cloudflare-scrape

A simple Python module to bypass Cloudflare's anti-bot page (also known as "I'm Under Attack Mode", or IUAM), implemented with Requests. Cloudflare changes their techniques periodically, so I will update this repo frequently.

This can be useful if you wish to scrape or crawl a website protected with Cloudflare. Cloudflare's anti-bot page currently just checks if the client supports Javascript, though they may add additional techniques in the future.

Due to Cloudflare continually changing and hardening their protection page, cloudflare-scrape requires Node.js to solve Javascript challenges. This allows the script to easily impersonate a regular web browser without explicitly deobfuscating and parsing Cloudflare's Javascript.

Note: This only works when regular Cloudflare anti-bots is enabled (the "Checking your browser before accessing..." loading page). If there is a reCAPTCHA challenge, you're out of luck. Thankfully, the Javascript check page is much more common.

For reference, this is the default message Cloudflare uses for these sorts of pages:

Checking your browser before accessing website.com.

This process is automatic. Your browser will redirect to your requested content shortly.

Please allow up to 5 seconds...

Any script using cloudflare-scrape will sleep for 5 seconds for the first visit to any site with Cloudflare anti-bots enabled, though no delay will occur after the first request.

Warning

Due to a critical security vulnerability, if you are running version 1.6.6 - 1.7.1, please upgrade to version 1.8.0 immediately. Versions between 1.6.6 and 1.7.1 used a library called Js2Py, which is unsafe to run on untrusted input. If you are running a vulnerable version, a malicious website owner could craft a page which executes arbitrary Python code on the machine that runs this script. This can only occur if the website that the user attempts to scrape has specifically prepared a page to exploit vulnerable versions of cfscrape.

(The following warning applies to version 1.8.0 and onward - including the current version.)

This script will execute arbitrary Javascript code, which can potentially be harmful. Node is the only Javascript engine permitted because it has code sandboxing functionality. All code executed in Node's sandbox cannot access Node's standard library or any Python functions.

Barring a critical flaw in Node, the primary risk is a maliciously crafted page which causes the Javascript interpreter to loop endlessly, or potentially consume a lot of memory.

Shell execution should be impossible unless a severe flaw is discovered in Node or its sandboxing module.

Installation

Simply run pip install cfscrape. The PyPI package is at https://pypi.python.org/pypi/cfscrape/

Alternatively, clone this repository and run python setup.py install.

Dependencies

Python 2.6 - 3.x
Requests >= 2.0
PyExecJS
Node.js is required for (safe) Javascript execution.
- Your computer or server may already have it (check with node -v). If not, you can install it with apt-get install nodejs on Ubuntu and Debian. Otherwise, please read Node's installation instructions.

python setup.py install will install the Python dependencies automatically. Node is the only application you need to install yourself.

Updates

Cloudflare modifies their anti-bot protection page occasionally. So far it has changed maybe once per year on average.

If you notice that the anti-bot page has changed, or if this module suddenly stops working, please create a GitHub issue so that I can update the code accordingly.

In your issue, please include:

The full exception and stack trace.
The URL of the Cloudflare-protected page which the script does not work on.
A Pastebin or Gist containing the HTML source of the protected page.

This issue comment is a good example.

Usage

The simplest way to use cloudflare-scrape is by calling create_scraper().

import cfscrape

scraper = cfscrape.create_scraper()  # returns a CloudflareScraper instance
# Or: scraper = cfscrape.CloudflareScraper()  # CloudflareScraper inherits from requests.Session
print scraper.get("http://somesite.com").content  # => "<!DOCTYPE html><html><head>..."

That's it. Any requests made from this session object to websites protected by Cloudflare anti-bot will be handled automatically. Websites not using Cloudflare will be treated normally. You don't need to configure or call anything further, and you can effectively treat all websites as if they're not protected with anything.

You use cloudflare-scrape exactly the same way you use Requests. (CloudflareScraper works identically to a Requests Session object.) Just instead of calling requests.get() or requests.post(), you call scraper.get() or scraper.post(). Consult Requests' documentation for more information.

Options

Existing session

If you already have an existing Requests session, you can pass it to create_scraper() to continue using that session.

session = requests.session()
session.headers = ...
scraper = cfscrape.create_scraper(sess=session)

Unfortunately, not all of Requests' session attributes are easily transferable, so if you run into problems with this, you should replace your initial sess = requests.session() call with sess = cfscrape.create_scraper().

Integration

It's easy to integrate cloudflare-scrape with other applications and tools. Cloudflare uses two cookies as tokens: one to verify you made it past their challenge page and one to track your session. To bypass the challenge page, simply include both of these cookies (with the appropriate user-agent) in all HTTP requests you make.

To retrieve just the cookies (as a dictionary), use cfscrape.get_tokens(). To retrieve them as a full Cookie HTTP header, use cfscrape.get_cookie_string().

get_tokens and get_cookie_string both accept Requests' usual keyword arguments (like get_tokens(url, proxies={"http": "socks5://localhost:9050"})). Please read Requests' documentation on request arguments for more information.

User-Agent Handling

The two integration functions return a tuple of (cookie, user_agent_string). You must use the same user-agent string for obtaining tokens and for making requests with those tokens, otherwise Cloudflare will flag you as a bot. That means you have to pass the returned user_agent_string to whatever script, tool, or service you are passing the tokens to (e.g. curl, or a specialized scraping tool), and it must use that passed user-agent when it makes HTTP requests.

If your tool already has a particular user-agent configured, you can make cloudflare-scrape use it with cfscrape.get_tokens("http://somesite.com/", user_agent="User-Agent Here") (also works for get_cookie_string). Otherwise, a user-agent spoofing Firefox on Linux will be chosen by default.

Integration examples

Remember, you must always use the same user-agent when retrieving or using these cookies. These functions all return a tuple of (cookie_dict, user_agent_string).

Retrieving a cookie dict through a proxy

get_tokens is a convenience function for returning a Python dict containing Cloudflare's session cookies. For demonstration, we will configure this request to use a proxy. (Please note that if you request Cloudflare clearance tokens through a proxy, you must always use the same proxy when those tokens are passed to the server. Cloudflare requires that the challenge-solving IP and the visitor IP stay the same.)

If you do not wish to use a proxy, just don't pass the proxies keyword argument. Note that these convenience functions support all of Requests' normal keyword arguments.

import cfscrape

proxies = {"http": "http://localhost:8080", "https": "http://localhost:8080"}
tokens, user_agent = cfscrape.get_tokens("http://somesite.com", proxies=proxies)
print tokens
# => {'cf_clearance': 'c8f913c707b818b47aa328d81cab57c349b1eee5-1426733163-3600', '__cfduid': 'dd8ec03dfdbcb8c2ea63e920f1335c1001426733158'}

Retrieving a cookie string

get_cookie_string is a convenience function for returning the tokens as a string for use as a Cookie HTTP header value.

This is useful when crafting an HTTP request manually, or working with an external application or library that passes on raw cookie headers.

import cfscrape
request = "GET / HTTP/1.1\r\n"

cookie_value, user_agent = cfscrape.get_cookie_string("http://somesite.com")
request += "Cookie: %s\r\nUser-Agent: %s\r\n" % (cookie_value, user_agent)

print request

# GET / HTTP/1.1\r\n
# Cookie: cf_clearance=c8f913c707b818b47aa328d81cab57c349b1eee5-1426733163-3600; __cfduid=dd8ec03dfdbcb8c2ea63e920f1335c1001426733158
# User-Agent: Some/User-Agent String

curl example

Here is an example of integrating cloudflare-scrape with curl. As you can see, all you have to do is pass the cookies and user-agent to curl.

import subprocess
import cfscrape

# With get_tokens() cookie dict:

# tokens, user_agent = cfscrape.get_tokens("http://somesite.com")
# cookie_arg = "cf_clearance=%s; __cfduid=%s" % (tokens["cf_clearance"], tokens["__cfduid"])

# With get_cookie_string() cookie header; recommended for curl and similar external applications:

cookie_arg, user_agent = cfscrape.get_cookie_string("http://somesite.com")

# With a custom user-agent string you can optionally provide:

# ua = "Scraping Bot"
# cookie_arg, user_agent = cfscrape.get_cookie_string("http://somesite.com", user_agent=ua)

result = subprocess.check_output(["curl", "--cookie", cookie_arg, "-A", user_agent, "http://somesite.com"])

Trimmed down version. Prints page contents of any site protected with Cloudflare, via curl. (Warning: shell=True can be dangerous to use with subprocess in real code.)

url = "http://somesite.com"
cookie_arg, user_agent = cfscrape.get_cookie_string(url)
cmd = "curl --cookie {cookie_arg} -A {user_agent} {url}"
print(subprocess.check_output(cmd.format(cookie_arg=cookie_arg, user_agent=user_agent, url=url), shell=True))

Donations

This is a very simple and small library that just about anyone could make, but if you are interested in donating to support my efforts, you can donate Bitcoin to:

1FDQDWLdYDxTnuJzKL6bDqJ5KYT7yqvBVH

All donations are unnecessary and not expected, but greatly appreciated.

zhkrb/cloudflare-scrape