Node.js加密aes-256-cbc-hmac-sha1不能工作

Question

我正在尝试使用aes-256-cbc-hmac-sha1算法与Node.js加密模块。

下面的代码片段显示了我要做的事情:

// adapted from http://stackoverflow.com/a/6046913
var crypto = require('crypto');
var data = "I am the clear text data";
console.log('Original cleartext: ' + data);
// //// WORKS
// var algorithm = 'aes-128-cbc';
// var keyBuffer = crypto.randomBytes(16);
// var ivBuffer = crypto.randomBytes(16);
// DOES NOT WORK
var algorithm = 'aes-256-cbc-hmac-sha1';
var keyBuffer = crypto.randomBytes(32);
var ivBuffer = crypto.randomBytes(16);
// var algorithm = 'aes-256-cfb8';       // ok
// var keyBuffer = crypto.randomBytes(32);
// var ivBuffer = crypto.randomBytes(16);
// var algorithm = 'aes-128-cbc-hmac-sha1'; // fail
// var keyBuffer = crypto.randomBytes(16);
// var ivBuffer = crypto.randomBytes(16);
var clearEncoding = 'utf8';
var cipherEncoding = 'hex';
var cipher = crypto.createCipheriv(algorithm, keyBuffer, ivBuffer);
var cipherChunks = [];
cipherChunks.push(cipher.update(data, clearEncoding, cipherEncoding));
cipherChunks.push(cipher.final(cipherEncoding));
console.log('ciphertext', cipherChunks.join(''));
var decipher = crypto.createDecipheriv(algorithm, keyBuffer, ivBuffer);
var plainChunks = [];
//// all at once
// var encrypted = cipherChunks.join('');
// plainChunks.push(decipher.update(encrypted, cipherEncoding, clearEncoding));
//// in pieces
for (var i = 0; i < cipherChunks.length;i++) {
  plainChunks.push(decipher.update(cipherChunks[i], cipherEncoding, clearEncoding));
}
plainChunks.push(decipher.final(clearEncoding));
// var pt = plainChunks.join('');
var pt = '';
for (i = 0; i < plainChunks.length; i++) pt += plainChunks[i].toString(clearEncoding);
console.log("UTF8 plaintext deciphered: " + pt);
console.log('GOOD with ' + algorithm + '?', pt === data);

没有包含HMAC的算法可以工作，而包含HMAC的算法则不行。它在decipher.update阶段失败了。完整的输出:

Original cleartext: I am the clear text data
ciphertext 364ddcface495bcc4e7c8c895443143a632a98d0942b8c844d53db7d770fabca
crypto.js:279
  var ret = this._binding.update(data, inputEncoding);
                          ^
TypeError: error:00000000:lib(0):func(0):reason(0)
    at Decipheriv.Cipher.update (crypto.js:279:27)
    at Object.<anonymous> (../../crypto-example.js:44:29)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)
    at startup (node.js:119:16)
    at node.js:906:3

如果我自己创建一个HMAC，但是，它工作得很好:

var crypto = require('crypto');
var data = "I am the clear text data";
var algorithm = 'sha1';
var keyBuffer = crypto.randomBytes(32);
var hmac = crypto.createHmac(algorithm, keyBuffer);
hmac.update(data);
var hash = hmac.digest('hex');
console.log('hash', hash);

你知道我做错了什么吗?还是加密模块有问题?(节点0.10.26和0.10.28测试结果相同)

谢谢

(注意，这也是一个bug: https://github.com/joyent/node/issues/7583)

Answer 1

密码部分就是aes-256-cbc部分。hmac部分就是hmac-sha1。

您必须创建两个对象，cipher/decipher实例和hmac实例。将cipher/decipher实例的输出与hmac实例一起创建一个用于验证目的的散列。

aes-256-cbc-hmac-sha1仅用于识别密码/验证等。并不是一个实际的密码。