这个类主要是前台显示的主键ID转化成一串无规律的字符串，比较像 Youtube、Youku、Weibo之类的 id 名，从某种意义上可以防采集
在项目中，暴露给用户真实的项目ID，很有可能被恶意采集，很有可能被猜到目前有多少量（对造假不利）。
<?php
/*
Hashids
http://hashids.org/php
(c) 2013 Ivan Akimov
https://github.com/ivanakimov/hashids.php
hashids may be freely distributed under the MIT license.
*/
/**
* HashGenerator is a contract for generating hashes
*/
interface HashGenerator {
/**
* Encodes a variable number of parameters to generate a hash
*
* @param mixed ...
*
* @return string the generated hash
*/
public function encode();
/**
* Decodes a hash to the original parameter values
*
* @param string $hash the hash to decode
*
* @return array
*/
public function decode($hash);
/**
* Encodes hexadecimal values to generate a hash
*
* @param string $str hexadecimal string
*
* @return string the generated hash
*/
public function encode_hex($str);
/**
* Decodes hexadecimal hash
*
* @param string $hash
*
* @return string hexadecimal string
*/
public function decode_hex($hash);
}
class Hashids implements HashGenerator {
const VERSION = '1.0.5';
/* internal settings */
const MIN_ALPHABET_LENGTH = 16;
const SEP_DIV = 3.5;
const GUARD_DIV = 12;
/* error messages */
const E_ALPHABET_LENGTH = 'alphabet must contain at least %d unique characters';
const E_ALPHABET_SPACE = 'alphabet cannot contain spaces';
/* set at constructor */
private $_alphabet = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890';
private $_seps = 'cfhistuCFHISTU';
private $_min_hash_length = 0;
private $_math_functions = array();
private $_max_int_value = 1000000000;
const hashids_length = 6; // 加密字符串长度
const hashids_salt = 'test'; // 加密钥匙
const hashids_alphabet = ''; // 字符仓库,不填写默认为扩展里的字符仓库
private static $instance; //单例
/**
* 初始化
* @param array $options
* @return static
*/
public static function instance($length = null, $salt = null, $alphabet = null)
{
if (is_null(self::$instance)) {
if ($length === null) $length = self::hashids_length;
if ($salt === null) $salt = self::hashids_salt;
if ($alphabet === null) self::hashids_alphabet;
self::$instance = new static($salt, $length, $alphabet);
}
return self::$instance;
}
public function __construct($salt = '', $min_hash_length = 8, $alphabet = '') {
/* if either math precision library is present, raise $this->_max_int_value */
if (function_exists('gmp_add')) {
$this->_math_functions['add'] = 'gmp_add';
$this->_math_functions['div'] = 'gmp_div';
$this->_math_functions['str'] = 'gmp_strval';
} else if (function_exists('bcadd')) {
$this->_math_functions['add'] = 'bcadd';
$this->_math_functions['div'] = 'bcdiv';
$this->_math_functions['str'] = 'strval';
}
$this->_lower_max_int_value = $this->_max_int_value;
if ($this->_math_functions) {
$this->_max_int_value = PHP_INT_MAX;
}
/* handle parameters */
$this->_salt = $salt;
if ((int)$min_hash_length > 0) {
$this->_min_hash_length = (int)$min_hash_length;
}
if ($alphabet) {
$this->_alphabet = implode('', array_unique(str_split($alphabet)));
}
if (strlen($this->_alphabet) < self::MIN_ALPHABET_LENGTH) {
throw new \Exception(sprintf(self::E_ALPHABET_LENGTH, self::MIN_ALPHABET_LENGTH));
}
if (is_int(strpos($this->_alphabet, ' '))) {
throw new \Exception(self::E_ALPHABET_SPACE);
}
$alphabet_array = str_split($this->_alphabet);
$seps_array = str_split($this->_seps);
$this->_seps = implode('', array_intersect($alphabet_array, $seps_array));
$this->_alphabet = implode('', array_diff($alphabet_array, $seps_array));
$this->_seps = $this->_consistent_shuffle($this->_seps, $this->_salt);
if (!$this->_seps || (strlen($this->_alphabet) / strlen($this->_seps)) > self::SEP_DIV) {
$seps_length = (int)ceil(strlen($this->_alphabet) / self::SEP_DIV);
if ($seps_length == 1) {
$seps_length++;
}
if ($seps_length > strlen($this->_seps)) {
$diff = $seps_length - strlen($this->_seps);
$this->_seps .= substr($this->_alphabet, 0, $diff);
$this->_alphabet = substr($this->_alphabet, $diff);
} else {
$this->_seps = substr($this->_seps, 0, $seps_length);
}
}
$this->_alphabet = $this->_consistent_shuffle($this->_alphabet, $this->_salt);
$guard_count = (int)ceil(strlen($this->_alphabet) / self::GUARD_DIV);
if (strlen($this->_alphabet) < 3) {
$this->_guards = substr($this->_seps, 0, $guard_count);
$this->_seps = substr($this->_seps, $guard_count);
} else {
$this->_guards = substr($this->_alphabet, 0, $guard_count);
$this->_alphabet = substr($this->_alphabet, $guard_count);
}
}
public function encode() {
$ret = '';
$numbers = func_get_args();
if (func_num_args() == 1 && is_array(func_get_arg(0))) {
$numbers = $numbers[0];
}
if (!$numbers) {
return $ret;
}
foreach ($numbers as $number) {
$is_number = ctype_digit((string)$number);
if (!$is_number || $number < 0 || $number > $this->_max_int_value) {
return $ret;
}
}
return $this->_encode($numbers);
}
public function decode($hash) {
$ret = array();
if (!$hash || !is_string($hash) || !trim($hash)) {
return $ret;
}
return $this->_decode(trim($hash), $this->_alphabet);
}
public function encode_hex($str) {
if (!ctype_xdigit((string)$str)) {
return '';
}
$numbers = trim(chunk_split($str, 12, ' '));
$numbers = explode(' ', $numbers);
foreach ($numbers as $i => $number) {
$numbers[$i] = hexdec('1' . $number);
}
return call_user_func_array(array($this, 'encode'), $numbers);
}
public function decode_hex($hash) {
$ret = "";
$numbers = $this->decode($hash);
foreach ($numbers as $i => $number) {
$ret .= substr(dechex($number), 1);
}
return $ret;
}
public function get_max_int_value() {
return $this->_max_int_value;
}
private function _encode(array $numbers) {
$alphabet = $this->_alphabet;
$numbers_size = sizeof($numbers);
$numbers_hash_int = 0;
foreach ($numbers as $i => $number) {
$numbers_hash_int += ($number % ($i + 100));
}
$lottery = $ret = $alphabet[$numbers_hash_int % strlen($alphabet)];
foreach ($numbers as $i => $number) {
$alphabet = $this->_consistent_shuffle($alphabet, substr($lottery . $this->_salt . $alphabet, 0, strlen($alphabet)));
$ret .= $last = $this->_hash($number, $alphabet);
if ($i + 1 < $numbers_size) {
$number %= (ord($last) + $i);
$seps_index = $number % strlen($this->_seps);
$ret .= $this->_seps[$seps_index];
}
}
if (strlen($ret) < $this->_min_hash_length) {
$guard_index = ($numbers_hash_int + ord($ret[0])) % strlen($this->_guards);
$guard = $this->_guards[$guard_index];
$ret = $guard . $ret;
if (strlen($ret) < $this->_min_hash_length) {
$guard_index = ($numbers_hash_int + ord($ret[2])) % strlen($this->_guards);
$guard = $this->_guards[$guard_index];
$ret .= $guard;
}
}
$half_length = (int)(strlen($alphabet) / 2);
while (strlen($ret) < $this->_min_hash_length) {
$alphabet = $this->_consistent_shuffle($alphabet, $alphabet);
$ret = substr($alphabet, $half_length) . $ret . substr($alphabet, 0, $half_length);
$excess = strlen($ret) - $this->_min_hash_length;
if ($excess > 0) {
$ret = substr($ret, $excess / 2, $this->_min_hash_length);
}
}
return $ret;
}
private function _decode($hash, $alphabet) {
$ret = array();
$hash_breakdown = str_replace(str_split($this->_guards), ' ', $hash);
$hash_array = explode(' ', $hash_breakdown);
$i = 0;
if (sizeof($hash_array) == 3 || sizeof($hash_array) == 2) {
$i = 1;
}
$hash_breakdown = $hash_array[$i];
if (isset($hash_breakdown[0])) {
$lottery = $hash_breakdown[0];
$hash_breakdown = substr($hash_breakdown, 1);
$hash_breakdown = str_replace(str_split($this->_seps), ' ', $hash_breakdown);
$hash_array = explode(' ', $hash_breakdown);
foreach ($hash_array as $sub_hash) {
$alphabet = $this->_consistent_shuffle($alphabet, substr($lottery . $this->_salt . $alphabet, 0, strlen($alphabet)));
$ret[] = (int)$this->_unhash($sub_hash, $alphabet);
}
if ($this->_encode($ret) != $hash) {
$ret = array();
}
}
//修改为直接返回字符串
if(isset($ret[0])){
return $ret[0];
}else{
return false;
}
}
private function _consistent_shuffle($alphabet, $salt) {
if (!strlen($salt)) {
return $alphabet;
}
for ($i = strlen($alphabet) - 1, $v = 0, $p = 0; $i > 0; $i--, $v++) {
$v %= strlen($salt);
$p += $int = ord($salt[$v]);
$j = ($int + $v + $p) % $i;
$temp = $alphabet[$j];
$alphabet[$j] = $alphabet[$i];
$alphabet[$i] = $temp;
}
return $alphabet;
}
private function _hash($input, $alphabet) {
$hash = '';
$alphabet_length = strlen($alphabet);
do {
$hash = $alphabet[$input % $alphabet_length] . $hash;
if ($input > $this->_lower_max_int_value && $this->_math_functions) {
$input = $this->_math_functions['str']($this->_math_functions['div']($input, $alphabet_length));
} else {
$input = (int)($input / $alphabet_length);
}
} while ($input);
return $hash;
}
private function _unhash($input, $alphabet) {
$number = 0;
if (strlen($input) && $alphabet) {
$alphabet_length = strlen($alphabet);
$input_chars = str_split($input);
foreach ($input_chars as $i => $char) {
$pos = strpos($alphabet, $char);
if ($this->_math_functions) {
$number = $this->_math_functions['str']($this->_math_functions['add']($number, $pos * pow($alphabet_length, (strlen($input) - $i - 1))));
} else {
$number += $pos * pow($alphabet_length, (strlen($input) - $i - 1));
}
}
}
return $number;
}
}
调用Hashids类进行加密解密ID
$user_id = 11;
$hashids = Hashids::instance(8,'test11');
$encode_id = $hashids->encode($user_id); //加密
echo '<pre>';
var_dump($encode_id).PHP_EOL;
$decode_id = $hashids->decode($encode_id); //解密
echo '<pre>';
var_dump($decode_id).PHP_EOL;
exit();