Using your own domain in AWS Cognito Hosted UI

AWS Cognito can be a great help for any application that doesn’t want to invest in an authorization system. With some basic configuration, one can start creating and managing their own User pool. Cognito also provides a self-hosted domain for hosting an OAuth 2.0 authorization server with built-in webpages that can be used to sign up and sign in users. However, we can use your own domain with below-mentioned steps:

1. Request a certificate in ACM

In AWS Certificate Manager (ACM), request for a certificate with a wildcard domain name (*.yourapp.com). This is done so that your application gets a root domain (yourapp.com) and an auth site (auth.yourapp.com) as well. Choose DNS as the validation method.

2. Validate your certificate

After requesting the certificate, download the DNS Configuration file. Register provided record name in your DNS manager (AWS Route 53) with the record value as CNAME. On success, the certificate status is shown as ‘Issued’.

3. Add the domain in Cognito console

Under App Integration, Domain name section, we can add our domain name and AWS managed certificate. As AWS documentation suggests, the domain is usually the subdomain of your application with ‘auth’ as prefix. Thus, we can use (auth.yourapp.com).

Cognito Console to add domain

4. Register your sub-domain

Again in Route 53, Add a new record set for your subdomain. However, this time, we need to enable alias for the record. In the name, add the subdomain (auth.yourapp.com), enable the alias and add alias target as given in the Cognito console.

Finally, if all goes well the domain status will be ACTIVE and then we will be able to see the login page in our own domain.

Best wishes!