tanmaiaccion/redirect-rule.js

## redirect-rule.js
function (user, context, callback) {

  // this rule requires the following configuration values:
  // CAPTCHA_SECRET: a 32 bytes string that will be the shared secret between
  //                 the rule and the webtask
  // AUTH0_DOMAIN: your auth0 domain (e.g. account.auth0.com)
  // CAPTCHA_REDIRECT: the URL for the webtask that will show and process CAPTCHA

  // Put a specific client ID if you dont want CAPTCHA for every client
  // if (context.clientID !== '[your client id]')
  //  return callback(null, user, context);


  var secret = configuration.CAPTCHA_SECRET;
  var ruleUri = 'https://' + configuration.AUTH0_DOMAIN + '/rules/captcha';
  var wtUri = ruleUri + '/wt';

  if (context.protocol !== "redirect-callback") {
    // User has initiated a login and is forced to take a CAPTCHA challenge
    // Send user's information in a JWT to avoid tampering
    var token = jwt.sign({
        sub: user.user_id,
        clientName: context.clientName
      },
      secret,
      {
        expiresInMinutes: 5,
        audience: wtUri,
        issuer: ruleUri
      }
    );
    var redirectUrl = configuration.CAPTCHA_REDIRECT;
    var separator = redirectUrl.indexOf('?') !== -1 ? "&" : "?";
    context.redirect = {
      url: redirectUrl + separator + "token=" + token + "&webtask_no_cache=1"
    };
    return callback(null, user, context);
  } else {
    // User has been redirected to /continue?token=...,
    // captcha action must be validated
    // The generated token must include a `captchaOk` claim to
    // confirm a successful response
    var postVerify = function(err, decoded) {
      if (err) {
        return callback(new UnauthorizedError("Error validating token from wt: " + err));
      } else if (decoded.sub !== user.user_id) {
        return callback(new UnauthorizedError("Token does not match the current user."));
      } else if (!decoded.captchaOk) {
        return callback(new UnauthorizedError("Captcha validation was not successful.\n" +
                                             decoded.errorMessage || ""));
      } else {
        // Captcha ok, go ahead with authentication
        return callback(null, user, context);
      }
    };

    jwt.verify(
      context.request.query.token,
      secret,
      {
        audience: ruleUri,
        issuer: wtUri
      },
      postVerify
    );
  }
}

## webtask.js
'use latest';

// This webtask requires the following configured secrets:

// RECAPTCHA_SITE_KEY     These two values can be obtained from http://www.google.com/recaptcha/admin
// RECAPTCHA_SITE_SECRET
//
// CAPTCHA_SECRET         A 32 byte string that is the shared key between the rule and the webtask
// AUTH0_DOMAIN           Your Auth0 domain (e.g. account.auth0.com)


import { fromExpress } from 'webtask-tools';
const express = require('express@4.14.0');
const bodyParser = require('body-parser@1.12.4');
const app = express();
const url = require('url'); // built-in utility
const jwt = require('jsonwebtoken@5.7.0');
const request = require('request@2.67.0');

app.use(bodyParser.urlencoded()); // for parsing application/x-www-form-urlencoded

var getRuleUri = function(req) { return 'https://' + req.webtaskContext.secrets.AUTH0_DOMAIN + '/rules/captcha'; };
var getWtUri = function(req) { return getRuleUri(req) + '/wt';};

app.get('/', (req, res) => {

  var captchaView = (function view() {/*
<html>
<head>
  <meta charset="utf-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <STYLE type="text/css">
    html {
      font-family: sans-serif;
      -webkit-text-size-adjust: 100%;
          -ms-text-size-adjust: 100%;
    }
    body { margin: 0; }
    .container { padding-right: 15px; padding-left: 15px;margin-right: auto; margin-left: auto; }
    h1 { margin: .67em 0; font-size: 2em; font-family: inherit; font-weight: 500; line-height: 1.1; color: inherit; }
</STYLE>
 <title>Confirm you are human</title>
  <!-- Latest compiled and minified CSS -->
  <script src='https://www.google.com/recaptcha/api.js'></script>
</head>
<body>
  <script type="text/javascript">
    var submitform = function() {
      document.getElementById("captchaform").submit();
    };
  </script>
  <div class="container">
    <form class="form-signin" action="<%= target %>" method="POST" id="captchaform">
      <h1>Complete the log-in process <%= clientName %></h1>
      <input type="hidden" value="<%= state %>" name="state" />
      <input type="hidden" value="<%= token %>" name="token" />
      <div class="g-recaptcha" data-sitekey="<%= sitekey %>" data-callback="submitform"></div>
    </form>
  </div>
</body>
</html>
  */}).toString().match(/[^]*\/\*([^]*)\*\/\s*\}$/)[1];

  var myUri = req.originalUrl.split("?")[0];
  var secrets = req.webtaskContext.secrets;

  jwt.verify(
    req.body.token,
    secrets.CAPTCHA_SECRET, {
      audience: getWtUri(req),
      issuer: getRuleUri(req)
    },
    function(err, tokenPayload) {

      var target = url.parse(req.originalUrl).pathname;

      res.writeHead(200, { 'Content-Type': 'text/html' });
      res.end(require('ejs').render(captchaView, {
          state: req.query.state,
          target: target,
          token: req.query.token,
          sitekey: secrets.RECAPTCHA_SITE_KEY,
          clientName: tokenPayload ? "to " + tokenPayload.clientName : ""
      }));
  });
});

app.post('/', (req, res) => {
  var secrets = req.webtaskContext.secrets;

  var continueToRule = function(err, subject, state) {
    var token = jwt.sign({
          captchaOk: err === null,
          sub: subject,
          errorMessage: err
        },
        secrets.CAPTCHA_SECRET, {
          expiresInMinutes: 2,
          audience: getRuleUri(req),
          issuer: getWtUri(req)
        }
    );
    res.redirect(302, "https://" + secrets.AUTH0_DOMAIN + "/continue?state=" + req.body.state + "&token=" + token);
  }

  var postVerify = function(err, decoded) {
    if (err) {
       continueToRule("Invalid token: " + err, null);
    } else if (!decoded.sub) {
       continueToRule("Token does not contain 'sub' claim.", null);
    } else {
      continueToRule(null, decoded.sub);
    }
  };

  var verifyCaptcha = function(captchaResponse, callback) {
    request.post( {
      url: 'https://www.google.com/recaptcha/api/siteverify',
      form: {
        secret: secrets.RECAPTCHA_SITE_SECRET,
        response: captchaResponse,
        remoteip: req.ip
      }}, function (error, response, body) {
        if (error) {
          callback(error);
        }
        if (response.statusCode !== 200) {
          callback('Error validating captcha: '+ response.statusCode);
        }
        var data = JSON.parse(body);
        if (data.success) {
          callback();
        } else {
          callback("Error from reCaptcha: " + JSON.stringify(data));
        }
      }
    );
  };

  verifyCaptcha(req.body["g-recaptcha-response"], function(err) {
    if (err) {
      continueToRule("Invalid reCAPTCHA validation." + err, null);
      return;
    }
    jwt.verify(req.body.token, secrets.CAPTCHA_SECRET, {
      audience: getWtUri(req),
      issuer: getRuleUri(req)
    }, postVerify);

  });
});

module.exports = fromExpress(app);
	function (user, context, callback) {

	// this rule requires the following configuration values:
	// CAPTCHA_SECRET: a 32 bytes string that will be the shared secret between
	// the rule and the webtask
	// AUTH0_DOMAIN: your auth0 domain (e.g. account.auth0.com)
	// CAPTCHA_REDIRECT: the URL for the webtask that will show and process CAPTCHA

	// Put a specific client ID if you dont want CAPTCHA for every client
	// if (context.clientID !== '[your client id]')
	// return callback(null, user, context);


	var secret = configuration.CAPTCHA_SECRET;
	var ruleUri = 'https://' + configuration.AUTH0_DOMAIN + '/rules/captcha';
	var wtUri = ruleUri + '/wt';

	if (context.protocol !== "redirect-callback") {
	// User has initiated a login and is forced to take a CAPTCHA challenge
	// Send user's information in a JWT to avoid tampering
	var token = jwt.sign({
	sub: user.user_id,
	clientName: context.clientName
	},
	secret,
	{
	expiresInMinutes: 5,
	audience: wtUri,
	issuer: ruleUri
	}
	);
	var redirectUrl = configuration.CAPTCHA_REDIRECT;
	var separator = redirectUrl.indexOf('?') !== -1 ? "&" : "?";
	context.redirect = {
	url: redirectUrl + separator + "token=" + token + "&webtask_no_cache=1"
	};
	return callback(null, user, context);
	} else {
	// User has been redirected to /continue?token=...,
	// captcha action must be validated
	// The generated token must include a `captchaOk` claim to
	// confirm a successful response
	var postVerify = function(err, decoded) {
	if (err) {
	return callback(new UnauthorizedError("Error validating token from wt: " + err));
	} else if (decoded.sub !== user.user_id) {
	return callback(new UnauthorizedError("Token does not match the current user."));
	} else if (!decoded.captchaOk) {
	return callback(new UnauthorizedError("Captcha validation was not successful.\n" +
	decoded.errorMessage \|\| ""));
	} else {
	// Captcha ok, go ahead with authentication
	return callback(null, user, context);
	}
	};

	jwt.verify(
	context.request.query.token,
	secret,
	{
	audience: ruleUri,
	issuer: wtUri
	},
	postVerify
	);
	}
	}
	'use latest';

	// This webtask requires the following configured secrets:

	// RECAPTCHA_SITE_KEY These two values can be obtained from http://www.google.com/recaptcha/admin
	// RECAPTCHA_SITE_SECRET
	//
	// CAPTCHA_SECRET A 32 byte string that is the shared key between the rule and the webtask
	// AUTH0_DOMAIN Your Auth0 domain (e.g. account.auth0.com)


	import { fromExpress } from 'webtask-tools';
	const express = require('express@4.14.0');
	const bodyParser = require('body-parser@1.12.4');
	const app = express();
	const url = require('url'); // built-in utility
	const jwt = require('jsonwebtoken@5.7.0');
	const request = require('request@2.67.0');

	app.use(bodyParser.urlencoded()); // for parsing application/x-www-form-urlencoded

	var getRuleUri = function(req) { return 'https://' + req.webtaskContext.secrets.AUTH0_DOMAIN + '/rules/captcha'; };
	var getWtUri = function(req) { return getRuleUri(req) + '/wt';};

	app.get('/', (req, res) => {

	var captchaView = (function view() {/*
	<html>
	<head>
	<meta charset="utf-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<STYLE type="text/css">
	html {
	font-family: sans-serif;
	-webkit-text-size-adjust: 100%;
	-ms-text-size-adjust: 100%;
	}
	body { margin: 0; }
	.container { padding-right: 15px; padding-left: 15px;margin-right: auto; margin-left: auto; }
	h1 { margin: .67em 0; font-size: 2em; font-family: inherit; font-weight: 500; line-height: 1.1; color: inherit; }
	</STYLE>
	<title>Confirm you are human</title>
	<!-- Latest compiled and minified CSS -->
	<script src='https://www.google.com/recaptcha/api.js'></script>
	</head>
	<body>
	<script type="text/javascript">
	var submitform = function() {
	document.getElementById("captchaform").submit();
	};
	</script>
	<div class="container">
	<form class="form-signin" action="<%= target %>" method="POST" id="captchaform">
	<h1>Complete the log-in process <%= clientName %></h1>
	<input type="hidden" value="<%= state %>" name="state" />
	<input type="hidden" value="<%= token %>" name="token" />
	<div class="g-recaptcha" data-sitekey="<%= sitekey %>" data-callback="submitform"></div>
	</form>
	</div>
	</body>
	</html>
	/}).toString().match(/[^]\/\([^])\\/\s\}$/)[1];

	var myUri = req.originalUrl.split("?")[0];
	var secrets = req.webtaskContext.secrets;

	jwt.verify(
	req.body.token,
	secrets.CAPTCHA_SECRET, {
	audience: getWtUri(req),
	issuer: getRuleUri(req)
	},
	function(err, tokenPayload) {

	var target = url.parse(req.originalUrl).pathname;

	res.writeHead(200, { 'Content-Type': 'text/html' });
	res.end(require('ejs').render(captchaView, {
	state: req.query.state,
	target: target,
	token: req.query.token,
	sitekey: secrets.RECAPTCHA_SITE_KEY,
	clientName: tokenPayload ? "to " + tokenPayload.clientName : ""
	}));
	});
	});

	app.post('/', (req, res) => {
	var secrets = req.webtaskContext.secrets;

	var continueToRule = function(err, subject, state) {
	var token = jwt.sign({
	captchaOk: err === null,
	sub: subject,
	errorMessage: err
	},
	secrets.CAPTCHA_SECRET, {
	expiresInMinutes: 2,
	audience: getRuleUri(req),
	issuer: getWtUri(req)
	}
	);
	res.redirect(302, "https://" + secrets.AUTH0_DOMAIN + "/continue?state=" + req.body.state + "&token=" + token);
	}

	var postVerify = function(err, decoded) {
	if (err) {
	continueToRule("Invalid token: " + err, null);
	} else if (!decoded.sub) {
	continueToRule("Token does not contain 'sub' claim.", null);
	} else {
	continueToRule(null, decoded.sub);
	}
	};

	var verifyCaptcha = function(captchaResponse, callback) {
	request.post( {
	url: 'https://www.google.com/recaptcha/api/siteverify',
	form: {
	secret: secrets.RECAPTCHA_SITE_SECRET,
	response: captchaResponse,
	remoteip: req.ip
	}}, function (error, response, body) {
	if (error) {
	callback(error);
	}
	if (response.statusCode !== 200) {
	callback('Error validating captcha: '+ response.statusCode);
	}
	var data = JSON.parse(body);
	if (data.success) {
	callback();
	} else {
	callback("Error from reCaptcha: " + JSON.stringify(data));
	}
	}
	);
	};

	verifyCaptcha(req.body["g-recaptcha-response"], function(err) {
	if (err) {
	continueToRule("Invalid reCAPTCHA validation." + err, null);
	return;
	}
	jwt.verify(req.body.token, secrets.CAPTCHA_SECRET, {
	audience: getWtUri(req),
	issuer: getRuleUri(req)
	}, postVerify);

	});
	});

	module.exports = fromExpress(app);