AES - python 中的 Pycrypto 加密和 node.js 中的加密解密

Question

我查看了AES - Encryption with Crypto (node-js) / decryption with Pycrypto (python) 的帖子，因为我试图完全相反，但我似乎无法做到正确。这是我迄今为止尝试过的......

Python 加密

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

text_file = open("cryptic.txt", "w")

pad = lambda s: s + (BS - len(s) % BS) * chr(BS - len(s) % BS) 
unpad = lambda s : s[:-ord(s[len(s)-1:])]

plaintxt = 'dolladollabillzz'
iv = Random.new().read( AES.block_size )
print AES.block_size
key = 'totallyasecret!!'
cipher = AES.new(key=key, mode=AES.MODE_CBC, IV=iv)
encrypted = base64.b64encode(iv + cipher.encrypt(plaintxt))

text_file.write(encrypted)
text_file.close()

Node.js 解密

var fs = require('fs');
var crypto = require('crypto');
var Buffer = require('buffer').Buffer;

var algorithm = 'aes-128-cbc';
var key = new Buffer('totallyasecret!!', 'binary');

var cryptic = fs.readFileSync('./cryptic.txt', 'base64');
var iv = cryptic.slice(0, 16);
var ciphertext = cryptic.slice(16);

var decipher = crypto.createDecipheriv(algorithm, key, iv);
var decrypted = [decipher.update(ciphertext)];
decrypted.push(decipher.final('utf8'));
var finished = Buffer.concat(decrypted).toString('utf8');
console.log(finished);

每次我尝试运行 Node.js 解密时，都会收到错误消息：

Error: error:0606506D:digital envelope routines:EVP_DecryptFinal_ex:wrong final block length

Answer 1

由于 IV 是在 Python 中随机生成的，它可以包含任何可能的字节值。其中一些字节值不是有效的 UTF-8 字符（例如，多个字节是一个字符）并且可能导致错误地切掉 IV，从而使实际密文略有偏移。

由于 AES 是一种分组密码，因此位必须排列好才能正确解密。这应该可以解决它：

var cryptic = fs.readFileSync('./cryptic.txt', 'utf8');
cryptic = new Buffer(cryptic, 'base64');
var iv = cryptic.slice(0, 16);
var ciphertext = cryptic.slice(16);

这会将二进制字符串更改为完美处理二进制数据的缓冲区。