dev-chiefworks
99 lines
1.9 KiB
PHP
99 lines
1.9 KiB
PHP
<?php
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//namespace Utils;
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/**
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* Class RandomStringGenerator
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* @package Utils
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*
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* Solution taken from here:
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* http://stackoverflow.com/a/13733588/1056679
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*/
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class RandomStringGenerator
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{
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/** @var string */
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protected $alphabet;
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/** @var int */
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protected $alphabetLength;
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/**
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* @param string $alphabet
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*/
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public function __construct($alphabet = '')
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{
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if ('' !== $alphabet) {
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$this->setAlphabet($alphabet);
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} else {
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$this->setAlphabet(
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implode(range('a', 'z'))
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. implode(range('A', 'Z'))
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. implode(range(0, 9))
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);
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}
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}
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/**
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* @param string $alphabet
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*/
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public function setAlphabet($alphabet)
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{
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$this->alphabet = $alphabet;
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$this->alphabetLength = strlen($alphabet);
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}
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/**
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* @param int $length
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* @return string
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*/
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public function generate($length)
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{
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$token = '';
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for ($i = 0; $i < $length; $i++) {
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$randomKey = $this->getRandomInteger(0, $this->alphabetLength);
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$token .= $this->alphabet[$randomKey];
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}
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return $token;
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}
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/**
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* @param int $min
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* @param int $max
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* @return int
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*/
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protected function getRandomInteger($min, $max)
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{
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$range = ($max - $min);
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if ($range < 0) {
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// Not so random...
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return $min;
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}
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$log = log($range, 2);
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// Length in bytes.
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$bytes = (int) ($log / 8) + 1;
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// Length in bits.
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$bits = (int) $log + 1;
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// Set all lower bits to 1.
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$filter = (int) (1 << $bits) - 1;
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do {
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$rnd = hexdec(bin2hex(openssl_random_pseudo_bytes($bytes)));
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// Discard irrelevant bits.
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$rnd = $rnd & $filter;
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} while ($rnd >= $range);
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return ($min + $rnd);
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}
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}
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