Cognito@Edge
Cognito authentication made easy to protect your website with CloudFront and Lambda@Edge.
This Node.js package helps you verify that users making requests to a CloudFront distribution are authenticated using a Cognito user pool. It achieves that by looking at the cookies included in the request and, if the requester is not authenticated, it will redirect then to the user pool's login page.
Alternatives
This package allows you to easily parse and verify Cognito cookies in a Lambda@Edge function. If you want full control over the configuration of AWS resources (CloudFront, Cognito, Lambda@Edge...), this is the solution for you.
If you want to try it out easily or to quickstart a new project, we recommend having a look at the cognito-at-edge-federated-ui-sample repository. It allows you to configure and deploy a sample application which uses Cognito@Edge in a few CLI commands.
If you need more configuration options (e.g. bring your own user pool or CloudFront distribution), you may want to use this Serverless Application Repository application (GitHub) which provides a complete Auth@Edge solution. It does not use Cognito@Edge, but provides similar functionality.
Getting started
How To Install
The preferred way to install the AWS cognito-at-edge for Node.js is to use the npm package manager for Node.js. Simply type the following into a terminal window:
npm install cognito-at-edge
Usage
To use the package, you must create a Lambda@Edge function and associate it with the CloudFront distribution's viewer request events.
Within your Lambda@Edge function, you can import and use the Authenticator
class as shown here:
const { Authenticator } = require('cognito-at-edge');
const authenticator = new Authenticator({
region: 'us-east-1',
userPoolId: 'us-east-1_tyo1a1FHH',
userPoolAppId: '63gcbm2jmskokurt5ku9fhejc6',
userPoolDomain: 'domain.auth.us-east-1.amazoncognito.com',
});
exports.handler = async (request) => authenticator.handle(request);
For an explanation of the interactions between CloudFront, Cognito and Lambda@Edge, we recommend reading this AWS blog article which describe the required architecture to authenticate requests in CloudFront with Cognito.
Reference - Authenticator Class
Authenticator(params)
params
Object Authenticator parameters:
region
string Cognito UserPool region (eg: us-east-1
)userPoolId
string Cognito UserPool ID (eg: us-east-1_tyo1a1FHH
)userPoolAppId
string Cognito UserPool Application ID (eg: 63gcbm2jmskokurt5ku9fhejc6
)userPoolAppSecret
string (Optional) Cognito UserPool Application Secret (eg: oh470px2i0uvy4i2ha6sju0vxe4ata9ol3m63ufhs2t8yytwjn7p
)userPoolDomain
string Cognito UserPool domain (eg: your-domain.auth.us-east-1.amazoncognito.com
)cookieExpirationDays
number (Optional) Number of day to set cookies expiration date, default to 365 days (eg: 365
). It's recommended to set this value to match refreshTokenValidity
parameter of the pool client.disableCookieDomain
boolean (Optional) Sets domain attribute in cookies, defaults to false (eg: false
)httpOnly
boolean (Optional) Forbids JavaScript from accessing the cookies, defaults to false (eg: false
). Note, if this is set to true
, the cookies will not be accessible to Amplify auth if you are using it client side.sameSite
Strict | Lax | None (Optional) Allows you to declare if your cookie should be restricted to a first-party or same-site context (eg: SameSite=None
).parseAuthPath
string (Optional) URI path used as redirect target after successful Cognito authentication (eg: /oauth2/idpresponse
), defaults to the web domain root. Needs to be a path that is handled by the library. When using this parameter, you should also provide a value for cookiePath
to ensure your cookies are available for the right paths.cookiePath
string (Optional) Sets Path attribute in cookiescookieDomain
string (Optional) Sets the domain name used for the token cookiescookieSettingsOverrides
object (Optional) Cookie settings overrides for different token cookies -- idToken, accessToken and refreshToken
idToken
CookieSettings (Optional) Setting overrides to use for idToken
expirationDays
number (Optional) Number of day to set cookies expiration date, default to 365 days (eg: 365
). It's recommended to set this value to match refreshTokenValidity
parameter of the pool client.path
string (Optional) Sets Path attribute in cookieshttpOnly
boolean (Optional) Forbids JavaScript from accessing the cookies, defaults to false (eg: false
). Note, if this is set to true
, the cookies will not be accessible to Amplify auth if you are using it client side.sameSite
Strict | Lax | None (Optional) Allows you to declare if your cookie should be restricted to a first-party or same-site context (eg: SameSite=None
).
accessToken
CookieSettings (Optional) Setting overrides to use for accessTokenrefreshToken
CookieSettings (Optional) Setting overrides to use for refreshToken
logoutConfiguration
object (Optional) Enables logout functionality
logoutUri
string URI path, which when matched with request, logs user out by revoking tokens and clearing cookieslogoutRedirectUri
string The URI to which the user is redirected to after logging them out
csrfProtection
object (Optional) Enables CSRF protection
nonceSigningSecret
string Secret used for signing nonce cookies
logLevel
string (Optional) Logging level. Default: 'silent'
. One of 'fatal'
, 'error'
, 'warn'
, 'info'
, 'debug'
, 'trace'
or 'silent'
.
This is the class constructor.
handle(request)
request
Object Lambda@Edge request object
Use it as your Lambda Handler. It will authenticate each query.
const authenticator = new Authenticator( ... );
exports.handler = async (request) => authenticator.handle(request);
Authentication Gateway Setup
This library can also be used in an authentication gateway setup. If you have a frontend client application that uses AWS Cognito for authentication, it fetches and stores authentication tokens in the browser. Depending on where the tokens are stored in the browser (localStorage, cookies, sessionStorage), they may susceptible to token theft and XSS (Cross-Site Scripting). In order to mitigate this risk, a set of Lambda@Edge handlers can be deployed on a CloudFront distribution which act as an authentication gateway intermediary between the frontend app and Cognito. These handlers will authenticate and fetch tokens on the frontend's behalf and set them as Secure; HttpOnly tokens inside the browser, thereby restricting access to other scripts in the app.
Handlers
handleSignIn
(Can be mapped to /signIn
in Cloudfront setup): Redirect users to Cognito's authorize endpoint after replacing redirect uri with its own -- for instance, /parseAuth
.handleParseAuth
(Can be mapped to /parseAuth
): Exchange Cognito's OAuth code for tokens. Store tokens in browser as HttpOnly cookieshandleRefreshToken
(Can be mapped to /refreshToken
): Refresh idToken and accessToken using refreshTokenhandleSignOut
(Can be mapped to /signOut
): Revoke tokens, clear cookies and redirect user to the URL supplied
const authenticator = new Authenticator( ... );
exports.handler = async (request) => authenticator.handleSignIn(request);
Getting Help
The best way to interact with our team is through GitHub. You can open an issue
and choose from one of our templates for bug reports,
feature requests or
question.
Contributing
We welcome community contributions and pull requests. See CONTRIBUTING.md for information on how to set up a development environment and submit code.
License
This project is licensed under the Apache License, Version 2.0, see LICENSE.txt and NOTICE.txt for more information.