Captcheck Easy, light, self-hostable CAPTCHA service. Works on modern browsers (and IE9+). Uses a selection of icons from Font-Awesome. Text-only accessibility mode and support for keyboard-only operation. Thanks to for supplying the data for the text CAPTCHA. How to use ---------- In your form, put an empty div with the class "captcheck_container". Add `captcheck.js` (or `captcheck.dist.js`) into your page. Captcheck Sample Form
When the form is submitted, your server will receive two extra form fields: `captcheck_session_code` and `captcheck_selected_answer`. In your form handling code, send a request to `http(s)://captcheck-url/api.php`. Pass the variables `session_id` and `answer_id` with the values sent with the form, and also pass the variable `action` with the value `verify`. You will receive a JSON response with (among other things) `"result": true` or `"result": false`. If result is false, the user failed the test, and another variable `msg` is available with an explanation. Example URL: `http(s)://captcheck-url/api.php?action=verify&session_id=&answer_id=` Example responses: `{"session":"some_session_id","result":true}` `{"session":"some_session_id","result":false,"msg":"Answer incorrect."}` ###Content-Security-Policy and Nonces Add `data-stylenonce="nonce_here"` to the `.captcheck_container` div. If you have multiple CAPTCHAs on one page, only one of them needs the nonce specified. Installation ------------ 1. Run composer install. 2. Copy settings.template.php to settings.php and plug in your settings. 3. Install the database. 4. Customize captcheck.js with the correct api_url. 5. Follow the How to Use section and the example setup in test.html and test.php. Execution Flow -------------- JS = captcheck.js, API = api.php, FORM = parent form, SITE = form processing code, -> = some action taken on the right by the left JS -> API: Request session ID, question, and answers (with scrambled random codes) API -> JS: Sends info, saves session ID, correct answer, and scrambled answer codes in DB JS -> API: Requests answer images by sending scrambled value and session ID JS -> FORM: Adds hidden field with value=session ID, displays question and images (or text box) [USER SUBMITS FORM] SITE -> API: Sends session ID and answer API -> SITE: Responds with true/false to indicate if the answer is valid, marks session as expired to prevent CAPTCHA reuse