<?php
/*************************************************************************
* password_strength.class.php *
*************************************************************************
* *
* (c) 2008-2011 Wolf Software Limited <support@wolf-software.com> *
* All Rights Reserved. *
* *
* This program 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 3 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/>. *
* *
*************************************************************************/
class Password_Strength {
private $class_name = "password strength";
private $class_version = "1.0.0";
private $class_author = "wolf software";
private $class_source = "http://www.wolf-software.com/downloads/php-classes/security-classes/password-strength-class/";
private $password = '';
private $password_info = array();
private $password_length = 0;
private $score_precision = 2;
public function class_name() {
return $this->class_name;
}
public function class_version() {
return $this->class_version;
}
public function class_author() {
return $this->class_author;
}
public function class_source() {
return $this->class_source;
}
public function __construct() {
}
public function simple_calculate() {
$password = $this->password;
$score = 0;
if(preg_match('/[0-9]+/', $password))
$score += 25;
if(preg_match('/[a-z]+/', $password))
$score += 25;
if(preg_match('/[A-Z]+/', $password))
$score += 25;
if(preg_match('/[^0-9a-zA-Z]+/', $password))
$score += 25;
if($this->password_length < 8)
$score *= ($this->password_length/8);
$this->password_info['total_score'] = $score;
$this->password_info['rating_score'] = $score;
$this->password_info['rating'] = $this->get_score_info($score);
}
public function calculate() {
$this->password_info = array();
$this->password_info['password'] = $this->password;
$this->password_info['password_length'] = $this->password_length;
if($this->password_length == 0) {
$this->password_info['total_score'] = 0;
$this->password_info['rating_score'] = 0;
$this->password_info['rating'] = 'Very Bad';
return;
}
$this->calculate_length();
$this->calculate_complexity();
$this->calculate_charset_complexity();
$this->calculate_entropy();
$total = 0;
$scoreCount = 0;
$keys = array_keys($this->password_info['details']);
foreach ($keys as $key) {
if (preg_match('/score+$/', $key)) {
$total += intval($this->password_info['details'][$key]);
$scoreCount ++;
}
}
$rating_score = round($total / $scoreCount, $this->score_precision);
$score_info = $this->get_score_info($rating_score);
$this->password_info['total_score'] = $total;
$this->password_info['rating_score'] = $rating_score;
$this->password_info['rating'] = $score_info;
ksort($this->password_info);
ksort($this->password_info['details']);
}
public function get_all_info() {
return $this->password_info;
}
public function get_score() {
return $this->password_info['rating_score'];
}
public function get_rating() {
return $this->password_info['rating'];
}
public function set_password($password) {
$this->password = $password;
$this->password_length = strlen($password);
}
private function calculate_charset_complexity() {
$password = $this->password;
$len = strlen($password);
$char = '';
$last_char = '';
$different_count = 0;
$score = 0;
if ($len <= 3) {
$score = 2;
} else {
for ($i = 0; $i < $len; $i++) {
$char = substr($password, $i, 1);
if ($i > 0) {
$last_char = substr($password, $i - 1, 1);
}
if ($char != $last_char) {
$different_count++;
}
}
if ($len <= 5) {
$score = 10;
} elseif ($different_count == 1) {
$score = 1;
$this->password_info['details']['length_score'] = min(min(floor(10 * $this->password_length / 10), 20), $this->password_info['details']['length_score']);
} elseif ($different_count == 2) {
$score = 5;
$this->password_info['details']['length_score'] = min(min(floor(20 * $this->password_length / 10), 40), $this->password_info['details']['length_score']);
} elseif ($different_count == 3) {
$score = 10;
$this->password_info['details']['length_score'] = min(min(floor(30 * $this->password_length / 10), 50), $this->password_info['details']['length_score']);
} else {
$score = round(max($this->password_info['details']['length_score'] / 10, $different_count / $len * 100), $this->score_precision);
}
}
$this->password_info['details']['charset_complexity_score'] = $score;
}
private function calculate_complexity() {
$password = $this->password;
$score = 0;
if (preg_match('/^([0-9]+)+$/', $password)) {
$score = 10;
$this->password_info['details']['charset'] = 'numeric';
} elseif (preg_match('/^([a-z]+)+$/', $password)) {
$score = 30;
$this->password_info['details']['charset'] = 'alphabetic';
} elseif (preg_match('/^([a-z0-9]+)+$/i', $password)) {
if ((preg_match('/^([a-z]+)([0-9]+)+$/i', $password, $match)) || (preg_match('/^([0-9]+)([a-z]+)+$/i', $password, $match))) {
$alpha = $match[1];
$numeric = $match[2];
$numeric_length = strlen($numeric);
if (($numeric == 111) || ($numeric == 123)) {
if (preg_match('/^([a-z]+)([0-9]+)+$/i', $password, $match)) {
$score = 31;
} else {
$score = 35;
}
$this->password_info['details']['common_numeric'] = true;
} elseif ($numeric_length == 1) {
$score = 30;
} elseif ($numeric_length <= 3) {
$score = 35;
} elseif ($numeric_length <= 5) {
$score = 40;
} elseif ($numeric_length <= 10) {
$score = 50;
} else {
$score = 60;
}
$this->password_info['details']['charset'] = 'alphanumeric';
} else {
$score = 80;
$this->password_info['details']['charset'] = 'alphanumeric';
}
} else {
$score = 100;
$this->password_info['details']['charset'] = 'alphanumeric + others';
}
$this->password_info['details']['charset_score'] = $score;
}
private function calculate_length() {
$len = $this->password_length;
$score = 0;
if ($len == 0) {
$score = 0;
} elseif ($len <= 3) {
$score = 1;
} elseif ($len <= 4) {
$score = 2;
} elseif ($len <= 5) {
$score = 10;
} elseif ($len <= 6) {
$score = 20;
} elseif ($len <= 8) {
$score = 30;
} elseif ($len <= 10) {
$score = 45;
} elseif ($len <= 15) {
$score = 75;
} elseif ($len <= 18) {
$score = 80;
} elseif ($len <= 20) {
$score = 90;
} else {
$score = 100;
}
$this->password_info['details']['length_score'] = $score;
}
private function calculate_entropy() {
$score = 0;
$password = $this->password;
$length = $this->password_length;
foreach (count_chars($password, 1) as $v) {
$p = $v / $length;
$score -= $p * log($p)/log(2);
}
$this->password_info['details']['entropy_per_character'] = round($score, $this->score_precision);
$this->password_info['details']['entropy_score'] = round(($score * $length), $this->score_precision);
}
private function get_score_info($score) {
if ($score <= 15) {
$score_info = 'Very Bad';
} elseif ($score <= 35) {
$score_info = 'Bad';
} elseif ($score <= 45) {
$score_info = 'Medium - Bad';
} elseif ($score <= 55) {
$score_info = 'Medium';
} elseif ($score <= 65) {
$score_info = 'Medium - Good';
} elseif ($score <= 75) {
$score_info = 'Good';
} elseif ($score <= 90) {
$score_info = 'Very Good';
} else {
$score_info = 'Excellent';
}
return $score_info;
}
}
?>