Ela é apenas uma extensão do OAuth2 especificando algumas coisas que são relativamente ambíguas no OAuth2, para tentar torná-lo mais interoperável.

Por exemplo, o login do Google usa OpenID Connect (que por baixo dos panos usa OAuth2).

Mas o login do Facebook não tem suporte para OpenID Connect. Ele tem a própria implementação do OAuth2.

### OpenID (não "OpenID Connect")

 * OAuth, SPNEGO, or other authentication mechanisms. Each authenticator is responsible
 * for obtaining login credentials, resolving user information, and managing SSO
 * lifecycle operations like logout and metadata exchange.
 */
public interface SsoAuthenticator {

    /**
     * Gets the login credential for SSO authentication.
     * @return The login credential.
     */
    LoginCredential getLoginCredential();

    /**

That way, you can create a token with an expiration of, let's say, 1 week. And then when the user comes back the next day with the token, you know that user is still logged in to your system.

					<a class="link" href="${doc.url_link}" data-uri="${doc.url_link}"
						data-id="${doc.doc_id}" data-order="${s.index}">${doc.content_title}</a>
				</h3>
				<div class="body">
					<c:if test="${thumbnailSupport && !empty doc.thumbnail}">
					<div class="me-3">
						<a class="link d-none d-sm-flex" href="${doc.url_link}" data-uri="${doc.url_link}" data-id="${doc.doc_id}"
							data-order="${s.index}"

            throw new SQLRuntimeException(ex);
        }
    }

    /**
     * Closes the {@link Statement}.
     * <p>
     * If {@link Statement#close()} throws an exception, an error message is logged. The exception is not rethrown.
     * </p>
     *
     * @param statement
     *            {@link Statement}
     * @see Statement#close()
     */
    public static void close(final Statement statement) {

        this.envMap = envMap;
    }

    /**
     * Log the login activity.
     * @param user The user.
     */
    public void login(final OptionalThing<FessUserBean> user) {
        final Map<String, String> valueMap = new LinkedHashMap<>();
        valueMap.put("action", Action.LOGIN.name());
        valueMap.put("user", user.map(FessUserBean::getUserId).orElse("-"));

        return Stream.of(
                // Too short for TOK_ID + MECH_OID_LEN
                Arguments.of("too short header", new byte[] { 0x04, 0x01, 0x00 }, IllegalArgumentException.class),

                // Wrong TOK_ID
                Arguments.of("wrong TOK_ID", new byte[] { 0x00, 0x02, 0x00, 0x01 }, IllegalArgumentException.class),

    /** Configuration key for login server module name. */
    protected static final String SPNEGO_LOGIN_SERVER_MODULE = "spnego.login.server.module";

    /** Configuration key for login client module name. */
    protected static final String SPNEGO_LOGIN_CLIENT_MODULE = "spnego.login.client.module";

    /** Configuration key for Kerberos configuration file path. */

                    return "expires";
                case FessConfig.INDEX_FIELD_URL:
                    return "url";
                case FessConfig.INDEX_FIELD_doc_id:
                    return "doc_id";
                case FessConfig.INDEX_FIELD_ID:
                    return "id";
                case FessConfig.INDEX_FIELD_VERSION:
                    return "_version";

   * they were registered.
   *
   * <p>RuntimeExceptions thrown by a listener will be caught and logged. Any exception thrown
   * during {@code Executor.execute} (e.g., a {@code RejectedExecutionException}) will be caught and
   * logged.
   *
   * @param listener the listener to run when the service changes state is complete