Review the following key concepts to learn how Identity service helps you login and gain access to Rackspace Cloud services.

User

A user is a digital representation of a person, system, or service that uses Rackspace Cloud services. Users have credentials and can be assigned tokens. They can present this information to the Identity service or other Rackspace
Cloud services to confirm identity and verify permission to access the requested system resources.

Users can also be assigned to a tenant or region so that they inherit a set of access rights and privileges automatically, based on the tenant or region configuration.

In the Rackspace Cloud, users are represented as accounts. The accounts are automatically created with a default user type and role, based on the Identity service system configuration. The user type and role determine the resources and capabilities that are available to the user.

For more information, see Identity Service, admin, and user roles.

Authentication

The act of passing in credentials like username and password, confirming an identity, and returning a token representation of the verified identity.

In the Rackspace Cloud, you authenticate by submitting a POST tokens API request with valid credentials to the Identity service endpoint. Credentials are typically a user name and API key. However, other types of credentials can
be accepted based on service, tenant, or user account configuration.

In response to valid credentials, the service returns an authentication token and a service catalog with information about the Rackspace Cloud resources available for use. In subsequent requests to the Identity service or other
Rackspace Cloud service endpoint, the user includes the authentication token in the request as proof of identity, rights, and privileges to complete the requested operation.

Credentials

Any kind of information that can be used to verify an identity. For the Identity service, credentials include these types of information:

a matching user name and password
a matching user name and API key
a unique token issued to you
secret question and answer
verified cell phone number or email address
a multi-factor authentication passcode issued by the Rackspace Cloud
Identity service

Authentication token

An authentication token is an encrypted string returned by the Identity service when you submit an authentication request with valid credentials. Each time that you submit an API request, you include this authentication token.

Because the token expires after 24 hours, you must generate a new token once each day. The token stores information about a user’s credentials and, optionally, user identity information, as well as a time stamp and a digital signature.

If necessary, administrators and users can invalidate a token before it expires by submitting a Revoke token API request. After a token expires or becomes invalid, the Identity service returns 404 errors until you authenticate again.

The Identity service issues authenticated encrypted tokens (AE). AE tokens are non-persistent tokens that contain encrypted metadata that supplies all the necessary information to determine whether a token is valid. For more information, see the Authenticated Encrypted Tokens article.

Authorization

The act of verifying the capability of an authenticated user, system, or process to perform an action on a set of resources. In the Rackspace Cloud, the Identity service provides centralized authorization to ensure that clients
have appropriate access to information and information processing capabilities based on Identity service roles such as system administrator and user administrator. The Rackspace Cloud also supports Role-based access control
which defines product-specific roles to authorize capabilities at the service-level.

Role

A common security construct for assigning a specific set of access rights and privileges to a user or group of users. Service administrators can create named roles, configure the rights and privileges for each role, and manage the
role without updating Roles can be assigned to users, groups, or tenants automatically based on organization security policy. An administrator can view, manage, and update role configuration and assignments as required. Only Identity service administrators can create new roles.

Identity service supports two types of roles:

Global roles define access and permissions across all Rackspace Cloud services, the administrator or observer roles for example.
Product roles define the functions a user can perform for a particular Rackspace Cloud service.

A user with a specific role inherits the rights and privileges associated with the role. In the Identity service, the authentication token issued to a user includes the list of roles associated with the user. The service configuration determines how user roles are interpreted. For example, a role that grants access to certain resources or capabilities within one service can grant access to completely different resources and capabilities on different service.

Role-based access control (RBAC)

RBAC is method to restrict service access to only authorized users. RBAC allows customers to specify who has access to resources and capabilities within their cloud deployment, based on roles defined by Rackspace. For example, an administrator can use RBAC to manage access to Cloud Servers as well as the permissions to complete operations such as adding and deleting servers after access has been granted.

Tenant

A tenant represents logical groups of users to which resources are assigned. In the Rackspace Cloud, tenants allow service providers to organize computing and storage resources without assigning them to user accounts directly. For
example, Virtual machines (Cloud Servers) and containers (Cloud Files) are assigned to tenants, not to users directly.

Depending on the service provider, a tenant can map to a customer, account, organization, or project. Identity users can be part of more than one tenant, and can have different types of roles defined for each tenant that they’re a
part of. The Identity service allows you to create and delete tenants, and also enable and disable them.

Rackspace Cloud has the following two tenant types:

The Mosso tenant (Mosso account) includes the collection of resources commonly associated with services such as Cloud Servers, Cloud Database, Cloud Load Balancers.
The NAST tenant (NAST account) includes the collection of resources commonly associated with Cloud Files and Cloud Files CDN.

Typically, a service provider determines how tenants are defined and used. The Identity service allows service administrators to create, delete, enable, and disable tenants. Service administrators can also assign users and groups to one or more tenants. Because each tenant can have its own role configuration, user can have different roles, or different rights and privileges for the same role on different tenants.

Domain

A domain establishes an administrative boundary for a customer and a space within the Identity service.

In the Identity service API, the domain resource provides a mechanism to expose administrative activities directly to system users. Specifically, an Identity service administrator can create tenants, users, and groups within a domain and assign roles to users and groups. User administrators that have domain administrator capabilities can view and manage the domain associated with their Rackspace Cloud account.

Service

A service is a logical name for the internal and external capabilities provided by a Rackspace Cloud platform or product component. A service provides one or more endpoints through which users can access resources and perform operations. Examples of Rackspace Cloud services include Identity, Servers, Load Balancers, and Files.

Endpoint

A network accessible address, usually described by a URL, where a service can be accessed.

Various Rackspace Cloud systems can query the Identity service for the service endpoints required to complete processes and operations. Users must know the URL for a service endpoint in order to use the service. An API might offer several regional endpoints for a single API.

The Identity service provides one global endpoint: https://identity.api.rackspacecloud.com. To see supported API versions, browse to the endpoint URL. To use a specific version of the API, append the version number to the global endpoint: https://identity.api.rackspacecloud.com/v2.0/.

To get the URLs for other service endpoints, submit an authentication request with valid credentials to a Identity service endpoint. If authentication is successful, the Identity service returns an authentication token and a service
catalog with information about available services, including the endpoints to access each service.

ℹ️
In the Identity service version 1.1 implementation, an endpoint is known as a baseURL.

Service catalog

Taken as a whole, all the service endpoints defined in Keystone are the service catalog, defining all services available to OpenStack.

The service catalog is the list of all the service endpoints defined in the Identity service that represent all services available in the Rackspace Cloud. When a user authenticates, the authentication response returns a subset of the service catalog that includes only the services and information that the user can access.
Each service listing includes at least one endpoint URL to access the service along with other information relevant to using the service such as region, tenant, and version information.
Typically, the service catalog returned to a System administrator has additional information that might not be visible to User administrators or Account sub-users.

All the services in the catalog are available as long as you have a valid authentication token.

Federated identity management

Federated identity management (FIdM) consists of a set of policies, practices and protocols that can be used to manage authentication and authorization of users, processes, and devices across organizations. The goal of identity federation is to enable users of one domain to securely access data or systems of another domain seamlessly by passing an authentication token that was issued by a trusted Identity Provider. Unlike SSO, which allows users to log in to different domains with the same credentials, federated identity management allows users to authenticate through a trusted Identity provider and gain access to any systems that accept identity information from that provider without providing any additional authentication.