如何创建一个功能将加密/加密JSON数据转换为AES-128-CBC算法?

时间:2013-12-03 01:59:00

标签: php algorithm encryption cryptography

你能帮我解决我的问题吗?我在AES-128-CBC加密中找不到任何好的示例或教程AES意味着高级加密标准,我是新手。我有一个JSON格式的数据。我需要做的就是为表单数据创建加密和解密功能。使用AES-128-CBC算法。知道怎么做吗?或者示例或任何可以帮助我解决问题的链接?提前致谢。 :)顺便说一句,我在这个链接中有一个参考,但我不知道我的数据是否在AES-128-CBC算法中加密。 http://www.php.net/manual/en/function.mcrypt-encrypt.php以下是代码:

<?php
    # --- ENCRYPTION ---

    # the key should be random binary, use scrypt, bcrypt or PBKDF2 to
    # convert a string into a key
    # key is specified using hexadecimal
    $key = pack('H*', "bcb04b7e103a0cd8b54763051cef08bc55abe029fdebae5e1d417e2ffb2a00a3");

    # show key size use either 16, 24 or 32 byte keys for AES-128, 192
    # and 256 respectively
    $key_size =  strlen($key);
    echo "Key size: " . $key_size . "\n";

    $plaintext = "This string was AES-256 / CBC / ZeroBytePadding encrypted.";

    # create a random IV to use with CBC encoding
    $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);
    $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);

    # creates a cipher text compatible with AES (Rijndael block size = 128)
    # to keep the text confidential 
    # only suitable for encoded input that never ends with value 00h
    # (because of default zero padding)
    $ciphertext = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key,
                                 $plaintext, MCRYPT_MODE_CBC, $iv);

    # prepend the IV for it to be available for decryption
    $ciphertext = $iv . $ciphertext;

    # encode the resulting cipher text so it can be represented by a string
    $ciphertext_base64 = base64_encode($ciphertext);

    echo  $ciphertext_base64 . "\n";

    # === WARNING ===

    # Resulting cipher text has no integrity or authenticity added
    # and is not protected against padding oracle attacks.

    # --- DECRYPTION ---

    $ciphertext_dec = base64_decode($ciphertext_base64);

    # retrieves the IV, iv_size should be created using mcrypt_get_iv_size()
    $iv_dec = substr($ciphertext_dec, 0, $iv_size);

    # retrieves the cipher text (everything except the $iv_size in the front)
    $ciphertext_dec = substr($ciphertext_dec, $iv_size);

    # may remove 00h valued characters from end of plain text
    $plaintext_dec = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key,
                                    $ciphertext_dec, MCRYPT_MODE_CBC, $iv_dec);

    echo  $plaintext_dec . "\n";
?>

输出

Key size: 32
ENJW8mS2KaJoNB5E5CoSAAu0xARgsR1bdzFWpEn+poYw45q+73az5kYi4j+0haevext1dGrcW8Qi59txfCBV8BBj3bzRP3dFCp3CPQSJ8eU=
This string was AES-256 / CBC / ZeroBytePadding encrypted.

但是在AES-256 CBC中。如何以AES 128 CBC格式创建加密?

1 个答案:

答案 0 :(得分:0)

您可能don't want to use CBC mode in practice

相反,将well-studied PHP encryption library(最好是doesn't use mcrypt)与JSON函数结合使用,应该可以完全解决您的问题。

最简单的是defuse/php-encryption

<?php
use Defuse\Crypto\Crypto;
use Defuse\Crypto\Key;

/**
 * @param array|object $encrypted
 * @param Key $key
 * @return string
 */
function encryptJson($arrayOrObject, Key $key)
{
    $encoded = json_encode($arrayOrObject);
    return Crypto::encrypt($encoded, $key);
}

/**
 * @param string $encrypted
 * @param Key $key
 * @param bool $assoc
 * @return array|object
 */
function decryptJson($encrypted, Key $key, $assoc = false)
{
    $decrypted = Crypto::decrypt($encrypted, $key);
    return json_encode($decrypted, $assoc);
}