How to fix my regex expression (extract value)?-CodePudding

Given the following:

<input type="hidden" id="CSRFToken" name="CSRFToken" value="DFPYWYdMcvDWSmYSHh k5ptFLu068s4/AA=="/>

I want to extract: DFPYWYdMcvDWSmYSHh k5ptFLu068s4/AA=="/

My regex expression is:

 (?i)name *= *([\'\"])\w*csrf\w*\1 *value *= *(\w*) *>

The problem is \w stop at first non char or number, how can I change that? I want to read everything until \1 is seen with extra condition that \ doesn't appear before it.

ie given:

<input type="hidden" id="CSRFToken" name="CSRFToken" value="DFPYWYdMcvDWSmYSHh k5ptFLu068\"s4/AA=="/>

I want to get:

DFPYWYdMcvDWSmYSHh k5ptFLu068\"s4/AA==

Plus given:

I want to get:

ABC

Please Note, in case value is wrapped between " then I want them removed.

CodePudding user response：

.*CSRFToken.*value=["|'](.*)["|']\/> but value must be enclosed by quotes (single or double). It does not make sense that there is a unescaped quote in the string..

.*CSRFToken.*value=(.*)\/> for no quotes around but inside string.

But if that is really working for you to have unescaped quotes, for regex it's ok: .*CSRFToken.*value=(?'quote'["'])?(.*)(?(quote)["'])\/>

This is:

capturing a quote after equals to or not and stores to quote capture group
capturing everything in between to capture group for your further usage
if quote captured anything it will capture "/> or '/> in the end, if not same without quote (maybe last character is a quote in payload string..)

shown here: https://regex101.com/r/qYVBNV/1 but don't know python re syntax for that construct..

CodePudding user response：

I would do something like this in python:

import re

regex = r"name=([\'\"])\w*\1 value=\1(.*)\1.*>"

test_str = ("<input type=\"hidden\" id=\"CSRFToken\" name=\"CSRFToken\" value=\"DFPYWYdMcvDWSmYSHh k5ptFLu068s4/AA==\"/>\n"
    "<input type=\"hidden\" id=\"CSRFToken\" name=\"CSRFToken\" value=\"DFPYWYdMcvDWSmYSHh k5ptFLu068\\\"s4/AA==\"/>\n")

matches = re.finditer(regex, test_str, re.MULTILINE | re.IGNORECASE)

for match in matches:
    print(match.group(2))

\w won't be enough to match what you want to extract so I'm going with .*

I get whatever there is in value:

DFPYWYdMcvDWSmYSHh k5ptFLu068s4/AA==
DFPYWYdMcvDWSmYSHh k5ptFLu068\"s4/AA==