پیاده سازی الگوریتم base32 در php

<?php

function base32_encode($data)
{
    $alphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567';
    $binary = '';
    $result = '';

    // Convert the data to binary
    foreach (str_split($data) as $char) {
        $binary .= str_pad(decbin(ord($char)), 8, '0', STR_PAD_LEFT);
    }

    // Encode binary to Base32
    while (strlen($binary) % 5 != 0) {
        $binary .= '0';
    }

    for ($i = 0; $i < strlen($binary); $i += 5) {
        $chunk = substr($binary, $i, 5);
        $index = bindec($chunk);
        $result .= $alphabet[$index];
    }

    return $result;
}

function base32_decode($data)
{
    $alphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567';
    $binary = '';
    $result = '';

    // Convert Base32 to binary
    foreach (str_split($data) as $char) {
        $index = strpos($alphabet, $char);
        if ($index === false) {
            throw new Exception("Invalid character in Base32 string");
        }
        $binary .= str_pad(decbin($index), 5, '0', STR_PAD_LEFT);
    }

    // Remove padding
    $binary = rtrim($binary, '0');

    // Convert binary to ASCII
    for ($i = 0; $i < strlen($binary); $i += 8) {
        $chunk = substr($binary, $i, 8);
        if (strlen($chunk) < 8) {
            $chunk = str_pad($chunk, 8, '0', STR_PAD_RIGHT);
        }
        $result .= chr(bindec($chunk));
    }

    return $result;
}