AES-256-CBC坏解密

Question

第1步：pbkdf2

var key = crypto.pbkdf2Sync('prancypoodle', 'sherylcrowe', 10000, 32, 'sha512'); 

创建的密码，prancy poodle，盐，它sherylcrowe一键创建键，重复10000次，出把一个32字节长的密钥（ AES-256-CBC需要这个长度）。

第2步：加密的东西

var cipher = crypto.createCipheriv('aes-256-cbc', key, 'dogsarefun'.toString("binary")); 

var crypted = cipher.update('wherearemysocks?'); 
crypted = Buffer.concat([crypted, cipher.final()]); 

第3步：解密&失败

var decipher = crypto.createDecipheriv('aes-256-cbc', key, 'dogsarefun'.toString('binary')); 

var decrypted = decipher.update(crypted); 
decrypted = Buffer.concat([decrypted, decipher.final()]); 
Error: error:06065064:digital envelope routines:EVP_DecryptFinal_ex:bad decrypt 
    at Error (native) 
    at Decipher.Cipher.final (crypto.js:150:26) 
    at repl:1:48 
    at REPLServer.defaultEval (repl.js:272:27) 
    at bound (domain.js:280:14) 
    at REPLServer.runBound [as eval] (domain.js:293:12) 
    at REPLServer.<anonymous> (repl.js:441:10) 
    at emitOne (events.js:101:20) 
    at REPLServer.emit (events.js:188:7) 
    at REPLServer.Interface._onLine (readline.js:219:10) 

我在做什么错？这看起来很正确，但却是错误的。

Answer 1

您需要为CBC模式提供IV，并且它需要是块大小（AES为16字节）。 'dogsarefun'只有10个字节，所以其余的字节未指定，可能（可能是）垃圾。

由于PKCS填充是默认的，CBC模式中使用了不正确的IV会导致不正确的填充上解密可能出现错误：套路：EVP_DecryptFinal_ex：坏解密。

P.S.注意：这是猫被猫叮的互联网。

Answer 2

您需要使用createDecipheriv函数进行解密，并且您的IV必须是16个字符。

例子：

var crypto = require('crypto'); 
var buffer = require('buffer'); 

var key = crypto.pbkdf2Sync('prancypoodle', 'sherylcrowe', 10000, 32, 'sha512'); 

// Initialization vector must be 16 characters. 
var cipher = crypto.createCipheriv('aes-256-cbc', key, 
    new Buffer('1234567812345678', 'binary')); 

var crypted = cipher.update('wherearemysocks?'); 
console.log('Encrypted: %s', crypted); 
crypted = Buffer.concat([crypted, cipher.final()]); 
// Again, IV must be 16 characters. 
var decipher = crypto.createDecipheriv('aes-256-cbc', key, 
    new Buffer('1234567812345678', 'binary')); 

var decrypted = decipher.update(crypted); 
console.log('Decrypted: %s', decrypted); 

输出：

Encrypted: #�j���(���� 
Decrypted: wherearemysocks?