Base64.class.php
2.56 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2009 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------
namespace Think\Crypt\Driver;
/**
* Base64 加密实现类
*/
class Base64
{
/**
* 加密字符串
*
* @param string $str
* 字符串
* @param string $key
* 加密key
* @param integer $expire
* 有效期（秒）
* @return string
*/
public static function encrypt($data, $key, $expire = 0)
{
$expire = sprintf('%010d', $expire ? $expire + time() : 0);
$key = md5($key);
$data = base64_encode($expire . $data);
$x = 0;
$len = strlen($data);
$l = strlen($key);
for ($i = 0; $i < $len; $i ++) {
if ($x == $l) {
$x = 0;
}
$char .= substr($key, $x, 1);
$x ++;
}
for ($i = 0; $i < $len; $i ++) {
$str .= chr(ord(substr($data, $i, 1)) + (ord(substr($char, $i, 1))) % 256);
}
return $str;
}
/**
* 解密字符串
*
* @param string $str
* 字符串
* @param string $key
* 加密key
* @return string
*/
public static function decrypt($data, $key)
{
$key = md5($key);
$x = 0;
$len = strlen($data);
$l = strlen($key);
for ($i = 0; $i < $len; $i ++) {
if ($x == $l) {
$x = 0;
}
$char .= substr($key, $x, 1);
$x ++;
}
for ($i = 0; $i < $len; $i ++) {
if (ord(substr($data, $i, 1)) < ord(substr($char, $i, 1))) {
$str .= chr((ord(substr($data, $i, 1)) + 256) - ord(substr($char, $i, 1)));
} else {
$str .= chr(ord(substr($data, $i, 1)) - ord(substr($char, $i, 1)));
}
}
$data = base64_decode($str);
$expire = substr($data, 0, 10);
if ($expire > 0 && $expire < time()) {
return '';
}
$data = substr($data, 10);
return $data;
}
}