php crypt mysql password_php crypt函数加密和解密的实例分享

php crypt函数加密与解密，代码如下：

// +-----------------------

// | Wiki Framework |

// +-----------------------

// $string 明文 或 密文 必填

// $isEncrypt 是否加密 可选，默认为加密

// $key 密匙 可选，默认为空格

// $b = dencrypt($a,TRUE,'123');

// $c = dencrypt($b,false,'123');

// 采用SHA1生成密匙簿，超过300个字符使用ZLIB压缩

//by

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);

}

?>