C# 蹦蹦跳跳城堡C中的PBKDF2#

我一直在研究C#Bouncy Castle API，以找到如何进行PBKDF2密钥派生

我现在真是不知所措

我试着通读Pkcs5S2ParametersGenerator.cs和PBKDF2Params.cs文件，但我真的不知道怎么做

根据我到目前为止所做的研究，PBKDF2需要一个字符串（或char[]），它是密码、salt和迭代计数

到目前为止，最有希望和最明显的是PBKDF2Params和Pkcs5S2ParametersGenerator

所有这些似乎都不接受字符串或字符[]

有人在C#做过这件事吗？或者对此有任何线索吗？或者是已经在Java中实现了BouncyCastle并能提供帮助的人

Thanx提前了很多时间：）

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更新：我在Bouncy Castle中找到了如何做到这一点。查看下面的答案：）

经过数小时的代码阅读，我发现最简单的方法是在Pkcs5S2ParametersGenerator.cs中获取代码的一些部分，并创建我自己的类，当然它使用其他BouncyCastle API。这与Dot Net Compact Framework（Windows Mobile）完美配合。这相当于Dot Net Compact Framework 2.0/3.5中不存在的Rfc2898DeriveBytes类。好吧，也许不是完全相同的，但做的是：）

这是PKCS5/PKCS#5

使用的PRF（伪随机函数）为HMAC-SHA1

第一件事，第一件事。从下载BouncyCastle编译程序集，添加

BouncyCastle.Crypto.dll

作为项目的参考

然后用下面的代码创建新的类文件

using System;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Crypto.Digests;
using Org.BouncyCastle.Crypto.Macs;
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Security;

namespace PBKDF2_PKCS5
{
    class PBKDF2
    {

        private readonly IMac hMac = new HMac(new Sha1Digest());

        private void F(
            byte[] P,
            byte[] S,
            int c,
            byte[] iBuf,
            byte[] outBytes,
            int outOff)
        {
            byte[] state = new byte[hMac.GetMacSize()];
            ICipherParameters param = new KeyParameter(P);

            hMac.Init(param);

            if (S != null)
            {
                hMac.BlockUpdate(S, 0, S.Length);
            }

            hMac.BlockUpdate(iBuf, 0, iBuf.Length);

            hMac.DoFinal(state, 0);

            Array.Copy(state, 0, outBytes, outOff, state.Length);

            for (int count = 1; count != c; count++)
            {
                hMac.Init(param);
                hMac.BlockUpdate(state, 0, state.Length);
                hMac.DoFinal(state, 0);

                for (int j = 0; j != state.Length; j++)
                {
                    outBytes[outOff + j] ^= state[j];
                }
            }
        }

        private void IntToOctet(
            byte[] Buffer,
            int i)
        {
            Buffer[0] = (byte)((uint)i >> 24);
            Buffer[1] = (byte)((uint)i >> 16);
            Buffer[2] = (byte)((uint)i >> 8);
            Buffer[3] = (byte)i;
        }

        // Use this function to retrieve a derived key.
        // dkLen is in octets, how much bytes you want when the function to return.
        // mPassword is the password converted to bytes.
        // mSalt is the salt converted to bytes
        // mIterationCount is the how much iterations you want to perform. 


        public byte[] GenerateDerivedKey(
            int dkLen,
            byte[] mPassword,
            byte[] mSalt,
            int mIterationCount
            )
        {
            int hLen = hMac.GetMacSize();
            int l = (dkLen + hLen - 1) / hLen;
            byte[] iBuf = new byte[4];
            byte[] outBytes = new byte[l * hLen];

            for (int i = 1; i <= l; i++)
            {
                IntToOctet(iBuf, i);

                F(mPassword, mSalt, mIterationCount, iBuf, outBytes, (i - 1) * hLen);
            }

        //By this time outBytes will contain the derived key + more bytes.
       // According to the PKCS #5 v2.0: Password-Based Cryptography Standard (www.truecrypt.org/docs/pkcs5v2-0.pdf) 
       // we have to "extract the first dkLen octets to produce a derived key".

       //I am creating a byte array with the size of dkLen and then using
       //Buffer.BlockCopy to copy ONLY the dkLen amount of bytes to it
       // And finally returning it :D

        byte[] output = new byte[dkLen];

        Buffer.BlockCopy(outBytes, 0, output, 0, dkLen);

        return output;
        }


    }
}

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我自己也有这个问题，找到了一个更直接的方法。至少在BouncyCastle 1.7中，您可以这样做（在VB中使用Org.BouncyCastle.Crypto）：

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我已经用.Net的System.Security.Cryptography对它进行了测试，它是有效的

你回答自己的问题很快！你帮我省了很多时间。谢谢大家!@约翰：很高兴能帮上忙：）你真该看看埃德温的代码。如果上面有一个或多个bug，那么使用上面的方法就不太安全了……这很有帮助，谢谢。我相信您可以在这里添加算法作为参数Pkcs5S2ParametersGenerator（new Org.BouncyCastle.Crypto.Digests.Sha256Digest（））；

private void cmdDeriveKey_Click(object sender, EventArgs e)
        {
            byte[] salt = ASCIIEncoding.UTF8.GetBytes(txtSalt.Text);

            PBKDF2 passwordDerive = new PBKDF2();


      // I want the key to be used for AES-128, thus I want the derived key to be
      // 128 bits. Thus I will be using 128/8 = 16 for dkLen (Derived Key Length) . 
      //Similarly if you wanted a 256 bit key, dkLen would be 256/8 = 32. 

            byte[] result = passwordDerive.GenerateDerivedKey(16, ASCIIEncoding.UTF8.GetBytes(txtPassword.Text), salt, 1000);

           //result would now contain the derived key. Use it for whatever cryptographic purpose now :)
           //The following code is ONLY to show the derived key in a Textbox.

            string x = "";

            for (int i = 0; i < result.Length; i++)
            {
                x += result[i].ToString("X");
            }

            txtResult.Text = x;

        }

RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider();        

byte[] salt = new byte[16];

rng.GetBytes(salt);

Dim bcKeyDer As New Generators.Pkcs5S2ParametersGenerator()
bcKeyDer.Init(password, salt, keyIterations)
Dim bcparam As Parameters.KeyParameter = bcKeyDer.GenerateDerivedParameters("aes256", 256)
Dim key1() As Byte = bcparam.GetKey()