php實現可逆加密函數

多話不說,直接上代碼:

適用於 ID 授權碼類英文字符加密 如果需要中文的需要自行改造下.

//加密函數
function lockcode($code) {
    static $source_string = 'E5FCDG3HQA4B1NOPIJ2RSTUV67MWX89KLYZ';
    $num = $code;
    $code = '';
    while ( $num > 0) {
        $mod = $num % 35;
        $num = ($num - $mod) / 35;
        $code = $source_string[$mod].$code;
    }
    if(empty($code[3]))
        $code = str_pad($code,4,'0',STR_PAD_LEFT);
    return $code;
}
//解密函數
function unlockcode($code) {
    static $source_string = 'E5FCDG3HQA4B1NOPIJ2RSTUV67MWX89KLYZ';
    if (strrpos($code, '0') !== false)
        $code = substr($code, strrpos($code, '0')+1);
    $len = strlen($code);
    $code = strrev($code);
    $num = 0;
    for ($i=0; $i < $len; $i++) {
        $num += strpos($source_string, $code[$i]) * pow(35, $i);
    }
    return $num;
}