REST API Authentication using Keycloak as OAuth Provider

REST API Authentication plugin will let you authenticate any application (Jira, Confluence, Bitbucket) APIs using any third-party OAuth/OIDC provider or API Tokens. The app supports Azure AD, Keycloak, Okta, AWS Cognito, Google, Github, Slack, Gitlab, Facebook, and any custom provider

Step 1: Configure Keycloak server:

• In your Keycloak admin console, select the realm that you want to use.
• Go to Clients in the left navigation bar and click on  Create.

• Enter the ClientID and select the client protocol as OpenID-connect and click on Save.

• Select access type as Confidential,  enter the redirect URL and click on save (Enter the Application's Base URL).
• To get Client Secret Navigate to Clients, select Client Id and navigate to the Credentials tab.

Note: Copy the ClientID and Client Secret.

Step 2: Fetch Access token through POSTMAN:

• Open the Postman Application (Here is the link to download Postman Application).
• Go to Authorization tab.
• From the dropdown select type as OAuth 2.0 and  click on Get access token.
• Add the following information from the table below.
• Postman starts the authentication flow and prompts you to use the access token.
• Select Add token to the header.

Field	Value
Grant type	Authorization Code or Client Credentials
Callback URL	Enter the Application's base URL if you dont have a callback URL
Auth URL	http://{host_name}/auth/realms/{realm_name}/protocol/openid-connect/auth
Access token URL	http://{host_name}/auth/realms/{realm_name}/protocol/openid-connect/token
Client ID	Enter the Keycloak Client ID
Client secret	Enter the Keycloak  Client secret
Scope	openid
Client Authentication	Send as Basic Auth Header

Note: For Host_name and Realm_name enter the Keycloak hostname and realmname.   

• Copy the Access Token or click on Use Token.

A sample access token from Keycloak Provider looks like this.

A834c0606ba71336423013699db8e971

Step 3: Fetch Username through Keycloak:

• Choose the method type as "GET".
• Enter the interoception Endpoint from the plugin to fetch the username in the Request URL. For Keycloak it is " http://{host_name}/auth/realms/{realm_name}/protocol/openid-connect/userinfo".
• Go to the Authorization tab select the Bearer Token and enter the access token here.
• Add the header "content-type: application/json" and click on Send.

Request:

     curl 
     -X GET 
     -H "Authorization: Bearer <Access Token>" 
     -H "Content-type: application/json" 
     http://{hostname}/auth/realms/{realm_name}/protocol/openid-connect/userinfo