原文链接: python pycrypto 加密解密

上一篇: 面试链表问题 汇总

下一篇: sympy 解决常见高数问题

参考

http://www.cnblogs.com/huxianglin/p/6387045.html

如果引入模块报错，需要使用conda重新安装

RSA 密码算法与签名
RSA是一种公钥密码算法，RSA的密文是对代码明文的数字的 E 次方求mod N 的结果。也就是将明文和自己做E次乘法，然后再将其结果除以 N 求余数，余数就是密文。RSA是一个简洁的加密算法。E 和 N 的组合就是公钥（public key）。

对于RSA的解密，即密文的数字的 D 次方求mod N 即可，即密文和自己做 D 次乘法，再对结果除以 N 求余数即可得到明文。D 和 N 的组合就是私钥（private key）。

算法的加密和解密还是很简单的，可是公钥和私钥的生成算法却不是随意的。本文在于使用，对生成秘钥对的算法就暂时忽略。使用 Pycrypto生成秘钥对很简单，我们分别为 Master和Ghost各生成一对属于自己的秘钥对。

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

加密与解密
通常通信的时候，发送者使用接受者的公钥加密，接受者使用接受者私钥解密。

简而言之，Master给Ghost通信，需要加密内容，那么Ghost会生成一个秘钥对，Ghost的公钥ghost-public.pem和私钥ghost-private.pem 。Ghost 把公钥公开给发送者，任何人都可以用来加密，然后Master使用ghost-public.pem进行加密，然后把内容发给Ghost，Ghost再使用ghost-private.pem进行解密。

from Crypto.PublicKey import RSA
from Crypto.Cipher import PKCS1_v1_5 as Cipher_pkcs1_v1_5
import base64message = '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strprint(text)b'fpczMFuc9vhsOlQ9pGnIKkblwCaNtTdp2vrUEVA9pu1UgKStcxmJ8+qqZ05lvJoTGeSaNN1meC4uHjnbvOCv7vsV36pT9OGl0ygCvV94hZiPNQEUk4slFUBrY8dOKmRfzP5pvruN6+T6BEyzaPWLnAKzIZ0ZiVDBPFHkEClelV4='
b'hello ghost, this is a plian text'

from Crypto import Random
from Crypto.Hash import SHA
from Crypto.Cipher import PKCS1_v1_5 as Cipher_pkcs1_v1_5
from Crypto.Signature import PKCS1_v1_5 as Signature_pkcs1_v1_5
from Crypto.PublicKey import RSA
import base64message = b'hello ghost, this is a plian text'
with open('ghost-public.pem') as f:key = f.read()rsakey = RSA.importKey(key)cipher = Cipher_pkcs1_v1_5.new(rsakey)cipher_text = base64.b64encode(cipher.encrypt(message))print(cipher_text)with open('ghost-private.pem') as f:key = f.read()rsakey = RSA.importKey(key)cipher = Cipher_pkcs1_v1_5.new(rsakey)text = cipher.decrypt(base64.b64decode(cipher_text), "ERROR")print(text)
b'Gs8InVgp+TNQcsvu70svZBCzTFY0Bs8k49Son6XYQBYPudw8S7VHBZW4y7aAgvQuEHv4ZoNrbc4fn6EbTs8TGQ42eAAhF2TVJkvAk6J0rCh3AbmdlXZ1vRS2IFpRFO33XbnGRDUzt7oOJf4QuQzXFznVVPcXBxKNMQogDpyG5L8='
b'hello ghost, this is a plian text'

这样Ghost就能看到Master所发的内容了，当然，如果Ghost想要给Master发消息，就需要Master先把其的公钥给Ghost，后者再使用公钥加密，然后发送给Master，最后Master使用自己的私钥解密。

签名与验签
当然，对于窃听者，有时候也可以对伪造Master给Ghost发送内容。为此出现了数字签名。也就是Master给Ghost发送消息的时候，先对消息进行签名，表明自己的身份，并且这个签名无法伪造。具体过程即Master使用自己的私钥对内容签名，然后Ghost使用Master的公钥进行验签。

签名

from Crypto import Random
from Crypto.Hash import SHA
from Crypto.Cipher import PKCS1_v1_5 as Cipher_pkcs1_v1_5
from Crypto.Signature import PKCS1_v1_5 as Signature_pkcs1_v1_5
from Crypto.PublicKey import RSA
import base64message = 'hello ghost, this is a plian text'
with open('master-private.pem') as f:key = f.read()rsakey = RSA.importKey(key)signer = Signature_pkcs1_v1_5.new(rsakey)digest = SHA.new()digest.update(message.encode('utf8'))sign = signer.sign(digest)signature = base64.b64encode(sign)
print(signature)b'K9D0VTIMYP9kzxg7LEt7BVGSgWAXUPrwtnIROFdn4qgYZrTLshBMzApajA22ErmXlVOWI4mkmlEvgN40OoAoJgJxXQj3yyII6sXw8usp11RlLYx1XoB2tfFx4gp/Rr/CsNC6NNommLKnJhqSJeP/v7veaayZwGAwEuEPF8qzocw='

检签

from Crypto import Random
from Crypto.Hash import SHA
from Crypto.Cipher import PKCS1_v1_5 as Cipher_pkcs1_v1_5
from Crypto.Signature import PKCS1_v1_5 as Signature_pkcs1_v1_5
from Crypto.PublicKey import RSA
import base64
signature = b'K9D0VTIMYP9kzxg7LEt7BVGSgWAXUPrwtnIROFdn4qgYZrTLshBMzApajA22ErmXlVOWI4mkmlEvgN40OoAoJgJxXQj3yyII6sXw8usp11RlLYx1XoB2tfFx4gp/Rr/CsNC6NNommLKnJhqSJeP/v7veaayZwGAwEuEPF8qzocw='
message = b'hello ghost, this is a plian text'
with open('master-public.pem') as f:key = f.read()rsakey = RSA.importKey(key)verifier = Signature_pkcs1_v1_5.new(rsakey)digest = SHA.new()# Assumes the data is base64 encoded to begin withdigest.update(message)is_verify = verifier.verify(digest, base64.b64decode(signature))print(is_verify)True