在PHP中解密用MCRYPT_RIJNDAEL_256加密的Python字符串

Question

我在PHP中有一个函数对文本进行加密，如下所示：

function encrypt($text)
{
    $Key = "MyKey";

    return trim(base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $Key, $text, MCRYPT_MODE_ECB, mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB), MCRYPT_RAND))));
}

如何在Python中解密这些值？

Answer 1

如果您愿意在PHP端使用MCRYPT_RIJNDAEL_128而不是256，那么这非常简单：

from Crypto.Cipher import AES
import base64
key="MyKey"

def decrypt(text)
    cipher=AES.new(key)
    return cipher.decrypt(base64.b64decode(text))

Answer 2

尽管当时@101100的答案很好，但已经不可行了。引用现在是一个断开的链接，代码将只在较旧的Pythons（<；3）上运行。

相反，pprp project似乎很好地填补了空白。在Python 2或Python 3上，只要pip install pprp，然后：

import pprp
import base64

KEY_SIZE = 16
BLOCK_SIZE = 32


def encrypt(key, plaintext):
    key = key.encode('ascii')
    plaintext = plaintext.encode('utf-8')
    padded_key = key.ljust(KEY_SIZE, b'\0')

    sg = pprp.data_source_gen(plaintext, block_size=BLOCK_SIZE)
    eg = pprp.rjindael_encrypt_gen(padded_key, sg, block_size=BLOCK_SIZE)

    ciphertext = pprp.encrypt_sink(eg)

    encoded = base64.b64encode(ciphertext)

    return encoded.decode('ascii')


def decrypt(key, encoded):
    key = key.encode('ascii')
    padded_key = key.ljust(KEY_SIZE, b'\0')

    ciphertext = base64.b64decode(encoded.encode('ascii'))

    sg = pprp.data_source_gen(ciphertext, block_size=BLOCK_SIZE)
    dg = pprp.rjindael_decrypt_gen(padded_key, sg, block_size=BLOCK_SIZE)

    return pprp.decrypt_sink(dg).decode('utf-8')


key = 'MyKey'
text = 'test'

encoded = encrypt(key, text)
print(repr(encoded))
# prints 'ju0pt5Y63Vj4qiViL4VL83Wjgirq4QsGDkj+tDcNcrw='

decoded = decrypt(key, encoded)
print(repr(decoded))
# prints 'test'

我有点沮丧，密文出来不同于你看到的101100的答案。然而，我已经使用这个技术成功地解密了在PHP中加密的数据，如OP中所述

Answer 3

要解密这种加密形式，您需要获得Rijndael的版本。可以找到一个here。然后需要模拟PHP Mcrypt模块中使用的键和文本填充。他们添加'\0'将文本和键填充到正确的大小。它们使用的是256位块大小，与您提供的密钥一起使用的密钥大小为128（如果您提供更大的密钥，可能会增加）。不幸的是，我链接到的Python实现一次只编码一个块。我已经创建了python函数来模拟python中的加密（用于测试）和解密

import rijndael
import base64

KEY_SIZE = 16
BLOCK_SIZE = 32

def encrypt(key, plaintext):
    padded_key = key.ljust(KEY_SIZE, '\0')
    padded_text = plaintext + (BLOCK_SIZE - len(plaintext) % BLOCK_SIZE) * '\0'

    # could also be one of
    #if len(plaintext) % BLOCK_SIZE != 0:
    #    padded_text = plaintext.ljust((len(plaintext) / BLOCK_SIZE) + 1 * BLOCKSIZE), '\0')
    # -OR-
    #padded_text = plaintext.ljust((len(plaintext) + (BLOCK_SIZE - len(plaintext) % BLOCK_SIZE)), '\0')

    r = rijndael.rijndael(padded_key, BLOCK_SIZE)

    ciphertext = ''
    for start in range(0, len(padded_text), BLOCK_SIZE):
        ciphertext += r.encrypt(padded_text[start:start+BLOCK_SIZE])

    encoded = base64.b64encode(ciphertext)

    return encoded


def decrypt(key, encoded):
    padded_key = key.ljust(KEY_SIZE, '\0')

    ciphertext = base64.b64decode(encoded)

    r = rijndael.rijndael(padded_key, BLOCK_SIZE)

    padded_text = ''
    for start in range(0, len(ciphertext), BLOCK_SIZE):
        padded_text += r.decrypt(ciphertext[start:start+BLOCK_SIZE])

    plaintext = padded_text.split('\x00', 1)[0]

    return plaintext

这可以如下使用：

key = 'MyKey'
text = 'test'

encoded = encrypt(key, text)
print repr(encoded)
# prints 'I+KlvwIK2e690lPLDQMMUf5kfZmdZRIexYJp1SLWRJY='

decoded = decrypt(key, encoded)
print repr(decoded)
# prints 'test'

为了进行比较，下面是PHP输出的相同文本：

$ php -a
Interactive shell

php > $key = 'MyKey';
php > $text = 'test';
php > $output = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $text, MCRYPT_MODE_ECB);
php > $encoded = base64_encode($output);
php > echo $encoded;
I+KlvwIK2e690lPLDQMMUf5kfZmdZRIexYJp1SLWRJY=