wp/wp-includes/session.php
changeset 5 5e2f62d02dcd
child 7 cf61fcea0001
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/session.php	Tue Jun 09 03:35:32 2015 +0200
@@ -0,0 +1,439 @@
+<?php
+/**
+ * Abstract class for managing user session tokens.
+ *
+ * @since 4.0.0
+ */
+abstract class WP_Session_Tokens {
+
+	/**
+	 * User ID.
+	 *
+	 * @since 4.0.0
+	 * @access protected
+	 * @var int User ID.
+	 */
+	protected $user_id;
+
+	/**
+	 * Protected constructor.
+	 *
+	 * @since 4.0.0
+	 *
+	 * @param int $user_id User whose session to manage.
+	 */
+	protected function __construct( $user_id ) {
+		$this->user_id = $user_id;
+	}
+
+	/**
+	 * Get a session token manager instance for a user.
+	 *
+	 * This method contains a filter that allows a plugin to swap out
+	 * the session manager for a subclass of WP_Session_Tokens.
+	 *
+	 * @since 4.0.0
+	 * @access public
+	 * @static
+	 *
+	 * @param int $user_id User whose session to manage.
+	 */
+	final public static function get_instance( $user_id ) {
+		/**
+		 * Filter the session token manager used.
+		 *
+		 * @since 4.0.0
+		 *
+		 * @param string $session Name of class to use as the manager.
+		 *                        Default 'WP_User_Meta_Session_Tokens'.
+		 */
+		$manager = apply_filters( 'session_token_manager', 'WP_User_Meta_Session_Tokens' );
+		return new $manager( $user_id );
+	}
+
+	/**
+	 * Hashes a session token for storage.
+	 *
+	 * @since 4.0.0
+	 * @access private
+	 *
+	 * @param string $token Session token to hash.
+	 * @return string A hash of the session token (a verifier).
+	 */
+	final private function hash_token( $token ) {
+		// If ext/hash is not present, use sha1() instead.
+		if ( function_exists( 'hash' ) ) {
+			return hash( 'sha256', $token );
+		} else {
+			return sha1( $token );
+		}
+	}
+
+	/**
+	 * Get a user's session.
+	 *
+	 * @since 4.0.0
+	 * @access public
+	 *
+	 * @param string $token Session token
+	 * @return array User session
+	 */
+	final public function get( $token ) {
+		$verifier = $this->hash_token( $token );
+		return $this->get_session( $verifier );
+	}
+
+	/**
+	 * Validate a user's session token as authentic.
+	 *
+	 * Checks that the given token is present and hasn't expired.
+	 *
+	 * @since 4.0.0
+	 * @access public
+	 *
+	 * @param string $token Token to verify.
+	 * @return bool Whether the token is valid for the user.
+	 */
+	final public function verify( $token ) {
+		$verifier = $this->hash_token( $token );
+		return (bool) $this->get_session( $verifier );
+	}
+
+	/**
+	 * Generate a session token and attach session information to it.
+	 *
+	 * A session token is a long, random string. It is used in a cookie
+	 * link that cookie to an expiration time and to ensure the cookie
+	 * becomes invalidated upon logout.
+	 *
+	 * This function generates a token and stores it with the associated
+	 * expiration time (and potentially other session information via the
+	 * `attach_session_information` filter).
+	 *
+	 * @since 4.0.0
+	 * @access public
+	 *
+	 * @param int $expiration Session expiration timestamp.
+	 * @return string Session token.
+	 */
+	final public function create( $expiration ) {
+		/**
+		 * Filter the information attached to the newly created session.
+		 *
+		 * Could be used in the future to attach information such as
+		 * IP address or user agent to a session.
+		 *
+		 * @since 4.0.0
+		 *
+		 * @param array $session Array of extra data.
+		 * @param int   $user_id User ID.
+		 */
+		$session = apply_filters( 'attach_session_information', array(), $this->user_id );
+		$session['expiration'] = $expiration;
+
+		// IP address.
+		if ( !empty( $_SERVER['REMOTE_ADDR'] ) ) {
+			$session['ip'] = $_SERVER['REMOTE_ADDR'];
+		}
+
+		// User-agent.
+		if ( ! empty( $_SERVER['HTTP_USER_AGENT'] ) ) {
+			$session['ua'] = wp_unslash( $_SERVER['HTTP_USER_AGENT'] );
+		}
+
+		// Timestamp
+		$session['login'] = time();
+
+		$token = wp_generate_password( 43, false, false );
+
+		$this->update( $token, $session );
+
+		return $token;
+	}
+
+	/**
+	 * Update a session token.
+	 *
+	 * @since 4.0.0
+	 * @access public
+	 *
+	 * @param string $token Session token to update.
+	 * @param array  $session Session information.
+	 */
+	final public function update( $token, $session ) {
+		$verifier = $this->hash_token( $token );
+		$this->update_session( $verifier, $session );
+	}
+
+	/**
+	 * Destroy a session token.
+	 *
+	 * @since 4.0.0
+	 * @access public
+	 *
+	 * @param string $token Session token to destroy.
+	 */
+	final public function destroy( $token ) {
+		$verifier = $this->hash_token( $token );
+		$this->update_session( $verifier, null );
+	}
+
+	/**
+	 * Destroy all session tokens for this user,
+	 * except a single token, presumably the one in use.
+	 *
+	 * @since 4.0.0
+	 * @access public
+	 *
+	 * @param string $token_to_keep Session token to keep.
+	 */
+	final public function destroy_others( $token_to_keep ) {
+		$verifier = $this->hash_token( $token_to_keep );
+		$session = $this->get_session( $verifier );
+		if ( $session ) {
+			$this->destroy_other_sessions( $verifier );
+		} else {
+			$this->destroy_all_sessions();
+		}
+	}
+
+	/**
+	 * Determine whether a session token is still valid,
+	 * based on expiration.
+	 *
+	 * @since 4.0.0
+	 * @access protected
+	 *
+	 * @param array $session Session to check.
+	 * @return bool Whether session is valid.
+	 */
+	final protected function is_still_valid( $session ) {
+		return $session['expiration'] >= time();
+	}
+
+	/**
+	 * Destroy all session tokens for a user.
+	 *
+	 * @since 4.0.0
+	 * @access public
+	 */
+	final public function destroy_all() {
+		$this->destroy_all_sessions();
+	}
+
+	/**
+	 * Destroy all session tokens for all users.
+	 *
+	 * @since 4.0.0
+	 * @access public
+	 * @static
+	 */
+	final public static function destroy_all_for_all_users() {
+		$manager = apply_filters( 'session_token_manager', 'WP_User_Meta_Session_Tokens' );
+		call_user_func( array( $manager, 'drop_sessions' ) );
+	}
+
+	/**
+	 * Retrieve all sessions of a user.
+	 *
+	 * @since 4.0.0
+	 * @access public
+	 *
+	 * @return array Sessions of a user.
+	 */
+	final public function get_all() {
+		return array_values( $this->get_sessions() );
+	}
+
+	/**
+	 * This method should retrieve all sessions of a user, keyed by verifier.
+	 *
+	 * @since 4.0.0
+	 * @access protected
+	 *
+	 * @return array Sessions of a user, keyed by verifier.
+	 */
+	abstract protected function get_sessions();
+
+	/**
+	 * This method should look up a session by its verifier (token hash).
+	 *
+	 * @since 4.0.0
+	 * @access protected
+	 *
+	 * @param string $verifier Verifier of the session to retrieve.
+	 * @return array|null The session, or null if it does not exist.
+	 */
+	abstract protected function get_session( $verifier );
+
+	/**
+	 * This method should update a session by its verifier.
+	 *
+	 * Omitting the second argument should destroy the session.
+	 *
+	 * @since 4.0.0
+	 * @access protected
+	 *
+	 * @param string $verifier Verifier of the session to update.
+	 */
+	abstract protected function update_session( $verifier, $session = null );
+
+	/**
+	 * This method should destroy all session tokens for this user,
+	 * except a single session passed.
+	 *
+	 * @since 4.0.0
+	 * @access protected
+	 *
+	 * @param string $verifier Verifier of the session to keep.
+	 */
+	abstract protected function destroy_other_sessions( $verifier );
+
+	/**
+	 * This method should destroy all sessions for a user.
+	 *
+	 * @since 4.0.0
+	 * @access protected
+	 */
+	abstract protected function destroy_all_sessions();
+
+	/**
+	 * This static method should destroy all session tokens for all users.
+	 *
+	 * @since 4.0.0
+	 * @access public
+	 * @static
+	 */
+	public static function drop_sessions() {}
+}
+
+/**
+ * Meta-based user sessions token manager.
+ *
+ * @since 4.0.0
+ */
+class WP_User_Meta_Session_Tokens extends WP_Session_Tokens {
+
+	/**
+	 * Get all sessions of a user.
+	 *
+	 * @since 4.0.0
+	 * @access protected
+	 *
+	 * @return array Sessions of a user.
+	 */
+	protected function get_sessions() {
+		$sessions = get_user_meta( $this->user_id, 'session_tokens', true );
+
+		if ( ! is_array( $sessions ) ) {
+			return array();
+		}
+
+		$sessions = array_map( array( $this, 'prepare_session' ), $sessions );
+		return array_filter( $sessions, array( $this, 'is_still_valid' ) );
+	}
+
+	/**
+	 * Converts an expiration to an array of session information.
+	 *
+	 * @param mixed $session Session or expiration.
+	 * @return array Session.
+	 */
+	protected function prepare_session( $session ) {
+		if ( is_int( $session ) ) {
+			return array( 'expiration' => $session );
+		}
+
+		return $session;
+	}
+
+	/**
+	 * Retrieve a session by its verifier (token hash).
+	 *
+	 * @since 4.0.0
+	 * @access protected
+	 *
+	 * @param string $verifier Verifier of the session to retrieve.
+	 * @return array|null The session, or null if it does not exist
+	 */
+	protected function get_session( $verifier ) {
+		$sessions = $this->get_sessions();
+
+		if ( isset( $sessions[ $verifier ] ) ) {
+			return $sessions[ $verifier ];
+		}
+
+		return null;
+	}
+
+	/**
+	 * Update a session by its verifier.
+	 *
+	 * @since 4.0.0
+	 * @access protected
+	 *
+	 * @param string $verifier Verifier of the session to update.
+	 * @param array  $session  Optional. Session. Omitting this argument destroys the session.
+	 */
+	protected function update_session( $verifier, $session = null ) {
+		$sessions = $this->get_sessions();
+
+		if ( $session ) {
+			$sessions[ $verifier ] = $session;
+		} else {
+			unset( $sessions[ $verifier ] );
+		}
+
+		$this->update_sessions( $sessions );
+	}
+
+	/**
+	 * Update a user's sessions in the usermeta table.
+	 *
+	 * @since 4.0.0
+	 * @access protected
+	 *
+	 * @param array $sessions Sessions.
+	 */
+	protected function update_sessions( $sessions ) {
+		if ( $sessions ) {
+			update_user_meta( $this->user_id, 'session_tokens', $sessions );
+		} else {
+			delete_user_meta( $this->user_id, 'session_tokens' );
+		}
+	}
+
+	/**
+	 * Destroy all session tokens for a user, except a single session passed.
+	 *
+	 * @since 4.0.0
+	 * @access protected
+	 *
+	 * @param string $verifier Verifier of the session to keep.
+	 */
+	protected function destroy_other_sessions( $verifier ) {
+		$session = $this->get_session( $verifier );
+		$this->update_sessions( array( $verifier => $session ) );
+	}
+
+	/**
+	 * Destroy all session tokens for a user.
+	 *
+	 * @since 4.0.0
+	 * @access protected
+	 */
+	protected function destroy_all_sessions() {
+		$this->update_sessions( array() );
+	}
+
+	/**
+	 * Destroy all session tokens for all users.
+	 *
+	 * @since 4.0.0
+	 * @access public
+	 * @static
+	 */
+	public static function drop_sessions() {
+		delete_metadata( 'user', 0, 'session_tokens', false, true );
+	}
+}