Proyectos de Subversion Moodle

<?php

/**

 * Licensed to Jasig under one or more contributor license

 * agreements. See the NOTICE file distributed with this work for

 * additional information regarding copyright ownership.

 *

 * Jasig licenses this file to you under the Apache License,

 * Version 2.0 (the "License"); you may not use this file except in

 * compliance with the License. You may obtain a copy of the License at:

 *

 * http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 *

 * PHP Version 7

 *

 * @file     CAS/PGTStorage/Db.php

 * @category Authentication

 * @package  PhpCAS

 * @author   Daniel Frett <daniel.frett@gmail.com>

 * @license  http://www.apache.org/licenses/LICENSE-2.0  Apache License 2.0

 * @link     https://wiki.jasig.org/display/CASC/phpCAS

 */

define('CAS_PGT_STORAGE_DB_DEFAULT_TABLE', 'cas_pgts');

/**

 * Basic class for PGT database storage

 * The CAS_PGTStorage_Db class is a class for PGT database storage.

 *

 * @class    CAS_PGTStorage_Db

 * @category Authentication

 * @package  PhpCAS

 * @author   Daniel Frett <daniel.frett@gmail.com>

 * @license  http://www.apache.org/licenses/LICENSE-2.0  Apache License 2.0

 * @link     https://wiki.jasig.org/display/CASC/phpCAS

 *

 * @ingroup internalPGTStorageDb

 */

class CAS_PGTStorage_Db extends CAS_PGTStorage_AbstractStorage

{

    /**

     * @addtogroup internalCAS_PGTStorageDb

     * @{

     */

    /**

     * the PDO object to use for database interactions

     */

    private $_pdo;

    /**

     * This method returns the PDO object to use for database interactions.

     *

     * @return PDO object

     */

    private function _getPdo()

    {

        return $this->_pdo;

    }

    /**

     * database connection options to use when creating a new PDO object

     */

    private $_dsn;

    private $_username;

    private $_password;

    private $_driver_options;

    /**

     * @var string the table to use for storing/retrieving pgt's

     */

    private $_table;

    /**

     * This method returns the table to use when storing/retrieving PGT's

     *

     * @return string the name of the pgt storage table.

     */

    private function _getTable()

    {

        return $this->_table;

    }

    // ########################################################################

    //  DEBUGGING

    // ########################################################################

    /**

     * This method returns an informational string giving the type of storage

     * used by the object (used for debugging purposes).

     *

     * @return string an informational string.

     */

    public function getStorageType()

    {

        return "db";

    }

    /**

     * This method returns an informational string giving informations on the

     * parameters of the storage.(used for debugging purposes).

     *

     * @return string an informational string.

     * @public

     */

    public function getStorageInfo()

    {

        return 'table=`'.$this->_getTable().'\'';

    }

    // ########################################################################

    //  CONSTRUCTOR

    // ########################################################################

    /**

     * The class constructor.

     *

     * @param CAS_Client $cas_parent     the CAS_Client instance that creates

     * the object.

     * @param string     $dsn_or_pdo     a dsn string to use for creating a PDO

     * object or a PDO object

     * @param string     $username       the username to use when connecting to

     * the database

     * @param string     $password       the password to use when connecting to

     * the database

     * @param string     $table          the table to use for storing and

     * retrieving PGT's

     * @param string     $driver_options any driver options to use when

     * connecting to the database

     */

    public function __construct(

        $cas_parent, $dsn_or_pdo, $username='', $password='', $table='',

        $driver_options=null

    ) {

        phpCAS::traceBegin();

        // call the ancestor's constructor

        parent::__construct($cas_parent);

        // set default values

        if ( empty($table) ) {

            $table = CAS_PGT_STORAGE_DB_DEFAULT_TABLE;

        }

        if ( !is_array($driver_options) ) {

            $driver_options = array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION);

        }

        // store the specified parameters

        if ($dsn_or_pdo instanceof PDO) {

            $this->_pdo = $dsn_or_pdo;

        } else {

            $this->_dsn = $dsn_or_pdo;

            $this->_username = $username;

            $this->_password = $password;

            $this->_driver_options = $driver_options;

        }

        // store the table name

        $this->_table = $table;

        phpCAS::traceEnd();

    }

    // ########################################################################

    //  INITIALIZATION

    // ########################################################################

    /**

     * This method is used to initialize the storage. Halts on error.

     *

     * @return void

     */

    public function init()

    {

        phpCAS::traceBegin();

        // if the storage has already been initialized, return immediatly

        if ($this->isInitialized()) {

            return;

        }

        // initialize the base object

        parent::init();

        // create the PDO object if it doesn't exist already

        if (!($this->_pdo instanceof PDO)) {

            try {

                $this->_pdo = new PDO(

                    $this->_dsn, $this->_username, $this->_password,

                    $this->_driver_options

                );

            }

            catch(PDOException $e) {

                phpCAS::error('Database connection error: ' . $e->getMessage());

            }

        }

        phpCAS::traceEnd();

    }

    // ########################################################################

    //  PDO database interaction

    // ########################################################################

    /**

     * attribute that stores the previous error mode for the PDO handle while

     * processing a transaction

     */

    private $_errMode;

    /**

     * This method will enable the Exception error mode on the PDO object

     *

     * @return void

     */

    private function _setErrorMode()

    {

        // get PDO object and enable exception error mode

        $pdo = $this->_getPdo();

        $this->_errMode = $pdo->getAttribute(PDO::ATTR_ERRMODE);

        $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    }

    /**

     * this method will reset the error mode on the PDO object

     *

     * @return void

     */

    private function _resetErrorMode()

    {

        // get PDO object and reset the error mode to what it was originally

        $pdo = $this->_getPdo();

        $pdo->setAttribute(PDO::ATTR_ERRMODE, $this->_errMode);

    }

    // ########################################################################

    //  database queries

    // ########################################################################

    // these queries are potentially unsafe because the person using this library

    // can set the table to use, but there is no reliable way to escape SQL

    // fieldnames in PDO yet

    /**

     * This method returns the query used to create a pgt storage table

     *

     * @return string the create table SQL, no bind params in query

     */

    protected function createTableSql()

    {

        return 'CREATE TABLE ' . $this->_getTable()

            . ' (pgt_iou VARCHAR(255) NOT NULL PRIMARY KEY, pgt VARCHAR(255) NOT NULL)';

    }

    /**

     * This method returns the query used to store a pgt

     *

     * @return string the store PGT SQL, :pgt and :pgt_iou are the bind params contained

     *         in the query

     */

    protected function storePgtSql()

    {

        return 'INSERT INTO ' . $this->_getTable()

            . ' (pgt_iou, pgt) VALUES (:pgt_iou, :pgt)';

    }

    /**

     * This method returns the query used to retrieve a pgt. the first column

     * of the first row should contain the pgt

     *

     * @return string the retrieve PGT SQL, :pgt_iou is the only bind param contained

     *         in the query

     */

    protected function retrievePgtSql()

    {

        return 'SELECT pgt FROM ' . $this->_getTable() . ' WHERE pgt_iou = :pgt_iou';

    }

    /**

     * This method returns the query used to delete a pgt.

     *

     * @return string the delete PGT SQL, :pgt_iou is the only bind param contained in

     *         the query

     */

    protected function deletePgtSql()

    {

        return 'DELETE FROM ' . $this->_getTable() . ' WHERE pgt_iou = :pgt_iou';

    }

    // ########################################################################

    //  PGT I/O

    // ########################################################################

    /**

     * This method creates the database table used to store pgt's and pgtiou's

     *

     * @return void

     */

    public function createTable()

    {

        phpCAS::traceBegin();

        // initialize this PGTStorage object if it hasn't been initialized yet

        if ( !$this->isInitialized() ) {

            $this->init();

        }

        // initialize the PDO object for this method

        $pdo = $this->_getPdo();

        $this->_setErrorMode();

        try {

            $pdo->beginTransaction();

            $query = $pdo->query($this->createTableSQL());

            $query->closeCursor();

            $pdo->commit();

        }

        catch(PDOException $e) {

            // attempt rolling back the transaction before throwing a phpCAS error

            try {

                $pdo->rollBack();

            }

            catch(PDOException $e) {

            }

            phpCAS::error('error creating PGT storage table: ' . $e->getMessage());

        }

        // reset the PDO object

        $this->_resetErrorMode();

        phpCAS::traceEnd();

    }

    /**

     * This method stores a PGT and its corresponding PGT Iou in the database.

     * Echoes a warning on error.

     *

     * @param string $pgt     the PGT

     * @param string $pgt_iou the PGT iou

     *

     * @return void

     */

    public function write($pgt, $pgt_iou)

    {

        phpCAS::traceBegin();

        // initialize the PDO object for this method

        $pdo = $this->_getPdo();

        $this->_setErrorMode();

        try {

            $pdo->beginTransaction();

            $query = $pdo->prepare($this->storePgtSql());

            $query->bindValue(':pgt', $pgt, PDO::PARAM_STR);

            $query->bindValue(':pgt_iou', $pgt_iou, PDO::PARAM_STR);

            $query->execute();

            $query->closeCursor();

            $pdo->commit();

        }

        catch(PDOException $e) {

            // attempt rolling back the transaction before throwing a phpCAS error

            try {

                $pdo->rollBack();

            }

            catch(PDOException $e) {

            }

            phpCAS::error('error writing PGT to database: ' . $e->getMessage());

        }

        // reset the PDO object

        $this->_resetErrorMode();

        phpCAS::traceEnd();

    }

    /**

     * This method reads a PGT corresponding to a PGT Iou and deletes the

     * corresponding db entry.

     *

     * @param string $pgt_iou the PGT iou

     *

     * @return string|false the corresponding PGT, or FALSE on error

     */

    public function read($pgt_iou)

    {

        phpCAS::traceBegin();

        $pgt = false;

        // initialize the PDO object for this method

        $pdo = $this->_getPdo();

        $this->_setErrorMode();

        try {

            $pdo->beginTransaction();

            // fetch the pgt for the specified pgt_iou

            $query = $pdo->prepare($this->retrievePgtSql());

            $query->bindValue(':pgt_iou', $pgt_iou, PDO::PARAM_STR);

            $query->execute();

            $pgt = $query->fetchColumn(0);

            $query->closeCursor();

            // delete the specified pgt_iou from the database

            $query = $pdo->prepare($this->deletePgtSql());

            $query->bindValue(':pgt_iou', $pgt_iou, PDO::PARAM_STR);

            $query->execute();

            $query->closeCursor();

            $pdo->commit();

        }

        catch(PDOException $e) {

            // attempt rolling back the transaction before throwing a phpCAS error

            try {

                $pdo->rollBack();

            }

            catch(PDOException $e) {

            }

            phpCAS::trace('error reading PGT from database: ' . $e->getMessage());

        }

        // reset the PDO object

        $this->_resetErrorMode();

        phpCAS::traceEnd();

        return $pgt;

    }

    /** @} */

}

?>