問題描述

這是一個加密和解密數據的 PHP 演示腳本:

Here is a PHP demo script that encrypts and decrypts data:

<?

$encryptionkey = 'h8y2p9d1';

$card_nbr = "1234";
echo "original card_nbr: $card_nbr <br>
";

$card_nbr_encrypted=encrypt_data($card_nbr);
echo "card_nbr_encrypted: $card_nbr_encrypted <br>
";

$card_nbr_decrypted=decrypt_data($card_nbr_encrypted);
echo "card_nbr_decrypted: $card_nbr_decrypted <br>
";

$len=strlen($card_nbr_decrypted);
echo "length: $len <br>
";



function encrypt_data($text){
  global $encryptionkey;
  $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
  $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
  $encrypted_text = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $encryptionkey, $text, MCRYPT_MODE_ECB, $iv);
  return $encrypted_text;
}

function decrypt_data($text){
  global $encryptionkey;
  $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
  $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
  $decrypted_text = mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $encryptionkey, $text, MCRYPT_MODE_ECB, $iv);
  return $decrypted_text;
}

?>

輸出為:

original card_nbr: 1234
card_nbr_encrypted: vY¨(Z$<§G3-??-éù3Y2ê×rz¨V?
card_nbr_decrypted: 1234  (and 28 binary characters)
length: 32 

輸出成功解密，但最后添加了 28 個二進制字符.在 Firefox 中查看 HTML 源代碼時最容易看到這一點.32 的字符串長度也證明了這一點.有什么想法嗎?

The output is successfully decrypted, but 28 binary characters are added to the end. This can most easily be seen in Firefox, when viewing HTML source. The string length of 32 also demonstrates this. Any ideas?

推薦答案

使用空字符