class.tx_saltedpasswords_salts_blowfish.php

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<?php
/***************************************************************
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*
*  (c) 2009-2011 Marcus Krause <marcus#exp2009@t3sec.info>
*  All rights reserved
*
*  This script is part of the TYPO3 project. The TYPO3 project is
*  free software; you can redistribute it and/or modify
*  it under the terms of the GNU General Public License as published by
*  the Free Software Foundation; either version 2 of the License, or
*  (at your option) any later version.
*
*  The GNU General Public License can be found at
*  http://www.gnu.org/copyleft/gpl.html.
*  A copy is found in the textfile GPL.txt and important notices to the license
*  from the author is found in LICENSE.txt distributed with these scripts.
*
*
*  This script is distributed in the hope that it will be useful,
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*  GNU General Public License for more details.
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***************************************************************/
/**
 * Contains class "tx_saltedpasswords_salts_blowfish"
 * that provides Blowfish salted hashing.
 *
 * $Id: class.tx_saltedpasswords_salts_blowfish.php 10120 2011-01-18 20:03:36Z ohader $
 */


/**
 * Class that implements Blowfish salted hashing based on PHP's
 * crypt() function.
 *
 * Warning: Blowfish salted hashing with PHP's crypt() is not available
 * on every system.
 *
 * @author      Marcus Krause <marcus#exp2009@t3sec.info>
 *
 * @since       2009-09-06
 * @package     TYPO3
 * @subpackage  tx_saltedpasswords
 */
class tx_saltedpasswords_salts_blowfish extends tx_saltedpasswords_salts_md5 {
    /**
     * The default log2 number of iterations for password stretching.
     */
    const HASH_COUNT = 7;

    /**
     * The default maximum allowed log2 number of iterations for
     * password stretching.
     */
    const MAX_HASH_COUNT = 17;

    /**
     * The default minimum allowed log2 number of iterations for
     * password stretching.
     */
    const MIN_HASH_COUNT = 4;


    /**
     * Keeps log2 number
     * of iterations for password stretching.
     *
     * @var integer
     */
    static protected $hashCount;

    /**
     * Keeps maximum allowed log2 number
     * of iterations for password stretching.
     *
     * @var integer
     */
    static protected $maxHashCount;

    /**
     * Keeps minimum allowed log2 number
     * of iterations for password stretching.
     *
     * @var integer
     */
    static protected $minHashCount;

    /**
     * Keeps length of a Blowfish salt in bytes.
     *
     * @var integer
     */
    static protected $saltLengthBlowfish = 16;

    /**
     * Setting string to indicate type of hashing method (blowfish).
     *
     * @var string
     */
    static protected $settingBlowfish = '$2a$';


    /**
     * Method applies settings (prefix, hash count) to a salt.
     *
     * Overwrites {@link tx_saltedpasswords_salts_md5::applySettingsToSalt()}
     * with Blowfish specifics.
     *
     * @param   string      $salt:  a salt to apply setting to
     * @return  string      salt with setting
     */
    protected function applySettingsToSalt($salt) {
        $saltWithSettings = $salt;

        $reqLenBase64 = $this->getLengthBase64FromBytes($this->getSaltLength());

                    // salt without setting
        if (strlen($salt) == $reqLenBase64) {
            $saltWithSettings = $this->getSetting()
                . sprintf('%02u', $this->getHashCount()) . '$'
                . $salt;
        }

        return $saltWithSettings;
    }

    /**
     * Parses the log2 iteration count from a stored hash or setting string.
     *
     * @param   string      $setting: complete hash or a hash's setting string or to get log2 iteration count from
     * @return  integer     used hashcount for given hash string
     */
    protected function getCountLog2($setting) {
        $countLog2 = NULL;
        $setting = substr($setting, strlen($this->getSetting()));
        $firstSplitPos = strpos($setting, '$');

            // hashcount existing
        if (($firstSplitPos !== FALSE)
            && ($firstSplitPos <= 2) && is_numeric(substr($setting, 0, $firstSplitPos))) {
            $countLog2 = intval(substr($setting, 0, $firstSplitPos));
        }

        return $countLog2;
    }

    /**
     * Method returns log2 number of iterations for password stretching.
     *
     * @return  integer     log2 number of iterations for password stretching
     * @see     HASH_COUNT
     * @see     $hashCount
     * @see     setHashCount()
     */
    public function getHashCount() {
        return isset(self::$hashCount) ? self::$hashCount : self::HASH_COUNT;
    }

    /**
     * Method returns maximum allowed log2 number of iterations for password stretching.
     *
     * @return  integer     maximum allowed log2 number of iterations for password stretching
     * @see     MAX_HASH_COUNT
     * @see     $maxHashCount
     * @see     setMaxHashCount()
     */
    public function getMaxHashCount() {
        return isset(self::$maxHashCount) ? self::$maxHashCount : self::MAX_HASH_COUNT;
    }

    /**
     * Returns wether all prequesites for the hashing methods are matched
     *
     * @return  boolean     method available
     */
    public function isAvailable() {
        return CRYPT_BLOWFISH;
    }

    /**
     * Method returns minimum allowed log2 number of iterations for password stretching.
     *
     * @return  integer     minimum allowed log2 number of iterations for password stretching
     * @see     MIN_HASH_COUNT
     * @see     $minHashCount
     * @see     setMinHashCount()
     */
    public function getMinHashCount() {
        return isset(self::$minHashCount) ? self::$minHashCount : self::MIN_HASH_COUNT;
    }

    /**
     * Returns length of a Blowfish salt in bytes.
     *
     * Overwrites {@link tx_saltedpasswords_salts_md5::getSaltLength()}
     * with Blowfish specifics.
     *
     * @return  integer     length of a Blowfish salt in bytes
     */
    public function getSaltLength() {
        return self::$saltLengthBlowfish;
    }

    /**
     * Returns setting string of Blowfish salted hashes.
     *
     * Overwrites {@link tx_saltedpasswords_salts_md5::getSetting()}
     * with Blowfish specifics.
     *
     * @return  string      setting string of Blowfish salted hashes
     */
    public function getSetting() {
        return self::$settingBlowfish;
    }

    /**
     * Checks whether a user's hashed password needs to be replaced with a new hash.
     *
     * This is typically called during the login process when the plain text
     * password is available.  A new hash is needed when the desired iteration
     * count has changed through a change in the variable $hashCount or
     * HASH_COUNT.
     *
     * @param   string      $saltedPW: salted hash to check if it needs an update
     * @return  boolean     TRUE if salted hash needs an update, otherwise FALSE
     */
    public function isHashUpdateNeeded($saltedPW) {
            // Check whether this was an updated password.
        if ((strncmp($saltedPW, '$2', 2)) || !$this->isValidSalt($saltedPW)) {
            return TRUE;
        }
            // Check whether the iteration count used differs from the standard number.
        $countLog2 = $this->getCountLog2($saltedPW);

        return (!is_NULL($countLog2) && ($countLog2 < $this->getHashCount()));
    }

    /**
     * Method determines if a given string is a valid salt.
     *
     * Overwrites {@link tx_saltedpasswords_salts_md5::isValidSalt()} with
     * Blowfish specifics.
     *
     * @param   string      $salt: string to check
     * @return  boolean     TRUE if it's valid salt, otherwise FALSE
     */
    public function isValidSalt($salt) {
        $isValid = $skip = FALSE;

        $reqLenBase64 = $this->getLengthBase64FromBytes($this->getSaltLength());

        if (strlen($salt) >= $reqLenBase64) {
                // salt with prefixed setting
            if (!strncmp('$', $salt, 1)) {
                if (!strncmp($this->getSetting(), $salt, strlen($this->getSetting()))) {
                    $isValid = TRUE;
                    $salt = substr($salt, strrpos($salt, '$') + 1);
                } else {
                    $skip = TRUE;
                }
            }

                // checking base64 characters
            if (!$skip && (strlen($salt) >= $reqLenBase64)) {
                if (preg_match('/^[' . preg_quote($this->getItoa64(),'/') . ']{' . $reqLenBase64 . ',' . $reqLenBase64 . '}$/', substr($salt, 0, $reqLenBase64))) {
                    $isValid = TRUE;
                }
            }
        }

        return $isValid;
    }

    /**
     * Method determines if a given string is a valid salted hashed password.
     *
     * @param   string      $saltedPW: string to check
     * @return  boolean     TRUE if it's valid salted hashed password, otherwise FALSE
     */
    public function isValidSaltedPW($saltedPW) {
        $isValid = FALSE;

        $isValid = (!strncmp($this->getSetting(), $saltedPW, strlen($this->getSetting()))) ? TRUE : FALSE;

        if ($isValid) {
            $isValid = $this->isValidSalt($saltedPW);
        }

        return $isValid;
    }

    /**
     * Method sets log2 number of iterations for password stretching.
     *
     * @param   integer     $hashCount: log2 number of iterations for password stretching to set
     * @see     HASH_COUNT
     * @see     $hashCount
     * @see     getHashCount()
     */
    public function setHashCount($hashCount = NULL) {
        self::$hashCount = !is_NULL($hashCount) && is_int($hashCount) && $hashCount >= $this->getMinHashCount() && $hashCount <= $this->getMaxHashCount() ? $hashCount : self::HASH_COUNT;
    }

    /**
     * Method sets maximum allowed log2 number of iterations for password stretching.
     *
     * @param   integer     $maxHashCount: maximum allowed log2 number of iterations for password stretching to set
     * @see     MAX_HASH_COUNT
     * @see     $maxHashCount
     * @see     getMaxHashCount()
     */
    public function setMaxHashCount($maxHashCount = NULL) {
        self::$maxHashCount = !is_NULL($maxHashCount) && is_int($maxHashCount) ? $maxHashCount : self::MAX_HASH_COUNT;
    }

    /**
     * Method sets minimum allowed log2 number of iterations for password stretching.
     *
     * @param   integer     $minHashCount: minimum allowed log2 number of iterations for password stretching to set
     * @see     MIN_HASH_COUNT
     * @see     $minHashCount
     * @see     getMinHashCount()
     */
    public function setMinHashCount($minHashCount = NULL) {
        self::$minHashCount = !is_NULL($minHashCount) && is_int($minHashCount) ? $minHashCount : self::MIN_HASH_COUNT;
    }
}


if (defined('TYPO3_MODE') && isset($GLOBALS['TYPO3_CONF_VARS'][TYPO3_MODE]['XCLASS']['ext/saltedpasswords/classes/salts/class.tx_saltedpasswords_salts_blowfish.php'])) {
    include_once($GLOBALS['TYPO3_CONF_VARS'][TYPO3_MODE]['XCLASS']['ext/saltedpasswords/classes/salts/class.tx_saltedpasswords_salts_blowfish.php']);
}
?>