PHP AES 128位CBC加密给出大小警告

Question

我使用的是128位的AES ALgo，带有CBC密码模式加密，下面是代码：

$cc = 'my secret text';
$key = '3aa22e01c04c7059778c54d122b0273689fba00f4a166a66d15f7ba6a8ba8743';
$iv =  '1234567890123456';
$length = strlen($cc);

$cipher = mcrypt_module_open(MCRYPT_RIJNDAEL_128,'','cbc','');

mcrypt_generic_init($cipher, $key, $iv);
$encrypted = base64_encode(mcrypt_generic($cipher,$cc));
mcrypt_generic_deinit($cipher);

mcrypt_generic_init($cipher, $key, $iv);
$decrypted = mdecrypt_generic($cipher,base64_decode($encrypted));
mcrypt_generic_deinit($cipher);

echo "encrypted: " . $encrypted;
echo "\n";
echo "decrypted: " . substr($decrypted, 0, $length) . "\n";

但这给了我一个警告，输出为：

警告：mcrypt_generic_init（）：密钥大小太大；提供的长度：64，最大：32 /var/www/cipher.php第10行警告：mcrypt_generic_init（）：密钥大小太大；提供的长度：64，最大：32 /var/www/cipher.php第14行加密：vM/XVYSjs/QApdCUEQ8bdQ==解密：我的秘密文本

现在有人可以指导我为什么我面临大小问题，以及如何在不改变钥匙的情况下消除大小问题......

Answer 1

我修改了你的代码，它运行良好，请检查我的变化，好吗

$data_to_encrypt = "2~1~000024~0910~20130723092446~T~00002000~USD~F~375019001012120~0~0~00000000000~";
$key128 = "abcdef0123456789abcdef0123456789";
$iv = "0000000000000000";

$cc = $data_to_encrypt;
$key = $key128;
$iv =  $iv;
$length = strlen($cc);

$cipher = mcrypt_module_open(MCRYPT_RIJNDAEL_128,'','cbc','');

mcrypt_generic_init($cipher, $key, $iv);
$encrypted = base64_encode(mcrypt_generic($cipher,$cc));
mcrypt_generic_deinit($cipher);

mcrypt_generic_init($cipher, $key, $iv);
$decrypted = mdecrypt_generic($cipher,base64_decode($encrypted));
mcrypt_generic_deinit($cipher);

echo "encrypted: " . $encrypted;
echo "<br/>";
echo "length:".strlen($encrypted);
echo "<br/>";
echo "decrypted: " . substr($decrypted, 0, $length);

Answer 2

您正在进行128位加密，但您的密钥长度为64个十六进制字符，即265位。

要么您需要进行256位加密，要么您的密钥需要一半大小。