@slider-captcha

Generate a puzzle slider captcha and display with React component.

Installation

React frontend:

npm i @slider-captcha/react

Backend:

npm i @slider-captcha/core

Usage

React:

import SliderCaptcha from '@slider-captcha/react';

function verifiedCallback(token) {
  console.log('Captcha token: ' + token);
}

function App() {
  return (
    <SliderCaptcha
      create="https://example.com/captcha/create"
      verify="https://example.com/captcha/verify"
      callback={verifiedCallback}
    />
  );
}

Express:

var sliderCaptcha = require('@slider-captcha/core');

app.get('/captcha/create', function (req, res) {
  sliderCaptcha.create()
    .then(function ({data, solution}) {
      req.session.captcha = solution;
      req.session.save();
      res.status(200).send(data);
    });
});

app.post('/captcha/verify', function (req, res) {
  sliderCaptcha.verify(req.session.captcha, req.body)
    .then(function (verification) {
      if (verification.result === 'success') {
        req.session.token = verification.token;
        req.session.save();
      }
      res.status(200).send(verification);
    });
});

React component props

| Name | Type | Default | Description | |:---- | ---- | ---- | ------ | | callback | func | (token) => console.log(token) | Called with token on successful verification | | create | string or func | captcha/create | Either the URL to fetch data from or a function () returning a promise which resolves with { background, slider } as PNG buffers | | verify | string or func | captcha/verify | Either the URL to fetch data from or a function (response, trail) returning a promise which resolves with { result, token } | | text | { anchor: string, challenge: string } | { anchor: 'I am human', challenge: 'Slide to finish the puzzle' } | Text used for captcha | | variant | string | light | Use 'light' for light theme, 'dark' for dark theme |

Light:

Dark:

Create captcha options

sliderCaptcha.create({option: value})

| Name | Type | Default | Description | |:---- | ---- | ---- | ------ | | image | buffer | randomly generated pattern | Background image used for captcha - resized to 250x150 | | fill | string | #000 | Color used in overlay of puzzle piece on background | | stroke | string | #fff | Color for outline of puzzle piece | | strokeWidth | string | 0.4 | Puzzle piece outline width | | opacity | string | 0.5 | Opacity of puzzle piece overlay on background | | distort | bool | false | Apply distortion to the puzzle piece | | rotate | bool | false | Apply a random rotation to the puzzle piece |

With rotation and distortion:

Verify captcha options

sliderCaptcha.verify(captcha, {response, trail: {x, y}}, {option: value})

| Name | Type | Default | Description | |:---- | ---- | ---- | ------ | | tolerance | number | 7 | Allowed deviation from true captcha value |