Django Simple Captcha is an extremely simple, yet highly customizable Django application to add captcha images to any Django form. Implementing simple custom captcha in ASP.NET MVC In this article, we shall learn how to implement simple CAPTCHA (that is used to stop automated robots or scripts to submit malicious data) in ASP.NET MVC. Really Simple Captcha is an easy to use WordPress Captcha Plugin. Really Simple Captcha works with Contact Form 7 plugin and creates three different captcha. The general steps to building a simple captcha in PHP are: When the user accesses the page to be secured, start the session and generate a random captcha string. Create the captcha image using the GD extension. Embed the captcha image into the HTML form, challenge the user to enter the captcha string. Learn about all important CSS properties from the basics with our extensive and easy-to-read CSS Reference. It doesn't matter if you are a beginner or intermediate, start learning CSS now.
- Simple Captcha Solver
- Simple Captcha Html
- Simple Captcha Java
- Html Contact Form With Captcha
- Simple Captcha Php
- Simple Captcha Php
Installation¶
- Install
django-simple-captcha
via pip:pipinstalldjango-simple-captcha
- Add
captcha
to theINSTALLED_APPS
in yoursettings.py
- Run
pythonmanage.pymigrate
- Add an entry to your
urls.py
:
Note: Pillow requires that image libraries are installed on your system. On e.g. Debian or Ubuntu, you’d need these packages to compile and install Pillow:
Adding to a Form¶
Using a
CaptchaField
is quite straight-forward:Define the Form¶
To embed a CAPTCHA in your forms, simply add a
CaptchaField
to the form definition:…or, in a
ModelForm
:Validate the Form¶
In your view, validate the form as usual. If the user didn’t provide a valid response to the CAPTCHA challenge, the form will raise a
ValidationError
and display an error message to the user:Passing arguments to the field¶
CaptchaField
takes a few optional arguements:output_format
will let you format the layout of the rendered field. Defaults to the value defined in : CAPTCHA_OUTPUT_FORMAT.id_prefix
Optional prefix that will be added to the ID attribute in the generated fields and labels, to be used when e.g. several Captcha fields are being displayed on a same page. (added in version 0.4.4)generator
Optional callable or module path to callable that will be used to generate the challenge and the response, e.g.generator='path.to.generator_function'
orgenerator=lambda:('LOL','LOL')
, see also Generators and modifiers. Defaults to whatever is defined insettings.CAPTCHA_CHALLENGE_FUNCT
.
Example usage for ajax form¶
An example CAPTCHA validation in AJAX:
And in javascript your must update the image and hidden input in form
Example usage ajax refresh button¶
# html:
# javascript:
Example usage ajax refresh¶
# javascript:
Description
Really Simple CAPTCHA does not work alone and is intended to work with other plugins. It is originally created for Contact Form 7, however, you can use it with your own plugin.
Note: This product is “really simple” as its name suggests, i.e., it is not strongly secure. If you need perfect security, you should try other solutions.
How does it work?
Really Simple CAPTCHA does not use PHP “Sessions” for storing states, unlike many other PHP CAPTCHA solutions, but stores them as temporary files. This allows you to embed it into WordPress without worrying about conflicts.
When you generate a CAPTCHA, Really Simple CAPTCHA creates two files for it; one is an image file of CAPTCHA, and the other is a text file which stores the correct answer to the CAPTCHA.
The two files have the same (random) prefix in their file names, for example, “a7hk3ux8p.png” and “a7hk3ux8p.txt.” In this case, for example, when the respondent answers “K5GF” as an answer to the “a7hk3ux8p.png” image, then Really Simple CAPTCHA calculates hash of “K5GF” and tests it against the hash stored in the “a7hk3ux8p.txt” file. If the two match, the answer is confirmed as correct.
How to use with your plugin
Simple Captcha Solver
Note: Below are instructions for plugin developers.
First, create an instance of ReallySimpleCaptcha class:
Simple Captcha Html
You can change the instance variables as you wish.
See really-simple-captcha.php if you are interested in other variables.
Generate a random word for CAPTCHA.
Generate an image file and a corresponding text file in the temporary directory.
Then, show the image and get an answer from respondent.
Check the correctness of the answer.
If the $correct is true, go ahead. Otherwise, block the respondent — as it would appear not to be human.
And last, remove the temporary image and text files, as they are no longer in use.
Simple Captcha Java
That’s all.
If you wish to see a live sample of this, you can try Contact Form 7.
Installation
In most cases you can install automatically from WordPress.
However, if you install this manually, follow these steps:
- Upload the entire
really-simple-captcha
folder to the/wp-content/plugins/
directory. - Activate the plugin through the ‘Plugins’ menu in WordPress.
FYI: There is no “control panel” for this plugin.
Html Contact Form With Captcha
FAQ
CAPTCHA does not work; the image does not show up.
Really Simple CAPTCHA needs GD and FreeType library installed on your server. Ask your server administrator if they are installed.
Also, make the temporary file folder writable. The location of the temporary file folder is managed by the instance variable
tmp_dir
of ReallySimpleCaptcha class. Note that the setting varies depending on the calling plugin. For example, Contact Form 7 uses wp-contents/uploads/wpcf7_captcha
as the temporary folder basically, but it can use different folder depending on your settings.Simple Captcha Php
If you have any further questions, please submit them to the support forum.
Simple Captcha Php
Reviews
Worked great for me a a simple solution to annoying emails. looked good