将 PHP 中的 openssl AES 转换为 Python AES

Question

我有一个php文件，如下：

$encryption_encoded_key = 'c7e1wJFz+PBwQix80D1MbIwwOmOceZOzFGoidzDkF5g=';

function my_encrypt($data, $key) {
    $encryption_key = base64_decode($key);
    $iv = openssl_random_pseudo_bytes(openssl_cipher_iv_length('aes-256-cfb'));

    $encrypted = openssl_encrypt($data, 'aes-256-cfb', $encryption_key, 1, $iv);

    // The $iv is just as important as the key for decrypting, so save it with encrypted data using a unique separator (::)
    return base64_encode($encrypted . '::' . $iv);
}

function my_decrypt($data, $key) {
    // Remove the base64 encoding from key
    $encryption_key = base64_decode($key);

    // To decrypt, split the encrypted data from IV - unique separator used was "::"
    list($encrypted_data, $iv) = explode('::', base64_decode($data), 2);

    return openssl_decrypt($encrypted_data, 'aes-256-cfb', $encryption_key, 1, $iv);
}

$data = 'USER_ID||NAME||EMAIL||MOBILE';
$data_encrypted = my_encrypt($data, $encryption_encoded_key);
echo $data_encrypted;
$data_decrypted = my_decrypt($data_encrypted, $encryption_encoded_key);
echo "Decrypted string: ". $data_decrypted;

这很好用，并且能够使用加密密钥进行加密/解密，现在我也有一个 python 文件：

import hashlib
import base64
from Crypto.Cipher import AES
from Crypto import Random

encryption_encoded_key = 'c7e1wJFz+PBwQix80D1MbIwwOmOceZOzFGoidzDkF5g='

def my_encrypt(data, key):
    #Remove the base64 encoding from key
    encryption_key = base64.b64decode(key)
    #Generate an initialization vector
    bs = AES.block_size
    iv = Random.new().read(bs)

    cipher = AES.new(encryption_key, AES.MODE_CFB, iv)
    #Encrypt the data using AES 256 encryption in CBC mode using our encryption key and initialization vector.
    encrypted = cipher.encrypt(data)

    #The iv is just as important as the key for decrypting, so save it with encrypted data using a unique separator (::)
    return base64.b64encode(encrypted + '::' + iv)


def my_decrypt(data, key):
    #Remove the base64 encoding from key
    encryption_key = base64.b64decode(key)

    #To decrypt, split the encrypted data from IV - unique separator used was "::"
    encrypted_data, iv = base64.b64decode(data).split('::')

    cipher = AES.new(encryption_key, AES.MODE_CFB, iv)

    return cipher.decrypt(encrypted_data)

data = 'USER_ID||NAME||EMAIL||MOBILE'

print "Actual string: %s" %(data)
data_encrypted = my_encrypt(data, encryption_encoded_key)
print data_encrypted

data_decrypted = my_decrypt(data_encrypted, encryption_encoded_key)
print "Decrypted string: %s" %(data_decrypted)

当我尝试从 python 中使用它时，它也可以正常工作，它能够加密/解密输入字符串， 我想使用php文件加密并在python中解密输出，两者都应该使用CFB模式的AES 256加密，我做错了什么？

Answer 1

要使用CFB mode，您需要为其指定段大小。 OpenSSL 有aes-256-cfb（128 位）、aes-256-cfb1（即 1 位）和aes-256-cfb8（8 位）（以及 AES-128 和 192 的类似模式）。所以你在你的 php 代码中使用 128 位 cfb。

Python 库接受 AES.new 的 segment_size 参数，但默认值为 8，因此您在两个版本中使用不同的模式。

要获取 Python 代码来解密 PHP 代码的输出，请将 128 的段大小添加到 cipher 对象：

cipher = AES.new(encryption_key, AES.MODE_CFB, iv, segment_size=128)

（注意，这是使用 PyCrypto 的较新的 PyCryptodome fork。PyCrypto 在这里有一个错误，无法工作。）

或者，您可以通过设置密码使 PHP 代码使用 CFB-8（显然不要同时更改）：

$encrypted = openssl_encrypt($data, 'aes-256-cfb8', $encryption_key, 1, $iv);