为DSA生成40个字符指纹

Question

当您有P，Q，G，Y和X时，.NET Framework（C＃）中是否有现有方法生成40个字符（公开？）指纹，如下所示：

还是有人会知道如何实现这一目标？

指纹：81F68001 29D928AD BEE41B78 AA862106 CAEAC892

编辑：这里 是什么，我试图做一个例子：

string P = "00F35DBCD6D4C296D2FE9118B659D02608B76FAC94BB58B10283F20390E2B259BAC602466162E9EF3E6A1590702CAE49B681A75A878E266F1AFAE0FA89DA5CA44A1551B517A3F80A9D6C630F9E7D239B437F7402DF8055069735894CD9D4708F8777B5E4F3E6A8B2D4EEE50DB2C96BA16D3C81FEB923697D649A8B7771B10E5B3F"; 
    string Q = "00B5AF039839043410E04C35BDDB30679969EBAC8B"; 
    string G = "00F300A68E54DE33A09001E28EC09F2ABF5DAF208774F2514D878D5587D870C91C6DE42B4705078C6F4438765050039C2950B6DE85AFC0D12A7A5C521782CB760918DF68F385A7F177DF50AA6BA0284090454106E422FCAE5390ADC00B859A433430019E970BFA614374DE1FB40C600345EF19DC01A122E4676C614DC29D3DC2FE"; 
    string Y = "00A5317849AF22BA6498F1EF973158C8BDA848BEB074CB141E629C927B18F29C8CE99815001BAAB2931F339B5C52A79BC3DCB0C5962C302707BA6FF1807EEB91D751BA723BB7512C20689AC5E67A1B656CDFD1BA2D4F6A44308509486AA8754B47784FC4C03E546897200388656BA5834A2CC0E18E58454FF60C1BA5411D6F50FD"; 

我缺少这个中间件的代码。我如何将P，Q，G，Y转换为指纹。我尝试了不同的方法，但是我没有成功生成我在应用程序中看到的指纹，我试图重新创建。

 /* convert public key (bigIntKey) into fingerprint */ 
     var bigIntHash = new BigInteger(SHA1.Create().ComputeHash(key.ToByteArray())); 
     byte[] hash = bigIntHash.ToByteArray(); 

     if (hash.Length != 20) 
     { 
      throw new IndexOutOfRangeException(); 
     } 

     for (int i = 0; i < 5; i++) 
     { 
      int lf = BitConverter.ToInt32(hash, i * 4); 
      Debug.Write(lf.ToString("X") + " "); 
     } 

EDIT2：

我想这一点，但不工作

 // switch P, Q, G, Y and separately to make it work. 

     byte[] pArr = StringToByteArray(P); 
     pArr = Tools.Endian.ReverseBytes(pArr); 

     byte[] qArr = StringToByteArray(Q); 
     qArr = Tools.Endian.ReverseBytes(qArr); 

     byte[] gArr = StringToByteArray(G); 
     gArr = Tools.Endian.ReverseBytes(gArr); 

     byte[] yArr = StringToByteArray(Y); 
     yArr = Tools.Endian.ReverseBytes(yArr); 

     byte[] xArr = StringToByteArray(X); 
     xArr = Tools.Endian.ReverseBytes(xArr); 

     byte[] arr = Combine(pArr, qArr, gArr, yArr); 

     DSACryptoServiceProvider dsa = new DSACryptoServiceProvider(); 
     DSAParameters par = new DSAParameters(); 
     par.P = pArr; 
     par.Q = qArr; 
     par.G = gArr; 
     par.Y = yArr; 
     par.X = xArr; 
     dsa.ImportParameters(par); 
     var xml = dsa.ToXmlString(true); 

它将失败的ImportParameter。

谢谢

Answer 1

您需要遵循OTR规范，该规范说明了密钥使用MPI编码的组成部分，它指定为长度（32位大端），后跟整数（大端，无前导零）

void Main() 
{ 
    string P = "00F35DBCD6D4C296D2FE9118B659D02608B76FAC94BB58B10283F20390E2B259BAC602466162E9EF3E6A1590702CAE49B681A75A878E266F1AFAE0FA89DA5CA44A1551B517A3F80A9D6C630F9E7D239B437F7402DF8055069735894CD9D4708F8777B5E4F3E6A8B2D4EEE50DB2C96BA16D3C81FEB923697D649A8B7771B10E5B3F"; 
    string Q = "00B5AF039839043410E04C35BDDB30679969EBAC8B"; 
    string G = "00F300A68E54DE33A09001E28EC09F2ABF5DAF208774F2514D878D5587D870C91C6DE42B4705078C6F4438765050039C2950B6DE85AFC0D12A7A5C521782CB760918DF68F385A7F177DF50AA6BA0284090454106E422FCAE5390ADC00B859A433430019E970BFA614374DE1FB40C600345EF19DC01A122E4676C614DC29D3DC2FE"; 
    string Y = "00A5317849AF22BA6498F1EF973158C8BDA848BEB074CB141E629C927B18F29C8CE99815001BAAB2931F339B5C52A79BC3DCB0C5962C302707BA6FF1807EEB91D751BA723BB7512C20689AC5E67A1B656CDFD1BA2D4F6A44308509486AA8754B47784FC4C03E546897200388656BA5834A2CC0E18E58454FF60C1BA5411D6F50FD"; 

    var publicKey = 
       ToMPI(HexToBytes(P)) 
     .Concat(ToMPI(HexToBytes(Q))) 
     .Concat(ToMPI(HexToBytes(G))) 
     .Concat(ToMPI(HexToBytes(Y))) 
     .ToArray(); 

    var fingerprint=BitConverter.ToString(SHA1.Create().ComputeHash(publicKey)).Replace("-",""); 
    fingerprint.Dump(); 
} 

byte[] ToMPI(byte[] data) 
{ 
    //Truncate leading 0 bytes 
    data = data.SkipWhile(b=>b==0).ToArray(); 

    //Length prefix - 32 bit big-endian integer 
    var lenBytes=new byte[4]; 
    lenBytes[0]=(byte)(data.Length>>24); 
    lenBytes[1]=(byte)(data.Length>>16); 
    lenBytes[2]=(byte)(data.Length>>8); 
    lenBytes[3]=(byte)(data.Length>>0); 

    return lenBytes.Concat(data).ToArray(); 
} 

// from http://stackoverflow.com/questions/311165/how-do-you-convert-byte-array-to-hexadecimal-string-and-vice-versa 
public static byte[] HexToBytes(String hex) 
{ 
    int NumberChars = hex.Length; 
    byte[] bytes = new byte[NumberChars/2]; 
    for (int i = 0; i < NumberChars; i += 2) 
    bytes[i/2] = Convert.ToByte(hex.Substring(i, 2), 16); 
    return bytes; 
} 

Answer 2

MSDN提到你需要做this page你的工作是什么。 然后，从this SO page看看这个答案。接受的答案给出了下面的代码（和我的报价）：

var dsa = new DSACryptoServiceProvider();    
var privateKey = dsa.ExportParameters(true); // private key 
var publicKey = dsa.ExportParameters(false); // public key 

我认为你有你需要的一切让你去。

CHEERS！