AES-256-CBC壞解密

Question

第1步：pbkdf2

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

創建的密碼，prancy poodle，鹽，它sherylcrowe一鍵創建鍵，重複10000次，出把一個32字節長的密鑰（ AES-256-CBC需要這個長度）。

第2步：加密的東西

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&失敗

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) 

我在做什麼錯？這看起來很正確，但卻是錯誤的。

Answer 1

您需要爲CBC模式提供IV，並且它需要是塊大小（AES爲16字節）。 'dogsarefun'只有10個字節，所以其餘的字節未指定，可能（可能是）垃圾。

由於PKCS填充是默認的，CBC模式中使用了不正確的IV會導致不正確的填充上解密可能出現錯誤：套路：EVP_DecryptFinal_ex：壞解密。

P.S.注意：這是貓被貓叮的互聯網。

Answer 2

您需要使用createDecipheriv函數進行解密，並且您的IV必須是16個字符。

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); 

輸出：

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