经典PHP加密解密函数Authcode()修复版代码
Authcode这个函数很多人都使用,这函数来自Discuz程序,用于加密解密字符串,可以设置钥匙(key)和过期时间,在很多时候都用得着,原版的函数代码可能会生成+、/、&这样的字符,导致通过URL传值取回时被转义,导致无法解密,火端网络稍加修改,把这几个字符替换成其它字符,解密时再替换回去,这样就完美了!
代码如下:
- function authcode($string, $operation = 'DECODE', $key = '', $expiry = 0){
- if($operation == 'DECODE') {
- $string = str_replace('[a]','+',$string);
- $string = str_replace('[b]','&',$string);
- $string = str_replace('[c]','/',$string);
- }
- $ckey_length = 4;
- $key = md5($key ? $key : 'livcmsencryption ');
- $keya = md5(substr($key, 0, 16));
- $keyb = md5(substr($key, 16, 16));
- $keyc = $ckey_length ? ($operation == 'DECODE' ? substr($string, 0, $ckey_length): substr(md5(microtime()), -$ckey_length)) : '';
- $cryptkey = $keya.md5($keya.$keyc);
- $key_length = strlen($cryptkey);
- $string = $operation == 'DECODE' ? base64_decode(substr($string, $ckey_length)) : sprintf('%010d', $expiry ? $expiry + time() : 0).substr(md5($string.$keyb), 0, 16).$string;
- $string_length = strlen($string);
- $result = '';
- $box = range(0, 255);
- $rndkey = array();
- for($i = 0; $i <= 255; $i++) {
- $rndkey[$i] = ord($cryptkey[$i % $key_length]);
- }
- for($j = $i = 0; $i < 256; $i++) {
- $j = ($j + $box[$i] + $rndkey[$i]) % 256;
- $tmp = $box[$i];
- $box[$i] = $box[$j];
- $box[$j] = $tmp;
- }
- for($a = $j = $i = 0; $i < $string_length; $i++) {
- $a = ($a + 1) % 256;
- $j = ($j + $box[$a]) % 256;
- $tmp = $box[$a];
- $box[$a] = $box[$j];
- $box[$j] = $tmp;
- $result .= chr(ord($string[$i]) ^ ($box[($box[$a] + $box[$j]) % 256]));
- }
- if($operation == 'DECODE') {
- if((substr($result, 0, 10) == 0 || substr($result, 0, 10) - time() > 0) && substr($result, 10, 16) == substr(md5(substr($result, 26).$keyb), 0, 16)) {
- return substr($result, 26);
- } else {
- return '';
- }
- } else {
- $ustr = $keyc.str_replace('=', '', base64_encode($result));
- $ustr = str_replace('+','[a]',$ustr);
- $ustr = str_replace('&','[b]',$ustr);
- $ustr = str_replace('/','[c]',$ustr);
- return $ustr;
- }
- }