php - 寻找简单的PHP多路加密方法

Question

我需要借助 secret 静态 key 来解密加密的 POST 值字符串。

我看过 crypt() (但它只是单向的)和 Mcrypt，GnuPG，......但我对它们不满意。我认为它们对于我的简单问题来说太复杂了。我应该使用什么？我不需要 IV 形状或 super 安全的算法。是否有任何我不知道的基本 PHP 函数？

我只需要像这样向用户隐藏图像路径:
ImageJPEG(ImageCreateFromJPEG(decode($_REQUEST['encryptedImage'],'secret Key')));

Answer 1

更新(27/09/17):

从 mcrypt_encrypt自 起已弃用PHP 7.1.0 .我添加了一个简单的加密/解密使用 openssl .

function encrypt($string, $key = 'PrivateKey', $secret = 'SecretKey', $method = 'AES-256-CBC') {
    // hash
    $key = hash('sha256', $key);
    // create iv - encrypt method AES-256-CBC expects 16 bytes
    $iv = substr(hash('sha256', $secret), 0, 16);
    // encrypt
    $output = openssl_encrypt($string, $method, $key, 0, $iv);
    // encode
    return base64_encode($output);
}

function decrypt($string, $key = 'PrivateKey', $secret = 'SecretKey', $method = 'AES-256-CBC') {
    // hash
    $key = hash('sha256', $key);
    // create iv - encrypt method AES-256-CBC expects 16 bytes
    $iv = substr(hash('sha256', $secret), 0, 16);
    // decode
    $string = base64_decode($string);
    // decrypt
    return openssl_decrypt($string, $method, $key, 0, $iv);
}

$str = 'Encrypt this text';
echo "Plain: " .$str. "\n";

// encrypt
$encrypted_str = encrypt($str);
echo "Encrypted: " .$encrypted_str. "\n";

// decrypt
$decrypted_str = decrypt($encrypted_str);
echo "Decrypted: " .$decrypted_str. "\n";

原答案:

再简单不过了: (PHP < 7.1.0):

<?php 
define('SECRET',md5('Some secret key'));

function encrypt($value){
    $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
    $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
    return mcrypt_encrypt(MCRYPT_RIJNDAEL_256, SECRET, $value, MCRYPT_MODE_ECB, $iv);
}

function decrypt($value){
    $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
    $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
    return trim(mcrypt_decrypt(MCRYPT_RIJNDAEL_256, SECRET, $value, MCRYPT_MODE_ECB, $iv));
}

?>