<?php
/**
* Plugin OIDC/oAuth client class.
*
* @package OpenID_Connect_Generic
* @category Authentication
* @author Jonathan Daggerhart <jonathan@daggerhart.com>
* @copyright 2015-2020 daggerhart
* @license http://www.gnu.org/licenses/gpl-2.0.txt GPL-2.0+
*/
/**
* OpenID_Connect_Generic_Client class.
*
* Plugin OIDC/oAuth client class.
*
* @package OpenID_Connect_Generic
* @category Authentication
*/
class OpenID_Connect_Generic_Client {
/**
* The OIDC/oAuth client ID.
*
* @see OpenID_Connect_Generic_Option_Settings::client_id
*
* @var string
*/
private $client_id;
/**
* The OIDC/oAuth client secret.
*
* @see OpenID_Connect_Generic_Option_Settings::client_secret
*
* @var string
*/
private $client_secret;
/**
* The OIDC/oAuth scopes.
*
* @see OpenID_Connect_Generic_Option_Settings::scope
*
* @var string
*/
private $scope;
/**
* The OIDC/oAuth authorization endpoint URL.
*
* @see OpenID_Connect_Generic_Option_Settings::endpoint_login
*
* @var string
*/
private $endpoint_login;
/**
* The OIDC/oAuth User Information endpoint URL.
*
* @see OpenID_Connect_Generic_Option_Settings::endpoint_userinfo
*
* @var string
*/
private $endpoint_userinfo;
/**
* The OIDC/oAuth token validation endpoint URL.
*
* @see OpenID_Connect_Generic_Option_Settings::endpoint_token
*
* @var string
*/
private $endpoint_token;
/**
* The login flow "ajax" endpoint URI.
*
* @see OpenID_Connect_Generic_Option_Settings::redirect_uri
*
* @var string
*/
private $redirect_uri;
/**
* The specifically requested authentication contract at the IDP
*
* @see OpenID_Connect_Generic_Option_Settings::acr_values
*
* @var string
*/
private $acr_values;
/**
* The state time limit. States are only valid for 3 minutes.
*
* @see OpenID_Connect_Generic_Option_Settings::state_time_limit
*
* @var int
*/
private $state_time_limit = 180;
/**
* The logger object instance.
*
* @var OpenID_Connect_Generic_Option_Logger
*/
private $logger;
/**
* Client constructor.
*
* @param string $client_id @see OpenID_Connect_Generic_Option_Settings::client_id for description.
* @param string $client_secret @see OpenID_Connect_Generic_Option_Settings::client_secret for description.
* @param string $scope @see OpenID_Connect_Generic_Option_Settings::scope for description.
* @param string $endpoint_login @see OpenID_Connect_Generic_Option_Settings::endpoint_login for description.
* @param string $endpoint_userinfo @see OpenID_Connect_Generic_Option_Settings::endpoint_userinfo for description.
* @param string $endpoint_token @see OpenID_Connect_Generic_Option_Settings::endpoint_token for description.
* @param string $redirect_uri @see OpenID_Connect_Generic_Option_Settings::redirect_uri for description.
* @param string $acr_values @see OpenID_Connect_Generic_Option_Settings::acr_values for description.
* @param int $state_time_limit @see OpenID_Connect_Generic_Option_Settings::state_time_limit for description.
* @param OpenID_Connect_Generic_Option_Logger $logger The plugin logging object instance.
*/
public function __construct( $client_id, $client_secret, $scope, $endpoint_login, $endpoint_userinfo, $endpoint_token, $redirect_uri, $acr_values, $state_time_limit, $logger ) {
$this->client_id = $client_id;
$this->client_secret = $client_secret;
$this->scope = $scope;
$this->endpoint_login = $endpoint_login;
$this->endpoint_userinfo = $endpoint_userinfo;
$this->endpoint_token = $endpoint_token;
$this->redirect_uri = $redirect_uri;
$this->acr_values = $acr_values;
$this->state_time_limit = $state_time_limit;
$this->logger = $logger;
}
/**
* Provides the configured Redirect URI supplied to the IDP.
*
* @return string
*/
public function get_redirect_uri() {
return $this->redirect_uri;
}
/**
* Provide the configured IDP endpoint login URL.
*
* @return string
*/
public function get_endpoint_login_url() {
return $this->endpoint_login;
}
/**
* Validate the request for login authentication
*
* @param array<string> $request The authentication request results.
*
* @return array<string>|WP_Error
*/
public function validate_authentication_request( $request ) {
// Look for an existing error of some kind.
if ( isset( $request['error'] ) ) {
return new WP_Error( 'unknown-error', 'An unknown error occurred.', $request );
}
// Make sure we have a legitimate authentication code and valid state.
if ( ! isset( $request['code'] ) ) {
return new WP_Error( 'no-code', 'No authentication code present in the request.', $request );
}
// Check the client request state.
if ( ! isset( $request['state'] ) ) {
do_action( 'openid-connect-generic-no-state-provided' );
return new WP_Error( 'missing-state', __( 'Missing state.', 'daggerhart-openid-connect-generic' ), $request );
}
if ( ! $this->check_state( $request['state'] ) ) {
return new WP_Error( 'invalid-state', __( 'Invalid state.', 'daggerhart-openid-connect-generic' ), $request );
}
return $request;
}
/**
* Get the authorization code from the request
*
* @param array<string>|WP_Error $request The authentication request results.
*
* @return string|WP_Error
*/
public function get_authentication_code( $request ) {
if ( ! isset( $request['code'] ) ) {
return new WP_Error( 'missing-authentication-code', __( 'Missing authentication code.', 'daggerhart-openid-connect-generic' ), $request );
}
return $request['code'];
}
/**
* Using the authorization_code, request an authentication token from the IDP.
*
* @param string|WP_Error $code The authorization code.
*
* @return array<mixed>|WP_Error
*/
public function request_authentication_token( $code ) {
// Add Host header - required for when the openid-connect endpoint is behind a reverse-proxy.
$parsed_url = parse_url( $this->endpoint_token );
$host = $parsed_url['host'];
$request = array(
'body' => array(
'code' => $code,
'client_id' => $this->client_id,
'client_secret' => $this->client_secret,
'redirect_uri' => $this->redirect_uri,
'grant_type' => 'authorization_code',
'scope' => $this->scope,
),
'headers' => array( 'Host' => $host ),
);
if ( ! empty( $this->acr_values ) ) {
$request['body'] += array( 'acr_values' => $this->acr_values );
}
// Allow modifications to the request.
$request = apply_filters( 'openid-connect-generic-alter-request', $request, 'get-authentication-token' );
// Call the server and ask for a token.
$start_time = microtime( true );
$response = wp_remote_post( $this->endpoint_token, $request );
$end_time = microtime( true );
$this->logger->log( $this->endpoint_token, 'request_authentication_token', $end_time - $start_time );
if ( is_wp_error( $response ) ) {
$response->add( 'request_authentication_token', __( 'Request for authentication token failed.', 'daggerhart-openid-connect-generic' ) );
}
return $response;
}
/**
* Using the refresh token, request new tokens from the idp
*
* @param string $refresh_token The refresh token previously obtained from token response.
*
* @return array|WP_Error
*/
public function request_new_tokens( $refresh_token ) {
$request = array(
'body' => array(
'refresh_token' => $refresh_token,
'client_id' => $this->client_id,
'client_secret' => $this->client_secret,
'grant_type' => 'refresh_token',
),
);
// Allow modifications to the request.
$request = apply_filters( 'openid-connect-generic-alter-request', $request, 'refresh-token' );
// Call the server and ask for new tokens.
$start_time = microtime( true );
$response = wp_remote_post( $this->endpoint_token, $request );
$end_time = microtime( true );
$this->logger->log( $this->endpoint_token, 'request_new_tokens', $end_time - $start_time );
if ( is_wp_error( $response ) ) {
$response->add( 'refresh_token', __( 'Refresh token failed.', 'daggerhart-openid-connect-generic' ) );
}
return $response;
}
/**
* Extract and decode the token body of a token response
*
* @param array<mixed>|WP_Error $token_result The token response.
*
* @return array<mixed>|WP_Error|null
*/
public function get_token_response( $token_result ) {
if ( ! isset( $token_result['body'] ) ) {
return new WP_Error( 'missing-token-body', __( 'Missing token body.', 'daggerhart-openid-connect-generic' ), $token_result );
}
// Extract the token response from token.
$token_response = json_decode( $token_result['body'], true );
// Check that the token response body was able to be parsed.
if ( is_null( $token_response ) ) {
return new WP_Error( 'invalid-token', __( 'Invalid token.', 'daggerhart-openid-connect-generic' ), $token_result );
}
if ( isset( $token_response['error'] ) ) {
$error = $token_response['error'];
$error_description = $error;
if ( isset( $token_response['error_description'] ) ) {
$error_description = $token_response['error_description'];
}
return new WP_Error( $error, $error_description, $token_result );
}
return $token_response;
}
/**
* Exchange an access_token for a user_claim from the userinfo endpoint
*
* @param string $access_token The access token supplied from authentication user claim.
*
* @return array|WP_Error
*/
public function request_userinfo( $access_token ) {
// Allow modifications to the request.
$request = apply_filters( 'openid-connect-generic-alter-request', array(), 'get-userinfo' );
/*
* Section 5.3.1 of the spec recommends sending the access token using the authorization header
* a filter may or may not have already added headers - make sure they exist then add the token.
*/
if ( ! array_key_exists( 'headers', $request ) || ! is_array( $request['headers'] ) ) {
$request['headers'] = array();
}
$request['headers']['Authorization'] = 'Bearer ' . $access_token;
// Add Host header - required for when the openid-connect endpoint is behind a reverse-proxy.
$parsed_url = parse_url( $this->endpoint_userinfo );
$host = $parsed_url['host'];
if ( ! empty( $parsed_url['port'] ) ) {
$host .= ":{$parsed_url['port']}";
}
$request['headers']['Host'] = $host;
// Attempt the request including the access token in the query string for backwards compatibility.
$start_time = microtime( true );
$response = wp_remote_post( $this->endpoint_userinfo, $request );
$end_time = microtime( true );
$this->logger->log( $this->endpoint_userinfo, 'request_userinfo', $end_time - $start_time );
if ( is_wp_error( $response ) ) {
$response->add( 'request_userinfo', __( 'Request for userinfo failed.', 'daggerhart-openid-connect-generic' ) );
}
return $response;
}
/**
* Generate a new state, save it as a transient, and return the state hash.
*
* @param string $redirect_to The redirect URL to be used after IDP authentication.
*
* @return string
*/
public function new_state( $redirect_to ) {
// New state w/ timestamp.
$state = md5( mt_rand() . microtime( true ) );
$state_value = array(
$state => array(
'redirect_to' => $redirect_to,
),
);
set_transient( 'openid-connect-generic-state--' . $state, $state_value, $this->state_time_limit );
return $state;
}
/**
* Check the existence of a given state transient.
*
* @param string $state The state hash to validate.
*
* @return bool
*/
public function check_state( $state ) {
$state_found = true;
if ( ! get_option( '_transient_openid-connect-generic-state--' . $state ) ) {
do_action( 'openid-connect-generic-state-not-found', $state );
$state_found = false;
}
$valid = get_transient( 'openid-connect-generic-state--' . $state );
if ( ! $valid && $state_found ) {
do_action( 'openid-connect-generic-state-expired', $state );
}
return boolval( $valid );
}
/**
* Get the authorization state from the request
*
* @param array<string>|WP_Error $request The authentication request results.
*
* @return string|WP_Error
*/
public function get_authentication_state( $request ) {
if ( ! isset( $request['state'] ) ) {
return new WP_Error( 'missing-authentication-state', __( 'Missing authentication state.', 'daggerhart-openid-connect-generic' ), $request );
}
return $request['state'];
}
/**
* Ensure that the token meets basic requirements.
*
* @param array $token_response The token response.
*
* @return bool|WP_Error
*/
public function validate_token_response( $token_response ) {
/*
* Ensure 2 specific items exist with the token response in order
* to proceed with confidence: id_token and token_type == 'Bearer'
*/
if ( ! isset( $token_response['id_token'] ) ||
! isset( $token_response['token_type'] ) || strcasecmp( $token_response['token_type'], 'Bearer' )
) {
return new WP_Error( 'invalid-token-response', 'Invalid token response', $token_response );
}
return true;
}
/**
* Extract the id_token_claim from the token_response.
*
* @param array $token_response The token response.
*
* @return array|WP_Error
*/
public function get_id_token_claim( $token_response ) {
// Validate there is an id_token.
if ( ! isset( $token_response['id_token'] ) ) {
return new WP_Error( 'no-identity-token', __( 'No identity token.', 'daggerhart-openid-connect-generic' ), $token_response );
}
// Break apart the id_token in the response for decoding.
$tmp = explode( '.', $token_response['id_token'] );
if ( ! isset( $tmp[1] ) ) {
return new WP_Error( 'missing-identity-token', __( 'Missing identity token.', 'daggerhart-openid-connect-generic' ), $token_response );
}
// Extract the id_token's claims from the token.
$id_token_claim = json_decode(
base64_decode(
str_replace( // Because token is encoded in base64 URL (and not just base64).
array( '-', '_' ),
array( '+', '/' ),
$tmp[1]
)
),
true
);
return $id_token_claim;
}
/**
* Ensure the id_token_claim contains the required values.
*
* @param array $id_token_claim The ID token claim.
*
* @return bool|WP_Error
*/
public function validate_id_token_claim( $id_token_claim ) {
if ( ! is_array( $id_token_claim ) ) {
return new WP_Error( 'bad-id-token-claim', __( 'Bad ID token claim.', 'daggerhart-openid-connect-generic' ), $id_token_claim );
}
// Validate the identification data and it's value.
if ( ! isset( $id_token_claim['sub'] ) || empty( $id_token_claim['sub'] ) ) {
return new WP_Error( 'no-subject-identity', __( 'No subject identity.', 'daggerhart-openid-connect-generic' ), $id_token_claim );
}
// Validate acr values when the option is set in the configuration.
if ( ! empty( $this->acr_values ) && isset( $id_token_claim['acr'] ) ) {
if ( $this->acr_values != $id_token_claim['acr'] ) {
return new WP_Error( 'no-match-acr', __( 'No matching acr values.', 'daggerhart-openid-connect-generic' ), $id_token_claim );
}
}
return true;
}
/**
* Attempt to exchange the access_token for a user_claim.
*
* @param array $token_response The token response.
*
* @return array|WP_Error|null
*/
public function get_user_claim( $token_response ) {
// Send a userinfo request to get user claim.
$user_claim_result = $this->request_userinfo( $token_response['access_token'] );
// Make sure we didn't get an error, and that the response body exists.
if ( is_wp_error( $user_claim_result ) || ! isset( $user_claim_result['body'] ) ) {
return new WP_Error( 'bad-claim', __( 'Bad user claim.', 'daggerhart-openid-connect-generic' ), $user_claim_result );
}
$user_claim = json_decode( $user_claim_result['body'], true );
return $user_claim;
}
/**
* Make sure the user_claim has all required values, and that the subject
* identity matches of the id_token matches that of the user_claim.
*
* @param array $user_claim The authenticated user claim.
* @param array $id_token_claim The ID token claim.
*
* @return bool|WP_Error
*/
public function validate_user_claim( $user_claim, $id_token_claim ) {
// Validate the user claim.
if ( ! is_array( $user_claim ) ) {
return new WP_Error( 'invalid-user-claim', __( 'Invalid user claim.', 'daggerhart-openid-connect-generic' ), $user_claim );
}
// Allow for errors from the IDP.
if ( isset( $user_claim['error'] ) ) {
$message = __( 'Error from the IDP.', 'daggerhart-openid-connect-generic' );
if ( ! empty( $user_claim['error_description'] ) ) {
$message = $user_claim['error_description'];
}
return new WP_Error( 'invalid-user-claim-' . $user_claim['error'], $message, $user_claim );
}
// Make sure the id_token sub equals the user_claim sub, according to spec.
if ( $id_token_claim['sub'] !== $user_claim['sub'] ) {
return new WP_Error( 'incorrect-user-claim', __( 'Incorrect user claim.', 'daggerhart-openid-connect-generic' ), func_get_args() );
}
// Allow for other plugins to alter the login success.
$login_user = apply_filters( 'openid-connect-generic-user-login-test', true, $user_claim );
if ( ! $login_user ) {
return new WP_Error( 'unauthorized', __( 'Unauthorized access.', 'daggerhart-openid-connect-generic' ), $login_user );
}
return true;
}
/**
* Retrieve the subject identity from the id_token.
*
* @param array $id_token_claim The ID token claim.
*
* @return mixed
*/
public function get_subject_identity( $id_token_claim ) {
return $id_token_claim['sub'];
}
}