// +----------------------------------------------------------------------+ // | Willko Framework | // +----------------------------------------------------------------------+ // | Copyright (c) 2008-2009 Willko Cheng | // +----------------------------------------------------------------------+ // | Authors: Willko Cheng <willko@foxmail.com> | // +----------------------------------------------------------------------+ // $string 明文 或 密文 // $isEncrypt 是否加密 // $key 密匙 // 采用SHA1生成密匙簿，超过300个字符使用ZLIB压缩 function dencrypt($string, $isEncrypt = true, $key = KEY_SPACE) { if (!isset($string{0}) || !isset($key{0})) { return false; } $dynKey = $isEncrypt ? hash('sha1', microtime(true)) : substr($string, 0, 40); $fixedKey = hash('sha1', $key); $dynKeyPart1 = substr($dynKey, 0, 20); $dynKeyPart2 = substr($dynKey, 20); $fixedKeyPart1 = substr($fixedKey, 0, 20); $fixedKeyPart2 = substr($fixedKey, 20); $key = hash('sha1', $dynKeyPart1 . $fixedKeyPart1 . $dynKeyPart2 . $fixedKeyPart2); $string = $isEncrypt ? $fixedKeyPart1 . $string . $dynKeyPart2 : (isset($string{339}) ? gzuncompress(base64_decode(substr($string, 40))) : base64_decode(substr($string, 40))); $n = 0; $result = ''; $len = strlen($string); for ($n = 0; $n < $len; $n++) { $result .= chr(ord($string{$n}) ^ ord($key{$n % 40})); } return $isEncrypt ? $dynKey . str_replace('=', '', base64_encode($n > 299 ? gzcompress($result) : $result)) : substr($result, 20, -20); }