@slider-captcha/core

@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