# OpenID Connect Provider

## Presentation

OpenID Connect is a protocol based on REST, OAuth 2.0 and JOSE stacks. It is described here: http://openid.net/connect/.

LL::NG can act as an OpenID Connect Provider (OP). It will answer to OpenID Connect requests to give user identity (trough ID Token) and information (trough User Info end point).

As an OP, LL::NG supports a lot of OpenID Connect features:

- Authorization Code, Implicit and Hybrid flows
- Publication of JSON metadata and JWKS data (Discovery)
- `prompt`, `display`, `ui_locales`, `max_age` parameters
- Extra claims definition
- Authentication context Class References (ACR)
- Nonce
- Dynamic registration
- Access Token Hash generation
- ID Token signature (HS256/HS384/HS512/RS256/RS384/RS512)
- UserInfo endpoint, as JSON or as JWT
- Request and Request URI
- Session management
- FrontChannel Logout
- BackChannel Logout
- PKCE (Since `2.0.4`) - See RFC 7636
- Introspection endpoint (Since `2.0.6`) - See RFC 7662
- Offline access (Since `2.0.7`)
- Refresh Tokens (Since `2.0.7`)

## Configuration

### OpenID Connect Service

See OpenID Connect service configuration chapter.

### IssuerDB

Go in `General Parameters` » `Issuer modules` » `OpenID Connect` and configure:

- Activation: set to `On`.
- Path: keep `^/oauth2/` unless you need to use another path
- Use rule: a rule to allow user to use this module, set to `1` to always allow.

For example, to allow only users with a strong authentication level:

    $authenticationLevel > 2

### Configuration of LL::NG in Relying Party

Each Relying Party has its own configuration way. LL::NG publish its OpenID Connect metadata to ease the configuration of client.

The metadata can be found at the standard "Well Known" URL: http://auth.example.com/.well-known/openid-configuration

An example of its content:

    {
       "end_session_endpoint" : "http://auth.example.com/oauth2/logout",
       "jwks_uri" : "http://auth.example.com/oauth2/jwks",
       "token_endpoint_auth_methods_supported" : [
          "client_secret_post",
          "client_secret_basic"
       ],
       "token_endpoint" : "http://auth.example.com/oauth2/token",
       "response_types_supported" : [
          "code",
          "id_token",
          "id_token token",
          "code id_token",
          "code token",
          "code id_token token"
       ],
       "userinfo_signing_alg_values_supported" : [
          "none",
          "HS256",
          "HS384",
          "HS512",
          "RS256",
          "RS384",
          "RS512"
       ],
       "id_token_signing_alg_values_supported" : [
          "none",
          "HS256",
          "HS384",
          "HS512",
          "RS256",
          "RS384",
          "RS512"
       ],
       "userinfo_endpoint" : "http://auth.example.com/oauth2/userinfo",
       "request_uri_parameter_supported" : "true",
       "acr_values_supported" : [
          "loa-4",
          "loa-1",
          "loa-3",
          "loa-5",
          "loa-2"
       ],
       "request_parameter_supported" : "true",
       "subject_types_supported" : [
          "public"
       ],
       "issuer" : "http://auth.example.com/",
       "grant_types_supported" : [
          "authorization_code",
          "implicit",
          "hybrid"
       ],
       "authorization_endpoint" : "http://auth.example.com/oauth2/authorize",
       "check_session_iframe" : "http://auth.example.com/oauth2/checksession",
       "scopes_supported" : [
          "openid",
          "profile",
          "email",
          "address",
          "phone"
       ],
       "require_request_uri_registration" : "false",
       "registration_endpoint" : "http://auth.example.com/oauth2/register"
    }

### Configuration of Relying Party in LL::NG

Go in Manager and click on `OpenID Connect Relying Parties`, then click on `Add OpenID Relying Party`. Give a technical label (no spaces, no special characters), like “sample-rp”;

You can then access to the configuration of this RP.

#### Exported attributes

You can map here the attribute names from the LL::NG session to an OpenID Connect claim.

Claim name | Associated scope | Type | Example of corresponding LDAP attribute
--- | --- | --- | ---
sub | openid | string | uid
name | profile | string | cn
given_name | profile | string | givenName
family_name | profile | string | sn
middle_name | profile | string |
nickname | profile | string |
preferred_username | profile | string | displayName
profile | profile | string | labeledURI
picture | profile | string |
website | profile | string |
email | email | string | mail
email_verified | email | boolean |
gender | profile | string |
birthdate | profile | string |
zoneinfo | profile | string |
locale | profile | string | preferredLanguage
phone_number | phone | string | telephoneNumber
phone_number_verified | phone | boolean |
updated_at | profile | string |
formatted | address | string | registeredAddress
street_address | address | string | street
locality | address | string | l
region | address | string | st
postal_code | address | string | postalCode
country | address | string | co

So you can define for example:

- name => cn
- family_name => sn
- email => mail

The specific `sub` attribute is not defined here, but in User attribute parameter (see below).

#### Extra Claims

By default, only claims that are part of standard OpenID Connect scopes will be sent to a client. If you want to send a claim that is not in the OpenID Connect specification, you need to declare it in the Extra Claims section

If you want to make custom claims visible to OpenID Connect clients, you need to declare them in a scope.

Add your additional scope as the Key, and a space-separated list of claims as the Value:

- timelord => rebirth_count bloodline

In this example, an OpenID Client asking for the `timelord` scope will be able to read the `rebirth_count` and `bloodline` claims from the Userinfo endpoint.

Any Claim defined in this section must be mapped to a LemonLDAP::NG session attribute in the Exported Attributes section

#### Options

- Basic
  - Client ID: Client ID for this RP
  - Client secret: Client secret for this RP (can be use for symmetric signature)
  - Public client (since version `2.0.4`): set this RP as public client, so authentication is not needed on token endpoint
  - Redirection addresses: Space separated list of redirect addresses allowed for this RP

- Advanced
  - Bypass consent: Enable if you never want to display the scope sharing consent screen (consent will be accepted by default). Bypassing the consent is not compliant with OpenID Connect standard.
  - User attribute: session field that will be used as main identifier (`sub`)
  - Force claims to be returned in ID Token: This options will make user attributes from the requested scope appear as ID Token claims.
  - Additional audiences (since version `2.0.8`): You can specify a space-separate list of audiences that will be added the audiences of the ID Token
  - Use refresh tokens (since version `2.0.7`): If this option is set, LemonLDAP::NG will issue a Refresh Token that can be used to obtain new access tokens as long as the user session is still valid.
- Timeouts
  - Authorization Code expiration: Expiration time of authorization code, when using the Authorization Code flow. The default value is one minute.
  - ID Token expiration: Expiration time of ID Tokens. The default value is one hour.
  - Access token expiration: Expiration time of Access Tokens. The default value is one hour.
  - Offline session expiration: This sets the lifetime of the refresh token obtained with the offline_access scope. The default value is one month. This parameter only applies if offline sessions are enabled.

- Security
  - ID Token signature algorithm: Select one of `none`, `HS256`, `HS384`, `HS512`, `RS256`, `RS384`, `RS512`
  - Require PKCE (since version `2.0.4`): a code challenge is required at token endpoint (see RFC7636)
  - Allow offline access (since version `2.0.7`): After enabling this feature, an application may request the offline_access scope, and will obtain a Refresh Token that persists even after the user has logged off. See https://openid.net/specs/openid-connect-core-1_0.html#OfflineAccess for details. These offline sessions can be administered through the Session Browser.
  - Allow OAuth2.0 Password Grant (since version `2.0.8`): Allow the use of the Resource Owner Password Credentials Grant on by this client. This feature only works if you have configured a form-based authentication module.
  - Access Rule: lets you specify a Perl rule to restrict access to this client
- Logout
  - Allowed redirection addresses for logout: A space separated list of URLs that this client can redirect the user to once the logout is done (through `post_logout_redirect_uri`)
  - URL: Specify the relying party's logout URL
  - Type: Type of Logout to perform (only Front-Channel is implemented for now)
  - Session required: Whether to send the Session ID in the logout request

#### Macros

You can define here macros that will be only evaluated for this service, and not registered in the session of the user.

#### Display

- Display name: Name of the RP application
- Logo: Logo of the RP application