Solved: How do I create and use Fully FOSS, Self-Hosted CAPTCHA for Website

Key Takeaways

• A fully FOSS, self-hosted CAPTCHA is a CAPTCHA solution that is free and open source, self-hosted, and compatible with your website’s technology stack.
• A fully FOSS, self-hosted CAPTCHA can offer privacy, security, customization, and accessibility benefits for your website and your users, compared to other CAPTCHA solutions.
• A fully FOSS, self-hosted CAPTCHA can be created and used by using the Python Flask framework and the captcha library, or other similar tools and resources.

Problem

Not all CAPTCHA solutions are created equal. Some of them may rely on third-party services, such as Google’s reCAPTCHA, that may compromise your website’s privacy and security. Others may be too difficult or inaccessible for your users, resulting in frustration and abandonment.

In this article, we will show you how to create and use a fully free and open source, self-hosted CAPTCHA for your website, using the Python Flask framework and some existing open source projects. By doing so, you will have full control over your CAPTCHA’s appearance, functionality, and data, while ensuring a user-friendly and secure experience for your visitors.

Requirements to Create a Fully FOSS, Self-Hosted CAPTCHA

To create a fully FOSS, self-hosted CAPTCHA for your website, you will need the following tools and resources:

• A web server that can run Python applications, such as Apache, Nginx, or Gunicorn.
• The Python Flask framework, which is a lightweight and easy-to-use web framework for building web applications in Python.
• A CAPTCHA generator library, which is a Python module that can generate CAPTCHA images or audio files on the fly. There are several open source projects that you can use, such as captcha or OpenCaptcha.
• A database or a file system, which is a storage system that can store and retrieve the CAPTCHA tokens and answers. You can use any database or file system that is compatible with your web server and CAPTCHA generator library, such as SQLite, MySQL, MongoDB, or Redis.

Solution: Step to Create a Fully FOSS, Self-Hosted CAPTCHA

The following steps will guide you through the process of creating and using a fully FOSS, self-hosted CAPTCHA for your website, using the Python Flask framework and the captcha library as an example. You can adapt these steps to your own web framework and CAPTCHA generator library of choice.

Step 1: Install the Python Flask framework and the captcha library

To install the Python Flask framework and the captcha library, you can use the pip command, which is a package manager for Python. Open a terminal window and enter the following commands:

pip install Flask
pip install captcha

This will install the Flask framework and the captcha library on your web server, along with their dependencies.

Step 2: Create a Flask application and a CAPTCHA route

To create a Flask application and a CAPTCHA route, you can create a Python file, such as app.py, and write the following code:

from flask import Flask, request, make_response
from captcha.image import ImageCaptcha

app = Flask(__name__)

@app.route('/captcha')
def captcha():
# Generate a random CAPTCHA text
text = '1234' # You can use any logic to generate a random text, such as using the random module
# Create an image CAPTCHA object
image = ImageCaptcha()
# Generate an image CAPTCHA file
data = image.generate(text)
# Create a response object with the image CAPTCHA file and the appropriate headers
response = make_response(data.getvalue())
response.headers['Content-Type'] = 'image/png'
# Set a cookie with the CAPTCHA text
response.set_cookie('captcha', text)
# Return the response object
return response

This code will create a Flask application and a CAPTCHA route that will generate and return an image CAPTCHA file and set a cookie with the CAPTCHA text. You can test this route by running the Flask application and visiting the URL http://localhost:5000/captcha in your browser.

Step 3: Create a web form and a validation route

To create a web form and a validation route, you can create an HTML file, such as index.html, and write the following code:

<html>
<head>
<title>Example CAPTCHA Form</title>
</head>
<body>
<h1>Example CAPTCHA Form</h1>
<form action="/validate" method="POST">
<p>Name: <input type="text" name="name" required></p>
<p>Email: <input type="email" name="email" required></p>
<p>Message: <textarea name="message" required></textarea></p>
<p>CAPTCHA: <input type="text" name="captcha" required></p>
<p><img src="/captcha" alt="CAPTCHA image"></p>
<p><input type="submit" value="Submit"></p>
</form>
</body>
</html>

This code will create a web form that will ask the user to enter their name, email, message, and CAPTCHA text, and submit it to the validation route. The web form will also display the image CAPTCHA generated by the CAPTCHA route. You can test this web form by running the Flask application and visiting the URL http://localhost:5000/index.html in your browser.

To create a validation route, you can modify the app.py file and add the following code:

from flask import Flask, request, make_response, render_template, redirect, flash

app = Flask(__name__)
app.secret_key = 'secret' # You can use any secret key for the flash messages

@app.route('/validate', methods=['POST'])
def validate():
# Get the user input from the web form
name = request.form.get('name')
email = request.form.get('email')
message = request.form.get('message')
captcha = request.form.get('captcha')
# Get the CAPTCHA text from the cookie
cookie = request.cookies.get('captcha')
# Compare the user input and the CAPTCHA text
if captcha == cookie:
# If they match, display a success message
flash('Your message has been sent successfully.')
else:
# If they don't match, display an error message
flash('Invalid CAPTCHA. Please try again.')
# Redirect to the web form
return redirect('/index.html')

This code will create a validation route that will get the user input from the web form and the CAPTCHA text from the cookie, and compare them. If they match, it will display a success message. If they don’t match, it will display an error message. It will then redirect to the web form. You can test this validation route by running the Flask application and submitting the web form with the correct or incorrect CAPTCHA text.

Frequently Asked Questions (FAQs)

Question: What is a Fully FOSS, Self-Hosted CAPTCHA?

Answer: A fully free and open source, self-hosted CAPTCHA is a CAPTCHA solution that meets the following criteria:

• It is free and open source software (FOSS), meaning that you can use, modify, and distribute it without any restrictions or fees.
• It is self-hosted, meaning that you can run it on your own server, without relying on any external services or APIs.
• It is compatible with your website’s technology stack, meaning that you can integrate it with your web framework and language of choice.

Question: Why Do You Need a Fully FOSS, Self-Hosted CAPTCHA?

Answer: There are several benefits of using a fully FOSS, self-hosted CAPTCHA for your website, such as:

• Privacy: You can protect your website’s and your users’ data from being collected or leaked by third-party services, such as Google or Facebook, that may use it for advertising or other purposes.
• Security: You can prevent malicious attacks from bots and spammers that may try to exploit your web forms, such as creating fake accounts, sending spam messages, or posting inappropriate comments.
• Customization: You can customize your CAPTCHA’s appearance, difficulty, and logic to suit your website’s design, theme, and audience.
• Accessibility: You can ensure that your CAPTCHA is accessible to all users, regardless of their language, device, or disability, by providing alternative options, such as audio or text CAPTCHAs.

Question: What are the advantages and disadvantages of using a fully FOSS, self-hosted CAPTCHA?

Answer: Some of the advantages of using a fully FOSS, self-hosted CAPTCHA are:

• You have full control over your CAPTCHA’s appearance, functionality, and data.
• You can protect your website’s and your users’ privacy and security from third-party services.
• You can customize your CAPTCHA to suit your website’s design, theme, and audience.
• You can ensure your CAPTCHA’s accessibility to all users.

Some of the disadvantages of using a fully FOSS, self-hosted CAPTCHA are:

• You need to have some technical skills and resources to create and maintain your CAPTCHA.
• You may need to update your CAPTCHA regularly to keep up with the advances of bots and spammers.
• You may need to test your CAPTCHA’s compatibility and performance across different devices and browsers.

Question: What are some alternatives to using a fully FOSS, self-hosted CAPTCHA?

Answer: Some of the alternatives to using a fully FOSS, self-hosted CAPTCHA are:

• Using a third-party CAPTCHA service, such as Google’s reCAPTCHA, that may offer a more convenient and reliable way to implement a CAPTCHA on your website, but may also pose some privacy and security risks, as they may collect and use your website’s and your users’ data for their own purposes. Some examples of third-party CAPTCHA services are [reCAPTCHA], [hCaptcha], and [Solve Media].

• Using a honeypot technique, which is a hidden field or a checkbox on your web form that is invisible to human users, but visible to bots and spammers. If the hidden field is filled or the checkbox is checked, it means that the submission is from a bot or a spammer, and you can reject it. This technique may be simpler and less intrusive than using a CAPTCHA, but it may also be less effective, as some bots and spammers may be able to bypass it.
• Using a behavioral analysis technique, which is a method of tracking and analyzing the user’s behavior on your website, such as their mouse movements, keystrokes, scrolling, and time spent, to determine if they are human or not. This technique may be more accurate and user-friendly than using a CAPTCHA, but it may also require more computational resources and data processing, as well as raise some ethical and legal issues regarding user consent and privacy.

Summary

In this article, we have shown you how to create and use a fully free and open source, self-hosted CAPTCHA for your website, using the Python Flask framework and the captcha library as an example. By doing so, you can protect your website from bots and spammers, while ensuring your website’s and your users’ privacy and security, as well as your CAPTCHA’s customization and accessibility. We have also discussed some of the advantages and disadvantages of using a fully FOSS, self-hosted CAPTCHA, and some of the alternatives to it. We hope that this article has been helpful and informative for you, and that you have learned something new and useful from it.

Disclaimer: This article is for educational and informational purposes only, and does not constitute any professional or legal advice. The author and the publisher are not responsible for any errors, omissions, or damages that may arise from the use of the information or code provided in this article. The user is solely responsible for verifying the accuracy and suitability of the information and code for their own purposes, and for complying with any applicable laws and regulations. The user is also advised to backup their data and test their code before deploying it on their website. The user is also encouraged to consult a qualified professional or expert before implementing any CAPTCHA solution on their website.