IAM

For IAM, OpenStack uses the Keystone project. Keystoneprovides the identity, token, catalog, and policy services, which are used specifically by OpenStack services. It is organized as a group of internal services exposed on one or many endpoints. For example, an authentication call validates the user and project credentials with the identity service.

Authentication

Authentication is an integral part of an OpenStack deployment and so we must be careful about the system design. 

Authentication is the process of confirming a user's identity, which means that a user is actually who they claim to be. For example, providing a username and a password when logging into a system.

Keystone supports authentication using the username and password, LDAP, and external authentication methods. After successful authentication, the identity service provides the user with an authorization token, which is further used for subsequent service requests. Transport Layer Security (TLS) provides authentication between...