This plugin is used to authenticate in Redmine through an OAuth provider.

The user is identified by the email registered by the OAuth provider. The email must correspond with an email registered in Redmine. If such an email is not found, the user is ofered with registration to Redmine depending on the Redmine's setting Self-registration.

Inspired by Gucin's plugin https://github.com/Gucin/redmine_omniauth_azure.

Supported OAuth providers:

• Azure AD (https://azure.microsoft.com)
• Custom (OpenID Connect - OIDC)
• GitLab (https://about.gitlab.com)
• Google (https://google.com)
• Keycloak (https://www.keycloak.org)
• Otka (https://www.okta.com)

1. Enter the plugins folder
2. Clone the repository
3. Set user permissions
4. Install required gems
5. Restart the application

E.g. Linux + Apache web server

cd plugins
git clone https://github.com/kontron/redmine_oauth.git
chown -R www-data:www-data redmine_oauth
cd ..
bundle install
systemctl restart apache2

Register your Redmine instance as an application by your OAuth provider. Follow the instructions given on their web sites. As the redirect URI add https://yourdomain/oauth2callback.

Open Administration -> Plugins in your Redmine and configure the plugin.

Examples:

• Site: https://login.microsoftonline.com
• Client ID: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
• Client secret: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
• Tenant ID / Realm xxxxxxxx-xxx-xxxx-xxxx-xxxxxxxxxxxx

• Site: https://accounts.google.com
• Client ID: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
• Client secret: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Create a new OIDC Client in your Keycloak Realm. Activate Client authentication.

• Site: https://keycloak.example.com (without any paths)
• Client-ID: keycloak.example.com (do not include https:// or other special characters in the Client ID)
• Secret: Copy the client secret from Keycloak
• Tenant ID: the name of your Keycloak realm

Read emails from an IMAP server and process them into Redmine.

Available options:

• host - IMAP server [outlook.office365.com]
• port - Port [993]
• scope - Scope ['https://outlook.office365.com/.default']
• grant_type - Grant type ['client_credentials']
• ssl - use SSL [Yes]
• starttls - Start TLS [No]
• username - Login
• folder - Mail folder to scan [INBOX]
• move_on_success - Where to move successfully processed messages
• move_on_failure - Where to move unsuccessfully processed messages

Example:

rake redmine_oauth:email:receive_imap username='notifications@example.com' RAILS_ENV="production"

Prior accessing IMAP via OAuth, it is necessary to grant flow to authenticate IMAP connections.

Here is a procedure how to do that in Azure:

https://learn.microsoft.com/en-us/exchange/client-developer/legacy-protocols/how-to-authenticate-an-imap-pop-smtp-application-by-using-oauth#use-client-credentials-grant-flow-to-authenticate-imap-and-pop-connections

cd plugins
rm redmine_oauth

Then restart the application/web server.