WordPress plugin to provide an OpenID Connect Generic client
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OpenID Connect Generic Client

License: GPLv2 or later License URI: http://www.gnu.org/licenses/gpl-2.0.html

A simple client that provides SSO or opt-in authentication against a generic OAuth2 Server implementation.

Description

This plugin allows to authenticate users against OpenID Connect OAuth2 API with Authorization Code Flow. Once installed, it can be configured to automatically authenticate users (SSO), or provide a "Login with OpenID Connect" button on the login form. After consent has been obtained, an existing user is automatically logged into WordPress, while new users are created in WordPress database.

Much of the documentation can be found on the Settings > OpenID Connect Generic dashboard page.

Table of Contents

Installation

  1. Upload to the /wp-content/plugins/ directory
  2. Activate the plugin
  3. Visit Settings > OpenID Connect and configure to meet your needs

Composer

OpenID Connect Generic on packagist

Installation:

composer require daggerhart/openid-connect-generic

Frequently Asked Questions

What is the client's Redirect URI?

Most OAuth2 servers should require a whitelist of redirect URIs for security purposes. The Redirect URI provided by this client is like so: https://example.com/wp-admin/admin-ajax.php?action=openid-connect-authorize

Replace example.com with your domain name and path to WordPress.

Can I change the client's Redirect URI?

Some OAuth2 servers do not allow for a client redirect URI to contain a query string. The default URI provided by this module leverages WordPress's admin-ajax.php endpoint as an easy way to provide a route that does not include HTML, but this will naturally involve a query string. Fortunately, this plugin provides a setting that will make use of an alternate redirect URI that does not include a query string.

On the settings page for this plugin (Dashboard > Settings > OpenID Connect Generic) there is a checkbox for Alternate Redirect URI. When checked, the plugin will use the Redirect URI https://example.com/openid-connect-authorize.

Hooks

This plugin provides a number of hooks to allow for a significant amount of customization of the plugin operations from elsewhere in the WordPress system.

Filters

Filters are WordPress hooks that are used to modify data. The first argument in a filter hook is always expected to be returned at the end of the hook.

WordPress filters API - add_filter() and apply_filters().

Most often you'll only need to use add_filter() to hook into this plugin's code.

openid-connect-generic-alter-request

Hooks directly into client before requests are sent to the OpenID Server.

Provides 2 arguments: the request array being sent to the server, and the operation currently being executed by this plugin.

Possible operations:

  • get-authentication-token
  • refresh-token
  • get-userinfo
add_filter('openid-connect-generic-alter-request', function( $request, $operation ) {
    if ( $operation == 'get-authentication-token' ) {
        $request['some_key'] = 'modified value';
    }
    
    return $request;
}, 10, 2);

openid-connect-generic-login-button-text

Modify the login button text. Default value is __( 'Login with OpenID Connect' ).

Provides 1 argument: the current login button text.

add_filter('openid-connect-generic-login-button-text, function( $text ) {
    $text = __('Login to my super cool IDP server');
    
    return $text;
});

openid-connect-generic-auth-url

Modify the authentication URL before presented to the user. This is the URL that will send the user to the IDP server for login.

Provides 1 argument: the plugin generated URL.

add_filter('openid-connect-generic-auth-url', function( $url ) {
    // Add some custom data to the url.
    $url.= '&my_custom_data=123abc';
    return $url;
}); 

openid-connect-generic-user-login-test

Determine whether or not the user should be logged into WordPress.

Provides 2 arguments: the boolean result of the test (default TRUE), and the $user_claim array from the server.

add_filter('openid-connect-generic-user-login-test', function( $result, $user_claim ) {
    // Don't let Terry login.
    if ( $user_claim['email'] == 'terry@example.com' ) {
        $result = FALSE;
    }
    
    return $result;
}, 10, 2);

openid-connect-generic-user-creation-test

Determine whether or not the user should be created. This filter is called when a new user is trying to login and they do not currently exist within WordPress.

Provides 2 arguments: the boolean result of the test (default TRUE), and the $user_claim array from the server.

add_filter('', function( $result, $user_claim ) {
    // Don't let anyone from example.com create an account.
    $email_array = explode( '@', $user_claim['email'] );
    if ( $email_array[1] == 'example.com' ) {
        $result = FALSE;
    }
    
    return $result;
}, 10, 2) 

openid-connect-generic-alter-user-claim

Modify the $user_claim before the plugin builds the $user_data array for new user created.

Deprecated - This filter is not very useful due to some changes that were added later. Recommend not using this filter, and using the openid-connect-generic-alter-user-data filter instead. Practically, you can only change the user's first_name and last_name values with this filter, but you could easily do that in openid-connect-generic-alter-user-data as well.

Provides 1 argument: the $user_claim from the server.

// Not a great example because the hook isn't very useful.
add_filter('openid-connect-generic-alter-user-claim', function( $user_claim ) {
    // Use the beginning of the user's email address as the user's first name. 
    if ( empty( $user_claim['given_name'] ) ) {
        $email_array = explode( '@', $user_claim['email'] );
        $user_claim['given_name'] = $email_array[0];
    }
    
    return $user_claim;
});

openid-connect-generic-alter-user-data

Modify a new user's data immediately before the user is created.

Provides 2 arguments: the $user_data array that will be sent to wp_insert_user(), and the $user_claim from the server.

add_filter('openid-connect-generic-alter-user-claim', function( $user_data, $user_claim ) {
    // Don't register any user with their real email address. Create a fake internal address.
    if ( !empty( $user_data['user_email'] ) ) {
        $email_array = explode( '@', $user_data['user_email'] );
        $email_array[1] = 'my-fake-domain.co';
        $user_data['user_email'] = implode( '@', $email_array );
    }
    
    return $user_data;
}, 10, 2);

openid-connect-generic-settings-fields

For extending the plugin with a new setting field (found on Dashboard > Settings > OpenID Connect Generic) that the site administrator can modify. Also useful to alter the existing settings fields.

See /includes/openid-connect-generic-settings-page.php for how fields are constructed.

New settings fields will be automatically saved into the wp_option for this plugin's settings, and will be available in the \OpenID_Connect_Generic_Option_Settings object this plugin uses.

Note: It can be difficult to get a copy of the settings from within other hooks. The easiest way to make use of settings in your custom hooks is to call $settings = get_option('openid_connect_generic_settings', array());.

Provides 1 argument: the existing fields array.

add_filter('openid-connect-generic-settings-fields', function( $fields ) {

    // Modify an existing field's title.
    $fields['endpoint_userinfo']['title'] = __('User information endpoint url');
    
    // Add a new field that is a simple checkbox.
    $fields['block_terry'] = array(
        'title' => __('Block Terry'),
        'description' => __('Prevent Terry from logging in'),
        'type' => 'checkbox',
        'section' => 'authorization_settings',
    );
    
    // A select field that provides options.
    
    $fields['deal_with_terry'] = array(
        'title' => __('Manage Terry'),
        'description' => __('How to deal with Terry when he tries to log in.'),
        'type' => 'select',
        'options' => array(
            'allow' => __('Allow login'),
            'block' => __('Block'),
            'redirect' => __('Redirect'),
        ),
        'section' => 'authorization_settings',
    );
    
    return $fields;
});

"Sections" are where your setting appears on the admin settings page. Keys for settings sections:

  • client_settings
  • user_settings
  • authorization_settings
  • log_settings

Field types:

  • text
  • checkbox
  • select (requires an array of "options")

Actions

WordPress actions are generic events that other plugins can react to.

Actions API: add_action and do_actions

You'll probably only ever want to use add_action when hooking into this plugin.

openid-connect-generic-user-create

React to a new user being created by this plugin.

Provides 2 arguments: the \WP_User object that was created, and the $user_claim from the IDP server.

add_action('openid-connect-generic-user-create', function( $user, $user_claim ) {
    // Send the user an email when their account is first created.
    wp_mail( 
        $user->user_email,
        __('Welcome to my web zone'),
        "Hi {$user->first_name},\n\nYour account has been created at my cool website.\n\n Enjoy!"
    ); 
}, 10, 2);

openid-connect-generic-user-update

React to the user being updated after login. This is the event that happens when a user logins and they already exist as a user in WordPress, as opposed to a new WordPress user being created.

Provides 1 argument: the user's WordPress user ID.

add_action('openid-connect-generic-user-update', function( $uid ) {
    // Keep track of the number of times the user has logged into the site.
    $login_count = get_user_meta( $uid, 'my-user-login-count', TRUE);
    $login_count += 1;
    add_user_meta( $uid, 'my-user-login-count', $login_count, TRUE);
});

openid-connect-generic-update-user-using-current-claim

React to an existing user logging in (after authentication and authorization).

Provides 2 arguments: the WP_User object, and the $user_claim provided by the IDP server.

add_action('openid-connect-generic-update-user-using-current-claim', function( $user, $user_claim) {
    // Based on some data in the user_claim, modify the user.
    if ( !empty( $user_claim['wp_user_role'] ) ) {
        if ( $user_claim['wp_user_role'] == 'should-be-editor' ) {
            $user->set_role( 'editor' );
        }
    }
}, 10, 2); 

openid-connect-generic-redirect-user-back

React to a user being redirected after a successful login. This hook is the last hook that will fire when a user logs in. It will only fire if the plugin setting "Redirect Back to Origin Page" is enabled at Dashboard > Settings > OpenID Connect Generic. It will fire for both new and existing users.

Provides 2 arguments: the url where the user will be redirected, and the WP_User object.

add_action('openid-connect-generic-redirect-user-back', function( $redirect_url, $user ) {
    // Take over the redirection complete. Send users somewhere special based on their capabilities.
    if ( $user->has_cap( 'edit_users' ) ) {
        wp_redirect( admin_url( 'users.php' ) );
        exit();
    }
}, 10, 2); 

User Meta Data

This plugin stores meta data about the user for both practical and debugging purposes.

  • openid-connect-generic-subject-identity - The identity of the user provided by the IDP server.
  • openid-connect-generic-last-id-token-claim - The user's most recent id_token claim, decoded and stored as an array.
  • openid-connect-generic-last-user-claim - The user's most recent user_claim, stored as an array.
  • openid-connect-generic-last-token-response - The user's most recent token_response, stored as an array.