OpenID Connect (v5.4)

pac4j allows you to login using the OpenID Connect protocol v1.0.

It has been tested with various OpenID Connect providers: Google, AzureAD, Okta, IdentityServer3 (and 4), MitreID, Keycloak 4.6…

1) Dependency

You need to use the following module: pac4j-oidc.

Example (Maven dependency):

<dependency>
    <groupId>org.pac4j</groupId>
    <artifactId>pac4j-oidc</artifactId>
    <version>${pac4j.version}</version>
</dependency>

2) Clients

a) Indirect clients

For any OpenID Connect identity provider, you should use the generic OidcClient (or one of its subclasses). It is an indirect client for web browser based authentication. The configuration is defined via the OidcConfiguration component.

Example:

OidcConfiguration config = new OidcConfiguration();
config.setClientId(clientId);
config.setSecret(secret);
config.setDiscoveryURI(discoveryUri);
OidcClient oidcClient = new OidcClient(config);

In some cases (when the discovery url is already known for example), you can use a specific client like for Google, Azure Active Directory, Keycloak or Apple.

Example:

OidcConfiguration configuration = new OidcConfiguration();
configuration.setClientId("788339d7-1c44-4732-97c9-134cb201f01f");
configuration.setSecret("we/31zi+JYa7zOugO4TbSw0hzn+hv2wmENO9AS3T84s=");
configuration.setDiscoveryURI("https://login.microsoftonline.com/38c46e5a-21f0-46e5-940d-3ca06fd1a330/.well-known/openid-configuration");
AzureAdClient client = new AzureAdClient(configuration);

The clientId and secret will be provided by the OpenID Connect provider, as well as the discoveryUri (to read the metadata of the identity provider). If you do not define the discoveryUri, you’ll need to provide the provider metadata via the setProviderMetadata method.

An OidcProfile is returned after a successful authentication (or one of its subclasses: AzureAdProfile, GoogleOidcProfile or KeycloakOidcProfile). All the attributes returned in the ID Token will be available in the OidcProfile even if you can get the ID token directly via the getIdToken() method.

You can define the flow you want to use via the setResponseType and setResponseMode methods:

// implicit flow
config.setResponseType("id_token");
config.setResponseMode("form_post");

By default, the response_type is set to code (the authorization code flow) and the response_mode is empty.

You can define the scope to use with the setScope method:

config.setScope("openid email profile phone");

You can request to use the nonce parameter to reinforce security via:

config.setUseNonce(true);

b) Direct clients

For direct clients (web services), you can get the access token from any OpenID Connect identity provider and use that in your request to get the user profile.

For that, the HeaderClient would be appropriate, along with the UserInfoOidcAuthenticator.

OidcConfiguration config = new OidcConfiguration();
config.setClientId(clientId);
config.setSecret(secret);
config.setDiscoveryURI(discoveryUri);
UserInfoOidcAuthenticator authenticator = new UserInfoOidcAuthenticator(config);
HeaderClient client = new HeaderClient("Authorization", "Bearer ", authenticator);

The request to the server should have an Authorization header with the value as Bearer {access token}.

3) Advanced configuration

You can define how the client credentials (clientId and secret) are passed to the token endpoint with the setClientAuthenticationMethod method:

config.setClientAuthenticationMethod(ClientAuthenticationMethod.CLIENT_SECRET_BASIC);

When validating the IDToken in the login process, you can set a clock skew:

// 1 minute
config.setMaxClockSkew(60);

You can also choose your preferred algorithm to sign the JSON web tokens:

config.setPreferredJwsAlgorithm(JWSAlgorithm.RS256);

You can finally set additional parameters by using the addCustomParam(String key, String value) method:

// select display mode: page, popup, touch, and wap
config.addCustomParam("display", "popup");
// select prompt mode: none, consent, select_account
config.addCustomParam("prompt", "none");

Custom state values may be defined in the configuration using the below method:

config.setWithState(true);
config.setStateData("custom-state-value");

By default, the local session expires when the access token does, but this can be disabled using:

config.setExpireSessionWithToken(false);

The additional param TokenExpirationAdvance allows to set the time in seconds, previous to the token expiration, in which the expiration is advanced. By default it is 0 seconds.

config.setTokenExpirationAdvance(10);

Since version 5.2 and to reinforce security, the none alogithm for ID tokens (meaning no signature validation) must be explicitly accepted by using:

config.setAllowUnsignedIdTokens(true);