Really Simple CAPTCHA

설명

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

Note: Below are instructions for plugin developers.

First, create an instance of ReallySimpleCaptcha class:

$captcha_instance = new ReallySimpleCaptcha();

You can change the instance variables as you wish.

// Change the background color of CAPTCHA image to black
$captcha_instance->bg = array( 0, 0, 0 );

See really-simple-captcha.php if you are interested in other variables.

Generate a random word for CAPTCHA.

$word = $captcha_instance->generate_random_word();

Generate an image file and a corresponding text file in the temporary directory.

$prefix = mt_rand();
$captcha_instance->generate_image( $prefix, $word );

Then, show the image and get an answer from respondent.

Check the correctness of the answer.

$correct = $captcha_instance->check( $prefix, $the_answer_from_respondent );

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.

$captcha_instance->remove( $prefix );

That’s all.

If you wish to see a live sample of this, you can try Contact Form 7.

스크린샷

  • screenshot-1.png

설치

In most cases you can install automatically from WordPress.

However, if you install this manually, follow these steps:

  1. Upload the entire really-simple-captcha folder to the /wp-content/plugins/ directory.
  2. Activate the plugin through the ‘Plugins’ menu in WordPress.

FYI: There is no “control panel” for this plugin.

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.

If you have any further questions, please submit them to the support forum.

후기

2023년 10월 25일
Helo, very simple banner for cookies but there is a little bug. The banner Cookies are shown in Widgets page.
2021년 12월 17일
Needed this for an installation with custom forms. I used the plugin developers instructions and was able to make a fully custom implementation based on server side validation within 30 minutes. No more spam bots misusing the forms. Thank you!
2021년 1월 21일
Worked great for me a a simple solution to annoying emails. looked good
모든 126 평가 읽기

기여자 & 개발자

“Really Simple CAPTCHA”(은)는 오픈 소스 소프트웨어입니다. 다음의 사람들이 이 플러그인에 기여하였습니다.

기여자

“Really Simple CAPTCHA”(이)가 39(으)로 번역되었습니다. 기여해 주셔서 번역자님께 감사드립니다.

자국어로 “Really Simple CAPTCHA”(을)를 번역하세요.

개발에 관심이 있으십니까?

코드 탐색하기는, SVN 저장소를 확인하시거나, 개발 기록RSS로 구독하세요.

변경이력

2.2

  • Bumps up the minimum required WordPress version to 6.1.
  • Bumps up the minimum required PHP version to 7.4.
  • Replaces ReallySimpleCaptcha::normalize_path() with wp_normalize_path().
  • Updates Apache directives.

2.1

  • Uses hash_equals() to compare strings.