Пример #1
0
function decryptAES128ECB($data, $key, $strictPadding = false)
{
    $blocks = str_split($data, 16);
    foreach ($blocks as &$block) {
        $block = _decryptAES128ECB($block, $key);
    }
    $plaintext = implode($blocks);
    try {
        return removePKCS7Padding($plaintext);
    } catch (Exception $e) {
        if ($strictPadding) {
            throw $e;
        }
        return $plaintext;
    }
}
                $currentPadding = 16 - $attackPosition;
                $realBlock[$attackPosition] = $currentPadding ^ $trialByte ^ ord($iv[$attackPosition]);
                if ($attackPosition === 0) {
                    break 2;
                }
                for ($j = 15; $j >= $attackPosition; $j--) {
                    $fauxBlock[$j] = $currentPadding + 1 ^ $realBlock[$j] ^ ord($iv[$j]);
                }
                break;
            }
        }
    }
    return implode(array_map('chr', $realBlock));
}
// don't output if we're included into another script.
if (!debug_backtrace()) {
    print "Cracking 10 randomly selected ciphertexts:\n";
    for ($j = 0; $j < 10; $j++) {
        $key = getRandomBytes(16);
        $iv = getRandomBytes(16);
        $ciphertext = getRandomCiphertext($key, $iv);
        $blocks = str_split($ciphertext, 16);
        array_unshift($blocks, $iv);
        $blockNum = count($blocks) - 1;
        for ($i = $blockNum; $i > 0; $i--) {
            $blocks[$i] = crackBlock($blocks[$i], $key, $blocks[$i - 1]);
        }
        array_shift($blocks);
        print "{$j}: " . removePKCS7Padding(implode($blocks)) . "\n";
    }
}