JavaScript：如何生成像C＃这样的Rfc2898DeriveBytes？ [英] JavaScript: How to generate Rfc2898DeriveBytes like C#?

问题描述

编辑：在评论中的每次讨论中，让我澄清一下，这将发生在SSL后面的服务器端。我不打算将散列密码或散列方案暴露给客户端。

Per discussion in the comments, let me clarify that this will be happening server side, behind SSL. I do not intend to expose the hashed password or the hashing scheme to the client.

假设我们有一个现有的asp.net身份数据库，其中包含默认表（aspnet_Users，aspnet_Roles等）。根据我的理解，密码哈希算法使用sha256并将salt +（哈希密码）存储为base64编码的字符串。 编辑：此假设不正确，请参阅下面的答案。

Assume we have an existing asp.net identity database with the default tables (aspnet_Users, aspnet_Roles, etc.). Based on my understanding, the password hashing algorithm uses sha256 and stores the salt + (hashed password) as a base64 encoded string. This assumption is incorrect, see answer below.

我想复制Microsoft的功能.AspNet.Identity.Crypto类具有JavaScript版本的 VerifyHashedPassword 功能。

I would like to replicate the function of the Microsoft.AspNet.Identity.Crypto class' VerifyHashedPassword function with a JavaScript version.

假设密码为 welcome1 且其asp.net哈希密码为 ADOEtXqGCnWCuuc5UOAVIvMVJWjANOA / LoVy0E4XCyUHIfJ7dfSY0Id + uJ20DTtG + A ==

Let's say that a password is welcome1 and its asp.net hashed password is ADOEtXqGCnWCuuc5UOAVIvMVJWjANOA/LoVy0E4XCyUHIfJ7dfSY0Id+uJ20DTtG+A==

到目前为止，我已经能够重现获取salt和存储子密钥的方法部分。

So far I have been able to reproduce the parts of the method that get the salt and the stored sub key.

C＃实现或多或少地执行此操作：

Where the C# implementation does more or less this:

var salt = new byte[SaltSize];
Buffer.BlockCopy(hashedPasswordBytes, 1, salt, 0, SaltSize);
var storedSubkey = new byte[PBKDF2SubkeyLength];
Buffer.BlockCopy(hashedPasswordBytes, 1 + SaltSize, storedSubkey, 0, PBKDF2SubkeyLength);

我在JavaScript中有以下内容（任何方面都不优雅）：

I have the following in JavaScript (not elegant by any stretch):

var hashedPwd = "ADOEtXqGCnWCuuc5UOAVIvMVJWjANOA/LoVy0E4XCyUHIfJ7dfSY0Id+uJ20DTtG+A==";
var hashedPasswordBytes = new Buffer(hashedPwd, 'base64');
var saltbytes = [];
var storedSubKeyBytes = [];

for(var i=1;i<hashedPasswordBytes.length;i++)
{
  if(i > 0 && i <= 16)
  {
    saltbytes.push(hashedPasswordBytes[i]);
  }
  if(i > 0 && i >16) {
    storedSubKeyBytes.push(hashedPasswordBytes[i]);
  }
}

再次，它不漂亮，但在运行后这个片段saltbytes和storedSubKeyBytes匹配字节的字节，我在C＃调试器中看到salt和storedSubkey。

Again, it ain't pretty, but after running this snippet the saltbytes and storedSubKeyBytes match byte for byte what I see in the C# debugger for salt and storedSubkey.

最后，在C＃中，Rfc2898DeriveBytes的一个实例用于根据提供的salt和密码生成一个新的子键，如下所示：

Finally, in C#, an instance of Rfc2898DeriveBytes is used to generate a new subkey based on the salt and the password provided, like so:

byte[] generatedSubkey;
using (var deriveBytes = new Rfc2898DeriveBytes(password, salt, PBKDF2IterCount))
{
   generatedSubkey = deriveBytes.GetBytes(PBKDF2SubkeyLength);
}

这就是我被困住的地方。我尝试过其他人的解决方案，例如这一个，我分别使用了Google和Node的CryptoJS和加密库，我的输出永远不会生成类似C＃版本的东西。

This is where I'm stuck. I have tried others' solutions such as this one, I have used Google's and Node's CryptoJS and crypto libraries respectively, and my output never generates anything resembling the C# version.

（例如：

var output = crypto.pbkdf2Sync(new Buffer('welcome1', 'utf16le'), 
    new Buffer(parsedSaltString), 1000, 32, 'sha256');
console.log(output.toString('base64'))

生成LSJvaDM9u7pXRfIS7QDFnmBPvsaN2z7FMXURGHIuqdY =）

generates "LSJvaDM9u7pXRfIS7QDFnmBPvsaN2z7FMXURGHIuqdY=")

许多我在网上发现的指针表明涉及编码不匹配的问题（NodeJS / UTF-8与.NET / UTF-16LE），所以我尝试使用默认的.NET编码格式进行编码，但无济于事。

Many of the pointers I've found online indicate problems involving encoding mismatches (NodeJS / UTF-8 vs. .NET / UTF-16LE), so I've tried encoding using the default .NET encoding format but to no avail.

或者我认为这些库正在做的事情我可能完全错了。但是，正确方向的任何指针都会非常感激。

Or I could be completely wrong about what I assume these libraries are doing. But any pointers in the right direction would be much appreciated.

推荐答案

好的，我认为这个问题最终变得更加简单了比我做的更多（不是他们总是）。在 pbkdf2规范上执行RTFM操作后，我进行了一些并排测试使用Node crypto和.NET加密，并在解决方案上取得了相当不错的进展。

Ok, I think this problem ended up being quite a bit simpler than I was making it (aren't they always). After performing a RTFM operation on the pbkdf2 spec, I ran some side-by-side tests with Node crypto and .NET crypto, and have made pretty good progress on a solution.

以下JavaScript代码正确解析存储的salt和subkey，然后通过使用存储的salt对其进行散列来验证给定的密码。毫无疑问，更好/更清洁/更安全的调整，欢迎评论。

The following JavaScript code correctly parses the stored salt and subkey, then verifies the given password by hashing it with the stored salt. There are doubtless better / cleaner / more secure tweaks, so comments welcome.

// NodeJS implementation of crypto, I'm sure google's 
// cryptoJS would work equally well.
var crypto = require('crypto');

// The value stored in [dbo].[AspNetUsers].[PasswordHash]
var hashedPwd = "ADOEtXqGCnWCuuc5UOAVIvMVJWjANOA/LoVy0E4XCyUHIfJ7dfSY0Id+uJ20DTtG+A==";
var hashedPasswordBytes = new Buffer(hashedPwd, 'base64');

var hexChar = ["0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "A", "B", "C", "D", "E", "F"];

var saltString = "";
var storedSubKeyString = "";

// build strings of octets for the salt and the stored key
for (var i = 1; i < hashedPasswordBytes.length; i++) {
    if (i > 0 && i <= 16) {
        saltString += hexChar[(hashedPasswordBytes[i] >> 4) & 0x0f] + hexChar[hashedPasswordBytes[i] & 0x0f]
    }
    if (i > 0 && i > 16) {
        storedSubKeyString += hexChar[(hashedPasswordBytes[i] >> 4) & 0x0f] + hexChar[hashedPasswordBytes[i] & 0x0f];
    }
}

// password provided by the user
var password = 'welcome1';

// TODO remove debug - logging passwords in prod is considered 
// tasteless for some odd reason
console.log('cleartext: ' + password);
console.log('saltString: ' + saltString);
console.log('storedSubKeyString: ' + storedSubKeyString);

// This is where the magic happens. 
// If you are doing your own hashing, you can (and maybe should)
// perform more iterations of applying the salt and perhaps
// use a stronger hash than sha1, but if you want it to work
// with the [as of 2015] Microsoft Identity framework, keep
// these settings.
var nodeCrypto = crypto.pbkdf2Sync(new Buffer(password), new Buffer(saltString, 'hex'), 1000, 256, 'sha1');

// get a hex string of the derived bytes
var derivedKeyOctets = nodeCrypto.toString('hex').toUpperCase();

console.log("hex of derived key octets: " + derivedKeyOctets);

// The first 64 bytes of the derived key should
// match the stored sub key
if (derivedKeyOctets.indexOf(storedSubKeyString) === 0) {
    console.info("passwords match!");
} else {
    console.warn("passwords DO NOT match!");
}

这篇关于JavaScript：如何生成像C＃这样的Rfc2898DeriveBytes？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！