rsa.newkeys(1024)

pub = pubkey.save_pkcs1()
pubfile = open('public.pem', 'wb')
pubfile.write(pub)
pubfile.close()

pri = privkey.save_pkcs1()
prifile = open('private.pem', 'wb')
prifile.write(pri)
prifile.close()

# load公钥和密钥
message = 'lovesoo.org'
with open('public.pem', "rb") as publickfile:
    p = publickfile.read()
    pubkey = rsa.PublicKey.load_pkcs1(p)
    print(pubkey)

with open('private.pem', "rb") as privatefile:
    p = privatefile.read()
    privkey = rsa.PrivateKey.load_pkcs1(p)
    print(privkey)

# 用公钥加密、再用私钥解密
crypto = rsa.encrypt(message.encode('utf-8'), pubkey)
message = rsa.decrypt(crypto, privkey)
message = message.decode('utf-8')
print (message)

# sign 用私钥签名认证、再用公钥验证签名
signature = rsa.sign(message.encode('utf-8'), privkey, 'SHA-1')
verify = rsa.verify('lovesoo.org'.encode('utf-8'), signature, pubkey)
print(verify)

二、使用 Crypto.PublicKey.RSA库

1、使用 Crypto.PublicKey.RSA 生成公钥、私钥：

import Crypto.PublicKey.RSA
import Crypto.Random
 
x = Crypto.PublicKey.RSA.generate(2048)

#  Crypto.PublicKey.RSA.generate(2048, Crypto.Random.new().read)   使用 Crypto.Random.new().read 伪随机数生成器
a = x.exportKey("PEM")  # 生成私钥
b = x.publickey().exportKey()   # 生成公钥

with open("a.pem", "wb") as x:
    x.write(a)
with open("b.pem", "wb") as x:
    x.write(b)

2、使用 Crypto.PublicKey.RSA.importKey(private_key) 生成公钥和证书：

import Crypto.PublicKey.RSA
 
with open("a.pem", "rb") as x:
    xx = Crypto.PublicKey.RSA.importKey(x.read())
 
b = xx.publickey().exportKey()   # 生成公钥
with open("b.pem", "wb") as x:
    x.write(b)
    
a = xx.exportKey("DER")   # 生成 DER 格式的证书
with open("a.der", "wb") as x:
    x.write(a)

3、使用 Crypto进行RSA加解密

import Crypto.PublicKey.RSA
import Crypto.Cipher.PKCS1_v1_5
import Crypto.Random
import Crypto.Signature.PKCS1_v1_5
import Crypto.Hash
 
y = b"abcdefg1234567"
 
with open("b.pem", "rb") as x:
    b = x.read()
    cipher_public = Crypto.Cipher.PKCS1_v1_5.new(Crypto.PublicKey.RSA.importKey(b))
    cipher_text = cipher_public.encrypt(y) # 使用公钥进行加密

with open("a.pem", "rb") as x:
    a = x.read()
    # 如果私钥有密码 则使用相应密码 Crypto.PublicKey.RSA.importKey(a, password)
    cipher_private = Crypto.Cipher.PKCS1_v1_5.new(Crypto.PublicKey.RSA.importKey(a))
    text = cipher_private.decrypt(cipher_text, Crypto.Random.new().read)    # 使用私钥进行解密
assert text == y    # 断言验证
 
with open("c.pem", "rb") as x:
    c = x.read()
    c_rsa = Crypto.PublicKey.RSA.importKey(c)
    signer = Crypto.Signature.PKCS1_v1_5.new(c_rsa)
    msg_hash = Crypto.Hash.SHA256.new()
    msg_hash.update(y)
    sign = signer.sign(msg_hash)    # 使用私钥进行'sha256'签名

with open("d.pem", "rb") as x:
    d = x.read()
    d_rsa = Crypto.PublicKey.RSA.importKey(d)
    verifer = Crypto.Signature.PKCS1_v1_5.new(d_rsa)
    msg_hash = Crypto.Hash.SHA256.new()
    msg_hash.update(y)
    verify = verifer.verify(msg_hash, sign) # 使用公钥验证签名
    print(verify)