# -*- coding: utf-8 -*-

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

# 加密解密：公钥加密，私钥解密

#

# 签名验签：私钥签名，公钥验签

#

# 生成 private key and pulic key

print "1、生成 private key and pulic key"

# 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()

with open('master-private.pem', 'w') as f:

    f.write(private_pem)

public_pem = rsa.publickey().exportKey()

with open('master-public.pem', 'w') as f:

    f.write(public_pem)

# ghost的秘钥对的生成

private_pem = rsa.exportKey()

with open('ghost-private.pem', 'w') as f:

    f.write(private_pem)

public_pem = rsa.publickey().exportKey()

with open('ghost-public.pem', 'w') as f:

    f.write(public_pem)

# 加密和解密

print "2、加密和解密"

# Master使用Ghost的公钥对内容进行rsa 加密

message = 'hello ghost, this is a plian text'

print "message: " + message

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 "加密（encrypt）"

    print cipher_text

# Ghost使用自己的私钥对内容进行rsa 解密

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), random_generator)

    print "解密（decrypt）"

    print "message:" + text

    assert text == message, 'decrypt falied'

# 签名与验签

print "3、 签名与验签"

# Master 使用自己的私钥对内容进行签名

print "签名"

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)

    sign = signer.sign(digest)

    signature = base64.b64encode(sign)

print signature

print "验签"

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 with

    digest.update(message)

    is_verify = verifier.verify(digest, base64.b64decode(signature))

print is_verify