使用Python和OpenSSL简单模拟加密通信

准备阶段

import os,shutil
from Crypto.Cipher import DES3,XOR
def xorencode(data,key):
mm=XOR.new(key)
cc=mm.encrypt(data)
return cc
def xordecode(data,key):
cc=XOR.new(key)
mm=cc.decrypt(data)
return mm
print "创建用户文件夹用于模拟通信"
os.mkdir("Auser")
os.mkdir("Buser")
print "用户文件夹Auser、Buser创建完成"
print "生成主密钥和基本密钥"
AKMfile=open("Auser/KM",'w+')
BKMfile=open("Buser/KM",'w+')
akm=randkey(8)
AKMfile.write(akm)
AKMfile.flush()
print "用户A的主密钥为"+akm.encode('hex')
bkm=randkey(8)
BKMfile.write(bkm)
AKMfile.flush()
print "用户B的主密钥为"+bkm.encode('hex')
#生成共享密钥
ABkey=randkey(32)
print "共享密钥为"+ABkey.encode('hex')
#用户A加密存储
ABkeyA=xorencode(ABkey,akm)
ABkeyfileA=open("Auser/KEK",'w+')
ABkeyfileA.write(ABkeyA)
ABkeyfileA.flush()
#用户B加密存储
ABkeyB=xorencode(ABkey,bkm)
ABkeyfileB=open("Buser/KEK",'w+')
ABkeyfileB.write(ABkeyB)
ABkeyfileB.flush()
print "模拟准备完成"

用户A产生并发送消息

from OpenSSL.rand import bytes as randkey
import os,shutil
from Crypto.Cipher.AES import *
from Crypto.Cipher import DES3,XOR
def AESencode(data, key, IV):  # AES加密
addlen = 16 - len(data) % 16
data = data + addlen * chr(addlen)
tocode = new(key, 2, IV)
encode = tocode.encrypt(data)
return encode

def AESdecode(code, key, IV):  # AES解密
tomm = new(key, 2, IV)
mm = tomm.decrypt(code)
return mm
def des3encode(data,key,IV):
# MODE_CBC = 2
# MODE_CFB = 3
# MODE_CTR = 6
# MODE_ECB = 1
# MODE_OFB = 5
# MODE_OPENPGP = 7
# MODE_PGP = 4
mm=DES3.new(key,3,IV)
cc=mm.encrypt(data)
return cc

def des3encode(data,key,IV):
addlen = 16 - len(data) % 16
data = data + addlen * chr(addlen)
# MODE_CBC = 2
# MODE_CFB = 3
# MODE_CTR = 6
# MODE_ECB = 1
# MODE_OFB = 5
# MODE_OPENPGP = 7
# MODE_PGP = 4
mm=DES3.new(key,3,IV)
cc=mm.decrypt(data)
return cc
def xorencode(data,key):
mm=XOR.new(key)
cc=mm.encrypt(data)
return cc
def xordecode(data,key):
cc=XOR.new(key)
mm=cc.decrypt(data)
return mm
message='''
你是烧鸡吗？当你收到此加密消息时，我十分激动的告诉你：
你这门课挂了！
哈哈哈哈哈哈哈哈哈哈哈！
'''
AKMfile=open("Auser/KM",'r')
akm=AKMfile.read(8)
ABkeyfileA=open("Auser/KEK",'r')
ABkey=ABkeyfileA.read(16)
ABkey=xordecode(ABkey,akm)#解密出加密密钥
talkkeym=randkey(32)
talkkeyfile=open("Auser/talkkey",'w')
talkkeyfile.write(talkkeym)
talkkeyfile.close()
talkkeyc=des3encode(talkkeym,ABkey,'01020304')
messagecc=AESencode(message,talkkeyc,'1234567887654321')
messagefile=open("Auser/message",'w')
messagefile.write(messagecc)
messagefile.close()
print "消息加密已完成\n消息递送中..........."
shutil.copyfile("Auser/talkkey","Buser/talkkey")
shutil.copyfile("Auser/message","Buser/message")
print "消息传递完成"

用户B收到消息后的操作

BKMfile=open("Buser/KM",'r')
bkm=BKMfile.read(8)
ABkeyfileB=open("Buser/KEK",'r')
ABkey=ABkeyfileB.read(16)
ABkey=xordecode(ABkey,bkm)#解密出加密密钥
talkkeyfile=open("Buser/talkkey",'r')
talkkeym=talkkeyfile.read(32)
talkkeyc=des3encode(talkkeym,ABkey,'01020304')
messagefile=open("Buser/message",'r')
lens=os.path.getsize("Buser/message")
messagecc=messagefile.read(lens)
message=AESdecode(messagecc,talkkeyc,'1234567887654321')
print message