此Demo包含兩個文件，建立一個解決方案，然后建立兩個文件，一個為Form，一個為Class，把代碼分別復制進去即可

RSA正確的執行過程：
加密解密：
1、獲取密鑰，這里是產生密鑰，實際應用中可以從各種存儲介質上讀取密鑰
2、加密
3、解密
簽名和驗證：
簽名：
1、獲取密鑰，這里是產生密鑰，實際應用中可以從各種存儲介質上讀取密鑰
2、獲取待簽名的Hash碼
3、簽名
其中，1和2的步驟無所謂，在本例中，我們將對txtSource里的內容進行簽名，也可以對文件進行簽名
驗證簽名：
1、獲取密鑰，這里是產生密鑰，實際應用中可以從各種存儲介質上讀取密鑰
2、獲取待驗證簽名的Hash碼
3、獲取簽名的字串，這里簽名的字串存儲在m_strEncryptedSignatureData變量中，在DEMO中必須通過簽名才能獲得這個字串，因此需要先執行簽名，當然也可以更改之后通過別的方式獲得
4、驗證
其中，1和2的步驟無所謂，在本例中，我們將對txtSource里的內容進行簽名驗證，也可以對文件進行簽名驗證
 如果是文件，取得文件之后把文件的內容以byte[]的方式代入即可
///////////////////////////////////////////////////////////////////////////////////////////////////////////
//RSACryption.cs
///////////////////////////////////////////////////////////////////////////////////////////////////////////
using System;
using System.Text;
using System.Security.Cryptography;

namespace RSAApplication
{
 /// <summary>
 /// RSACryption 的摘要說明。
 /// </summary>
 public class RSACryption
 {
  #region 構造函數

  public RSACryption()
  {
   //
   // TODO: 在此處添加構造函數邏輯
   //
  }
  #endregion
  
  #region RSA 加密解密

  #region RSA 的密鑰產生
  //RSA 的密鑰產生
  //產生私鑰 和公鑰
  public void RSAKey(out string xmlKeys,out string  xmlPublicKey)
  {
   try
   {
    System.Security.Cryptography.RSACryptoServiceProvider rsa=new RSACryptoServiceProvider();
    xmlKeys=rsa.ToXmlString(true);
    xmlPublicKey = rsa.ToXmlString(false);
   }
   catch(Exception ex)
   {
    throw ex;
   }
  }
  #endregion
  #region RSA的加密函數
  //##############################################################################
  //RSA  方式加密 
  //說明KEY必須是XML的行式,返回的是字符串
  //在有一點需要說明！！該加密方式有 長度 限制的！！ 
  //##############################################################################

  //RSA的加密函數
  public string RSAEncrypt(string xmlPublicKey,string m_strEncryptString )
  {
   try
   {
    byte[] PlainTextBArray;
    byte[] CypherTextBArray;
    string Result;
    System.Security.Cryptography.RSACryptoServiceProvider rsa=new RSACryptoServiceProvider();
    rsa.FromXmlString(xmlPublicKey);
    PlainTextBArray = (new UnicodeEncoding()).GetBytes(m_strEncryptString);
    CypherTextBArray = rsa.Encrypt(PlainTextBArray, false);
    Result=Convert.ToBase64String(CypherTextBArray);
    return  Result;
   }
   catch(Exception ex)
   {
    throw ex;
   }
  }
  //RSA的加密函數
  public string RSAEncrypt(string xmlPublicKey,byte[] EncryptString )
  {
   try
   {
    byte[] CypherTextBArray;
    string Result;
    System.Security.Cryptography.RSACryptoServiceProvider rsa=new RSACryptoServiceProvider();
    rsa.FromXmlString(xmlPublicKey);
    CypherTextBArray = rsa.Encrypt(EncryptString, false);
    Result=Convert.ToBase64String(CypherTextBArray);
    return  Result;
   }
   catch(Exception ex)
   {
    throw ex;
   }
  }
  #endregion

  #region RSA的解密函數
  //RSA的解密函數
  public string  RSADecrypt(string xmlPrivateKey, string m_strDecryptString )
  {
   try
   {
    byte[] PlainTextBArray;
    byte[] DypherTextBArray;
    string Result;
    System.Security.Cryptography.RSACryptoServiceProvider rsa=new RSACryptoServiceProvider();
    rsa.FromXmlString(xmlPrivateKey);
    PlainTextBArray =Convert.FromBase64String(m_strDecryptString);
    DypherTextBArray=rsa.Decrypt(PlainTextBArray, false);
    Result=(new UnicodeEncoding()).GetString(DypherTextBArray);
    return Result;
   }
   catch(Exception ex)
   {
    throw ex;
   }
  }
 
  //RSA的解密函數
  public string  RSADecrypt(string xmlPrivateKey, byte[] DecryptString )
  {
   try
   {
    byte[] DypherTextBArray;
    string Result;
    System.Security.Cryptography.RSACryptoServiceProvider rsa=new RSACryptoServiceProvider();
    rsa.FromXmlString(xmlPrivateKey);
    DypherTextBArray=rsa.Decrypt(DecryptString, false);
    Result=(new UnicodeEncoding()).GetString(DypherTextBArray);
    return Result;
   }
   catch(Exception ex)
   {
    throw ex;
   }
  }
  #endregion

  #endregion

  #region RSA數字簽名

  #region 獲取Hash描述表
  //獲取Hash描述表
  public bool GetHash(string m_strSource, ref byte[] HashData)
  {
   try
   {
    //從字符串中取得Hash描述
    byte[] Buffer;
    System.Security.Cryptography.HashAlgorithm MD5 = System.Security.Cryptography.HashAlgorithm.Create("MD5");
    Buffer = System.Text.Encoding.GetEncoding("GB2312").GetBytes(m_strSource);
    HashData = MD5.ComputeHash(Buffer);
   
    return true;
   }
   catch(Exception ex)
   {
    throw ex;
   }
  }

  //獲取Hash描述表
  public bool GetHash(string m_strSource, ref string strHashData)
  {
   try
   {
    //從字符串中取得Hash描述
    byte[] Buffer;
    byte[] HashData;
    System.Security.Cryptography.HashAlgorithm MD5 = System.Security.Cryptography.HashAlgorithm.Create("MD5");
    Buffer = System.Text.Encoding.GetEncoding("GB2312").GetBytes(m_strSource);
    HashData = MD5.ComputeHash(Buffer);
   
    strHashData = Convert.ToBase64String(HashData);
    return true;
   }
   catch(Exception ex)
   {
    throw ex;
   }
  }

  //獲取Hash描述表
  public bool GetHash(System.IO.FileStream objFile, ref byte[] HashData)
  {
   try
   {
    //從文件中取得Hash描述
    System.Security.Cryptography.HashAlgorithm MD5 = System.Security.Cryptography.HashAlgorithm.Create("MD5");
    HashData = MD5.ComputeHash(objFile);
    objFile.Close();
   
    return true;
   }
   catch(Exception ex)
   {
    throw ex;
   }
  }

  //獲取Hash描述表
  public bool GetHash(System.IO.FileStream objFile, ref string strHashData)
  {
   try
   {
    //從文件中取得Hash描述
    byte[] HashData;
    System.Security.Cryptography.HashAlgorithm MD5 = System.Security.Cryptography.HashAlgorithm.Create("MD5");
    HashData = MD5.ComputeHash(objFile);
    objFile.Close();

    strHashData = Convert.ToBase64String(HashData);

    return true;
   }
   catch(Exception ex)
   {
    throw ex;
   }
  }
  #endregion

  #region RSA簽名
  //RSA簽名
  public bool SignatureFormatter(string p_strKeyPrivate, byte[] HashbyteSignature, ref byte[] EncryptedSignatureData)
  {
   try
   {
    System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();

    RSA.FromXmlString(p_strKeyPrivate);
    System.Security.Cryptography.RSAPKCS1SignatureFormatter RSAFormatter = new System.Security.Cryptography.RSAPKCS1SignatureFormatter(RSA);
    //設置簽名的算法為MD5
    RSAFormatter.SetHashAlgorithm("MD5");
    //執行簽名
    EncryptedSignatureData = RSAFormatter.CreateSignature(HashbyteSignature);

    return true;
   }
   catch(Exception ex)
   {
    throw ex;
   }
  }

  //RSA簽名
  public bool SignatureFormatter(string p_strKeyPrivate, byte[] HashbyteSignature, ref string m_strEncryptedSignatureData)
  {
   try
   {
    byte[] EncryptedSignatureData;

    System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();

    RSA.FromXmlString(p_strKeyPrivate);
    System.Security.Cryptography.RSAPKCS1SignatureFormatter RSAFormatter = new System.Security.Cryptography.RSAPKCS1SignatureFormatter(RSA);
    //設置簽名的算法為MD5
    RSAFormatter.SetHashAlgorithm("MD5");
    //執行簽名
    EncryptedSignatureData = RSAFormatter.CreateSignature(HashbyteSignature);

    m_strEncryptedSignatureData = Convert.ToBase64String(EncryptedSignatureData);

    return true;
   }
   catch(Exception ex)
   {
    throw ex;
   }
  }

  //RSA簽名
  public bool SignatureFormatter(string p_strKeyPrivate, string m_strHashbyteSignature, ref byte[] EncryptedSignatureData)
  {
   try
   {
    byte[] HashbyteSignature;

    HashbyteSignature = Convert.FromBase64String(m_strHashbyteSignature);
    System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();

    RSA.FromXmlString(p_strKeyPrivate);
    System.Security.Cryptography.RSAPKCS1SignatureFormatter RSAFormatter = new System.Security.Cryptography.RSAPKCS1SignatureFormatter(RSA);
    //設置簽名的算法為MD5
    RSAFormatter.SetHashAlgorithm("MD5");
    //執行簽名
    EncryptedSignatureData = RSAFormatter.CreateSignature(HashbyteSignature);

    return true;
   }
   catch(Exception ex)
   {
    throw ex;
   }
  }

  //RSA簽名
  public bool SignatureFormatter(string p_strKeyPrivate, string m_strHashbyteSignature, ref string m_strEncryptedSignatureData)
  {
   try
   {
    byte[] HashbyteSignature;
    byte[] EncryptedSignatureData;

    HashbyteSignature = Convert.FromBase64String(m_strHashbyteSignature);
    System.Security.Cryptography.RSACryptoServiceProvider RSA = new System.Security.Cryptography.RSACryptoServiceProvider();

    RSA.FromXmlString(p_strKeyPrivate);
    System.Security.Cryptography.RSAPKCS1SignatureFormatter RSAFormatter = new System.Security.Cryptography.RSAPKCS1SignatureFormatter(RSA);
    //設置簽名的算法為MD5
    RSAFormatter.SetHashAlgorithm("MD5");
    //執行簽名
    EncryptedSignatureData = RSAFormatter.CreateSignature(HashbyteSignature);

    m_strEncryptedSignatureData = Convert.ToBase64String(EncryptedSignatureData);

    return true;
   }
   catch(Exception ex)
   {
    throw ex;