HTTPS明文劫持之證書僞造(Python)

爲了防止網絡中的明文信息的在傳輸過程中被截獲，SSL/TLS爲各種應用協議加密封裝提供了一個不錯的解決方案，作爲一種公開的加密協議，採用非對稱加密的方式來傳輸密鑰無疑爲數據通信提供了不錯的安全保障。由於現今的計算機還未達到在有限時間破解出私鑰(RSA)，所以想成功的截獲明文信息，只能通過中間人僞造證書這種方式了，但是SSL/TLS協議在設計時就考慮到這一點，採用了CA機構證書籤名的方式來防止這個問題，因此要想做到真正的做到證書僞造，除非你有可信任的CA機構的私鑰（或者應用本身設計存在缺陷），這樣可以爲自己簽發證書，正常情況下我們是不可能弄到這些的。說了這麼多其實想說明SSL/TLS協議至少目前來說還是安全的，所以想截獲HTTPS的明文，你先得導入事先自己製作好的CA根證書(怎麼製作根證書以及簽發證書等等，可以查看下Openssl的文檔)，廢話不多說具體看代碼，只是通過一個簡單https代理來體現，代碼比較簡單，作用只是實現HTTPS的證書僞造的具體過程。

 

 

import os
import socket  
import threading  
import re  
import time  
import random
import ssl  
from M2Crypto import X509, EVP, RSA, ASN1  


CACerFile='ca.cer'  
  
CAKeyFile='ca.key'  

StoreFolder='certs/'

mutex = threading.Lock()

def gen_rand_serial(len):
    num=''
    nlist= random.sample(['1','2','3','4','5','6','7','9','0','a', 'b', 'c', 'd','e','f'], len)
    for n in nlist :
        num+=str(n) 
	return int(num.encode('hex'),16)
	
def mk_cert():  
    
    serial = gen_rand_serial(4)
    cert = X509.X509()   
    cert.set_serial_number(serial)  
    cert.set_version(2)  
    mk_cert_valid(cert)  
    cert.add_ext(X509.new_extension('nsComment', 'SSL sever'))  
    return cert  
  
def mk_cert_valid(cert, days=180):  
  
    t = long(time.time())  
    now = ASN1.ASN1_UTCTIME()  
    now.set_time(t - 24*60*60)  
    expire = ASN1.ASN1_UTCTIME()  
    expire.set_time(t + days * 24 * 60 * 60)  
    cert.set_not_before(now)  
    cert.set_not_after(expire)  
  
  
def mk_request(bits, cn='localhost'):  
  
    pk = EVP.PKey()  
    x = X509.Request()  
    rsa = RSA.gen_key(bits, 65537, lambda: None)  
    pk.assign_rsa(rsa)  
    x.set_pubkey(pk)  
    name = x.get_subject()  
    name.C = "CN"  
    name.CN = cn  
    name.ST = 'TS'  
    name.O = 'TS'  
    name.OU = 'TS'  
    x.sign(pk,'sha1')  
    return x, pk  
  
def mk_self_cert(cacert_file, ca_key_file, cn):  
  
    cert_req, pk2 = mk_request(2048, cn=cn)  
      
    if cacert_file and ca_key_file:  
        cacert = X509.load_cert(cacert_file)  
        pk1 = EVP.load_key(ca_key_file)  
    else:  
        cacert = None  
        pk1 = None  
      
    cert = mk_cert()  
    cert.set_subject(cert_req.get_subject())  
    cert.set_pubkey(cert_req.get_pubkey())  
      
    if cacert and pk1:  
        cert.set_issuer(cacert.get_issuer())  
        cert.sign(pk1, 'sha256')  
    else:  
        cert.set_issuer(cert.get_subject())  
        cert.sign(pk2, 'sha256')  
          
    with open(StoreFolder+cn+'.cer', 'w') as f:  
        f.write(cert.as_pem())  
    with open(StoreFolder+cn+'.key', 'w') as f:  
        f.write(pk2.as_pem(None))  
  
  
def RecviceMessage(ss):  
    head=''  
    method=''  
    isFrist=True  
    while (True):  
        try:  
            buf= ss.recv(2048)        
            if(len(buf)>0):   
                head+=buf  
            else:  
                break  
            if isFrist:  
                i=head.find(' ')  
                method=head[0:i]  
                isFrist=False  
        except Exception,e:    
                print "Recvice Browser Data Fail"  
                break  
                            
        if("\r\n\r\n" in head):   
            patten=method+'+( http| https)(://)+([^/])+(/)'              
            reobj = re.compile(patten)    
            result, number = reobj.subn(method+' /', head)  
            req=result.replace("Proxy-Connection:","Connection:")  
            print req  
  
            if method=="CONNECT":  
				#t = threading.Thread(target=FakeHttps,args=(result,ss))  
				#t.start()  
                FakeHttps(result,ss)  
            else:  
                #t = threading.Thread(target=ForWardHttp,args=(result,ss))  
                #t.start()
                ForWardHttp(result,ss)
                  
def ForWardHttp(msg,ss):  
    host=''  
    port=80  
    patten2=r'(Host: )+(\S+)'  
    searchObj2 = re.search( patten2, msg, re.M|re.I)  
    if searchObj2:    
         host=searchObj2.group(2)  
         #print host  
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)   
    if(isinstance(ss,ssl.SSLSocket)):   
       sock=ssl.wrap_socket(sock)  
       port=443  
          
    try:  
        ip=socket.gethostbyname(host)   
        sock.connect((ip, port))  
    except Exception,e:  
        print e,"Connect Fail"  
        return   
          
    sock.send(msg)  
    while (True):  
        try:  
            rec=sock.recv(2048)  
            if(len(rec)>0):  
                ss.send(rec)  
            else:  
                break  
                 
        except Exception,e:  
            print e,'Recvice Data Fail'  
            sock.close()  
            ss.close()  
            break  
  
def FakeHttps(result,ss):  
    index=result.find(':')  
      
    Host=result[len('CONNECT '):index]  
      
    ss.send('HTTP/1.1 200 Connection Established\r\n\r\n')  
    
    mutex.acquire()
    mk_self_cert(CACerFile,CAKeyFile,Host)                    #Make a self signed certificate  
    mutex.release()
    #os.system('FakeSSL.exe '+Host)
    conn = ssl.wrap_socket(ss,keyfile=StoreFolder+Host+".key",certfile=StoreFolder+Host+".cer",server_side=True)  
  
    RecviceMessage(conn)  
  
  
if __name__ == "__main__":  
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)  
    sock.bind(('0.0.0.0',8080))  
    sock.listen(50)
    while(True):  
        clientSock, address = sock.accept()   
        t = threading.Thread(target=RecviceMessage,args=(clientSock,))  
        t.start()  

 

 

 

 

 

 

 

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