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Burp extension: extract CSRF tokens from responses of selected Burp tools and update them with a custom session handling rule.
from burp import (IBurpExtender, IBurpExtenderCallbacks, ISessionHandlingAction, IHttpListener)
import re
class BurpExtender(IBurpExtender, ISessionHandlingAction, IHttpListener):
def registerExtenderCallbacks(self, callbacks):
self.callbacks = callbacks
self.helpers = callbacks.getHelpers()
callbacks.setExtensionName("Session CSRF Token Handling")
self.callbacks.registerSessionHandlingAction(self)
self.callbacks.registerHttpListener(self)
self.out = callbacks.getStdout()
# CONFIG: find token in tools defined by this bitmask, constants defined in IBurpExtenderCallback
self.findTools = 0xffffffff
# CONFIG: this RE matches the CSRF token
self.reFindToken = re.compile("^<script>var csrfToken=\"(.*?)\"", re.MULTILINE)
# CONFIG: Replacement RE with prefix and suffix capture groups
self.reReplaceToken = re.compile("(CSRFToken=).*?(&)")
self.token = None
def log(self, msg):
self.out.write(msg + "\n")
### IHttpListener ###
def processHttpMessage(self, tool, messageIsRequest, message):
if tool & self.findTools and not messageIsRequest:
response = self.helpers.bytesToString(message.getResponse())
match = self.reFindToken.search(response)
if match and self.token != match.group(1):
self.token = match.group(1)
self.log("New CSRF Token: " + self.token)
### ISessionHandlingAction ###
def getActionName(self):
return "Update CSRF Token"
def performAction(self, currentRequest, macroItems):
request = self.helpers.bytesToString(currentRequest.getRequest())
result = self.reReplaceToken.sub("\\g<1>" + self.token + "\\g<2>", request)
currentRequest.setRequest(result)
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