Merge pull request #192 from FormidableLabs/docs-for-amazoncognito

Add docs for AWS cognito

Author: kadikraman

README.md

@@ -31,6 +31,7 @@ These providers are OpenID compliant, which means you can use [autodiscovery](ht
 * [Okta](https://developer.okta.com) ([Example configuration](#okta))
 * [Keycloak](http://www.keycloak.org/) ([Example configuration](#keycloak))
 * [Azure Active Directory](https://docs.microsoft.com/en-us/azure/active-directory) ([Example configuration](#azure-active-directory))
+* [AWS Cognito](https://eu-west-1.console.aws.amazon.com/cognito) ([Example configuration](#aws-cognito))
 
 ### Tested OAuth2 providers:
 
@@ -673,6 +674,44 @@ await revoke(config, {
 });
 ```
 
+### AWS Cognito
+
+First, set up a your user pool in [the AWS console](https://eu-west-1.console.aws.amazon.com/cognito). In the details of your new user pool, go down to `App clients` to create a new client. Make sure you create a client **without** a client secret (it's redundant on mobile). You should get an alphanumeric string which is your `<CLIENT_ID>`.
+
+Now you need to set up your domain name. This will be on the left menu in your pool details page, under App Integration -> Domain Name. What this is depends on your preference. E.g. for AppAuth demo, mine is `https://app-auth-test.auth.eu-west-1.amazoncognito.com` as I chose `app-auth-test` as the domain and `eu-west-1` as the region.
+
+Finally, you need to configure your app client. Go to App Integration -> App Client Settings.
+1. Enable your newly created user pool under Enabled Identity Providers.
+2. Add the callback url (must be same as in your config, e.g. `com.myclientapp://myclient/redirect`)
+3. Enable the Authorization code grant
+4. Enable openid scope
+
+
+```js
+const config = {
+  clientId: '<YOUR_CLIENT_ID>',
+  redirectUrl: 'com.myclientapp://myclient/redirect',
+  serviceConfiguration: {
+    authorizationEndpoint: '<YOUR_DOMAIN_NAME>/oauth2/authorize',
+    tokenEndpoint: '<YOUR_DOMAIN_NAME>/oauth2/token',
+    revocationEndpoint: '<YOUR_DOMAIN_NAME>/oauth2/revoke'
+  }
+};
+
+// Log in to get an authentication token
+const authState = await authorize(config);
+
+// Refresh token
+const refreshedState = await refresh(config, {
+  refreshToken: authState.refreshToken,
+});
+
+// Revoke token
+await revoke(config, {
+  tokenToRevoke: refreshedState.refreshToken
+});
+```
+
 ## Contributors
 
 Thanks goes to these wonderful people