两个不相等的相等字符串

Question

I am comparing two strings with PHP. I am sure the strings are equal because I have echoed them on to the webpage, but the comparison always returns "bad" .

One of the strings being compared was formerly encrypted via AES-256 and was stored via cookie.

Cookie Value: _uid= YJUZI3Kzi+YrmKay9H2+k0Bl+374u5JLeYF7BSLiNfo=:mjsAHC8qJX5UpF0p8gpuNKczieZObzbGlRszGjiDQX4=

Encryption Function:

<?php
// AES 256
function aes($a,$b,$c) {
    switch($a){
        case 1:
            $d="awkwardp_general";$e="xjoiw4rifo5jw4";
            $f=mysqli_connect("localhost",$d,$e,"awkwardp_main") or die(mysqli_error($f));
            $g=mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128,MCRYPT_MODE_CBC);
            $h=mcrypt_create_iv($g,MCRYPT_DEV_URANDOM);
            $i="Value";
            $j="Keys";
            $k=array();
            $l=0;
            $m="SELECT ".$i." FROM `".$j."`";
            $n=mysqli_query($f,$m) or die(mysqli_error($f));
            while($o=mysqli_fetch_array($n)){
               $k[$l]=$o[$l];
               $l++;
            }
            $p=strlen($k[$b]);
            $q=mcrypt_encrypt(MCRYPT_RIJNDAEL_128,$k[$b],$c,MCRYPT_MODE_CBC,$h);
            $q=base64_encode($h.$q);
            return $q;
            break;
        case 2:
            $d="awkwardp_general";$e="xjoiw4rifo5jw4";
            $f=mysqli_connect("localhost",$d,$e,"awkwardp_main") or die(mysqli_error($f));
            $g=mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128,MCRYPT_MODE_CBC);
            $i="Value";
            $j="Keys";
            $k=array();
            $l=0;
            $m="SELECT ".$i." FROM `".$j."`";
            $n=mysqli_query($f,$m) or die(mysqli_error($f));
            while($o=mysqli_fetch_array($n)){
                $k[$l]=$o[$l];$l++;
            }
            $p=strlen($k[$b]);
            $q=base64_decode($c);
            $r=substr($q,0,$g);
            $s=substr($q,$g);
            $t=mcrypt_decrypt(MCRYPT_RIJNDAEL_128,$k[$b],$s,MCRYPT_MODE_CBC,$r);

            return $t;
            break;
        default:

    }
}
?>

Comparison Script:

<?php
$Value = explode(":",$_COOKIE['_uid']);
$_SERVER['REMOTE_ADDR'] == aes(2,1,$Value[0])
    ? printf("good")
    : printf("bad");
?>

Can someone tell me what the problem is?

Answer 1

Your problem is probably because of some hidden spaces. To remove them just use trim() , eg

$_SERVER['REMOTE_ADDR'] == trim(aes(2,1, trim($Value[0])))
                         //^^^^          ^^^^ See here