protected void Button1_Click(object sender, EventArgs e)
    {
         using (RSACryptoServiceProvider rsa = new RSACryptoServiceProvider())         {             
             // 公钥            
             string pubkey = rsa.ToXmlString(false);    
             txtPublic.Text = pubkey;          
             // 私钥             
             string prikey = rsa.ToXmlString(true);            
             txtPrivate.Text = prikey;         }     
    }
    /// <summary>
    /// 加密
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    protected void Button2_Click(object sender, EventArgs e)
    {
        string prikey = txtPrivate.Text;         
        using (RSACryptoServiceProvider rsa = new RSACryptoServiceProvider())         
        { rsa.FromXmlString(prikey);             // 加密对象            
         RSAPKCS1SignatureFormatter f = new RSAPKCS1SignatureFormatter(rsa);             
            f.SetHashAlgorithm("SHA1");             
            byte[] source = System.Text.ASCIIEncoding.ASCII.GetBytes(sUserName.Text);             
            SHA1Managed sha = new SHA1Managed();             
            byte[] result = sha.ComputeHash(source);            
            byte[] b = f.CreateSignature(result);
            sCode.Text = Convert.ToBase64String(b);
        } 
    }
    /// <summary>
    /// 验证注册码
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    protected void Button3_Click(object sender, EventArgs e)
    {
        string pubkey = txtPublic.Text;        
        using (RSACryptoServiceProvider rsa = new RSACryptoServiceProvider())        
        {             rsa.FromXmlString(pubkey);           
            RSAPKCS1SignatureDeformatter f = new RSAPKCS1SignatureDeformatter(rsa);             
            f.SetHashAlgorithm("SHA1");            
            byte[] key = Convert.FromBase64String(cCode.Text);             
            SHA1Managed sha = new SHA1Managed();            
            byte[] name = sha.ComputeHash(ASCIIEncoding.ASCII.GetBytes(cUserName.Text));             
            if (f.VerifySignature(name, key))                 
                msg.Text = "验证成功";             
            else   msg.Text = "不成功";       
        }     
    } 
    }