mirror of
https://github.com/mikf/gallery-dl.git
synced 2024-11-22 18:53:21 +01:00
85 lines
2.6 KiB
Python
85 lines
2.6 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
# Copyright 2015, 2016 Mike Fährmann
|
|
#
|
|
# This program is free software; you can redistribute it and/or modify
|
|
# it under the terms of the GNU General Public License version 2 as
|
|
# published by the Free Software Foundation.
|
|
|
|
"""Methods to access sites behind Cloudflare protection"""
|
|
|
|
import time
|
|
import operator
|
|
import urllib.parse
|
|
from . import text
|
|
from .cache import cache
|
|
|
|
def bypass_ddos_protection(session, url):
|
|
"""Prepare a requests.session to access 'url' behind Cloudflare protection"""
|
|
session.cookies = solve_challenge(session, url)
|
|
return session
|
|
|
|
@cache(maxage=24*60*60, keyarg=1)
|
|
def solve_challenge(session, url):
|
|
session.headers["Referer"] = url
|
|
page = session.get(url).text
|
|
params = text.extract_all(page, (
|
|
('jschl_vc', 'name="jschl_vc" value="', '"'),
|
|
('pass' , 'name="pass" value="', '"'),
|
|
))[0]
|
|
params["jschl_answer"] = solve_jschl(url, page)
|
|
time.sleep(4)
|
|
session.get(urllib.parse.urljoin(url, "/cdn-cgi/l/chk_jschl"), params=params)
|
|
return session.cookies
|
|
|
|
def solve_jschl(url, page):
|
|
"""Solve challenge to get 'jschl_answer' value"""
|
|
data, pos = text.extract_all(page, (
|
|
('var' , ',f, ', '='),
|
|
('key' , '"', '"'),
|
|
('expr', ':', '}')
|
|
))
|
|
solution = evaluate_expression(data["expr"])
|
|
variable = "{}.{}".format(data["var"], data["key"])
|
|
vlength = len(variable)
|
|
expressions = text.extract(page, "'challenge-form');", "f.submit();", pos)[0]
|
|
for expr in expressions.split(";")[1:]:
|
|
if expr.startswith(variable):
|
|
func = operator_functions[expr[vlength]]
|
|
value = evaluate_expression(expr[vlength+2:])
|
|
solution = func(solution, value)
|
|
elif expr.startswith("a.value"):
|
|
return solution + len(urllib.parse.urlparse(url).netloc)
|
|
|
|
def evaluate_expression(expr):
|
|
"""Evaluate a Javascript expression for the challange and return its value"""
|
|
stack = []
|
|
ranges = []
|
|
value = ""
|
|
for index, char in enumerate(expr):
|
|
if char == "(":
|
|
stack.append(index+1)
|
|
elif char == ")":
|
|
begin = stack.pop()
|
|
if stack:
|
|
ranges.append((begin, index))
|
|
for subexpr in [expr[begin:end] for begin, end in ranges] or (expr,):
|
|
num = 0
|
|
for part in subexpr.split("[]"):
|
|
num += expression_values[part]
|
|
value += str(num)
|
|
return int(value)
|
|
|
|
operator_functions = {
|
|
"+": operator.add,
|
|
"-": operator.sub,
|
|
"*": operator.mul,
|
|
}
|
|
|
|
expression_values = {
|
|
"": 0,
|
|
"+": 0,
|
|
"!+": 1,
|
|
"+!!": 1,
|
|
}
|