Posted by Robin Vickery on 12/09/05 15:56

On 12/9/05, Binay(Local) <binay@oliveinternet.com> wrote:
> Hi All
>
> Has anybody got the working code to apply the PKCS#5 padding to the text for encryption. Please let me know as it seems PHP inbuilt functions do not support this padding at all. Been worried about from past 2 days. Help me out.

The pad function simply returns the text padded to the blocksize.

The unpad function returns the unpadded text, or false if the padding
isn't valid.

function pkcs5_pad ($text, $blocksize)
{
$pad = $blocksize - (strlen($text) % $blocksize);
return $text . str_repeat(chr($pad), $pad);
}

function pkcs5_unpad ($text)
{
$pad = ord($text{strlen($text)-1});
if ($pad > strlen($text)) return false;
if (!strspn($text, chr($pad), strlen($text) - $pad)) return false;
return substr($text, 0, -1 * $pad);
}

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